Light friendly dapps (#5634)

* move native_contracts ABIs to JSON files, add urlhint

* port hash-fetch to futures, fix tests

* fix dapps compilation, defer async port to later

* activate dapps server in the light client

* better formatting

Cargo.lock

@@ -1640,6 +1640,7 @@ dependencies = [
  "log 0.3.7 (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)",
+ "native-contracts 0.1.0",
  "parity-reactor 0.1.0",
  "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)",
@@ -1798,6 +1799,7 @@ dependencies = [
  "ethcore-ipc-codegen 1.7.0",
  "ethcore-util 1.7.0",
  "ethsync 1.7.0",
+ "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-common-types 1.7.0",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-hash-fetch 1.7.0",

dapps/src/apps/fetcher/mod.rs

@@ -95,6 +95,16 @@ impl<R: URLHint + 'static, F: Fetch> ContentFetcher<F, R> {
 	fn set_status(&self, content_id: &str, status: ContentStatus) {
 		self.cache.lock().insert(content_id.to_owned(), status);
 	}
+
+	// resolve contract call synchronously.
+	// TODO: port to futures-based hyper and make it all async.
+	fn resolve(&self, content_id: Vec<u8>) -> Option<URLHintResult> {
+		use futures::Future;
+
+		self.resolver.resolve(content_id)
+			.wait()
+			.unwrap_or_else(|e| { warn!("Error resolving content-id: {}", e); None })
+	}
 }
 
 impl<R: URLHint + 'static, F: Fetch> Fetcher for ContentFetcher<F, R> {
@@ -108,10 +118,8 @@ impl<R: URLHint + 'static, F: Fetch> Fetcher for ContentFetcher<F, R> {
 		}
 		// fallback to resolver
 		if let Ok(content_id) = content_id.from_hex() {
-			// else try to resolve the app_id
-			let has_content = self.resolver.resolve(content_id).is_some();
 			// if there is content or we are syncing return true
-			has_content || self.sync.is_major_importing()
+			self.sync.is_major_importing() || self.resolve(content_id).is_some()
 		} else {
 			false
 		}
@@ -137,7 +145,7 @@ impl<R: URLHint + 'static, F: Fetch> Fetcher for ContentFetcher<F, R> {
 				_ => {
 					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);
+					let content = self.resolve(content_hex);
 
 					let cache = self.cache.clone();
 					let id = content_id.clone();
@@ -225,6 +233,7 @@ mod tests {
 	use std::sync::Arc;
 	use util::Bytes;
 	use fetch::{Fetch, Client};
+	use futures::{future, Future, BoxFuture};
 	use hash_fetch::urlhint::{URLHint, URLHintResult};
 	use parity_reactor::Remote;
 
@@ -236,8 +245,8 @@ mod tests {
 	#[derive(Clone)]
 	struct FakeResolver;
 	impl URLHint for FakeResolver {
-		fn resolve(&self, _id: Bytes) -> Option<URLHintResult> {
+		fn resolve(&self, _id: Bytes) -> BoxFuture<Option<URLHintResult>, String> {
-			None
+			future::ok(None).boxed()
 		}
 	}
 

dapps/src/tests/fetch.rs

@@ -60,7 +60,7 @@ fn should_return_503_when_syncing_but_should_make_the_calls() {
 
 	// then
 	response.assert_status("HTTP/1.1 503 Service Unavailable");
-	assert_eq!(registrar.calls.lock().len(), 4);
+	assert_eq!(registrar.calls.lock().len(), 2);
 	assert_security_headers_for_embed(&response.headers);
 }
 

dapps/src/tests/helpers/registrar.rs

@@ -64,9 +64,10 @@ impl ContractClient for FakeRegistrar {
 		Ok(REGISTRAR.parse().unwrap())
 	}
 
-	fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String> {
+	fn call(&self, address: Address, data: Bytes) -> ::futures::BoxFuture<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))
+		let res = self.responses.lock().get(&call).cloned().expect(&format!("No response for call: {:?}", call));
+		Box::new(::futures::future::done(res))
 	}
 }

ethcore/native_contracts/build.rs

@@ -20,18 +20,13 @@ use std::path::Path;
 use std::fs::File;
 use std::io::Write;
 
