Merge branch 'master' into on-demand-les-request

Cargo.lock

@@ -108,6 +108,17 @@ dependencies = [
  "syntex_syntax 0.42.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "bigint"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "heapsize 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "bit-set"
 version = "0.4.0"
@@ -377,10 +388,10 @@ dependencies = [
 name = "ethcore-bigint"
 version = "0.1.2"
 dependencies = [
+ "bigint 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1491,7 +1502,7 @@ dependencies = [
 [[package]]
 name = "parity-ui-precompiled"
 version = "1.4.0"
-source = "git+https://github.com/ethcore/js-precompiled.git#8d16476c138e94a643ad4624df9825f34b57e1b0"
+source = "git+https://github.com/ethcore/js-precompiled.git#d95a7dd2cc7469dc58af77743ec3ebc65e51cf36"
 dependencies = [
  "parity-dapps-glue 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2357,6 +2368,7 @@ dependencies = [
 "checksum arrayvec 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)" = "16e3bdb2f54b3ace0285975d59a97cf8ed3855294b2b6bc651fcf22a9c352975"
 "checksum aster 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)" = "07d344974f0a155f091948aa389fb1b912d3a58414fbdb9c8d446d193ee3496a"
 "checksum aster 0.25.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4df293303e8a52e1df7984ac1415e195f5fcbf51e4bb7bda54557861a3954a08"
+"checksum bigint 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2311bcd71b281e142a095311c22509f0d6bcd87b3000d7dbaa810929b9d6f6ae"
 "checksum bit-set 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d9bf6104718e80d7b26a68fdbacff3481cfc05df670821affc7e9cbc1884400c"
 "checksum bit-vec 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "5b97c2c8e8bbb4251754f559df8af22fb264853c7d009084a576cdf12565089d"
 "checksum bitflags 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8dead7461c1127cf637931a1e50934eb6eee8bff2f74433ac7909e9afcee04a3"

README.md

@@ -58,18 +58,18 @@ Parity is fully compatible with Stable Rust.
 
 We recommend installing Rust through [rustup](https://www.rustup.rs/). If you don't already have rustup, you can install it like this:
 
-- Linux and OSX:
+- Linux:
 	```bash
 	$ curl https://sh.rustup.rs -sSf | sh
 	```
 	
-	Parity also requires `gcc`, `g++` and `make` packages to be installed.
+	Parity also requires `gcc`, `g++`, `libssl-dev`/`openssl` and `pkg-config` packages to be installed.
 - OSX:
 	```bash
 	$ curl https://sh.rustup.rs -sSf | sh
 	```
 
-	`clang` and `make` are required. These come with Xcode command line tools or can be installed with homebrew.
+	`clang` is required. It comes with Xcode command line tools or can be installed with homebrew.
 - Windows
 
     Make sure you have Visual Studio 2015 with C++ support installed. Next, download and run the rustup installer from

dapps/Cargo.toml

@@ -9,7 +9,7 @@ build = "build.rs"
 [lib]
 
 [dependencies]
-rand = "0.3.14"
+rand = "0.3"
 log = "0.3"
 env_logger = "0.3"
 futures = "0.1"

dapps/src/apps/cache.rs

@@ -17,14 +17,13 @@
 //! Fetchable Dapps support.
 
 use std::fs;
-use std::sync::{Arc};
 
 use linked_hash_map::LinkedHashMap;
 use page::LocalPageEndpoint;
 use handlers::FetchControl;
 
 pub enum ContentStatus {
-	Fetching(Arc<FetchControl>),
+	Fetching(FetchControl),
 	Ready(LocalPageEndpoint),
 }
 

dapps/src/apps/fetcher/installers.rs

@@ -23,7 +23,7 @@ use util::H256;
 
 use util::sha3::sha3;
 use page::{LocalPageEndpoint, PageCache};
-use handlers::ContentValidator;
+use handlers::{ContentValidator, ValidatorResponse};
 use apps::manifest::{MANIFEST_FILENAME, deserialize_manifest, serialize_manifest, Manifest};
 
 type OnDone = Box<Fn(Option<LocalPageEndpoint>) + Send>;
@@ -35,30 +35,30 @@ fn write_response_and_check_hash(
 	response: fetch::Response
 ) -> Result<(fs::File, PathBuf), ValidationError> {
 	// try to parse id
-	let id = try!(id.parse().map_err(|_| ValidationError::InvalidContentId));
+	let id = id.parse().map_err(|_| ValidationError::InvalidContentId)?;
 
 	// check if content exists
 	if content_path.exists() {
 		warn!(target: "dapps", "Overwriting existing content at 0x{:?}", id);
-		try!(fs::remove_dir_all(&content_path))
+		fs::remove_dir_all(&content_path)?
 	}
 
 	// create directory
-	try!(fs::create_dir_all(&content_path));
+	fs::create_dir_all(&content_path)?;
 
 	// append filename
 	content_path.push(filename);
 
 	// Now write the response
-	let mut file = io::BufWriter::new(try!(fs::File::create(&content_path)));
+	let mut file = io::BufWriter::new(fs::File::create(&content_path)?);
 	let mut reader = io::BufReader::new(response);
-	try!(io::copy(&mut reader, &mut file));
+	io::copy(&mut reader, &mut file)?;
-	try!(file.flush());
+	file.flush()?;
 
 	// Validate hash
 	// TODO [ToDr] calculate sha3 in-flight while reading the response
-	let mut file = io::BufReader::new(try!(fs::File::open(&content_path)));
+	let mut file = io::BufReader::new(fs::File::open(&content_path)?);
-	let hash = try!(sha3(&mut file));
+	let hash = sha3(&mut file)?;
 	if id == hash {
 		Ok((file.into_inner(), content_path))
 	} else {
@@ -90,10 +90,10 @@ impl Content {
 impl ContentValidator for Content {
 	type Error = ValidationError;
 
-	fn validate_and_install(&self, response: fetch::Response) -> Result<LocalPageEndpoint, ValidationError> {
+	fn validate_and_install(&self, response: fetch::Response) -> Result<ValidatorResponse, ValidationError> {
 		let validate = |content_path: PathBuf| {
 			// Create dir
-			let (_, content_path) = try!(write_response_and_check_hash(self.id.as_str(), content_path.clone(), self.id.as_str(), response));
+			let (_, content_path) = write_response_and_check_hash(self.id.as_str(), content_path.clone(), self.id.as_str(), response)?;
 
 			Ok(LocalPageEndpoint::single_file(content_path, self.mime.clone(), PageCache::Enabled))
 		};
@@ -108,7 +108,7 @@ impl ContentValidator for Content {
 			let _ = fs::remove_dir_all(&content_path);
 		}
 		(self.on_done)(result.as_ref().ok().cloned());
-		result
+		result.map(ValidatorResponse::Local)
 	}
 }
 
@@ -131,7 +131,7 @@ impl Dapp {
 
 	fn find_manifest(zip: &mut zip::ZipArchive<fs::File>) -> Result<(Manifest, PathBuf), ValidationError> {
 		for i in 0..zip.len() {
-			let mut file = try!(zip.by_index(i));
+			let mut file = zip.by_index(i)?;
 
 			if !file.name().ends_with(MANIFEST_FILENAME) {
 				continue;
@@ -157,20 +157,20 @@ impl Dapp {
 impl ContentValidator for Dapp {
 	type Error = ValidationError;
 
-	fn validate_and_install(&self, response: fetch::Response) -> Result<LocalPageEndpoint, ValidationError> {
+	fn validate_and_install(&self, response: fetch::Response) -> Result<ValidatorResponse, ValidationError> {
 		let validate = |dapp_path: PathBuf| {
-			let (file, zip_path) = try!(write_response_and_check_hash(self.id.as_str(), dapp_path.clone(), &format!("{}.zip", self.id), response));
+			let (file, zip_path) = write_response_and_check_hash(self.id.as_str(), dapp_path.clone(), &format!("{}.zip", self.id), response)?;
 			trace!(target: "dapps", "Opening dapp bundle at {:?}", zip_path);
 			// Unpack archive
-			let mut zip = try!(zip::ZipArchive::new(file));
+			let mut zip = zip::ZipArchive::new(file)?;
 			// First find manifest file
-			let (mut manifest, manifest_dir) = try!(Self::find_manifest(&mut zip));
+			let (mut manifest, manifest_dir) = Self::find_manifest(&mut zip)?;
 			// Overwrite id to match hash
 			manifest.id = self.id.clone();
 
 			// Unpack zip
 			for i in 0..zip.len() {
-				let mut file = try!(zip.by_index(i));
+				let mut file = zip.by_index(i)?;
 				let is_dir = file.name().chars().rev().next() == Some('/');
 
 				let file_path = PathBuf::from(file.name());
@@ -180,22 +180,22 @@ impl ContentValidator for Dapp {
 					let p = dapp_path.join(location_in_manifest_base);
 					// Check if it's a directory
 					if is_dir {
-						try!(fs::create_dir_all(p));
+						fs::create_dir_all(p)?;
 					} else {
-						let mut target = try!(fs::File::create(p));
+						let mut target = fs::File::create(p)?;
-						try!(io::copy(&mut file, &mut target));
+						io::copy(&mut file, &mut target)?;
 					}
 				}
 			}
 
 			// Remove zip
-			try!(fs::remove_file(&zip_path));
+			fs::remove_file(&zip_path)?;
 
 			// Write manifest
-			let manifest_str = try!(serialize_manifest(&manifest).map_err(ValidationError::ManifestSerialization));
+			let manifest_str = serialize_manifest(&manifest).map_err(ValidationError::ManifestSerialization)?;
 			let manifest_path = dapp_path.join(MANIFEST_FILENAME);
-			let mut manifest_file = try!(fs::File::create(manifest_path));
+			let mut manifest_file = fs::File::create(manifest_path)?;
-			try!(manifest_file.write_all(manifest_str.as_bytes()));
+			manifest_file.write_all(manifest_str.as_bytes())?;
 			// Create endpoint
 			let endpoint = LocalPageEndpoint::new(dapp_path, manifest.clone().into(), PageCache::Enabled, self.embeddable_on.clone());
 			Ok(endpoint)
@@ -211,7 +211,7 @@ impl ContentValidator for Dapp {
 			let _ = fs::remove_dir_all(&target);
 		}
 		(self.on_done)(result.as_ref().ok().cloned());
-		result
+		result.map(ValidatorResponse::Local)
 	}
 }
 

dapps/src/apps/fetcher/mod.rs

@@ -129,12 +129,12 @@ impl<R: URLHint + Send + Sync + 'static, F: Fetch> Fetcher for ContentFetcher<F,
 					(None, endpoint.to_async_handler(path, control))
 				},
 				// Content is already being fetched
-				Some(&mut ContentStatus::Fetching(ref fetch_control)) => {
+				Some(&mut ContentStatus::Fetching(ref fetch_control)) if !fetch_control.is_deadline_reached() => {
 					trace!(target: "dapps", "Content fetching in progress. Waiting...");
 					(None, fetch_control.to_async_handler(path, control))
 				},
 				// We need to start fetching the content
-				None => {
+				_ => {
 					trace!(target: "dapps", "Content unavailable. Fetching... {:?}", content_id);
 					let content_hex = content_id.from_hex().expect("to_handler is called only when `contains` returns true.");
 					let content = self.resolver.resolve(content_hex);
@@ -156,7 +156,7 @@ impl<R: URLHint + Send + Sync + 'static, F: Fetch> Fetcher for ContentFetcher<F,
 							(None, Self::still_syncing(self.embeddable_on.clone()))
 						},
 						Some(URLHintResult::Dapp(dapp)) => {
-							let (handler, fetch_control) = ContentFetcherHandler::new(
+							let handler = ContentFetcherHandler::new(
 								dapp.url(),
 								path,
 								control,
@@ -171,10 +171,10 @@ impl<R: URLHint + Send + Sync + 'static, F: Fetch> Fetcher for ContentFetcher<F,
 								self.fetch.clone(),
 							);
 
-							(Some(ContentStatus::Fetching(fetch_control)), Box::new(handler) as Box<Handler>)
+							(Some(ContentStatus::Fetching(handler.fetch_control())), Box::new(handler) as Box<Handler>)
 						},
 						Some(URLHintResult::Content(content)) => {
-							let (handler, fetch_control) = ContentFetcherHandler::new(
+							let handler = ContentFetcherHandler::new(
 								content.url,
 								path,
 								control,
@@ -189,7 +189,7 @@ impl<R: URLHint + Send + Sync + 'static, F: Fetch> Fetcher for ContentFetcher<F,
 								self.fetch.clone(),
 							);
 
-							(Some(ContentStatus::Fetching(fetch_control)), Box::new(handler) as Box<Handler>)
+							(Some(ContentStatus::Fetching(handler.fetch_control())), Box::new(handler) as Box<Handler>)
 						},
 						None if self.sync.is_major_importing() => {
 							(None, Self::still_syncing(self.embeddable_on.clone()))
@@ -224,7 +224,7 @@ mod tests {
 	use std::env;
 	use std::sync::Arc;
 	use util::Bytes;
-	use fetch::Client;
+	use fetch::{Fetch, Client};
 	use hash_fetch::urlhint::{URLHint, URLHintResult};
 	use parity_reactor::Remote;
 

dapps/src/apps/fs.rs

@@ -37,8 +37,8 @@ fn local_dapps(dapps_path: String) -> Vec<LocalDapp> {
 
 	let files = files.expect("Check is done earlier");
 	files.map(|dir| {
-			let entry = try!(dir);
+			let entry = dir?;
-			let file_type = try!(entry.file_type());
+			let file_type = entry.file_type()?;
 
 			// skip files
 			if file_type.is_file() {
@@ -79,7 +79,7 @@ fn read_manifest(name: &str, mut path: PathBuf) -> EndpointInfo {
 		.and_then(|mut f| {
 			// Reat file
 			let mut s = String::new();
-			try!(f.read_to_string(&mut s).map_err(|e| format!("{:?}", e)));
+			f.read_to_string(&mut s).map_err(|e| format!("{:?}", e))?;
 			// Try to deserialize manifest
 			deserialize_manifest(s)
 		})

dapps/src/apps/mod.rs

@@ -14,6 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
+use std::sync::Arc;
 use endpoint::{Endpoints, Endpoint};
 use page::PageEndpoint;
 use proxypac::ProxyPac;
@@ -21,6 +22,7 @@ use web::Web;
 use fetch::Fetch;
 use parity_dapps::WebApp;
 use parity_reactor::Remote;
+use {WebProxyTokens};
 
 mod cache;
 mod fs;
@@ -40,14 +42,20 @@ pub fn utils() -> Box<Endpoint> {
 	Box::new(PageEndpoint::with_prefix(parity_ui::App::default(), UTILS_PATH.to_owned()))
 }
 
-pub fn all_endpoints<F: Fetch>(dapps_path: String, signer_address: Option<(String, u16)>, remote: Remote, fetch: F) -> Endpoints {
+pub fn all_endpoints<F: Fetch>(
+	dapps_path: String,
+	signer_address: Option<(String, u16)>,
+	web_proxy_tokens: Arc<WebProxyTokens>,
+	remote: Remote,
+	fetch: F,
+) -> Endpoints {
 	// fetch fs dapps at first to avoid overwriting builtins
 	let mut pages = fs::local_endpoints(dapps_path, signer_address.clone());
 
 	// NOTE [ToDr] Dapps will be currently embeded on 8180
 	insert::<parity_ui::App>(&mut pages, "ui", Embeddable::Yes(signer_address.clone()));
-	pages.insert("proxy".into(), ProxyPac::boxed(signer_address));
+	pages.insert("proxy".into(), ProxyPac::boxed(signer_address.clone()));
-	pages.insert(WEB_PATH.into(), Web::boxed(remote, fetch));
+	pages.insert(WEB_PATH.into(), Web::boxed(signer_address.clone(), web_proxy_tokens.clone(), remote.clone(), fetch.clone()));
 
 	pages
 }

dapps/src/handlers/fetch.rs

@@ -31,33 +31,41 @@ use hyper::uri::RequestUri;
 use hyper::status::StatusCode;
 
 use endpoint::EndpointPath;
-use handlers::ContentHandler;
+use handlers::{ContentHandler, StreamingHandler};
 use page::{LocalPageEndpoint, PageHandlerWaiting};
 
 const FETCH_TIMEOUT: u64 = 30;
 
+pub enum ValidatorResponse {
+	Local(LocalPageEndpoint),
+	Streaming(StreamingHandler<fetch::Response>),
+}
+
+pub trait ContentValidator: Send + 'static {
+	type Error: fmt::Debug + fmt::Display;
+
+	fn validate_and_install(&self, fetch::Response) -> Result<ValidatorResponse, Self::Error>;
+}
+
 enum FetchState {
 	Waiting,
 	NotStarted(String),
 	Error(ContentHandler),
 	InProgress(mpsc::Receiver<FetchState>),
+	Streaming(StreamingHandler<fetch::Response>),
 	Done(LocalPageEndpoint, Box<PageHandlerWaiting>),
 }
 
 enum WaitResult {
 	Error(ContentHandler),
 	Done(LocalPageEndpoint),
+	NonAwaitable,
 }
 
-pub trait ContentValidator: Send + 'static {
+#[derive(Clone)]
-	type Error: fmt::Debug + fmt::Display;
-
-	fn validate_and_install(&self, fetch::Response) -> Result<LocalPageEndpoint, Self::Error>;
-}
-
 pub struct FetchControl {
 	abort: Arc<AtomicBool>,
-	listeners: Mutex<Vec<(Control, mpsc::Sender<WaitResult>)>>,
+	listeners: Arc<Mutex<Vec<(Control, mpsc::Sender<WaitResult>)>>>,
 	deadline: Instant,
 }
 
@@ -65,7 +73,7 @@ impl Default for FetchControl {
 	fn default() -> Self {
 		FetchControl {
 			abort: Arc::new(AtomicBool::new(false)),
-			listeners: Mutex::new(Vec::new()),
+			listeners: Arc::new(Mutex::new(Vec::new())),
 			deadline: Instant::now() + Duration::from_secs(FETCH_TIMEOUT),
 		}
 	}
@@ -88,10 +96,15 @@ impl FetchControl {
 		match *status {
 			FetchState::Error(ref handler) => self.notify(|| WaitResult::Error(handler.clone())),
 			FetchState::Done(ref endpoint, _) => self.notify(|| WaitResult::Done(endpoint.clone())),
+			FetchState::Streaming(_) => self.notify(|| WaitResult::NonAwaitable),
 			FetchState::NotStarted(_) | FetchState::InProgress(_) | FetchState::Waiting => {},
 		}
 	}
 
+	pub fn is_deadline_reached(&self) -> bool {
+		self.deadline < Instant::now()
+	}
+
 	pub fn abort(&self) {
 		self.abort.store(true, Ordering::SeqCst);
 	}
@@ -131,7 +144,7 @@ impl server::Handler<HttpStream> for WaitingHandler {
 				page_handler.set_uri(&self.uri);
 				FetchState::Done(endpoint, page_handler)
 			},
-			None => {
+			_ => {
 				warn!("A result for waiting request was not received.");
 				FetchState::Waiting
 			},
@@ -139,6 +152,7 @@ impl server::Handler<HttpStream> for WaitingHandler {
 
 		match self.state {
 			FetchState::Done(_, ref mut handler) => handler.on_request_readable(decoder),
+			FetchState::Streaming(ref mut handler) => handler.on_request_readable(decoder),
 			FetchState::Error(ref mut handler) => handler.on_request_readable(decoder),
 			_ => Next::write(),
 		}
@@ -147,6 +161,7 @@ impl server::Handler<HttpStream> for WaitingHandler {
 	fn on_response(&mut self, res: &mut server::Response) -> Next {
 		match self.state {
 			FetchState::Done(_, ref mut handler) => handler.on_response(res),
+			FetchState::Streaming(ref mut handler) => handler.on_response(res),
 			FetchState::Error(ref mut handler) => handler.on_response(res),
 			_ => Next::end(),
 		}
@@ -155,22 +170,69 @@ impl server::Handler<HttpStream> for WaitingHandler {
 	fn on_response_writable(&mut self, encoder: &mut Encoder<HttpStream>) -> Next {
 		match self.state {
 			FetchState::Done(_, ref mut handler) => handler.on_response_writable(encoder),
+			FetchState::Streaming(ref mut handler) => handler.on_response_writable(encoder),
 			FetchState::Error(ref mut handler) => handler.on_response_writable(encoder),
 			_ => Next::end(),
 		}
 	}
 }
 
+#[derive(Clone)]
+struct Errors {
+	embeddable_on: Option<(String, u16)>,
+}
+
+impl Errors {
+	fn download_error<E: fmt::Debug>(&self, e: E) -> ContentHandler {
+		ContentHandler::error(
+			StatusCode::BadGateway,
+			"Download Error",
+			"There was an error when fetching the content.",
+			Some(&format!("{:?}", e)),
+			self.embeddable_on.clone(),
+		)
+	}
+
+	fn invalid_content<E: fmt::Debug>(&self, e: E) -> ContentHandler {
+		ContentHandler::error(
+			StatusCode::BadGateway,
+			"Invalid Dapp",
+			"Downloaded bundle does not contain a valid content.",
+			Some(&format!("{:?}", e)),
+			self.embeddable_on.clone(),
+		)
+	}
+
+	fn timeout_error(&self) -> ContentHandler {
+		ContentHandler::error(
+			StatusCode::GatewayTimeout,
+			"Download Timeout",
+			&format!("Could not fetch content within {} seconds.", FETCH_TIMEOUT),
+			None,
+			self.embeddable_on.clone(),
+		)
+	}
+
+	fn method_not_allowed(&self) -> ContentHandler {
+		ContentHandler::error(
+			StatusCode::MethodNotAllowed,
+			"Method Not Allowed",
+			"Only <code>GET</code> requests are allowed.",
+			None,
+			self.embeddable_on.clone(),
+		)
+	}
+}
+
 pub struct ContentFetcherHandler<H: ContentValidator, F: Fetch> {
-	fetch_control: Arc<FetchControl>,
+	fetch_control: FetchControl,
 	control: Control,
 	remote: Remote,
 	status: FetchState,
 	fetch: F,
 	installer: Option<H>,
 	path: EndpointPath,
-	uri: RequestUri,
+	errors: Errors,
-	embeddable_on: Option<(String, u16)>,
 }
 
 impl<H: ContentValidator, F: Fetch> ContentFetcherHandler<H, F> {
@@ -178,70 +240,64 @@ impl<H: ContentValidator, F: Fetch> ContentFetcherHandler<H, F> {
 		url: String,
 		path: EndpointPath,
 		control: Control,
-		handler: H,
+		installer: H,
 		embeddable_on: Option<(String, u16)>,
 		remote: Remote,
 		fetch: F,
-	) -> (Self, Arc<FetchControl>) {
+	) -> Self {
-		let fetch_control = Arc::new(FetchControl::default());
+		ContentFetcherHandler {
-		let handler = ContentFetcherHandler {
+			fetch_control: FetchControl::default(),
-			fetch_control: fetch_control.clone(),
 			control: control,
 			remote: remote,
 			fetch: fetch,
 			status: FetchState::NotStarted(url),
-			installer: Some(handler),
+			installer: Some(installer),
 			path: path,
-			uri: RequestUri::default(),
+			errors: Errors {
-			embeddable_on: embeddable_on,
+				embeddable_on: embeddable_on,
-		};
+			},
-
+		}
-		(handler, fetch_control)
 	}
 
-	fn fetch_content(&self, url: &str, installer: H) -> mpsc::Receiver<FetchState> {
+	pub fn fetch_control(&self) -> FetchControl {
+		self.fetch_control.clone()
+	}
+
+	fn fetch_content(&self, uri: RequestUri, url: &str, installer: H) -> mpsc::Receiver<FetchState> {
 		let (tx, rx) = mpsc::channel();
 		let abort = self.fetch_control.abort.clone();
 
-		let control = self.control.clone();
-		let embeddable_on = self.embeddable_on.clone();
-		let uri = self.uri.clone();
 		let path = self.path.clone();
+		let tx2 = tx.clone();
+		let control = self.control.clone();
+		let errors = self.errors.clone();
 
 		let future = self.fetch.fetch_with_abort(url, abort.into()).then(move |result| {
 			trace!(target: "dapps", "Fetching content finished. Starting validation: {:?}", result);
 			let new_state = match result {
 				Ok(response) => match installer.validate_and_install(response) {
-					Ok(endpoint) => {
+					Ok(ValidatorResponse::Local(endpoint)) => {
 						trace!(target: "dapps", "Validation OK. Returning response.");
 						let mut handler = endpoint.to_page_handler(path);
 						handler.set_uri(&uri);
 						FetchState::Done(endpoint, handler)
 					},
+					Ok(ValidatorResponse::Streaming(handler)) => {
+						trace!(target: "dapps", "Validation OK. Streaming response.");
+						FetchState::Streaming(handler)
+					},
 					Err(e) => {
 						trace!(target: "dapps", "Error while validating content: {:?}", e);
-						FetchState::Error(ContentHandler::error(
+						FetchState::Error(errors.invalid_content(e))
-							StatusCode::BadGateway,
-							"Invalid Dapp",
-							"Downloaded bundle does not contain a valid content.",
-							Some(&format!("{:?}", e)),
-							embeddable_on,
-						))
 					},
 				},
 				Err(e) => {
 					warn!(target: "dapps", "Unable to fetch content: {:?}", e);
-					FetchState::Error(ContentHandler::error(
+					FetchState::Error(errors.download_error(e))
-						StatusCode::BadGateway,
-						"Download Error",
-						"There was an error when fetching the content.",
-						Some(&format!("{:?}", e)),
-						embeddable_on,
-					))
 				},
 			};
 			// Content may be resolved when the connection is already dropped.
-			let _ = tx.send(new_state);
+			let _ = tx2.send(new_state);
 			// Ignoring control errors
 			let _ = control.ready(Next::read());
 			Ok(()) as Result<(), ()>
@@ -250,7 +306,14 @@ impl<H: ContentValidator, F: Fetch> ContentFetcherHandler<H, F> {
 		// make sure to run within fetch thread pool.
 		let future = self.fetch.process(future);
 		// spawn to event loop
-		self.remote.spawn(future);
+		let control = self.control.clone();
+		let errors = self.errors.clone();
+		self.remote.spawn_with_timeout(|| future, Duration::from_secs(FETCH_TIMEOUT), move || {
+			// Notify about the timeout
+			let _ = tx.send(FetchState::Error(errors.timeout_error()));
+			// Ignoring control errors
+			let _ = control.ready(Next::read());
+		});
 
 		rx
 	}
@@ -258,24 +321,19 @@ impl<H: ContentValidator, F: Fetch> ContentFetcherHandler<H, F> {
 
 impl<H: ContentValidator, F: Fetch> server::Handler<HttpStream> for ContentFetcherHandler<H, F> {
 	fn on_request(&mut self, request: server::Request<HttpStream>) -> Next {
-		self.uri = request.uri().clone();
-		let installer = self.installer.take().expect("Installer always set initialy; installer used only in on_request; on_request invoked only once; qed");
 		let status = if let FetchState::NotStarted(ref url) = self.status {
+			let uri = request.uri().clone();
+			let installer = self.installer.take().expect("Installer always set initialy; installer used only in on_request; on_request invoked only once; qed");
+
 			Some(match *request.method() {
 				// Start fetching content
 				Method::Get => {
 					trace!(target: "dapps", "Fetching content from: {:?}", url);
-					let receiver = self.fetch_content(url, installer);
+					let receiver = self.fetch_content(uri, url, installer);
 					FetchState::InProgress(receiver)
 				},
 				// or return error
-				_ => FetchState::Error(ContentHandler::error(
+				_ => FetchState::Error(self.errors.method_not_allowed()),
-					StatusCode::MethodNotAllowed,
-					"Method Not Allowed",
-					"Only <code>GET</code> requests are allowed.",
-					None,
-					self.embeddable_on.clone(),
-				)),
 			})
 		} else { None };
 
@@ -290,16 +348,9 @@ impl<H: ContentValidator, F: Fetch> server::Handler<HttpStream> for ContentFetch
 	fn on_request_readable(&mut self, decoder: &mut Decoder<HttpStream>) -> Next {
 		let (status, next) = match self.status {
 			// Request may time out
-			FetchState::InProgress(_) if self.fetch_control.deadline < Instant::now() => {
+			FetchState::InProgress(_) if self.fetch_control.is_deadline_reached() => {
 				trace!(target: "dapps", "Fetching dapp failed because of timeout.");
-				let timeout = ContentHandler::error(
+				(Some(FetchState::Error(self.errors.timeout_error())), Next::write())
-					StatusCode::GatewayTimeout,
-					"Download Timeout",
-					&format!("Could not fetch content within {} seconds.", FETCH_TIMEOUT),
-					None,
-					self.embeddable_on.clone(),
-				);
-				(Some(FetchState::Error(timeout)), Next::write())
 			},
 			FetchState::InProgress(ref receiver) => {
 				// Check if there is an answer
@@ -326,6 +377,7 @@ impl<H: ContentValidator, F: Fetch> server::Handler<HttpStream> for ContentFetch
 	fn on_response(&mut self, res: &mut server::Response) -> Next {
 		match self.status {
 			FetchState::Done(_, ref mut handler) => handler.on_response(res),
+			FetchState::Streaming(ref mut handler) => handler.on_response(res),
 			FetchState::Error(ref mut handler) => handler.on_response(res),
 			_ => Next::end(),
 		}
@@ -334,6 +386,7 @@ impl<H: ContentValidator, F: Fetch> server::Handler<HttpStream> for ContentFetch
 	fn on_response_writable(&mut self, encoder: &mut Encoder<HttpStream>) -> Next {
 		match self.status {
 			FetchState::Done(_, ref mut handler) => handler.on_response_writable(encoder),
+			FetchState::Streaming(ref mut handler) => handler.on_response_writable(encoder),
 			FetchState::Error(ref mut handler) => handler.on_response_writable(encoder),
 			_ => Next::end(),
 		}

dapps/src/handlers/mod.rs

@@ -17,16 +17,18 @@
 //! Hyper handlers implementations.
 
 mod auth;
-mod echo;
 mod content;
-mod redirect;
+mod echo;
 mod fetch;
+mod redirect;
+mod streaming;
 
 pub use self::auth::AuthRequiredHandler;
-pub use self::echo::EchoHandler;
 pub use self::content::ContentHandler;
+pub use self::echo::EchoHandler;
+pub use self::fetch::{ContentFetcherHandler, ContentValidator, FetchControl, ValidatorResponse};
 pub use self::redirect::Redirection;
-pub use self::fetch::{ContentFetcherHandler, ContentValidator, FetchControl};
+pub use self::streaming::StreamingHandler;
 
 use url::Url;
 use hyper::{server, header, net, uri};
@@ -49,20 +51,30 @@ pub fn add_security_headers(headers: &mut header::Headers, embeddable_on: Option
 	}
 }
 
+
 /// Extracts URL part from the Request.
 pub fn extract_url(req: &server::Request<net::HttpStream>) -> Option<Url> {
-	match *req.uri() {
+	convert_uri_to_url(req.uri(), req.headers().get::<header::Host>())
+}
+
+/// Extracts URL given URI and Host header.
+pub fn convert_uri_to_url(uri: &uri::RequestUri, host: Option<&header::Host>) -> Option<Url> {
+	match *uri {
 		uri::RequestUri::AbsoluteUri(ref url) => {
 			match Url::from_generic_url(url.clone()) {
 				Ok(url) => Some(url),
 				_ => None,
 			}
 		},
-		uri::RequestUri::AbsolutePath { ref path, .. } => {
+		uri::RequestUri::AbsolutePath { ref path, ref query } => {
+			let query = match *query {
+				Some(ref query) => format!("?{}", query),
+				None => "".into(),
+			};
 			// Attempt to prepend the Host header (mandatory in HTTP/1.1)
-			let url_string = match req.headers().get::<header::Host>() {
+			let url_string = match host {
 				Some(ref host) => {
-					format!("http://{}:{}{}", host.hostname, host.port.unwrap_or(80), path)
+					format!("http://{}:{}{}{}", host.hostname, host.port.unwrap_or(80), path, query)
 				},
 				None => return None,
 			};

dapps/src/handlers/streaming.rs

@@ -0,0 +1,101 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Content Stream Response
+
+use std::io::{self, Read};
+
+use hyper::{header, server, Decoder, Encoder, Next};
+use hyper::net::HttpStream;
+use hyper::mime::Mime;
+use hyper::status::StatusCode;
+
+use handlers::add_security_headers;
+
+const BUFFER_SIZE: usize = 1024;
+
+pub struct StreamingHandler<R: io::Read> {
+	buffer: [u8; BUFFER_SIZE],
+	buffer_leftover: usize,
+	status: StatusCode,
+	content: io::BufReader<R>,
+	mimetype: Mime,
+	safe_to_embed_on: Option<(String, u16)>,
+}
+
+impl<R: io::Read> StreamingHandler<R> {
+	pub fn new(content: R, status: StatusCode, mimetype: Mime, embeddable_on: Option<(String, u16)>) -> Self {
+		StreamingHandler {
+			buffer: [0; BUFFER_SIZE],
+			buffer_leftover: 0,
+			status: status,
+			content: io::BufReader::new(content),
+			mimetype: mimetype,
+			safe_to_embed_on: embeddable_on,
+		}
+	}
+
+	pub fn set_initial_content(&mut self, content: &str) {
+		assert_eq!(self.buffer_leftover, 0);
+		let bytes = content.as_bytes();
+		self.buffer_leftover = bytes.len();
+		self.buffer[0..self.buffer_leftover].copy_from_slice(bytes);
+	}
+}
+
+impl<R: io::Read> server::Handler<HttpStream> for StreamingHandler<R> {
+	fn on_request(&mut self, _request: server::Request<HttpStream>) -> Next {
+		Next::write()
+	}
+
+	fn on_request_readable(&mut self, _decoder: &mut Decoder<HttpStream>) -> Next {
+		Next::write()
+	}
+
+	fn on_response(&mut self, res: &mut server::Response) -> Next {
+		res.set_status(self.status);
+		res.headers_mut().set(header::ContentType(self.mimetype.clone()));
+		add_security_headers(&mut res.headers_mut(), self.safe_to_embed_on.clone());
+		Next::write()
+	}
+
+	fn on_response_writable(&mut self, encoder: &mut Encoder<HttpStream>) -> Next {
+		fn handle_error(e: io::Error) -> Next {
+			match e.kind() {
+				::std::io::ErrorKind::WouldBlock => Next::write(),
+				_ => Next::end(),
+			}
+		}
+
+		let write_pos = self.buffer_leftover;
+		match self.content.read(&mut self.buffer[write_pos..]) {
+			Err(e) => handle_error(e),
+			Ok(read) => match encoder.write(&self.buffer[..write_pos + read]) {
+				Err(e) => handle_error(e),
+				Ok(0) => Next::end(),
+				Ok(wrote) => {
+					self.buffer_leftover = write_pos + read - wrote;
+					if self.buffer_leftover > 0 {
+						for i in self.buffer_leftover..write_pos + read {
+							self.buffer.swap(i, i - self.buffer_leftover);
+						}
+					}
+					Next::write()
+				},
+			},
+		}
+	}
+}

dapps/src/lib.rs

@@ -111,18 +111,29 @@ impl<F> SyncStatus for F where F: Fn() -> bool + Send + Sync {
 	fn is_major_importing(&self) -> bool { self() }
 }
 
+/// Validates Web Proxy tokens
+pub trait WebProxyTokens: Send + Sync {
+	/// Should return true if token is a valid web proxy access token.
+	fn is_web_proxy_token_valid(&self, token: &String) -> bool;
+}
+
+impl<F> WebProxyTokens for F where F: Fn(String) -> bool + Send + Sync {
+	fn is_web_proxy_token_valid(&self, token: &String) -> bool { self(token.to_owned()) }
+}
+
 /// Webapps HTTP+RPC server build.
-pub struct ServerBuilder {
+pub struct ServerBuilder<T: Fetch = FetchClient> {
 	dapps_path: String,
 	handler: Arc<IoHandler>,
 	registrar: Arc<ContractClient>,
 	sync_status: Arc<SyncStatus>,
+	web_proxy_tokens: Arc<WebProxyTokens>,
 	signer_address: Option<(String, u16)>,
 	remote: Remote,
-	fetch: Option<FetchClient>,
+	fetch: Option<T>,
 }
 
-impl Extendable for ServerBuilder {
+impl<T: Fetch> Extendable for ServerBuilder<T> {
 	fn add_delegate<D: Send + Sync + 'static>(&self, delegate: IoDelegate<D>) {
 		self.handler.add_delegate(delegate);
 	}
@@ -136,30 +147,50 @@ impl ServerBuilder {
 			handler: Arc::new(IoHandler::new()),
 			registrar: registrar,
 			sync_status: Arc::new(|| false),
+			web_proxy_tokens: Arc::new(|_| false),
 			signer_address: None,
 			remote: remote,
 			fetch: None,
 		}
 	}
+}
 
+impl<T: Fetch> ServerBuilder<T> {
 	/// Set a fetch client to use.
-	pub fn with_fetch(&mut self, fetch: FetchClient) {
+	pub fn fetch<X: Fetch>(self, fetch: X) -> ServerBuilder<X> {
-		self.fetch = Some(fetch);
+		ServerBuilder {
+			dapps_path: self.dapps_path,
+			handler: self.handler,
+			registrar: self.registrar,
+			sync_status: self.sync_status,
+			web_proxy_tokens: self.web_proxy_tokens,
+			signer_address: self.signer_address,
+			remote: self.remote,
+			fetch: Some(fetch),
+		}
 	}
 
 	/// Change default sync status.
-	pub fn with_sync_status(&mut self, status: Arc<SyncStatus>) {
+	pub fn sync_status(mut self, status: Arc<SyncStatus>) -> Self {
 		self.sync_status = status;
+		self
+	}
+
+	/// Change default web proxy tokens validator.
+	pub fn web_proxy_tokens(mut self, tokens: Arc<WebProxyTokens>) -> Self {
+		self.web_proxy_tokens = tokens;
+		self
 	}
 
 	/// Change default signer port.
-	pub fn with_signer_address(&mut self, signer_address: Option<(String, u16)>) {
+	pub fn signer_address(mut self, signer_address: Option<(String, u16)>) -> Self {
 		self.signer_address = signer_address;
+		self
 	}
 
 	/// Asynchronously start server with no authentication,
 	/// returns result with `Server` handle on success or an error.
-	pub fn start_unsecured_http(&self, addr: &SocketAddr, hosts: Option<Vec<String>>) -> Result<Server, ServerError> {
+	pub fn start_unsecured_http(self, addr: &SocketAddr, hosts: Option<Vec<String>>) -> Result<Server, ServerError> {
 		Server::start_http(
 			addr,
 			hosts,
@@ -169,14 +200,15 @@ impl ServerBuilder {
 			self.signer_address.clone(),
 			self.registrar.clone(),
 			self.sync_status.clone(),
+			self.web_proxy_tokens.clone(),
 			self.remote.clone(),
-			try!(self.fetch()),
+			self.fetch_client()?,
 		)
 	}
 
 	/// Asynchronously start server with `HTTP Basic Authentication`,
 	/// return result with `Server` handle on success or an error.
-	pub fn start_basic_auth_http(&self, addr: &SocketAddr, hosts: Option<Vec<String>>, username: &str, password: &str) -> Result<Server, ServerError> {
+	pub fn start_basic_auth_http(self, addr: &SocketAddr, hosts: Option<Vec<String>>, username: &str, password: &str) -> Result<Server, ServerError> {
 		Server::start_http(
 			addr,
 			hosts,
@@ -186,15 +218,16 @@ impl ServerBuilder {
 			self.signer_address.clone(),
 			self.registrar.clone(),
 			self.sync_status.clone(),
+			self.web_proxy_tokens.clone(),
 			self.remote.clone(),
-			try!(self.fetch()),
+			self.fetch_client()?,
 		)
 	}
 
-	fn fetch(&self) -> Result<FetchClient, ServerError> {
+	fn fetch_client(&self) -> Result<T, ServerError> {
 		match self.fetch.clone() {
 			Some(fetch) => Ok(fetch),
-			None => FetchClient::new().map_err(|_| ServerError::FetchInitialization),
+			None => T::new().map_err(|_| ServerError::FetchInitialization),
 		}
 	}
 }
@@ -241,6 +274,7 @@ impl Server {
 		signer_address: Option<(String, u16)>,
 		registrar: Arc<ContractClient>,
 		sync_status: Arc<SyncStatus>,
+		web_proxy_tokens: Arc<WebProxyTokens>,
 		remote: Remote,
 		fetch: F,
 	) -> Result<Server, ServerError> {
@@ -253,7 +287,7 @@ impl Server {
 			remote.clone(),
 			fetch.clone(),
 		));
-		let endpoints = Arc::new(apps::all_endpoints(dapps_path, signer_address.clone(), remote.clone(), fetch.clone()));
+		let endpoints = Arc::new(apps::all_endpoints(dapps_path, signer_address.clone(), web_proxy_tokens, remote.clone(), fetch.clone()));
 		let cors_domains = Self::cors_domains(signer_address.clone());
 
 		let special = Arc::new({
@@ -268,7 +302,7 @@ impl Server {
 		});
 		let hosts = Self::allowed_hosts(hosts, format!("{}", addr));
 
-		try!(hyper::Server::http(addr))
+		hyper::Server::http(addr)?
 			.handle(move |ctrl| router::Router::new(
 				ctrl,
 				signer_address.clone(),

dapps/src/router/mod.rs

@@ -21,15 +21,16 @@ pub mod auth;
 mod host_validation;
 
 use address;
+use std::cmp;
 use std::sync::Arc;
 use std::collections::HashMap;
 use url::{Url, Host};
-use hyper::{self, server, Next, Encoder, Decoder, Control, StatusCode};
+use hyper::{self, server, header, Next, Encoder, Decoder, Control, StatusCode};
 use hyper::net::HttpStream;
 use apps::{self, DAPPS_DOMAIN};
 use apps::fetcher::Fetcher;
 use endpoint::{Endpoint, Endpoints, EndpointPath};
-use handlers::{Redirection, extract_url, ContentHandler};
+use handlers::{self, Redirection, ContentHandler};
 use self::auth::{Authorization, Authorized};
 
 /// Special endpoints are accessible on every domain (every dapp)
@@ -57,9 +58,11 @@ impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 	fn on_request(&mut self, req: server::Request<HttpStream>) -> Next {
 
 		// Choose proper handler depending on path / domain
-		let url = extract_url(&req);
+		let url = handlers::extract_url(&req);
 		let endpoint = extract_endpoint(&url);
+		let referer = extract_referer_endpoint(&req);
 		let is_utils = endpoint.1 == SpecialEndpoint::Utils;
+		let is_get_request = *req.method() == hyper::Method::Get;
 
 		trace!(target: "dapps", "Routing request to {:?}. Details: {:?}", url, req);
 
@@ -83,25 +86,42 @@ impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 			return self.handler.on_request(req);
 		}
 
