support for rpc polling

ethcore/src/client.rs

@@ -123,6 +123,9 @@ pub trait BlockChainClient : Sync + Send {
 	/// Get block total difficulty.
 	fn block_total_difficulty(&self, id: BlockId) -> Option<U256>;
 
+	/// Get block hash.
+	fn block_hash(&self, id: BlockId) -> Option<H256>;
+
 	/// Get address code.
 	fn code(&self, address: &Address) -> Option<Bytes>;
 
@@ -533,6 +536,11 @@ impl BlockChainClient for Client {
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_details(&hash)).map(|d| d.total_difficulty)
 	}
 
+	fn block_hash(&self, id: BlockId) -> Option<H256> {
+		let chain = self.chain.read().unwrap();
+		Self::block_hash(&chain, id)
+	}
+
 	fn code(&self, address: &Address) -> Option<Bytes> {
 		self.state().code(address)
 	}

ethcore/src/filter.rs

@@ -42,6 +42,22 @@ pub struct Filter {
 	pub topics: [Option<Vec<H256>>; 4],
 }
 
+impl Clone for Filter {
+	fn clone(&self) -> Self {
+		let mut topics = [None, None, None, None];
+		for i in 0..4 {
+			topics[i] = self.topics[i].clone();
+		}
+
+		Filter {
+			from_block: self.from_block.clone(),
+			to_block: self.to_block.clone(),
+			address: self.address.clone(),
+			topics: topics
+		}
+	}
+}
+
 impl Filter {
 	/// Returns combinations of each address and topic.	
 	pub fn bloom_possibilities(&self) -> Vec<H2048> {

rpc/Cargo.toml

@@ -20,6 +20,7 @@ ethash = { path = "../ethash" }
 ethsync = { path = "../sync" }
 clippy = { version = "0.0.44", optional = true }
 rustc-serialize = "0.3"
+transient-hashmap = "0.1"
 serde_macros = { version = "0.7.0", optional = true }
 
 [build-dependencies]

rpc/src/lib.rs

@@ -27,6 +27,7 @@ extern crate jsonrpc_http_server;
 extern crate ethcore_util as util;
 extern crate ethcore;
 extern crate ethsync;
+extern crate transient_hashmap;
 
 #[cfg(feature = "serde_macros")]
 include!("lib.rs.in");

rpc/src/v1/helpers/mod.rs

@@ -0,0 +1,21 @@
+// Copyright 2015, 2016 Ethcore (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/>.
+
+mod poll_manager;
+mod poll_filter;
+
+pub use self::poll_manager::PollManager;
+pub use self::poll_filter::PollFilter;

rpc/src/v1/helpers/poll_filter.rs

@@ -0,0 +1,10 @@
+//! Helper type with all filter possibilities.
+
+use ethcore::filter::Filter;
+
+#[derive(Clone)]
+pub enum PollFilter {
+	Block,
+	PendingTransaction,
+	Logs(Filter)
+}