-// TODO: `include!` these from files where they're pretty-printed?
+// TODO: just walk the "res" directory and generate whole crate automatically.
-const REGISTRY_ABI: &'static str = r#"[{"constant":true,"inputs":[{"name":"_data","type":"address"}],"name":"canReverse","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_new","type":"address"}],"name":"setOwner","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"},{"name":"_value","type":"bytes32"}],"name":"setData","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"string"}],"name":"confirmReverse","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"bytes32"}],"name":"reserve","outputs":[{"name":"success","type":"bool"}],"payable":true,"type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"bytes32"}],"name":"drop","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"getAddress","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_amount","type":"uint256"}],"name":"setFee","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_to","type":"address"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"getData","outputs":[{"name":"","type":"bytes32"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_name","type":"bytes32"}],"name":"reserved","outputs":[{"name":"reserved","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"drain","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"string"},{"name":"_who","type":"address"}],"name":"proposeReverse","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_name","type":"bytes32"}],"name":"hasReverse","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"getUint","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"fee","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_name","type":"bytes32"}],"name":"getOwner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_name","type":"bytes32"}],"name":"getReverse","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_data","type":"address"}],"name":"reverse","outputs":[{"name":"","type":"string"}],"payable":false,"type":"function"},{"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"},{"constant":false,"inputs":[{"name":"_name","type":"string"},{"name":"_who","type":"address"}],"name":"confirmReverseAs","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"removeReverse","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"},{"name":"_value","type":"address"}],"name":"setAddress","outputs":[{"name":"success","type":"bool"}],"payable":false,"type":"function"}]"#;
+const REGISTRY_ABI: &'static str = include_str!("res/registrar.json");
-
+const URLHINT_ABI: &'static str = include_str!("res/urlhint.json");
-const SERVICE_TRANSACTION_ABI: &'static str = r#"[{"constant":false,"inputs":[{"name":"_new","type":"address"}],"name":"setOwner","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_who","type":"address"}],"name":"certify","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_who","type":"address"},{"name":"_field","type":"string"}],"name":"getAddress","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_who","type":"address"}],"name":"revoke","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"delegate","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_who","type":"address"},{"name":"_field","type":"string"}],"name":"getUint","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_new","type":"address"}],"name":"setDelegate","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_who","type":"address"}],"name":"certified","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_who","type":"address"},{"name":"_field","type":"string"}],"name":"get","outputs":[{"name":"","type":"bytes32"}],"payable":false,"type":"function"}]"#;
+const SERVICE_TRANSACTION_ABI: &'static str = include_str!("res/service_transaction.json");
-
+const SECRETSTORE_ACL_STORAGE_ABI: &'static str = include_str!("res/secretstore_acl_storage.json");
-const SECRETSTORE_ACL_STORAGE_ABI: &'static str = r#"[{"constant":true,"inputs":[{"name":"user","type":"address"},{"name":"document","type":"bytes32"}],"name":"checkPermissions","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"}]"#;
+const VALIDATOR_SET_ABI: &'static str = include_str!("res/validator_set.json");
-
+const VALIDATOR_REPORT_ABI: &'static str = include_str!("res/validator_report.json");
-// be very careful changing these: ensure `ethcore/engines` validator sets have corresponding
-// changes.
-const VALIDATOR_SET_ABI: &'static str = r#"[{"constant":true,"inputs":[],"name":"transitionNonce","outputs":[{"name":"nonce","type":"uint256"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"getValidators","outputs":[{"name":"validators","type":"address[]"}],"payable":false,"type":"function"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_parent_hash","type":"bytes32"},{"indexed":true,"name":"_nonce","type":"uint256"},{"indexed":false,"name":"_new_set","type":"address[]"}],"name":"ValidatorsChanged","type":"event"}]"#;
-
-const VALIDATOR_REPORT_ABI: &'static str = r#"[{"constant":false,"inputs":[{"name":"validator","type":"address"},{"name":"blockNumber","type":"uint256"},{"name":"proof","type":"bytes"}],"name":"reportMalicious","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"validator","type":"address"},{"name":"blockNumber","type":"uint256"}],"name":"reportBenign","outputs":[],"payable":false,"type":"function"}]"#;
 
 const TEST_VALIDATOR_SET_ABI: &'static str = r#"[{"constant":true,"inputs":[],"name":"transitionNonce","outputs":[{"name":"n","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"newValidators","type":"address[]"}],"name":"setValidators","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"getValidators","outputs":[{"name":"vals","type":"address[]"}],"payable":false,"type":"function"},{"inputs":[],"payable":false,"type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_parent_hash","type":"bytes32"},{"indexed":true,"name":"_nonce","type":"uint256"},{"indexed":false,"name":"_new_set","type":"address[]"}],"name":"ValidatorsChanged","type":"event"}]"#;
 
@@ -51,6 +46,7 @@ fn build_test_contracts() {
 
 fn main() {
 	build_file("Registry", REGISTRY_ABI, "registry.rs");
+	build_file("Urlhint", URLHINT_ABI, "urlhint.rs");
 	build_file("ServiceTransactionChecker", SERVICE_TRANSACTION_ABI, "service_transaction.rs");
 	build_file("SecretStoreAclStorage", SECRETSTORE_ACL_STORAGE_ABI, "secretstore_acl_storage.rs");
 	build_file("ValidatorSet", VALIDATOR_SET_ABI, "validator_set.rs");

ethcore/native_contracts/generator/src/lib.rs

@@ -50,6 +50,8 @@ use futures::{{future, Future, IntoFuture, BoxFuture}};
 use ethabi::{{Contract, Interface, Token, Event}};
 use util::{{self, Uint}};
 
+/// Generated Rust bindings to an Ethereum contract.
+#[derive(Clone, Debug)]
 pub struct {name} {{
 	contract: Contract,
 	/// Address to make calls to.
@@ -101,6 +103,7 @@ fn generate_functions(contract: &Contract) -> Result<String, Error> {
 
 		functions.push_str(&format!(r##"
 /// Call the function "{abi_name}" on the contract.
+///
 /// Inputs: {abi_inputs:?}
 /// Outputs: {abi_outputs:?}
 pub fn {snake_name}<F, U>(&self, call: F, {params}) -> BoxFuture<{output_type}, String>
@@ -121,7 +124,7 @@ pub fn {snake_name}<F, U>(&self, call: F, {params}) -> BoxFuture<{output_type},
 	call_future
 		.into_future()
 		.and_then(move |out| function.decode_output(out).map_err(|e| format!("{{:?}}", e)))
-		.map(::std::collections::VecDeque::from)
+		.map(Vec::into_iter)
 		.and_then(|mut outputs| {decode_outputs})
 		.boxed()
 }}
@@ -174,7 +177,7 @@ fn input_params_codegen(inputs: &[ParamType]) -> Result<(String, String), ParamT
 // as a tuple, and the second gives code to get that tuple from a deque of tokens.
 //
 // produce output type of the form (type_1, type_2, ...) without trailing comma.
-// produce code for getting this output type from `outputs: VecDeque<Token>`, where
+// produce code for getting this output type from `outputs: Vec<Token>::IntoIter`, where
 // an `Err(String)` can be returned.
 //
 // returns any unsupported param type encountered.
@@ -190,7 +193,7 @@ fn output_params_codegen(outputs: &[ParamType]) -> Result<(String, String), Para
 		decode_outputs.push_str(&format!(
 			r#"
 				outputs
-					.pop_front()
+					.next()
 					.and_then(|output| {{ {} }})
 					.ok_or_else(|| "Wrong output type".to_string())?
 			"#,