+
 		let control = self.control.take().expect("on_request is called only once; control is always defined at start; qed");
 		debug!(target: "dapps", "Handling endpoint request: {:?}", endpoint);
-		self.handler = match endpoint {
+		self.handler = match (endpoint.0, endpoint.1, referer) {
+			// Handle invalid web requests that we can recover from
+			(ref path, SpecialEndpoint::None, Some((ref referer, ref referer_url)))
+				if is_get_request
+					&& referer.app_id == apps::WEB_PATH
+					&& self.endpoints.contains_key(apps::WEB_PATH)
+					&& !is_web_endpoint(path)
+				=>
+			{
+				trace!(target: "dapps", "Redirecting to correct web request: {:?}", referer_url);
+				// TODO [ToDr] Some nice util for this!
+				let using_domain = if referer.using_dapps_domains { 0 } else { 1 };
+				let len = cmp::min(referer_url.path.len(), using_domain + 3); // token + protocol + hostname
+				let base = referer_url.path[..len].join("/");
+				let requested = url.map(|u| u.path.join("/")).unwrap_or_default();
+				Redirection::boxed(&format!("/{}/{}", base, requested))
+			},
 			// First check special endpoints
-			(ref path, ref endpoint) if self.special.contains_key(endpoint) => {
+			(ref path, ref endpoint, _) if self.special.contains_key(endpoint) => {
 				trace!(target: "dapps", "Resolving to special endpoint.");
 				self.special.get(endpoint)
 					.expect("special known to contain key; qed")
 					.to_async_handler(path.clone().unwrap_or_default(), control)
 			},
 			// Then delegate to dapp
-			(Some(ref path), _) if self.endpoints.contains_key(&path.app_id) => {
+			(Some(ref path), _, _) if self.endpoints.contains_key(&path.app_id) => {
 				trace!(target: "dapps", "Resolving to local/builtin dapp.");
 				self.endpoints.get(&path.app_id)
-					.expect("special known to contain key; qed")
+					.expect("endpoints known to contain key; qed")
 					.to_async_handler(path.clone(), control)
 			},
 			// Try to resolve and fetch the dapp
-			(Some(ref path), _) if self.fetch.contains(&path.app_id) => {
+			(Some(ref path), _, _) if self.fetch.contains(&path.app_id) => {
 				trace!(target: "dapps", "Resolving to fetchable content.");
 				self.fetch.to_async_handler(path.clone(), control)
 			},
@@ -110,7 +130,7 @@ impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 			// It should be safe to remove it in (near) future.
 			//
 			// 404 for non-existent content
-			(Some(ref path), _) if *req.method() == hyper::Method::Get && path.app_id != "home" => {
+			(Some(ref path), _, _) if is_get_request && path.app_id != "home" => {
 				trace!(target: "dapps", "Resolving to 404.");
 				Box::new(ContentHandler::error(
 					StatusCode::NotFound,
@@ -121,7 +141,7 @@ impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 				))
 			},
 			// Redirect any other GET request to signer.
-			_ if *req.method() == hyper::Method::Get => {
+			_ if is_get_request => {
 				if let Some(signer_address) = self.signer_address.clone() {
 					trace!(target: "dapps", "Redirecting to signer interface.");
 					Redirection::boxed(&format!("http://{}", address(signer_address)))
@@ -192,6 +212,23 @@ impl<A: Authorization> Router<A> {
 	}
 }
 
+fn is_web_endpoint(path: &Option<EndpointPath>) -> bool {
+	match *path {
+		Some(ref path) if path.app_id == apps::WEB_PATH => true,
+		_ => false,
+	}
+}
+
+fn extract_referer_endpoint(req: &server::Request<HttpStream>) -> Option<(EndpointPath, Url)> {
+	let referer = req.headers().get::<header::Referer>();
+
+	let url = referer.and_then(|referer| Url::parse(&referer.0).ok());
+	url.and_then(|url| {
+		let option = Some(url);
+		extract_endpoint(&option).0.map(|endpoint| (endpoint, option.expect("Just wrapped; qed")))
+	})
+}
+
 fn extract_endpoint(url: &Option<Url>) -> (Option<EndpointPath>, SpecialEndpoint) {
 	fn special_endpoint(url: &Url) -> SpecialEndpoint {
 		if url.path.len() <= 1 {

dapps/src/rpc.rs

@@ -51,16 +51,16 @@ impl Endpoint for RpcEndpoint {
 	}
 }
 
-const MIDDLEWARE_METHOD: &'static str = "eth_accounts";
-
 struct RpcMiddleware {
 	handler: Arc<IoHandler>,
+	methods: Vec<String>,
 }
 
 impl RpcMiddleware {
 	fn new(handler: Arc<IoHandler>) -> Self {
 		RpcMiddleware {
 			handler: handler,
+			methods: vec!["eth_accounts".into(), "parity_accountsInfo".into()],
 		}
 	}
 
@@ -68,9 +68,9 @@ impl RpcMiddleware {
 	fn augment_request(&self, request: &mut Request, meta: Option<Meta>) {
 		use jsonrpc_core::{Call, Params, to_value};
 
-		fn augment_call(call: &mut Call, meta: Option<&Meta>) {
+		fn augment_call(call: &mut Call, meta: Option<&Meta>, methods: &Vec<String>) {
 			match (call, meta) {
-				(&mut Call::MethodCall(ref mut method_call), Some(meta)) if &method_call.method == MIDDLEWARE_METHOD => {
+				(&mut Call::MethodCall(ref mut method_call), Some(meta)) if methods.contains(&method_call.method) => {
 					let session = to_value(&meta.app_id);
 
 					let params = match method_call.params {
@@ -86,10 +86,10 @@ impl RpcMiddleware {
 		}
 
 		match *request {
-			Request::Single(ref mut call) => augment_call(call, meta.as_ref()),
+			Request::Single(ref mut call) => augment_call(call, meta.as_ref(), &self.methods),
 			Request::Batch(ref mut vec) => {
 				for mut call in vec {
-					augment_call(call, meta.as_ref())
+					augment_call(call, meta.as_ref(), &self.methods)
 				}
 			},
 		}

dapps/src/tests/fetch.rs

@@ -14,7 +14,13 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-use tests::helpers::{serve_with_registrar, serve_with_registrar_and_sync, request, assert_security_headers_for_embed};
+use devtools::http_client;
+use rustc_serialize::hex::FromHex;
+use tests::helpers::{
+	serve_with_registrar, serve_with_registrar_and_sync, serve_with_fetch,
+	serve_with_registrar_and_fetch, serve_with_registrar_and_fetch_and_threads,
+	request, assert_security_headers_for_embed,
+};
 
 #[test]
 fn should_resolve_dapp() {
@@ -32,7 +38,7 @@ fn should_resolve_dapp() {
 	);
 
 	// then
-	assert_eq!(response.status, "HTTP/1.1 404 Not Found".to_owned());
+	response.assert_status("HTTP/1.1 404 Not Found");
 	assert_eq!(registrar.calls.lock().len(), 2);
 	assert_security_headers_for_embed(&response.headers);
 }
@@ -41,14 +47,6 @@ fn should_resolve_dapp() {
 fn should_return_503_when_syncing_but_should_make_the_calls() {
 	// given
 	let (server, registrar) = serve_with_registrar_and_sync();
-	{
-		let mut responses = registrar.responses.lock();
-		let res1 = responses.get(0).unwrap().clone();
-		let res2 = responses.get(1).unwrap().clone();
-		// Registrar will be called twice - fill up the responses.
-		responses.push(res1);
-		responses.push(res2);
-	}
 
 	// when
 	let response = request(server,
@@ -61,7 +59,378 @@ fn should_return_503_when_syncing_but_should_make_the_calls() {
 	);
 
 	// then
-	assert_eq!(response.status, "HTTP/1.1 503 Service Unavailable".to_owned());
+	response.assert_status("HTTP/1.1 503 Service Unavailable");
 	assert_eq!(registrar.calls.lock().len(), 4);
 	assert_security_headers_for_embed(&response.headers);
 }
+
+const GAVCOIN_DAPP: &'static str = "00000000000000000000000000000000000000000000000000000000000000609faf32e1e3845e237cc6efd27187cee13b3b99db000000000000000000000000000000000000000000000000d8bd350823e28ff75e74a34215faefdc8a52fd8e00000000000000000000000000000000000000000000000000000000000000116761766f66796f726b2f676176636f696e000000000000000000000000000000";
+const GAVCOIN_ICON: &'static str = "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";
+
+#[test]
+fn should_return_502_on_hash_mismatch() {
+	// given
+	let (server, fetch, registrar) = serve_with_registrar_and_fetch();
+	let gavcoin = GAVCOIN_DAPP.from_hex().unwrap();
+	registrar.set_result(
+		"94f093625c06887d94d9fee0d5f9cc4aaa46f33d24d1c7e4b5237e7c37d547dd".parse().unwrap(),
+		Ok(gavcoin.clone())
+	);
+
+	// when
+	let response = request(server,
+		"\
+			GET / HTTP/1.1\r\n\
+			Host: 94f093625c06887d94d9fee0d5f9cc4aaa46f33d24d1c7e4b5237e7c37d547dd.parity\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	assert_eq!(registrar.calls.lock().len(), 4);
+
+	fetch.assert_requested("https://codeload.github.com/gavofyork/gavcoin/zip/9faf32e1e3845e237cc6efd27187cee13b3b99db");
+	fetch.assert_no_more_requests();
+
+	response.assert_status("HTTP/1.1 502 Bad Gateway");
+	assert!(response.body.contains("HashMismatch"), "Expected hash mismatch response, got: {:?}", response.body);
+	assert_security_headers_for_embed(&response.headers);
+}
+
+#[test]
+fn should_return_error_for_invalid_dapp_zip() {
+	// given
+	let (server, fetch, registrar) = serve_with_registrar_and_fetch();
+	let gavcoin = GAVCOIN_DAPP.from_hex().unwrap();
+	registrar.set_result(
+		"2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e".parse().unwrap(),
+		Ok(gavcoin.clone())
+	);
+
+	// when
+	let response = request(server,
+		"\
+			GET / HTTP/1.1\r\n\
+			Host: 2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e.parity\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	assert_eq!(registrar.calls.lock().len(), 4);
+
+	fetch.assert_requested("https://codeload.github.com/gavofyork/gavcoin/zip/9faf32e1e3845e237cc6efd27187cee13b3b99db");
+	fetch.assert_no_more_requests();
+
+	response.assert_status("HTTP/1.1 502 Bad Gateway");
+	assert!(response.body.contains("InvalidArchive"), "Expected invalid zip response, got: {:?}", response.body);
+	assert_security_headers_for_embed(&response.headers);
+}
+
+#[test]
+fn should_return_fetched_dapp_content() {
+	// given
+	let (server, fetch, registrar) = serve_with_registrar_and_fetch();
+	let gavcoin = GAVCOIN_DAPP.from_hex().unwrap();
+	registrar.set_result(
+		"9c94e154dab8acf859b30ee80fc828fb1d38359d938751b65db71d460588d82a".parse().unwrap(),
+		Ok(gavcoin.clone())
+	);
+	fetch.set_response(include_bytes!("../../res/gavcoin.zip"));
+
+	// when
+	let response1 = http_client::request(server.addr(),
+		"\
+			GET /index.html HTTP/1.1\r\n\
+			Host: 9c94e154dab8acf859b30ee80fc828fb1d38359d938751b65db71d460588d82a.parity\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+	let response2 = http_client::request(server.addr(),
+		"\
+			GET /manifest.json HTTP/1.1\r\n\
+			Host: 9c94e154dab8acf859b30ee80fc828fb1d38359d938751b65db71d460588d82a.parity\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	assert_eq!(registrar.calls.lock().len(), 4);
+
+	fetch.assert_requested("https://codeload.github.com/gavofyork/gavcoin/zip/9faf32e1e3845e237cc6efd27187cee13b3b99db");
+	fetch.assert_no_more_requests();
+
+	response1.assert_status("HTTP/1.1 200 OK");
+	assert_security_headers_for_embed(&response1.headers);
+	assert_eq!(
+		response1.body,
+		r#"18
+<h1>Hello Gavcoin!</h1>
+
+"#
+	);
+
+	response2.assert_status("HTTP/1.1 200 OK");
+	assert_security_headers_for_embed(&response2.headers);
+	assert_eq!(
+		response2.body,
+		r#"BE
+{
+  "id": "9c94e154dab8acf859b30ee80fc828fb1d38359d938751b65db71d460588d82a",
+  "name": "Gavcoin",
+  "description": "Gavcoin",
+  "version": "1.0.0",
+  "author": "",
+  "iconUrl": "icon.png"
+}
+0
+
+"#
+	);
+}
+
+#[test]
+fn should_return_fetched_content() {
+	// given
+	let (server, fetch, registrar) = serve_with_registrar_and_fetch();
+	let gavcoin = GAVCOIN_ICON.from_hex().unwrap();
+	registrar.set_result(
+		"2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e".parse().unwrap(),
+		Ok(gavcoin.clone())
+	);
+
+	// when
+	let response = request(server,
+		"\
+			GET / HTTP/1.1\r\n\
+			Host: 2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e.parity\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	assert_eq!(registrar.calls.lock().len(), 4);
+
+	fetch.assert_requested("https://raw.githubusercontent.com/ethcore/dapp-assets/b88e983abaa1a6a6345b8d9448c15b117ddb540e/tokens/gavcoin-64x64.png");
+	fetch.assert_no_more_requests();
+
+	response.assert_status("HTTP/1.1 200 OK");
+	response.assert_security_headers_present(None);
+}
+
+#[test]
+fn should_cache_content() {
+	// given
+	let (server, fetch, registrar) = serve_with_registrar_and_fetch();
+	let gavcoin = GAVCOIN_ICON.from_hex().unwrap();
+	registrar.set_result(
+		"2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e".parse().unwrap(),
+		Ok(gavcoin.clone())
+	);
+	let request_str = "\
+		GET / HTTP/1.1\r\n\
+		Host: 2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e.parity\r\n\
+		Connection: close\r\n\
+		\r\n\
+	";
+
+	let response = http_client::request(server.addr(), request_str);
+	fetch.assert_requested("https://raw.githubusercontent.com/ethcore/dapp-assets/b88e983abaa1a6a6345b8d9448c15b117ddb540e/tokens/gavcoin-64x64.png");
+	fetch.assert_no_more_requests();
+	response.assert_status("HTTP/1.1 200 OK");
+
+	// when
+	let response = http_client::request(server.addr(), request_str);
+
+	// then
+	fetch.assert_no_more_requests();
+	response.assert_status("HTTP/1.1 200 OK");
+}
+
+#[test]
+fn should_not_request_content_twice() {
+	use std::thread;
+
+	// given
+	let (server, fetch, registrar) = serve_with_registrar_and_fetch_and_threads(true);
+	let gavcoin = GAVCOIN_ICON.from_hex().unwrap();
+	registrar.set_result(
+		"2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e".parse().unwrap(),
+		Ok(gavcoin.clone())
+	);
+	let request_str = "\
+		GET / HTTP/1.1\r\n\
+		Host: 2be00befcf008bc0e7d9cdefc194db9c75352e8632f48498b5a6bfce9f02c88e.parity\r\n\
+		Connection: close\r\n\
+		\r\n\
+	";
+	let fire_request = || {
+		let addr = server.addr().to_owned();
+		let req = request_str.to_owned();
+		thread::spawn(move || {
+			http_client::request(&addr, &req)
+		})
+	};
+	let control = fetch.manual();
+
+	// when
+
+	// Fire two requests at the same time
+	let r1 = fire_request();
+	let r2 = fire_request();
+
+	// wait for single request in fetch, the second one should go into waiting state.
+	control.wait_for_requests(1);
+	control.respond();
+
+	let response1 = r1.join().unwrap();
+	let response2 = r2.join().unwrap();
+
+	// then
+	fetch.assert_requested("https://raw.githubusercontent.com/ethcore/dapp-assets/b88e983abaa1a6a6345b8d9448c15b117ddb540e/tokens/gavcoin-64x64.png");
+	fetch.assert_no_more_requests();
+	response1.assert_status("HTTP/1.1 200 OK");
+	response2.assert_status("HTTP/1.1 200 OK");
+}
+
+#[test]
+fn should_stream_web_content() {
+	// given
+	let (server, fetch) = serve_with_fetch("token");
+
+	// when
+	let response = request(server,
+		"\
+			GET /web/token/https/parity.io/ HTTP/1.1\r\n\
+			Host: localhost:8080\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	response.assert_status("HTTP/1.1 200 OK");
+	assert_security_headers_for_embed(&response.headers);
+
+	fetch.assert_requested("https://parity.io/");
+	fetch.assert_no_more_requests();
+}
+
+#[test]
+fn should_return_error_on_invalid_token() {
+	// given
+	let (server, fetch) = serve_with_fetch("token");
+
+	// when
+	let response = request(server,
+		"\
+			GET /web/invalidtoken/https/parity.io/ HTTP/1.1\r\n\
+			Host: localhost:8080\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	response.assert_status("HTTP/1.1 400 Bad Request");
+	assert_security_headers_for_embed(&response.headers);
+
+	fetch.assert_no_more_requests();
+}
+
+#[test]
+fn should_return_error_on_invalid_protocol() {
+	// given
+	let (server, fetch) = serve_with_fetch("token");
+
+	// when
+	let response = request(server,
+		"\
+			GET /web/token/ftp/parity.io/ HTTP/1.1\r\n\
+			Host: localhost:8080\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	response.assert_status("HTTP/1.1 400 Bad Request");
+	assert_security_headers_for_embed(&response.headers);
+
+	fetch.assert_no_more_requests();
+}
+
+#[test]
+fn should_redirect_if_trailing_slash_is_missing() {
+	// given
+	let (server, fetch) = serve_with_fetch("token");
+
+	// when
+	let response = request(server,
+		"\
+			GET /web/token/https/parity.io HTTP/1.1\r\n\
+			Host: localhost:8080\r\n\
+			Connection: close\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	response.assert_status("HTTP/1.1 302 Found");
+	response.assert_header("Location", "/web/token/https/parity.io/");
+
+	fetch.assert_no_more_requests();
+}
+
+#[test]
+fn should_disallow_non_get_requests() {
+	// given
+	let (server, fetch) = serve_with_fetch("token");
+
+	// when
+	let response = request(server,
+		"\
+			POST /token/https/parity.io/ HTTP/1.1\r\n\
+			Host: web.parity\r\n\
+			Content-Type: application/json\r\n\
+			Connection: close\r\n\
+			\r\n\
+			123\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	response.assert_status("HTTP/1.1 405 Method Not Allowed");
+	assert_security_headers_for_embed(&response.headers);
+
+	fetch.assert_no_more_requests();
+}
+
+#[test]
+fn should_fix_absolute_requests_based_on_referer() {
+	// given
+	let (server, fetch) = serve_with_fetch("token");
+
+	// when
+	let response = request(server,
+		"\
+			GET /styles.css HTTP/1.1\r\n\
+			Host: localhost:8080\r\n\
+			Connection: close\r\n\
+			Referer: http://localhost:8080/web/token/https/parity.io/\r\n\
+			\r\n\
+		"
+	);
+
+	// then
+	response.assert_status("HTTP/1.1 302 Found");
+	response.assert_header("Location", "/web/token/https/parity.io/styles.css");
+
+	fetch.assert_no_more_requests();
+}

dapps/src/tests/helpers/fetch.rs

@@ -0,0 +1,122 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::{io, thread, time};
+use std::sync::{atomic, mpsc, Arc};
+use util::Mutex;
+
+use futures::{self, Future};
+use fetch::{self, Fetch};
+
+pub struct FetchControl {
+	sender: mpsc::Sender<()>,
+	fetch: FakeFetch,
+}
+
+impl FetchControl {
+	pub fn respond(self) {
+		self.sender.send(())
+			.expect("Fetch cannot be finished without sending a response at least once.");
+	}
+
+	pub fn wait_for_requests(&self, len: usize) {
+		const MAX_TIMEOUT_MS: u64 = 5000;
+		const ATTEMPTS: u64 = 10;
+		let mut attempts_left = ATTEMPTS;
+		loop {
+			let current = self.fetch.requested.lock().len();
+
+			if current == len {
+				break;
+			} else if attempts_left == 0 {
+				panic!(
+					"Timeout reached when waiting for pending requests. Expected: {}, current: {}",
+					len, current
+				);
+			} else {
+				attempts_left -= 1;
+				// Should we handle spurious timeouts better?
+				thread::park_timeout(time::Duration::from_millis(MAX_TIMEOUT_MS / ATTEMPTS));
+			}
+		}
+	}
+}
+
+#[derive(Clone, Default)]
+pub struct FakeFetch {
+	manual: Arc<Mutex<Option<mpsc::Receiver<()>>>>,
+	response: Arc<Mutex<Option<&'static [u8]>>>,
+	asserted: Arc<atomic::AtomicUsize>,
+	requested: Arc<Mutex<Vec<String>>>,
+}
+
+impl FakeFetch {
+	pub fn set_response(&self, data: &'static [u8]) {
+		*self.response.lock() = Some(data);
+	}
+
+	pub fn manual(&self) -> FetchControl {
+		assert!(self.manual.lock().is_none(), "Only one manual control may be active.");
+		let (tx, rx) = mpsc::channel();
+		*self.manual.lock() = Some(rx);
+
+		FetchControl {
+			sender: tx,
+			fetch: self.clone(),
+		}
+	}
+
+	pub fn assert_requested(&self, url: &str) {
+		let requests = self.requested.lock();
+		let idx = self.asserted.fetch_add(1, atomic::Ordering::SeqCst);
+
+		assert_eq!(requests.get(idx), Some(&url.to_owned()), "Expected fetch from specific URL.");
+	}
+
+	pub fn assert_no_more_requests(&self) {
+		let requests = self.requested.lock();
+		let len = self.asserted.load(atomic::Ordering::SeqCst);
+		assert_eq!(requests.len(), len, "Didn't expect any more requests, got: {:?}", &requests[len..]);
+	}
+}
+
+impl Fetch for FakeFetch {
+	type Result = futures::BoxFuture<fetch::Response, fetch::Error>;
+
+	fn new() -> Result<Self, fetch::Error> where Self: Sized {
+		Ok(FakeFetch::default())
+	}
+
+	fn fetch_with_abort(&self, url: &str, _abort: fetch::Abort) -> Self::Result {
+		self.requested.lock().push(url.into());
+		let manual = self.manual.clone();
+		let response = self.response.clone();
+
+		let (tx, rx) = futures::oneshot();
+		thread::spawn(move || {
+			if let Some(rx) = manual.lock().take() {
+				// wait for manual resume
+				let _ = rx.recv();
+			}
+
+			let data = response.lock().take().unwrap_or(b"Some content");
+			let cursor = io::Cursor::new(data);
+			tx.complete(fetch::Response::from_reader(cursor));
+		});
+
+		rx.map_err(|_| fetch::Error::Aborted).boxed()
+	}
+}

dapps/src/tests/helpers/mod.rs

@@ -17,50 +17,22 @@
 use std::env;
 use std::str;
 use std::sync::Arc;
-use rustc_serialize::hex::FromHex;
 use env_logger::LogBuilder;
 
 use ServerBuilder;
 use Server;
-use hash_fetch::urlhint::ContractClient;
+use fetch::Fetch;
-use util::{Bytes, Address, Mutex, ToPretty};
 use devtools::http_client;
 use parity_reactor::Remote;
 
-const REGISTRAR: &'static str = "8e4e9b13d4b45cb0befc93c3061b1408f67316b2";
+mod registrar;
-const URLHINT: &'static str = "deadbeefcafe0000000000000000000000000000";
+mod fetch;
+
+use self::registrar::FakeRegistrar;
+use self::fetch::FakeFetch;
+
 const SIGNER_PORT: u16 = 18180;
 
-pub struct FakeRegistrar {
-	pub calls: Arc<Mutex<Vec<(String, String)>>>,
-	pub responses: Mutex<Vec<Result<Bytes, String>>>,
-}
-
-impl FakeRegistrar {
-	fn new() -> Self {
-		FakeRegistrar {
-			calls: Arc::new(Mutex::new(Vec::new())),
-			responses: Mutex::new(
-				vec![
-					Ok(format!("000000000000000000000000{}", URLHINT).from_hex().unwrap()),
-					Ok(Vec::new())
-				]
-			),
-		}
-	}
-}
-
-impl ContractClient for FakeRegistrar {
-	fn registrar(&self) -> Result<Address, String> {
-		Ok(REGISTRAR.parse().unwrap())
-	}
-
-	fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String> {
-		self.calls.lock().push((address.to_hex(), data.to_hex()));
-		self.responses.lock().remove(0)
-	}
-}
-
 fn init_logger() {
 	// Initialize logger
 	if let Ok(log) = env::var("RUST_LOG") {
@@ -70,16 +42,21 @@ fn init_logger() {
 	}
 }
 
-pub fn init_server(hosts: Option<Vec<String>>, is_syncing: bool) -> (Server, Arc<FakeRegistrar>) {
+pub fn init_server<F, B>(hosts: Option<Vec<String>>, process: F, remote: Remote) -> (Server, Arc<FakeRegistrar>) where
+	F: FnOnce(ServerBuilder) -> ServerBuilder<B>,
+	B: Fetch,
+{
 	init_logger();
 	let registrar = Arc::new(FakeRegistrar::new());
 	let mut dapps_path = env::temp_dir();
 	dapps_path.push("non-existent-dir-to-prevent-fs-files-from-loading");
-	let mut builder = ServerBuilder::new(dapps_path.to_str().unwrap().into(), registrar.clone(), Remote::new_sync());
+	let server = process(ServerBuilder::new(
-	builder.with_sync_status(Arc::new(move || is_syncing));
+		dapps_path.to_str().unwrap().into(), registrar.clone(), remote,
-	builder.with_signer_address(Some(("127.0.0.1".into(), SIGNER_PORT)));
+	))
+		.signer_address(Some(("127.0.0.1".into(), SIGNER_PORT)))
+		.start_unsecured_http(&"127.0.0.1:0".parse().unwrap(), hosts).unwrap();
 	(
-		builder.start_unsecured_http(&"127.0.0.1:0".parse().unwrap(), hosts).unwrap(),
+		server,
 		registrar,
 	)
 }
@@ -89,25 +66,53 @@ pub fn serve_with_auth(user: &str, pass: &str) -> Server {
 	let registrar = Arc::new(FakeRegistrar::new());
 	let mut dapps_path = env::temp_dir();
 	dapps_path.push("non-existent-dir-to-prevent-fs-files-from-loading");
-	let mut builder = ServerBuilder::new(dapps_path.to_str().unwrap().into(), registrar.clone(), Remote::new_sync());
+	ServerBuilder::new(dapps_path.to_str().unwrap().into(), registrar.clone(), Remote::new_sync())
-	builder.with_signer_address(Some(("127.0.0.1".into(), SIGNER_PORT)));
+		.signer_address(Some(("127.0.0.1".into(), SIGNER_PORT)))
-	builder.start_basic_auth_http(&"127.0.0.1:0".parse().unwrap(), None, user, pass).unwrap()
+		.start_basic_auth_http(&"127.0.0.1:0".parse().unwrap(), None, user, pass).unwrap()
 }
 
 pub fn serve_hosts(hosts: Option<Vec<String>>) -> Server {
-	init_server(hosts, false).0
+	init_server(hosts, |builder| builder, Remote::new_sync()).0
 }
 
 pub fn serve_with_registrar() -> (Server, Arc<FakeRegistrar>) {
-	init_server(None, false)
+	init_server(None, |builder| builder, Remote::new_sync())
 }
 
 pub fn serve_with_registrar_and_sync() -> (Server, Arc<FakeRegistrar>) {
-	init_server(None, true)
+	init_server(None, |builder| {
+		builder.sync_status(Arc::new(|| true))
+	}, Remote::new_sync())
+}
+
+pub fn serve_with_registrar_and_fetch() -> (Server, FakeFetch, Arc<FakeRegistrar>) {
+	serve_with_registrar_and_fetch_and_threads(false)
+}
+
+pub fn serve_with_registrar_and_fetch_and_threads(multi_threaded: bool) -> (Server, FakeFetch, Arc<FakeRegistrar>) {
+	let fetch = FakeFetch::default();
+	let f = fetch.clone();
+	let (server, reg) = init_server(None, move |builder| {
+		builder.fetch(f.clone())
+	}, if multi_threaded { Remote::new_thread_per_future() } else { Remote::new_sync() });
+
+	(server, fetch, reg)
+}
+
+pub fn serve_with_fetch(web_token: &'static str) -> (Server, FakeFetch) {
+	let fetch = FakeFetch::default();
+	let f = fetch.clone();
+	let (server, _) = init_server(None, move |builder| {
+		builder
+			.fetch(f.clone())
+			.web_proxy_tokens(Arc::new(move |token| &token == web_token))
+	}, Remote::new_sync());
+
+	(server, fetch)
 }
 
 pub fn serve() -> Server {
-	init_server(None, false).0
+	init_server(None, |builder| builder, Remote::new_sync()).0
 }
 
 pub fn request(server: Server, request: &str) -> http_client::Response {

dapps/src/tests/helpers/registrar.rs

@@ -0,0 +1,72 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::str;
+use std::sync::Arc;
+use std::collections::HashMap;
+use rustc_serialize::hex::FromHex;
+
+use hash_fetch::urlhint::ContractClient;
+use util::{Bytes, Address, Mutex, H256, ToPretty};
+
+const REGISTRAR: &'static str = "8e4e9b13d4b45cb0befc93c3061b1408f67316b2";
+const URLHINT: &'static str = "deadbeefcafe0000000000000000000000000000";
+const URLHINT_RESOLVE: &'static str = "267b6922";
+const DEFAULT_HASH: &'static str = "1472a9e190620cdf6b31f383373e45efcfe869a820c91f9ccd7eb9fb45e4985d";
+
+pub struct FakeRegistrar {
+	pub calls: Arc<Mutex<Vec<(String, String)>>>,
+	pub responses: Mutex<HashMap<(String, String), Result<Bytes, String>>>,
+}
+
+impl FakeRegistrar {
+	pub fn new() -> Self {
+		FakeRegistrar {
+			calls: Arc::new(Mutex::new(Vec::new())),
+			responses: Mutex::new({
+				let mut map = HashMap::new();
+				map.insert(
+					(REGISTRAR.into(), "6795dbcd058740ee9a5a3fb9f1cfa10752baec87e09cc45cd7027fd54708271aca300c75000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000014100000000000000000000000000000000000000000000000000000000000000".into()),
+					Ok(format!("000000000000000000000000{}", URLHINT).from_hex().unwrap()),
+				);
+				map.insert(
+					(URLHINT.into(), format!("{}{}", URLHINT_RESOLVE, DEFAULT_HASH)),
+					Ok(vec![])
+				);
+				map
+			}),
+		}
+	}
+
+	pub fn set_result(&self, hash: H256, result: Result<Bytes, String>) {
+		self.responses.lock().insert(
+			(URLHINT.into(), format!("{}{:?}", URLHINT_RESOLVE, hash)),
+			result
+		);
+	}
+}
+
+impl ContractClient for FakeRegistrar {
+	fn registrar(&self) -> Result<Address, String> {
+		Ok(REGISTRAR.parse().unwrap())
+	}
+
+	fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String> {
+		let call = (address.to_hex(), data.to_hex());
+		self.calls.lock().push(call.clone());
+		self.responses.lock().get(&call).cloned().expect(&format!("No response for call: {:?}", call))
+	}
+}

dapps/src/url.rs

@@ -37,6 +37,9 @@ pub struct Url {
 	/// Empty entries of `""` correspond to trailing slashes.
 	pub path: Vec<String>,
 
+	/// The URL query.
+	pub query: Option<String>,
+
 	/// The URL username field, from the userinfo section of the URL.
 	///
 	/// `None` if the `@` character was not part of the input OR
@@ -82,15 +85,17 @@ impl Url {
 			_ => None,
 		};
 
-		let port = try!(raw_url.port_or_known_default().ok_or_else(|| format!("Unknown port for scheme: `{}`", raw_url.scheme())));
+		let port = raw_url.port_or_known_default().ok_or_else(|| format!("Unknown port for scheme: `{}`", raw_url.scheme()))?;
-		let host = try!(raw_url.host().ok_or_else(|| "Valid host, because only data:, mailto: protocols does not have host.".to_owned())).to_owned();
+		let host = raw_url.host().ok_or_else(|| "Valid host, because only data:, mailto: protocols does not have host.".to_owned())?.to_owned();
-		let path = try!(raw_url.path_segments().ok_or_else(|| "Valid path segments. In HTTP we won't get cannot-be-a-base URLs".to_owned()))
+		let path = raw_url.path_segments().ok_or_else(|| "Valid path segments. In HTTP we won't get cannot-be-a-base URLs".to_owned())?
 					.map(|part| part.to_owned()).collect();
+		let query = raw_url.query().map(|x| x.to_owned());
 
 		Ok(Url {
 			port: port,
 			host: host,
 			path: path,
+			query: query,
 			raw: raw_url,
 			username: username,
 			password: password,

dapps/src/web.rs

@@ -16,24 +16,36 @@
 
 //! Serving web-based content (proxying)
 
-use endpoint::{Endpoint, Handler, EndpointPath};
+use std::sync::Arc;
-use handlers::{ContentFetcherHandler, ContentHandler, ContentValidator, Redirection, extract_url};
-use page::{LocalPageEndpoint};
 use fetch::{self, Fetch};
-use url::Url;
+use parity_reactor::Remote;
+
 use hyper::{self, server, net, Next, Encoder, Decoder};
 use hyper::status::StatusCode;
-use parity_reactor::Remote;
+
-use apps::WEB_PATH;
+use apps;
+use endpoint::{Endpoint, Handler, EndpointPath};
+use handlers::{
+	ContentFetcherHandler, ContentHandler, ContentValidator, ValidatorResponse,
+	StreamingHandler, Redirection, extract_url,
+};
+use url::Url;
+use WebProxyTokens;
+
+pub type Embeddable = Option<(String, u16)>;
 
 pub struct Web<F> {
+	embeddable_on: Embeddable,
+	web_proxy_tokens: Arc<WebProxyTokens>,
 	remote: Remote,
 	fetch: F,
 }
 
 impl<F: Fetch> Web<F> {
-	pub fn boxed(remote: Remote, fetch: F) -> Box<Endpoint> {
+	pub fn boxed(embeddable_on: Embeddable, web_proxy_tokens: Arc<WebProxyTokens>, remote: Remote, fetch: F) -> Box<Endpoint> {
 		Box::new(Web {
+			embeddable_on: embeddable_on,
+			web_proxy_tokens: web_proxy_tokens,
 			remote: remote,
 			fetch: fetch,
 		})
@@ -48,20 +60,33 @@ impl<F: Fetch> Endpoint for Web<F> {
 			path: path,
 			remote: self.remote.clone(),
 			fetch: self.fetch.clone(),
+			web_proxy_tokens: self.web_proxy_tokens.clone(),
+			embeddable_on: self.embeddable_on.clone(),
 		})
 	}
 }
 
-pub struct WebInstaller;
+struct WebInstaller {
+	embeddable_on: Embeddable,
+}
 
 impl ContentValidator for WebInstaller {
 	type Error = String;
 
-	fn validate_and_install(&self, _response: fetch::Response) -> Result<LocalPageEndpoint, String> {
+	fn validate_and_install(&self, response: fetch::Response) -> Result<ValidatorResponse, String> {
-		// let path = unimplemented!();
+		let status = StatusCode::from_u16(response.status().to_u16());
-		// let mime = response.content_type().unwrap_or(mime!(Text/Html));
+		let is_html = response.is_html();
-		// Ok(LocalPageEndpoint::single_file(path, mime, PageCache::Enabled))
+		let mime = response.content_type().unwrap_or(mime!(Text/Html));
-		Err("unimplemented".into())
+		let mut handler = StreamingHandler::new(
+			response,
+			status,
+			mime,
+			self.embeddable_on.clone(),
+		);
+		if is_html {
+			handler.set_initial_content(&format!(r#"<script src="/{}/inject.js"></script>"#, apps::UTILS_PATH));
+		}
+		Ok(ValidatorResponse::Streaming(handler))
 	}
 }
 
@@ -78,46 +103,61 @@ struct WebHandler<F: Fetch> {
 	path: EndpointPath,
 	remote: Remote,
 	fetch: F,
+	web_proxy_tokens: Arc<WebProxyTokens>,
+	embeddable_on: Embeddable,
 }
 
 impl<F: Fetch> WebHandler<F> {
-	fn extract_target_url(url: Option<Url>) -> Result<String, State<F>> {
+	fn extract_target_url(&self, url: Option<Url>) -> Result<String, State<F>> {
-		let path = match url {
+		let (path, query) = match url {
-			Some(url) => url.path,
+			Some(url) => (url.path, url.query),
 			None => {
-				return Err(State::Error(
+				return Err(State::Error(ContentHandler::error(
-					ContentHandler::error(StatusCode::BadRequest, "Invalid URL", "Couldn't parse URL", None, None)
+					StatusCode::BadRequest, "Invalid URL", "Couldn't parse URL", None, self.embeddable_on.clone()
-				));
+				)));
 			}
 		};
 
-		// TODO [ToDr] Check if token supplied in URL is correct.
-
 		// Support domain based routing.
 		let idx = match path.get(0).map(|m| m.as_ref()) {
-			Some(WEB_PATH) => 1,
+			Some(apps::WEB_PATH) => 1,
 			_ => 0,
 		};
 
+		// Check if token supplied in URL is correct.
+		match path.get(idx) {
+			Some(ref token) if self.web_proxy_tokens.is_web_proxy_token_valid(token) => {},
+			_ => {
+				return Err(State::Error(ContentHandler::error(
+					StatusCode::BadRequest, "Invalid Access Token", "Invalid or old web proxy access token supplied.", Some("Try refreshing the page."), self.embeddable_on.clone()
+				)));
+			}
+		}
+
 		// Validate protocol
-		let protocol = match path.get(idx).map(|a| a.as_str()) {
+		let protocol = match path.get(idx + 1).map(|a| a.as_str()) {
 			Some("http") => "http",
 			Some("https") => "https",
 			_ => {
-				return Err(State::Error(
+				return Err(State::Error(ContentHandler::error(
-					ContentHandler::error(StatusCode::BadRequest, "Invalid Protocol", "Invalid protocol used", None, None)
+					StatusCode::BadRequest, "Invalid Protocol", "Invalid protocol used.", None, self.embeddable_on.clone()
-				));
+				)));
 			}
 		};
 
 		// Redirect if address to main page does not end with /
-		if let None = path.get(idx + 2) {
+		if let None = path.get(idx + 3) {
 			return Err(State::Redirecting(
 				Redirection::new(&format!("/{}/", path.join("/")))
 			));
 		}
 
-		Ok(format!("{}://{}", protocol, path[2..].join("/")))
+		let query = match query {
+			Some(query) => format!("?{}", query),
+			None => "".into(),
+		};
+
+		Ok(format!("{}://{}{}", protocol, path[idx + 2..].join("/"), query))
 	}
 }
 
@@ -126,7 +166,7 @@ impl<F: Fetch> server::Handler<net::HttpStream> for WebHandler<F> {
 		let url = extract_url(&request);
 
 		// First extract the URL (reject invalid URLs)
-		let target_url = match Self::extract_target_url(url) {
+		let target_url = match self.extract_target_url(url) {
 			Ok(url) => url,
 			Err(error) => {
 				self.state = error;
@@ -134,12 +174,14 @@ impl<F: Fetch> server::Handler<net::HttpStream> for WebHandler<F> {
 			}
 		};
 
-		let (mut handler, _control) = ContentFetcherHandler::new(
+		let mut handler = ContentFetcherHandler::new(
 			target_url,
 			self.path.clone(),
 			self.control.clone(),
-			WebInstaller,
+			WebInstaller {
-			None,
+				embeddable_on: self.embeddable_on.clone(),
+			},
+			self.embeddable_on.clone(),
 			self.remote.clone(),
 			self.fetch.clone(),
 		);

db/src/database.rs

@@ -73,10 +73,10 @@ impl WriteCache {
 
 				match *cache_entry {
 					WriteCacheEntry::Write(ref val) => {
-						try!(batch.put(&key, val));
+						batch.put(&key, val)?;
 					},
 					WriteCacheEntry::Remove => {
-						try!(batch.delete(&key));
+						batch.delete(&key)?;
 					},
 				}
 				key.clone()
@@ -87,14 +87,14 @@ impl WriteCache {
 			removed_so_far = removed_so_far + 1;
 		}
 		if removed_so_far > 0 {
-			try!(db.write(batch));
+			db.write(batch)?;
 		}
 		Ok(())
 	}
 
 	/// flushes until cache is empty
 	fn flush_all(&mut self, db: &DB) -> Result<(), Error> {
-		while !self.is_empty() { try!(self.flush(db, FLUSH_BATCH_SIZE)); }
+		while !self.is_empty() { self.flush(db, FLUSH_BATCH_SIZE)?; }
 		Ok(())
 	}
 
@@ -104,7 +104,7 @@ impl WriteCache {
 
 	fn try_shrink(&mut self, db: &DB) -> Result<(), Error> {
 		if self.entries.len() > self.preferred_len {
-			try!(self.flush(db, FLUSH_BATCH_SIZE));
+			self.flush(db, FLUSH_BATCH_SIZE)?;
 		}
 		Ok(())
 	}
@@ -135,7 +135,7 @@ impl Database {
 		if db_lock.is_none() { return Ok(()); }
 		let db = db_lock.as_ref().unwrap();
 
-		try!(cache_lock.try_shrink(&db));
+		cache_lock.try_shrink(&db)?;
 		Ok(())
 	}
 
@@ -145,7 +145,7 @@ impl Database {
 		if db_lock.is_none() { return Ok(()); }
 		let db = db_lock.as_ref().expect("we should have exited with Ok(()) on the previous step");
 
-		try!(cache_lock.flush_all(&db));
+		cache_lock.flush_all(&db)?;
 		Ok(())
 
 	}
@@ -174,7 +174,7 @@ impl DatabaseService for Database {
 			opts.set_block_based_table_factory(&block_opts);
 			opts.set_prefix_extractor_fixed_size(size);
 		}
-		*db = Some(try!(DB::open(&opts, &path)));
+		*db = Some(DB::open(&opts, &path)?);
 
 		Ok(())
 	}
@@ -185,7 +185,7 @@ impl DatabaseService for Database {
 	}
 
 	fn close(&self) -> Result<(), Error> {
-		try!(self.flush_all());
+		self.flush_all()?;
 
 		let mut db = self.db.write();
 		if db.is_none() { return Err(Error::IsClosed); }
@@ -231,9 +231,9 @@ impl DatabaseService for Database {
 			}
 		}
 		let db_lock = self.db.read();
-		let db = try!(db_lock.as_ref().ok_or(Error::IsClosed));
+		let db = db_lock.as_ref().ok_or(Error::IsClosed)?;
 
-		match try!(db.get(key)) {
+		match db.get(key)? {
 			Some(db_vec) => {
 				Ok(Some(db_vec.to_vec()))
 			},
@@ -243,7 +243,7 @@ impl DatabaseService for Database {
 
 	fn get_by_prefix(&self, prefix: &[u8]) -> Result<Option<Vec<u8>>, Error> {
 		let db_lock = self.db.read();
-		let db = try!(db_lock.as_ref().ok_or(Error::IsClosed));
+		let db = db_lock.as_ref().ok_or(Error::IsClosed)?;
 
 		let mut iter = db.iterator(IteratorMode::From(prefix, Direction::Forward));
 		match iter.next() {
@@ -255,14 +255,14 @@ impl DatabaseService for Database {
 
 	fn is_empty(&self) -> Result<bool, Error> {
 		let db_lock = self.db.read();
-		let db = try!(db_lock.as_ref().ok_or(Error::IsClosed));
+		let db = db_lock.as_ref().ok_or(Error::IsClosed)?;
 
