proved execution future

ethcore/light/src/client/mod.rs

@@ -230,22 +230,32 @@ impl Client {
 	}
 
 	/// Get a handle to the verification engine.
-	pub fn engine(&self) -> &Engine {
+	pub fn engine(&self) -> &Arc<Engine> {
-		&*self.engine
+		&self.engine
 	}
 
-	fn latest_env_info(&self) -> EnvInfo {
+	/// Get the latest environment info.
-		let header = self.best_block_header();
+	pub fn latest_env_info(&self) -> EnvInfo {
+		self.env_info(BlockId::Latest)
+			.expect("Best block header and recent hashes always stored; qed")
+	}
 
-		EnvInfo {
+	/// Get environment info for a given block.
+	pub fn env_info(&self, id: BlockId) -> Option<EnvInfo> {
+		let header = match self.block_header(id) {
+			Some(hdr) => hdr,
+			None => return None,
+		};
+
+		Some(EnvInfo {
 			number: header.number(),
 			author: header.author(),
 			timestamp: header.timestamp(),
 			difficulty: header.difficulty(),
-			last_hashes: self.build_last_hashes(header.hash()),
+			last_hashes: self.build_last_hashes(header.parent_hash()),
 			gas_used: Default::default(),
 			gas_limit: header.gas_limit(),
-		}
+		})
 	}
 
 	fn build_last_hashes(&self, mut parent_hash: H256) -> Arc<Vec<H256>> {

rpc/src/v1/helpers/dispatch.rs

@@ -158,6 +158,54 @@ impl<C: MiningBlockChainClient, M: MinerService> Dispatcher for FullDispatcher<C
 	}
 }
 
+/// Get a recent gas price corpus.
+// TODO: this could be `impl Trait`.
+pub fn fetch_gas_price_corpus(
+	sync: Arc<LightSync>,
+	client: Arc<LightChainClient>,
+	on_demand: Arc<OnDemand>,
+	cache: Arc<Mutex<LightDataCache>>,
+) -> BoxFuture<Corpus<U256>, Error> {
+	const GAS_PRICE_SAMPLE_SIZE: usize = 100;
+
+	if let Some(cached) = cache.lock().gas_price_corpus() {
+		return future::ok(cached).boxed()
+	}
+
+	let cache = cache.clone();
+	let eventual_corpus = sync.with_context(|ctx| {
+		// get some recent headers with gas used,
+		// and request each of the blocks from the network.
+		let block_futures = client.ancestry_iter(BlockId::Latest)
+			.filter(|hdr| hdr.gas_used() != U256::default())
+			.take(GAS_PRICE_SAMPLE_SIZE)
+			.map(request::Body::new)
+			.map(|req| on_demand.block(ctx, req));
+
+		// as the blocks come in, collect gas prices into a vector
+		stream::futures_unordered(block_futures)
+			.fold(Vec::new(), |mut v, block| {
+				for t in block.transaction_views().iter() {
+					v.push(t.gas_price())
+				}
+
+				future::ok(v)
+			})
+			.map(move |v| {
+				// produce a corpus from the vector, cache it, and return
+				// the median as the intended gas price.
+				let corpus: ::stats::Corpus<_> = v.into();
+				cache.lock().set_gas_price_corpus(corpus.clone());
+				corpus
+			})
+	});
+
+	match eventual_corpus {
+		Some(corp) => corp.map_err(|_| errors::no_light_peers()).boxed(),
+		None => future::err(errors::network_disabled()).boxed(),
+	}
+}
+
 /// Dispatcher for light clients -- fetches default gas price, next nonce, etc. from network.
 /// Light client `ETH` RPC.
 #[derive(Clone)]
@@ -197,44 +245,12 @@ impl LightDispatcher {
 	/// Get a recent gas price corpus.
 	// TODO: this could be `impl Trait`.
 	pub fn gas_price_corpus(&self) -> BoxFuture<Corpus<U256>, Error> {
-		const GAS_PRICE_SAMPLE_SIZE: usize = 100;
+		fetch_gas_price_corpus(
-
+			self.sync.clone(),
-		if let Some(cached) = self.cache.lock().gas_price_corpus() {
+			self.client.clone(),
-			return future::ok(cached).boxed()
+			self.on_demand.clone(),
-		}
+			self.cache.clone(),
-
+		)
-		let cache = self.cache.clone();
-		let eventual_corpus = self.sync.with_context(|ctx| {
-			// get some recent headers with gas used,
-			// and request each of the blocks from the network.
-			let block_futures = self.client.ancestry_iter(BlockId::Latest)
-				.filter(|hdr| hdr.gas_used() != U256::default())
-				.take(GAS_PRICE_SAMPLE_SIZE)
-				.map(request::Body::new)
-				.map(|req| self.on_demand.block(ctx, req));
-
-			// as the blocks come in, collect gas prices into a vector
-			stream::futures_unordered(block_futures)
-				.fold(Vec::new(), |mut v, block| {
-					for t in block.transaction_views().iter() {
-						v.push(t.gas_price())
-					}
-
-					future::ok(v)
-				})
-				.map(move |v| {
-					// produce a corpus from the vector, cache it, and return
-					// the median as the intended gas price.
-					let corpus: ::stats::Corpus<_> = v.into();
-					cache.lock().set_gas_price_corpus(corpus.clone());
-					corpus
-				})
-		});
-
-		match eventual_corpus {
-			Some(corp) => corp.map_err(|_| errors::no_light_peers()).boxed(),
-			None => future::err(errors::network_disabled()).boxed(),
-		}
 	}
 