ethcore/native_contracts/res/registrar.json

@@ -0,0 +1,21 @@
+[
+	{"constant":false,"inputs":[{"name":"_new","type":"address"}],"name":"setOwner","outputs":[],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"string"}],"name":"confirmReverse","outputs":[{"name":"success","type":"bool"}],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"bytes32"}],"name":"reserve","outputs":[{"name":"success","type":"bool"}],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"},{"name":"_value","type":"bytes32"}],"name":"set","outputs":[{"name":"success","type":"bool"}],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"bytes32"}],"name":"drop","outputs":[{"name":"success","type":"bool"}],"type":"function"},
+	{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"getAddress","outputs":[{"name":"","type":"address"}],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_amount","type":"uint256"}],"name":"setFee","outputs":[],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_to","type":"address"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"type":"function"},
+	{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"type":"function"},
+	{"constant":true,"inputs":[{"name":"_name","type":"bytes32"}],"name":"reserved","outputs":[{"name":"reserved","type":"bool"}],"type":"function"},
+	{"constant":false,"inputs":[],"name":"drain","outputs":[],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"string"},{"name":"_who","type":"address"}],"name":"proposeReverse","outputs":[{"name":"success","type":"bool"}],"type":"function"},
+	{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"getUint","outputs":[{"name":"","type":"uint256"}],"type":"function"},
+	{"constant":true,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"}],"name":"get","outputs":[{"name":"","type":"bytes32"}],"type":"function"},
+	{"constant":true,"inputs":[],"name":"fee","outputs":[{"name":"","type":"uint256"}],"type":"function"},
+	{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"reverse","outputs":[{"name":"","type":"string"}],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"},{"name":"_value","type":"uint256"}],"name":"setUint","outputs":[{"name":"success","type":"bool"}],"type":"function"},
+	{"constant":false,"inputs":[],"name":"removeReverse","outputs":[],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_name","type":"bytes32"},{"name":"_key","type":"string"},{"name":"_value","type":"address"}],"name":"setAddress","outputs":[{"name":"success","type":"bool"}],"type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"amount","type":"uint256"}],"name":"Drained","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"amount","type":"uint256"}],"name":"FeeChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"bytes32"},{"indexed":true,"name":"owner","type":"address"}],"name":"Reserved","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"bytes32"},{"indexed":true,"name":"oldOwner","type":"address"},{"indexed":true,"name":"newOwner","type":"address"}],"name":"Transferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"bytes32"},{"indexed":true,"name":"owner","type":"address"}],"name":"Dropped","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"bytes32"},{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"key","type":"string"}],"name":"DataChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"string"},{"indexed":true,"name":"reverse","type":"address"}],"name":"ReverseProposed","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"string"},{"indexed":true,"name":"reverse","type":"address"}],"name":"ReverseConfirmed","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"string"},{"indexed":true,"name":"reverse","type":"address"}],"name":"ReverseRemoved","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"old","type":"address"},{"indexed":true,"name":"current","type":"address"}],"name":"NewOwner","type":"event"}
+]

ethcore/native_contracts/res/secretstore_acl_storage.json

@@ -0,0 +1,3 @@
+[
+	{"constant":true,"inputs":[{"name":"user","type":"address"},{"name":"document","type":"bytes32"}],"name":"checkPermissions","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"}
+]

ethcore/native_contracts/res/service_transaction.json

@@ -0,0 +1,12 @@
+[
+	{"constant":false,"inputs":[{"name":"_new","type":"address"}],"name":"setOwner","outputs":[],"payable":false,"type":"function"},
+	{"constant":false,"inputs":[{"name":"_who","type":"address"}],"name":"certify","outputs":[],"payable":false,"type":"function"},
+	{"constant":true,"inputs":[{"name":"_who","type":"address"},{"name":"_field","type":"string"}],"name":"getAddress","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},
+	{"constant":false,"inputs":[{"name":"_who","type":"address"}],"name":"revoke","outputs":[],"payable":false,"type":"function"},
+	{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},
+	{"constant":true,"inputs":[],"name":"delegate","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},
+	{"constant":true,"inputs":[{"name":"_who","type":"address"},{"name":"_field","type":"string"}],"name":"getUint","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},
+	{"constant":false,"inputs":[{"name":"_new","type":"address"}],"name":"setDelegate","outputs":[],"payable":false,"type":"function"},
+	{"constant":true,"inputs":[{"name":"_who","type":"address"}],"name":"certified","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},
+	{"constant":true,"inputs":[{"name":"_who","type":"address"},{"name":"_field","type":"string"}],"name":"get","outputs":[{"name":"","type":"bytes32"}],"payable":false,"type":"function"}
+]

ethcore/native_contracts/res/urlhint.json

@@ -0,0 +1,6 @@
+[
+	{"constant":false,"inputs":[{"name":"_content","type":"bytes32"},{"name":"_url","type":"string"}],"name":"hintURL","outputs":[],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_content","type":"bytes32"},{"name":"_accountSlashRepo","type":"string"},{"name":"_commit","type":"bytes20"}],"name":"hint","outputs":[],"type":"function"},
+	{"constant":true,"inputs":[{"name":"","type":"bytes32"}],"name":"entries","outputs":[{"name":"accountSlashRepo","type":"string"},{"name":"commit","type":"bytes20"},{"name":"owner","type":"address"}],"type":"function"},
+	{"constant":false,"inputs":[{"name":"_content","type":"bytes32"}],"name":"unhint","outputs":[],"type":"function"}
+]

