Generic PubSub implementation (#5456)

* Generic PubSub

* Adding more tests.

* Fix submodules.

* Remove PartialEq

* Actually remove the implementation.

* Update mod.rs

* Update mod.rs

rpc/src/v1/impls/mod.rs

@@ -23,6 +23,7 @@ mod parity;
 mod parity_accounts;
 mod parity_set;
 mod personal;
+mod pubsub;
 mod signer;
 mod signing;
 mod signing_unsafe;
@@ -33,7 +34,6 @@ mod web3;
 
 pub mod light;
 
-pub use self::web3::Web3Client;
 pub use self::eth::{EthClient, EthClientOptions};
 pub use self::eth_filter::EthFilterClient;
 pub use self::net::NetClient;
@@ -41,9 +41,11 @@ pub use self::parity::ParityClient;
 pub use self::parity_accounts::ParityAccountsClient;
 pub use self::parity_set::ParitySetClient;
 pub use self::personal::PersonalClient;
+pub use self::pubsub::PubSubClient;
 pub use self::signer::SignerClient;
 pub use self::signing::SigningQueueClient;
 pub use self::signing_unsafe::SigningUnsafeClient;
 pub use self::traces::TracesClient;
+pub use self::web3::Web3Client;
 pub use self::rpc::RpcClient;
 pub use self::secretstore::SecretStoreClient;

rpc/src/v1/impls/pubsub.rs

@@ -0,0 +1,100 @@
+// 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/>.
+
+//! Parity-specific PUB-SUB rpc implementation.
+
+use std::sync::Arc;
+use std::time::Duration;
+use util::RwLock;
+
+use futures::{self, BoxFuture, Future, Stream, Sink};
+use jsonrpc_core::{self as core, Error, MetaIoHandler};
+use jsonrpc_macros::pubsub::Subscriber;
+use jsonrpc_pubsub::SubscriptionId;
+use tokio_timer;
+
+use parity_reactor::Remote;
+use v1::helpers::GenericPollManager;
+use v1::metadata::Metadata;
+use v1::traits::PubSub;
+
+/// Parity PubSub implementation.
+pub struct PubSubClient<S: core::Middleware<Metadata>> {
+	poll_manager: Arc<RwLock<GenericPollManager<S>>>,
+	remote: Remote,
+}
+
+impl<S: core::Middleware<Metadata>> PubSubClient<S> {
+	/// Creates new `PubSubClient`.
+	pub fn new(rpc: MetaIoHandler<Metadata, S>, remote: Remote) -> Self {
+		let poll_manager = Arc::new(RwLock::new(GenericPollManager::new(rpc)));
+		let pm2 = poll_manager.clone();
+
+		let timer = tokio_timer::wheel()
+			.tick_duration(Duration::from_millis(500))
+			.build();
+
+		// Start ticking
+		let interval = timer.interval(Duration::from_millis(1000));
+		remote.spawn(interval
+			.map_err(|e| warn!("Polling timer error: {:?}", e))
+			.for_each(move |_| pm2.read().tick())
+		);
+
+		PubSubClient {
+			poll_manager: poll_manager,
+			remote: remote,
+		}
+	}
+}
+
+impl<S: core::Middleware<Metadata>> PubSub for PubSubClient<S> {
+	type Metadata = Metadata;
+
+	fn parity_subscribe(&self, mut meta: Metadata, subscriber: Subscriber<core::Value>, method: String, params: core::Params) {
+		// Make sure to get rid of PubSub session otherwise it will never be dropped.
+		meta.session = None;
+
+		let mut poll_manager = self.poll_manager.write();
+		let (id, receiver) = poll_manager.subscribe(meta, method, params);
+		match subscriber.assign_id(SubscriptionId::Number(id as u64)) {
+			Ok(sink) => {
+				self.remote.spawn(receiver.map(|res| match res {
+					Ok(val) => val,
+					Err(error) => {
+						warn!(target: "pubsub", "Subscription error: {:?}", error);
+						core::Value::Null
+					},
+				}).forward(sink.sink_map_err(|e| {
+					warn!("Cannot send notification: {:?}", e);
+				})).map(|_| ()));
+			},
+			Err(_) => {
+				poll_manager.unsubscribe(id);
+			},
+		}
+	}
+
+	fn parity_unsubscribe(&self, id: SubscriptionId) -> BoxFuture<bool, Error> {
+		let res = if let SubscriptionId::Number(id) = id {
+			self.poll_manager.write().unsubscribe(id as usize)
+		} else {
+			false
+		};
+
+		futures::future::ok(res).boxed()
+	}
+}