sweep most unwraps from ethcore crate, dapps crate (#2762)

* sweep most unwraps from ethcore crate

* purge unwrap from dapps server

* whitespace

[ci:none]

Cargo.lock

@@ -335,6 +335,7 @@ dependencies = [
  "jsonrpc-http-server 6.1.1 (git+https://github.com/ethcore/jsonrpc-http-server.git)",
  "linked-hash-map 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mime 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "mime_guess 1.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-dapps 1.4.0 (git+https://github.com/ethcore/parity-ui.git)",
  "parity-dapps-glue 1.4.0",

dapps/Cargo.toml

@@ -29,6 +29,7 @@ ethcore-util = { path = "../util" }
 fetch = { path = "../util/fetch" }
 parity-ui = { path = "./ui" }
 parity-dapps-glue = { path = "./js-glue" }
+mime = "0.2"
 ### DEPRECATED
 parity-dapps = { git = "https://github.com/ethcore/parity-ui.git", version = "1.4" }
 parity-dapps-home = { git = "https://github.com/ethcore/parity-ui.git", version = "1.4" }

dapps/js-glue/src/lib.rs.in

@@ -27,6 +27,7 @@ use std::default::Default;
 pub struct File {
 	pub path: &'static str,
 	pub content: &'static [u8],
+	// TODO: use strongly-typed MIME.
 	pub content_type: &'static str,
 }
 

dapps/src/api/response.rs

@@ -19,12 +19,16 @@ use serde_json;
 use endpoint::Handler;
 use handlers::{ContentHandler, EchoHandler};
 
-pub fn as_json<T : Serialize>(val: &T) -> Box<Handler> {
-	Box::new(ContentHandler::ok(serde_json::to_string(val).unwrap(), "application/json".to_owned()))
+pub fn as_json<T: Serialize>(val: &T) -> Box<Handler> {
+	let json = serde_json::to_string(val)
+		.expect("serialization to string is infallible; qed");
+	Box::new(ContentHandler::ok(json, mime!(Application/Json)))
 }
 
-pub fn as_json_error<T : Serialize>(val: &T) -> Box<Handler> {
-	Box::new(ContentHandler::not_found(serde_json::to_string(val).unwrap(), "application/json".to_owned()))
+pub fn as_json_error<T: Serialize>(val: &T) -> Box<Handler> {
+	let json = serde_json::to_string(val)
+		.expect("serialization to string is infallible; qed");
+	Box::new(ContentHandler::not_found(json, mime!(Application/Json)))
 }
 
 pub fn ping_response(local_domain: &str) -> Box<Handler> {

dapps/src/apps/cache.rs

@@ -54,8 +54,10 @@ impl ContentCache {
 		}
 
 		let mut removed = Vec::with_capacity(len - expected_size);
-		while len > expected_size {
-			let entry = self.cache.pop_front().unwrap();
+
+		while self.cache.len() > expected_size {
+			let entry = self.cache.pop_front().expect("expected_size bounded at 0, len is greater; qed");
+
 			match entry.1 {
 				ContentStatus::Fetching(ref fetch) => {
 					trace!(target: "dapps", "Aborting {} because of limit.", entry.0);
@@ -73,7 +75,6 @@ impl ContentCache {
 			}
 
 			removed.push(entry);
-			len -= 1;
 		}
 		removed
 	}

dapps/src/apps/urlhint.rs

@@ -156,9 +156,9 @@ impl URLHintContract {
 			}
 
 			let mut it = vec.into_iter();
-			let account_slash_repo = it.next().unwrap();
-			let commit = it.next().unwrap();
-			let owner = it.next().unwrap();
+			let account_slash_repo = it.next().expect("element 0 of 3-len vector known to exist; qed");
+			let commit = it.next().expect("element 1 of 3-len vector known to exist; qed");
+			let owner = it.next().expect("element 2 of 3-len vector known to exist qed");
 
 			match (account_slash_repo, commit, owner) {
 				(Token::String(account_slash_repo), Token::FixedBytes(commit), Token::Address(owner)) => {