ethcore/native_contracts/res/validator_report.json

@@ -0,0 +1,4 @@
+[
+	{"constant":false,"inputs":[{"name":"validator","type":"address"},{"name":"blockNumber","type":"uint256"},{"name":"proof","type":"bytes"}],"name":"reportMalicious","outputs":[],"payable":false,"type":"function"},
+	{"constant":false,"inputs":[{"name":"validator","type":"address"},{"name":"blockNumber","type":"uint256"}],"name":"reportBenign","outputs":[],"payable":false,"type":"function"}
+]

ethcore/native_contracts/res/validator_set.json

@@ -0,0 +1,5 @@
+[
+	{"constant":true,"inputs":[],"name":"transitionNonce","outputs":[{"name":"nonce","type":"uint256"}],"payable":false,"type":"function"},
+	{"constant":true,"inputs":[],"name":"getValidators","outputs":[{"name":"validators","type":"address[]"}],"payable":false,"type":"function"},
+	{"anonymous":false,"inputs":[{"indexed":true,"name":"_parent_hash","type":"bytes32"},{"indexed":true,"name":"_nonce","type":"uint256"},{"indexed":false,"name":"_new_set","type":"address[]"}],"name":"ValidatorsChanged","type":"event"}
+]

ethcore/native_contracts/src/lib.rs

@@ -24,6 +24,7 @@ extern crate ethabi;
 extern crate ethcore_util as util;
 
 mod registry;
+mod urlhint;
 mod service_transaction;
 mod secretstore_acl_storage;
 mod validator_set;
@@ -32,6 +33,7 @@ mod validator_report;
 pub mod test_contracts;
 
 pub use self::registry::Registry;
+pub use self::urlhint::Urlhint;
 pub use self::service_transaction::ServiceTransactionChecker;
 pub use self::secretstore_acl_storage::SecretStoreAclStorage;
 pub use self::validator_set::ValidatorSet;

ethcore/native_contracts/src/urlhint.rs

@@ -0,0 +1,22 @@
+// Copyright 2015-2017 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/>.
+
+#![allow(unused_mut, unused_variables, unused_imports)]
+
+//! Registrar contract: maps names to arbitrary URL.
+// TODO: testing.
+
+include!(concat!(env!("OUT_DIR"), "/urlhint.rs"));

hash-fetch/Cargo.toml

@@ -7,7 +7,7 @@ version = "1.7.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 
 [dependencies]
-ethabi = "1.0.0"
+ethabi = "1.0.4"
 futures = "0.1"
 log = "0.3"
 mime = "0.2"
@@ -17,3 +17,4 @@ rustc-serialize = "0.3"
 fetch = { path = "../util/fetch" }
 ethcore-util = { path = "../util" }
 parity-reactor = { path = "../util/reactor" }
+native-contracts = { path = "../ethcore/native_contracts" }

hash-fetch/src/client.rs

@@ -87,55 +87,7 @@ impl From<io::Error> for Error {
 	}
 }
 
-/// Default Hash-fetching client using on-chain contract to resolve hashes to URLs.
+fn validate_hash(path: PathBuf, hash: H256, result: Result<Response, FetchError>) -> Result<PathBuf, Error> {
-pub struct Client<F: Fetch + 'static = FetchClient> {
-	contract: URLHintContract,
-	fetch: F,
-	remote: Remote,
-	random_path: Arc<Fn() -> PathBuf + Sync + Send>,
-}
-
-impl Client {
-	/// Creates new instance of the `Client` given on-chain contract client and task runner.
-	pub fn new(contract: Arc<ContractClient>, remote: Remote) -> Self {
-		Client::with_fetch(contract, FetchClient::new().unwrap(), remote)
-	}
-}
-
-impl<F: Fetch + 'static> Client<F> {
-
-	/// Creates new instance of the `Client` given on-chain contract client, fetch service and task runner.
-	pub fn with_fetch(contract: Arc<ContractClient>, fetch: F, remote: Remote) -> Self {
-		Client {
-			contract: URLHintContract::new(contract),
-			fetch: fetch,
-			remote: remote,
-			random_path: Arc::new(random_temp_path),
-		}
-	}
-}
-
-impl<F: Fetch + 'static> HashFetch for Client<F> {
-	fn fetch(&self, hash: H256, on_done: Box<Fn(Result<PathBuf, Error>) + Send>) {
-		debug!(target: "fetch", "Fetching: {:?}", hash);
-
-		let url = self.contract.resolve(hash.to_vec()).map(|content| match content {
-				URLHintResult::Dapp(dapp) => {
-					dapp.url()
-				},
-				URLHintResult::Content(content) => {
-					content.url
-				},
-		}).ok_or_else(|| Error::NoResolution);
-
-		debug!(target: "fetch", "Resolved {:?} to {:?}. Fetching...", hash, url);
-
-		match url {
-			Err(err) => on_done(Err(err)),
-			Ok(url) => {
-				let random_path = self.random_path.clone();
-				let future = self.fetch.fetch(&url).then(move |result| {
-					fn validate_hash(path: PathBuf, hash: H256, result: Result<Response, FetchError>) -> Result<PathBuf, Error> {
 	let response = result?;
 	if !response.is_success() {
 		return Err(Error::InvalidStatus);
@@ -155,8 +107,55 @@ impl<F: Fetch + 'static> HashFetch for Client<F> {
 	} else {
 		Ok(path)
 	}
-					}
+}
 