 		Ok(db.iterator(IteratorMode::Start).next().is_none())
 	}
 
 	fn iter(&self) -> Result<IteratorHandle, Error> {
 		let db_lock = self.db.read();
-		let db = try!(db_lock.as_ref().ok_or(Error::IsClosed));
+		let db = db_lock.as_ref().ok_or(Error::IsClosed)?;
 
 		let mut iterators = self.iterators.write();
 		let next_iterator = iterators.keys().last().unwrap_or(&0) + 1;

db/src/lib.rs.in

@@ -52,27 +52,27 @@ impl std::convert::From<nanoipc::SocketError> for ServiceError {
 
 pub fn blocks_service_url(db_path: &str) -> Result<String, std::io::Error> {
 	let mut path = PathBuf::from(db_path);
-	try!(::std::fs::create_dir_all(db_path));
+	::std::fs::create_dir_all(db_path)?;
 	path.push("blocks.ipc");
 	Ok(format!("ipc://{}", path.to_str().unwrap()))
 }
 
 pub fn extras_service_url(db_path: &str) -> Result<String, ::std::io::Error> {
 	let mut path = PathBuf::from(db_path);
-	try!(::std::fs::create_dir_all(db_path));
+	::std::fs::create_dir_all(db_path)?;
 	path.push("extras.ipc");
 	Ok(format!("ipc://{}", path.to_str().unwrap()))
 }
 
 pub fn blocks_client(db_path: &str) -> Result<DatabaseConnection, ServiceError> {
-	let url = try!(blocks_service_url(db_path));
+	let url = blocks_service_url(db_path)?;
-	let client = try!(nanoipc::generic_client::<DatabaseClient<_>>(&url));
+	let client = nanoipc::generic_client::<DatabaseClient<_>>(&url)?;
 	Ok(client)
 }
 
 pub fn extras_client(db_path: &str) -> Result<DatabaseConnection, ServiceError> {
-	let url = try!(extras_service_url(db_path));
+	let url = extras_service_url(db_path)?;
-	let client = try!(nanoipc::generic_client::<DatabaseClient<_>>(&url));
+	let client = nanoipc::generic_client::<DatabaseClient<_>>(&url)?;
 	Ok(client)
 }
 

devtools/src/http_client.rs

@@ -27,6 +27,21 @@ pub struct Response {
 	pub body: String,
 }
 
+impl Response {
+	pub fn assert_header(&self, header: &str, value: &str) {
+		let header = format!("{}: {}", header, value);
+		assert!(self.headers.iter().find(|h| *h == &header).is_some(), "Couldn't find header {} in {:?}", header, &self.headers)
+	}
+
+	pub fn assert_status(&self, status: &str) {
+		assert_eq!(self.status, status.to_owned(), "Got unexpected code. Body: {:?}", self.body);
+	}
+
+	pub fn assert_security_headers_present(&self, port: Option<u16>) {
+		assert_security_headers_present(&self.headers, port)
+	}
+}
+
 pub fn read_block(lines: &mut Lines, all: bool) -> String {
 	let mut block = String::new();
 	loop {
@@ -65,7 +80,7 @@ fn connect(address: &SocketAddr) -> TcpStream {
 
 pub fn request(address: &SocketAddr, request: &str) -> Response {
 	let mut req = connect(address);
-	req.set_read_timeout(Some(Duration::from_secs(1))).unwrap();
+	req.set_read_timeout(Some(Duration::from_secs(2))).unwrap();
 	req.write_all(request.as_bytes()).unwrap();
 
 	let mut response = String::new();

ethash/src/compute.rs

@@ -116,17 +116,17 @@ impl Light {
 	pub fn from_file(block_number: u64) -> io::Result<Light> {
 		let seed_compute = SeedHashCompute::new();
 		let path = Light::file_path(seed_compute.get_seedhash(block_number));
-		let mut file = try!(File::open(path));
+		let mut file = File::open(path)?;
 
 		let cache_size = get_cache_size(block_number);
-		if try!(file.metadata()).len() != cache_size as u64 {
+		if file.metadata()?.len() != cache_size as u64 {
 			return Err(io::Error::new(io::ErrorKind::Other, "Cache file size mismatch"));
 		}
 		let num_nodes = cache_size / NODE_BYTES;
 		let mut nodes: Vec<Node> = Vec::new();
 		nodes.resize(num_nodes, unsafe { mem::uninitialized() });
 		let buf = unsafe { slice::from_raw_parts_mut(nodes.as_mut_ptr() as *mut u8, cache_size) };
-		try!(file.read_exact(buf));
+		file.read_exact(buf)?;
 		Ok(Light {
 			cache: nodes,
 			block_number: block_number,
@@ -144,16 +144,16 @@ impl Light {
 
 			if deprecated.exists() {
 				debug!(target: "ethash", "removing: {:?}", &deprecated);
-				try!(fs::remove_file(deprecated));
+				fs::remove_file(deprecated)?;
 			}
 		}
 
-		try!(fs::create_dir_all(path.parent().unwrap()));
+		fs::create_dir_all(path.parent().unwrap())?;
-		let mut file = try!(File::create(&path));
+		let mut file = File::create(&path)?;
 
 		let cache_size = self.cache.len() * NODE_BYTES;
 		let buf = unsafe { slice::from_raw_parts(self.cache.as_ptr() as *const u8, cache_size) };
-		try!(file.write(buf));
+		file.write(buf)?;
 		Ok(path)
 	}
 }

ethcore/light/src/client/mod.rs

@@ -26,6 +26,7 @@ use ethcore::transaction::PendingTransaction;
 use ethcore::blockchain_info::BlockChainInfo;
 use ethcore::spec::Spec;
 use ethcore::service::ClientIoMessage;
+use ethcore::encoded;
 use io::IoChannel;
 
 use util::hash::{H256, H256FastMap};
@@ -233,11 +234,11 @@ impl Provider for Client {
 		None
 	}
 
-	fn block_header(&self, id: BlockId) -> Option<Bytes> {
+	fn block_header(&self, id: BlockId) -> Option<encoded::Header> {
-		self.chain.get_header(id)
+		self.chain.get_header(id).map(encoded::Header::new)
 	}
 
-	fn block_body(&self, _id: BlockId) -> Option<Bytes> {
+	fn block_body(&self, _id: BlockId) -> Option<encoded::Body> {
 		None
 	}
 
@@ -253,7 +254,7 @@ impl Provider for Client {
 		Vec::new()
 	}
 
-	fn header_proof(&self, _req: request::HeaderProof) -> Option<(Bytes, Vec<Bytes>)> {
+	fn header_proof(&self, _req: request::HeaderProof) -> Option<(encoded::Header, Vec<Bytes>)> {
 		None
 	}
 

ethcore/light/src/net/buffer_flow.rs

@@ -135,10 +135,10 @@ impl RlpDecodable for CostTable {
 		let mut header_proofs = None;
 
 		for row in rlp.iter() {
-			let msg_id: u8 = try!(row.val_at(0));
+			let msg_id: u8 = row.val_at(0)?;
 			let cost = {
-				let base = try!(row.val_at(1));
+				let base = row.val_at(1)?;
-				let per = try!(row.val_at(2));
+				let per = row.val_at(2)?;
 
 				Cost(base, per)
 			};
@@ -155,12 +155,12 @@ impl RlpDecodable for CostTable {
 		}
 
 		Ok(CostTable {
-			headers: try!(headers.ok_or(DecoderError::Custom("No headers cost specified"))),
+			headers: headers.ok_or(DecoderError::Custom("No headers cost specified"))?,
-			bodies: try!(bodies.ok_or(DecoderError::Custom("No bodies cost specified"))),
+			bodies: bodies.ok_or(DecoderError::Custom("No bodies cost specified"))?,
-			receipts: try!(receipts.ok_or(DecoderError::Custom("No receipts cost specified"))),
+			receipts: receipts.ok_or(DecoderError::Custom("No receipts cost specified"))?,
-			state_proofs: try!(state_proofs.ok_or(DecoderError::Custom("No proofs cost specified"))),
+			state_proofs: state_proofs.ok_or(DecoderError::Custom("No proofs cost specified"))?,
-			contract_codes: try!(contract_codes.ok_or(DecoderError::Custom("No contract codes specified"))),
+			contract_codes: contract_codes.ok_or(DecoderError::Custom("No contract codes specified"))?,
-			header_proofs: try!(header_proofs.ok_or(DecoderError::Custom("No header proofs cost specified"))),
+			header_proofs: header_proofs.ok_or(DecoderError::Custom("No header proofs cost specified"))?,
 		})
 	}
 }

ethcore/light/src/net/mod.rs

@@ -155,7 +155,7 @@ impl Peer {
 		flow_params.recharge(&mut self.local_buffer);
 
 		let max_cost = flow_params.compute_cost(kind, max);
-		try!(self.local_buffer.deduct_cost(max_cost));
+		self.local_buffer.deduct_cost(max_cost)?;
 		Ok(max_cost)
 	}
 
@@ -298,7 +298,7 @@ impl LightProtocol {
 	/// with an event.
 	pub fn request_from(&self, io: &IoContext, peer_id: &PeerId, request: Request) -> Result<ReqId, Error> {
 		let peers = self.peers.read();
-		let peer = try!(peers.get(peer_id).ok_or_else(|| Error::UnknownPeer));
+		let peer = peers.get(peer_id).ok_or_else(|| Error::UnknownPeer)?;
 		let mut peer = peer.lock();
 
 		if !peer.idle { return Err(Error::Overburdened) }
@@ -307,7 +307,7 @@ impl LightProtocol {
 			Some((ref mut buf, ref flow)) => {
 				flow.recharge(buf);
 				let max = flow.compute_cost(request.kind(), request.amount());
-				try!(buf.deduct_cost(max));
+				buf.deduct_cost(max)?;
 			}
 			None => return Err(Error::NotServer),
 		}
@@ -414,8 +414,8 @@ impl LightProtocol {
 	//   - check whether request was made
 	//   - check whether request kinds match
 	fn pre_verify_response(&self, peer: &PeerId, kind: request::Kind, raw: &UntrustedRlp) -> Result<ReqId, Error> {
-		let req_id: usize = try!(raw.val_at(0));
+		let req_id: usize = raw.val_at(0)?;
-		let cur_buffer: U256 = try!(raw.val_at(1));
+		let cur_buffer: U256 = raw.val_at(1)?;
 
 		trace!(target: "les", "pre-verifying response from peer {}, kind={:?}", peer, kind);
 
@@ -621,7 +621,7 @@ impl LightProtocol {
 			}
 		};
 
-		let (status, capabilities, flow_params) = try!(status::parse_handshake(data));
+		let (status, capabilities, flow_params) = status::parse_handshake(data)?;
 
 		trace!(target: "les", "Connected peer with chain head {:?}", (status.head_hash, status.head_num));
 
@@ -663,7 +663,7 @@ impl LightProtocol {
 			return Ok(())
 		}
 
-		let announcement = try!(status::parse_announcement(data));
+		let announcement = status::parse_announcement(data)?;
 
 		// scope to ensure locks are dropped before moving into handler-space.
 		{
@@ -716,25 +716,25 @@ impl LightProtocol {
 
 		let mut peer = peer.lock();
 
-		let req_id: u64 = try!(data.val_at(0));
+		let req_id: u64 = data.val_at(0)?;
-		let data = try!(data.at(1));
+		let data = data.at(1)?;
 
 		let start_block = {
-			if try!(data.at(0)).size() == 32 {
+			if data.at(0)?.size() == 32 {
-				HashOrNumber::Hash(try!(data.val_at(0)))
+				HashOrNumber::Hash(data.val_at(0)?)
 			} else {
-				HashOrNumber::Number(try!(data.val_at(0)))
+				HashOrNumber::Number(data.val_at(0)?)
 			}
 		};
 
 		let req = request::Headers {
 			start: start_block,
-			max: ::std::cmp::min(MAX_HEADERS, try!(data.val_at(1))),
+			max: ::std::cmp::min(MAX_HEADERS, data.val_at(1)?),
-			skip: try!(data.val_at(2)),
+			skip: data.val_at(2)?,
-			reverse: try!(data.val_at(3)),
+			reverse: data.val_at(3)?,
 		};
 
-		let max_cost = try!(peer.deduct_max(&self.flow_params, request::Kind::Headers, req.max));
+		let max_cost = peer.deduct_max(&self.flow_params, request::Kind::Headers, req.max)?;
 
 		let response = self.provider.block_headers(req);
 		let actual_cost = self.flow_params.compute_cost(request::Kind::Headers, response.len());
@@ -746,7 +746,7 @@ impl LightProtocol {
 			stream.append(&req_id).append(&cur_buffer).begin_list(response.len());
 
 			for header in response {
-				stream.append_raw(&header, 1);
+				stream.append_raw(&header.into_inner(), 1);
 			}
 
 			stream.out()
@@ -757,8 +757,8 @@ impl LightProtocol {
 
 	// Receive a response for block headers.
 	fn block_headers(&self, peer: &PeerId, io: &IoContext, raw: UntrustedRlp) -> Result<(), Error> {
-		let req_id = try!(self.pre_verify_response(peer, request::Kind::Headers, &raw));
+		let req_id = self.pre_verify_response(peer, request::Kind::Headers, &raw)?;
-		let raw_headers: Vec<_> = try!(raw.at(2)).iter().map(|x| x.as_raw().to_owned()).collect();
+		let raw_headers: Vec<_> = raw.at(2)?.iter().map(|x| x.as_raw().to_owned()).collect();
 
 		for handler in &self.handlers {
 			handler.on_block_headers(&Ctx {
@@ -785,16 +785,19 @@ impl LightProtocol {
 		};
 		let mut peer = peer.lock();
 
-		let req_id: u64 = try!(data.val_at(0));
+		let req_id: u64 = data.val_at(0)?;
 
 		let req = request::Bodies {
-			block_hashes: try!(try!(data.at(1)).iter().take(MAX_BODIES).map(|x| x.as_val()).collect())
+			block_hashes: data.at(1)?.iter()
+				.take(MAX_BODIES)
+				.map(|x| x.as_val())
+				.collect::<Result<_, _>>()?
 		};
 
-		let max_cost = try!(peer.deduct_max(&self.flow_params, request::Kind::Bodies, req.block_hashes.len()));
+		let max_cost = peer.deduct_max(&self.flow_params, request::Kind::Bodies, req.block_hashes.len())?;
 
 		let response = self.provider.block_bodies(req);
-		let response_len = response.iter().filter(|x| &x[..] != &::rlp::EMPTY_LIST_RLP).count();
+		let response_len = response.iter().filter(|x| x.is_some()).count();
 		let actual_cost = self.flow_params.compute_cost(request::Kind::Bodies, response_len);
 		assert!(max_cost >= actual_cost, "Actual cost exceeded maximum computed cost.");
 
@@ -805,7 +808,10 @@ impl LightProtocol {
 			stream.append(&req_id).append(&cur_buffer).begin_list(response.len());
 
 			for body in response {
-				stream.append_raw(&body, 1);
+				match body {
+					Some(body) => stream.append_raw(&body.into_inner(), 1),
+					None => stream.append_empty_data(),
+				};
 			}
 
 			stream.out()
@@ -816,8 +822,8 @@ impl LightProtocol {
 
 	// Receive a response for block bodies.
 	fn block_bodies(&self, peer: &PeerId, io: &IoContext, raw: UntrustedRlp) -> Result<(), Error> {
-		let req_id = try!(self.pre_verify_response(peer, request::Kind::Bodies, &raw));
+		let req_id = self.pre_verify_response(peer, request::Kind::Bodies, &raw)?;
-		let raw_bodies: Vec<Bytes> = try!(raw.at(2)).iter().map(|x| x.as_raw().to_owned()).collect();
+		let raw_bodies: Vec<Bytes> = raw.at(2)?.iter().map(|x| x.as_raw().to_owned()).collect();
 
 		for handler in &self.handlers {
 			handler.on_block_bodies(&Ctx {
@@ -844,13 +850,16 @@ impl LightProtocol {
 		};
 		let mut peer = peer.lock();
 
-		let req_id: u64 = try!(data.val_at(0));
+		let req_id: u64 = data.val_at(0)?;
 
 		let req = request::Receipts {
-			block_hashes: try!(try!(data.at(1)).iter().take(MAX_RECEIPTS).map(|x| x.as_val()).collect())
+			block_hashes: data.at(1)?.iter()
+				.take(MAX_RECEIPTS)
+				.map(|x| x.as_val())
+				.collect::<Result<_,_>>()?
 		};
 
-		let max_cost = try!(peer.deduct_max(&self.flow_params, request::Kind::Receipts, req.block_hashes.len()));
+		let max_cost = peer.deduct_max(&self.flow_params, request::Kind::Receipts, req.block_hashes.len())?;
 
 		let response = self.provider.receipts(req);
 		let response_len = response.iter().filter(|x| &x[..] != &::rlp::EMPTY_LIST_RLP).count();
@@ -875,11 +884,11 @@ impl LightProtocol {
 
 	// Receive a response for receipts.
 	fn receipts(&self, peer: &PeerId, io: &IoContext, raw: UntrustedRlp) -> Result<(), Error> {
-		let req_id = try!(self.pre_verify_response(peer, request::Kind::Receipts, &raw));
+		let req_id = self.pre_verify_response(peer, request::Kind::Receipts, &raw)?;
-		let raw_receipts: Vec<Vec<Receipt>> = try!(try!(raw.at(2))
+		let raw_receipts: Vec<Vec<Receipt>> = raw.at(2)?
 			.iter()
 			.map(|x| x.as_val())
-			.collect());
+			.collect::<Result<_,_>>()?;
 
 		for handler in &self.handlers {
 			handler.on_receipts(&Ctx {
@@ -906,24 +915,24 @@ impl LightProtocol {
 		};
 		let mut peer = peer.lock();
 
-		let req_id: u64 = try!(data.val_at(0));
+		let req_id: u64 = data.val_at(0)?;
 
 		let req = {
-			let requests: Result<Vec<_>, Error> = try!(data.at(1)).iter().take(MAX_PROOFS).map(|x| {
+			let requests: Result<Vec<_>, Error> = data.at(1)?.iter().take(MAX_PROOFS).map(|x| {
 				Ok(request::StateProof {
-					block: try!(x.val_at(0)),
+					block: x.val_at(0)?,
-					key1: try!(x.val_at(1)),
+					key1: x.val_at(1)?,
-					key2: if try!(x.at(2)).is_empty() { None } else { Some(try!(x.val_at(2))) },
+					key2: if x.at(2)?.is_empty() { None } else { Some(x.val_at(2)?) },
-					from_level: try!(x.val_at(3)),
+					from_level: x.val_at(3)?,
 				})
 			}).collect();
 
 			request::StateProofs {
-				requests: try!(requests),
+				requests: requests?,
 			}
 		};
 
-		let max_cost = try!(peer.deduct_max(&self.flow_params, request::Kind::StateProofs, req.requests.len()));
+		let max_cost = peer.deduct_max(&self.flow_params, request::Kind::StateProofs, req.requests.len())?;
 
 		let response = self.provider.proofs(req);
 		let response_len = response.iter().filter(|x| &x[..] != &::rlp::EMPTY_LIST_RLP).count();
@@ -948,9 +957,9 @@ impl LightProtocol {
 
 	// Receive a response for proofs.
 	fn proofs(&self, peer: &PeerId, io: &IoContext, raw: UntrustedRlp) -> Result<(), Error> {
-		let req_id = try!(self.pre_verify_response(peer, request::Kind::StateProofs, &raw));
+		let req_id = self.pre_verify_response(peer, request::Kind::StateProofs, &raw)?;
 
-		let raw_proofs: Vec<Vec<Bytes>> = try!(raw.at(2)).iter()
+		let raw_proofs: Vec<Vec<Bytes>> = raw.at(2)?.iter()
 			.map(|x| x.iter().map(|node| node.as_raw().to_owned()).collect())
 			.collect();
 
@@ -979,22 +988,22 @@ impl LightProtocol {
 		};
 		let mut peer = peer.lock();
 
-		let req_id: u64 = try!(data.val_at(0));
+		let req_id: u64 = data.val_at(0)?;
 
 		let req = {
-			let requests: Result<Vec<_>, Error> = try!(data.at(1)).iter().take(MAX_CODES).map(|x| {
+			let requests: Result<Vec<_>, Error> = data.at(1)?.iter().take(MAX_CODES).map(|x| {
 				Ok(request::ContractCode {
-					block_hash: try!(x.val_at(0)),
+					block_hash: x.val_at(0)?,
-					account_key: try!(x.val_at(1)),
+					account_key: x.val_at(1)?,
 				})
 			}).collect();
 
 			request::ContractCodes {
-				code_requests: try!(requests),
+				code_requests: requests?,
 			}
 		};
 
-		let max_cost = try!(peer.deduct_max(&self.flow_params, request::Kind::Codes, req.code_requests.len()));
+		let max_cost = peer.deduct_max(&self.flow_params, request::Kind::Codes, req.code_requests.len())?;
 
 		let response = self.provider.contract_codes(req);
 		let response_len = response.iter().filter(|x| !x.is_empty()).count();
@@ -1019,9 +1028,11 @@ impl LightProtocol {
 
 	// Receive a response for contract code.
 	fn contract_code(&self, peer: &PeerId, io: &IoContext, raw: UntrustedRlp) -> Result<(), Error> {
-		let req_id = try!(self.pre_verify_response(peer, request::Kind::Codes, &raw));
+		let req_id = self.pre_verify_response(peer, request::Kind::Codes, &raw)?;
 
-		let raw_code: Vec<Bytes> = try!(try!(raw.at(2)).iter().map(|x| x.as_val()).collect());
+		let raw_code: Vec<Bytes> = raw.at(2)?.iter()
+			.map(|x| x.as_val())
+			.collect::<Result<_,_>>()?;
 
 		for handler in &self.handlers {
 			handler.on_code(&Ctx {
@@ -1048,23 +1059,23 @@ impl LightProtocol {
 		};
 		let mut peer = peer.lock();
 
-		let req_id: u64 = try!(data.val_at(0));
+		let req_id: u64 = data.val_at(0)?;
 
 		let req = {
-			let requests: Result<Vec<_>, Error> = try!(data.at(1)).iter().take(MAX_PROOFS).map(|x| {
+			let requests: Result<Vec<_>, Error> = data.at(1)?.iter().take(MAX_PROOFS).map(|x| {
 				Ok(request::HeaderProof {
-					cht_number: try!(x.val_at(0)),
+					cht_number: x.val_at(0)?,
-					block_number: try!(x.val_at(1)),
+					block_number: x.val_at(1)?,
-					from_level: try!(x.val_at(2)),
+					from_level: x.val_at(2)?,
 				})
 			}).collect();
 
 			request::HeaderProofs {
-				requests: try!(requests),
+				requests: requests?,
 			}
 		};
 
-		let max_cost = try!(peer.deduct_max(&self.flow_params, request::Kind::HeaderProofs, req.requests.len()));
+		let max_cost = peer.deduct_max(&self.flow_params, request::Kind::HeaderProofs, req.requests.len())?;
 
 		let response = self.provider.header_proofs(req);
 		let response_len = response.iter().filter(|x| &x[..] != ::rlp::EMPTY_LIST_RLP).count();
@@ -1091,13 +1102,15 @@ impl LightProtocol {
 	fn header_proofs(&self, peer: &PeerId, io: &IoContext, raw: UntrustedRlp) -> Result<(), Error> {
 		fn decode_res(raw: UntrustedRlp) -> Result<(Bytes, Vec<Bytes>), ::rlp::DecoderError> {
 			Ok((
-				try!(raw.val_at(0)),
+				raw.val_at(0)?,
-				try!(raw.at(1)).iter().map(|x| x.as_raw().to_owned()).collect(),
+				raw.at(1)?.iter().map(|x| x.as_raw().to_owned()).collect(),
 			))
 		}
 
-		let req_id = try!(self.pre_verify_response(peer, request::Kind::HeaderProofs, &raw));
+		let req_id = self.pre_verify_response(peer, request::Kind::HeaderProofs, &raw)?;
-		let raw_proofs: Vec<_> = try!(try!(raw.at(2)).iter().map(decode_res).collect());
+		let raw_proofs: Vec<_> = raw.at(2)?.iter()
+			.map(decode_res)
+			.collect::<Result<_,_>>()?;
 
 		for handler in &self.handlers {
 			handler.on_header_proofs(&Ctx {
@@ -1114,7 +1127,10 @@ impl LightProtocol {
 	fn relay_transactions(&self, peer: &PeerId, io: &IoContext, data: UntrustedRlp) -> Result<(), Error> {
 		const MAX_TRANSACTIONS: usize = 256;
 
-		let txs: Vec<_> = try!(data.iter().take(MAX_TRANSACTIONS).map(|x| x.as_val::<SignedTransaction>()).collect());
+		let txs: Vec<_> = data.iter()
+			.take(MAX_TRANSACTIONS)
+			.map(|x| x.as_val::<SignedTransaction>())
+			.collect::<Result<_,_>>()?;
 
 		debug!(target: "les", "Received {} transactions to relay from peer {}", txs.len(), peer);
 

ethcore/light/src/net/status.rs

@@ -100,7 +100,7 @@ impl<'a> Parser<'a> {
 	fn expect_raw(&mut self, key: Key) -> Result<UntrustedRlp<'a>, DecoderError> {
 		trace!(target: "les", "Expecting key {}", key.as_str());
 		let pre_pos = self.pos;
-		if let Some((k, val)) = try!(self.get_next()) {
+		if let Some((k, val)) = self.get_next()? {
 			if k == key { return Ok(val) }
 		}
 
@@ -111,12 +111,12 @@ impl<'a> Parser<'a> {
 	// get the next key and value RLP.
 	fn get_next(&mut self) -> Result<Option<(Key, UntrustedRlp<'a>)>, DecoderError> {
 		while self.pos < self.rlp.item_count() {
-			let pair = try!(self.rlp.at(self.pos));
+			let pair = self.rlp.at(self.pos)?;
-			let k: String = try!(pair.val_at(0));
+			let k: String = pair.val_at(0)?;
 
 			self.pos += 1;
 			match Key::from_str(&k) {
-				Some(key) => return Ok(Some((key , try!(pair.at(1))))),
+				Some(key) => return Ok(Some((key , pair.at(1)?))),
 				None => continue,
 			}
 		}
@@ -205,12 +205,12 @@ pub fn parse_handshake(rlp: UntrustedRlp) -> Result<(Status, Capabilities, Optio
 	};
 
 	let status = Status {
-		protocol_version: try!(parser.expect(Key::ProtocolVersion)),
+		protocol_version: parser.expect(Key::ProtocolVersion)?,
-		network_id: try!(parser.expect(Key::NetworkId)),
+		network_id: parser.expect(Key::NetworkId)?,
-		head_td: try!(parser.expect(Key::HeadTD)),
+		head_td: parser.expect(Key::HeadTD)?,
-		head_hash: try!(parser.expect(Key::HeadHash)),
+		head_hash: parser.expect(Key::HeadHash)?,
-		head_num: try!(parser.expect(Key::HeadNum)),
+		head_num: parser.expect(Key::HeadNum)?,
-		genesis_hash: try!(parser.expect(Key::GenesisHash)),
+		genesis_hash: parser.expect(Key::GenesisHash)?,
 		last_head: None,
 	};
 
@@ -298,10 +298,10 @@ pub fn parse_announcement(rlp: UntrustedRlp) -> Result<Announcement, DecoderErro
 	let mut last_key = None;
 
 	let mut announcement = Announcement {
-		head_hash: try!(rlp.val_at(0)),
+		head_hash: rlp.val_at(0)?,
-		head_num: try!(rlp.val_at(1)),
+		head_num: rlp.val_at(1)?,
-		head_td: try!(rlp.val_at(2)),
+		head_td: rlp.val_at(2)?,
-		reorg_depth: try!(rlp.val_at(3)),
+		reorg_depth: rlp.val_at(3)?,
 		serve_headers: false,
 		serve_state_since: None,
 		serve_chain_since: None,
@@ -313,14 +313,14 @@ pub fn parse_announcement(rlp: UntrustedRlp) -> Result<Announcement, DecoderErro
 		rlp: rlp,
 	};
 
-	while let Some((key, item)) = try!(parser.get_next()) {
+	while let Some((key, item)) = parser.get_next()? {
 		if Some(key) <= last_key { return Err(DecoderError::Custom("Invalid announcement key ordering")) }
 		last_key = Some(key);
 
 		match key {
 			Key::ServeHeaders => announcement.serve_headers = true,
-			Key::ServeStateSince => announcement.serve_state_since = Some(try!(item.as_val())),
+			Key::ServeStateSince => announcement.serve_state_since = Some(item.as_val()?),
-			Key::ServeChainSince => announcement.serve_chain_since = Some(try!(item.as_val())),
+			Key::ServeChainSince => announcement.serve_chain_since = Some(item.as_val()?),
 			Key::TxRelay => announcement.tx_relay = true,
 			_ => return Err(DecoderError::Custom("Nonsensical key in announcement")),
 		}

ethcore/light/src/net/tests/mod.rs

@@ -21,6 +21,7 @@ use ethcore::blockchain_info::BlockChainInfo;
 use ethcore::client::{BlockChainClient, EachBlockWith, TestBlockChainClient};
 use ethcore::ids::BlockId;
 use ethcore::transaction::PendingTransaction;
+use ethcore::encoded;
 use network::{PeerId, NodeId};
 
 use net::buffer_flow::FlowParams;
@@ -94,11 +95,11 @@ impl Provider for TestProvider {
 		None
 	}
 
-	fn block_header(&self, id: BlockId) -> Option<Bytes> {
+	fn block_header(&self, id: BlockId) -> Option<encoded::Header> {
 		self.0.client.block_header(id)
 	}
 
-	fn block_body(&self, id: BlockId) -> Option<Bytes> {
+	fn block_body(&self, id: BlockId) -> Option<encoded::Body> {
 		self.0.client.block_body(id)
 	}
 
@@ -122,7 +123,7 @@ impl Provider for TestProvider {
 		req.account_key.iter().chain(req.account_key.iter()).cloned().collect()
 	}
 
-	fn header_proof(&self, _req: request::HeaderProof) -> Option<(Bytes, Vec<Bytes>)> {
+	fn header_proof(&self, _req: request::HeaderProof) -> Option<(encoded::Header, Vec<Bytes>)> {
 		None
 	}
 
@@ -273,7 +274,7 @@ fn get_block_headers() {
 
 		response_stream.append(&req_id).append(&new_buf).begin_list(10);
 		for header in headers {
-			response_stream.append_raw(&header, 1);
+			response_stream.append_raw(&header.into_inner(), 1);
 		}
 
 		response_stream.out()
@@ -320,7 +321,7 @@ fn get_block_bodies() {
 
 		response_stream.append(&req_id).append(&new_buf).begin_list(10);
 		for body in bodies {
-			response_stream.append_raw(&body, 1);
+			response_stream.append_raw(&body.into_inner(), 1);
 		}
 
 		response_stream.out()

ethcore/light/src/on_demand/mod.rs

@@ -22,6 +22,7 @@ use std::collections::HashMap;
 
 use ethcore::ids::BlockId;
 use ethcore::block::Block;
+use ethcore::encoded;
 use ethcore::header::Header;
 use ethcore::receipt::Receipt;
 
@@ -33,7 +34,8 @@ use client::Client;
 use net::{Handler, Status, Capabilities, Announcement, EventContext, BasicContext, ReqId};
 use util::{Address, H256, RwLock};
 
-struct Account;
+/// Dummy type for "basic account"
+pub struct Account;
 
 // relevant peer info.
 struct Peer {
@@ -43,12 +45,12 @@ struct Peer {
 
 // request info and where to send the result.
 enum Request {
-	HeaderByNumber(u64, H256, Sender<Header>), // num + CHT root
+	HeaderByNumber(u64, H256, Sender<encoded::Header>), // num + CHT root
-	HeaderByHash(H256, Sender<Header>),
+	HeaderByHash(H256, Sender<encoded::Header>),
-	Block(Header, Sender<Block>),
+	Block(encoded::Header, Sender<encoded::Block>),
-	BlockReceipts(Header, Sender<Vec<Receipt>>),
+	BlockReceipts(encoded::Header, Sender<Vec<Receipt>>),
-	Account(Header, Address, Sender<Account>),
+	Account(encoded::Header, Address, Sender<Account>),
-	Storage(Header, Address, H256, Sender<H256>),
+	Storage(encoded::Header, Address, H256, Sender<H256>),
 }
 
 /// On demand request service. See module docs for more details.
@@ -61,7 +63,7 @@ pub struct OnDemand {
 
 impl Handler for OnDemand {
 	fn on_connect(&self, ctx: &EventContext, status: &Status, capabilities: &Capabilities) {
-		self.peers.write().insert(ctx.peer(), Peer { status: status.clone(), capabilities: capabilities.clone() })
+		self.peers.write().insert(ctx.peer(), Peer { status: status.clone(), capabilities: capabilities.clone() });
 	}
 
 	fn on_disconnect(&self, ctx: &EventContext, unfulfilled: &[ReqId]) {
@@ -71,7 +73,7 @@ impl Handler for OnDemand {
 
 impl OnDemand {
 	/// Request a header by block number and CHT root hash.
-	pub fn header_by_number(&self, ctx: &BasicContext, num: u64, cht_root: H256) -> Receiver<Header> {
+	pub fn header_by_number(&self, ctx: &BasicContext, num: u64, cht_root: H256) -> Receiver<encoded::Header> {
 		let (sender, receiver) = oneshot::channel();
 		self.dispatch_request(ctx, Request::HeaderByNumber(num, cht_root, sender));
 		receiver
@@ -80,7 +82,7 @@ impl OnDemand {
 	/// Request a header by hash. This is less accurate than by-number because we don't know
 	/// where in the chain this header lies, and therefore can't find a peer who is supposed to have
 	/// it as easily.
-	pub fn header_by_hash(&self, ctx: &BasicContext, hash: H256) -> Receiver<Header> {
+	pub fn header_by_hash(&self, ctx: &BasicContext, hash: H256) -> Receiver<encoded::Header> {
 		let (sender, receiver) = oneshot::channel();
 		self.dispatch_request(ctx, Request::HeaderByHash(hash, sender));
 		receiver
@@ -89,7 +91,7 @@ impl OnDemand {
 	/// Request a block, given its header. Block bodies are requestable by hash only,
 	/// and the header is required anyway to verify and complete the block body
 	/// -- this just doesn't obscure the network query.
-	pub fn block(&self, ctx: &BasicContext, header: Header) -> Receiver<Block> {
+	pub fn block(&self, ctx: &BasicContext, header: encoded::Header) -> Receiver<encoded::Block> {
 		let (sender, receiver) = oneshot::channel();
 		self.dispatch_request(ctx, Request::Block(header, sender));
 		receiver
@@ -97,7 +99,7 @@ impl OnDemand {
 
 	/// Request the receipts for a block. The header serves two purposes:
 	/// provide the block hash to fetch receipts for, and for verification of the receipts root.
-	pub fn block_receipts(&self, ctx: &BasicContext, header: Header) -> Receiver<Vec<Receipt>> {
+	pub fn block_receipts(&self, ctx: &BasicContext, header: encoded::Header) -> Receiver<Vec<Receipt>> {
 		let (sender, receiver) = oneshot::channel();
 		self.dispatch_request(ctx, Request::BlockReceipts(header, sender));
 		receiver
@@ -105,14 +107,14 @@ impl OnDemand {
 
 	/// Request an account by address and block header -- which gives a hash to query and a state root
 	/// to verify against.
-	pub fn account(&self, ctx: &BasicContext, header: Header, address: Address) -> Receiver<Account> {
+	pub fn account(&self, ctx: &BasicContext, header: encoded::Header, address: Address) -> Receiver<Account> {
 		let (sender, receiver) = oneshot::channel();
 		self.dispatch_request(ctx, Request::Account(header, address, sender));
 		receiver
 	}
 
 	/// Request account storage value by block header, address, and key.
-	pub fn storage(&self, ctx: &BasicContext, header: Header, address: Address, key: H256) -> Receiver<H256> {
+	pub fn storage(&self, ctx: &BasicContext, header: encoded::Header, address: Address, key: H256) -> Receiver<H256> {
 		let (sender, receiver) = oneshot::channel();
 		self.dispatch_request(ctx, Request::Storage(header, address, key, sender));
 		receiver

ethcore/light/src/provider.rs

@@ -21,6 +21,7 @@ use ethcore::blockchain_info::BlockChainInfo;
 use ethcore::client::{BlockChainClient, ProvingBlockChainClient};
 use ethcore::transaction::PendingTransaction;
 use ethcore::ids::BlockId;
+use ethcore::encoded;
 
 use util::{Bytes, H256};
 
@@ -52,9 +53,8 @@ pub trait Provider: Send + Sync {
 	///
 	/// The returned vector may have any length in the range [0, `max`], but the
 	/// results within must adhere to the `skip` and `reverse` parameters.
-	fn block_headers(&self, req: request::Headers) -> Vec<Bytes> {
+	fn block_headers(&self, req: request::Headers) -> Vec<encoded::Header> {
 		use request::HashOrNumber;
-		use ethcore::views::HeaderView;
 
 		if req.max == 0 { return Vec::new() }
 
@@ -67,9 +67,9 @@ pub trait Provider: Send + Sync {
 					return Vec::new();
 				}
 				Some(header) => {
-					let num = HeaderView::new(&header).number();
+					let num = header.number();
 					let canon_hash = self.block_header(BlockId::Number(num))
-						.map(|h| HeaderView::new(&h).hash());
+						.map(|h| h.hash());
 
 					if req.max == 1 || canon_hash != Some(hash) {
 						// Non-canonical header or single header requested.
@@ -92,19 +92,18 @@ pub trait Provider: Send + Sync {
 	}
 
 	/// Get a block header by id.
-	fn block_header(&self, id: BlockId) -> Option<Bytes>;
+	fn block_header(&self, id: BlockId) -> Option<encoded::Header>;
 
 	/// Provide as many as possible of the requested blocks (minus the headers) encoded
 	/// in RLP format.
-	fn block_bodies(&self, req: request::Bodies) -> Vec<Bytes> {
+	fn block_bodies(&self, req: request::Bodies) -> Vec<Option<encoded::Body>> {
 		req.block_hashes.into_iter()
 			.map(|hash| self.block_body(BlockId::Hash(hash)))
-			.map(|body| body.unwrap_or_else(|| ::rlp::EMPTY_LIST_RLP.to_vec()))
 			.collect()
 	}
 
 	/// Get a block body by id.
-	fn block_body(&self, id: BlockId) -> Option<Bytes>;
+	fn block_body(&self, id: BlockId) -> Option<encoded::Body>;
 
 	/// Provide the receipts as many as possible of the requested blocks.
 	/// Returns a vector of RLP-encoded lists of receipts.
@@ -169,7 +168,7 @@ pub trait Provider: Send + Sync {
 				None => rlp::EMPTY_LIST_RLP.to_vec(),
 				Some((header, proof)) => {
 					let mut stream = RlpStream::new_list(2);
-					stream.append_raw(&header, 1).begin_list(proof.len());
+					stream.append_raw(&header.into_inner(), 1).begin_list(proof.len());
 
 					for node in proof {
 						stream.append_raw(&node, 1);
@@ -184,7 +183,7 @@ pub trait Provider: Send + Sync {
 	/// Provide a header proof from a given Canonical Hash Trie as well as the
 	/// corresponding header. The first element is the block header and the
 	/// second is a merkle proof of the CHT.
-	fn header_proof(&self, req: request::HeaderProof) -> Option<(Bytes, Vec<Bytes>)>;
+	fn header_proof(&self, req: request::HeaderProof) -> Option<(encoded::Header, Vec<Bytes>)>;
 
 	/// Provide pending transactions.
 	fn ready_transactions(&self) -> Vec<PendingTransaction>;
@@ -204,11 +203,11 @@ impl<T: ProvingBlockChainClient + ?Sized> Provider for T {
 		Some(self.pruning_info().earliest_state)
 	}
 
-	fn block_header(&self, id: BlockId) -> Option<Bytes> {
+	fn block_header(&self, id: BlockId) -> Option<encoded::Header> {
 		BlockChainClient::block_header(self, id)
 	}
 
-	fn block_body(&self, id: BlockId) -> Option<Bytes> {
+	fn block_body(&self, id: BlockId) -> Option<encoded::Body> {
 		BlockChainClient::block_body(self, id)
 	}
 
@@ -227,7 +226,7 @@ impl<T: ProvingBlockChainClient + ?Sized> Provider for T {
 		self.code_by_hash(req.account_key, BlockId::Hash(req.block_hash))
 	}
 
-	fn header_proof(&self, _req: request::HeaderProof) -> Option<(Bytes, Vec<Bytes>)> {
+	fn header_proof(&self, _req: request::HeaderProof) -> Option<(encoded::Header, Vec<Bytes>)> {
 		None
 	}
 

ethcore/res/constructor.json

@@ -0,0 +1,30 @@
+{
+	"name": "GenesisConstructor",
+	"engine": {
+		"null": null
+	},
+	"params": {
+		"accountStartNonce": "0x0",
+		"maximumExtraDataSize": "0x20",
+		"minGasLimit": "0x1388",
+		"networkID" : "0x2"
+	},
+	"genesis": {
+		"seal": {
+			"generic": "0x"
+		},
+		"difficulty": "0x20000",
+		"author": "0x0000000000000000000000000000000000000000",
+		"timestamp": "0x00",
+		"parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
+		"extraData": "0x",
+		"gasLimit": "0x2fefd8"
+	},
+	"accounts": {
+		"0000000000000000000000000000000000000001": { "balance": "1", "builtin": { "name": "ecrecover", "pricing": { "linear": { "base": 3000, "word": 0 } } } },
+		"0000000000000000000000000000000000000002": { "balance": "1", "builtin": { "name": "sha256", "pricing": { "linear": { "base": 60, "word": 12 } } } },
+		"0000000000000000000000000000000000000003": { "balance": "1", "builtin": { "name": "ripemd160", "pricing": { "linear": { "base": 600, "word": 120 } } } },
+		"0000000000000000000000000000000000000004": { "balance": "1", "builtin": { "name": "identity", "pricing": { "linear": { "base": 15, "word": 3 } } } },
+		"0000000000000000000000000000000000000005": { "balance": "1", "constructor": "60606040526000805460ff19166001179055346000575b6075806100246000396000f300606060405263ffffffff60e060020a60003504166394b91deb81146022575b6000565b34600057602c6040565b604080519115158252519081900360200190f35b60005460ff16815600a165627a7a723058207882eb60ebce23178b3fa06d4cd8e5adc17711937ccddacb18a04abca2a2c9ee0029" }
+	}
+}

ethcore/src/account_provider/mod.rs

@@ -127,32 +127,32 @@ impl AccountProvider {
 		let acc = Random.generate().expect("secp context has generation capabilities; qed");
 		let public = acc.public().clone();
 		let secret = acc.secret().clone();
-		let address = try!(self.sstore.insert_account(secret, password));
+		let address = self.sstore.insert_account(secret, password)?;
 		Ok((address, public))
 	}
 
 	/// Inserts new account into underlying store.
 	/// Does not unlock account!
 	pub fn insert_account(&self, secret: Secret, password: &str) -> Result<Address, Error> {
-		let address = try!(self.sstore.insert_account(secret, password));
+		let address = self.sstore.insert_account(secret, password)?;
 		Ok(address)
 	}
 
 	/// Import a new presale wallet.
 	pub fn import_presale(&self, presale_json: &[u8], password: &str) -> Result<Address, Error> {
-		let address = try!(self.sstore.import_presale(presale_json, password));
+		let address = self.sstore.import_presale(presale_json, password)?;
 		Ok(Address::from(address).into())
 	}
 
 	/// Import a new presale wallet.
 	pub fn import_wallet(&self, json: &[u8], password: &str) -> Result<Address, Error> {
-		let address = try!(self.sstore.import_wallet(json, password));
+		let address = self.sstore.import_wallet(json, password)?;
 		Ok(Address::from(address).into())
 	}
 
 	/// Returns addresses of all accounts.
 	pub fn accounts(&self) -> Result<Vec<Address>, Error> {
-		let accounts = try!(self.sstore.accounts());
+		let accounts = self.sstore.accounts()?;
 		Ok(accounts)
 	}
 