dapps/src/handlers/content.rs

@@ -19,6 +19,7 @@
 use std::io::Write;
 use hyper::{header, server, Decoder, Encoder, Next};
 use hyper::net::HttpStream;
+use hyper::mime::Mime;
 use hyper::status::StatusCode;
 
 use util::version;
@@ -29,22 +30,22 @@ use handlers::add_security_headers;
 pub struct ContentHandler {
 	code: StatusCode,
 	content: String,
-	mimetype: String,
+	mimetype: Mime,
 	write_pos: usize,
 	safe_to_embed_at_port: Option<u16>,
 }
 
 impl ContentHandler {
-	pub fn ok(content: String, mimetype: String) -> Self {
+	pub fn ok(content: String, mimetype: Mime) -> Self {
 		Self::new(StatusCode::Ok, content, mimetype)
 	}
 
-	pub fn not_found(content: String, mimetype: String) -> Self {
+	pub fn not_found(content: String, mimetype: Mime) -> Self {
 		Self::new(StatusCode::NotFound, content, mimetype)
 	}
 
 	pub fn html(code: StatusCode, content: String, embeddable_at: Option<u16>) -> Self {
-		Self::new_embeddable(code, content, "text/html".into(), embeddable_at)
+		Self::new_embeddable(code, content, mime!(Text/Html), embeddable_at)
 	}
 
 	pub fn error(code: StatusCode, title: &str, message: &str, details: Option<&str>) -> Self {
@@ -61,11 +62,11 @@ impl ContentHandler {
 		), embeddable_at)
 	}
 
-	pub fn new(code: StatusCode, content: String, mimetype: String) -> Self {
+	pub fn new(code: StatusCode, content: String, mimetype: Mime) -> Self {
 		Self::new_embeddable(code, content, mimetype, None)
 	}
 
-	pub fn new_embeddable(code: StatusCode, content: String, mimetype: String, embeddable_at: Option<u16>) -> Self {
+	pub fn new_embeddable(code: StatusCode, content: String, mimetype: Mime, embeddable_at: Option<u16>) -> Self {
 		ContentHandler {
 			code: code,
 			content: content,
@@ -87,7 +88,7 @@ impl server::Handler<HttpStream> for ContentHandler {
 
 	fn on_response(&mut self, res: &mut server::Response) -> Next {
 		res.set_status(self.code);
-		res.headers_mut().set(header::ContentType(self.mimetype.parse().unwrap()));
+		res.headers_mut().set(header::ContentType(self.mimetype.clone()));
 		add_security_headers(&mut res.headers_mut(), self.safe_to_embed_at_port.clone());
 		Next::write()
 	}

dapps/src/handlers/echo.rs

@@ -82,7 +82,7 @@ impl server::Handler<HttpStream> for EchoHandler {
 
 		// Don't even read the payload if origin is forbidden!
 		if let Cors::Forbidden = self.cors {
-			self.handler = Some(ContentHandler::ok(String::new(), "text/plain".into()));
+			self.handler = Some(ContentHandler::ok(String::new(), mime!(Text/Plain)));
 			Next::write()
 		} else {
 			Next::read()
@@ -92,7 +92,7 @@ impl server::Handler<HttpStream> for EchoHandler {
 	fn on_request_readable(&mut self, decoder: &mut Decoder<HttpStream>) -> Next {
 		match decoder.read_to_string(&mut self.content) {
 			Ok(0) => {
-				self.handler = Some(ContentHandler::ok(self.content.clone(), "application/json".into()));
+				self.handler = Some(ContentHandler::ok(self.content.clone(), mime!(Application/Json)));
 				Next::write()
 			},
 			Ok(_) => Next::read(),
@@ -114,11 +114,15 @@ impl server::Handler<HttpStream> for EchoHandler {
 			]));
 			headers.set(header::AccessControlAllowOrigin::Value(domain.clone()));
 		}
-		self.handler.as_mut().unwrap().on_response(res)
+		self.handler.as_mut()
+			.expect("handler always set in on_request, which is before now; qed")
+			.on_response(res)
 	}
 
 	fn on_response_writable(&mut self, encoder: &mut Encoder<HttpStream>) -> Next {
-		self.handler.as_mut().unwrap().on_response_writable(encoder)
+		self.handler.as_mut()
+			.expect("handler always set in on_request, which is before now; qed")
+			.on_response_writable(encoder)
 	}
 }
 

dapps/src/lib.rs

@@ -43,10 +43,8 @@
 #![warn(missing_docs)]
 #![cfg_attr(feature="nightly", plugin(clippy))]
 
