Merge pull request #5833 from paritytech/pubsub-docs

Docs for Pub-Sub, optional parameter for parity_subscribe

Cargo.lock

@@ -1048,7 +1048,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "jsonrpc-core"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1060,7 +1060,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-http-server"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "hyper 0.10.0-a.0 (git+https://github.com/paritytech/hyper)",
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -1073,7 +1073,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-ipc-server"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "bytes 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -1086,7 +1086,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-macros"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
  "jsonrpc-pubsub 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -1096,7 +1096,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-minihttp-server"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
  "jsonrpc-server-utils 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -1110,7 +1110,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-pubsub"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1120,7 +1120,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-server-utils"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "globset 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -1132,7 +1132,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-tcp-server"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "bytes 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
@@ -1146,7 +1146,7 @@ dependencies = [
 [[package]]
 name = "jsonrpc-ws-server"
 version = "7.0.0"
-source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#87db29043826f152cce171351fa34fada287764d"
+source = "git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7#d8dae528860d7fe976a8e3ec060a792e2496573b"
 dependencies = [
  "jsonrpc-core 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",
  "jsonrpc-server-utils 7.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.7)",

js/src/api/api.spec.js

@@ -36,12 +36,19 @@ describe('api/Api', () => {
 
   describe('interface', () => {
     const api = new Api(new Api.Transport.Http(TEST_HTTP_URL, -1));
+    const ignored = [
+      'eth_subscribe', 'eth_unsubscribe',
+      'parity_subscribe', 'parity_unsubscribe',
+      'signer_subscribePending', 'signer_unsubscribePending'
+    ];
 
     Object.keys(ethereumRpc).sort().forEach((endpoint) => {
       describe(endpoint, () => {
-        Object.keys(ethereumRpc[endpoint]).sort().forEach((method) => {
-          endpointTest(api, endpoint, method);
-        });
+        Object.keys(ethereumRpc[endpoint]).sort()
+          .filter(method => ignored.indexOf(method) !== -1)
+          .forEach((method) => {
+            endpointTest(api, endpoint, method);
+          });
       });
     });
   });

js/src/jsonrpc/interfaces/eth.js

@@ -17,6 +17,8 @@
 import { Address, BlockNumber, Data, Hash, Quantity, CallRequest, TransactionRequest } from '../types';
 import { withPreamble, fromDecimal, withComment, Dummy } from '../helpers';
 
+const SUBDOC_PUBSUB = 'pubsub';
+
 export default withPreamble(`
 
 ## The default block parameter
@@ -1192,5 +1194,60 @@ The following options are possible for the \`defaultBlock\` parameter:
       type: Boolean,
       desc: 'whether the call was successful'
     }
+  },
+
+  // Pub-Sub
+  subscribe: {
+    subdoc: SUBDOC_PUBSUB,
+    desc: `
+Starts a subscription (on WebSockets / IPC / TCP transports) to a particular event. For every event that
+matches the subscription a JSON-RPC notification with event details and subscription ID will be sent to a client.
+
+An example notification received by subscribing to \`newHeads\` event:
+\`\`\`
+{"jsonrpc":"2.0","method":"eth_subscription","params":{"subscription":"0x416d77337e24399d","result":{"difficulty":"0xd9263f42a87",<...>,
+"uncles":[]}}}
+\`\`\`
+
+You can unsubscribe using \`eth_unsubscribe\` RPC method. Subscriptions are also tied to a transport
+connection, disconnecting causes all subscriptions to be canceled.
+    `,
+    params: [
+      {
+        type: String,
+        desc: 'Subscription type: one of `newHeads`, `logs`',
+        example: 'newHeads'
+      },
+      {
+        type: Object,
+        desc: `
+Subscription type-specific parameters. It must be left empty for
+\`newHeads\` and must contain filter object for \`logs\`.
+        `,
+        example: {
+          fromBlock: 'latest',
+          toBlock: 'latest'
+        }
+      }
+    ],
+    returns: {
+      type: String,
+      desc: 'Assigned subscription ID',
+      example: '0x416d77337e24399d'
+    }
+  },
+  unsubscribe: {
+    subdoc: SUBDOC_PUBSUB,
+    desc: 'Unsubscribes from a subscription.',
+    params: [{
+      type: String,
+      desc: 'Subscription ID',
+      example: '0x416d77337e24399d'
+    }],
+    returns: {
+      type: Boolean,
+      desc: 'whether the call was successful',
+      example: true
+    }
   }
 });

js/src/jsonrpc/interfaces/parity.js

@@ -26,6 +26,7 @@ const SECTION_VAULT = 'Account Vaults';
 
 const SUBDOC_SET = 'set';
 const SUBDOC_ACCOUNTS = 'accounts';
+const SUBDOC_PUBSUB = 'pubsub';
 