@@ -229,7 +229,7 @@ impl AccountProvider {
 
 	/// Returns each account along with name and meta.
 	pub fn accounts_info(&self) -> Result<HashMap<Address, AccountMeta>, Error> {
-		let r: HashMap<Address, AccountMeta> = try!(self.sstore.accounts())
+		let r: HashMap<Address, AccountMeta> = self.sstore.accounts()?
 			.into_iter()
 			.map(|a| (a.clone(), self.account_meta(a).ok().unwrap_or_default()))
 			.collect();
@@ -239,21 +239,21 @@ impl AccountProvider {
 	/// Returns each account along with name and meta.
 	pub fn account_meta(&self, account: Address) -> Result<AccountMeta, Error> {
 		Ok(AccountMeta {
-			name: try!(self.sstore.name(&account)),
+			name: self.sstore.name(&account)?,
-			meta: try!(self.sstore.meta(&account)),
+			meta: self.sstore.meta(&account)?,
 			uuid: self.sstore.uuid(&account).ok().map(Into::into),	// allowed to not have a Uuid
 		})
 	}
 
 	/// Returns each account along with name and meta.
 	pub fn set_account_name(&self, account: Address, name: String) -> Result<(), Error> {
-		try!(self.sstore.set_name(&account, name));
+		self.sstore.set_name(&account, name)?;
 		Ok(())
 	}
 
 	/// Returns each account along with name and meta.
 	pub fn set_account_meta(&self, account: Address, meta: String) -> Result<(), Error> {
-		try!(self.sstore.set_meta(&account, meta));
+		self.sstore.set_meta(&account, meta)?;
 		Ok(())
 	}
 
@@ -265,7 +265,7 @@ impl AccountProvider {
 
 	/// Permanently removes an account.
 	pub fn kill_account(&self, account: &Address, password: &str) -> Result<(), Error> {
-		try!(self.sstore.remove_account(account, &password));
+		self.sstore.remove_account(account, &password)?;
 		Ok(())
 	}
 
@@ -278,7 +278,7 @@ impl AccountProvider {
 	fn unlock_account(&self, account: Address, password: String, unlock: Unlock) -> Result<(), Error> {
 		// verify password by signing dump message
 		// result may be discarded
-		let _ = try!(self.sstore.sign(&account, &password, &Default::default()));
+		let _ = self.sstore.sign(&account, &password, &Default::default())?;
 
 		// check if account is already unlocked pernamently, if it is, do nothing
 		let mut unlocked = self.unlocked.write();
@@ -299,7 +299,7 @@ impl AccountProvider {
 
 	fn password(&self, account: &Address) -> Result<String, Error> {
 		let mut unlocked = self.unlocked.write();
-		let data = try!(unlocked.get(account).ok_or(Error::NotUnlocked)).clone();
+		let data = unlocked.get(account).ok_or(Error::NotUnlocked)?.clone();
 		if let Unlock::Temp = data.unlock {
 			unlocked.remove(account).expect("data exists: so key must exist: qed");
 		}
@@ -335,25 +335,25 @@ impl AccountProvider {
 
 	/// Signs the message. If password is not provided the account must be unlocked.
 	pub fn sign(&self, account: Address, password: Option<String>, message: Message) -> Result<Signature, Error> {
-		let password = try!(password.map(Ok).unwrap_or_else(|| self.password(&account)));
+		let password = password.map(Ok).unwrap_or_else(|| self.password(&account))?;
-		Ok(try!(self.sstore.sign(&account, &password, &message)))
+		Ok(self.sstore.sign(&account, &password, &message)?)
 	}
 
 	/// Signs given message with supplied token. Returns a token to use in next signing within this session.
 	pub fn sign_with_token(&self, account: Address, token: AccountToken, message: Message) -> Result<(Signature, AccountToken), Error> {
-		let is_std_password = try!(self.sstore.test_password(&account, &token));
+		let is_std_password = self.sstore.test_password(&account, &token)?;
 
 		let new_token = random_string(16);
 		let signature = if is_std_password {
 			// Insert to transient store
-			try!(self.sstore.copy_account(&self.transient_sstore, &account, &token, &new_token));
+			self.sstore.copy_account(&self.transient_sstore, &account, &token, &new_token)?;
 			// sign
-			try!(self.sstore.sign(&account, &token, &message))
+			self.sstore.sign(&account, &token, &message)?
 		} else {
 			// check transient store
-			try!(self.transient_sstore.change_password(&account, &token, &new_token));
+			self.transient_sstore.change_password(&account, &token, &new_token)?;
 			// and sign
-			try!(self.transient_sstore.sign(&account, &new_token, &message))
+			self.transient_sstore.sign(&account, &new_token, &message)?
 		};
 
 		Ok((signature, new_token))
@@ -363,19 +363,19 @@ impl AccountProvider {
 	pub fn decrypt_with_token(&self, account: Address, token: AccountToken, shared_mac: &[u8], message: &[u8])
 		-> Result<(Vec<u8>, AccountToken), Error>
 	{
-		let is_std_password = try!(self.sstore.test_password(&account, &token));
+		let is_std_password = self.sstore.test_password(&account, &token)?;
 
 		let new_token = random_string(16);
 		let message = if is_std_password {
 			// Insert to transient store
-			try!(self.sstore.copy_account(&self.transient_sstore, &account, &token, &new_token));
+			self.sstore.copy_account(&self.transient_sstore, &account, &token, &new_token)?;
 			// decrypt
-			try!(self.sstore.decrypt(&account, &token, shared_mac, message))
+			self.sstore.decrypt(&account, &token, shared_mac, message)?
 		} else {
 			// check transient store
-			try!(self.transient_sstore.change_password(&account, &token, &new_token));
+			self.transient_sstore.change_password(&account, &token, &new_token)?;
 			// and decrypt
-			try!(self.transient_sstore.decrypt(&account, &token, shared_mac, message))
+			self.transient_sstore.decrypt(&account, &token, shared_mac, message)?
 		};
 
 		Ok((message, new_token))
@@ -383,8 +383,8 @@ impl AccountProvider {
 
 	/// Decrypts a message. If password is not provided the account must be unlocked.
 	pub fn decrypt(&self, account: Address, password: Option<String>, shared_mac: &[u8], message: &[u8]) -> Result<Vec<u8>, Error> {
-		let password = try!(password.map(Ok).unwrap_or_else(|| self.password(&account)));
+		let password = password.map(Ok).unwrap_or_else(|| self.password(&account))?;
-		Ok(try!(self.sstore.decrypt(&account, &password, shared_mac, message)))
+		Ok(self.sstore.decrypt(&account, &password, shared_mac, message)?)
 	}
 
 	/// Returns the underlying `SecretStore` reference if one exists.

ethcore/src/block.rs

@@ -67,7 +67,7 @@ impl Block {
 
 impl Decodable for Block {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		if decoder.as_raw().len() != try!(decoder.as_rlp().payload_info()).total() {
+		if decoder.as_raw().len() != decoder.as_rlp().payload_info()?.total() {
 			return Err(DecoderError::RlpIsTooBig);
 		}
 		let d = decoder.as_rlp();
@@ -75,9 +75,9 @@ impl Decodable for Block {
 			return Err(DecoderError::RlpIncorrectListLen);
 		}
 		Ok(Block {
-			header: try!(d.val_at(0)),
+			header: d.val_at(0)?,
-			transactions: try!(d.val_at(1)),
+			transactions: d.val_at(1)?,
-			uncles: try!(d.val_at(2)),
+			uncles: d.val_at(2)?,
 		})
 	}
 }
@@ -252,7 +252,7 @@ impl<'x> OpenBlock<'x> {
 		gas_range_target: (U256, U256),
 		extra_data: Bytes,
 	) -> Result<Self, Error> {
-		let state = try!(State::from_existing(db, parent.state_root().clone(), engine.account_start_nonce(), factories));
+		let state = State::from_existing(db, parent.state_root().clone(), engine.account_start_nonce(), factories)?;
 		let mut r = OpenBlock {
 			block: ExecutedBlock::new(state, tracing),
 			engine: engine,
@@ -521,12 +521,12 @@ pub fn enact(
 ) -> Result<LockedBlock, Error> {
 	{
 		if ::log::max_log_level() >= ::log::LogLevel::Trace {
-			let s = try!(State::from_existing(db.boxed_clone(), parent.state_root().clone(), engine.account_start_nonce(), factories.clone()));
+			let s = State::from_existing(db.boxed_clone(), parent.state_root().clone(), engine.account_start_nonce(), factories.clone())?;
 			trace!(target: "enact", "num={}, root={}, author={}, author_balance={}\n", header.number(), s.root(), header.author(), s.balance(&header.author()));
 		}
 	}
 
-	let mut b = try!(OpenBlock::new(engine, factories, tracing, db, parent, last_hashes, Address::new(), (3141562.into(), 31415620.into()), vec![]));
+	let mut b = OpenBlock::new(engine, factories, tracing, db, parent, last_hashes, Address::new(), (3141562.into(), 31415620.into()), vec![])?;
 	b.set_difficulty(*header.difficulty());
 	b.set_gas_limit(*header.gas_limit());
 	b.set_timestamp(header.timestamp());
@@ -536,9 +536,9 @@ pub fn enact(
 	b.set_transactions_root(header.transactions_root().clone());
 	b.set_receipts_root(header.receipts_root().clone());
 
-	try!(push_transactions(&mut b, transactions));
+	push_transactions(&mut b, transactions)?;
 	for u in uncles {
-		try!(b.push_uncle(u.clone()));
+		b.push_uncle(u.clone())?;
 	}
 	Ok(b.close_and_lock())
 }
@@ -547,7 +547,7 @@ pub fn enact(
 #[cfg(not(feature = "slow-blocks"))]
 fn push_transactions(block: &mut OpenBlock, transactions: &[SignedTransaction]) -> Result<(), Error> {
 	for t in transactions {
-		try!(block.push_transaction(t.clone(), None));
+		block.push_transaction(t.clone(), None)?;
 	}
 	Ok(())
 }
@@ -560,7 +560,7 @@ fn push_transactions(block: &mut OpenBlock, transactions: &[SignedTransaction])
 	for t in transactions {
 		let hash = t.hash();
 		let start = time::Instant::now();
-		try!(block.push_transaction(t.clone(), None));
+		block.push_transaction(t.clone(), None)?;
 		let took = start.elapsed();
 		if took > time::Duration::from_millis(slow_tx) {
 			warn!("Heavy transaction in block {:?}: {:?}", block.header().number(), hash);
@@ -595,9 +595,8 @@ mod tests {
 	use factory::Factories;
 	use state_db::StateDB;
 	use views::BlockView;
-	use util::{Address, TrieFactory};
+	use util::Address;
 	use util::hash::FixedHash;
-	use util::trie::TrieSpec;
 	use std::sync::Arc;
 
 	/// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
@@ -628,7 +627,7 @@ mod tests {
 		factories: Factories,
 	) -> Result<SealedBlock, Error> {
 		let header = BlockView::new(block_bytes).header_view();
-		Ok(try!(try!(enact_bytes(block_bytes, engine, tracing, db, parent, last_hashes, factories)).seal(engine, header.seal())))
+		Ok(enact_bytes(block_bytes, engine, tracing, db, parent, last_hashes, factories)?.seal(engine, header.seal())?)
 	}
 
 	#[test]
@@ -637,8 +636,7 @@ mod tests {
 		let spec = Spec::new_test();
 		let genesis_header = spec.genesis_header();
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(&*spec.engine, Default::default(), false, db, &genesis_header, last_hashes, Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b = b.close_and_lock();
@@ -653,8 +651,7 @@ mod tests {
 		let genesis_header = spec.genesis_header();
 
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes.clone(), Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap()
 			.close_and_lock().seal(engine, vec![]).unwrap();
@@ -662,8 +659,7 @@ mod tests {
 		let orig_db = b.drain();
 
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let e = enact_and_seal(&orig_bytes, engine, false, db, &genesis_header, last_hashes, Default::default()).unwrap();
 
 		assert_eq!(e.rlp_bytes(), orig_bytes);
@@ -681,8 +677,7 @@ mod tests {
 		let genesis_header = spec.genesis_header();
 
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let mut open_block = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes.clone(), Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let mut uncle1_header = Header::new();
@@ -697,8 +692,7 @@ mod tests {
 		let orig_db = b.drain();
 
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let e = enact_and_seal(&orig_bytes, engine, false, db, &genesis_header, last_hashes, Default::default()).unwrap();
 
 		let bytes = e.rlp_bytes();

ethcore/src/blockchain/blockchain.rs

@@ -35,6 +35,7 @@ use blockchain::{CacheSize, ImportRoute, Config};
 use db::{self, Writable, Readable, CacheUpdatePolicy};
 use cache_manager::CacheManager;
 use engines::Engine;
+use encoded;
 
 const LOG_BLOOMS_LEVELS: usize = 3;
 const LOG_BLOOMS_ELEMENTS_PER_INDEX: usize = 16;
@@ -64,7 +65,7 @@ pub trait BlockProvider {
 		self.best_ancient_block().map(|h| self.block_number(&h).expect("Ancient block is always set to an existing block or `None`. Existing block always has a number; qed"))
 	}
 	/// Get raw block data
-	fn block(&self, hash: &H256) -> Option<Bytes>;
+	fn block(&self, hash: &H256) -> Option<encoded::Block>;
 
 	/// Get the familial details concerning a block.
 	fn block_details(&self, hash: &H256) -> Option<BlockDetails>;
@@ -80,25 +81,25 @@ pub trait BlockProvider {
 
 	/// Get the partial-header of a block.
 	fn block_header(&self, hash: &H256) -> Option<Header> {
-		self.block_header_data(hash).map(|header| decode(&header))
+		self.block_header_data(hash).map(|header| header.decode())
 	}
 
 	/// Get the header RLP of a block.
-	fn block_header_data(&self, hash: &H256) -> Option<Bytes>;
+	fn block_header_data(&self, hash: &H256) -> Option<encoded::Header>;
 
 	/// Get the block body (uncles and transactions).
-	fn block_body(&self, hash: &H256) -> Option<Bytes>;
+	fn block_body(&self, hash: &H256) -> Option<encoded::Body>;
 
 	/// Get a list of uncles for a given block.
 	/// Returns None if block does not exist.
 	fn uncles(&self, hash: &H256) -> Option<Vec<Header>> {
-		self.block_body(hash).map(|bytes| BodyView::new(&bytes).uncles())
+		self.block_body(hash).map(|body| body.uncles())
 	}
 
 	/// Get a list of uncle hashes for a given block.
 	/// Returns None if block does not exist.
 	fn uncle_hashes(&self, hash: &H256) -> Option<Vec<H256>> {
-		self.block_body(hash).map(|bytes| BodyView::new(&bytes).uncle_hashes())
+		self.block_body(hash).map(|body| body.uncle_hashes())
 	}
 
 	/// Get the number of given block's hash.
@@ -109,8 +110,8 @@ pub trait BlockProvider {
 	/// Get transaction with given transaction hash.
 	fn transaction(&self, address: &TransactionAddress) -> Option<LocalizedTransaction> {
 		self.block_body(&address.block_hash)
-			.and_then(|bytes| self.block_number(&address.block_hash)
+			.and_then(|body| self.block_number(&address.block_hash)
-			.and_then(|n| BodyView::new(&bytes).localized_transaction_at(&address.block_hash, n, address.index)))
+			.and_then(|n| body.view().localized_transaction_at(&address.block_hash, n, address.index)))
 	}
 
 	/// Get transaction receipt.
@@ -122,8 +123,8 @@ pub trait BlockProvider {
 	/// Returns None if block does not exist.
 	fn transactions(&self, hash: &H256) -> Option<Vec<LocalizedTransaction>> {
 		self.block_body(hash)
-			.and_then(|bytes| self.block_number(hash)
+			.and_then(|body| self.block_number(hash)
-			.map(|n| BodyView::new(&bytes).localized_transactions(hash, n)))
+			.map(|n| body.view().localized_transactions(hash, n)))
 	}
 
 	/// Returns reference to genesis hash.
@@ -224,27 +225,27 @@ impl BlockProvider for BlockChain {
 	}
 
 	/// Get raw block data
-	fn block(&self, hash: &H256) -> Option<Bytes> {
+	fn block(&self, hash: &H256) -> Option<encoded::Block> {
 		match (self.block_header_data(hash), self.block_body(hash)) {
 			(Some(header), Some(body)) => {
 				let mut block = RlpStream::new_list(3);
-				let body_rlp = Rlp::new(&body);
+				let body_rlp = body.rlp();
-				block.append_raw(&header, 1);
+				block.append_raw(header.rlp().as_raw(), 1);
 				block.append_raw(body_rlp.at(0).as_raw(), 1);
 				block.append_raw(body_rlp.at(1).as_raw(), 1);
-				Some(block.out())
+				Some(encoded::Block::new(block.out()))
 			},
 			_ => None,
 		}
 	}
 
 	/// Get block header data
-	fn block_header_data(&self, hash: &H256) -> Option<Bytes> {
+	fn block_header_data(&self, hash: &H256) -> Option<encoded::Header> {
 		// Check cache first
 		{
 			let read = self.block_headers.read();
 			if let Some(v) = read.get(hash) {
-				return Some(v.clone());
+				return Some(encoded::Header::new(v.clone()));
 			}
 		}
 
@@ -252,7 +253,9 @@ impl BlockProvider for BlockChain {
 		{
 			let best_block = self.best_block.read();
 			if &best_block.hash == hash {
-				return Some(Rlp::new(&best_block.block).at(0).as_raw().to_vec());
+				return Some(encoded::Header::new(
+					Rlp::new(&best_block.block).at(0).as_raw().to_vec()
+				))
 			}
 		}
 
@@ -265,7 +268,7 @@ impl BlockProvider for BlockChain {
 				let bytes: Bytes = UntrustedRlp::new(&b).decompress(RlpType::Blocks).to_vec();
 				let mut write = self.block_headers.write();
 				write.insert(hash.clone(), bytes.clone());
-				Some(bytes)
+				Some(encoded::Header::new(bytes))
 			},
 			None => None
 		};
@@ -275,12 +278,12 @@ impl BlockProvider for BlockChain {
 	}
 
 	/// Get block body data
-	fn block_body(&self, hash: &H256) -> Option<Bytes> {
+	fn block_body(&self, hash: &H256) -> Option<encoded::Body> {
 		// Check cache first
 		{
 			let read = self.block_bodies.read();
 			if let Some(v) = read.get(hash) {
-				return Some(v.clone());
+				return Some(encoded::Body::new(v.clone()));
 			}
 		}
 
@@ -288,7 +291,7 @@ impl BlockProvider for BlockChain {
 		{
 			let best_block = self.best_block.read();
 			if &best_block.hash == hash {
-				return Some(Self::block_to_body(&best_block.block));
+				return Some(encoded::Body::new(Self::block_to_body(&best_block.block)));
 			}
 		}
 
@@ -301,7 +304,7 @@ impl BlockProvider for BlockChain {
 				let bytes: Bytes = UntrustedRlp::new(&b).decompress(RlpType::Blocks).to_vec();
 				let mut write = self.block_bodies.write();
 				write.insert(hash.clone(), bytes.clone());
-				Some(bytes)
+				Some(encoded::Body::new(bytes))
 			},
 			None => None
 		};
@@ -358,7 +361,7 @@ impl BlockProvider for BlockChain {
 		let mut logs = blocks.into_iter()
 			.filter_map(|number| self.block_hash(number).map(|hash| (number, hash)))
 			.filter_map(|(number, hash)| self.block_receipts(&hash).map(|r| (number, hash, r.receipts)))
-			.filter_map(|(number, hash, receipts)| self.block_body(&hash).map(|ref b| (number, hash, receipts, BodyView::new(b).transaction_hashes())))
+			.filter_map(|(number, hash, receipts)| self.block_body(&hash).map(|ref b| (number, hash, receipts, b.transaction_hashes())))
 			.flat_map(|(number, hash, mut receipts, mut hashes)| {
 				if receipts.len() != hashes.len() {
 					warn!("Block {} ({}) has different number of receipts ({}) to transactions ({}). Database corrupt?", number, hash, receipts.len(), hashes.len());
@@ -484,7 +487,7 @@ impl BlockChain {
 			// Fetch best block details
 			let best_block_number = bc.block_number(&best_block_hash).unwrap();
 			let best_block_total_difficulty = bc.block_details(&best_block_hash).unwrap().total_difficulty;
-			let best_block_rlp = bc.block(&best_block_hash).unwrap();
+			let best_block_rlp = bc.block(&best_block_hash).unwrap().into_inner();
 
 			let raw_first = bc.db.get(db::COL_EXTRA, b"first").unwrap().map(|v| v.to_vec());
 			let mut best_ancient = bc.db.get(db::COL_EXTRA, b"ancient").unwrap().map(|h| H256::from_slice(&h));
@@ -578,7 +581,7 @@ impl BlockChain {
 				batch.put(db::COL_EXTRA, b"best", &hash);
 
 				let best_block_total_difficulty = self.block_details(&hash).unwrap().total_difficulty;
-				let best_block_rlp = self.block(&hash).unwrap();
+				let best_block_rlp = self.block(&hash).unwrap().into_inner();
 
 				let mut best_block = self.best_block.write();
 				*best_block = BestBlock {
@@ -862,7 +865,7 @@ impl BlockChain {
 		let number = header.number();
 		let parent_hash = header.parent_hash();
 		let parent_details = self.block_details(&parent_hash).unwrap_or_else(|| panic!("Invalid parent hash: {:?}", parent_hash));
-		let is_new_best = self.engine.is_new_best_block(self.best_block_total_difficulty(), HeaderView::new(&self.best_block_header()), &parent_details, header);
+		let is_new_best = self.engine.is_new_best_block(self.best_block_total_difficulty(), self.best_block_header().view(), &parent_details, header);
 
 		BlockInfo {
 			hash: hash,
@@ -1108,8 +1111,8 @@ impl BlockChain {
 			BlockLocation::BranchBecomingCanonChain(ref data) => {
 				let addresses = data.enacted.iter()
 					.flat_map(|hash| {
-						let bytes = self.block_body(hash).expect("Enacted block must be in database.");
+						let body = self.block_body(hash).expect("Enacted block must be in database.");
-						let hashes = BodyView::new(&bytes).transaction_hashes();
+						let hashes = body.transaction_hashes();
 						hashes.into_iter()
 							.enumerate()
 							.map(|(i, tx_hash)| (tx_hash, Some(TransactionAddress {
@@ -1129,8 +1132,8 @@ impl BlockChain {
 					});
 
 				let retracted = data.retracted.iter().flat_map(|hash| {
-					let bytes = self.block_body(hash).expect("Retracted block must be in database.");
+					let body = self.block_body(hash).expect("Retracted block must be in database.");
-					let hashes = BodyView::new(&bytes).transaction_hashes();
+					let hashes = body.transaction_hashes();
 					hashes.into_iter().map(|hash| (hash, None)).collect::<HashMap<H256, Option<TransactionAddress>>>()
 				});
 
@@ -1179,7 +1182,7 @@ impl BlockChain {
 
 				let mut blooms: Vec<bc::Bloom> = data.enacted.iter()
 					.map(|hash| self.block_header_data(hash).unwrap())
-					.map(|bytes| HeaderView::new(&bytes).log_bloom())
+					.map(|h| h.log_bloom())
 					.map(Bloom::from)
 					.map(Into::into)
 					.collect();
@@ -1212,9 +1215,10 @@ impl BlockChain {
 	}
 
 	/// Get best block header
-	pub fn best_block_header(&self) -> Bytes {
+	pub fn best_block_header(&self) -> encoded::Header {
 		let block = self.best_block.read();
-		BlockView::new(&block.block).header_view().rlp().as_raw().to_vec()
+		let raw = BlockView::new(&block.block).header_view().rlp().as_raw().to_vec();
+		encoded::Header::new(raw)
 	}
 
 	/// Get current cache size.

ethcore/src/blockchain/extras.rs

@@ -157,10 +157,10 @@ impl Decodable for BlockDetails {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let details = BlockDetails {
-			number: try!(d.val_at(0)),
+			number: d.val_at(0)?,
-			total_difficulty: try!(d.val_at(1)),
+			total_difficulty: d.val_at(1)?,
-			parent: try!(d.val_at(2)),
+			parent: d.val_at(2)?,
-			children: try!(d.val_at(3)),
+			children: d.val_at(3)?,
 		};
 		Ok(details)
 	}
@@ -193,8 +193,8 @@ impl Decodable for TransactionAddress {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let tx_address = TransactionAddress {
-			block_hash: try!(d.val_at(0)),
+			block_hash: d.val_at(0)?,
-			index: try!(d.val_at(1)),
+			index: d.val_at(1)?,
 		};
 
 		Ok(tx_address)
@@ -226,7 +226,7 @@ impl BlockReceipts {
 impl Decodable for BlockReceipts {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		Ok(BlockReceipts {
-			receipts: try!(Decodable::decode(decoder))
+			receipts: Decodable::decode(decoder)?
 		})
 	}
 }

ethcore/src/blooms/bloom_group.rs

@@ -53,7 +53,7 @@ impl Into<bc::BloomGroup> for BloomGroup {
 
 impl Decodable for BloomGroup {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		let blooms = try!(Decodable::decode(decoder));
+		let blooms = Decodable::decode(decoder)?;
 		let group = BloomGroup {
 			blooms: blooms
 		};

ethcore/src/client/client.rs

@@ -32,7 +32,7 @@ use util::kvdb::*;
 
 // other
 use io::*;
-use views::{HeaderView, BodyView, BlockView};
+use views::BlockView;
 use error::{ImportError, ExecutionError, CallError, BlockError, ImportResult, Error as EthcoreError};
 use header::BlockNumber;
 use state::{State, CleanupMode};
@@ -67,10 +67,11 @@ use evm::{Factory as EvmFactory, Schedule};
 use miner::{Miner, MinerService};
 use snapshot::{self, io as snapshot_io};
 use factory::Factories;
-use rlp::{decode, View, UntrustedRlp};
+use rlp::{View, UntrustedRlp};
 use state_db::StateDB;
 use rand::OsRng;
 use client::registry::Registry;
+use encoded;
 
 // re-export
 pub use types::blockchain_info::BlockChainInfo;
@@ -167,26 +168,33 @@ impl Client {
 	) -> Result<Arc<Client>, ClientError> {
 
 		let path = path.to_path_buf();
-		let gb = spec.genesis_block();
+		let db = Arc::new(Database::open(&db_config, &path.to_str().expect("DB path could not be converted to string.")).map_err(ClientError::Database)?);
-
-		let db = Arc::new(try!(Database::open(&db_config, &path.to_str().expect("DB path could not be converted to string.")).map_err(ClientError::Database)));
-		let chain = Arc::new(BlockChain::new(config.blockchain.clone(), &gb, db.clone(), spec.engine.clone()));
-		let tracedb = RwLock::new(TraceDB::new(config.tracing.clone(), db.clone(), chain.clone()));
-
 		let trie_spec = match config.fat_db {
 			true => TrieSpec::Fat,
 			false => TrieSpec::Secure,
 		};
 
 		let trie_factory = TrieFactory::new(trie_spec);
+		let factories = Factories {
+			vm: EvmFactory::new(config.vm_type.clone(), config.jump_table_size),
+			trie: trie_factory,
+			accountdb: Default::default(),
+		};
+
 		let journal_db = journaldb::new(db.clone(), config.pruning, ::db::COL_STATE);
 		let mut state_db = StateDB::new(journal_db, config.state_cache_size);
-		if state_db.journal_db().is_empty() && try!(spec.ensure_db_good(&mut state_db, &trie_factory)) {
+		if state_db.journal_db().is_empty() {
+			// Sets the correct state root.
+			state_db = spec.ensure_db_good(state_db, &factories)?;
 			let mut batch = DBTransaction::new(&db);
-			try!(state_db.journal_under(&mut batch, 0, &spec.genesis_header().hash()));
+			state_db.journal_under(&mut batch, 0, &spec.genesis_header().hash())?;
-			try!(db.write(batch).map_err(ClientError::Database));
+			db.write(batch).map_err(ClientError::Database)?;
 		}
 
+		let gb = spec.genesis_block();
+		let chain = Arc::new(BlockChain::new(config.blockchain.clone(), &gb, db.clone(), spec.engine.clone()));
+		let tracedb = RwLock::new(TraceDB::new(config.tracing.clone(), db.clone(), chain.clone()));
+
 		trace!("Cleanup journal: DB Earliest = {:?}, Latest = {:?}", state_db.journal_db().earliest_era(), state_db.journal_db().latest_era());
 
 		let history = if config.history < MIN_HISTORY_SIZE {
@@ -203,8 +211,8 @@ impl Client {
 				for era in earliest..(latest - history + 1) {
 					trace!("Removing era {}", era);
 					let mut batch = DBTransaction::new(&db);
-					try!(state_db.mark_canonical(&mut batch, era, &chain.block_hash(era).expect("Old block not found in the database")));
+					state_db.mark_canonical(&mut batch, era, &chain.block_hash(era).expect("Old block not found in the database"))?;
-					try!(db.write(batch).map_err(ClientError::Database));
+					db.write(batch).map_err(ClientError::Database)?;
 				}
 			}
 		}
@@ -221,12 +229,6 @@ impl Client {
 
 		let awake = match config.mode { Mode::Dark(..) | Mode::Off => false, _ => true };
 
-		let factories = Factories {
-			vm: EvmFactory::new(config.vm_type.clone(), config.jump_table_size),
-			trie: trie_factory,
-			accountdb: Default::default(),
-		};
-
 		let client = Arc::new(Client {
 			enabled: AtomicBool::new(true),
 			sleep_state: Mutex::new(SleepState::new(awake)),
@@ -251,7 +253,7 @@ impl Client {
 			last_hashes: RwLock::new(VecDeque::new()),
 			factories: factories,
 			history: history,
-			rng: Mutex::new(try!(OsRng::new().map_err(::util::UtilError::StdIo))),
+			rng: Mutex::new(OsRng::new().map_err(::util::UtilError::StdIo)?),
 			on_mode_change: Mutex::new(None),
 			registrar: Mutex::new(None),
 		});
@@ -302,17 +304,16 @@ impl Client {
 
 	/// The env info as of the best block.
 	fn latest_env_info(&self) -> EnvInfo {
-		let header_data = self.best_block_header();
+		let header = self.best_block_header();
-		let view = HeaderView::new(&header_data);
 
 		EnvInfo {
-			number: view.number(),
+			number: header.number(),
-			author: view.author(),
+			author: header.author(),
-			timestamp: view.timestamp(),
+			timestamp: header.timestamp(),
-			difficulty: view.difficulty(),
+			difficulty: header.difficulty(),
-			last_hashes: self.build_last_hashes(view.hash()),
+			last_hashes: self.build_last_hashes(header.hash()),
 			gas_used: U256::default(),
-			gas_limit: view.gas_limit(),
+			gas_limit: header.gas_limit(),
 		}
 	}
 
@@ -369,9 +370,9 @@ impl Client {
 			let db = self.state_db.lock().boxed_clone_canon(header.parent_hash());
 
 			let enact_result = enact_verified(block, engine, self.tracedb.read().tracing_enabled(), db, &parent, last_hashes, self.factories.clone());
-			let locked_block = try!(enact_result.map_err(|e| {
+			let locked_block = enact_result.map_err(|e| {
 				warn!(target: "client", "Block import failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
-			}));
+			})?;
 
 			// Final Verification
 			if let Err(e) = self.verifier.verify_block_final(header, locked_block.block().header()) {
@@ -510,14 +511,14 @@ impl Client {
 			let chain = self.chain.read();
 
 			// verify block.
-			try!(::snapshot::verify_old_block(
+			::snapshot::verify_old_block(
 				&mut *rng,
 				&header,
 				&*self.engine,
 				&*chain,
 				Some(&block_bytes),
 				false,
-			));
+			)?;
 
 			// Commit results
 			let receipts = ::rlp::decode(&receipts_bytes);
@@ -618,7 +619,8 @@ impl Client {
 	/// Attempt to get a copy of a specific block's final state.
 	///
 	/// This will not fail if given BlockId::Latest.
-	/// Otherwise, this can fail (but may not) if the DB prunes state.
+	/// Otherwise, this can fail (but may not) if the DB prunes state or the block
+	/// is unknown.
 	pub fn state_at(&self, id: BlockId) -> Option<State> {
 		// fast path for latest state.
 		match id.clone() {
@@ -640,8 +642,7 @@ impl Client {
 				return None;
 			}
 
-			let root = HeaderView::new(&header).state_root();
+			let root = header.state_root();
-
 			State::from_existing(db, root, self.engine.account_start_nonce(), self.factories.clone()).ok()
 		})
 	}
@@ -664,7 +665,6 @@ impl Client {
 	/// Get a copy of the best block's state.
 	pub fn state(&self) -> State {
 		let header = self.best_block_header();
-		let header = HeaderView::new(&header);
 		State::from_existing(
 			self.state_db.lock().boxed_clone_canon(&header.hash()),
 			header.state_root(),
@@ -737,7 +737,7 @@ impl Client {
 	pub fn take_snapshot<W: snapshot_io::SnapshotWriter + Send>(&self, writer: W, at: BlockId, p: &snapshot::Progress) -> Result<(), EthcoreError> {
 		let db = self.state_db.lock().journal_db().boxed_clone();
 		let best_block_number = self.chain_info().best_block_number;
-		let block_number = try!(self.block_number(at).ok_or(snapshot::Error::InvalidStartingBlock(at)));
+		let block_number = self.block_number(at).ok_or(snapshot::Error::InvalidStartingBlock(at))?;
 
 		if best_block_number > self.history + block_number && db.is_pruned() {
 			return Err(snapshot::Error::OldBlockPrunedDB.into());
@@ -763,7 +763,7 @@ impl Client {
 			},
 		};
 
-		try!(snapshot::take_snapshot(&self.chain.read(), start_hash, db.as_hashdb(), writer, p));
+		snapshot::take_snapshot(&self.chain.read(), start_hash, db.as_hashdb(), writer, p)?;
 
 		Ok(())
 	}
@@ -827,7 +827,7 @@ impl snapshot::DatabaseRestore for Client {
 		let mut tracedb = self.tracedb.write();
 		self.miner.clear();
 		let db = self.db.write();
-		try!(db.restore(new_db));
+		db.restore(new_db)?;
 
 		let cache_size = state_db.cache_size();
 		*state_db = StateDB::new(journaldb::new(db.clone(), self.pruning, ::db::COL_STATE), cache_size);
@@ -840,26 +840,25 @@ impl snapshot::DatabaseRestore for Client {
 
 impl BlockChainClient for Client {
 	fn call(&self, t: &SignedTransaction, block: BlockId, analytics: CallAnalytics) -> Result<Executed, CallError> {
-		let header = try!(self.block_header(block).ok_or(CallError::StatePruned));
+		let header = self.block_header(block).ok_or(CallError::StatePruned)?;
-		let view = HeaderView::new(&header);
+		let last_hashes = self.build_last_hashes(header.parent_hash());
-		let last_hashes = self.build_last_hashes(view.parent_hash());
 		let env_info = EnvInfo {
-			number: view.number(),
+			number: header.number(),
-			author: view.author(),
+			author: header.author(),
-			timestamp: view.timestamp(),
+			timestamp: header.timestamp(),
-			difficulty: view.difficulty(),
+			difficulty: header.difficulty(),
 			last_hashes: last_hashes,
 			gas_used: U256::zero(),
 			gas_limit: U256::max_value(),
 		};
 		// that's just a copy of the state.
-		let mut state = try!(self.state_at(block).ok_or(CallError::StatePruned));
+		let mut state = self.state_at(block).ok_or(CallError::StatePruned)?;
 		let original_state = if analytics.state_diffing { Some(state.clone()) } else { None };
 
-		let sender = try!(t.sender().map_err(|e| {
+		let sender = t.sender().map_err(|e| {
 			let message = format!("Transaction malformed: {:?}", e);
 			ExecutionError::TransactionMalformed(message)
-		}));
+		})?;
 		let balance = state.balance(&sender);
 		let needed_balance = t.value + t.gas * t.gas_price;
 		if balance < needed_balance {
@@ -867,7 +866,7 @@ impl BlockChainClient for Client {
 			state.add_balance(&sender, &(needed_balance - balance), CleanupMode::NoEmpty);
 		}
 		let options = TransactOptions { tracing: analytics.transaction_tracing, vm_tracing: analytics.vm_tracing, check_nonce: false };
-		let mut ret = try!(Executive::new(&mut state, &env_info, &*self.engine, &self.factories.vm).transact(t, options));
+		let mut ret = Executive::new(&mut state, &env_info, &*self.engine, &self.factories.vm).transact(t, options)?;
 
 		// TODO gav move this into Executive.
 		ret.state_diff = original_state.map(|original| state.diff_from(original));
@@ -876,27 +875,26 @@ impl BlockChainClient for Client {
 	}
 
 	fn replay(&self, id: TransactionId, analytics: CallAnalytics) -> Result<Executed, CallError> {
-		let address = try!(self.transaction_address(id).ok_or(CallError::TransactionNotFound));
+		let address = self.transaction_address(id).ok_or(CallError::TransactionNotFound)?;
-		let header_data = try!(self.block_header(BlockId::Hash(address.block_hash)).ok_or(CallError::StatePruned));
+		let header = self.block_header(BlockId::Hash(address.block_hash)).ok_or(CallError::StatePruned)?;
-		let body_data = try!(self.block_body(BlockId::Hash(address.block_hash)).ok_or(CallError::StatePruned));
+		let body = self.block_body(BlockId::Hash(address.block_hash)).ok_or(CallError::StatePruned)?;
-		let mut state = try!(self.state_at_beginning(BlockId::Hash(address.block_hash)).ok_or(CallError::StatePruned));
+		let mut state = self.state_at_beginning(BlockId::Hash(address.block_hash)).ok_or(CallError::StatePruned)?;
-		let txs = BodyView::new(&body_data).transactions();
+		let txs = body.transactions();
 
 		if address.index >= txs.len() {
 			return Err(CallError::TransactionNotFound);
 		}
 
 		let options = TransactOptions { tracing: analytics.transaction_tracing, vm_tracing: analytics.vm_tracing, check_nonce: false };
-		let view = HeaderView::new(&header_data);
+		let last_hashes = self.build_last_hashes(header.hash());
-		let last_hashes = self.build_last_hashes(view.hash());
 		let mut env_info = EnvInfo {
-			number: view.number(),
+			number: header.number(),
-			author: view.author(),
+			author: header.author(),
-			timestamp: view.timestamp(),
+			timestamp: header.timestamp(),
-			difficulty: view.difficulty(),
+			difficulty: header.difficulty(),
 			last_hashes: last_hashes,
 			gas_used: U256::default(),
-			gas_limit: view.gas_limit(),
+			gas_limit: header.gas_limit(),
 		};
 		for t in txs.iter().take(address.index) {
 			match Executive::new(&mut state, &env_info, &*self.engine, &self.factories.vm).transact(t, Default::default()) {
@@ -907,7 +905,7 @@ impl BlockChainClient for Client {
 		let t = &txs[address.index];
 
 		let original_state = if analytics.state_diffing { Some(state.clone()) } else { None };
-		let mut ret = try!(Executive::new(&mut state, &env_info, &*self.engine, &self.factories.vm).transact(t, options));
+		let mut ret = Executive::new(&mut state, &env_info, &*self.engine, &self.factories.vm).transact(t, options)?;
 		ret.state_diff = original_state.map(|original| state.diff_from(original));
 
 		Ok(ret)
@@ -957,11 +955,11 @@ impl BlockChainClient for Client {
 		}
 	}
 
-	fn best_block_header(&self) -> Bytes {
+	fn best_block_header(&self) -> encoded::Header {
 		self.chain.read().best_block_header()
 	}
 
-	fn block_header(&self, id: BlockId) -> Option<Bytes> {
+	fn block_header(&self, id: BlockId) -> Option<::encoded::Header> {
 		let chain = self.chain.read();
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_header_data(&hash))
 	}
@@ -975,15 +973,15 @@ impl BlockChainClient for Client {
 		}
 	}
 
-	fn block_body(&self, id: BlockId) -> Option<Bytes> {
+	fn block_body(&self, id: BlockId) -> Option<encoded::Body> {
 		let chain = self.chain.read();
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_body(&hash))
 	}
 
-	fn block(&self, id: BlockId) -> Option<Bytes> {
+	fn block(&self, id: BlockId) -> Option<encoded::Block> {
 		if let BlockId::Pending = id {
 			if let Some(block) = self.miner.pending_block() {
-				return Some(block.rlp_bytes(Seal::Without));
+				return Some(encoded::Block::new(block.rlp_bytes(Seal::Without)));
 			}
 		}
 		let chain = self.chain.read();
@@ -1126,9 +1124,10 @@ impl BlockChainClient for Client {
 		self.transaction_address(id).map(|addr| addr.block_hash)
 	}
 
-	fn uncle(&self, id: UncleId) -> Option<Bytes> {
+	fn uncle(&self, id: UncleId) -> Option<encoded::Header> {
 		let index = id.position;
-		self.block_body(id.block).and_then(|body| BodyView::new(&body).uncle_rlp_at(index))
+		self.block_body(id.block).and_then(|body| body.view().uncle_rlp_at(index))
+			.map(encoded::Header::new)
 	}
 
 	fn transaction_receipt(&self, id: TransactionId) -> Option<LocalizedReceipt> {
@@ -1136,8 +1135,8 @@ impl BlockChainClient for Client {
 		self.transaction_address(id)
 			.and_then(|address| chain.block_number(&address.block_hash).and_then(|block_number| {
 			let t = chain.block_body(&address.block_hash)
-				.and_then(|block| {
+				.and_then(|body| {
-					BodyView::new(&block).localized_transaction_at(&address.block_hash, block_number, address.index)
+					body.view().localized_transaction_at(&address.block_hash, block_number, address.index)
 				});
 
 			let tx_and_sender = t.and_then(|tx| tx.sender().ok().map(|sender| (tx, sender)));
@@ -1205,7 +1204,7 @@ impl BlockChainClient for Client {
 	}
 
 	fn import_block(&self, bytes: Bytes) -> Result<H256, BlockImportError> {
-		use verification::queue::kind::HasHash;
+		use verification::queue::kind::BlockLike;
 		use verification::queue::kind::blocks::Unverified;
 
 		// create unverified block here so the `sha3` calculation can be cached.
@@ -1219,7 +1218,7 @@ impl BlockChainClient for Client {
 				return Err(BlockImportError::Block(BlockError::UnknownParent(unverified.parent_hash())));
 			}
 		}
-		Ok(try!(self.block_queue.import(unverified)))
+		Ok(self.block_queue.import(unverified)?)
 	}
 
 	fn import_block_with_receipts(&self, block_bytes: Bytes, receipts_bytes: Bytes) -> Result<H256, BlockImportError> {
@@ -1245,7 +1244,9 @@ impl BlockChainClient for Client {
 	}
 
 	fn chain_info(&self) -> BlockChainInfo {
-		self.chain.read().chain_info()
+		let mut chain_info = self.chain.read().chain_info();
+		chain_info.pending_total_difficulty = chain_info.total_difficulty + self.block_queue.total_difficulty();
+		chain_info
 	}
 
 	fn additional_params(&self) -> BTreeMap<String, String> {
@@ -1356,19 +1357,19 @@ impl BlockChainClient for Client {
 
 	fn block_extra_info(&self, id: BlockId) -> Option<BTreeMap<String, String>> {
 		self.block_header(id)
-			.map(|block| decode(&block))
+			.map(|header| self.engine.extra_info(&header.decode()))
-			.map(|header| self.engine.extra_info(&header))
 	}
 
 	fn uncle_extra_info(&self, id: UncleId) -> Option<BTreeMap<String, String>> {
 		self.uncle(id)
-			.map(|header| self.engine.extra_info(&decode(&header)))
+			.map(|header| self.engine.extra_info(&header.decode()))
 	}
 
 	fn pruning_info(&self) -> PruningInfo {
 		PruningInfo {
 			earliest_chain: self.chain.read().first_block_number().unwrap_or(1),
 			earliest_state: self.state_db.lock().journal_db().earliest_era().unwrap_or(0),
+			state_history_size: Some(self.history),
 		}
 	}
 

ethcore/src/client/registry.rs

@@ -43,7 +43,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":false,"inputs":[{"name":"_name","type":"bytes32"}],"name":"reserve","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"}`
@@ -55,7 +55,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"},{"name":"_value","type":"bytes32"}],"name":"set","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"}`
@@ -67,7 +67,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":false,"inputs":[{"name":"_name","type":"bytes32"}],"name":"drop","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"}`
@@ -79,7 +79,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"getAddress","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"}`
@@ -91,7 +91,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_address().ok_or("Invalid type returned")); util::Address::from(r) })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_address().ok_or("Invalid type returned")?; util::Address::from(r) })) 
 	}
 