+/// Default Hash-fetching client using on-chain contract to resolve hashes to URLs.
+pub struct Client<F: Fetch + 'static = FetchClient> {
+	contract: URLHintContract,
+	fetch: F,
+	remote: Remote,
+	random_path: Arc<Fn() -> PathBuf + Sync + Send>,
+}
+
+impl Client {
+	/// Creates new instance of the `Client` given on-chain contract client and task runner.
+	pub fn new(contract: Arc<ContractClient>, remote: Remote) -> Self {
+		Client::with_fetch(contract, FetchClient::new().unwrap(), remote)
+	}
+}
+
+impl<F: Fetch + 'static> Client<F> {
+	/// Creates new instance of the `Client` given on-chain contract client, fetch service and task runner.
+	pub fn with_fetch(contract: Arc<ContractClient>, fetch: F, remote: Remote) -> Self {
+		Client {
+			contract: URLHintContract::new(contract),
+			fetch: fetch,
+			remote: remote,
+			random_path: Arc::new(random_temp_path),
+		}
+	}
+}
+
+impl<F: Fetch + 'static> HashFetch for Client<F> {
+	fn fetch(&self, hash: H256, on_done: Box<Fn(Result<PathBuf, Error>) + Send>) {
+		debug!(target: "fetch", "Fetching: {:?}", hash);
+
+		let random_path = self.random_path.clone();
+		let remote_fetch = self.fetch.clone();
+		let future = self.contract.resolve(hash.to_vec())
+			.map_err(|e| { warn!("Error resolving URL: {}", e); Error::NoResolution })
+			.and_then(|maybe_url| maybe_url.ok_or(Error::NoResolution))
+			.map(|content| match content {
+					URLHintResult::Dapp(dapp) => {
+						dapp.url()
+					},
+					URLHintResult::Content(content) => {
+						content.url
+					},
+			})
+			.and_then(move |url| {
+				debug!(target: "fetch", "Resolved {:?} to {:?}. Fetching...", hash, url);
+				let future = remote_fetch.fetch(&url).then(move |result| {
 					debug!(target: "fetch", "Content fetched, validating hash ({:?})", hash);
 					let path = random_path();
 					let res = validate_hash(path.clone(), hash, result);
@@ -165,13 +164,13 @@ impl<F: Fetch + 'static> HashFetch for Client<F> {
 						// Remove temporary file in case of error
 						let _ = fs::remove_file(&path);
 					}
-					on_done(res);
+					res
-
-					Ok(()) as Result<(), ()>
 				});
-				self.remote.spawn(self.fetch.process(future));
+				remote_fetch.process(future)
-			},
+			})
-		}
+			.then(move |res| { on_done(res); Ok(()) as Result<(), ()> });
+
+		self.remote.spawn(future);
 	}
 }
 
@@ -225,7 +224,7 @@ mod tests {
 		let mut registrar = FakeRegistrar::new();
 		registrar.responses = Mutex::new(vec![
 			Ok(format!("000000000000000000000000{}", URLHINT).from_hex().unwrap()),
-			Ok("00000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000deadcafebeefbeefcafedeaddeedfeedffffffff000000000000000000000000000000000000000000000000000000000000003d68747470733a2f2f657468636f72652e696f2f6173736574732f696d616765732f657468636f72652d626c61636b2d686f72697a6f6e74616c2e706e67000000".from_hex().unwrap()),
+			Ok("00000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000deadcafebeefbeefcafedeaddeedfeedffffffff000000000000000000000000000000000000000000000000000000000000003c68747470733a2f2f7061726974792e696f2f6173736574732f696d616765732f657468636f72652d626c61636b2d686f72697a6f6e74616c2e706e6700000000".from_hex().unwrap()),
 		]);
 		registrar
 	}

hash-fetch/src/lib.rs

@@ -25,12 +25,14 @@ extern crate mime;
 
 extern crate ethabi;
 extern crate ethcore_util as util;
-pub extern crate fetch;
 extern crate futures;
 extern crate mime_guess;
+extern crate native_contracts;
+extern crate parity_reactor;
 extern crate rand;
 extern crate rustc_serialize;
-extern crate parity_reactor;
+
+pub extern crate fetch;
 
 mod client;
 

hash-fetch/src/urlhint.rs

@@ -16,13 +16,13 @@
 
 //! URLHint Contract
 
-use std::fmt;
 use std::sync::Arc;
 use rustc_serialize::hex::ToHex;
 use mime::Mime;
 use mime_guess;
 
-use ethabi::{Interface, Contract, Token};
+use futures::{future, BoxFuture, Future};
+use native_contracts::{Registry, Urlhint};
 use util::{Address, Bytes, Hashable};
 
 const COMMIT_LEN: usize = 20;
@@ -33,7 +33,7 @@ pub trait ContractClient: Send + Sync {
 	/// Get registrar address
 	fn registrar(&self) -> Result<Address, String>;
 	/// Call Contract
-	fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String>;
+	fn call(&self, address: Address, data: Bytes) -> BoxFuture<Bytes, String>;
 }
 
 /// Github-hosted dapp.
@@ -44,7 +44,7 @@ pub struct GithubApp {
 	/// Github Repository
 	pub repo: String,
 	/// Commit on Github
-	pub commit: [u8;COMMIT_LEN],
+	pub commit: [u8; COMMIT_LEN],
 	/// Dapp owner address
 	pub owner: Address,
 }
@@ -94,91 +94,31 @@ pub enum URLHintResult {
 /// URLHint Contract interface
 pub trait URLHint: Send + Sync {
 	/// Resolves given id to registrar entry.
-	fn resolve(&self, id: Bytes) -> Option<URLHintResult>;
+	fn resolve(&self, id: Bytes) -> BoxFuture<Option<URLHintResult>, String>;
 }
 
 /// `URLHintContract` API
 #[derive(Clone)]
 pub struct URLHintContract {
-	urlhint: Contract,
+	urlhint: Arc<Urlhint>,
-	registrar: Contract,
+	registrar: Registry,
 	client: Arc<ContractClient>,
 }
 
 impl URLHintContract {
 	/// Creates new `URLHintContract`
 	pub fn new(client: Arc<ContractClient>) -> Self {
-		let urlhint = Interface::load(include_bytes!("../res/urlhint.json")).expect("urlhint.json is valid ABI");
-		let registrar = Interface::load(include_bytes!("../res/registrar.json")).expect("registrar.json is valid ABI");
-
 		URLHintContract {
-			urlhint: Contract::new(urlhint),
+			urlhint: Arc::new(Urlhint::new(Default::default())),
-			registrar: Contract::new(registrar),
+			registrar: Registry::new(Default::default()),
 			client: client,
 		}
 	}
+}
 