-#[macro_use]
-extern crate log;
-extern crate url as url_lib;
 extern crate hyper;
+extern crate url as url_lib;
 extern crate unicase;
 extern crate serde;
 extern crate serde_json;
@@ -61,6 +59,13 @@ extern crate ethcore_rpc;
 extern crate ethcore_util as util;
 extern crate linked_hash_map;
 extern crate fetch;
+
+#[macro_use]
+extern crate log;
+
+#[macro_use]
+extern crate mime;
+
 #[cfg(test)]
 extern crate ethcore_devtools as devtools;
 

dapps/src/page/handler.rs

@@ -128,7 +128,12 @@ impl<T: Dapp> server::Handler<HttpStream> for PageHandler<T> {
 		match self.file {
 			ServedFile::File(ref f) => {
 				res.set_status(StatusCode::Ok);
-				res.headers_mut().set(header::ContentType(f.content_type().parse().unwrap()));
+
+				match f.content_type().parse() {
+					Ok(mime) => res.headers_mut().set(header::ContentType(mime)),
+					Err(()) => debug!(target: "page_handler", "invalid MIME type: {}", f.content_type()),
+				}
+
 				// Security headers:
 				add_security_headers(&mut res.headers_mut(), self.safe_to_embed_at_port);
 				Next::write()

dapps/src/proxypac.rs

@@ -42,7 +42,7 @@ function FindProxyForURL(url, host) {{
 }}
 "#,
 			DAPPS_DOMAIN, path.host, path.port);
-		Box::new(ContentHandler::ok(content, "application/javascript".to_owned()))
+		Box::new(ContentHandler::ok(content, mime!(Application/Javascript)))
 	}
 }
 

dapps/src/router/mod.rs

@@ -81,11 +81,15 @@ impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 		self.handler = match endpoint {
 			// First check special endpoints
 			(ref path, ref endpoint) if self.special.contains_key(endpoint) => {
-				self.special.get(endpoint).unwrap().to_async_handler(path.clone().unwrap_or_default(), control)
+				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) => {
-				self.endpoints.get(&path.app_id).unwrap().to_async_handler(path.clone(), control)
+				self.endpoints.get(&path.app_id)
+					.expect("special 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) => {
@@ -108,7 +112,9 @@ impl<A: Authorization + 'static> server::Handler<HttpStream> for Router<A> {
 			},
 			// RPC by default
 			_ => {
-				self.special.get(&SpecialEndpoint::Rpc).unwrap().to_async_handler(EndpointPath::default(), control)
+				self.special.get(&SpecialEndpoint::Rpc)
+					.expect("RPC endpoint always stored; qed")
+					.to_async_handler(EndpointPath::default(), control)
 			}
 		};
 
@@ -143,7 +149,9 @@ impl<A: Authorization> Router<A> {
 		allowed_hosts: Option<Vec<String>>,
 		) -> Self {
 
-		let handler = special.get(&SpecialEndpoint::Utils).unwrap().to_handler(EndpointPath::default());
+		let handler = special.get(&SpecialEndpoint::Utils)
+			.expect("Utils endpoint always stored; qed")
+			.to_handler(EndpointPath::default());
 		Router {
 			control: Some(control),
 			main_page: main_page,

ethcore/src/account_provider.rs

@@ -176,7 +176,8 @@ impl AccountProvider {
 		AccountProvider {
 			unlocked: Mutex::new(HashMap::new()),
 			address_book: Mutex::new(AddressBook::new(Default::default())),
-			sstore: Box::new(EthStore::open(Box::new(NullDir::default())).unwrap())
+			sstore: Box::new(EthStore::open(Box::new(NullDir::default()))
+				.expect("NullDir load always succeeds; qed"))
 		}
 	}
 