 export default {
   accountsInfo: {
@@ -2005,6 +2006,54 @@ export default {
       desc: 'Base58 encoded CID',
       example: 'QmSbFjqjd6nFwNHqsBCC7SK8GShGcayLUEtysJjNGhZAnC'
     }
+  },
+
+  // Pub-Sub
+  subscribe: {
+    subdoc: SUBDOC_PUBSUB,
+    desc: `
+Starts a subscription (on WebSockets / IPC / TCP transports) to results of calling some other RPC method.
+For every change in returned value of that RPC call a JSON-RPC notification with result and subscription ID will be sent to a client.
+
+An example notification received by subscribing to \`eth_accounts\` RPC method:
+\`\`\`
+{"jsonrpc":"2.0","method":"parity_subscription","params":{"subscription":"0x416d77337e24399d","result":["0xcd2a3d9f938e13cd947ec05abc7fe734df8dd826"]}}
+\`\`\`
+
+You can unsubscribe using \`parity_unsubscribe\` RPC method. Subscriptions are also tied to a transport
+connection, disconnecting causes all subscriptions to be canceled.
+    `,
+    params: [
+      {
+        type: String,
+        desc: 'RPC method name',
+        example: 'eth_getBalance'
+      },
+      {
+        type: Array,
+        desc: 'Parameters passed to RPC method. (Optional, defaults to no parameters)',
+        example: ['0xcd2a3d9f938e13cd947ec05abc7fe734df8dd826', 'latest']
+      }
+    ],
+    returns: {
+      type: String,
+      desc: 'Assigned subscription ID',
+      example: '0x416d77337e24399d'
+    }
+  },
+  unsubscribe: {
+    subdoc: SUBDOC_PUBSUB,
+    desc: 'Unsubscribes from a subscription.',
+    params: [{
+      type: String,
+      desc: 'Subscription ID',
+      example: '0x416d77337e24399d'
+    }],
+    returns: {
+      type: Boolean,
+      desc: 'whether the call was successful',
+      example: true
+    }
   }
 
 };

js/src/jsonrpc/interfaces/signer.js

@@ -198,5 +198,40 @@ export default {
       desc: '`true` when enabled, `false` when disabled.',
       example: true
     }
+  },
+
+  // Pub-Sub
+  subscribePending: {
+    desc: `
+Starts a subscription for transactions in the confirmation queue.
+Each event contains all transactions currently in the queue.
+
+An example notification received by subscribing to this event:
+\`\`\`
+{"jsonrpc":"2.0","method":"signer_pending","params":{"subscription":"0x416d77337e24399d","result":[]}}
+\`\`\`
+
+You can unsubscribe using \`signer_unsubscribePending\` RPC method. Subscriptions are also tied to a transport
+connection, disconnecting causes all subscriptions to be canceled.
+    `,
+    params: [],
+    returns: {
+      type: String,
+      desc: 'Assigned subscription ID',
+      example: '0x416d77337e24399d'
+    }
+  },
+  unsubscribePending: {
+    desc: 'Unsubscribes from pending transactions subscription.',
+    params: [{
+      type: String,
+      desc: 'Subscription ID',
+      example: '0x416d77337e24399d'
+    }],
+    returns: {
+      type: Boolean,
+      desc: 'whether the call was successful',
+      example: true
+    }
   }
 };

rpc/src/v1/helpers/light_fetch.rs

@@ -162,7 +162,7 @@ impl LightFetch {
 
 		let (sync, on_demand, client) = (self.sync.clone(), self.on_demand.clone(), self.client.clone());
 		let req: CallRequestHelper = req.into();
-		let id = num.0.into();
+		let id = num.unwrap_or_default().into();
 
 		let from = req.from.unwrap_or(Address::zero());
 		let nonce_fut = match req.nonce {

rpc/src/v1/impls/eth.rs

@@ -361,7 +361,7 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 	fn balance(&self, address: RpcH160, num: Trailing<BlockNumber>) -> BoxFuture<RpcU256, Error> {
 		let address = address.into();
 
-		let res = match num.0.clone() {
+		let res = match num.unwrap_or_default() {
 			BlockNumber::Pending => {
 				match self.miner.balance(&*self.client, &address) {
 					Some(balance) => Ok(balance.into()),
@@ -384,7 +384,7 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 		let address: Address = RpcH160::into(address);
 		let position: U256 = RpcU256::into(pos);
 
-		let res = match num.0.clone() {
+		let res = match num.unwrap_or_default() {
 			BlockNumber::Pending => {
 				match self.miner.storage_at(&*self.client, &address, &H256::from(position)) {
 					Some(s) => Ok(s.into()),
@@ -406,7 +406,7 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 	fn transaction_count(&self, address: RpcH160, num: Trailing<BlockNumber>) -> BoxFuture<RpcU256, Error> {
 		let address: Address = RpcH160::into(address);
 