 	/// Get an account's next nonce.
@@ -285,7 +301,12 @@ impl Dispatcher for LightDispatcher {
 		// fast path for known gas price.
 		match request_gas_price {
 			Some(gas_price) => future::ok(with_gas_price(gas_price)).boxed(),
-			None => self.gas_price_corpus().and_then(|corp| match corp.median() {
+			None => fetch_gas_price_corpus(
+				self.sync.clone(),
+				self.client.clone(),
+				self.on_demand.clone(),
+				self.cache.clone()
+			).and_then(|corp| match corp.median() {
 				Some(median) => future::ok(*median),
 				None => future::ok(DEFAULT_GAS_PRICE), // fall back to default on error.
 			}).map(with_gas_price).boxed()

rpc/src/v1/impls/eth.rs

@@ -629,10 +629,13 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 
 	fn call(&self, request: CallRequest, num: Trailing<BlockNumber>) -> BoxFuture<Bytes, Error> {
 		let request = CallRequest::into(request);
-		let signed = self.sign_call(request)?;
+		let signed = match self.sign_call(request) {
+			Ok(signed) => signed,
+			Err(e) => return future::err(e).boxed(),
+		};
 
 		let result = match num.0 {
-			BlockNumber::Pending => take_weakf!(self.miner).call(&*take_weak!(self.client), &signed, Default::default()),
+			BlockNumber::Pending => take_weakf!(self.miner).call(&*take_weakf!(self.client), &signed, Default::default()),
 			num => take_weakf!(self.client).call(&signed, num.into(), Default::default()),
 		};
 
@@ -644,7 +647,10 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 
 	fn estimate_gas(&self, request: CallRequest, num: Trailing<BlockNumber>) -> BoxFuture<RpcU256, Error> {
 		let request = CallRequest::into(request);
-		let signed = self.sign_call(request)?;
+		let signed = match self.sign_call(request) {
+			Ok(signed) => signed,
+			Err(e) => return future::err(e).boxed(),
+		};
 		future::done(take_weakf!(self.client).estimate_gas(&signed, num.0.into())
 			.map(Into::into)
 			.map_err(errors::from_call_error)

rpc/src/v1/impls/light/eth.rs

@@ -24,6 +24,7 @@ use std::sync::Arc;
 use jsonrpc_core::Error;
 use jsonrpc_macros::Trailing;
 