rpc/src/v1/helpers/poll_manager.rs

@@ -0,0 +1,144 @@
+// Copyright 2015, 2016 Ethcore (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/>.
+
+//! Indexes all rpc poll requests.
+
+use transient_hashmap::{TransientHashMap, Timer, StandardTimer};
+
+/// Lifetime of poll (in seconds).
+const POLL_LIFETIME: u64 = 60;
+
+pub type PollId = usize;
+pub type BlockNumber = u64;
+
+pub struct PollInfo<F> {
+	pub filter: F,
+	pub block_number: BlockNumber
+}
+
+impl<F> Clone for PollInfo<F> where F: Clone {
+	fn clone(&self) -> Self {
+		PollInfo {
+			filter: self.filter.clone(),
+			block_number: self.block_number.clone()
+		}
+	}
+}
+
+/// Indexes all poll requests.
+///
+/// Lazily garbage collects unused polls info.
+pub struct PollManager<F, T = StandardTimer> where T: Timer {
+	polls: TransientHashMap<PollId, PollInfo<F>, T>,
+	next_available_id: PollId
+}
+
+impl<F> PollManager<F, StandardTimer> {
+	/// Creates new instance of indexer.
+	pub fn new() -> Self {
+		PollManager::new_with_timer(Default::default())
+	}
+}
+
+impl<F, T> PollManager<F, T> where T: Timer {
+	pub fn new_with_timer(timer: T) -> Self {
+		PollManager {
+			polls: TransientHashMap::new_with_timer(POLL_LIFETIME, timer),
+			next_available_id: 0,
+		}
+	}
+
+	/// Returns id which can be used for new poll.
+	///
+	/// Stores information when last poll happend.
+	pub fn create_poll(&mut self, filter: F, block: BlockNumber) -> PollId {
+		self.polls.prune();
+		let id = self.next_available_id;
+		self.next_available_id += 1;
+		self.polls.insert(id, PollInfo {
+			filter: filter,
+			block_number: block,
+		});
+		id
+	}
+
+	/// Updates information when last poll happend.
+	pub fn update_poll(&mut self, id: &PollId, block: BlockNumber) {
+		self.polls.prune();
+		if let Some(info) = self.polls.get_mut(id) {
+			info.block_number = block;
+		}
+	}
+
+	/// Returns number of block when last poll happend.
+	pub fn get_poll_info(&mut self, id: &PollId) -> Option<&PollInfo<F>> {
+		self.polls.prune();
+		self.polls.get(id)
+	}
+
+	/// Removes poll info.
+	pub fn remove_poll(&mut self, id: &PollId) {
+		self.polls.remove(id);
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use std::cell::RefCell;
+	use transient_hashmap::Timer;
+	use v1::helpers::PollManager;
+
+	struct TestTimer<'a> {
+		time: &'a RefCell<i64>,
+	}
+
+	impl<'a> Timer for TestTimer<'a> {
+		fn get_time(&self) -> i64 {
+			*self.time.borrow()
+		}
+	}
+
+	#[test]
+	fn test_poll_indexer() {
+		let time = RefCell::new(0);
+		let timer = TestTimer {
+			time: &time,
+		};
+
+		let mut indexer = PollManager::new_with_timer(timer);
+		assert_eq!(indexer.create_poll(false, 20), 0);
+		assert_eq!(indexer.create_poll(true, 20), 1);
+
+		*time.borrow_mut() = 10;
+		indexer.update_poll(&0, 21);
+		assert_eq!(indexer.get_poll_info(&0).unwrap().filter, false);
+		assert_eq!(indexer.get_poll_info(&0).unwrap().block_number, 21);
+
+		*time.borrow_mut() = 30;
+		indexer.update_poll(&1, 23);
+		assert_eq!(indexer.get_poll_info(&1).unwrap().filter, true);
+		assert_eq!(indexer.get_poll_info(&1).unwrap().block_number, 23);
+
+		*time.borrow_mut() = 75;
+		indexer.update_poll(&0, 30);
+		assert!(indexer.get_poll_info(&0).is_none());
+		assert_eq!(indexer.get_poll_info(&1).unwrap().filter, true);
+		assert_eq!(indexer.get_poll_info(&1).unwrap().block_number, 23);
+
+		indexer.remove_poll(&1);
+		assert!(indexer.get_poll_info(&1).is_none());
+	}
+}

rpc/src/v1/impls/eth.rs

@@ -15,11 +15,12 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 //! Eth rpc implementation.
+use std::collections::HashMap;
+use std::sync::{Arc, Weak, Mutex, RwLock};
 use ethsync::{EthSync, SyncState};
 use jsonrpc_core::*;
 use util::numbers::*;
 use util::sha3::*;
-use util::standard::{RwLock, HashMap, Arc, Weak};
 use util::rlp::encode;
 use ethcore::client::*;
 use ethcore::block::{IsBlock};
@@ -29,6 +30,7 @@ use ethcore::ethereum::Ethash;
 use ethcore::ethereum::denominations::shannon;
 use v1::traits::{Eth, EthFilter};
 use v1::types::{Block, BlockTransactions, BlockNumber, Bytes, SyncStatus, SyncInfo, Transaction, OptionalValue, Index, Filter, Log};
+use v1::helpers::{PollFilter, PollManager};
 
 /// Eth rpc implementation.
 pub struct EthClient {
@@ -255,28 +257,98 @@ impl Eth for EthClient {
 