-		let res = match num.0.clone() {
+		let res = match num.unwrap_or_default() {
 			BlockNumber::Pending if self.options.pending_nonce_from_queue => {
 				let nonce = self.miner.last_nonce(&address)
 					.map(|n| n + 1.into())
@@ -468,7 +468,7 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 	fn code_at(&self, address: RpcH160, num: Trailing<BlockNumber>) -> BoxFuture<Bytes, Error> {
 		let address: Address = RpcH160::into(address);
 
-		let res = match num.0.clone() {
+		let res = match num.unwrap_or_default() {
 			BlockNumber::Pending => {
 				match self.miner.code(&*self.client, &address) {
 					Some(code) => Ok(code.map_or_else(Bytes::default, Bytes::new)),
@@ -553,7 +553,7 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 	}
 
 	fn work(&self, no_new_work_timeout: Trailing<u64>) -> Result<Work, Error> {
-		let no_new_work_timeout = no_new_work_timeout.0;
+		let no_new_work_timeout = no_new_work_timeout.unwrap_or_default();
 
 		// check if we're still syncing and return empty strings in that case
 		{
@@ -638,7 +638,7 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 			Err(e) => return future::err(e).boxed(),
 		};
 
-		let result = match num.0 {
+		let result = match num.unwrap_or_default() {
 			BlockNumber::Pending => self.miner.call(&*self.client, &signed, Default::default()),
 			num => self.client.call(&signed, num.into(), Default::default()),
 		};
@@ -655,7 +655,7 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM> Eth for EthClient<C, SN, S, M, EM> where
 			Ok(signed) => signed,
 			Err(e) => return future::err(e).boxed(),
 		};
-		future::done(self.client.estimate_gas(&signed, num.0.into())
+		future::done(self.client.estimate_gas(&signed, num.unwrap_or_default().into())
 			.map(Into::into)
 			.map_err(errors::from_call_error)
 		).boxed()

rpc/src/v1/impls/eth_pubsub.rs

@@ -144,8 +144,9 @@ impl<C: Send + Sync + 'static> EthPubSub for EthPubSubClient<C> {
 		kind: pubsub::Kind,
 		params: Trailing<pubsub::Params>,
 	) {
-		match (kind, params.0) {
-			(pubsub::Kind::NewHeads, pubsub::Params::None) => {
+		let params: Option<pubsub::Params> = params.into();
+		match (kind, params) {
+			(pubsub::Kind::NewHeads, None) => {
 				self.heads_subscribers.lock().push(subscriber)
 			},
 			_ => {

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

@@ -270,7 +270,7 @@ impl Eth for EthClient {
 	}
 
 	fn balance(&self, address: RpcH160, num: Trailing<BlockNumber>) -> BoxFuture<RpcU256, Error> {
-		self.fetcher().account(address.into(), num.0.into())
+		self.fetcher().account(address.into(), num.unwrap_or_default().into())
 			.map(|acc| acc.map_or(0.into(), |a| a.balance).into()).boxed()
 	}
 
@@ -287,7 +287,7 @@ impl Eth for EthClient {
 	}
 
 	fn transaction_count(&self, address: RpcH160, num: Trailing<BlockNumber>) -> BoxFuture<RpcU256, Error> {
-		self.fetcher().account(address.into(), num.0.into())
+		self.fetcher().account(address.into(), num.unwrap_or_default().into())
 			.map(|acc| acc.map_or(0.into(), |a| a.nonce).into()).boxed()
 	}
 

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

@@ -98,7 +98,7 @@ impl Parity for ParityClient {
 	type Metadata = Metadata;
 
 	fn accounts_info(&self, dapp: Trailing<DappId>) -> Result<BTreeMap<H160, AccountInfo>, Error> {
-		let dapp = dapp.0;
+		let dapp = dapp.unwrap_or_default();
 
 		let store = &self.accounts;
 		let dapp_accounts = store
@@ -383,7 +383,7 @@ impl Parity for ParityClient {
 			}
 		};
 
-		self.fetcher().header(number.0.into()).map(from_encoded).boxed()
+		self.fetcher().header(number.unwrap_or_default().into()).map(from_encoded).boxed()
 	}
 
 	fn ipfs_cid(&self, content: Bytes) -> Result<String, Error> {

rpc/src/v1/impls/parity.rs

@@ -124,7 +124,7 @@ impl<C, M, S: ?Sized, U> Parity for ParityClient<C, M, S, U> where
 	type Metadata = Metadata;
 
 	fn accounts_info(&self, dapp: Trailing<DappId>) -> Result<BTreeMap<H160, AccountInfo>, Error> {
-		let dapp = dapp.0;
+		let dapp = dapp.unwrap_or_default();
 