-	fn urlhint_address(&self) -> Option<Address> {
+fn decode_urlhint_output(output: (String, ::util::H160, Address)) -> Option<URLHintResult> {
-		let res = || {
+	let (account_slash_repo, commit, owner) = output;
-			let get_address = self.registrar.function("getAddress".into()).map_err(as_string)?;
-			let params = get_address.encode_call(
-					vec![Token::FixedBytes((*"githubhint".sha3()).to_vec()), Token::String("A".into())]
-			).map_err(as_string)?;
-			let output = self.client.call(self.client.registrar()?, params)?;
-			let result = get_address.decode_output(output).map_err(as_string)?;
 
-			match result.get(0) {
-				Some(&Token::Address(address)) if address != *Address::default() => Ok(address.into()),
-				Some(&Token::Address(_)) => Err(format!("Contract not found.")),
-				e => Err(format!("Invalid result: {:?}", e)),
-			}
-		};
-
-		match res() {
-			Ok(res) => Some(res),
-			Err(e) => {
-				warn!(target: "dapps", "Error while calling registrar: {:?}", e);
-				None
-			}
-		}
-	}
-
-	fn encode_urlhint_call(&self, id: Bytes) -> Option<Bytes> {
-		let call = self.urlhint
-			.function("entries".into())
-			.and_then(|f| f.encode_call(vec![Token::FixedBytes(id)]));
-
-		match call {
-			Ok(res) => {
-				Some(res)
-			},
-			Err(e) => {
-				warn!(target: "dapps", "Error while encoding urlhint call: {:?}", e);
-				None
-			}
-		}
-	}
-
-	fn decode_urlhint_output(&self, output: Bytes) -> Option<URLHintResult> {
-		trace!(target: "dapps", "Output: {:?}", output.to_hex());
-		let output = self.urlhint
-			.function("entries".into())
-			.and_then(|f| f.decode_output(output));
-
-		if let Ok(vec) = output {
-			if vec.len() != 3 {
-				warn!(target: "dapps", "Invalid contract output: {:?}", vec);
-				return None;
-			}
-
-			let mut it = vec.into_iter();
-			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)) => {
-					let owner = owner.into();
 	if owner == Address::default() {
 		return None;
 	}
@@ -207,33 +147,38 @@ impl URLHintContract {
 		commit: commit,
 		owner: owner,
 	}))
-				},
-				e => {
-					warn!(target: "dapps", "Invalid contract output parameters: {:?}", e);
-					None
-				},
-			}
-		} else {
-			warn!(target: "dapps", "Invalid contract output: {:?}", output);
-			None
-		}
-	}
 }
 
 impl URLHint for URLHintContract {
-	fn resolve(&self, id: Bytes) -> Option<URLHintResult> {
+	fn resolve(&self, id: Bytes) -> BoxFuture<Option<URLHintResult>, String> {
-		self.urlhint_address().and_then(|address| {
+		use futures::future::Either;
-			// Prepare contract call
+
-			self.encode_urlhint_call(id)
+		let do_call = |_, data| {
-				.and_then(|data| {
+			let addr = match self.client.registrar() {
-					let call = self.client.call(address, data);
+				Ok(addr) => addr,
-					if let Err(ref e) = call {
+				Err(e) => return future::err(e).boxed(),
-						warn!(target: "dapps", "Error while calling urlhint: {:?}", e);
+			};
+
+			self.client.call(addr, data)
+		};
+
+		let urlhint = self.urlhint.clone();
+		let client = self.client.clone();
+		self.registrar.get_address(do_call, "githubhint".sha3(), "A".into())
+			.map(|addr| if addr == Address::default() { None } else { Some(addr) })
+			.and_then(move |address| {
+				let mut fixed_id = [0; 32];
+				let len = ::std::cmp::min(32, id.len());
+				fixed_id[..len].copy_from_slice(&id[..len]);
+
+				match address {
+					None => Either::A(future::ok(None)),
+					Some(address) => {
+						let do_call = move |_, data| client.call(address, data);
+						Either::B(urlhint.entries(do_call, ::util::H256(fixed_id)).map(decode_urlhint_output))
 					}
-					call.ok()
+				}
-				})
+			}).boxed()
-				.and_then(|output| self.decode_urlhint_output(output))
-		})
 	}
 }
 
@@ -260,16 +205,14 @@ fn guess_mime_type(url: &str) -> Option<Mime> {
 	})
 }
 
-fn as_string<T: fmt::Debug>(e: T) -> String {
-	format!("{:?}", e)
-}
-
 #[cfg(test)]
 pub mod tests {
 	use std::sync::Arc;
 	use std::str::FromStr;
 	use rustc_serialize::hex::FromHex;
 
+	use futures::{BoxFuture, Future, IntoFuture};
+
 	use super::*;
 	use super::guess_mime_type;
 	use util::{Bytes, Address, Mutex, ToPretty};
@@ -297,14 +240,14 @@ pub mod tests {
 	}
 
 	impl ContractClient for FakeRegistrar {
-
 		fn registrar(&self) -> Result<Address, String> {
 			Ok(REGISTRAR.parse().unwrap())
 		}
 
-		fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String> {
+		fn call(&self, address: Address, data: Bytes) -> BoxFuture<Bytes, String> {
 			self.calls.lock().push((address.to_hex(), data.to_hex()));
-			self.responses.lock().remove(0)
+			let res = self.responses.lock().remove(0);
+			res.into_future().boxed()
 		}
 	}
 