@@ -187,7 +188,7 @@ impl AccountProvider {
 
 	/// Creates new random account and returns address and public key
 	pub fn new_account_and_public(&self, password: &str) -> Result<(Address, Public), Error> {
-		let acc = Random.generate().unwrap();
+		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));

ethcore/src/block.rs

@@ -350,7 +350,7 @@ impl<'x> OpenBlock<'x> {
 				let t = outcome.trace;
 				self.block.traces.as_mut().map(|traces| traces.push(t));
 				self.block.receipts.push(outcome.receipt);
-				Ok(self.block.receipts.last().unwrap())
+				Ok(self.block.receipts.last().expect("receipt just pushed; qed"))
 			}
 			Err(x) => Err(From::from(x))
 		}

ethcore/src/blockchain/blockchain.rs

@@ -132,7 +132,8 @@ pub trait BlockProvider {
 
 	/// Returns the header of the genesis block.
 	fn genesis_header(&self) -> Header {
-		self.block_header(&self.genesis_hash()).unwrap()
+		self.block_header(&self.genesis_hash())
+			.expect("Genesis header always stored; qed")
 	}
 
 	/// Returns numbers of blocks containing given bloom.

ethcore/src/cache_manager.rs

@@ -55,18 +55,23 @@ impl<T> CacheManager<T> where T: Eq + Hash {
 		}
 
 		for _ in 0..COLLECTION_QUEUE_SIZE {
-			let current_size = notify_unused(self.cache_usage.pop_back().unwrap());
-			self.cache_usage.push_front(Default::default());
-			if current_size < self.max_cache_size {
-				break;
+			if let Some(back) = self.cache_usage.pop_back() {
+				let current_size = notify_unused(back);
+				self.cache_usage.push_front(Default::default());
+				if current_size < self.max_cache_size {
+					break
+				}
 			}
 		}
 	}
 
 	fn rotate_cache_if_needed(&mut self) {
+		if self.cache_usage.len() == 0 { return }
+
 		if self.cache_usage[0].len() * self.bytes_per_cache_entry > self.pref_cache_size / COLLECTION_QUEUE_SIZE {
-			let cache = self.cache_usage.pop_back().unwrap();
-			self.cache_usage.push_front(cache);
+			if let Some(cache) = self.cache_usage.pop_back() {
+				self.cache_usage.push_front(cache);
+			}
 		}
 	}
 }

ethcore/src/client/client.rs

@@ -478,7 +478,11 @@ impl Client {
 
 		if number >= self.history {
 			let n = number - self.history;
-			state.mark_canonical(&mut batch, n, &chain.block_hash(n).unwrap()).expect("DB commit failed");
+			if let Some(ancient_hash) = chain.block_hash(n) {
+				state.mark_canonical(&mut batch, n, &ancient_hash).expect("DB commit failed");
+			} else {
+				debug!(target: "client", "Missing expected hash for block {}", n);
+			}
 		}
 
 		let route = chain.insert_block(&mut batch, block_data, receipts);

ethcore/src/engines/mod.rs

@@ -123,10 +123,14 @@ pub trait Engine : Sync + Send {
 	fn is_builtin(&self, a: &Address) -> bool { self.builtins().contains_key(a) }
 	/// Determine the code execution cost of the builtin contract with address `a`.
 	/// Panics if `is_builtin(a)` is not true.
-	fn cost_of_builtin(&self, a: &Address, input: &[u8]) -> U256 { self.builtins().get(a).unwrap().cost(input.len()) }
+	fn cost_of_builtin(&self, a: &Address, input: &[u8]) -> U256 {
+		self.builtins().get(a).expect("queried cost of nonexistent builtin").cost(input.len())
+	}
 	/// Execution the builtin contract `a` on `input` and return `output`.
 	/// Panics if `is_builtin(a)` is not true.
-	fn execute_builtin(&self, a: &Address, input: &[u8], output: &mut BytesRef) { self.builtins().get(a).unwrap().execute(input, output); }
+	fn execute_builtin(&self, a: &Address, input: &[u8], output: &mut BytesRef) {
+		self.builtins().get(a).expect("attempted to execute nonexistent builtin").execute(input, output);
+	}
 