+use light::cache::Cache as LightDataCache;
 use light::client::Client as LightClient;
 use light::{cht, TransactionQueue};
 use light::on_demand::{request, OnDemand};
@@ -31,17 +32,18 @@ use light::on_demand::{request, OnDemand};
 use ethcore::account_provider::{AccountProvider, DappId};
 use ethcore::basic_account::BasicAccount;
 use ethcore::encoded;
+use ethcore::executed::{Executed, ExecutionError};
 use ethcore::ids::BlockId;
-use ethcore::transaction::SignedTransaction;
+use ethcore::transaction::{Action, SignedTransaction, Transaction as EthTransaction};
 use ethsync::LightSync;
 use rlp::{UntrustedRlp, View};
 use util::sha3::{SHA3_NULL_RLP, SHA3_EMPTY_LIST_RLP};
-use util::{RwLock, U256};
+use util::{RwLock, Mutex, FixedHash, Uint, U256};
 
 use futures::{future, Future, BoxFuture, IntoFuture};
 use futures::sync::oneshot;
 
-use v1::helpers::{CallRequest as CRequest, errors, limit_logs};
+use v1::helpers::{CallRequest as CRequest, errors, limit_logs, dispatch};
 use v1::helpers::block_import::is_major_importing;
 use v1::traits::Eth;
 use v1::types::{
@@ -60,6 +62,7 @@ pub struct EthClient {
 	on_demand: Arc<OnDemand>,
 	transaction_queue: Arc<RwLock<TransactionQueue>>,
 	accounts: Arc<AccountProvider>,
+	cache: Arc<Mutex<LightDataCache>>,
 }
 
 // helper for internal error: on demand sender cancelled.
@@ -67,6 +70,8 @@ fn err_premature_cancel(_cancel: oneshot::Canceled) -> Error {
 	errors::internal("on-demand sender prematurely cancelled", "")
 }
 
+type ExecutionResult = Result<Executed, ExecutionError>;
+
 impl EthClient {
 	/// Create a new `EthClient` with a handle to the light sync instance, client,
 	/// and on-demand request service, which is assumed to be attached as a handler.
@@ -76,6 +81,7 @@ impl EthClient {
 		on_demand: Arc<OnDemand>,
 		transaction_queue: Arc<RwLock<TransactionQueue>>,
 		accounts: Arc<AccountProvider>,
+		cache: Arc<Mutex<LightDataCache>>,
 	) -> Self {
 		EthClient {
 			sync: sync,
@@ -83,6 +89,7 @@ impl EthClient {
 			on_demand: on_demand,
 			transaction_queue: transaction_queue,
 			accounts: accounts,
+			cache: cache,
 		}
 	}
 
@@ -149,24 +156,77 @@ impl EthClient {
 	}
 
 	// helper for getting proved execution.
-	fn proved_execution(&self, req: CallRequest, num: Trailing<BlockNumber>) -> Result<Option<ProvedExecution>, Error> {
+	fn proved_execution(&self, req: CallRequest, num: Trailing<BlockNumber>) -> BoxFuture<ExecutionResult, Error> {
-		let (sync, on_demand) = (self.sync.clone(), self.on_demand.clone());
+		const DEFAULT_GAS_PRICE: U256 = U256([0, 0, 0, 21_000_000]);
+
+
+		let (sync, on_demand, client) = (self.sync.clone(), self.on_demand.clone(), self.client.clone());
 		let req: CRequest = req.into();
 		let id = num.0.into();
 
-		let from = request.from.unwrap_or(Address::zero());
+		let from = req.from.unwrap_or(Address::zero());
-		let action = request.to.map_or(Action::Create, Action::Call);
+		let nonce_fut = match req.nonce {
-		let gas: request.gas.unwrap_or(U256::from(10_000_000));
+			Some(nonce) => future::ok(Some(nonce)).boxed(),
-		let value = request.value.unwrap_or_else(U256::zero);
+			None => self.account(from, id).map(|acc| acc.map(|a| a.nonce)).boxed(),
-		let data = request.data.map_or_else(Vec::new, |d| d.to_vec());
+		};
 