 	/// Auto-generated from: `{"constant":false,"inputs":[{"name":"_amount","type":"uint256"}],"name":"setFee","outputs":[],"payable":false,"type":"function"}`
@@ -115,7 +115,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"}`
@@ -127,7 +127,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_address().ok_or("Invalid type returned")); util::Address::from(r) })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_address().ok_or("Invalid type returned")?; util::Address::from(r) })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[{"name":"_name","type":"bytes32"}],"name":"reserved","outputs":[{"name":"reserved","type":"bool"}],"payable":false,"type":"function"}`
@@ -139,7 +139,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":false,"inputs":[],"name":"drain","outputs":[],"payable":false,"type":"function"}`
@@ -163,7 +163,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"getUint","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"}`
@@ -175,7 +175,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_uint().ok_or("Invalid type returned")); util::U256::from(r.as_ref()) })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_uint().ok_or("Invalid type returned")?; util::U256::from(r.as_ref()) })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"get","outputs":[{"name":"","type":"bytes32"}],"payable":false,"type":"function"}`
@@ -187,7 +187,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_fixed_bytes().ok_or("Invalid type returned")); util::H256::from_slice(r.as_ref()) })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_fixed_bytes().ok_or("Invalid type returned")?; util::H256::from_slice(r.as_ref()) })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[],"name":"fee","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"}`
@@ -199,7 +199,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_uint().ok_or("Invalid type returned")); util::U256::from(r.as_ref()) })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_uint().ok_or("Invalid type returned")?; util::U256::from(r.as_ref()) })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[{"name":"_name","type":"bytes32"}],"name":"getOwner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"}`
@@ -211,7 +211,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_address().ok_or("Invalid type returned")); util::Address::from(r) })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_address().ok_or("Invalid type returned")?; util::Address::from(r) })) 
 	}
 
 	/// Auto-generated from: `{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"reverse","outputs":[{"name":"","type":"string"}],"payable":false,"type":"function"}`
@@ -223,7 +223,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_string().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_string().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"},{"name":"_value","type":"uint256"}],"name":"setUint","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"}`
@@ -235,7 +235,7 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 
 	/// Auto-generated from: `{"constant":false,"inputs":[],"name":"removeReverse","outputs":[],"payable":false,"type":"function"}`
@@ -259,6 +259,6 @@ impl Registry {
 		).map_err(Self::as_string)?;
 		let output = call.decode_output((self.do_call)(self.address.clone(), data)?).map_err(Self::as_string)?;
 		let mut result = output.into_iter().rev().collect::<Vec<_>>();
-		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = try!(r.to_bool().ok_or("Invalid type returned")); r })) 
+		Ok(({ let r = result.pop().ok_or("Invalid return arity")?; let r = r.to_bool().ok_or("Invalid type returned")?; r })) 
 	}
 }

ethcore/src/client/test_client.rs

@@ -39,7 +39,6 @@ use miner::{Miner, MinerService, TransactionImportResult};
 use spec::Spec;
 use types::mode::Mode;
 use types::pruning_info::PruningInfo;
-use views::BlockView;
 
 use verification::queue::QueueInfo;
 use block::{OpenBlock, SealedBlock};
@@ -47,6 +46,7 @@ use executive::Executed;
 use error::CallError;
 use trace::LocalizedTrace;
 use state_db::StateDB;
+use encoded;
 
 /// Test client.
 pub struct TestBlockChainClient {
@@ -92,6 +92,8 @@ pub struct TestBlockChainClient {
 	pub first_block: RwLock<Option<(H256, u64)>>,
 	/// Traces to return
 	pub traces: RwLock<Option<Vec<LocalizedTrace>>>,
+	/// Pruning history size to report.
+	pub history: RwLock<Option<u64>>,
 }
 
 /// Used for generating test client blocks.
@@ -154,6 +156,7 @@ impl TestBlockChainClient {
 			ancient_block: RwLock::new(None),
 			first_block: RwLock::new(None),
 			traces: RwLock::new(None),
+			history: RwLock::new(None),
 		};
 		client.add_blocks(1, EachBlockWith::Nothing); // add genesis block
 		client.genesis_hash = client.last_hash.read().clone();
@@ -260,7 +263,7 @@ impl TestBlockChainClient {
 	/// Make a bad block by setting invalid extra data.
 	pub fn corrupt_block(&self, n: BlockNumber) {
 		let hash = self.block_hash(BlockId::Number(n)).unwrap();
-		let mut header: BlockHeader = decode(&self.block_header(BlockId::Number(n)).unwrap());
+		let mut header: BlockHeader = self.block_header(BlockId::Number(n)).unwrap().decode();
 		header.set_extra_data(b"This extra data is way too long to be considered valid".to_vec());
 		let mut rlp = RlpStream::new_list(3);
 		rlp.append(&header);
@@ -272,7 +275,7 @@ impl TestBlockChainClient {
 	/// Make a bad block by setting invalid parent hash.
 	pub fn corrupt_block_parent(&self, n: BlockNumber) {
 		let hash = self.block_hash(BlockId::Number(n)).unwrap();
-		let mut header: BlockHeader = decode(&self.block_header(BlockId::Number(n)).unwrap());
+		let mut header: BlockHeader = self.block_header(BlockId::Number(n)).unwrap().decode();
 		header.set_parent_hash(H256::from(42));
 		let mut rlp = RlpStream::new_list(3);
 		rlp.append(&header);
@@ -314,6 +317,11 @@ impl TestBlockChainClient {
 		let res = res.into_iter().next().unwrap().expect("Successful import");
 		assert_eq!(res, TransactionImportResult::Current);
 	}
+
+	/// Set reported history size.
+	pub fn set_history(&self, h: Option<u64>) {
+		*self.history.write() = h;
+	}
 }
 
 pub fn get_temp_state_db() -> GuardedTempResult<StateDB> {
@@ -336,8 +344,7 @@ impl MiningBlockChainClient for TestBlockChainClient {
 		let engine = &*self.spec.engine;
 		let genesis_header = self.spec.genesis_header();
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = self.spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		self.spec.ensure_db_good(&mut db, &TrieFactory::default()).unwrap();
 
 		let last_hashes = vec![genesis_header.hash()];
 		let mut open_block = OpenBlock::new(
@@ -451,7 +458,7 @@ impl BlockChainClient for TestBlockChainClient {
 		None	// Simple default.
 	}
 
-	fn uncle(&self, _id: UncleId) -> Option<Bytes> {
+	fn uncle(&self, _id: UncleId) -> Option<encoded::Header> {
 		None	// Simple default.
 	}
 
@@ -480,34 +487,39 @@ impl BlockChainClient for TestBlockChainClient {
 		unimplemented!();
 	}
 
-	fn best_block_header(&self) -> Bytes {
+	fn best_block_header(&self) -> encoded::Header {
-		self.block_header(BlockId::Hash(self.chain_info().best_block_hash)).expect("Best block always have header.")
+		self.block_header(BlockId::Hash(self.chain_info().best_block_hash))
+			.expect("Best block always has header.")
 	}
 
-	fn block_header(&self, id: BlockId) -> Option<Bytes> {
+	fn block_header(&self, id: BlockId) -> Option<encoded::Header> {
-		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).map(|r| Rlp::new(r).at(0).as_raw().to_vec()))
+		self.block_hash(id)
+			.and_then(|hash| self.blocks.read().get(&hash).map(|r| Rlp::new(r).at(0).as_raw().to_vec()))
+			.map(encoded::Header::new)
 	}
 
 	fn block_number(&self, _id: BlockId) -> Option<BlockNumber> {
 		unimplemented!()
 	}
 
-	fn block_body(&self, id: BlockId) -> Option<Bytes> {
+	fn block_body(&self, id: BlockId) -> Option<encoded::Body> {
 		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).map(|r| {
 			let mut stream = RlpStream::new_list(2);
 			stream.append_raw(Rlp::new(r).at(1).as_raw(), 1);
 			stream.append_raw(Rlp::new(r).at(2).as_raw(), 1);
-			stream.out()
+			encoded::Body::new(stream.out())
 		}))
 	}
 
-	fn block(&self, id: BlockId) -> Option<Bytes> {
+	fn block(&self, id: BlockId) -> Option<encoded::Block> {
-		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).cloned())
+		self.block_hash(id)
+			.and_then(|hash| self.blocks.read().get(&hash).cloned())
+			.map(encoded::Block::new)
 	}
 
 	fn block_extra_info(&self, id: BlockId) -> Option<BTreeMap<String, String>> {
 		self.block(id)
-			.map(|block| BlockView::new(&block).header())
+			.map(|block| block.view().header())
 			.map(|header| self.spec.engine.extra_info(&header))
 	}
 
@@ -516,7 +528,8 @@ impl BlockChainClient for TestBlockChainClient {
 		match id {
 			BlockId::Number(number) if (number as usize) < self.blocks.read().len() => BlockStatus::InChain,
 			BlockId::Hash(ref hash) if self.blocks.read().get(hash).is_some() => BlockStatus::InChain,
-			_ => BlockStatus::Unknown
+			BlockId::Latest | BlockId::Pending | BlockId::Earliest => BlockStatus::InChain,
+			_ => BlockStatus::Unknown,
 		}
 	}
 
@@ -704,6 +717,7 @@ impl BlockChainClient for TestBlockChainClient {
 		PruningInfo {
 			earliest_chain: 1,
 			earliest_state: 1,
+			state_history_size: *self.history.read(),
 		}
 	}
 

ethcore/src/client/traits.rs

@@ -24,7 +24,6 @@ use header::{BlockNumber};
 use transaction::{LocalizedTransaction, SignedTransaction, PendingTransaction};
 use log_entry::LocalizedLogEntry;
 use filter::Filter;
-use views::{BlockView};
 use error::{ImportResult, CallError};
 use receipt::LocalizedReceipt;
 use trace::LocalizedTrace;
@@ -40,6 +39,7 @@ use types::blockchain_info::BlockChainInfo;
 use types::block_status::BlockStatus;
 use types::mode::Mode;
 use types::pruning_info::PruningInfo;
+use encoded;
 
 #[ipc(client_ident="RemoteClient")]
 /// Blockchain database client. Owns and manages a blockchain and a block queue.
@@ -50,17 +50,17 @@ pub trait BlockChainClient : Sync + Send {
 	fn keep_alive(&self) {}
 
 	/// Get raw block header data by block id.
-	fn block_header(&self, id: BlockId) -> Option<Bytes>;
+	fn block_header(&self, id: BlockId) -> Option<encoded::Header>;
 
 	/// Look up the block number for the given block ID.
 	fn block_number(&self, id: BlockId) -> Option<BlockNumber>;
 
 	/// Get raw block body data by block id.
 	/// Block body is an RLP list of two items: uncles and transactions.
-	fn block_body(&self, id: BlockId) -> Option<Bytes>;
+	fn block_body(&self, id: BlockId) -> Option<encoded::Body>;
 
 	/// Get raw block data by block header hash.
-	fn block(&self, id: BlockId) -> Option<Bytes>;
+	fn block(&self, id: BlockId) -> Option<encoded::Block>;
 
 	/// Get block status by block header hash.
 	fn block_status(&self, id: BlockId) -> BlockStatus;
@@ -136,7 +136,7 @@ pub trait BlockChainClient : Sync + Send {
 	fn transaction_block(&self, id: TransactionId) -> Option<H256>;
 
 	/// Get uncle with given id.
-	fn uncle(&self, id: UncleId) -> Option<Bytes>;
+	fn uncle(&self, id: UncleId) -> Option<encoded::Header>;
 
 	/// Get transaction receipt with given hash.
 	fn transaction_receipt(&self, id: TransactionId) -> Option<LocalizedReceipt>;
@@ -173,7 +173,7 @@ pub trait BlockChainClient : Sync + Send {
 	fn additional_params(&self) -> BTreeMap<String, String>;
 
 	/// Get the best block header.
-	fn best_block_header(&self) -> Bytes;
+	fn best_block_header(&self) -> encoded::Header;
 
 	/// Returns numbers of blocks containing given bloom.
 	fn blocks_with_bloom(&self, bloom: &H2048, from_block: BlockId, to_block: BlockId) -> Option<Vec<BlockNumber>>;
@@ -220,8 +220,7 @@ pub trait BlockChainClient : Sync + Send {
 		let mut corpus = Vec::new();
 		while corpus.is_empty() {
 			for _ in 0..sample_size {
-				let block_bytes = self.block(BlockId::Hash(h)).expect("h is either the best_block_hash or an ancestor; qed");
+				let block = self.block(BlockId::Hash(h)).expect("h is either the best_block_hash or an ancestor; qed");
-				let block = BlockView::new(&block_bytes);
 				let header = block.header_view();
 				if header.number() == 0 {
 					return corpus;

ethcore/src/engines/authority_round.rs

@@ -107,7 +107,7 @@ impl AuthorityRound {
 				params: params,
 				our_params: our_params,
 				builtins: builtins,
-				transition_service: try!(IoService::<()>::start()),
+				transition_service: IoService::<()>::start()?,
 				message_channel: Mutex::new(None),
 				step: AtomicUsize::new(initial_step),
 				proposed: AtomicBool::new(false),
@@ -117,7 +117,7 @@ impl AuthorityRound {
 		// Do not initialize timeouts for tests.
 		if should_timeout {
 			let handler = TransitionHandler { engine: Arc::downgrade(&engine) };
-			try!(engine.transition_service.register_handler(Arc::new(handler)));
+			engine.transition_service.register_handler(Arc::new(handler))?;
 		}
 		Ok(engine)
 	}
@@ -263,20 +263,20 @@ impl Engine for AuthorityRound {
 
 	/// Check if the signature belongs to the correct proposer.
 	fn verify_block_unordered(&self, header: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
-		let header_step = try!(header_step(header));
+		let header_step = header_step(header)?;
 		// Give one step slack if step is lagging, double vote is still not possible.
 		if header_step <= self.step.load(AtomicOrdering::SeqCst) + 1 {
-			let proposer_signature = try!(header_signature(header));
+			let proposer_signature = header_signature(header)?;
-			let ok_sig = try!(verify_address(self.step_proposer(header_step), &proposer_signature, &header.bare_hash()));
+			let ok_sig = verify_address(self.step_proposer(header_step), &proposer_signature, &header.bare_hash())?;
 			if ok_sig {
 				Ok(())
 			} else {
 				trace!(target: "poa", "verify_block_unordered: invalid seal signature");
-				try!(Err(BlockError::InvalidSeal))
+				Err(BlockError::InvalidSeal)?
 			}
 		} else {
 			trace!(target: "poa", "verify_block_unordered: block from the future");
-			try!(Err(BlockError::InvalidSeal))
+			Err(BlockError::InvalidSeal)?
 		}
 	}
 
@@ -285,11 +285,11 @@ impl Engine for AuthorityRound {
 			return Err(From::from(BlockError::RidiculousNumber(OutOfBounds { min: Some(1), max: None, found: header.number() })));
 		}
 
-		let step = try!(header_step(header));
+		let step = header_step(header)?;
 		// Check if parent is from a previous step.
-		if step == try!(header_step(parent)) {
+		if step == header_step(parent)? {
 			trace!(target: "poa", "Multiple blocks proposed for step {}.", step);
-			try!(Err(EngineError::DoubleVote(header.author().clone())));
+			Err(EngineError::DoubleVote(header.author().clone()))?;
 		}
 
 		let gas_limit_divisor = self.our_params.gas_limit_bound_divisor;
@@ -302,7 +302,7 @@ impl Engine for AuthorityRound {
 	}
 
 	fn verify_transaction_basic(&self, t: &SignedTransaction, _header: &Header) -> Result<(), Error> {
-		try!(t.check_low_s());
+		t.check_low_s()?;
 		Ok(())
 	}
 
@@ -339,7 +339,6 @@ impl Engine for AuthorityRound {
 #[cfg(test)]
 mod tests {
 	use util::*;
-	use util::trie::TrieSpec;
 	use env_info::EnvInfo;
 	use header::Header;
 	use error::{Error, BlockError};
@@ -407,10 +406,8 @@ mod tests {
 		let engine = &*spec.engine;
 		engine.register_account_provider(Arc::new(tap));
 		let genesis_header = spec.genesis_header();
-		let mut db1 = get_temp_state_db().take();
+		let db1 = spec.ensure_db_good(get_temp_state_db().take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db1, &TrieFactory::new(TrieSpec::Secure)).unwrap();
+		let db2 = spec.ensure_db_good(get_temp_state_db().take(), &Default::default()).unwrap();
-		let mut db2 = get_temp_state_db().take();
-		spec.ensure_db_good(&mut db2, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b1 = OpenBlock::new(engine, Default::default(), false, db1, &genesis_header, last_hashes.clone(), addr1, (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b1 = b1.close_and_lock();

ethcore/src/engines/basic_authority.rs

@@ -143,10 +143,10 @@ impl Engine for BasicAuthority {
 		use rlp::{UntrustedRlp, View};
 
 		// check the signature is legit.
-		let sig = try!(UntrustedRlp::new(&header.seal()[0]).as_val::<H520>());
+		let sig = UntrustedRlp::new(&header.seal()[0]).as_val::<H520>()?;
-		let signer = public_to_address(&try!(recover(&sig.into(), &header.bare_hash())));
+		let signer = public_to_address(&recover(&sig.into(), &header.bare_hash())?);
 		if !self.our_params.authorities.contains(&signer) {
-			return try!(Err(BlockError::InvalidSeal));
+			return Err(BlockError::InvalidSeal)?;
 		}
 		Ok(())
 	}
@@ -171,7 +171,7 @@ impl Engine for BasicAuthority {
 	}
 
 	fn verify_transaction_basic(&self, t: &SignedTransaction, _header: &Header) -> result::Result<(), Error> {
-		try!(t.check_low_s());
+		t.check_low_s()?;
 		Ok(())
 	}
 
@@ -191,7 +191,6 @@ impl Engine for BasicAuthority {
 #[cfg(test)]
 mod tests {
 	use util::*;
-	use util::trie::TrieSpec;
 	use block::*;
 	use env_info::EnvInfo;
 	use error::{BlockError, Error};
@@ -265,8 +264,7 @@ mod tests {
 		engine.register_account_provider(Arc::new(tap));
 		let genesis_header = spec.genesis_header();
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes, addr, (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b = b.close_and_lock();

ethcore/src/engines/instant_seal.rs

@@ -66,7 +66,6 @@ impl Engine for InstantSeal {
 #[cfg(test)]
 mod tests {
 	use util::*;
-	use util::trie::TrieSpec;
 	use tests::helpers::*;
 	use spec::Spec;
 	use header::Header;
@@ -79,8 +78,7 @@ mod tests {
 		let engine = &*spec.engine;
 		let genesis_header = spec.genesis_header();
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes, Address::default(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b = b.close_and_lock();

ethcore/src/engines/tendermint/message.rs

@@ -51,9 +51,9 @@ impl ConsensusMessage {
 
 	pub fn new_proposal(header: &Header) -> Result<Self, ::rlp::DecoderError> {
 		Ok(ConsensusMessage {
-			signature: try!(UntrustedRlp::new(header.seal().get(1).expect("seal passed basic verification; seal has 3 fields; qed").as_slice()).as_val()),
+			signature: UntrustedRlp::new(header.seal().get(1).expect("seal passed basic verification; seal has 3 fields; qed").as_slice()).as_val()?,
 			height: header.number() as Height,
-			round: try!(consensus_round(header)),
+			round: consensus_round(header)?,
 			step: Step::Propose,
 			block_hash: Some(header.bare_hash()),
 		})
@@ -92,7 +92,7 @@ impl ConsensusMessage {
 	pub fn verify(&self) -> Result<Address, Error> {
 		let full_rlp = ::rlp::encode(self);
 		let block_info = Rlp::new(&full_rlp).at(1);
-		let public_key = try!(recover(&self.signature.into(), &block_info.as_raw().sha3()));
+		let public_key = recover(&self.signature.into(), &block_info.as_raw().sha3())?;
 		Ok(public_to_address(&public_key))
 	}
 
@@ -134,7 +134,7 @@ impl Ord for ConsensusMessage {
 
 impl Decodable for Step {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		match try!(decoder.as_rlp().as_val()) {
+		match decoder.as_rlp().as_val()? {
 			0u8 => Ok(Step::Propose),
 			1 => Ok(Step::Prevote),
 			2 => Ok(Step::Precommit),
@@ -153,13 +153,13 @@ impl Encodable for Step {
 impl Decodable for ConsensusMessage {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let rlp = decoder.as_rlp();
-		let m = try!(rlp.at(1));
+		let m = rlp.at(1)?;
-		let block_message: H256 = try!(m.val_at(3));
+		let block_message: H256 = m.val_at(3)?;
 		Ok(ConsensusMessage {
-			signature: try!(rlp.val_at(0)),
+			signature: rlp.val_at(0)?,
-			height: try!(m.val_at(0)),
+			height: m.val_at(0)?,
-			round: try!(m.val_at(1)),
+			round: m.val_at(1)?,
-			step: try!(m.val_at(2)),
+			step: m.val_at(2)?,
 			block_hash: match block_message.is_zero() {
 				true => None,
 				false => Some(block_message),

ethcore/src/engines/tendermint/mod.rs

@@ -109,7 +109,7 @@ impl Tendermint {
 				params: params,
 				our_params: our_params,
 				builtins: builtins,
-				step_service: try!(IoService::<Step>::start()),
+				step_service: IoService::<Step>::start()?,
 				authority: RwLock::new(Address::default()),
 				password: RwLock::new(None),
 				height: AtomicUsize::new(1),
@@ -123,7 +123,7 @@ impl Tendermint {
 				proposal: RwLock::new(None),
 			});
 		let handler = TransitionHandler { engine: Arc::downgrade(&engine) };
-		try!(engine.step_service.register_handler(Arc::new(handler)));
+		engine.step_service.register_handler(Arc::new(handler))?;
 		Ok(engine)
 	}
 
@@ -455,11 +455,11 @@ impl Engine for Tendermint {
 
 	fn handle_message(&self, rlp: &[u8]) -> Result<(), Error> {
 		let rlp = UntrustedRlp::new(rlp);
-		let message: ConsensusMessage = try!(rlp.as_val());
+		let message: ConsensusMessage = rlp.as_val()?;
 		if !self.votes.is_old_or_known(&message) {
-			let sender = public_to_address(&try!(recover(&message.signature.into(), &try!(rlp.at(1)).as_raw().sha3())));
+			let sender = public_to_address(&recover(&message.signature.into(), &rlp.at(1)?.as_raw().sha3())?);
 			if !self.is_authority(&sender) {
-				try!(Err(EngineError::NotAuthorized(sender)));
+				Err(EngineError::NotAuthorized(sender))?;
 			}
 			self.broadcast_message(rlp.as_raw().to_vec());
 			trace!(target: "poa", "Handling a valid {:?} from {}.", message, sender);
@@ -491,10 +491,10 @@ impl Engine for Tendermint {
 	}
 
 	fn verify_block_unordered(&self, header: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
-		let proposal = try!(ConsensusMessage::new_proposal(header));	
+		let proposal = ConsensusMessage::new_proposal(header)?;	
-		let proposer = try!(proposal.verify());
+		let proposer = proposal.verify()?;
 		if !self.is_authority(&proposer) {
-			try!(Err(EngineError::NotAuthorized(proposer)))
+			Err(EngineError::NotAuthorized(proposer))?
 		}
 
 		let precommit_hash = proposal.precommit_hash();
@@ -502,20 +502,20 @@ impl Engine for Tendermint {
 		let mut signature_count = 0;
 		let mut origins = HashSet::new();
 		for rlp in UntrustedRlp::new(signatures_field).iter() {
-			let precommit: ConsensusMessage = ConsensusMessage::new_commit(&proposal, try!(rlp.as_val()));
+			let precommit: ConsensusMessage = ConsensusMessage::new_commit(&proposal, rlp.as_val()?);
 			let address = match self.votes.get(&precommit) {
 				Some(a) => a,
-				None => public_to_address(&try!(recover(&precommit.signature.into(), &precommit_hash))),
+				None => public_to_address(&recover(&precommit.signature.into(), &precommit_hash)?),
 			};
 			if !self.our_params.authorities.contains(&address) {
-				try!(Err(EngineError::NotAuthorized(address.to_owned())))
+				Err(EngineError::NotAuthorized(address.to_owned()))?
 			}
 
 			if origins.insert(address) {
 				signature_count += 1;
 			} else {
 				warn!(target: "poa", "verify_block_unordered: Duplicate signature from {} on the seal.", address);
-				try!(Err(BlockError::InvalidSeal));
+				Err(BlockError::InvalidSeal)?;
 			}
 		}
 
@@ -524,34 +524,34 @@ impl Engine for Tendermint {
 			let signatures_len = signatures_field.len();
 			// Proposal has to have an empty signature list.
 			if signatures_len != 1 {
-				try!(Err(EngineError::BadSealFieldSize(OutOfBounds {
+				Err(EngineError::BadSealFieldSize(OutOfBounds {
 					min: Some(1),
 					max: Some(1),
 					found: signatures_len
-				})));
+				}))?;
 			}
-			try!(self.is_round_proposer(proposal.height, proposal.round, &proposer));
+			self.is_round_proposer(proposal.height, proposal.round, &proposer)?;
 		}
 		Ok(())
 	}
 
 	fn verify_block_family(&self, header: &Header, parent: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
 		if header.number() == 0 {
-			try!(Err(BlockError::RidiculousNumber(OutOfBounds { min: Some(1), max: None, found: header.number() })));
+			Err(BlockError::RidiculousNumber(OutOfBounds { min: Some(1), max: None, found: header.number() }))?;
 		}
 
 		let gas_limit_divisor = self.our_params.gas_limit_bound_divisor;
 		let min_gas = parent.gas_limit().clone() - parent.gas_limit().clone() / gas_limit_divisor;
 		let max_gas = parent.gas_limit().clone() + parent.gas_limit().clone() / gas_limit_divisor;
 		if header.gas_limit() <= &min_gas || header.gas_limit() >= &max_gas {
-			try!(Err(BlockError::InvalidGasLimit(OutOfBounds { min: Some(min_gas), max: Some(max_gas), found: header.gas_limit().clone() })));
+			Err(BlockError::InvalidGasLimit(OutOfBounds { min: Some(min_gas), max: Some(max_gas), found: header.gas_limit().clone() }))?;
 		}
 
 		Ok(())
 	}
 
 	fn verify_transaction_basic(&self, t: &SignedTransaction, _header: &Header) -> Result<(), Error> {
-		try!(t.check_low_s());
+		t.check_low_s()?;
 		Ok(())
 	}
 
@@ -656,7 +656,6 @@ impl Engine for Tendermint {
 #[cfg(test)]
 mod tests {
 	use util::*;
-	use util::trie::TrieSpec;
 	use io::{IoContext, IoHandler};
 	use block::*;
 	use error::{Error, BlockError};
@@ -681,8 +680,7 @@ mod tests {
 
 	fn propose_default(spec: &Spec, proposer: Address) -> (LockedBlock, Vec<Bytes>) {
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let genesis_header = spec.genesis_header();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(spec.engine.as_ref(), Default::default(), false, db.boxed_clone(), &genesis_header, last_hashes, proposer, (3141562.into(), 31415620.into()), vec![]).unwrap();
@@ -889,9 +887,6 @@ mod tests {
 	fn relays_messages() {
 		let (spec, tap) = setup();
 		let engine = spec.engine.clone();
-		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		
 		let v0 = insert_and_register(&tap, &engine, "0");
 		let v1 = insert_and_register(&tap, &engine, "1");
@@ -925,9 +920,6 @@ mod tests {
 	fn seal_submission() {
 		let (spec, tap) = setup();
 		let engine = spec.engine.clone();
-		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		
 		let v0 = insert_and_register(&tap, &engine, "0");
 		let v1 = insert_and_register(&tap, &engine, "1");

ethcore/src/ethereum/ethash.rs

@@ -240,8 +240,8 @@ impl Engine for Ethash {
 				Mismatch { expected: self.seal_fields(), found: header.seal().len() }
 			)));
 		}
-		try!(UntrustedRlp::new(&header.seal()[0]).as_val::<H256>());
+		UntrustedRlp::new(&header.seal()[0]).as_val::<H256>()?;
-		try!(UntrustedRlp::new(&header.seal()[1]).as_val::<H64>());
+		UntrustedRlp::new(&header.seal()[1]).as_val::<H64>()?;
 
 		// TODO: consider removing these lines.
 		let min_difficulty = self.ethash_params.minimum_difficulty;
@@ -312,7 +312,7 @@ impl Engine for Ethash {
 
 	fn verify_transaction_basic(&self, t: &SignedTransaction, header: &Header) -> result::Result<(), Error> {
 		if header.number() >= self.ethash_params.homestead_transition {
-			try!(t.check_low_s());
+			t.check_low_s()?;
 		}
 
 		if let Some(n) = t.network_id() {
@@ -433,7 +433,6 @@ impl Header {
 #[cfg(test)]
 mod tests {
 	use util::*;
-	use util::trie::TrieSpec;
 	use block::*;
 	use tests::helpers::*;
 	use env_info::EnvInfo;
@@ -449,8 +448,7 @@ mod tests {
 		let engine = &*spec.engine;
 		let genesis_header = spec.genesis_header();
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes, Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b = b.close();
@@ -463,8 +461,7 @@ mod tests {
 		let engine = &*spec.engine;
 		let genesis_header = spec.genesis_header();
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let mut b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes, Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let mut uncle = Header::new();

ethcore/src/ethereum/mod.rs

@@ -78,7 +78,6 @@ pub fn new_morden() -> Spec { load(include_bytes!("../../res/ethereum/morden.jso
 #[cfg(test)]
 mod tests {
 	use util::*;
-	use util::trie::TrieSpec;
 	use state::*;
 	use super::*;
 	use tests::helpers::*;
@@ -90,8 +89,7 @@ mod tests {
 		let engine = &spec.engine;
 		let genesis_header = spec.genesis_header();
 		let mut db_result = get_temp_state_db();
-		let mut db = db_result.take();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-		spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 		let s = State::from_existing(db, genesis_header.state_root().clone(), engine.account_start_nonce(), Default::default()).unwrap();
 		assert_eq!(s.balance(&"0000000000000000000000000000000000000001".into()), 1u64.into());
 		assert_eq!(s.balance(&"0000000000000000000000000000000000000002".into()), 1u64.into());

ethcore/src/evm/interpreter/gasometer.rs

@@ -159,39 +159,39 @@ impl<Gas: CostType> Gasometer<Gas> {
 				Request::Gas(gas)
 			},
 			instructions::MSTORE | instructions::MLOAD => {
-				Request::GasMem(default_gas, try!(mem_needed_const(stack.peek(0), 32)))
+				Request::GasMem(default_gas, mem_needed_const(stack.peek(0), 32)?)
 			},
 			instructions::MSTORE8 => {
-				Request::GasMem(default_gas, try!(mem_needed_const(stack.peek(0), 1)))
+				Request::GasMem(default_gas, mem_needed_const(stack.peek(0), 1)?)
 			},
 			instructions::RETURN => {
-				Request::GasMem(default_gas, try!(mem_needed(stack.peek(0), stack.peek(1))))
+				Request::GasMem(default_gas, mem_needed(stack.peek(0), stack.peek(1))?)
 			},
 			instructions::SHA3 => {
-				let w = overflowing!(add_gas_usize(try!(Gas::from_u256(*stack.peek(1))), 31));
+				let w = overflowing!(add_gas_usize(Gas::from_u256(*stack.peek(1))?, 31));
 				let words = w >> 5;
 				let gas = Gas::from(schedule.sha3_gas) + (Gas::from(schedule.sha3_word_gas) * words);
-				Request::GasMem(gas, try!(mem_needed(stack.peek(0), stack.peek(1))))
+				Request::GasMem(gas, mem_needed(stack.peek(0), stack.peek(1))?)
 			},
 			instructions::CALLDATACOPY | instructions::CODECOPY => {
-				Request::GasMemCopy(default_gas, try!(mem_needed(stack.peek(0), stack.peek(2))), try!(Gas::from_u256(*stack.peek(2))))
+				Request::GasMemCopy(default_gas, mem_needed(stack.peek(0), stack.peek(2))?, Gas::from_u256(*stack.peek(2))?)
 			},
 			instructions::EXTCODECOPY => {
-				Request::GasMemCopy(schedule.extcodecopy_base_gas.into(), try!(mem_needed(stack.peek(1), stack.peek(3))), try!(Gas::from_u256(*stack.peek(3))))
+				Request::GasMemCopy(schedule.extcodecopy_base_gas.into(), mem_needed(stack.peek(1), stack.peek(3))?, Gas::from_u256(*stack.peek(3))?)
 			},
 			instructions::LOG0...instructions::LOG4 => {
 				let no_of_topics = instructions::get_log_topics(instruction);
 				let log_gas = schedule.log_gas + schedule.log_topic_gas * no_of_topics;
 
-				let data_gas = overflowing!(try!(Gas::from_u256(*stack.peek(1))).overflow_mul(Gas::from(schedule.log_data_gas)));
+				let data_gas = overflowing!(Gas::from_u256(*stack.peek(1))?.overflow_mul(Gas::from(schedule.log_data_gas)));
 				let gas = overflowing!(data_gas.overflow_add(Gas::from(log_gas)));
-				Request::GasMem(gas, try!(mem_needed(stack.peek(0), stack.peek(1))))
+				Request::GasMem(gas, mem_needed(stack.peek(0), stack.peek(1))?)
 			},
 			instructions::CALL | instructions::CALLCODE => {
 				let mut gas = Gas::from(schedule.call_gas);
 				let mem = cmp::max(
-					try!(mem_needed(stack.peek(5), stack.peek(6))),
+					mem_needed(stack.peek(5), stack.peek(6))?,
-					try!(mem_needed(stack.peek(3), stack.peek(4)))
+					mem_needed(stack.peek(3), stack.peek(4))?
 				);
 
 				let address = u256_to_address(stack.peek(1));
@@ -216,8 +216,8 @@ impl<Gas: CostType> Gasometer<Gas> {
 			instructions::DELEGATECALL => {
 				let gas = Gas::from(schedule.call_gas);
 				let mem = cmp::max(
-					try!(mem_needed(stack.peek(4), stack.peek(5))),
+					mem_needed(stack.peek(4), stack.peek(5))?,
-					try!(mem_needed(stack.peek(2), stack.peek(3)))
+					mem_needed(stack.peek(2), stack.peek(3))?
 				);
 				let requested = *stack.peek(0);
 
@@ -225,7 +225,7 @@ impl<Gas: CostType> Gasometer<Gas> {
 			},
 			instructions::CREATE => {
 				let gas = Gas::from(schedule.create_gas);
-				let mem = try!(mem_needed(stack.peek(1), stack.peek(2)));
+				let mem = mem_needed(stack.peek(1), stack.peek(2))?;
 
 				Request::GasMemProvide(gas, mem, None)
 			},
@@ -248,7 +248,7 @@ impl<Gas: CostType> Gasometer<Gas> {
 				}
 			},
 			Request::GasMem(gas, mem_size) => {
-				let (mem_gas_cost, new_mem_gas, new_mem_size) = try!(self.mem_gas_cost(schedule, current_mem_size, &mem_size));
+				let (mem_gas_cost, new_mem_gas, new_mem_size) = self.mem_gas_cost(schedule, current_mem_size, &mem_size)?;
 				let gas = overflowing!(gas.overflow_add(mem_gas_cost));
 				InstructionRequirements {
 					gas_cost: gas,
@@ -258,9 +258,9 @@ impl<Gas: CostType> Gasometer<Gas> {
 				}
 			},
 			Request::GasMemProvide(gas, mem_size, requested) => {
-				let (mem_gas_cost, new_mem_gas, new_mem_size) = try!(self.mem_gas_cost(schedule, current_mem_size, &mem_size));
+				let (mem_gas_cost, new_mem_gas, new_mem_size) = self.mem_gas_cost(schedule, current_mem_size, &mem_size)?;
 				let gas = overflowing!(gas.overflow_add(mem_gas_cost));
-				let provided = try!(self.gas_provided(schedule, gas, requested));
+				let provided = self.gas_provided(schedule, gas, requested)?;
 				let total_gas = overflowing!(gas.overflow_add(provided));
 
 				InstructionRequirements {
@@ -271,7 +271,7 @@ impl<Gas: CostType> Gasometer<Gas> {
 				}
 			},
 			Request::GasMemCopy(gas, mem_size, copy) => {
-				let (mem_gas_cost, new_mem_gas, new_mem_size) = try!(self.mem_gas_cost(schedule, current_mem_size, &mem_size));
+				let (mem_gas_cost, new_mem_gas, new_mem_size) = self.mem_gas_cost(schedule, current_mem_size, &mem_size)?;
 				let copy = overflowing!(add_gas_usize(copy, 31)) >> 5;
 				let copy_gas = Gas::from(schedule.copy_gas) * copy;
 				let gas = overflowing!(gas.overflow_add(copy_gas));
@@ -303,7 +303,7 @@ impl<Gas: CostType> Gasometer<Gas> {
 		let req_mem_size_rounded = (overflowing!(mem_size.overflow_add(Gas::from(31 as usize))) >> 5) << 5;
 
 		let (mem_gas_cost, new_mem_gas) = if req_mem_size_rounded > current_mem_size {
-			let new_mem_gas = try!(gas_for_mem(req_mem_size_rounded));
+			let new_mem_gas = gas_for_mem(req_mem_size_rounded)?;
 			(new_mem_gas - self.current_mem_gas, new_mem_gas)
 		} else {
 			(Gas::from(0), self.current_mem_gas)

ethcore/src/evm/interpreter/mod.rs

@@ -107,7 +107,7 @@ impl<Cost: CostType> evm::Evm for Interpreter<Cost> {
 		let code = &params.code.as_ref().expect("exec always called with code; qed");
 		let valid_jump_destinations = self.cache.jump_destinations(&params.code_hash, code);
 
-		let mut gasometer = Gasometer::<Cost>::new(try!(Cost::from_u256(params.gas)));
+		let mut gasometer = Gasometer::<Cost>::new(Cost::from_u256(params.gas)?);
 		let mut stack = VecStack::with_capacity(ext.schedule().stack_limit, U256::zero());
 		let mut reader = CodeReader::new(code);
 		let infos = &*instructions::INSTRUCTIONS;
@@ -117,14 +117,14 @@ impl<Cost: CostType> evm::Evm for Interpreter<Cost> {
 			reader.position += 1;
 
 			let info = &infos[instruction as usize];
-			try!(self.verify_instruction(ext, instruction, info, &stack));
+			self.verify_instruction(ext, instruction, info, &stack)?;
 
 			// Calculate gas cost
-			let requirements = try!(gasometer.requirements(ext, instruction, info, &stack, self.mem.size()));
+			let requirements = gasometer.requirements(ext, instruction, info, &stack, self.mem.size())?;
 			// TODO: make compile-time removable if too much of a performance hit.
 			let trace_executed = ext.trace_prepare_execute(reader.position - 1, instruction, &requirements.gas_cost.as_u256());
 
-			try!(gasometer.verify_gas(&requirements.gas_cost));
+			gasometer.verify_gas(&requirements.gas_cost)?;
 			self.mem.expand(requirements.memory_required_size);
 			gasometer.current_mem_gas = requirements.memory_total_gas;
 			gasometer.current_gas = gasometer.current_gas - requirements.gas_cost;
@@ -137,9 +137,9 @@ impl<Cost: CostType> evm::Evm for Interpreter<Cost> {
 			};
 
 			// Execute instruction
-			let result = try!(self.exec_instruction(
+			let result = self.exec_instruction(
 				gasometer.current_gas, &params, ext, instruction, &mut reader, &mut stack, requirements.provide_gas
-			));
+			)?;
 
 			evm_debug!({ informant.after_instruction(instruction) });
 
@@ -154,7 +154,7 @@ impl<Cost: CostType> evm::Evm for Interpreter<Cost> {
 			// Advance
 			match result {
 				InstructionResult::JumpToPosition(position) => {
-					let pos = try!(self.verify_jump(position, &valid_jump_destinations));
+					let pos = self.verify_jump(position, &valid_jump_destinations)?;
 					reader.position = pos;
 				},
 				InstructionResult::StopExecutionNeedsReturn(gas, off, size) => {
@@ -513,7 +513,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 				stack.push(ext.env_info().gas_limit.clone());
 			},
 			_ => {
-				try!(self.exec_stack_instruction(instruction, stack));
+				self.exec_stack_instruction(instruction, stack)?;
 			}
 		};
 		Ok(InstructionResult::Ok)

ethcore/src/executive.rs

@@ -122,10 +122,10 @@ impl<'a> Executive<'a> {
 		mut tracer: T,
 		mut vm_tracer: V
 	) -> Result<Executed, ExecutionError> where T: Tracer, V: VMTracer {
-		let sender = try!(t.sender().map_err(|e| {
+		let sender = t.sender().map_err(|e| {
 			let message = format!("Transaction malformed: {:?}", e);
 			ExecutionError::TransactionMalformed(message)
-		}));
+		})?;
 		let nonce = self.state.nonce(&sender);
 
 		let schedule = self.engine.schedule(self.info);
@@ -206,7 +206,7 @@ impl<'a> Executive<'a> {
 		};
 
 		// finalize here!
-		Ok(try!(self.finalize(t, substate, gas_left, output, tracer.traces(), vm_tracer.drain())))
+		Ok(self.finalize(t, substate, gas_left, output, tracer.traces(), vm_tracer.drain())?)
 	}
 
 	fn exec_vm<T, V>(

ethcore/src/header.rs

@@ -265,26 +265,26 @@ impl Decodable for Header {
 		let r = decoder.as_rlp();
 
 		let mut blockheader = Header {
-			parent_hash: try!(r.val_at(0)),
+			parent_hash: r.val_at(0)?,
-			uncles_hash: try!(r.val_at(1)),
+			uncles_hash: r.val_at(1)?,
-			author: try!(r.val_at(2)),
+			author: r.val_at(2)?,
-			state_root: try!(r.val_at(3)),
+			state_root: r.val_at(3)?,
-			transactions_root: try!(r.val_at(4)),
+			transactions_root: r.val_at(4)?,
-			receipts_root: try!(r.val_at(5)),
+			receipts_root: r.val_at(5)?,
-			log_bloom: try!(r.val_at(6)),
+			log_bloom: r.val_at(6)?,
-			difficulty: try!(r.val_at(7)),
+			difficulty: r.val_at(7)?,
-			number: try!(r.val_at(8)),
+			number: r.val_at(8)?,
-			gas_limit: try!(r.val_at(9)),
+			gas_limit: r.val_at(9)?,
-			gas_used: try!(r.val_at(10)),
+			gas_used: r.val_at(10)?,
-			timestamp: try!(r.val_at(11)),
+			timestamp: r.val_at(11)?,
-			extra_data: try!(r.val_at(12)),
+			extra_data: r.val_at(12)?,
 			seal: vec![],
 			hash: RefCell::new(Some(r.as_raw().sha3())),
 			bare_hash: RefCell::new(None),
 		};
 
 		for i in 13..r.item_count() {
-			blockheader.seal.push(try!(r.at(i)).as_raw().to_vec())
+			blockheader.seal.push(r.at(i)?.as_raw().to_vec())
 		}
 
