Extract RPC definitions from RPC crate. (#3502)

* Extract author API from the substrate-rpc crate.

* Split out API from RPC.

* Clean up naming.

* Fix tests.

* Shorten error translations.

* Update Cargo.lock

substrate/Cargo.lock

@@ -4972,31 +4972,48 @@ name = "substrate-rpc"
 version = "2.0.0"
 dependencies = [
  "assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "derive_more 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-pubsub 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sr-io 2.0.0",
+ "sr-primitives 2.0.0",
+ "sr-version 2.0.0",
+ "substrate-client 2.0.0",
+ "substrate-executor 2.0.0",
+ "substrate-keystore 2.0.0",
+ "substrate-network 2.0.0",
+ "substrate-primitives 2.0.0",
+ "substrate-rpc-api 2.0.0",
+ "substrate-session 2.0.0",
+ "substrate-state-machine 2.0.0",
+ "substrate-test-runtime-client 2.0.0",
+ "substrate-transaction-pool 2.0.0",
+ "tokio 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "substrate-rpc-api"
+version = "2.0.0"
+dependencies = [
+ "derive_more 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core-client 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-derive 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-pubsub 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
- "sr-io 2.0.0",
- "sr-primitives 2.0.0",
  "sr-version 2.0.0",
- "substrate-client 2.0.0",
- "substrate-keystore 2.0.0",
- "substrate-network 2.0.0",
  "substrate-primitives 2.0.0",
- "substrate-session 2.0.0",
+ "substrate-transaction-graph 2.0.0",
- "substrate-state-machine 2.0.0",
- "substrate-test-runtime-client 2.0.0",
- "substrate-transaction-pool 2.0.0",
- "tokio 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]

substrate/core/rpc/Cargo.toml

@@ -5,32 +5,28 @@ authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
 [dependencies]
-derive_more = "0.14.0"
+api = { package = "substrate-rpc-api", path = "./api" }
-futures = "0.1"
-futures03 = { package = "futures-preview", version = "0.3.0-alpha.17", features = ["compat"] }
-jsonrpc-core = "13.1.0"
-jsonrpc-core-client = "13.1.0"
-jsonrpc-pubsub = "13.1.0"
-jsonrpc-derive = "13.1.0"
-log = "0.4"
-parking_lot = "0.9.0"
-codec = { package = "parity-scale-codec", version = "1.0.0" }
-serde = { version = "1.0", features = ["derive"] }
-serde_json = "1.0"
 client = { package = "substrate-client", path = "../client" }
-network = { package = "substrate-network", path = "../network" }
+codec = { package = "parity-scale-codec", version = "1.0.0" }
+futures03 = { package = "futures-preview", version = "0.3.0-alpha.17", features = ["compat"] }
+jsonrpc-pubsub = "13.1.0"
+log = "0.4"
 primitives = { package = "substrate-primitives", path = "../primitives" }
-session = { package = "substrate-session", path = "../session" }
+rpc = { package = "jsonrpc-core", version = "13.0.0" }
-state_machine = { package = "substrate-state-machine", path = "../state-machine" }
-transaction_pool = { package = "substrate-transaction-pool", path = "../transaction-pool" }
-sr-primitives = { path = "../sr-primitives" }
 runtime_version = { package = "sr-version", path = "../sr-version" }
+serde_json = "1.0"
+session = { package = "substrate-session", path = "../session" }
+sr-primitives = { path = "../sr-primitives" }
+state_machine = { package = "substrate-state-machine", path = "../state-machine" }
+substrate-executor = { path = "../executor" }
 substrate-keystore = { path = "../keystore" }
+transaction_pool = { package = "substrate-transaction-pool", path = "../transaction-pool" }
 
 [dev-dependencies]
 assert_matches = "1.1"
 futures = "0.1.17"
+network = { package = "substrate-network", path = "../network" }
+rustc-hex = "2.0"
 sr-io = { path = "../sr-io" }
 test-client = { package = "substrate-test-runtime-client", path = "../test-runtime/client" }
-rustc-hex = "2.0"
 tokio = "0.1.17"

substrate/core/rpc/api/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "substrate-rpc-api"
+version = "2.0.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "1.0.0" }
+derive_more = "0.14.0"
+futures03 = { package = "futures-preview", version = "0.3.0-alpha.17", features = ["compat"] }
+jsonrpc-core = "13.0.0"
+jsonrpc-core-client = "13.0.0"
+jsonrpc-derive = "13.0.0"
+jsonrpc-pubsub = "13.0.0"
+log = "0.4"
+parking_lot = "0.9.0"
+primitives = { package = "substrate-primitives", path = "../../primitives" }
+runtime_version = { package = "sr-version", path = "../../sr-version" }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+txpool = { package = "substrate-transaction-graph", path = "../../transaction-pool/graph" }

substrate/core/rpc/api/src/author/error.rs

@@ -16,10 +16,8 @@
 
 //! Authoring RPC module errors.
 