 	// TODO: sealing stuff - though might want to leave this for later.
 }

ethcore/src/evm/interpreter/mod.rs

@@ -102,7 +102,7 @@ impl<Cost: CostType> evm::Evm for Interpreter<Cost> {
 
 		let mut informant = informant::EvmInformant::new(ext.depth());
 
-		let code = &params.code.as_ref().unwrap();
+		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)));
@@ -318,11 +318,11 @@ impl<Cost: CostType> Interpreter<Cost> {
 				// Get sender & receive addresses, check if we have balance
 				let (sender_address, receive_address, has_balance, call_type) = match instruction {
 					instructions::CALL => {
-						let has_balance = ext.balance(&params.address) >= value.unwrap();
+						let has_balance = ext.balance(&params.address) >= value.expect("value set for all but delegate call; qed");
 						(&params.address, &code_address, has_balance, CallType::Call)
 					},
 					instructions::CALLCODE => {
-						let has_balance = ext.balance(&params.address) >= value.unwrap();
+						let has_balance = ext.balance(&params.address) >= value.expect("value set for all but delegate call; qed");
 						(&params.address, &params.address, has_balance, CallType::CallCode)
 					},
 					instructions::DELEGATECALL => (&params.sender, &params.address, true, CallType::DelegateCall),

ethcore/src/evm/jit.rs

@@ -359,7 +359,7 @@ impl evm::Evm for JitEvm {
 		data.timestamp = ext.env_info().timestamp as i64;
 
 		self.context = Some(unsafe { evmjit::ContextHandle::new(data, schedule, &mut ext_handle) });
-		let mut context = self.context.as_mut().unwrap();
+		let mut context = self.context.as_mut().expect("context handle set on the prior line; qed");
 		let res = context.exec();
 
 		match res {

ethcore/src/executive.rs

@@ -427,8 +427,16 @@ impl<'a> Executive<'a> {
 		trace!("exec::finalize: t.gas={}, sstore_refunds={}, suicide_refunds={}, refunds_bound={}, gas_left_prerefund={}, refunded={}, gas_left={}, gas_used={}, refund_value={}, fees_value={}\n",
 			t.gas, sstore_refunds, suicide_refunds, refunds_bound, gas_left_prerefund, refunded, gas_left, gas_used, refund_value, fees_value);
 
-		trace!("exec::finalize: Refunding refund_value={}, sender={}\n", refund_value, t.sender().unwrap());
-		self.state.add_balance(&t.sender().unwrap(), &refund_value);
+		let sender = match t.sender() {
+			Ok(sender) => sender,
+			Err(e) => {
+				debug!(target: "executive", "attempted to finalize transaction without sender: {}", e);
+				return Err(ExecutionError::Internal);
+			}
+		};
+
+		trace!("exec::finalize: Refunding refund_value={}, sender={}\n", refund_value, sender);
+		self.state.add_balance(&sender, &refund_value);
 		trace!("exec::finalize: Compensating author: fees_value={}, author={}\n", fees_value, &self.info.author);
 		self.state.add_balance(&self.info.author, &fees_value);
 

ethcore/src/header.rs

@@ -199,8 +199,9 @@ impl Header {
  		match &mut *hash {
  			&mut Some(ref h) => h.clone(),
  			hash @ &mut None => {
- 				*hash = Some(self.rlp_sha3(Seal::With));
- 				hash.as_ref().unwrap().clone()
+				let h = self.rlp_sha3(Seal::With);
+ 				*hash = Some(h.clone());
+ 				h
  			}
 		}
 	}
@@ -211,8 +212,9 @@ impl Header {
 		match &mut *hash {
 			&mut Some(ref h) => h.clone(),
 			hash @ &mut None => {
-				*hash = Some(self.rlp_sha3(Seal::Without));
-				hash.as_ref().unwrap().clone()
+				let h = self.rlp_sha3(Seal::Without);
+				*hash = Some(h.clone());
+				h
 			}
 		}
 	}