@@ -312,11 +255,19 @@ pub mod tests {
 	fn should_call_registrar_and_urlhint_contracts() {
 		// given
 		let registrar = FakeRegistrar::new();
+		let resolve_result = {
+			use ethabi::{Encoder, Token};
+			Encoder::encode(vec![Token::String(String::new()), Token::FixedBytes(vec![0; 20]), Token::Address([0; 20])])
+		};
+		registrar.responses.lock()[1] = Ok(resolve_result);
+
 		let calls = registrar.calls.clone();
 		let urlhint = URLHintContract::new(Arc::new(registrar));
 
+
+
 		// when
-		let res = urlhint.resolve("test".bytes().collect());
+		let res = urlhint.resolve("test".bytes().collect()).wait().unwrap();
 		let calls = calls.lock();
 		let call0 = calls.get(0).expect("Registrar resolve called");
 		let call1 = calls.get(1).expect("URLHint Resolve called");
@@ -344,7 +295,7 @@ pub mod tests {
 		let urlhint = URLHintContract::new(Arc::new(registrar));
 
 		// when
-		let res = urlhint.resolve("test".bytes().collect());
+		let res = urlhint.resolve("test".bytes().collect()).wait().unwrap();
 
 		// then
 		assert_eq!(res, Some(URLHintResult::Dapp(GithubApp {
@@ -361,12 +312,12 @@ pub mod tests {
 		let mut registrar = FakeRegistrar::new();
 		registrar.responses = Mutex::new(vec![
 			Ok(format!("000000000000000000000000{}", URLHINT).from_hex().unwrap()),
-			Ok("00000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000deadcafebeefbeefcafedeaddeedfeedffffffff000000000000000000000000000000000000000000000000000000000000003d68747470733a2f2f657468636f72652e696f2f6173736574732f696d616765732f657468636f72652d626c61636b2d686f72697a6f6e74616c2e706e67000000".from_hex().unwrap()),
+			Ok("00000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000deadcafebeefbeefcafedeaddeedfeedffffffff000000000000000000000000000000000000000000000000000000000000003c68747470733a2f2f7061726974792e696f2f6173736574732f696d616765732f657468636f72652d626c61636b2d686f72697a6f6e74616c2e706e6700000000".from_hex().unwrap()),
 		]);
 		let urlhint = URLHintContract::new(Arc::new(registrar));
 
 		// when
-		let res = urlhint.resolve("test".bytes().collect());
+		let res = urlhint.resolve("test".bytes().collect()).wait().unwrap();
 
 		// then
 		assert_eq!(res, Some(URLHintResult::Content(Content {

parity/dapps.rs

@@ -20,12 +20,16 @@ use std::sync::Arc;
 use dir::default_data_path;
 use ethcore::client::{Client, BlockChainClient, BlockId};
 use ethcore::transaction::{Transaction, Action};
+use ethsync::LightSync;
+use futures::{future, IntoFuture, Future, BoxFuture};
 use hash_fetch::fetch::Client as FetchClient;
 use hash_fetch::urlhint::ContractClient;
 use helpers::replace_home;
+use light::client::Client as LightClient;
+use light::on_demand::{self, OnDemand};
 use rpc_apis::SignerService;
 use parity_reactor;
-use util::{Bytes, Address, U256};
+use util::{Bytes, Address};
 
 #[derive(Debug, PartialEq, Clone)]
 pub struct Configuration {
@@ -60,23 +64,62 @@ impl ContractClient for FullRegistrar {
 			 })
 	}
 
-	fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String> {
+	fn call(&self, address: Address, data: Bytes) -> BoxFuture<Bytes, String> {
-		let from = Address::default();
+		self.client.call_contract(BlockId::Latest, address, data)
-		let transaction = Transaction {
+			.into_future()
-			nonce: self.client.latest_nonce(&from),
+			.boxed()
-			action: Action::Call(address),
+	}
-			gas: U256::from(50_000_000),
+}
-			gas_price: U256::default(),
-			value: U256::default(),
-			data: data,
-		}.fake_sign(from);
 
-		self.client.call(&transaction, BlockId::Latest, Default::default())
+/// Registrar implementation for the light client.
-			.map_err(|e| format!("{:?}", e))
+pub struct LightRegistrar {
-			.map(|executed| {
+	/// The light client.
-				executed.output
+	pub client: Arc<LightClient>,
+	/// Handle to the on-demand service.
+	pub on_demand: Arc<OnDemand>,
+	/// Handle to the light network service.
+	pub sync: Arc<LightSync>,
+}
+
+impl ContractClient for LightRegistrar {
+	fn registrar(&self) -> Result<Address, String> {
+		self.client.engine().additional_params().get("registrar")
+			 .ok_or_else(|| "Registrar not defined.".into())
+			 .and_then(|registrar| {
+				 registrar.parse().map_err(|e| format!("Invalid registrar address: {:?}", e))
 			 })
 	}
+
+	fn call(&self, address: Address, data: Bytes) -> BoxFuture<Bytes, String> {
+		let (header, env_info) = (self.client.best_block_header(), self.client.latest_env_info());
+
+		let maybe_future = self.sync.with_context(move |ctx| {
+			self.on_demand
+				.transaction_proof(ctx, on_demand::request::TransactionProof {
+					tx: Transaction {
+						nonce: self.client.engine().account_start_nonce(),
+						action: Action::Call(address),
+						gas: 50_000_000.into(),
+						gas_price: 0.into(),
+						value: 0.into(),
+						data: data,
+					}.fake_sign(Address::default()),
+					header: header,
+					env_info: env_info,
+					engine: self.client.engine().clone(),
+				})
+				.then(|res| match res {
+					Ok(Ok(executed)) => Ok(executed.output),
+					Ok(Err(e)) => Err(format!("Failed to execute transaction: {}", e)),
+					Err(_) => Err(format!("On-demand service dropped request unexpectedly.")),
+				})
+		});
+
+		match maybe_future {
+			Some(fut) => fut.boxed(),
+			None => future::err("cannot query registry: network disabled".into()).boxed(),
+		}
+	}
 }
 