-		sync.with_context(|ctx| {
+		let gas_price_fut = match req.gas_price {
-			let nonce_fut = req.nonce.map(Some).ok_or(err_no_context())
+			Some(price) => future::ok(price).boxed(),
-				.or_else(|_| self.account(from, id).map(|acc| acc.map(|a| a.nonce)));
+			None => dispatch::fetch_gas_price_corpus(
+				self.sync.clone(),
+				self.client.clone(),
+				self.on_demand.clone(),
+				self.cache.clone(),
+			).map(|corp| match corp.median() {
+				Some(median) => *median,
+				None => DEFAULT_GAS_PRICE,
+			}).boxed()
+		};
 
-			let gas_price_fut = req.gas_price.map(Some).ok_or(err_no_context())
+		// if nonce resolves, this should too since it'll be in the LRU-cache.
-				.or_else(|_| unimplemented!())
+		let header_fut = self.header(id);
+
+		// fetch missing transaction fields from the network.
+		nonce_fut.join(gas_price_fut).and_then(move |(nonce, gas_price)| {
+			let action = req.to.map_or(Action::Create, Action::Call);
+			let gas = req.gas.unwrap_or(U256::from(10_000_000)); // better gas amount?
+			let value = req.value.unwrap_or_else(U256::zero);
+			let data = req.data.map_or_else(Vec::new, |d| d.to_vec());
+
+			future::done(match nonce {
+				Some(n) => Ok(EthTransaction {
+					nonce: n,
+					action: action,
+					gas: gas,
+					gas_price: gas_price,
+					value: value,
+					data: data,
+				}.fake_sign(from)),
+				None => Err(errors::unknown_block()),
 			})
+		}).join(header_fut).and_then(move |(tx, hdr)| {
+			// then request proved execution.
+			// TODO: get last-hashes from network.
+			let (env_info, hdr) = match (client.env_info(id), hdr) {
+				(Some(env_info), Some(hdr)) => (env_info, hdr),
+				_ => return future::err(errors::unknown_block()).boxed(),
+			};
+			let request = request::TransactionProof {
+				tx: tx,
+				header: hdr,
+				env_info: env_info,
+				engine: client.engine().clone(),
+			};
+
+			let proved_future = sync.with_context(move |ctx| {
+				on_demand.transaction_proof(ctx, request).map_err(err_premature_cancel).boxed()
+			});
+
+			match proved_future {
+				Some(fut) => fut.boxed(),
+				None => future::err(errors::network_disabled()).boxed(),
+			}
+		}).boxed()
 	}
 }
 
@@ -344,10 +404,9 @@ impl Eth for EthClient {
 	}
 
 	fn call(&self, req: CallRequest, num: Trailing<BlockNumber>) -> BoxFuture<Bytes, Error> {
-		self.proved_execution().and_then(|res| {
+		self.proved_execution(req, num).and_then(|res| {
 			match res {
-				Ok(Some(exec)) => Ok(exec.output.into()),
+				Ok(exec) => Ok(exec.output.into()),
-				Ok(None) => Err(errors::unknown_block()),
 				Err(e) => Err(errors::execution(e)),
 			}
 		}).boxed()
@@ -355,10 +414,9 @@ impl Eth for EthClient {
 
 	fn estimate_gas(&self, req: CallRequest, num: Trailing<BlockNumber>) -> BoxFuture<RpcU256, Error> {
 		// TODO: binary chop for more accurate estimates.
-		self.proved_execution().and_then(|res| {
+		self.proved_execution(req, num).and_then(|res| {
 			match res {
-				Ok(Some(exec)) => Ok((exec.refunded + exec.gas_used).into()),
+				Ok(exec) => Ok((exec.refunded + exec.gas_used).into()),
-				Ok(None) => Err(errors::unknown_block()),
 				Err(e) => Err(errors::execution(e)),
 			}
 		}).boxed()