ethcore/src/miner/miner.rs

@@ -136,7 +136,7 @@ impl GasPriceCalibrator {
 				let gas_per_tx: f32 = 21000.0;
 				let wei_per_gas: f32 = wei_per_usd * usd_per_tx / gas_per_tx;
 				info!(target: "miner", "Updated conversion rate to Ξ1 = {} ({} wei/gas)", Colour::White.bold().paint(format!("US${}", usd_per_eth)), Colour::Yellow.bold().paint(format!("{}", wei_per_gas)));
-				set_price(U256::from_dec_str(&format!("{:.0}", wei_per_gas)).unwrap());
+				set_price(U256::from(wei_per_gas as u64));
 			}) {
 				self.next_calibration = Instant::now() + self.options.recalibration_period;
 			} else {
@@ -747,7 +747,7 @@ impl MinerService for Miner {
 			let mut transaction_queue = self.transaction_queue.lock();
 			let import = self.add_transactions_to_queue(
 				chain, vec![transaction], TransactionOrigin::Local, &mut transaction_queue
-			).pop().unwrap();
+			).pop().expect("one result returned per added transaction; one added => one result; qed");
 
 			match import {
 				Ok(ref res) => {
@@ -869,7 +869,11 @@ impl MinerService for Miner {
 							gas_used: receipt.gas_used - prev_gas,
 							contract_address: match tx.action {
 								Action::Call(_) => None,
-								Action::Create => Some(contract_address(&tx.sender().unwrap(), &tx.nonce)),
+								Action::Create => {
+									let sender = tx.sender()
+										.expect("transactions in pending block have already been checked for valid sender; qed");
+									Some(contract_address(&sender, &tx.nonce))
+								}
 							},
 							logs: receipt.logs.clone(),
 						}

ethcore/src/miner/price_info.rs

@@ -52,7 +52,8 @@ impl<F: Fn(PriceInfo) + Sync + Send + 'static> Handler<HttpStream> for SetPriceH
 			.and_then(|json| json.find_path(&["result", "ethusd"])
 				.and_then(|obj| match *obj {
 					Json::String(ref s) => Some((self.set_price)(PriceInfo {
-						ethusd: FromStr::from_str(s).unwrap()
+						ethusd: FromStr::from_str(s)
+							.expect("Etherscan API will always return properly formatted price; qed")
 					})),
 					_ => None,
 				}));
@@ -67,10 +68,14 @@ impl PriceInfo {
 		let client = try!(Client::new().map_err(|_| ()));
 		thread::spawn(move || {
 			let (tx, rx) = mpsc::channel();
-			let _ = client.request(FromStr::from_str("http://api.etherscan.io/api?module=stats&action=ethprice").unwrap(), SetPriceHandler {
-				set_price: set_price,
-				channel: tx,
-			}).ok().and_then(|_| rx.recv().ok());
+			let url = FromStr::from_str("http://api.etherscan.io/api?module=stats&action=ethprice")
+				.expect("string known to be a valid URL; qed");
+			let _ = client.request(
+				url,
+				SetPriceHandler {
+					set_price: set_price,
+					channel: tx,
+				}).ok().and_then(|_| rx.recv().ok());
 			client.close();
 		});
 		Ok(())

ethcore/src/miner/transaction_queue.rs

@@ -700,7 +700,7 @@ impl TransactionQueue {
 			None => vec![],
 		};
 		for k in nonces_from_sender {
-			let order = self.current.drop(&sender, &k).unwrap();
+			let order = self.current.drop(&sender, &k).expect("transaction known to be in self.current; qed");
 			self.current.insert(sender, k, order.penalize());
 		}
 		// Same thing for future
@@ -709,7 +709,7 @@ impl TransactionQueue {
 			None => vec![],
 		};
 		for k in nonces_from_sender {
-			let order = self.future.drop(&sender, &k).unwrap();
+			let order = self.future.drop(&sender, &k).expect("transaction known to be in self.future; qed");
 			self.future.insert(sender, k, order.penalize());
 		}
 	}

ethcore/src/spec/spec.rs

@@ -150,7 +150,8 @@ impl Spec {
 		if self.state_root_memo.read().is_none() {
 			*self.state_root_memo.write() = Some(self.genesis_state.root());
 		}
-		self.state_root_memo.read().as_ref().unwrap().clone()
+		self.state_root_memo.read().as_ref().cloned()
+			.expect("state root memo ensured to be set at this point; qed")
 	}
 