 // TODO: light client implementation forwarding to OnDemand and waiting for future

parity/run.rs

@@ -279,7 +279,7 @@ fn execute_light(cmd: RunCmd, can_restart: bool, logger: Arc<RotatingLogger>) ->
 		secret_store: account_provider,
 		logger: logger,
 		settings: Arc::new(cmd.net_settings),
-		on_demand: on_demand,
+		on_demand: on_demand.clone(),
 		cache: cache,
 		transaction_queue: txq,
 		dapps_interface: match cmd.dapps_conf.enabled {
@@ -290,7 +290,7 @@ fn execute_light(cmd: RunCmd, can_restart: bool, logger: Arc<RotatingLogger>) ->
 			true => Some(cmd.http_conf.port),
 			false => None,
 		},
-		fetch: fetch,
+		fetch: fetch.clone(),
 		geth_compatibility: cmd.geth_compatibility,
 		remote: event_loop.remote(),
 	});
@@ -301,9 +301,29 @@ fn execute_light(cmd: RunCmd, can_restart: bool, logger: Arc<RotatingLogger>) ->
 		stats: rpc_stats.clone(),
 	};
 
+	// the dapps server
+	let dapps_deps = {
+		let contract_client = Arc::new(::dapps::LightRegistrar {
+			client: service.client().clone(),
+			sync: light_sync.clone(),
+			on_demand: on_demand,
+		});
+
+		let sync = light_sync.clone();
+		dapps::Dependencies {
+			sync_status: Arc::new(move || sync.is_major_importing()),
+			contract_client: contract_client,
+			remote: event_loop.raw_remote(),
+			fetch: fetch,
+			signer: deps_for_rpc_apis.signer_service.clone(),
+		}
+	};
+
+	let dapps_middleware = dapps::new(cmd.dapps_conf.clone(), dapps_deps)?;
+
 	// start rpc servers
 	let _ws_server = rpc::new_ws(cmd.ws_conf, &dependencies)?;
-	let _http_server = rpc::new_http(cmd.http_conf.clone(), &dependencies, None)?;
+	let _http_server = rpc::new_http(cmd.http_conf.clone(), &dependencies, dapps_middleware)?;
 	let _ipc_server = rpc::new_ipc(cmd.ipc_conf, &dependencies)?;
 
 	// the signer server
@@ -315,8 +335,6 @@ fn execute_light(cmd: RunCmd, can_restart: bool, logger: Arc<RotatingLogger>) ->
 	let signing_queue = deps_for_rpc_apis.signer_service.queue();
 	let _signer_server = signer::start(cmd.signer_conf.clone(), signing_queue, signer_deps)?;
 
-	// TODO: Dapps
-
 	// minimal informant thread. Just prints block number every 5 seconds.
 	// TODO: integrate with informant.rs
 	let informant_client = service.client().clone();

updater/Cargo.toml

@@ -16,6 +16,7 @@ target_info = "0.1"
 ethcore = { path = "../ethcore" }
 ethsync = { path = "../sync" }
 ethcore-util = { path = "../util" }
+futures = "0.1"
 parity-hash-fetch = { path = "../hash-fetch" }
 ipc-common-types = { path = "../ipc-common-types" }
 ethcore-ipc = { path = "../ipc/rpc" }

updater/src/lib.rs

@@ -24,6 +24,7 @@ extern crate ethcore;
 extern crate ethabi;
 extern crate ethsync;
 extern crate ethcore_ipc as ipc;
+extern crate futures;
 extern crate target_info;
 extern crate parity_reactor;
 extern crate path;

updater/src/updater.rs

@@ -14,23 +14,25 @@
 // 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, Weak};
 use std::fs;
 use std::io::Write;
 use std::path::{PathBuf};
-use target_info::Target;
+use std::sync::{Arc, Weak};
-use util::misc;
+
-use ipc_common_types::{VersionInfo, ReleaseTrack};
-use path::restrict_permissions_owner;
-use util::{Address, H160, H256, Mutex, Bytes};
-use ethsync::{SyncProvider};
 use ethcore::client::{BlockId, BlockChainClient, ChainNotify};
+use ethsync::{SyncProvider};
+use futures::{future, Future, BoxFuture};
 use hash_fetch::{self as fetch, HashFetch};
 use hash_fetch::fetch::Client as FetchService;
+use ipc_common_types::{VersionInfo, ReleaseTrack};
 use operations::Operations;
 use parity_reactor::Remote;
+use path::restrict_permissions_owner;
 use service::{Service};
+use target_info::Target;
 use types::all::{ReleaseInfo, OperationsInfo, CapState};
+use util::{Address, H160, H256, Mutex, Bytes};
+use util::misc;
 
 /// Filter for releases.
 #[derive(Debug, Eq, PartialEq, Clone)]
@@ -338,9 +340,12 @@ impl fetch::urlhint::ContractClient for Updater {
 			.ok_or_else(|| "Registrar not available".into())
 	}
 
-	fn call(&self, address: Address, data: Bytes) -> Result<Bytes, String> {
+	fn call(&self, address: Address, data: Bytes) -> BoxFuture<Bytes, String> {
-		self.client.upgrade().ok_or_else(|| "Client not available".to_owned())?
+		future::done(
-			.call_contract(BlockId::Latest, address, data)
+			self.client.upgrade()
+				.ok_or_else(|| "Client not available".into())
+				.and_then(move |c| c.call_contract(BlockId::Latest, address, data))
+		).boxed()
 	}
 }