 /// Eth filter rpc implementation.
 pub struct EthFilterClient {
-	client: Weak<Client>
+	client: Weak<Client>,
+	polls: Mutex<PollManager<PollFilter>>,
 }
 
 impl EthFilterClient {
 	/// Creates new Eth filter client.
 	pub fn new(client: &Arc<Client>) -> Self {
 		EthFilterClient {
-			client: Arc::downgrade(client)
+			client: Arc::downgrade(client),
+			polls: Mutex::new(PollManager::new())
 		}
 	}
 }
 
 impl EthFilter for EthFilterClient {
-	fn new_block_filter(&self, _params: Params) -> Result<Value, Error> {
-		Ok(Value::U64(0))
+	fn new_filter(&self, params: Params) -> Result<Value, Error> {
+		from_params::<(Filter,)>(params)
+			.and_then(|(filter,)| {
+				let mut polls = self.polls.lock().unwrap();
+				let id = polls.create_poll(PollFilter::Logs(filter.into()), take_weak!(self.client).chain_info().best_block_number);
+				to_value(&U256::from(id))
+			})
 	}
 
-	fn new_pending_transaction_filter(&self, _params: Params) -> Result<Value, Error> {
-		Ok(Value::U64(1))
+	fn new_block_filter(&self, params: Params) -> Result<Value, Error> {
+		match params {
+			Params::None => {
+				let mut polls = self.polls.lock().unwrap();
+				let id = polls.create_poll(PollFilter::Block, take_weak!(self.client).chain_info().best_block_number);
+				to_value(&U256::from(id))
+			},
+			_ => Err(Error::invalid_params())
+		}
 	}
 
-	fn filter_changes(&self, _: Params) -> Result<Value, Error> {
-		to_value(&take_weak!(self.client).chain_info().best_block_hash).map(|v| Value::Array(vec![v]))
+	fn new_pending_transaction_filter(&self, params: Params) -> Result<Value, Error> {
+		match params {
+			Params::None => {
+				let mut polls = self.polls.lock().unwrap();
+				let id = polls.create_poll(PollFilter::PendingTransaction, take_weak!(self.client).chain_info().best_block_number);
+				to_value(&U256::from(id))
+			},
+			_ => Err(Error::invalid_params())
+		}
+	}
+
+	fn filter_changes(&self, params: Params) -> Result<Value, Error> {
+		let client = take_weak!(self.client);
+		from_params::<(Index,)>(params)
+			.and_then(|(index,)| {
+				let info = self.polls.lock().unwrap().get_poll_info(&index.value()).cloned();
+				match info {
+					None => Ok(Value::Array(vec![] as Vec<Value>)),
+					Some(info) => match info.filter {
+						PollFilter::Block => {
+							let current_number = client.chain_info().best_block_number;
+							let hashes = (info.block_number..current_number).into_iter()
+								.map(BlockId::Number)
+								.filter_map(|id| client.block_hash(id))
+								.collect::<Vec<H256>>();
+
+							self.polls.lock().unwrap().update_poll(&index.value(), current_number);
+
+							to_value(&hashes)
+						},
+						PollFilter::PendingTransaction => {
+							// TODO: fix implementation once TransactionQueue is merged
+							to_value(&vec![] as &Vec<H256>)
+						},
+						PollFilter::Logs(mut filter) => {
+							filter.from_block = BlockId::Number(info.block_number);
+							filter.to_block = BlockId::Latest;
+							let logs = client.logs(filter)
+								.into_iter()
+								.map(From::from)
+								.collect::<Vec<Log>>();
+
+							let current_number = client.chain_info().best_block_number;
+							self.polls.lock().unwrap().update_poll(&index.value(), current_number);
+
+							to_value(&logs)
+						}
+					}
+				}
+			})
+	}
+
+	fn uninstall_filter(&self, params: Params) -> Result<Value, Error> {
+		from_params::<(Index,)>(params)
+			.and_then(|(index,)| {
+				self.polls.lock().unwrap().remove_poll(&index.value());
+				to_value(&true)
+			})
 	}
 }

rpc/src/v1/mod.rs

@@ -23,6 +23,7 @@ mod impls;
 mod types;
 #[cfg(test)]
 mod tests;
+mod helpers;
 
 pub use self::traits::{Web3, Eth, EthFilter, Net};
 pub use self::impls::*;