 		let store = self.account_provider()?;
 		let dapp_accounts = store
@@ -272,13 +272,13 @@ impl<C, M, S: ?Sized, U> Parity for ParityClient<C, M, S, U> where
 
 	fn list_accounts(&self, count: u64, after: Option<H160>, block_number: Trailing<BlockNumber>) -> Result<Option<Vec<H160>>, Error> {
 		Ok(self.client
-			.list_accounts(block_number.0.into(), after.map(Into::into).as_ref(), count)
+			.list_accounts(block_number.unwrap_or_default().into(), after.map(Into::into).as_ref(), count)
 			.map(|a| a.into_iter().map(Into::into).collect()))
 	}
 
 	fn list_storage_keys(&self, address: H160, count: u64, after: Option<H256>, block_number: Trailing<BlockNumber>) -> Result<Option<Vec<H256>>, Error> {
 		Ok(self.client
-			.list_storage(block_number.0.into(), &address.into(), after.map(Into::into).as_ref(), count)
+			.list_storage(block_number.unwrap_or_default().into(), &address.into(), after.map(Into::into).as_ref(), count)
 			.map(|a| a.into_iter().map(Into::into).collect()))
 	}
 
@@ -394,7 +394,7 @@ impl<C, M, S: ?Sized, U> Parity for ParityClient<C, M, S, U> where
 	fn block_header(&self, number: Trailing<BlockNumber>) -> BoxFuture<RichHeader, Error> {
 		const EXTRA_INFO_PROOF: &'static str = "Object exists in in blockchain (fetched earlier), extra_info is always available if object exists; qed";
 
-		let id: BlockId = number.0.into();
+		let id: BlockId = number.unwrap_or_default().into();
 		let encoded = match self.client.block_header(id.clone()) {
 			Some(encoded) => encoded,
 			None => return future::err(errors::unknown_block()).boxed(),

rpc/src/v1/impls/pubsub.rs

@@ -22,6 +22,7 @@ use util::RwLock;
 
 use futures::{self, BoxFuture, Future, Stream, Sink};
 use jsonrpc_core::{self as core, Error, MetaIoHandler};
+use jsonrpc_macros::Trailing;
 use jsonrpc_macros::pubsub::Subscriber;
 use jsonrpc_pubsub::SubscriptionId;
 use tokio_timer;
@@ -74,7 +75,8 @@ impl PubSubClient<core::NoopMiddleware> {
 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) {
+	fn parity_subscribe(&self, mut meta: Metadata, subscriber: Subscriber<core::Value>, method: String, params: Trailing<core::Params>) {
+		let params = params.unwrap_or(core::Params::Array(vec![]));
 		// Make sure to get rid of PubSub session otherwise it will never be dropped.
 		meta.session = None;
 

rpc/src/v1/impls/traces.rs

@@ -80,7 +80,7 @@ impl<C, M> Traces for TracesClient<C, M> where C: MiningBlockChainClient + 'stat
 	}
 
 	fn call(&self, request: CallRequest, flags: Vec<String>, block: Trailing<BlockNumber>) -> Result<TraceResults, Error> {
-		let block = block.0;
+		let block = block.unwrap_or_default();
 
 		let request = CallRequest::into(request);
 		let signed = fake_sign::sign_call(&self.client, &self.miner, request)?;
@@ -91,7 +91,7 @@ impl<C, M> Traces for TracesClient<C, M> where C: MiningBlockChainClient + 'stat
 	}
 
 	fn raw_transaction(&self, raw_transaction: Bytes, flags: Vec<String>, block: Trailing<BlockNumber>) -> Result<TraceResults, Error> {
-		let block = block.0;
+		let block = block.unwrap_or_default();
 
 		let tx = UntrustedRlp::new(&raw_transaction.into_vec()).as_val().map_err(|e| errors::invalid_params("Transaction is not valid RLP", e))?;
 		let signed = SignedTransaction::new(tx).map_err(errors::from_transaction_error)?;

rpc/src/v1/traits/pubsub.rs

@@ -18,6 +18,7 @@
 
 use jsonrpc_core::{Error, Value, Params};
 use jsonrpc_pubsub::SubscriptionId;
+use jsonrpc_macros::Trailing;
 use jsonrpc_macros::pubsub::Subscriber;
 use futures::BoxFuture;
 
@@ -29,7 +30,7 @@ build_rpc_trait! {
 		#[pubsub(name = "parity_subscription")] {
 			/// Subscribe to changes of any RPC method in Parity.
 			#[rpc(name = "parity_subscribe")]
-			fn parity_subscribe(&self, Self::Metadata, Subscriber<Value>, String, Params);
+			fn parity_subscribe(&self, Self::Metadata, Subscriber<Value>, String, Trailing<Params>);
 
 			/// Unsubscribe from existing Parity subscription.
 			#[rpc(name = "parity_unsubscribe")]