 		Ok(blockheader)

ethcore/src/migrations/state/v7.rs

@@ -109,7 +109,7 @@ impl OverlayRecentV7 {
 	// walk all journal entries in the database backwards.
 	// find migrations for any possible inserted keys.
 	fn walk_journal(&mut self, source: Arc<Database>) -> Result<(), Error> {
-		if let Some(val) = try!(source.get(None, V7_LATEST_ERA_KEY).map_err(Error::Custom)) {
+		if let Some(val) = source.get(None, V7_LATEST_ERA_KEY).map_err(Error::Custom)? {
 			let mut era = decode::<u64>(&val);
 			loop {
 				let mut index: usize = 0;
@@ -120,7 +120,7 @@ impl OverlayRecentV7 {
 						r.out()
 					};
 
-					if let Some(journal_raw) = try!(source.get(None, &entry_key).map_err(Error::Custom)) {
+					if let Some(journal_raw) = source.get(None, &entry_key).map_err(Error::Custom)? {
 						let rlp = Rlp::new(&journal_raw);
 
 						// migrate all inserted keys.
@@ -153,8 +153,8 @@ impl OverlayRecentV7 {
 	// replace all possible inserted/deleted keys with their migrated counterparts
 	// and commit the altered entries.
 	fn migrate_journal(&self, source: Arc<Database>, mut batch: Batch, dest: &mut Database) -> Result<(), Error> {
-		if let Some(val) = try!(source.get(None, V7_LATEST_ERA_KEY).map_err(Error::Custom)) {
+		if let Some(val) = source.get(None, V7_LATEST_ERA_KEY).map_err(Error::Custom)? {
-			try!(batch.insert(V7_LATEST_ERA_KEY.into(), val.clone().to_vec(), dest));
+			batch.insert(V7_LATEST_ERA_KEY.into(), val.clone().to_vec(), dest)?;
 
 			let mut era = decode::<u64>(&val);
 			loop {
@@ -166,7 +166,7 @@ impl OverlayRecentV7 {
 						r.out()
 					};
 
-					if let Some(journal_raw) = try!(source.get(None, &entry_key).map_err(Error::Custom)) {
+					if let Some(journal_raw) = source.get(None, &entry_key).map_err(Error::Custom)? {
 						let rlp = Rlp::new(&journal_raw);
 						let id: H256 = rlp.val_at(0);
 						let mut inserted_keys: Vec<(H256, Bytes)> = Vec::new();
@@ -202,7 +202,7 @@ impl OverlayRecentV7 {
 						stream.append(&deleted_keys);
 
 						// and insert it into the new database.
-						try!(batch.insert(entry_key, stream.out(), dest));
+						batch.insert(entry_key, stream.out(), dest)?;
 
 						index += 1;
 					} else {
@@ -233,7 +233,7 @@ impl Migration for OverlayRecentV7 {
 		let mut batch = Batch::new(config, col);
 
 		// check version metadata.
-		match try!(source.get(None, V7_VERSION_KEY).map_err(Error::Custom)) {
+		match source.get(None, V7_VERSION_KEY).map_err(Error::Custom)? {
 			Some(ref version) if decode::<u32>(&*version) == DB_VERSION => {}
 			_ => return Err(Error::MigrationImpossible), // missing or wrong version
 		}
@@ -255,10 +255,10 @@ impl Migration for OverlayRecentV7 {
 				}
 			}
 
-			try!(batch.insert(key, value.into_vec(), dest));
+			batch.insert(key, value.into_vec(), dest)?;
 		}
 
-		try!(self.walk_journal(source.clone()));
+		self.walk_journal(source.clone())?;
 		self.migrate_journal(source, batch, dest)
 	}
 }

ethcore/src/migrations/v10.rs

@@ -32,7 +32,7 @@ use util::{Database, DBTransaction};
 /// Can be called on upgraded database with no issues (will do nothing).
 pub fn generate_bloom(source: Arc<Database>, dest: &mut Database) -> Result<(), Error> {
 	trace!(target: "migration", "Account bloom upgrade started");
-	let best_block_hash = match try!(source.get(COL_EXTRA, b"best")) {
+	let best_block_hash = match source.get(COL_EXTRA, b"best")? {
 		// no migration needed
 		None => {
 			trace!(target: "migration", "No best block hash, skipping");
@@ -40,7 +40,7 @@ pub fn generate_bloom(source: Arc<Database>, dest: &mut Database) -> Result<(),
 		},
 		Some(hash) => hash,
 	};
-	let best_block_header = match try!(source.get(COL_HEADERS, &best_block_hash)) {
+	let best_block_header = match source.get(COL_HEADERS, &best_block_hash)? {
 		// no best block, nothing to do
 		None => {
 			trace!(target: "migration", "No best block header, skipping");
@@ -58,9 +58,9 @@ pub fn generate_bloom(source: Arc<Database>, dest: &mut Database) -> Result<(),
 			source.clone(),
 			journaldb::Algorithm::OverlayRecent,
 			COL_STATE);
-		let account_trie = try!(TrieDB::new(state_db.as_hashdb(), &state_root).map_err(|e| Error::Custom(format!("Cannot open trie: {:?}", e))));
+		let account_trie = TrieDB::new(state_db.as_hashdb(), &state_root).map_err(|e| Error::Custom(format!("Cannot open trie: {:?}", e)))?;
-		for item in try!(account_trie.iter().map_err(|_| Error::MigrationImpossible)) {
+		for item in account_trie.iter().map_err(|_| Error::MigrationImpossible)? {
-			let (ref account_key, _) = try!(item.map_err(|_| Error::MigrationImpossible));
+			let (ref account_key, _) = item.map_err(|_| Error::MigrationImpossible)?;
 			let account_key_hash = H256::from_slice(account_key);
 			bloom.set(&*account_key_hash);
 		}
@@ -71,8 +71,8 @@ pub fn generate_bloom(source: Arc<Database>, dest: &mut Database) -> Result<(),
 	trace!(target: "migration", "Generated {} bloom updates", bloom_journal.entries.len());
 
 	let mut batch = DBTransaction::new(dest);
-	try!(StateDB::commit_bloom(&mut batch, bloom_journal).map_err(|_| Error::Custom("Failed to commit bloom".to_owned())));
+	StateDB::commit_bloom(&mut batch, bloom_journal).map_err(|_| Error::Custom("Failed to commit bloom".to_owned()))?;
-	try!(dest.write(batch));
+	dest.write(batch)?;
 
 	trace!(target: "migration", "Finished bloom update");
 
@@ -104,12 +104,12 @@ impl Migration for ToV10 {
 		let mut batch = Batch::new(config, col);
 		for (key, value) in source.iter(col) {
 			self.progress.tick();
-			try!(batch.insert(key.to_vec(), value.to_vec(), dest));
+			batch.insert(key.to_vec(), value.to_vec(), dest)?;
 		}
-		try!(batch.commit(dest));
+		batch.commit(dest)?;
 
 		if col == COL_STATE {
-			try!(generate_bloom(source, dest));
+			generate_bloom(source, dest)?;
 		}
 
 		Ok(())

ethcore/src/migrations/v9.rs

@@ -63,17 +63,17 @@ impl Migration for ToV9 {
 			self.progress.tick();
 			match self.extract {
 				Extract::Header => {
-					try!(batch.insert(key.to_vec(), Rlp::new(&value).at(0).as_raw().to_vec(), dest))
+					batch.insert(key.to_vec(), Rlp::new(&value).at(0).as_raw().to_vec(), dest)?
 				},
 				Extract::Body => {
 					let mut body = RlpStream::new_list(2);
 					let block_rlp = Rlp::new(&value);
 					body.append_raw(block_rlp.at(1).as_raw(), 1);
 					body.append_raw(block_rlp.at(2).as_raw(), 1);
-					try!(batch.insert(key.to_vec(), body.out(), dest))
+					batch.insert(key.to_vec(), body.out(), dest)?
 				},
 				Extract::All => {
-					try!(batch.insert(key.to_vec(), value.to_vec(), dest))
+					batch.insert(key.to_vec(), value.to_vec(), dest)?
 				}
 			}
 		}

ethcore/src/miner/miner.rs

@@ -20,8 +20,6 @@ use std::time::{Instant, Duration};
 use util::*;
 use util::using_queue::{UsingQueue, GetAction};
 use account_provider::{AccountProvider, Error as AccountError};
-use views::{BlockView, HeaderView};
-use header::Header;
 use state::{State, CleanupMode};
 use client::{MiningBlockChainClient, Executive, Executed, EnvInfo, TransactOptions, BlockId, CallAnalytics, TransactionId};
 use client::TransactionImportResult;
@@ -536,7 +534,7 @@ impl Miner {
 	}
 
 	fn update_gas_limit(&self, chain: &MiningBlockChainClient) {
-		let gas_limit = HeaderView::new(&chain.best_block_header()).gas_limit();
+		let gas_limit = chain.best_block_header().gas_limit();
 		let mut queue = self.transaction_queue.lock();
 		queue.set_gas_limit(gas_limit);
 		if let GasLimit::Auto = self.options.tx_queue_gas_limit {
@@ -598,7 +596,7 @@ impl Miner {
 
 		let schedule = chain.latest_schedule();
 		let gas_required = |tx: &SignedTransaction| tx.gas_required(&schedule).into();
-		let best_block_header: Header = ::rlp::decode(&chain.best_block_header());
+		let best_block_header = chain.best_block_header().decode();
 		transactions.into_iter()
 			.map(|tx| {
 				if chain.transaction_block(TransactionId::Hash(tx.hash())).is_some() {
@@ -698,10 +696,10 @@ impl MinerService for Miner {
 				let mut state = block.state().clone();
 				let original_state = if analytics.state_diffing { Some(state.clone()) } else { None };
 
-				let sender = try!(t.sender().map_err(|e| {
+				let sender = t.sender().map_err(|e| {
 					let message = format!("Transaction malformed: {:?}", e);
 					ExecutionError::TransactionMalformed(message)
-				}));
+				})?;
 				let balance = state.balance(&sender);
 				let needed_balance = t.value + t.gas * t.gas_price;
 				if balance < needed_balance {
@@ -709,7 +707,7 @@ impl MinerService for Miner {
 					state.add_balance(&sender, &(needed_balance - balance), CleanupMode::NoEmpty);
 				}
 				let options = TransactOptions { tracing: analytics.transaction_tracing, vm_tracing: analytics.vm_tracing, check_nonce: false };
-				let mut ret = try!(Executive::new(&mut state, &env_info, &*self.engine, chain.vm_factory()).transact(t, options));
+				let mut ret = Executive::new(&mut state, &env_info, &*self.engine, chain.vm_factory()).transact(t, options)?;
 
 				// TODO gav move this into Executive.
 				ret.state_diff = original_state.map(|original| state.diff_from(original));
@@ -765,7 +763,7 @@ impl MinerService for Miner {
 	fn set_engine_signer(&self, address: Address, password: String) -> Result<(), AccountError> {
 		if self.seals_internally {
 			if let Some(ref ap) = self.accounts {
-				try!(ap.sign(address.clone(), Some(password.clone()), Default::default()));
+				ap.sign(address.clone(), Some(password.clone()), Default::default())?;
 			}
 			let mut sealing_work = self.sealing_work.lock();
 			sealing_work.enabled = self.engine.is_sealer(&address).unwrap_or(false);
@@ -1104,7 +1102,7 @@ impl MinerService for Miner {
 		result.and_then(|sealed| {
 			let n = sealed.header().number();
 			let h = sealed.header().hash();
-			try!(chain.import_sealed_block(sealed));
+			chain.import_sealed_block(sealed)?;
 			info!(target: "miner", "Submitted block imported OK. #{}: {}", Colour::White.bold().paint(format!("{}", n)), Colour::White.bold().paint(h.hex()));
 			Ok(())
 		})
@@ -1127,7 +1125,6 @@ impl MinerService for Miner {
 				.map(|hash| {
 					let block = chain.block(BlockId::Hash(*hash))
 						.expect("Client is sending message after commit to db and inserting to chain; the block is available; qed");
-					let block = BlockView::new(&block);
 					let txs = block.transactions();
 					// populate sender
 					for tx in &txs {

ethcore/src/miner/price_info.rs

@@ -65,7 +65,7 @@ impl<F: Fn(PriceInfo) + Sync + Send + 'static> Handler<HttpStream> for SetPriceH
 impl PriceInfo {
 	pub fn get<F: Fn(PriceInfo) + Sync + Send + 'static>(set_price: F) -> Result<(), ()> {
 		// TODO: Handle each error type properly
-		let client = try!(Client::new().map_err(|_| ()));
+		let client = Client::new().map_err(|_| ())?;
 		thread::spawn(move || {
 			let (tx, rx) = mpsc::channel();
 			let url = FromStr::from_str("http://api.etherscan.io/api?module=stats&action=ethprice")

ethcore/src/miner/transaction_queue.rs

@@ -264,7 +264,7 @@ struct VerifiedTransaction {
 
 impl VerifiedTransaction {
 	fn new(transaction: SignedTransaction, origin: TransactionOrigin, min_block: Option<BlockNumber>) -> Result<Self, Error> {
-		try!(transaction.sender());
+		transaction.sender()?;
 		Ok(VerifiedTransaction {
 			transaction: transaction,
 			origin: origin,
@@ -732,9 +732,9 @@ impl TransactionQueue {
 		}
 
 		// Verify signature
-		try!(tx.check_low_s());
+		tx.check_low_s()?;
 
-		let vtx = try!(VerifiedTransaction::new(tx, origin, min_block));
+		let vtx = VerifiedTransaction::new(tx, origin, min_block)?;
 		let client_account = fetch_account(&vtx.sender());
 
 		let cost = vtx.transaction.value + vtx.transaction.gas_price * vtx.transaction.gas;
@@ -1138,13 +1138,13 @@ impl TransactionQueue {
 		if nonce > next_nonce {
 			// We have a gap - put to future.
 			// Insert transaction (or replace old one with lower gas price)
-			try!(check_too_cheap(
+			check_too_cheap(
 				Self::replace_transaction(tx, state_nonce, min_gas_price, &mut self.future, &mut self.by_hash, &mut self.local_transactions)
-			));
+			)?;
 			// Enforce limit in Future
 			let removed = self.future.enforce_limit(&mut self.by_hash, &mut self.local_transactions);
 			// Return an error if this transaction was not imported because of limit.
-			try!(check_if_removed(&address, &nonce, removed));
+			check_if_removed(&address, &nonce, removed)?;
 
 			debug!(target: "txqueue", "Importing transaction to future: {:?}", hash);
 			debug!(target: "txqueue", "status: {:?}", self.status());
@@ -1156,9 +1156,9 @@ impl TransactionQueue {
 		self.move_matching_future_to_current(address, nonce + U256::one(), state_nonce);
 
 		// Replace transaction if any
-		try!(check_too_cheap(
+		check_too_cheap(
 			Self::replace_transaction(tx, state_nonce, min_gas_price, &mut self.current, &mut self.by_hash, &mut self.local_transactions)
-		));
+		)?;
 		// Keep track of highest nonce stored in current
 		let new_max = self.last_nonces.get(&address).map_or(nonce, |n| cmp::max(nonce, *n));
 		self.last_nonces.insert(address, new_max);
@@ -1168,7 +1168,7 @@ impl TransactionQueue {
 		// If some transaction were removed because of limit we need to update last_nonces also.
 		self.update_last_nonces(&removed);
 		// Trigger error if the transaction we are importing was removed.
-		try!(check_if_removed(&address, &nonce, removed));
+		check_if_removed(&address, &nonce, removed)?;
 
 		debug!(target: "txqueue", "Imported transaction to current: {:?}", hash);
 		debug!(target: "txqueue", "status: {:?}", self.status());

ethcore/src/pod_state.rs

@@ -64,7 +64,7 @@ impl From<ethjson::spec::State> for PodState {
 impl fmt::Display for PodState {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		for (add, acc) in &self.0 {
-			try!(writeln!(f, "{} => {}", add, acc));
+			writeln!(f, "{} => {}", add, acc)?;
 		}
 		Ok(())
 	}

ethcore/src/service.rs

@@ -77,7 +77,7 @@ impl ClientService {
 		) -> Result<ClientService, Error>
 	{
 		let panic_handler = PanicHandler::new_in_arc();
-		let io_service = try!(IoService::<ClientIoMessage>::start());
+		let io_service = IoService::<ClientIoMessage>::start()?;
 		panic_handler.forward_from(&io_service);
 
 		info!("Configured for {} using {} engine", Colour::White.bold().paint(spec.name.clone()), Colour::Yellow.bold().paint(spec.engine.name()));
@@ -94,7 +94,7 @@ impl ClientService {
 		db_config.wal = config.db_wal;
 
 		let pruning = config.pruning;
-		let client = try!(Client::new(config, &spec, client_path, miner, io_service.channel(), &db_config));
+		let client = Client::new(config, &spec, client_path, miner, io_service.channel(), &db_config)?;
 
 		let snapshot_params = SnapServiceParams {
 			engine: spec.engine.clone(),
@@ -105,14 +105,14 @@ impl ClientService {
 			snapshot_root: snapshot_path.into(),
 			db_restore: client.clone(),
 		};
-		let snapshot = Arc::new(try!(SnapshotService::new(snapshot_params)));
+		let snapshot = Arc::new(SnapshotService::new(snapshot_params)?);
 
 		panic_handler.forward_from(&*client);
 		let client_io = Arc::new(ClientIoHandler {
 			client: client.clone(),
 			snapshot: snapshot.clone(),
 		});
-		try!(io_service.register_handler(client_io));
+		io_service.register_handler(client_io)?;
 
 		spec.engine.register_message_channel(io_service.channel());
 

ethcore/src/snapshot/account.rs

@@ -100,12 +100,12 @@ impl Account {
 			return Ok(::rlp::NULL_RLP.to_vec());
 		}
 
-		let db = try!(TrieDB::new(acct_db, &self.storage_root));
+		let db = TrieDB::new(acct_db, &self.storage_root)?;
 
 		let mut pairs = Vec::new();
 
-		for item in try!(db.iter()) {
+		for item in db.iter()? {
-			let (k, v) = try!(item);
+			let (k, v) = item?;
 			pairs.push((k, v));
 		}
 
@@ -158,24 +158,24 @@ impl Account {
 			return Ok((ACC_EMPTY, None));
 		}
 
-		let nonce = try!(rlp.val_at(0));
+		let nonce = rlp.val_at(0)?;
-		let balance = try!(rlp.val_at(1));
+		let balance = rlp.val_at(1)?;
 		let code_state: CodeState = {
-			let raw: u8 = try!(rlp.val_at(2));
+			let raw: u8 = rlp.val_at(2)?;
-			try!(CodeState::from(raw))
+			CodeState::from(raw)?
 		};
 
 		// load the code if it exists.
 		let (code_hash, new_code) = match code_state {
 			CodeState::Empty => (SHA3_EMPTY, None),
 			CodeState::Inline => {
-				let code: Bytes = try!(rlp.val_at(3));
+				let code: Bytes = rlp.val_at(3)?;
 				let code_hash = acct_db.insert(&code);
 
 				(code_hash, Some(code))
 			}
 			CodeState::Hash => {
-				let code_hash = try!(rlp.val_at(3));
+				let code_hash = rlp.val_at(3)?;
 
 				(code_hash, None)
 			}
@@ -185,12 +185,12 @@ impl Account {
 
 		{
 			let mut storage_trie = TrieDBMut::new(acct_db, &mut storage_root);
-			let pairs = try!(rlp.at(4));
+			let pairs = rlp.at(4)?;
 			for pair_rlp in pairs.iter() {
-				let k: Bytes  = try!(pair_rlp.val_at(0));
+				let k: Bytes  = pair_rlp.val_at(0)?;
-				let v: Bytes = try!(pair_rlp.val_at(1));
+				let v: Bytes = pair_rlp.val_at(1)?;
 
-				try!(storage_trie.insert(&k, &v));
+				storage_trie.insert(&k, &v)?;
 			}
 		}
 

ethcore/src/snapshot/block.rs

@@ -89,21 +89,21 @@ impl AbridgedBlock {
 
 		let mut header: Header = Default::default();
 		header.set_parent_hash(parent_hash);
-		header.set_author(try!(rlp.val_at(0)));
+		header.set_author(rlp.val_at(0)?);
-		header.set_state_root(try!(rlp.val_at(1)));
+		header.set_state_root(rlp.val_at(1)?);
-		header.set_log_bloom(try!(rlp.val_at(2)));
+		header.set_log_bloom(rlp.val_at(2)?);
-		header.set_difficulty(try!(rlp.val_at(3)));
+		header.set_difficulty(rlp.val_at(3)?);
 		header.set_number(number);
-		header.set_gas_limit(try!(rlp.val_at(4)));
+		header.set_gas_limit(rlp.val_at(4)?);
-		header.set_gas_used(try!(rlp.val_at(5)));
+		header.set_gas_used(rlp.val_at(5)?);
-		header.set_timestamp(try!(rlp.val_at(6)));
+		header.set_timestamp(rlp.val_at(6)?);
-		header.set_extra_data(try!(rlp.val_at(7)));
+		header.set_extra_data(rlp.val_at(7)?);
 
-		let transactions = try!(rlp.val_at(8));
+		let transactions = rlp.val_at(8)?;
-		let uncles: Vec<Header> = try!(rlp.val_at(9));
+		let uncles: Vec<Header> = rlp.val_at(9)?;
 
 		header.set_transactions_root(ordered_trie_root(
-			try!(rlp.at(8)).iter().map(|r| r.as_raw().to_owned())
+			rlp.at(8)?.iter().map(|r| r.as_raw().to_owned())
 		));
 		header.set_receipts_root(receipts_root);
 
@@ -113,7 +113,7 @@ impl AbridgedBlock {
 
 		let mut seal_fields = Vec::new();
 		for i in (HEADER_FIELDS + BLOCK_FIELDS)..rlp.item_count() {
-			let seal_rlp = try!(rlp.at(i));
+			let seal_rlp = rlp.at(i)?;
 			seal_fields.push(seal_rlp.as_raw().to_owned());
 		}
 

ethcore/src/snapshot/io.rs

@@ -60,9 +60,9 @@ impl rlp::Decodable for ChunkInfo {
 	fn decode<D: rlp::Decoder>(decoder: &D) -> Result<Self, rlp::DecoderError> {
 		let d = decoder.as_rlp();
 
-		let hash = try!(d.val_at(0));
+		let hash = d.val_at(0)?;
-		let len = try!(d.val_at(1));
+		let len = d.val_at(1)?;
-		let off = try!(d.val_at(2));
+		let off = d.val_at(2)?;
 		Ok(ChunkInfo(hash, len, off))
 	}
 }
@@ -88,7 +88,7 @@ impl PackedWriter {
 	/// Create a new "PackedWriter", to write into the file at the given path.
 	pub fn new(path: &Path) -> io::Result<Self> {
 		Ok(PackedWriter {
-			file: try!(File::create(path)),
+			file: File::create(path)?,
 			state_hashes: Vec::new(),
 			block_hashes: Vec::new(),
 			cur_len: 0,
@@ -98,7 +98,7 @@ impl PackedWriter {
 
 impl SnapshotWriter for PackedWriter {
 	fn write_state_chunk(&mut self, hash: H256, chunk: &[u8]) -> io::Result<()> {
-		try!(self.file.write_all(chunk));
+		self.file.write_all(chunk)?;
 
 		let len = chunk.len() as u64;
 		self.state_hashes.push(ChunkInfo(hash, len, self.cur_len));
@@ -108,7 +108,7 @@ impl SnapshotWriter for PackedWriter {
 	}
 
 	fn write_block_chunk(&mut self, hash: H256, chunk: &[u8]) -> io::Result<()> {
-		try!(self.file.write_all(chunk));
+		self.file.write_all(chunk)?;
 
 		let len = chunk.len() as u64;
 		self.block_hashes.push(ChunkInfo(hash, len, self.cur_len));
@@ -130,7 +130,7 @@ impl SnapshotWriter for PackedWriter {
 
 		let manifest_rlp = stream.out();
 
-		try!(self.file.write_all(&manifest_rlp));
+		self.file.write_all(&manifest_rlp)?;
 		let off = self.cur_len;
 		trace!(target: "snapshot_io", "writing manifest of len {} to offset {}", manifest_rlp.len(), off);
 
@@ -146,7 +146,7 @@ impl SnapshotWriter for PackedWriter {
 				(off >> 56) as u8,
 			];
 
-		try!(self.file.write_all(&off_bytes[..]));
+		self.file.write_all(&off_bytes[..])?;
 
 		Ok(())
 	}
@@ -161,7 +161,7 @@ impl LooseWriter {
 	/// Create a new LooseWriter which will write into the given directory,
 	/// creating it if it doesn't exist.
 	pub fn new(path: PathBuf) -> io::Result<Self> {
-		try!(fs::create_dir_all(&path));
+		fs::create_dir_all(&path)?;
 
 		Ok(LooseWriter {
 			dir: path,
@@ -173,8 +173,8 @@ impl LooseWriter {
 		let mut file_path = self.dir.clone();
 		file_path.push(hash.hex());
 
-		let mut file = try!(File::create(file_path));
+		let mut file = File::create(file_path)?;
-		try!(file.write_all(chunk));
+		file.write_all(chunk)?;
 
 		Ok(())
 	}
@@ -194,8 +194,8 @@ impl SnapshotWriter for LooseWriter {
 		let mut path = self.dir.clone();
 		path.push("MANIFEST");
 
-		let mut file = try!(File::create(path));
+		let mut file = File::create(path)?;
-		try!(file.write_all(&rlp[..]));
+		file.write_all(&rlp[..])?;
 
 		Ok(())
 	}
@@ -224,18 +224,18 @@ impl PackedReader {
 	/// This will fail if any io errors are encountered or the file
 	/// is not a valid packed snapshot.
 	pub fn new(path: &Path) -> Result<Option<Self>, ::error::Error> {
-		let mut file = try!(File::open(path));
+		let mut file = File::open(path)?;
-		let file_len = try!(file.metadata()).len();
+		let file_len = file.metadata()?.len();
 		if file_len < 8 {
 			// ensure we don't seek before beginning.
 			return Ok(None);
 		}
 
 
-		try!(file.seek(SeekFrom::End(-8)));
+		file.seek(SeekFrom::End(-8))?;
 		let mut off_bytes = [0u8; 8];
 
-		try!(file.read_exact(&mut off_bytes[..]));
+		file.read_exact(&mut off_bytes[..])?;
 
 		let manifest_off: u64 =
 			((off_bytes[7] as u64) << 56) +
@@ -252,20 +252,20 @@ impl PackedReader {
 
 		let	mut manifest_buf = vec![0; manifest_len as usize];
 
-		try!(file.seek(SeekFrom::Start(manifest_off)));
+		file.seek(SeekFrom::Start(manifest_off))?;
-		try!(file.read_exact(&mut manifest_buf));
+		file.read_exact(&mut manifest_buf)?;
 
 		let rlp = UntrustedRlp::new(&manifest_buf);
 
-		let state: Vec<ChunkInfo> = try!(rlp.val_at(0));
+		let state: Vec<ChunkInfo> = rlp.val_at(0)?;
-		let blocks: Vec<ChunkInfo> = try!(rlp.val_at(1));
+		let blocks: Vec<ChunkInfo> = rlp.val_at(1)?;
 
 		let manifest = ManifestData {
 			state_hashes: state.iter().map(|c| c.0).collect(),
 			block_hashes: blocks.iter().map(|c| c.0).collect(),
-			state_root: try!(rlp.val_at(2)),
+			state_root: rlp.val_at(2)?,
-			block_number: try!(rlp.val_at(3)),
+			block_number: rlp.val_at(3)?,
-			block_hash: try!(rlp.val_at(4)),
+			block_hash: rlp.val_at(4)?,
 		};
 
 		Ok(Some(PackedReader {
@@ -288,10 +288,10 @@ impl SnapshotReader for PackedReader {
 
 		let mut file = &self.file;
 
-		try!(file.seek(SeekFrom::Start(off)));
+		file.seek(SeekFrom::Start(off))?;
 		let mut buf = vec![0; len as usize];
 
-		try!(file.read_exact(&mut buf[..]));
+		file.read_exact(&mut buf[..])?;
 
 		Ok(buf)
 	}
@@ -310,10 +310,10 @@ impl LooseReader {
 		let mut manifest_buf = Vec::new();
 
 		dir.push("MANIFEST");
-		let mut manifest_file = try!(File::open(&dir));
+		let mut manifest_file = File::open(&dir)?;
-		try!(manifest_file.read_to_end(&mut manifest_buf));
+		manifest_file.read_to_end(&mut manifest_buf)?;
 
-		let manifest = try!(ManifestData::from_rlp(&manifest_buf[..]));
+		let manifest = ManifestData::from_rlp(&manifest_buf[..])?;
 
 		dir.pop();
 
@@ -334,9 +334,9 @@ impl SnapshotReader for LooseReader {
 		path.push(hash.hex());
 
 		let mut buf = Vec::new();
-		let mut file = try!(File::open(&path));
+		let mut file = File::open(&path)?;
 
-		try!(file.read_to_end(&mut buf));
+		file.read_to_end(&mut buf)?;
 
 		Ok(buf)
 	}

ethcore/src/snapshot/mod.rs

@@ -128,22 +128,22 @@ pub fn take_snapshot<W: SnapshotWriter + Send>(
 	writer: W,
 	p: &Progress
 ) -> Result<(), Error> {
-	let start_header = try!(chain.block_header(&block_at)
+	let start_header = chain.block_header(&block_at)
-		.ok_or(Error::InvalidStartingBlock(BlockId::Hash(block_at))));
+		.ok_or(Error::InvalidStartingBlock(BlockId::Hash(block_at)))?;
 	let state_root = start_header.state_root();
 	let number = start_header.number();
 
 	info!("Taking snapshot starting at block {}", number);
 
 	let writer = Mutex::new(writer);
-	let (state_hashes, block_hashes) = try!(scope(|scope| {
+	let (state_hashes, block_hashes) = scope(|scope| {
 		let block_guard = scope.spawn(|| chunk_blocks(chain, block_at, &writer, p));
 		let state_res = chunk_state(state_db, state_root, &writer, p);
 
 		state_res.and_then(|state_hashes| {
 			block_guard.join().map(|block_hashes| (state_hashes, block_hashes))
 		})
-	}));
+	})?;
 
 	info!("produced {} state chunks and {} block chunks.", state_hashes.len(), block_hashes.len());
 
@@ -155,7 +155,7 @@ pub fn take_snapshot<W: SnapshotWriter + Send>(
 		block_hash: block_at,
 	};
 
-	try!(writer.into_inner().finish(manifest_data));
+	writer.into_inner().finish(manifest_data)?;
 
 	p.done.store(true, Ordering::SeqCst);
 
@@ -186,12 +186,11 @@ impl<'a> BlockChunker<'a> {
 		for _ in 0..SNAPSHOT_BLOCKS {
 			if self.current_hash == genesis_hash { break }
 
-			let (block, receipts) = try!(self.chain.block(&self.current_hash)
+			let (block, receipts) = self.chain.block(&self.current_hash)
 				.and_then(|b| self.chain.block_receipts(&self.current_hash).map(|r| (b, r)))
-				.ok_or(Error::BlockNotFound(self.current_hash)));
+				.ok_or(Error::BlockNotFound(self.current_hash))?;
 
-			let view = BlockView::new(&block);
+			let abridged_rlp = AbridgedBlock::from_block_view(&block.view()).into_inner();
-			let abridged_rlp = AbridgedBlock::from_block_view(&view).into_inner();
 
 			let pair = {
 				let mut pair_stream = RlpStream::new_list(2);
@@ -204,7 +203,7 @@ impl<'a> BlockChunker<'a> {
 			// cut off the chunk if too large.
 
 			if new_loaded_size > PREFERRED_CHUNK_SIZE && !self.rlps.is_empty() {
-				try!(self.write_chunk(last));
+				self.write_chunk(last)?;
 				loaded_size = pair.len();
 			} else {
 				loaded_size = new_loaded_size;
@@ -213,11 +212,11 @@ impl<'a> BlockChunker<'a> {
 			self.rlps.push_front(pair);
 
 			last = self.current_hash;
-			self.current_hash = view.header_view().parent_hash();
+			self.current_hash = block.header_view().parent_hash();
 		}
 
 		if loaded_size != 0 {
-			try!(self.write_chunk(last));
+			self.write_chunk(last)?;
 		}
 
 		Ok(())
@@ -230,9 +229,9 @@ impl<'a> BlockChunker<'a> {
 	fn write_chunk(&mut self, last: H256) -> Result<(), Error> {
 		trace!(target: "snapshot", "prepared block chunk with {} blocks", self.rlps.len());
 
-		let (last_header, last_details) = try!(self.chain.block_header(&last)
+		let (last_header, last_details) = self.chain.block_header(&last)
 			.and_then(|n| self.chain.block_details(&last).map(|d| (n, d)))
-			.ok_or(Error::BlockNotFound(last)));
+			.ok_or(Error::BlockNotFound(last))?;
 
 		let parent_number = last_header.number() - 1;
 		let parent_hash = last_header.parent_hash();
@@ -254,7 +253,7 @@ impl<'a> BlockChunker<'a> {
 		let compressed = &self.snappy_buffer[..size];
 		let hash = compressed.sha3();
 
-		try!(self.writer.lock().write_block_chunk(hash, compressed));
+		self.writer.lock().write_block_chunk(hash, compressed)?;
 		trace!(target: "snapshot", "wrote block chunk. hash: {}, size: {}, uncompressed size: {}", hash.hex(), size, raw_data.len());
 
 		self.progress.size.fetch_add(size, Ordering::SeqCst);
@@ -282,7 +281,7 @@ pub fn chunk_blocks<'a>(chain: &'a BlockChain, start_hash: H256, writer: &Mutex<
 		progress: progress,
 	};
 
-	try!(chunker.chunk_all());
+	chunker.chunk_all()?;
 
 	Ok(chunker.hashes)
 }
@@ -310,7 +309,7 @@ impl<'a> StateChunker<'a> {
 		};
 
 		if self.cur_size + pair.len() >= PREFERRED_CHUNK_SIZE {
-			try!(self.write_chunk());
+			self.write_chunk()?;
 		}
 
 		self.cur_size += pair.len();
@@ -334,7 +333,7 @@ impl<'a> StateChunker<'a> {
 		let compressed = &self.snappy_buffer[..compressed_size];
 		let hash = compressed.sha3();
 
-		try!(self.writer.lock().write_state_chunk(hash, compressed));
+		self.writer.lock().write_state_chunk(hash, compressed)?;
 		trace!(target: "snapshot", "wrote state chunk. size: {}, uncompressed size: {}", compressed_size, raw_data.len());
 
 		self.progress.accounts.fetch_add(num_entries, Ordering::SeqCst);
@@ -353,7 +352,7 @@ impl<'a> StateChunker<'a> {
 /// Returns a list of hashes of chunks created, or any error it may
 /// have encountered.
 pub fn chunk_state<'a>(db: &HashDB, root: &H256, writer: &Mutex<SnapshotWriter + 'a>, progress: &'a Progress) -> Result<Vec<H256>, Error> {
-	let account_trie = try!(TrieDB::new(db, &root));
+	let account_trie = TrieDB::new(db, &root)?;
 
 	let mut chunker = StateChunker {
 		hashes: Vec::new(),
@@ -367,19 +366,19 @@ pub fn chunk_state<'a>(db: &HashDB, root: &H256, writer: &Mutex<SnapshotWriter +
 	let mut used_code = HashSet::new();
 
 	// account_key here is the address' hash.
-	for item in try!(account_trie.iter()) {
+	for item in account_trie.iter()? {
-		let (account_key, account_data) = try!(item);
+		let (account_key, account_data) = item?;
 		let account = Account::from_thin_rlp(&*account_data);
 		let account_key_hash = H256::from_slice(&account_key);
 
 		let account_db = AccountDB::from_hash(db, account_key_hash);
 
-		let fat_rlp = try!(account.to_fat_rlp(&account_db, &mut used_code));
+		let fat_rlp = account.to_fat_rlp(&account_db, &mut used_code)?;
-		try!(chunker.push(account_key, fat_rlp));
+		chunker.push(account_key, fat_rlp)?;
 	}
 
 	if chunker.cur_size != 0 {
-		try!(chunker.write_chunk());
+		chunker.write_chunk()?;
 	}
 
 	Ok(chunker.hashes)
@@ -415,13 +414,13 @@ impl StateRebuilder {
 		// initialize the pairs vector with empty values so we have slots to write into.
 		pairs.resize(rlp.item_count(), (H256::new(), Vec::new()));
 
-		let status = try!(rebuild_accounts(
+		let status = rebuild_accounts(
 			self.db.as_hashdb_mut(),
 			rlp,
 			&mut pairs,
 			&self.known_code,
 			flag
-		));
+		)?;
 
 		for (addr_hash, code_hash) in status.missing_code {
 			self.missing_code.entry(code_hash).or_insert_with(Vec::new).push(addr_hash);
@@ -442,7 +441,7 @@ impl StateRebuilder {
 		// batch trie writes
 		{
 			let mut account_trie = if self.state_root != SHA3_NULL_RLP {
-				try!(TrieDBMut::from_existing(self.db.as_hashdb_mut(), &mut self.state_root))
+				TrieDBMut::from_existing(self.db.as_hashdb_mut(), &mut self.state_root)?
 			} else {
 				TrieDBMut::new(self.db.as_hashdb_mut(), &mut self.state_root)
 			};
@@ -453,14 +452,14 @@ impl StateRebuilder {
 				if &thin_rlp[..] != &empty_rlp[..] {
 					self.bloom.set(&*hash);
 				}
-				try!(account_trie.insert(&hash, &thin_rlp));
+				account_trie.insert(&hash, &thin_rlp)?;
 			}
 		}
 
 		let bloom_journal = self.bloom.drain_journal();
 		let mut batch = backing.transaction();
-		try!(StateDB::commit_bloom(&mut batch, bloom_journal));
+		StateDB::commit_bloom(&mut batch, bloom_journal)?;
-		try!(self.db.inject(&mut batch));
+		self.db.inject(&mut batch)?;
 		backing.write_buffered(batch);
 		trace!(target: "snapshot", "current state root: {:?}", self.state_root);
 		Ok(())
@@ -500,15 +499,15 @@ fn rebuild_accounts(
 	for (account_rlp, out) in account_fat_rlps.into_iter().zip(out_chunk) {
 		if !abort_flag.load(Ordering::SeqCst) { return Err(Error::RestorationAborted.into()) }
 
-		let hash: H256 = try!(account_rlp.val_at(0));
+		let hash: H256 = account_rlp.val_at(0)?;
-		let fat_rlp = try!(account_rlp.at(1));
+		let fat_rlp = account_rlp.at(1)?;
 
 		let thin_rlp = {
 
 			// fill out the storage trie and code while decoding.
 			let (acc, maybe_code) = {
 				let mut acct_db = AccountDBMut::from_hash(db, hash);
-				try!(Account::from_fat_rlp(&mut acct_db, fat_rlp))
+				Account::from_fat_rlp(&mut acct_db, fat_rlp)?
 			};
 
 			let code_hash = acc.code_hash().clone();
@@ -521,9 +520,9 @@ fn rebuild_accounts(
 						match known_code.get(&code_hash) {
 							Some(&first_with) => {
 								// if so, load it from the database.
-								let code = try!(AccountDB::from_hash(db, first_with)
+								let code = AccountDB::from_hash(db, first_with)
 									.get(&code_hash)
-									.ok_or_else(|| Error::MissingCode(vec![first_with])));
+									.ok_or_else(|| Error::MissingCode(vec![first_with]))?;
 
 								// and write it again under a different mangled key
 								AccountDBMut::from_hash(db, hash).emplace(code_hash, code);
@@ -586,7 +585,7 @@ impl BlockRebuilder {
 		Ok(BlockRebuilder {
 			chain: chain,
 			db: db,
-			rng: try!(OsRng::new()),
+			rng: OsRng::new()?,
 			disconnected: Vec::new(),
 			best_number: manifest.block_number,
 			best_hash: manifest.block_hash,
@@ -613,22 +612,22 @@ impl BlockRebuilder {
 		}
 
 		// todo: assert here that these values are consistent with chunks being in order.
-		let mut cur_number = try!(rlp.val_at::<u64>(0)) + 1;
+		let mut cur_number = rlp.val_at::<u64>(0)? + 1;
-		let mut parent_hash = try!(rlp.val_at::<H256>(1));
+		let mut parent_hash = rlp.val_at::<H256>(1)?;
-		let parent_total_difficulty = try!(rlp.val_at::<U256>(2));
+		let parent_total_difficulty = rlp.val_at::<U256>(2)?;
 
 		for idx in 3..item_count {
 			if !abort_flag.load(Ordering::SeqCst) { return Err(Error::RestorationAborted.into()) }
 
-			let pair = try!(rlp.at(idx));
+			let pair = rlp.at(idx)?;
-			let abridged_rlp = try!(pair.at(0)).as_raw().to_owned();
+			let abridged_rlp = pair.at(0)?.as_raw().to_owned();
 			let abridged_block = AbridgedBlock::from_raw(abridged_rlp);
-			let receipts: Vec<::receipt::Receipt> = try!(pair.val_at(1));
+			let receipts: Vec<::receipt::Receipt> = pair.val_at(1)?;
 			let receipts_root = ordered_trie_root(
-				try!(pair.at(1)).iter().map(|r| r.as_raw().to_owned())
+				pair.at(1)?.iter().map(|r| r.as_raw().to_owned())
 			);
 
-			let block = try!(abridged_block.to_block(parent_hash, cur_number, receipts_root));
+			let block = abridged_block.to_block(parent_hash, cur_number, receipts_root)?;
 			let block_bytes = block.rlp_bytes(With);
 			let is_best = cur_number == self.best_number;
 
@@ -642,14 +641,14 @@ impl BlockRebuilder {
 				}
 			}
 
-			try!(verify_old_block(
+			verify_old_block(
 				&mut self.rng,
 				&block.header,
 				engine,
 				&self.chain,
 				Some(&block_bytes),
 				is_best
-			));
+			)?;
 
 			let mut batch = self.db.transaction();
 
@@ -693,7 +692,7 @@ impl BlockRebuilder {
 		let best_number = self.best_number;
 		for num in (0..self.fed_blocks).map(|x| best_number - x) {
 
-			let hash = try!(self.chain.block_hash(num).ok_or(Error::IncompleteChain));
+			let hash = self.chain.block_hash(num).ok_or(Error::IncompleteChain)?;
 
 			if let Some(canon_hash) = canonical.get(&num).cloned() {
 				if canon_hash != hash {

ethcore/src/snapshot/service.rs

@@ -97,11 +97,11 @@ impl Restoration {
 		let state_chunks = manifest.state_hashes.iter().cloned().collect();
 		let block_chunks = manifest.block_hashes.iter().cloned().collect();
 
-		let raw_db = Arc::new(try!(Database::open(params.db_config, &*params.db_path.to_string_lossy())
+		let raw_db = Arc::new(Database::open(params.db_config, &*params.db_path.to_string_lossy())
-			.map_err(UtilError::SimpleString)));
+			.map_err(UtilError::SimpleString)?);
 
 		let chain = BlockChain::new(Default::default(), params.genesis, raw_db.clone(), params.engine);
-		let blocks = try!(BlockRebuilder::new(chain, raw_db.clone(), &manifest));
+		let blocks = BlockRebuilder::new(chain, raw_db.clone(), &manifest)?;
 
 		let root = manifest.state_root.clone();
 		Ok(Restoration {
@@ -122,12 +122,12 @@ impl Restoration {
 	// feeds a state chunk, aborts early if `flag` becomes false.
 	fn feed_state(&mut self, hash: H256, chunk: &[u8], flag: &AtomicBool) -> Result<(), Error> {
 		if self.state_chunks_left.remove(&hash) {
-			let len = try!(snappy::decompress_into(chunk, &mut self.snappy_buffer));
+			let len = snappy::decompress_into(chunk, &mut self.snappy_buffer)?;
 