 	/// Get the known knodes of the network in enode format.

ethcore/src/state/mod.rs

@@ -520,7 +520,7 @@ impl State {
 		}
 
 		{
-			let mut trie = factories.trie.from_existing(db.as_hashdb_mut(), root).unwrap();
+			let mut trie = try!(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 {
@@ -691,14 +691,15 @@ impl State {
 		}
 		self.note_cache(a);
 
-		match &mut self.cache.borrow_mut().get_mut(a).unwrap().account {
-			&mut Some(ref mut acc) => not_default(acc),
-			slot => *slot = Some(default()),
-		}
-
-		// at this point the account is guaranteed to be in the cache.
+		// at this point the entry is guaranteed to be in the cache.
 		RefMut::map(self.cache.borrow_mut(), |c| {
-			let mut entry = c.get_mut(a).unwrap();
+			let mut entry = c.get_mut(a).expect("entry known to exist in the cache; qed");
+
+			match &mut entry.account {
+				&mut Some(ref mut acc) => not_default(acc),
+				slot => *slot = Some(default()),
+			}
+
 			// set the dirty flag after changing account data.
 			entry.state = AccountState::Dirty;
 			match entry.account {

ethcore/src/state_db.rs

@@ -134,10 +134,11 @@ impl StateDB {
 		let hash_count_entry = db.get(COL_ACCOUNT_BLOOM, ACCOUNT_BLOOM_HASHCOUNT_KEY)
 			.expect("Low-level database error");
 
-		if hash_count_entry.is_none() {
-			return Bloom::new(ACCOUNT_BLOOM_SPACE, DEFAULT_ACCOUNT_PRESET);
-		}
-		let hash_count_bytes = hash_count_entry.unwrap();
+		let hash_count_bytes = match hash_count_entry {
+			Some(bytes) => bytes,
+			None => return Bloom::new(ACCOUNT_BLOOM_SPACE, DEFAULT_ACCOUNT_PRESET),
+		};
+
 		assert_eq!(hash_count_bytes.len(), 1);
 		let hash_count = hash_count_bytes[0];
 

ethcore/src/trace/db.rs

@@ -129,7 +129,7 @@ impl<T> TraceDB<T> where T: DatabaseExtras {
 	pub fn new(config: Config, tracesdb: Arc<Database>, extras: Arc<T>) -> Self {
 		let mut batch = DBTransaction::new(&tracesdb);
 		batch.put(db::COL_TRACE, b"version", TRACE_DB_VER);
-		tracesdb.write(batch).unwrap();
+		tracesdb.write(batch).expect("failed to update version");
 
 		TraceDB {
 			traces: RwLock::new(HashMap::new()),

ethcore/src/types/transaction.rs

@@ -21,7 +21,7 @@ use std::cell::*;
 use rlp::*;
 use util::sha3::Hashable;
 use util::{H256, Address, U256, Bytes, HeapSizeOf};
-use ethkey::{Signature, sign, Secret, Public, recover, public_to_address, Error as EthkeyError};
+use ethkey::{Signature, Secret, Public, recover, public_to_address, Error as EthkeyError};
 use error::*;
 use evm::Schedule;
 use header::BlockNumber;
@@ -143,7 +143,8 @@ impl Transaction {
 
 	/// Signs the transaction as coming from `sender`.
 	pub fn sign(self, secret: &Secret) -> SignedTransaction {
-		let sig = sign(secret, &self.hash()).unwrap();
+		let sig = ::ethkey::sign(secret, &self.hash())
+			.expect("data is valid and context has signing capabilities; qed");
 		self.with_signature(sig)
 	}
 

ethcore/src/verification/verification.rs

@@ -108,7 +108,8 @@ pub fn verify_block_family(header: &Header, bytes: &[u8], engine: &Engine, bc: &
 			match bc.block_details(&hash) {
 				Some(details) => {
 					excluded.insert(details.parent.clone());
-					let b = bc.block(&hash).unwrap();
+					let b = bc.block(&hash)
+						.expect("parent already known to be stored; qed");
 					excluded.extend(BlockView::new(&b).uncle_hashes());
 					hash = details.parent;
 				}