-			try!(self.state.feed(&self.snappy_buffer[..len], flag));
+			self.state.feed(&self.snappy_buffer[..len], flag)?;
 
 			if let Some(ref mut writer) = self.writer.as_mut() {
-				try!(writer.write_state_chunk(hash, chunk));
+				writer.write_state_chunk(hash, chunk)?;
 			}
 		}
 
@@ -137,11 +137,11 @@ impl Restoration {
 	// feeds a block chunk
 	fn feed_blocks(&mut self, hash: H256, chunk: &[u8], engine: &Engine, flag: &AtomicBool) -> Result<(), Error> {
 		if self.block_chunks_left.remove(&hash) {
-			let len = try!(snappy::decompress_into(chunk, &mut self.snappy_buffer));
+			let len = snappy::decompress_into(chunk, &mut self.snappy_buffer)?;
 
-			try!(self.blocks.feed(&self.snappy_buffer[..len], engine, flag));
+			self.blocks.feed(&self.snappy_buffer[..len], engine, flag)?;
 			if let Some(ref mut writer) = self.writer.as_mut() {
-				 try!(writer.write_block_chunk(hash, chunk));
+				 writer.write_block_chunk(hash, chunk)?;
 			}
 		}
 
@@ -167,13 +167,13 @@ impl Restoration {
 		}
 
 		// check for missing code.
-		try!(self.state.check_missing());
+		self.state.check_missing()?;
 
 		// connect out-of-order chunks and verify chain integrity.
-		try!(self.blocks.finalize(self.canonical_hashes));
+		self.blocks.finalize(self.canonical_hashes)?;
 
 		if let Some(writer) = self.writer {
-			try!(writer.finish(self.manifest));
+			writer.finish(self.manifest)?;
 		}
 
 		self.guard.disarm();
@@ -315,7 +315,7 @@ impl Service {
 	fn replace_client_db(&self) -> Result<(), Error> {
 		let our_db = self.restoration_db();
 
-		try!(self.db_restore.restore_db(&*our_db.to_string_lossy()));
+		self.db_restore.restore_db(&*our_db.to_string_lossy())?;
 		Ok(())
 	}
 
@@ -351,7 +351,7 @@ impl Service {
 
 		let _ = fs::remove_dir_all(&temp_dir);
 
-		let writer = try!(LooseWriter::new(temp_dir.clone()));
+		let writer = LooseWriter::new(temp_dir.clone())?;
 
 		let guard = Guard::new(temp_dir.clone());
 		let res = client.take_snapshot(writer, BlockId::Number(num), &self.progress);
@@ -378,12 +378,12 @@ impl Service {
 		*reader = None;
 
 		if snapshot_dir.exists() {
-			try!(fs::remove_dir_all(&snapshot_dir));
+			fs::remove_dir_all(&snapshot_dir)?;
 		}
 
-		try!(fs::rename(temp_dir, &snapshot_dir));
+		fs::rename(temp_dir, &snapshot_dir)?;
 
-		*reader = Some(try!(LooseReader::new(snapshot_dir)));
+		*reader = Some(LooseReader::new(snapshot_dir)?);
 
 		guard.disarm();
 		Ok(())
@@ -410,11 +410,11 @@ impl Service {
 			}
 		}
 
-		try!(fs::create_dir_all(&rest_dir));
+		fs::create_dir_all(&rest_dir)?;
 
 		// make new restoration.
 		let writer = match recover {
-			true => Some(try!(LooseWriter::new(self.temp_recovery_dir()))),
+			true => Some(LooseWriter::new(self.temp_recovery_dir())?),
 			false => None
 		};
 
@@ -432,7 +432,7 @@ impl Service {
 		let state_chunks = params.manifest.state_hashes.len();
 		let block_chunks = params.manifest.block_hashes.len();
 
-		*res = Some(try!(Restoration::new(params)));
+		*res = Some(Restoration::new(params)?);
 
 		*self.status.lock() = RestorationStatus::Ongoing {
 			state_chunks: state_chunks as u32,
@@ -454,8 +454,8 @@ impl Service {
 		let recover = rest.as_ref().map_or(false, |rest| rest.writer.is_some());
 
 		// destroy the restoration before replacing databases and snapshot.
-		try!(rest.take().map(Restoration::finalize).unwrap_or(Ok(())));
+		rest.take().map(Restoration::finalize).unwrap_or(Ok(()))?;
-		try!(self.replace_client_db());
+		self.replace_client_db()?;
 
 		if recover {
 			let mut reader = self.reader.write();
@@ -465,13 +465,13 @@ impl Service {
 
 			if snapshot_dir.exists() {
 				trace!(target: "snapshot", "removing old snapshot dir at {}", snapshot_dir.to_string_lossy());
-				try!(fs::remove_dir_all(&snapshot_dir));
+				fs::remove_dir_all(&snapshot_dir)?;
 			}
 
 			trace!(target: "snapshot", "copying restored snapshot files over");
-			try!(fs::rename(self.temp_recovery_dir(), &snapshot_dir));
+			fs::rename(self.temp_recovery_dir(), &snapshot_dir)?;
 
-			*reader = Some(try!(LooseReader::new(snapshot_dir)));
+			*reader = Some(LooseReader::new(snapshot_dir)?);
 		}
 
 		let _ = fs::remove_dir_all(self.restoration_dir());
@@ -510,7 +510,7 @@ impl Service {
 
 							match is_done {
 								true => {
-									try!(db.flush().map_err(::util::UtilError::SimpleString));
+									db.flush().map_err(::util::UtilError::SimpleString)?;
 									drop(db);
 									return self.finalize_restoration(&mut *restoration);
 								},

ethcore/src/snapshot/watcher.rs

@@ -20,7 +20,6 @@ use util::Mutex;
 use client::{BlockChainClient, Client, ChainNotify};
 use ids::BlockId;
 use service::ClientIoMessage;
-use views::HeaderView;
 
 use io::IoChannel;
 use util::{H256, Bytes};
@@ -43,7 +42,7 @@ impl<F> Oracle for StandardOracle<F>
 	where F: Send + Sync + Fn() -> bool
 {
 	fn to_number(&self, hash: H256) -> Option<u64> {
-		self.client.block_header(BlockId::Hash(hash)).map(|h| HeaderView::new(&h).number())
+		self.client.block_header(BlockId::Hash(hash)).map(|h| h.number())
 	}
 
 	fn is_major_importing(&self) -> bool {

ethcore/src/spec/spec.rs

@@ -19,6 +19,13 @@
 use util::*;
 use builtin::Builtin;
 use engines::{Engine, NullEngine, InstantSeal, BasicAuthority, AuthorityRound, Tendermint};
+use factory::Factories;
+use executive::Executive;
+use trace::{NoopTracer, NoopVMTracer};
+use action_params::{ActionValue, ActionParams};
+use types::executed::CallType;
+use state::{State, Substate};
+use env_info::EnvInfo;
 use pod_state::*;
 use account_db::*;
 use header::{BlockNumber, Header};
@@ -99,10 +106,13 @@ pub struct Spec {
 	/// Each seal field, expressed as RLP, concatenated.
 	pub seal_rlp: Bytes,
 
-	// May be prepopulated if we know this in advance.
+	/// Contract constructors to be executed on genesis.
+	constructors: Vec<(Address, Bytes)>,
+
+	/// May be prepopulated if we know this in advance.
 	state_root_memo: RwLock<Option<H256>>,
 
-	// Genesis state as plain old data.
+	/// Genesis state as plain old data.
 	genesis_state: PodState,
 }
 
@@ -128,6 +138,7 @@ impl From<ethjson::spec::Spec> for Spec {
 			timestamp: g.timestamp,
 			extra_data: g.extra_data,
 			seal_rlp: seal_rlp,
+			constructors: s.accounts.constructors().into_iter().map(|(a, c)| (a.into(), c.into())).collect(),
 			state_root_memo: RwLock::new(g.state_root),
 			genesis_state: From::from(s.accounts),
 		}
@@ -238,25 +249,71 @@ impl Spec {
 	}
 
 	/// Ensure that the given state DB has the trie nodes in for the genesis state.
-	pub fn ensure_db_good(&self, db: &mut StateDB, factory: &TrieFactory) -> Result<bool, Box<TrieError>> {
+	pub fn ensure_db_good(&self, mut db: StateDB, factories: &Factories) -> Result<StateDB, Box<TrieError>> {
-		if !db.as_hashdb().contains(&self.state_root()) {
+		if db.as_hashdb().contains(&self.state_root()) {
-			trace!(target: "spec", "ensure_db_good: Fresh database? Cannot find state root {}", self.state_root());
+			return Ok(db)
-			let mut root = H256::new();
+		}
+		trace!(target: "spec", "ensure_db_good: Fresh database? Cannot find state root {}", self.state_root());
+		let mut root = H256::new();
 
+		{
+			let mut t = factories.trie.create(db.as_hashdb_mut(), &mut root);
+			for (address, account) in self.genesis_state.get().iter() {
+				t.insert(&**address, &account.rlp())?;
+			}
+		}
+
+		trace!(target: "spec", "ensure_db_good: Populated sec trie; root is {}", root);
+		for (address, account) in self.genesis_state.get().iter() {
+			db.note_non_null_account(address);
+			account.insert_additional(&mut AccountDBMut::new(db.as_hashdb_mut(), address), &factories.trie);
+		}
+
+		// Execute contract constructors.
+		let env_info = EnvInfo {
+			number: 0,
+			author: self.author,
+			timestamp: self.timestamp,
+			difficulty: self.difficulty,
+			last_hashes: Default::default(),
+			gas_used: U256::zero(),
+			gas_limit: U256::max_value(),
+		};
+		let from = Address::default();
+		let start_nonce = self.engine.account_start_nonce();
+
+		let mut state = State::from_existing(db, root, start_nonce, factories.clone())?;
+		// Mutate the state with each constructor.
+		for &(ref address, ref constructor) in self.constructors.iter() {
+			trace!(target: "spec", "ensure_db_good: Creating a contract at {}.", address);
+			let params = ActionParams {
+				code_address: address.clone(),
+				code_hash: constructor.sha3(),
+				address: address.clone(),
+				sender: from.clone(),
+				origin: from.clone(),
+				gas: U256::max_value(),
+				gas_price: Default::default(),
+				value: ActionValue::Transfer(Default::default()),
+				code: Some(Arc::new(constructor.clone())),
+				data: None,
+				call_type: CallType::None,
+			};
+			let mut substate = Substate::new();
 			{
-				let mut t = factory.create(db.as_hashdb_mut(), &mut root);
+				let mut exec = Executive::new(&mut state, &env_info, self.engine.as_ref(), &factories.vm);
-				for (address, account) in self.genesis_state.get().iter() {
+				if let Err(e) = exec.create(params, &mut substate, &mut NoopTracer, &mut NoopVMTracer) {
-					try!(t.insert(&**address, &account.rlp()));
+					warn!(target: "spec", "Genesis constructor execution at {} failed: {}.", address, e);
 				}
 			}
-			trace!(target: "spec", "ensure_db_good: Populated sec trie; root is {}", root);
+			if let Err(e) = state.commit() {
-			for (address, account) in self.genesis_state.get().iter() {
+				warn!(target: "spec", "Genesis constructor trie commit at {} failed: {}.", address, e);
-				db.note_non_null_account(address);
-				account.insert_additional(&mut AccountDBMut::new(db.as_hashdb_mut(), address), factory);
 			}
-			assert!(db.as_hashdb().contains(&self.state_root()));
+		}
-			Ok(true)
+		let (root, db) = state.drop();
-		} else { Ok(false) }
+
+		*self.state_root_memo.write() = Some(root);
+		Ok(db)
 	}
 
 	/// Loads spec from json file.
@@ -273,6 +330,9 @@ impl Spec {
 	/// Create a new Spec which is a NullEngine consensus with a premine of address whose secret is sha3('').
 	pub fn new_null() -> Spec { load_bundled!("null") }
 
+	/// Create a new Spec which constructs a contract at address 5 with storage at 0 equal to 1.
+	pub fn new_test_constructor() -> Spec { load_bundled!("constructor") }
+
 	/// Create a new Spec with InstantSeal consensus which does internal sealing (not requiring work).
 	pub fn new_instant() -> Spec { load_bundled!("instant_seal") }
 
@@ -287,10 +347,10 @@ impl Spec {
 
 #[cfg(test)]
 mod tests {
-	use std::str::FromStr;
+	use util::*;
-	use util::hash::*;
-	use util::sha3::*;
 	use views::*;
+	use tests::helpers::get_temp_state_db;
+	use state::State;
 	use super::*;
 
 	// https://github.com/ethcore/parity/issues/1840
@@ -307,4 +367,14 @@ mod tests {
 		let genesis = test_spec.genesis_block();
 		assert_eq!(BlockView::new(&genesis).header_view().sha3(), H256::from_str("0cd786a2425d16f152c658316c423e6ce1181e15c3295826d7c9904cba9ce303").unwrap());
 	}
+
+	#[test]
+	fn genesis_constructor() {
+		let spec = Spec::new_test_constructor();
+		let mut db_result = get_temp_state_db();
+		let db = spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
+		let state = State::from_existing(db.boxed_clone(), spec.state_root(), spec.engine.account_start_nonce(), Default::default()).unwrap();
+		let expected = H256::from_str("0000000000000000000000000000000000000000000000000000000000000001").unwrap();
+		assert_eq!(state.storage_at(&Address::from_str("0000000000000000000000000000000000000005").unwrap(), &H256::zero()), expected);
+	}
 }

ethcore/src/state/account.rs

@@ -450,8 +450,8 @@ impl Account {
 
 		let mut recorder = TrieRecorder::with_depth(from_level);
 
-		let trie = try!(TrieDB::new(db, &self.storage_root));
+		let trie = TrieDB::new(db, &self.storage_root)?;
-		let _ = try!(trie.get_recorded(&storage_key, &mut recorder));
+		let _ = trie.get_recorded(&storage_key, &mut recorder)?;
 
 		Ok(recorder.drain().into_iter().map(|r| r.data).collect())
 	}

ethcore/src/state/mod.rs

@@ -515,11 +515,11 @@ impl State {
 
 		let options = TransactOptions { tracing: tracing, vm_tracing: false, check_nonce: true };
 		let vm_factory = self.factories.vm.clone();
-		let e = try!(Executive::new(self, env_info, engine, &vm_factory).transact(t, options));
+		let e = Executive::new(self, env_info, engine, &vm_factory).transact(t, options)?;
 
 		// TODO uncomment once to_pod() works correctly.
 //		trace!("Applied transaction. Diff:\n{}\n", state_diff::diff_pod(&old, &self.to_pod()));
-		try!(self.commit());
+		self.commit()?;
 		let receipt = Receipt::new(self.root().clone(), e.cumulative_gas_used, e.logs);
 		trace!(target: "state", "Transaction receipt: {:?}", receipt);
 		Ok(ApplyOutcome{receipt: receipt, trace: e.trace})
@@ -551,15 +551,15 @@ impl State {
 		}
 
 		{
-			let mut trie = try!(factories.trie.from_existing(db.as_hashdb_mut(), root));
+			let mut trie = factories.trie.from_existing(db.as_hashdb_mut(), root)?;
 			for (address, ref mut a) in accounts.iter_mut().filter(|&(_, ref a)| a.is_dirty()) {
 				a.state = AccountState::Committed;
 				match a.account {
 					Some(ref mut account) => {
-						try!(trie.insert(address, &account.rlp()));
+						trie.insert(address, &account.rlp())?;
 					},
 					None => {
-						try!(trie.remove(address));
+						trie.remove(address)?;
 					},
 				}
 			}
@@ -771,8 +771,8 @@ impl State {
 	/// `account_key` == sha3(address)
 	pub fn prove_account(&self, account_key: H256, from_level: u32) -> Result<Vec<Bytes>, Box<TrieError>> {
 		let mut recorder = TrieRecorder::with_depth(from_level);
-		let trie = try!(TrieDB::new(self.db.as_hashdb(), &self.root));
+		let trie = TrieDB::new(self.db.as_hashdb(), &self.root)?;
-		let _  = try!(trie.get_recorded(&account_key, &mut recorder));
+		let _  = trie.get_recorded(&account_key, &mut recorder)?;
 
 		Ok(recorder.drain().into_iter().map(|r| r.data).collect())
 	}
@@ -785,8 +785,8 @@ impl State {
 	pub fn prove_storage(&self, account_key: H256, storage_key: H256, from_level: u32) -> Result<Vec<Bytes>, Box<TrieError>> {
 		// TODO: probably could look into cache somehow but it's keyed by
 		// address, not sha3(address).
-		let trie = try!(TrieDB::new(self.db.as_hashdb(), &self.root));
+		let trie = TrieDB::new(self.db.as_hashdb(), &self.root)?;
-		let acc = match try!(trie.get(&account_key)) {
+		let acc = match trie.get(&account_key)? {
 			Some(rlp) => Account::from_rlp(&rlp),
 			None => return Ok(Vec::new()),
 		};
@@ -798,8 +798,8 @@ impl State {
 	/// Get code by address hash.
 	/// Only works when backed by a secure trie.
 	pub fn code_by_address_hash(&self, account_key: H256) -> Result<Option<Bytes>, Box<TrieError>> {
-		let trie = try!(TrieDB::new(self.db.as_hashdb(), &self.root));
+		let trie = TrieDB::new(self.db.as_hashdb(), &self.root)?;
-		let mut acc = match try!(trie.get(&account_key)) {
+		let mut acc = match trie.get(&account_key)? {
 			Some(rlp) => Account::from_rlp(&rlp),
 			None => return Ok(None),
 		};

ethcore/src/state_db.rs

@@ -195,9 +195,9 @@ impl StateDB {
 	pub fn journal_under(&mut self, batch: &mut DBTransaction, now: u64, id: &H256) -> Result<u32, UtilError> {
 		{
  			let mut bloom_lock = self.account_bloom.lock();
- 			try!(Self::commit_bloom(batch, bloom_lock.drain_journal()));
+ 			Self::commit_bloom(batch, bloom_lock.drain_journal())?;
  		}
-		let records = try!(self.db.journal_under(batch, now, id));
+		let records = self.db.journal_under(batch, now, id)?;
 		self.commit_hash = Some(id.clone());
 		self.commit_number = Some(now);
 		Ok(records)

ethcore/src/tests/client.rs

@@ -24,7 +24,7 @@ use types::filter::Filter;
 use util::*;
 use devtools::*;
 use miner::Miner;
-use rlp::{Rlp, View};
+use rlp::View;
 use spec::Spec;
 use views::BlockView;
 use util::stats::Histogram;
@@ -103,7 +103,7 @@ fn imports_good_block() {
 	client.import_verified_blocks();
 
 	let block = client.block_header(BlockId::Number(1)).unwrap();
-	assert!(!block.is_empty());
+	assert!(!block.into_inner().is_empty());
 }
 
 #[test]
@@ -128,7 +128,7 @@ fn query_none_block() {
 fn query_bad_block() {
 	let client_result = get_test_client_with_blocks(vec![get_bad_state_dummy_block()]);
 	let client = client_result.reference();
-	let bad_block:Option<Bytes> = client.block_header(BlockId::Number(1));
+	let bad_block: Option<_> = client.block_header(BlockId::Number(1));
 
 	assert!(bad_block.is_none());
 }
@@ -180,7 +180,7 @@ fn returns_block_body() {
 	let client = client_result.reference();
 	let block = BlockView::new(&dummy_block);
 	let body = client.block_body(BlockId::Hash(block.header().hash())).unwrap();
-	let body = Rlp::new(&body);
+	let body = body.rlp();
 	assert_eq!(body.item_count(), 2);
 	assert_eq!(body.at(0).as_raw()[..], block.rlp().at(1).as_raw()[..]);
 	assert_eq!(body.at(1).as_raw()[..], block.rlp().at(2).as_raw()[..]);
@@ -192,7 +192,7 @@ fn imports_block_sequence() {
 	let client = client_result.reference();
 	let block = client.block_header(BlockId::Number(5)).unwrap();
 
-	assert!(!block.is_empty());
+	assert!(!block.into_inner().is_empty());
 }
 
 #[test]

ethcore/src/tests/helpers.rs

@@ -18,7 +18,6 @@ use ethkey::KeyPair;
 use io::*;
 use client::{BlockChainClient, Client, ClientConfig};
 use util::*;
-use util::trie::TrieSpec;
 use spec::*;
 use state_db::StateDB;
 use block::{OpenBlock, Drain};
@@ -157,8 +156,7 @@ pub fn generate_dummy_client_with_spec_and_data<F>(get_test_spec: F, block_numbe
 	let test_engine = &*test_spec.engine;
 
 	let mut db_result = get_temp_state_db();
-	let mut db = db_result.take();
+	let mut db = test_spec.ensure_db_good(db_result.take(), &Default::default()).unwrap();
-	test_spec.ensure_db_good(&mut db, &TrieFactory::new(TrieSpec::Secure)).unwrap();
 	let genesis_header = test_spec.genesis_header();
 
 	let mut rolling_timestamp = 40;

ethcore/src/trace/bloom.rs

@@ -73,7 +73,7 @@ impl Encodable for BlockTracesBloom {
 
 impl Decodable for BlockTracesBloomGroup {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		let blooms = try!(Decodable::decode(decoder));
+		let blooms = Decodable::decode(decoder)?;
 		let group = BlockTracesBloomGroup {
 			blooms: blooms
 		};

ethcore/src/types/account_diff.rs

@@ -80,9 +80,9 @@ pub enum Existance {
 impl fmt::Display for Existance {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		match *self {
-			Existance::Born => try!(write!(f, "+++")),
+			Existance::Born => write!(f, "+++")?,
-			Existance::Alive => try!(write!(f, "***")),
+			Existance::Alive => write!(f, "***")?,
-			Existance::Died => try!(write!(f, "XXX")),
+			Existance::Died => write!(f, "XXX")?,
 		}
 		Ok(())
 	}
@@ -117,24 +117,24 @@ impl fmt::Display for AccountDiff {
 		use util::bytes::ToPretty;
 
 		match self.nonce {
-			Diff::Born(ref x) => try!(write!(f, "  non {}", x)),
+			Diff::Born(ref x) => write!(f, "  non {}", x)?,
-			Diff::Changed(ref pre, ref post) => try!(write!(f, "#{} ({} {} {})", post, pre, if pre > post {"-"} else {"+"}, *max(pre, post) - *	min(pre, post))),
+			Diff::Changed(ref pre, ref post) => write!(f, "#{} ({} {} {})", post, pre, if pre > post {"-"} else {"+"}, *max(pre, post) - *	min(pre, post))?,
 			_ => {},
 		}
 		match self.balance {
-			Diff::Born(ref x) => try!(write!(f, "  bal {}", x)),
+			Diff::Born(ref x) => write!(f, "  bal {}", x)?,
-			Diff::Changed(ref pre, ref post) => try!(write!(f, "${} ({} {} {})", post, pre, if pre > post {"-"} else {"+"}, *max(pre, post) - *min(pre, post))),
+			Diff::Changed(ref pre, ref post) => write!(f, "${} ({} {} {})", post, pre, if pre > post {"-"} else {"+"}, *max(pre, post) - *min(pre, post))?,
 			_ => {},
 		}
 		if let Diff::Born(ref x) = self.code {
-			try!(write!(f, "  code {}", x.pretty()));
+			write!(f, "  code {}", x.pretty())?;
 		}
-		try!(write!(f, "\n"));
+		write!(f, "\n")?;
 		for (k, dv) in &self.storage {
 			match *dv {
-				Diff::Born(ref v) => try!(write!(f, "    +  {} => {}\n", interpreted_hash(k), interpreted_hash(v))),
+				Diff::Born(ref v) => write!(f, "    +  {} => {}\n", interpreted_hash(k), interpreted_hash(v))?,
-				Diff::Changed(ref pre, ref post) => try!(write!(f, "    *  {} => {} (was {})\n", interpreted_hash(k), interpreted_hash(post), interpreted_hash(pre))),
+				Diff::Changed(ref pre, ref post) => write!(f, "    *  {} => {} (was {})\n", interpreted_hash(k), interpreted_hash(post), interpreted_hash(pre))?,
-				Diff::Died(_) => try!(write!(f, "    X  {}\n", interpreted_hash(k))),
+				Diff::Died(_) => write!(f, "    X  {}\n", interpreted_hash(k))?,
 				_ => {},
 			}
 		}

ethcore/src/types/encoded.rs

@@ -0,0 +1,273 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Lazily-decoded owning views of RLP-encoded blockchain objects.
+//! These views are meant to contain _trusted_ data -- without encoding
+//! errors or inconsistencies.
+//!
+//! In general these views are useful when only a few fields of an object
+//! are relevant. In these cases it's more efficient to decode the object piecemeal.
+//! When the entirety of the object is needed, it's better to upgrade it to a fully
+//! decoded object where parts like the hash can be saved.
+
+use block::Block as FullBlock;
+use header::{BlockNumber, Header as FullHeader};
+use transaction::SignedTransaction;
+use views;
+
+use util::{Address, Hashable, H256, H2048, U256};
+use rlp::{Rlp, View};
+
+/// Owning header view.
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "ipc", binary)]
+pub struct Header(Vec<u8>);
+
+impl Header {
+	/// Create a new owning header view.
+	/// Expects the data to be an RLP-encoded header -- any other case will likely lead to
+	/// panics further down the line.
+	pub fn new(encoded: Vec<u8>) -> Self { Header(encoded) }
+
+	/// Upgrade this encoded view to a fully owned `Header` object.
+	pub fn decode(&self) -> FullHeader { ::rlp::decode(&self.0) }
+
+	/// Get a borrowed header view onto the data.
+	#[inline]
+	pub fn view(&self) -> views::HeaderView { views::HeaderView::new(&self.0) }
+
+	/// Get the rlp of the header.
+	#[inline]
+	pub fn rlp(&self) -> Rlp { Rlp::new(&self.0) }
+
+	/// Consume the view and return the raw bytes.
+	pub fn into_inner(self) -> Vec<u8> { self.0 }
+}
+
+// forwarders to borrowed view.
+impl Header {
+	/// Returns the header hash.
+	pub fn hash(&self) -> H256 { self.sha3() }
+
+	/// Returns the parent hash.
+	pub fn parent_hash(&self) -> H256 { self.view().parent_hash() }
+
+	/// Returns the uncles hash.
+	pub fn uncles_hash(&self) -> H256 { self.view().uncles_hash() }
+
+	/// Returns the author.
+	pub fn author(&self) -> Address { self.view().author() }
+
+	/// Returns the state root.
+	pub fn state_root(&self) -> H256 { self.view().state_root() }
+
+	/// Returns the transaction trie root.
+	pub fn transactions_root(&self) -> H256 { self.view().transactions_root() }
+
+	/// Returns the receipts trie root
+	pub fn receipts_root(&self) -> H256 { self.view().receipts_root() }
+
+	/// Returns the block log bloom
+	pub fn log_bloom(&self) -> H2048 { self.view().log_bloom() }
+
+	/// Difficulty of this block
+	pub fn difficulty(&self) -> U256 { self.view().difficulty() }
+
+	/// Number of this block.
+	pub fn number(&self) -> BlockNumber { self.view().number() }
+
+	/// Time this block was produced.
+	pub fn timestamp(&self) -> u64 { self.view().timestamp() }
+
+	/// Gas limit of this block.
+	pub fn gas_limit(&self) -> U256 { self.view().gas_limit() }
+
+	/// Total gas used in this block.
+	pub fn gas_used(&self) -> U256 { self.view().gas_used() }
+
+	/// Block extra data.
+	pub fn extra_data(&self) -> Vec<u8> { self.view().extra_data() }
+
+	/// Engine-specific seal fields.
+	pub fn seal(&self) -> Vec<Vec<u8>> { self.view().seal() }
+}
+
+impl Hashable for Header {
+	fn sha3(&self) -> H256 {
+		self.0.sha3()
+	}
+}
+
+/// Owning block body view.
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "ipc", binary)]
+pub struct Body(Vec<u8>);
+
+impl Body {
+	/// Create a new owning block body view. The raw bytes passed in must be an rlp-encoded block
+	/// body.
+	pub fn new(raw: Vec<u8>) -> Self { Body(raw) }
+
+	/// Get a borrowed view of the data within.
+	#[inline]
+	pub fn view(&self) -> views::BodyView { views::BodyView::new(&self.0) }
+
+	/// Fully decode this block body.
+	pub fn decode(&self) -> (Vec<SignedTransaction>, Vec<FullHeader>) {
+		(self.view().transactions(), self.view().uncles())
+	}
+
+	/// Get the RLP of this block body.
+	#[inline]
+	pub fn rlp(&self) -> Rlp {
+		Rlp::new(&self.0)
+	}
+
+	/// Consume the view and return the raw bytes.
+	pub fn into_inner(self) -> Vec<u8> { self.0 }
+}
+
+// forwarders to borrowed view.
+impl Body {
+	/// Get a vector of all transactions.
+	pub fn transactions(&self) -> Vec<SignedTransaction> { self.view().transactions() }
+
+	/// Number of transactions in the block.
+	pub fn transactions_count(&self) -> usize { self.view().transactions_count() }
+
+	/// A view over each transaction in the block.
+	pub fn transaction_views(&self) -> Vec<views::TransactionView> { self.view().transaction_views() }
+
+	/// The hash of each transaction in the block.
+	pub fn transaction_hashes(&self) -> Vec<H256> { self.view().transaction_hashes() }
+
+	/// Decode uncle headers.
+	pub fn uncles(&self) -> Vec<FullHeader> { self.view().uncles() }
+
+	/// Number of uncles.
+	pub fn uncles_count(&self) -> usize { self.view().uncles_count() }
+
+	/// Borrowed view over each uncle.
+	pub fn uncle_views(&self) -> Vec<views::HeaderView> { self.view().uncle_views() }
+
+	/// Hash of each uncle.
+	pub fn uncle_hashes(&self) -> Vec<H256> { self.view().uncle_hashes() }
+}
+
+/// Owning block view.
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "ipc", binary)]
+pub struct Block(Vec<u8>);
+
+impl Block {
+	/// Create a new owning block view. The raw bytes passed in must be an rlp-encoded block.
+	pub fn new(raw: Vec<u8>) -> Self { Block(raw) }
+
+	/// Get a borrowed view of the whole block.
+	#[inline]
+	pub fn view(&self) -> views::BlockView { views::BlockView::new(&self.0) }
+
+	/// Get a borrowed view of the block header.
+	#[inline]
+	pub fn header_view(&self) -> views::HeaderView { self.view().header_view() }
+
+	/// Decode to a full block.
+	pub fn decode(&self) -> FullBlock { ::rlp::decode(&self.0) }
+
+	/// Get the rlp of this block.
+	#[inline]
+	pub fn rlp(&self) -> Rlp {
+		Rlp::new(&self.0)
+	}
+
+	/// Consume the view and return the raw bytes.
+	pub fn into_inner(self) -> Vec<u8> { self.0 }
+}
+
+// forwarders to borrowed header view.
+impl Block {
+	/// Returns the header hash.
+	pub fn hash(&self) -> H256 { self.header_view().sha3() }
+
+	/// Returns the parent hash.
+	pub fn parent_hash(&self) -> H256 { self.header_view().parent_hash() }
+
+	/// Returns the uncles hash.
+	pub fn uncles_hash(&self) -> H256 { self.header_view().uncles_hash() }
+
+	/// Returns the author.
+	pub fn author(&self) -> Address { self.header_view().author() }
+
+	/// Returns the state root.
+	pub fn state_root(&self) -> H256 { self.header_view().state_root() }
+
+	/// Returns the transaction trie root.
+	pub fn transactions_root(&self) -> H256 { self.header_view().transactions_root() }
+
+	/// Returns the receipts trie root
+	pub fn receipts_root(&self) -> H256 { self.header_view().receipts_root() }
+
+	/// Returns the block log bloom
+	pub fn log_bloom(&self) -> H2048 { self.header_view().log_bloom() }
+
+	/// Difficulty of this block
+	pub fn difficulty(&self) -> U256 { self.header_view().difficulty() }
+
+	/// Number of this block.
+	pub fn number(&self) -> BlockNumber { self.header_view().number() }
+
+	/// Time this block was produced.
+	pub fn timestamp(&self) -> u64 { self.header_view().timestamp() }
+
+	/// Gas limit of this block.
+	pub fn gas_limit(&self) -> U256 { self.header_view().gas_limit() }
+
+	/// Total gas used in this block.
+	pub fn gas_used(&self) -> U256 { self.header_view().gas_used() }
+
+	/// Block extra data.
+	pub fn extra_data(&self) -> Vec<u8> { self.header_view().extra_data() }
+
+	/// Engine-specific seal fields.
+	pub fn seal(&self) -> Vec<Vec<u8>> { self.header_view().seal() }
+}
+
+// forwarders to body view.
+impl Block {
+	/// Get a vector of all transactions.
+	pub fn transactions(&self) -> Vec<SignedTransaction> { self.view().transactions() }
+
+	/// Number of transactions in the block.
+	pub fn transactions_count(&self) -> usize { self.view().transactions_count() }
+
+	/// A view over each transaction in the block.
+	pub fn transaction_views(&self) -> Vec<views::TransactionView> { self.view().transaction_views() }
+
+	/// The hash of each transaction in the block.
+	pub fn transaction_hashes(&self) -> Vec<H256> { self.view().transaction_hashes() }
+
+	/// Decode uncle headers.
+	pub fn uncles(&self) -> Vec<FullHeader> { self.view().uncles() }
+
+	/// Number of uncles.
+	pub fn uncles_count(&self) -> usize { self.view().uncles_count() }
+
+	/// Borrowed view over each uncle.
+	pub fn uncle_views(&self) -> Vec<views::HeaderView> { self.view().uncle_views() }
+
+	/// Hash of each uncle.
+	pub fn uncle_hashes(&self) -> Vec<H256> { self.view().uncle_hashes() }
+}

ethcore/src/types/log_entry.rs

@@ -50,9 +50,9 @@ impl Decodable for LogEntry {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let entry = LogEntry {
-			address: try!(d.val_at(0)),
+			address: d.val_at(0)?,
-			topics: try!(d.val_at(1)),
+			topics: d.val_at(1)?,
-			data: try!(d.val_at(2)),
+			data: d.val_at(2)?,
 		};
 		Ok(entry)
 	}

ethcore/src/types/mod.rs.in

@@ -36,3 +36,4 @@ pub mod snapshot_manifest;
 pub mod mode;
 pub mod pruning_info;
 pub mod security_level;
+pub mod encoded;

ethcore/src/types/pruning_info.rs

@@ -28,4 +28,6 @@ pub struct PruningInfo {
 	pub earliest_chain: u64,
 	/// The first block where state requests may be served.
 	pub earliest_state: u64,
+	/// State pruning history size.
+	pub state_history_size: Option<u64>,
 }

ethcore/src/types/receipt.rs

@@ -64,10 +64,10 @@ impl Decodable for Receipt {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let receipt = Receipt {
-			state_root: try!(d.val_at(0)),
+			state_root: d.val_at(0)?,
-			gas_used: try!(d.val_at(1)),
+			gas_used: d.val_at(1)?,
-			log_bloom: try!(d.val_at(2)),
+			log_bloom: d.val_at(2)?,
-			logs: try!(d.val_at(3)),
+			logs: d.val_at(3)?,
 		};
 		Ok(receipt)
 	}

ethcore/src/types/snapshot_manifest.rs

@@ -53,11 +53,11 @@ impl ManifestData {
 	pub fn from_rlp(raw: &[u8]) -> Result<Self, DecoderError> {
 		let decoder = UntrustedRlp::new(raw);
 
-		let state_hashes: Vec<H256> = try!(decoder.val_at(0));
+		let state_hashes: Vec<H256> = decoder.val_at(0)?;
-		let block_hashes: Vec<H256> = try!(decoder.val_at(1));
+		let block_hashes: Vec<H256> = decoder.val_at(1)?;
-		let state_root: H256 = try!(decoder.val_at(2));
+		let state_root: H256 = decoder.val_at(2)?;
-		let block_number: u64 = try!(decoder.val_at(3));
+		let block_number: u64 = decoder.val_at(3)?;
-		let block_hash: H256 = try!(decoder.val_at(4));
+		let block_hash: H256 = decoder.val_at(4)?;
 
 		Ok(ManifestData {
 			state_hashes: state_hashes,

ethcore/src/types/state_diff.rs

@@ -41,7 +41,7 @@ impl StateDiff {
 impl fmt::Display for StateDiff {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		for (add, acc) in &self.raw {
-			try!(write!(f, "{} {}: {}", acc.existance(), add, acc));
+			write!(f, "{} {}: {}", acc.existance(), add, acc)?;
 		}
 		Ok(())
 	}

ethcore/src/types/trace_types/error.rs

@@ -86,7 +86,7 @@ impl Encodable for Error {
 impl Decodable for Error {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		use self::Error::*;
-		let value: u8 = try!(decoder.as_rlp().as_val());
+		let value: u8 = decoder.as_rlp().as_val()?;
 		match value {
 			0 => Ok(OutOfGas),
 			1 => Ok(BadJumpDestination),

ethcore/src/types/trace_types/flat.rs

@@ -66,11 +66,11 @@ impl Encodable for FlatTrace {
 impl Decodable for FlatTrace {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
-		let v: Vec<usize> = try!(d.val_at(3));
+		let v: Vec<usize> = d.val_at(3)?;
 		let res = FlatTrace {
-			action: try!(d.val_at(0)),
+			action: d.val_at(0)?,
-			result: try!(d.val_at(1)),
+			result: d.val_at(1)?,
-			subtraces: try!(d.val_at(2)),
+			subtraces: d.val_at(2)?,
 			trace_address: v.into_iter().collect(),
 		};
 
@@ -109,7 +109,7 @@ impl Encodable for FlatTransactionTraces {
 
 impl Decodable for FlatTransactionTraces {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		Ok(FlatTransactionTraces(try!(Decodable::decode(decoder))))
+		Ok(FlatTransactionTraces(Decodable::decode(decoder)?))
 	}
 }
 
@@ -150,7 +150,7 @@ impl Encodable for FlatBlockTraces {
 
 impl Decodable for FlatBlockTraces {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
-		Ok(FlatBlockTraces(try!(Decodable::decode(decoder))))
+		Ok(FlatBlockTraces(Decodable::decode(decoder)?))
 	}
 }
 

ethcore/src/types/trace_types/trace.rs

@@ -48,8 +48,8 @@ impl Decodable for CallResult {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let res = CallResult {
-			gas_used: try!(d.val_at(0)),
+			gas_used: d.val_at(0)?,
-			output: try!(d.val_at(1)),
+			output: d.val_at(1)?,
 		};
 
 		Ok(res)
@@ -81,9 +81,9 @@ impl Decodable for CreateResult {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let res = CreateResult {
-			gas_used: try!(d.val_at(0)),
+			gas_used: d.val_at(0)?,
-			code: try!(d.val_at(1)),
+			code: d.val_at(1)?,
-			address: try!(d.val_at(2)),
+			address: d.val_at(2)?,
 		};
 
 		Ok(res)
@@ -144,12 +144,12 @@ impl Decodable for Call {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let res = Call {
-			from: try!(d.val_at(0)),
+			from: d.val_at(0)?,
-			to: try!(d.val_at(1)),
+			to: d.val_at(1)?,
-			value: try!(d.val_at(2)),
+			value: d.val_at(2)?,
-			gas: try!(d.val_at(3)),
+			gas: d.val_at(3)?,
-			input: try!(d.val_at(4)),
+			input: d.val_at(4)?,
-			call_type: try!(d.val_at(5)),
+			call_type: d.val_at(5)?,
 		};
 
 		Ok(res)
@@ -204,10 +204,10 @@ impl Decodable for Create {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let res = Create {
-			from: try!(d.val_at(0)),
+			from: d.val_at(0)?,
-			value: try!(d.val_at(1)),
+			value: d.val_at(1)?,
-			gas: try!(d.val_at(2)),
+			gas: d.val_at(2)?,
-			init: try!(d.val_at(3)),
+			init: d.val_at(3)?,
 		};
 
 		Ok(res)
@@ -255,9 +255,9 @@ impl Decodable for Suicide {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let res = Suicide {
-			address: try!(d.val_at(0)),
+			address: d.val_at(0)?,
-			refund_address: try!(d.val_at(1)),
+			refund_address: d.val_at(1)?,
-			balance: try!(d.val_at(2)),
+			balance: d.val_at(2)?,
 		};
 
 		Ok(res)
@@ -300,7 +300,7 @@ impl Encodable for Action {
 impl Decodable for Action {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
-		let action_type: u8 = try!(d.val_at(0));
+		let action_type: u8 = d.val_at(0)?;
 		match action_type {
 			0 => d.val_at(1).map(Action::Call),
 			1 => d.val_at(1).map(Action::Create),
@@ -371,7 +371,7 @@ impl Encodable for Res {
 impl Decodable for Res {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
-		let action_type: u8 = try!(d.val_at(0));
+		let action_type: u8 = d.val_at(0)?;
 		match action_type {
 			0 => d.val_at(1).map(Res::Call),
 			1 => d.val_at(1).map(Res::Create),
@@ -415,8 +415,8 @@ impl Decodable for MemoryDiff {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		Ok(MemoryDiff {
-			offset: try!(d.val_at(0)),
+			offset: d.val_at(0)?,
-			data: try!(d.val_at(1)),
+			data: d.val_at(1)?,
 		})
 	}
 }
@@ -443,8 +443,8 @@ impl Decodable for StorageDiff {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		Ok(StorageDiff {
-			location: try!(d.val_at(0)),
+			location: d.val_at(0)?,
-			value: try!(d.val_at(1)),
+			value: d.val_at(1)?,
 		})
 	}
 }
@@ -477,10 +477,10 @@ impl Decodable for VMExecutedOperation {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		Ok(VMExecutedOperation {
-			gas_used: try!(d.val_at(0)),
+			gas_used: d.val_at(0)?,
-			stack_push: try!(d.val_at(1)),
+			stack_push: d.val_at(1)?,
-			mem_diff: try!(d.val_at(2)),
+			mem_diff: d.val_at(2)?,
-			store_diff: try!(d.val_at(3)),
+			store_diff: d.val_at(3)?,
 		})
 	}
 }
@@ -513,10 +513,10 @@ impl Decodable for VMOperation {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let res = VMOperation {
-			pc: try!(d.val_at(0)),
+			pc: d.val_at(0)?,
-			instruction: try!(d.val_at(1)),
+			instruction: d.val_at(1)?,
-			gas_cost: try!(d.val_at(2)),
+			gas_cost: d.val_at(2)?,
-			executed: try!(d.val_at(3)),
+			executed: d.val_at(3)?,
 		};
 
 		Ok(res)
@@ -552,10 +552,10 @@ impl Decodable for VMTrace {
 	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = decoder.as_rlp();
 		let res = VMTrace {
-			parent_step: try!(d.val_at(0)),
+			parent_step: d.val_at(0)?,
-			code: try!(d.val_at(1)),
+			code: d.val_at(1)?,
-			operations: try!(d.val_at(2)),
+			operations: d.val_at(2)?,
-			subs: try!(d.val_at(3)),
+			subs: d.val_at(3)?,
 		};
 
 		Ok(res)

ethcore/src/types/transaction.rs

@@ -48,7 +48,7 @@ impl Decodable for Action {
 		if rlp.is_empty() {
 			Ok(Action::Create)
 		} else {
-			Ok(Action::Call(try!(rlp.as_val())))
+			Ok(Action::Call(rlp.as_val()?))
 		}
 	}
 }
@@ -247,16 +247,16 @@ impl Decodable for SignedTransaction {
 		}
 		Ok(SignedTransaction {
 			unsigned: Transaction {
-				nonce: try!(d.val_at(0)),
+				nonce: d.val_at(0)?,
-				gas_price: try!(d.val_at(1)),
+				gas_price: d.val_at(1)?,
-				gas: try!(d.val_at(2)),
+				gas: d.val_at(2)?,
-				action: try!(d.val_at(3)),
+				action: d.val_at(3)?,
-				value: try!(d.val_at(4)),
+				value: d.val_at(4)?,
-				data: try!(d.val_at(5)),
+				data: d.val_at(5)?,
 			},
-			v: try!(d.val_at(6)),
+			v: d.val_at(6)?,
-			r: try!(d.val_at(7)),
+			r: d.val_at(7)?,
-			s: try!(d.val_at(8)),
+			s: d.val_at(8)?,
 			hash: Cell::new(None),
 			sender: Cell::new(None),
 		})
@@ -338,7 +338,7 @@ impl SignedTransaction {
 		match sender {
 			Some(s) => Ok(s),
 			None => {
-				let s = public_to_address(&try!(self.public_key()));
+				let s = public_to_address(&self.public_key()?);
 				self.sender.set(Some(s));
 				Ok(s)
 			}
@@ -347,7 +347,7 @@ impl SignedTransaction {
 
 	/// Returns the public key of the sender.
 	pub fn public_key(&self) -> Result<Public, Error> {
-		Ok(try!(recover(&self.signature(), &self.unsigned.hash(self.network_id()))))
+		Ok(recover(&self.signature(), &self.unsigned.hash(self.network_id()))?)
 	}
 
 	/// Do basic validation, checking for valid signature and minimum gas,
@@ -363,7 +363,7 @@ impl SignedTransaction {
 			Some(1) if allow_network_id_of_one => {},
 			_ => return Err(TransactionError::InvalidNetworkId.into()),
 		}
-		try!(self.sender());
+		self.sender()?;
 		if self.gas < U256::from(self.gas_required(&schedule)) {
 			Err(TransactionError::InvalidGasLimit(::util::OutOfBounds{min: Some(U256::from(self.gas_required(&schedule))), max: None, found: self.gas}).into())
 		} else {

ethcore/src/verification/queue/kind.rs

@@ -19,18 +19,21 @@
 use engines::Engine;
 use error::Error;
 
-use util::{HeapSizeOf, H256};
+use util::{HeapSizeOf, H256, U256};
 
 pub use self::blocks::Blocks;
 pub use self::headers::Headers;
 
 /// Something which can produce a hash and a parent hash.
-pub trait HasHash {
+pub trait BlockLike {
 	/// Get the hash of this item.
 	fn hash(&self) -> H256;
 
 	/// Get the hash of this item's parent.
 	fn parent_hash(&self) -> H256;
+
+	/// Get the difficulty of this item.
+	fn difficulty(&self) -> U256;
 }
 
 /// Defines transitions between stages of verification.
@@ -45,13 +48,13 @@ pub trait HasHash {
 /// consistent.
 pub trait Kind: 'static + Sized + Send + Sync {
 	/// The first stage: completely unverified.
-	type Input: Sized + Send + HasHash + HeapSizeOf;
+	type Input: Sized + Send + BlockLike + HeapSizeOf;
 
 	/// The second stage: partially verified.
-	type Unverified: Sized + Send + HasHash + HeapSizeOf;
+	type Unverified: Sized + Send + BlockLike + HeapSizeOf;
 
 	/// The third stage: completely verified.
-	type Verified: Sized + Send + HasHash + HeapSizeOf;
+	type Verified: Sized + Send + BlockLike + HeapSizeOf;
 
 	/// Attempt to create the `Unverified` item from the input.
 	fn create(input: Self::Input, engine: &Engine) -> Result<Self::Unverified, Error>;
@@ -62,14 +65,14 @@ pub trait Kind: 'static + Sized + Send + Sync {
 
 /// The blocks verification module.
 pub mod blocks {
-	use super::{Kind, HasHash};
+	use super::{Kind, BlockLike};
 
 	use engines::Engine;
 	use error::Error;
 	use header::Header;
 	use verification::{PreverifiedBlock, verify_block_basic, verify_block_unordered};
 
-	use util::{Bytes, HeapSizeOf, H256};
+	use util::{Bytes, HeapSizeOf, H256, U256};
 
 	/// A mode for verifying blocks.
 	pub struct Blocks;
@@ -126,7 +129,7 @@ pub mod blocks {
 		}
 	}
 
-	impl HasHash for Unverified {
+	impl BlockLike for Unverified {
 		fn hash(&self) -> H256 {
 			self.header.hash()
 		}
@@ -134,9 +137,13 @@ pub mod blocks {
 		fn parent_hash(&self) -> H256 {
 			self.header.parent_hash().clone()
 		}
+
+		fn difficulty(&self) -> U256 {
+			self.header.difficulty().clone()
+		}
 	}
 
-	impl HasHash for PreverifiedBlock {
+	impl BlockLike for PreverifiedBlock {
 		fn hash(&self) -> H256 {
 			self.header.hash()
 		}
@@ -144,12 +151,16 @@ pub mod blocks {
 		fn parent_hash(&self) -> H256 {
 			self.header.parent_hash().clone()
 		}
+
+		fn difficulty(&self) -> U256 {
+			self.header.difficulty().clone()
+		}
 	}
 }
 
 /// Verification for headers.
 pub mod headers {
-	use super::{Kind, HasHash};
+	use super::{Kind, BlockLike};
 
 	use engines::Engine;
 	use error::Error;
@@ -157,10 +168,12 @@ pub mod headers {
 	use verification::verify_header_params;
 
 	use util::hash::H256;
+	use util::U256;
 
-	impl HasHash for Header {
+	impl BlockLike for Header {
 		fn hash(&self) -> H256 { self.hash() }
 		fn parent_hash(&self) -> H256 { self.parent_hash().clone() }
+		fn difficulty(&self) -> U256 { self.difficulty().clone() }
 	}
 
 	/// A mode for verifying headers.

ethcore/src/verification/queue/mod.rs

@@ -26,7 +26,7 @@ use error::*;
 use engines::Engine;
 use service::*;
 
-use self::kind::{HasHash, Kind};
+use self::kind::{BlockLike, Kind};
 
 pub use types::verification_queue_info::VerificationQueueInfo as QueueInfo;
 
@@ -132,13 +132,14 @@ pub struct VerificationQueue<K: Kind> {
 	deleting: Arc<AtomicBool>,
 	ready_signal: Arc<QueueSignal>,
 	empty: Arc<SCondvar>,
-	processing: RwLock<HashSet<H256>>,
+	processing: RwLock<HashMap<H256, U256>>, // hash to difficulty
 	ticks_since_adjustment: AtomicUsize,
 	max_queue_size: usize,
 	max_mem_use: usize,
 	scale_verifiers: bool,
 	verifier_handles: Vec<JoinHandle<()>>,
 	state: Arc<(Mutex<State>, Condvar)>,
+	total_difficulty: RwLock<U256>,
 }
 
 struct QueueSignal {
@@ -269,7 +270,7 @@ impl<K: Kind> VerificationQueue<K> {
 			more_to_verify: more_to_verify,
 			verification: verification,
 			deleting: deleting,
-			processing: RwLock::new(HashSet::new()),
+			processing: RwLock::new(HashMap::new()),
 			empty: empty,
 			ticks_since_adjustment: AtomicUsize::new(0),
 			max_queue_size: max(config.max_queue_size, MIN_QUEUE_LIMIT),
@@ -277,6 +278,7 @@ impl<K: Kind> VerificationQueue<K> {
 			scale_verifiers: scale_verifiers,
 			verifier_handles: verifier_handles,
 			state: state,
+			total_difficulty: RwLock::new(0.into()),
 		}
 	}
 
@@ -434,6 +436,7 @@ impl<K: Kind> VerificationQueue<K> {
 		sizes.unverified.store(0, AtomicOrdering::Release);
 		sizes.verifying.store(0, AtomicOrdering::Release);
 		sizes.verified.store(0, AtomicOrdering::Release);
+		*self.total_difficulty.write() = 0.into();
 
 		self.processing.write().clear();
 	}
@@ -448,7 +451,7 @@ impl<K: Kind> VerificationQueue<K> {
 
 	/// Check if the item is currently in the queue
 	pub fn status(&self, hash: &H256) -> Status {
-		if self.processing.read().contains(hash) {
+		if self.processing.read().contains_key(hash) {
 			return Status::Queued;
 		}
 		if self.verification.bad.lock().contains(hash) {
@@ -461,7 +464,7 @@ impl<K: Kind> VerificationQueue<K> {
 	pub fn import(&self, input: K::Input) -> ImportResult {
 		let h = input.hash();
 		{
-			if self.processing.read().contains(&h) {
+			if self.processing.read().contains_key(&h) {
 				return Err(ImportError::AlreadyQueued.into());
 			}
 
@@ -480,7 +483,11 @@ impl<K: Kind> VerificationQueue<K> {
 			Ok(item) => {
 				self.verification.sizes.unverified.fetch_add(item.heap_size_of_children(), AtomicOrdering::SeqCst);
 
-				self.processing.write().insert(h.clone());
+				self.processing.write().insert(h.clone(), item.difficulty());
+				{
+					let mut td = self.total_difficulty.write();
+					*td = *td + item.difficulty();
+				}
 				self.verification.unverified.lock().push_back(item);
 				self.more_to_verify.notify_all();
 				Ok(h)
@@ -511,7 +518,10 @@ impl<K: Kind> VerificationQueue<K> {
 		bad.reserve(hashes.len());
 		for hash in hashes {
 			bad.insert(hash.clone());
-			processing.remove(hash);
+			if let Some(difficulty) = processing.remove(hash) {
+				let mut td = self.total_difficulty.write();
+				*td = *td - difficulty;
+			}
 		}
 
 		let mut new_verified = VecDeque::new();
@@ -520,7 +530,10 @@ impl<K: Kind> VerificationQueue<K> {
 			if bad.contains(&output.parent_hash()) {
 				removed_size += output.heap_size_of_children();
 				bad.insert(output.hash());
-				processing.remove(&output.hash());
+				if let Some(difficulty) = processing.remove(&output.hash()) {
+					let mut td = self.total_difficulty.write();
+					*td = *td - difficulty;
+				}
 			} else {
 				new_verified.push_back(output);
 			}
@@ -538,7 +551,10 @@ impl<K: Kind> VerificationQueue<K> {
 		}
 		let mut processing = self.processing.write();
 		for hash in hashes {
-			processing.remove(hash);
+			if let Some(difficulty) = processing.remove(hash) {
+				let mut td = self.total_difficulty.write();
+				*td = *td - difficulty;
+			}
 		}
 		processing.is_empty()
 	}
@@ -592,6 +608,11 @@ impl<K: Kind> VerificationQueue<K> {
 		}
 	}
 
+	/// Get the total difficulty of all the blocks in the queue.
+	pub fn total_difficulty(&self) -> U256 {
+		self.total_difficulty.read().clone()
+	}
+
 	/// Get the current number of working verifiers.
 	pub fn num_verifiers(&self) -> usize {
 		match *self.state.0.lock() {
@@ -760,6 +781,22 @@ mod tests {
 		}
 	}
 
+	#[test]
+	fn returns_total_difficulty() {
+		let queue = get_test_queue(false);
+		let block = get_good_dummy_block();
+		let hash = BlockView::new(&block).header().hash().clone();
+		if let Err(e) = queue.import(Unverified::new(block)) {
+			panic!("error importing block that is valid by definition({:?})", e);
+		}
+		queue.flush();
+		assert_eq!(queue.total_difficulty(), 131072.into());
+		queue.drain(10);
+		assert_eq!(queue.total_difficulty(), 131072.into());
+		queue.mark_as_good(&[ hash ]);
+		assert_eq!(queue.total_difficulty(), 0.into());
+	}
+
 	#[test]
 	fn returns_ok_for_drained_duplicates() {
 		let queue = get_test_queue(false);

ethcore/src/verification/verification.rs

@@ -51,19 +51,19 @@ impl HeapSizeOf for PreverifiedBlock {
 
 /// Phase 1 quick block verification. Only does checks that are cheap. Operates on a single block
 pub fn verify_block_basic(header: &Header, bytes: &[u8], engine: &Engine) -> Result<(), Error> {
-	try!(verify_header_params(&header, engine));
+	verify_header_params(&header, engine)?;
-	try!(verify_block_integrity(bytes, &header.transactions_root(), &header.uncles_hash()));
+	verify_block_integrity(bytes, &header.transactions_root(), &header.uncles_hash())?;
-	try!(engine.verify_block_basic(&header, Some(bytes)));
+	engine.verify_block_basic(&header, Some(bytes))?;
-	for u in try!(UntrustedRlp::new(bytes).at(2)).iter().map(|rlp| rlp.as_val::<Header>()) {
+	for u in UntrustedRlp::new(bytes).at(2)?.iter().map(|rlp| rlp.as_val::<Header>()) {
-		let u = try!(u);
+		let u = u?;
-		try!(verify_header_params(&u, engine));
+		verify_header_params(&u, engine)?;
-		try!(engine.verify_block_basic(&u, None));
+		engine.verify_block_basic(&u, None)?;
 	}
 	// Verify transactions.
 	// TODO: either use transaction views or cache the decoded transactions.
 	let v = BlockView::new(bytes);
 	for t in v.transactions() {
-		try!(engine.verify_transaction_basic(&t, &header));
+		engine.verify_transaction_basic(&t, &header)?;
 	}
 	Ok(())
 }
@@ -73,9 +73,9 @@ pub fn verify_block_basic(header: &Header, bytes: &[u8], engine: &Engine) -> Res
 /// Returns a `PreverifiedBlock` structure populated with transactions
 pub fn verify_block_unordered(header: Header, bytes: Bytes, engine: &Engine, check_seal: bool) -> Result<PreverifiedBlock, Error> {
 	if check_seal {
-		try!(engine.verify_block_unordered(&header, Some(&bytes)));
+		engine.verify_block_unordered(&header, Some(&bytes))?;
-		for u in try!(UntrustedRlp::new(&bytes).at(2)).iter().map(|rlp| rlp.as_val::<Header>()) {
+		for u in UntrustedRlp::new(&bytes).at(2)?.iter().map(|rlp| rlp.as_val::<Header>()) {
-			try!(engine.verify_block_unordered(&try!(u), None));
+			engine.verify_block_unordered(&u?, None)?;
 		}
 	}
 	// Verify transactions.
@@ -83,7 +83,7 @@ pub fn verify_block_unordered(header: Header, bytes: Bytes, engine: &Engine, che
 	{
 		let v = BlockView::new(&bytes);
 		for t in v.transactions() {
-			try!(engine.verify_transaction(&t, &header));
+			engine.verify_transaction(&t, &header)?;
 			transactions.push(t);
 		}
 	}
@@ -97,11 +97,11 @@ pub fn verify_block_unordered(header: Header, bytes: Bytes, engine: &Engine, che
 /// Phase 3 verification. Check block information against parent and uncles.
 pub fn verify_block_family(header: &Header, bytes: &[u8], engine: &Engine, bc: &BlockProvider) -> Result<(), Error> {
 	// TODO: verify timestamp
-	let parent = try!(bc.block_header(&header.parent_hash()).ok_or_else(|| Error::from(BlockError::UnknownParent(header.parent_hash().clone()))));
+	let parent = bc.block_header(&header.parent_hash()).ok_or_else(|| Error::from(BlockError::UnknownParent(header.parent_hash().clone())))?;
-	try!(verify_parent(&header, &parent));
+	verify_parent(&header, &parent)?;
-	try!(engine.verify_block_family(&header, &parent, Some(bytes)));
+	engine.verify_block_family(&header, &parent, Some(bytes))?;
 
-	let num_uncles = try!(UntrustedRlp::new(bytes).at(2)).item_count();
+	let num_uncles = UntrustedRlp::new(bytes).at(2)?.item_count();
 	if num_uncles != 0 {
 		if num_uncles > engine.maximum_uncle_count() {
 			return Err(From::from(BlockError::TooManyUncles(OutOfBounds { min: None, max: Some(engine.maximum_uncle_count()), found: num_uncles })));
@@ -117,15 +117,15 @@ pub fn verify_block_family(header: &Header, bytes: &[u8], engine: &Engine, bc: &
 					excluded.insert(details.parent.clone());
 					let b = bc.block(&hash)
 						.expect("parent already known to be stored; qed");
-					excluded.extend(BlockView::new(&b).uncle_hashes());
+					excluded.extend(b.uncle_hashes());
 					hash = details.parent;
 				}
 				None => break
 			}
 		}
 
-		for uncle in try!(UntrustedRlp::new(bytes).at(2)).iter().map(|rlp| rlp.as_val::<Header>()) {
+		for uncle in UntrustedRlp::new(bytes).at(2)?.iter().map(|rlp| rlp.as_val::<Header>()) {
-			let uncle = try!(uncle);
+			let uncle = uncle?;
 			if excluded.contains(&uncle.hash()) {
 				return Err(From::from(BlockError::UncleInChain(uncle.hash())))
 			}
@@ -157,7 +157,7 @@ pub fn verify_block_family(header: &Header, bytes: &[u8], engine: &Engine, bc: &
 			// cB.p^7	-------------/
 			// cB.p^8
 			let mut expected_uncle_parent = header.parent_hash().clone();
-			let uncle_parent = try!(bc.block_header(&uncle.parent_hash()).ok_or_else(|| Error::from(BlockError::UnknownUncleParent(uncle.parent_hash().clone()))));
+			let uncle_parent = bc.block_header(&uncle.parent_hash()).ok_or_else(|| Error::from(BlockError::UnknownUncleParent(uncle.parent_hash().clone())))?;
 			for _ in 0..depth {
 				match bc.block_details(&expected_uncle_parent) {
 					Some(details) => {
@@ -170,8 +170,8 @@ pub fn verify_block_family(header: &Header, bytes: &[u8], engine: &Engine, bc: &
 				return Err(From::from(BlockError::UncleParentNotInChain(uncle_parent.hash())));
 			}
 
-			try!(verify_parent(&uncle, &uncle_parent));
+			verify_parent(&uncle, &uncle_parent)?;
-			try!(engine.verify_block_family(&uncle, &uncle_parent, Some(bytes)));
+			engine.verify_block_family(&uncle, &uncle_parent, Some(bytes))?;
 		}
 	}
 	Ok(())
@@ -234,12 +234,12 @@ fn verify_parent(header: &Header, parent: &Header) -> Result<(), Error> {
 /// Verify block data against header: transactions root and uncles hash.
 fn verify_block_integrity(block: &[u8], transactions_root: &H256, uncles_hash: &H256) -> Result<(), Error> {
 	let block = UntrustedRlp::new(block);
-	let tx = try!(block.at(1));
+	let tx = block.at(1)?;
 	let expected_root = &ordered_trie_root(tx.iter().map(|r| r.as_raw().to_vec())); //TODO: get rid of vectors here
 	if expected_root != transactions_root {
 		return Err(From::from(BlockError::InvalidTransactionsRoot(Mismatch { expected: expected_root.clone(), found: transactions_root.clone() })))
 	}
-	let expected_uncles = &try!(block.at(2)).as_raw().sha3();
+	let expected_uncles = &block.at(2)?.as_raw().sha3();
 	if expected_uncles != uncles_hash {
 		return Err(From::from(BlockError::InvalidUnclesHash(Mismatch { expected: expected_uncles.clone(), found: uncles_hash.clone() })))
 	}
@@ -264,6 +264,7 @@ mod tests {
 	use types::log_entry::{LogEntry, LocalizedLogEntry};
 	use rlp::View;
 	use time::get_time;
+	use encoded;
 
 	fn check_ok(result: Result<(), Error>) {
 		result.unwrap_or_else(|e| panic!("Block verification failed: {:?}", e));
@@ -322,16 +323,20 @@ mod tests {
 		}
 
 		/// Get raw block data
-		fn block(&self, hash: &H256) -> Option<Bytes> {
+		fn block(&self, hash: &H256) -> Option<encoded::Block> {
-			self.blocks.get(hash).cloned()
+			self.blocks.get(hash).cloned().map(encoded::Block::new)
 		}
 
-		fn block_header_data(&self, hash: &H256) -> Option<Bytes> {
+		fn block_header_data(&self, hash: &H256) -> Option<encoded::Header> {
-			self.block(hash).map(|b| BlockView::new(&b).header_rlp().as_raw().to_vec())
+			self.block(hash)
+				.map(|b| b.header_view().rlp().as_raw().to_vec())
+				.map(encoded::Header::new)
 		}
 
-		fn block_body(&self, hash: &H256) -> Option<Bytes> {
+		fn block_body(&self, hash: &H256) -> Option<encoded::Body> {
-			self.block(hash).map(|b| BlockChain::block_to_body(&b))
+			self.block(hash)
+				.map(|b| BlockChain::block_to_body(&b.into_inner()))
+				.map(encoded::Body::new)
 		}
 
 		fn best_ancient_block(&self) -> Option<H256> {

ethcore/src/views/block.rs

@@ -94,7 +94,7 @@ impl<'a> BlockView<'a> {
 	}
 
 	/// Return List of transactions in given block.
-	pub fn transaction_views(&self) -> Vec<TransactionView> {
+	pub fn transaction_views(&self) -> Vec<TransactionView<'a>> {
 		self.rlp.at(1).iter().map(TransactionView::new_from_rlp).collect()
 	}
 
@@ -132,7 +132,7 @@ impl<'a> BlockView<'a> {
 	}
 
 	/// Return List of transactions in given block.
-	pub fn uncle_views(&self) -> Vec<HeaderView> {
+	pub fn uncle_views(&self) -> Vec<HeaderView<'a>> {
 		self.rlp.at(2).iter().map(HeaderView::new_from_rlp).collect()
 	}
 

ethcore/src/views/body.rs

@@ -71,7 +71,7 @@ impl<'a> BodyView<'a> {
 	}
 
 	/// Return List of transactions in given block.
-	pub fn transaction_views(&self) -> Vec<TransactionView> {
+	pub fn transaction_views(&self) -> Vec<TransactionView<'a>> {
 		self.rlp.at(0).iter().map(TransactionView::new_from_rlp).collect()
 	}
 
@@ -106,7 +106,7 @@ impl<'a> BodyView<'a> {
 	}
 
 	/// Return List of transactions in given block.
-	pub fn uncle_views(&self) -> Vec<HeaderView> {
+	pub fn uncle_views(&self) -> Vec<HeaderView<'a>> {
 		self.rlp.at(1).iter().map(HeaderView::new_from_rlp).collect()
 	}
 

ethcrypto/src/lib.rs

@@ -158,7 +158,7 @@ pub mod aes {
 		let mut encryptor = CbcDecryptor::new(AesSafe128Decryptor::new(k), PkcsPadding, iv.to_vec());
 		let len = dest.len();
 		let mut buffer = RefWriteBuffer::new(dest);
-		try!(encryptor.decrypt(&mut RefReadBuffer::new(encrypted), &mut buffer, true));
+		encryptor.decrypt(&mut RefReadBuffer::new(encrypted), &mut buffer, true)?;
 		Ok(len - buffer.remaining())
 	}
 }
@@ -179,7 +179,7 @@ pub mod ecdh {
 			temp
 		};
 
-		let publ = try!(key::PublicKey::from_slice(context, &pdata));
+		let publ = key::PublicKey::from_slice(context, &pdata)?;
 		// no way to create SecretKey from raw byte array.
 		let sec: &key::SecretKey = unsafe { ::std::mem::transmute(secret) };
 		let shared = ecdh::SharedSecret::new_raw(context, &publ, sec);
@@ -206,7 +206,7 @@ pub mod ecies {
 		let r = Random.generate()
 			.expect("context known to have key-generation capabilities; qed");
 
-		let z = try!(ecdh::agree(r.secret(), public));
+		let z = ecdh::agree(r.secret(), public)?;
 		let mut key = [0u8; 32];
 		let mut mkey = [0u8; 32];
 		kdf(&z, &[0u8; 0], &mut key);
@@ -243,7 +243,7 @@ pub mod ecies {
 		let r = Random.generate()
 			.expect("context known to have key-generation capabilities");
 
-		let z = try!(ecdh::agree(r.secret(), public));
+		let z = ecdh::agree(r.secret(), public)?;
 		let mut key = [0u8; 32];
 		let mut mkey = [0u8; 32];
 		kdf(&z, &[0u8; 0], &mut key);
@@ -274,7 +274,7 @@ pub mod ecies {
 
 		let e = &encrypted[1..];
 		let p = Public::from_slice(&e[0..64]);
-		let z = try!(ecdh::agree(secret, &p));
+		let z = ecdh::agree(secret, &p)?;
 		let mut key = [0u8; 32];
 		kdf(&z, &[0u8; 0], &mut key);
 		let ekey = &key[0..16];
@@ -314,7 +314,7 @@ pub mod ecies {
 
 		let e = encrypted;
 		let p = Public::from_slice(&e[0..64]);
-		let z = try!(ecdh::agree(secret, &p));
+		let z = ecdh::agree(secret, &p)?;
 		let mut key = [0u8; 32];
 		kdf(&z, &[0u8; 0], &mut key);
 		let ekey = &key[0..16];

ethkey/src/bin/ethkey.rs

@@ -160,37 +160,37 @@ fn execute<S, I>(command: I) -> Result<String, Error> where I: IntoIterator<Item
 
 	return if args.cmd_info {
 		let display_mode = DisplayMode::new(&args);
-		let secret = try!(args.arg_secret.parse().map_err(|_| EthkeyError::InvalidSecret));
+		let secret = args.arg_secret.parse().map_err(|_| EthkeyError::InvalidSecret)?;
-		let keypair = try!(KeyPair::from_secret(secret));
+		let keypair = KeyPair::from_secret(secret)?;
 		Ok(display(keypair, display_mode))
 	} else if args.cmd_generate {
 		let display_mode = DisplayMode::new(&args);
 		let keypair = if args.cmd_random {
 			Random.generate()
 		} else if args.cmd_prefix {
-			let prefix = try!(args.arg_prefix.from_hex());
+			let prefix = args.arg_prefix.from_hex()?;
-			let iterations = try!(usize::from_str_radix(&args.arg_iterations, 10));
+			let iterations = usize::from_str_radix(&args.arg_iterations, 10)?;
 			Prefix::new(prefix, iterations).generate()
 		} else if args.cmd_brain {
 			Brain::new(args.arg_seed).generate()
 		} else {
 			unreachable!();
 		};
-		Ok(display(try!(keypair), display_mode))
+		Ok(display(keypair?, display_mode))
 	} else if args.cmd_sign {
-		let secret = try!(args.arg_secret.parse().map_err(|_| EthkeyError::InvalidSecret));
+		let secret = args.arg_secret.parse().map_err(|_| EthkeyError::InvalidSecret)?;
-		let message = try!(args.arg_message.parse().map_err(|_| EthkeyError::InvalidMessage));
+		let message = args.arg_message.parse().map_err(|_| EthkeyError::InvalidMessage)?;
-		let signature = try!(sign(&secret, &message));
+		let signature = sign(&secret, &message)?;
 		Ok(format!("{}", signature))
 	} else if args.cmd_verify {
-		let signature = try!(args.arg_signature.parse().map_err(|_| EthkeyError::InvalidSignature));
+		let signature = args.arg_signature.parse().map_err(|_| EthkeyError::InvalidSignature)?;
-		let message = try!(args.arg_message.parse().map_err(|_| EthkeyError::InvalidMessage));
+		let message = args.arg_message.parse().map_err(|_| EthkeyError::InvalidMessage)?;
 		let ok = if args.cmd_public {
-			let public = try!(args.arg_public.parse().map_err(|_| EthkeyError::InvalidPublic));
+			let public = args.arg_public.parse().map_err(|_| EthkeyError::InvalidPublic)?;
-			try!(verify_public(&public, &signature, &message))
+			verify_public(&public, &signature, &message)?
 		} else if args.cmd_address {
-			let address = try!(args.arg_address.parse().map_err(|_| EthkeyError::InvalidAddress));
+			let address = args.arg_address.parse().map_err(|_| EthkeyError::InvalidAddress)?;
-			try!(verify_address(&address, &signature, &message))
+			verify_address(&address, &signature, &message)?
 		} else {
 			unreachable!();
 		};

ethkey/src/keypair.rs

@@ -35,8 +35,8 @@ pub struct KeyPair {
 
 impl fmt::Display for KeyPair {
 	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-		try!(writeln!(f, "secret:  {}", self.secret.to_hex()));
+		writeln!(f, "secret:  {}", self.secret.to_hex())?;
-		try!(writeln!(f, "public:  {}", self.public.to_hex()));
+		writeln!(f, "public:  {}", self.public.to_hex())?;
 		write!(f, "address: {}", self.address().to_hex())
 	}
 }
@@ -45,8 +45,8 @@ impl KeyPair {
 	/// Create a pair from secret key
 	pub fn from_secret(secret: Secret) -> Result<KeyPair, Error> {
 		let context = &SECP256K1;
-		let s: key::SecretKey = try!(key::SecretKey::from_slice(context, &secret[..]));
+		let s: key::SecretKey = key::SecretKey::from_slice(context, &secret[..])?;
-		let pub_key = try!(key::PublicKey::from_secret_key(context, &s));
+		let pub_key = key::PublicKey::from_secret_key(context, &s)?;
 		let serialized = pub_key.serialize_vec(context, false);
 
 		let mut public = Public::default();

ethkey/src/prefix.rs

@@ -34,7 +34,7 @@ impl Prefix {
 impl Generator for Prefix {
 	fn generate(self) -> Result<KeyPair, Error> {
 		for _ in 0..self.iterations {
-			let keypair = try!(Random.generate());
+			let keypair = Random.generate()?;
 			if keypair.address().starts_with(&self.prefix) {
 				return Ok(keypair)
 			}

ethkey/src/random.rs

@@ -23,8 +23,8 @@ pub struct Random;
 impl Generator for Random {
 	fn generate(self) -> Result<KeyPair, Error> {
 		let context = &SECP256K1;
-		let mut rng = try!(OsRng::new());
+		let mut rng = OsRng::new()?;
-		let (sec, publ) = try!(context.generate_keypair(&mut rng));
+		let (sec, publ) = context.generate_keypair(&mut rng)?;
 
 		Ok(KeyPair::from_keypair(sec, publ))
 	}

ethkey/src/signature.rs

@@ -171,7 +171,7 @@ pub fn sign(secret: &Secret, message: &Message) -> Result<Signature, Error> {
 	let context = &SECP256K1;
 	// no way to create from raw byte array.
 	let sec: &SecretKey = unsafe { mem::transmute(secret) };
-	let s = try!(context.sign_recoverable(&try!(SecpMessage::from_slice(&message[..])), sec));
+	let s = context.sign_recoverable(&SecpMessage::from_slice(&message[..])?, sec)?;
 	let (rec_id, data) = s.serialize_compact(context);
 	let mut data_arr = [0; 65];
 
@@ -183,7 +183,7 @@ pub fn sign(secret: &Secret, message: &Message) -> Result<Signature, Error> {
 
 pub fn verify_public(public: &Public, signature: &Signature, message: &Message) -> Result<bool, Error> {
 	let context = &SECP256K1;
-	let rsig = try!(RecoverableSignature::from_compact(context, &signature[0..64], try!(RecoveryId::from_i32(signature[64] as i32))));
+	let rsig = RecoverableSignature::from_compact(context, &signature[0..64], RecoveryId::from_i32(signature[64] as i32)?)?;
 	let sig = rsig.to_standard(context);
 
 	let pdata: [u8; 65] = {
@@ -192,8 +192,8 @@ pub fn verify_public(public: &Public, signature: &Signature, message: &Message)
 		temp
 	};
 
-	let publ = try!(PublicKey::from_slice(context, &pdata));
+	let publ = PublicKey::from_slice(context, &pdata)?;
-	match context.verify(&try!(SecpMessage::from_slice(&message[..])), &sig, &publ) {
+	match context.verify(&SecpMessage::from_slice(&message[..])?, &sig, &publ) {
 		Ok(_) => Ok(true),
 		Err(SecpError::IncorrectSignature) => Ok(false),
 		Err(x) => Err(Error::from(x))
@@ -201,15 +201,15 @@ pub fn verify_public(public: &Public, signature: &Signature, message: &Message)
 }
 
 pub fn verify_address(address: &Address, signature: &Signature, message: &Message) -> Result<bool, Error> {
-	let public = try!(recover(signature, message));
+	let public = recover(signature, message)?;
 	let recovered_address = public_to_address(&public);
 	Ok(address == &recovered_address)
 }
 
 pub fn recover(signature: &Signature, message: &Message) -> Result<Public, Error> {
 	let context = &SECP256K1;
-	let rsig = try!(RecoverableSignature::from_compact(context, &signature[0..64], try!(RecoveryId::from_i32(signature[64] as i32))));
+	let rsig = RecoverableSignature::from_compact(context, &signature[0..64], RecoveryId::from_i32(signature[64] as i32)?)?;
-	let pubkey = try!(context.recover(&try!(SecpMessage::from_slice(&message[..])), &rsig));
+	let pubkey = context.recover(&SecpMessage::from_slice(&message[..])?, &rsig)?;
 	let serialized = pubkey.serialize_vec(context, false);
 
 	let mut public = Public::default();

ethstore/src/account/safe_account.rs

@@ -113,7 +113,7 @@ impl Crypto {
 
 		let (derived_left_bits, derived_right_bits) = match self.kdf {
 			Kdf::Pbkdf2(ref params) => crypto::derive_key_iterations(password, &params.salt, params.c),
-			Kdf::Scrypt(ref params) => try!(crypto::derive_key_scrypt(password, &params.salt, params.n, params.p, params.r)),
+			Kdf::Scrypt(ref params) => crypto::derive_key_scrypt(password, &params.salt, params.n, params.p, params.r)?,
 		};
 
 		let mac = crypto::derive_mac(&derived_right_bits, &self.ciphertext).keccak256();
@@ -171,22 +171,22 @@ impl SafeAccount {
 	}
 
 	pub fn sign(&self, password: &str, message: &Message) -> Result<Signature, Error> {
-		let secret = try!(self.crypto.secret(password));
+		let secret = self.crypto.secret(password)?;
 		sign(&secret, message).map_err(From::from)
 	}
 
 	pub fn decrypt(&self, password: &str, shared_mac: &[u8], message: &[u8]) -> Result<Vec<u8>, Error> {
-		let secret = try!(self.crypto.secret(password));
+		let secret = self.crypto.secret(password)?;
 		crypto::ecies::decrypt(&secret, shared_mac, message).map_err(From::from)
 	}
 
 	pub fn public(&self, password: &str) -> Result<Public, Error> {
-		let secret = try!(self.crypto.secret(password));
+		let secret = self.crypto.secret(password)?;
-		Ok(try!(KeyPair::from_secret(secret)).public().clone())
+		Ok(KeyPair::from_secret(secret)?.public().clone())
 	}
 
 	pub fn change_password(&self, old_password: &str, new_password: &str, iterations: u32) -> Result<Self, Error> {
-		let secret = try!(self.crypto.secret(old_password));
+		let secret = self.crypto.secret(old_password)?;
 		let result = SafeAccount {
 			id: self.id.clone(),
 			version: self.version.clone(),

ethstore/src/bin/ethstore.rs

@@ -93,11 +93,11 @@ fn main() {
 
 fn key_dir(location: &str) -> Result<Box<KeyDirectory>, Error> {
 	let dir: Box<KeyDirectory> = match location {
-		"parity" => Box::new(try!(ParityDirectory::create(DirectoryType::Main))),
+		"parity" => Box::new(ParityDirectory::create(DirectoryType::Main)?),
-		"parity-test" => Box::new(try!(ParityDirectory::create(DirectoryType::Testnet))),
+		"parity-test" => Box::new(ParityDirectory::create(DirectoryType::Testnet)?),
-		"geth" => Box::new(try!(GethDirectory::create(DirectoryType::Main))),
+		"geth" => Box::new(GethDirectory::create(DirectoryType::Main)?),
-		"geth-test" => Box::new(try!(GethDirectory::create(DirectoryType::Testnet))),
+		"geth-test" => Box::new(GethDirectory::create(DirectoryType::Testnet)?),
-		path => Box::new(try!(DiskDirectory::create(path))),
+		path => Box::new(DiskDirectory::create(path)?),
 	};
 
 	Ok(dir)
@@ -112,9 +112,9 @@ fn format_accounts(accounts: &[Address]) -> String {
 }
 
 fn load_password(path: &str) -> Result<String, Error> {
-	let mut file = try!(fs::File::open(path));
+	let mut file = fs::File::open(path)?;
 	let mut password = String::new();
-	try!(file.read_to_string(&mut password));
+	file.read_to_string(&mut password)?;
 	// drop EOF
 	let _ = password.pop();
 	Ok(password)
@@ -125,48 +125,48 @@ fn execute<S, I>(command: I) -> Result<String, Error> where I: IntoIterator<Item
 		.and_then(|d| d.argv(command).decode())
 		.unwrap_or_else(|e| e.exit());
 
-	let store = try!(EthStore::open(try!(key_dir(&args.flag_dir))));
+	let store = EthStore::open(key_dir(&args.flag_dir)?)?;
 
 	return if args.cmd_insert {
-		let secret = try!(args.arg_secret.parse().map_err(|_| Error::InvalidSecret));
+		let secret = args.arg_secret.parse().map_err(|_| Error::InvalidSecret)?;
-		let password = try!(load_password(&args.arg_password));
+		let password = load_password(&args.arg_password)?;
-		let address = try!(store.insert_account(secret, &password));
+		let address = store.insert_account(secret, &password)?;
 		Ok(format!("0x{:?}", address))
 	} else if args.cmd_change_pwd {
-		let address = try!(args.arg_address.parse().map_err(|_| Error::InvalidAccount));
+		let address = args.arg_address.parse().map_err(|_| Error::InvalidAccount)?;
-		let old_pwd = try!(load_password(&args.arg_old_pwd));
+		let old_pwd = load_password(&args.arg_old_pwd)?;
-		let new_pwd = try!(load_password(&args.arg_new_pwd));
+		let new_pwd = load_password(&args.arg_new_pwd)?;
 		let ok = store.change_password(&address, &old_pwd, &new_pwd).is_ok();
 		Ok(format!("{}", ok))
 	} else if args.cmd_list {
-		let accounts = try!(store.accounts());
+		let accounts = store.accounts()?;
 		Ok(format_accounts(&accounts))
 	} else if args.cmd_import {
-		let src = try!(key_dir(&args.flag_src));
+		let src = key_dir(&args.flag_src)?;
-		let dst = try!(key_dir(&args.flag_dir));
+		let dst = key_dir(&args.flag_dir)?;
-		let accounts = try!(import_accounts(&*src, &*dst));
+		let accounts = import_accounts(&*src, &*dst)?;
 		Ok(format_accounts(&accounts))
 	} else if args.cmd_import_wallet {
-		let wallet = try!(PresaleWallet::open(&args.arg_path));
+		let wallet = PresaleWallet::open(&args.arg_path)?;
-		let password = try!(load_password(&args.arg_password));
+		let password = load_password(&args.arg_password)?;
-		let kp = try!(wallet.decrypt(&password));
+		let kp = wallet.decrypt(&password)?;
-		let address = try!(store.insert_account(kp.secret().clone(), &password));
+		let address = store.insert_account(kp.secret().clone(), &password)?;
 		Ok(format!("0x{:?}", address))
 	} else if args.cmd_remove {
-		let address = try!(args.arg_address.parse().map_err(|_| Error::InvalidAccount));
+		let address = args.arg_address.parse().map_err(|_| Error::InvalidAccount)?;
-		let password = try!(load_password(&args.arg_password));
+		let password = load_password(&args.arg_password)?;
 		let ok = store.remove_account(&address, &password).is_ok();
 		Ok(format!("{}", ok))
 	} else if args.cmd_sign {
-		let address = try!(args.arg_address.parse().map_err(|_| Error::InvalidAccount));
+		let address = args.arg_address.parse().map_err(|_| Error::InvalidAccount)?;
-		let message = try!(args.arg_message.parse().map_err(|_| Error::InvalidMessage));
+		let message = args.arg_message.parse().map_err(|_| Error::InvalidMessage)?;
-		let password = try!(load_password(&args.arg_password));
+		let password = load_password(&args.arg_password)?;
-		let signature = try!(store.sign(&address, &password, &message));
+		let signature = store.sign(&address, &password, &message)?;
 		Ok(format!("0x{:?}", signature))
 	} else if args.cmd_public {
-		let address = try!(args.arg_address.parse().map_err(|_| Error::InvalidAccount));
+		let address = args.arg_address.parse().map_err(|_| Error::InvalidAccount)?;
-		let password = try!(load_password(&args.arg_password));
+		let password = load_password(&args.arg_password)?;
-		let public = try!(store.public(&address, &password));
+		let public = store.public(&address, &password)?;
 		Ok(format!("0x{:?}", public))
 	} else {
 		Ok(format!("{}", USAGE))

ethstore/src/dir/disk.rs

@@ -29,8 +29,8 @@ fn restrict_permissions_to_owner(file_path: &Path) -> Result<(), i32>  {
 	use std::ffi;
 	use libc;
 
-	let cstr = try!(ffi::CString::new(&*file_path.to_string_lossy())
+	let cstr = ffi::CString::new(&*file_path.to_string_lossy())
-		.map_err(|_| -1));
+		.map_err(|_| -1)?;
 	match unsafe { libc::chmod(cstr.as_ptr(), libc::S_IWUSR | libc::S_IRUSR) } {
 		0 => Ok(()),
 		x => Err(x),
@@ -48,7 +48,7 @@ pub struct DiskDirectory {
 
 impl DiskDirectory {
 	pub fn create<P>(path: P) -> Result<Self, Error> where P: AsRef<Path> {
-		try!(fs::create_dir_all(&path));
+		fs::create_dir_all(&path)?;
 		Ok(Self::at(path))
 	}
 
@@ -62,7 +62,7 @@ impl DiskDirectory {
 	fn files(&self) -> Result<HashMap<PathBuf, SafeAccount>, Error> {
 		// it's not done using one iterator cause
 		// there is an issue with rustc and it takes tooo much time to compile
-		let paths = try!(fs::read_dir(&self.path))
+		let paths = fs::read_dir(&self.path)?
 			.flat_map(Result::ok)
 			.filter(|entry| {
 				let metadata = entry.metadata().ok();
@@ -102,7 +102,7 @@ impl DiskDirectory {
 
 impl KeyDirectory for DiskDirectory {
 	fn load(&self) -> Result<Vec<SafeAccount>, Error> {
-		let accounts = try!(self.files())
+		let accounts = self.files()?
 			.into_iter()
 			.map(|(_, account)| account)
 			.collect();
@@ -134,8 +134,8 @@ impl KeyDirectory for DiskDirectory {
 			keyfile_path.push(filename.as_str());
 
 			// save the file
-			let mut file = try!(fs::File::create(&keyfile_path));
+			let mut file = fs::File::create(&keyfile_path)?;
-			try!(keyfile.write(&mut file).map_err(|e| Error::Custom(format!("{:?}", e))));
+			keyfile.write(&mut file).map_err(|e| Error::Custom(format!("{:?}", e)))?;
 
 			if let Err(_) = restrict_permissions_to_owner(keyfile_path.as_path()) {
 				fs::remove_file(keyfile_path).expect("Expected to remove recently created file");
@@ -149,7 +149,7 @@ impl KeyDirectory for DiskDirectory {
 	fn remove(&self, account: &SafeAccount) -> Result<(), Error> {
 		// enumerate all entries in keystore
 		// and find entry with given address
-		let to_remove = try!(self.files())
+		let to_remove = self.files()?
 			.into_iter()
 			.find(|&(_, ref acc)| acc == account);