-use client;
-use transaction_pool::txpool;
-use crate::rpc;
 use crate::errors;
+use jsonrpc_core as rpc;
 
 /// Author RPC Result type.
 pub type Result<T> = std::result::Result<T, Error>;
@@ -28,8 +26,10 @@ pub type Result<T> = std::result::Result<T, Error>;
 #[derive(Debug, derive_more::Display, derive_more::From)]
 pub enum Error {
 	/// Client error.
-	Client(client::error::Error),
+	#[display(fmt="Client error: {}", _0)]
+	Client(Box<dyn std::error::Error + Send>),
 	/// Transaction pool error,
+	#[display(fmt="Transaction pool error: {}", _0)]
 	Pool(txpool::error::Error),
 	/// Verification error
 	#[display(fmt="Extrinsic verification error: {}", _0)]
@@ -54,7 +54,7 @@ pub enum Error {
 impl std::error::Error for Error {
 	fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
 		match self {
-			Error::Client(ref err) => Some(err),
+			Error::Client(ref err) => Some(&**err),
 			Error::Pool(ref err) => Some(err),
 			Error::Verification(ref err) => Some(&**err),
 			_ => None,

substrate/core/rpc/api/src/author/mod.rs

@@ -0,0 +1,87 @@
+// Copyright 2017-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Substrate block-author/full-node API.
+
+pub mod error;
+pub mod hash;
+
+use jsonrpc_derive::rpc;
+use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
+use primitives::{
+	Bytes
+};
+use self::error::Result;
+use txpool::watcher::Status;
+
+pub use self::gen_client::Client as AuthorClient;
+
+/// Substrate authoring RPC API
+#[rpc]
+pub trait AuthorApi<Hash, BlockHash> {
+	/// RPC metadata
+	type Metadata;
+
+	/// Submit hex-encoded extrinsic for inclusion in block.
+	#[rpc(name = "author_submitExtrinsic")]
+	fn submit_extrinsic(&self, extrinsic: Bytes) -> Result<Hash>;
+
+	/// Insert a key into the keystore.
+	#[rpc(name = "author_insertKey")]
+	fn insert_key(&self,
+		key_type: String,
+		suri: String,
+		maybe_public: Option<Bytes>
+	) -> Result<Bytes>;
+
+	/// Generate new session keys and returns the corresponding public keys.
+	#[rpc(name = "author_rotateKeys")]
+	fn rotate_keys(&self) -> Result<Bytes>;
+
+	/// Returns all pending extrinsics, potentially grouped by sender.
+	#[rpc(name = "author_pendingExtrinsics")]
+	fn pending_extrinsics(&self) -> Result<Vec<Bytes>>;
+
+	/// Remove given extrinsic from the pool and temporarily ban it to prevent reimporting.
+	#[rpc(name = "author_removeExtrinsic")]
+	fn remove_extrinsic(&self,
+		bytes_or_hash: Vec<hash::ExtrinsicOrHash<Hash>>
+	) -> Result<Vec<Hash>>;
+
+	/// Submit an extrinsic to watch.
+	#[pubsub(
+		subscription = "author_extrinsicUpdate",
+		subscribe,
+		name = "author_submitAndWatchExtrinsic"
+	)]
+	fn watch_extrinsic(&self,
+		metadata: Self::Metadata,
+		subscriber: Subscriber<Status<Hash, BlockHash>>,
+		bytes: Bytes
+	);
+
+	/// Unsubscribe from extrinsic watching.
+	#[pubsub(
+		subscription = "author_extrinsicUpdate",
+		unsubscribe,
+		name = "author_unwatchExtrinsic"
+	)]
+	fn unwatch_extrinsic(&self,
+		metadata: Option<Self::Metadata>,
+		id: SubscriptionId
+	) -> Result<bool>;
+}
+

substrate/core/rpc/api/src/chain/error.rs

@@ -17,9 +17,8 @@
 
 //! Error helpers for Chain RPC module.
 
-use client;
-use crate::rpc;
 use crate::errors;
+use jsonrpc_core as rpc;
 
 /// Chain RPC Result type.
 pub type Result<T> = std::result::Result<T, Error>;
@@ -28,7 +27,8 @@ pub type Result<T> = std::result::Result<T, Error>;
 #[derive(Debug, derive_more::Display, derive_more::From)]
 pub enum Error {
 	/// Client error.
-	Client(client::error::Error),
+	#[display(fmt="Client error: {}", _0)]
+	Client(Box<dyn std::error::Error + Send>),
 	/// Other error type.
 	Other(String),
 }
@@ -36,7 +36,7 @@ pub enum Error {
 impl std::error::Error for Error {
 	fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
 		match self {
-			Error::Client(ref err) => Some(err),
+			Error::Client(ref err) => Some(&**err),
 			_ => None,
 		}
 	}

substrate/core/rpc/api/src/chain/mod.rs

@@ -0,0 +1,89 @@
+// Copyright 2017-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Substrate blockchain API.
+
+pub mod error;
+pub mod number;
+
+use jsonrpc_core::Result as RpcResult;
+use jsonrpc_core::futures::Future;
+use jsonrpc_derive::rpc;
+use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
+use self::error::Result;
+
+pub use self::gen_client::Client as ChainClient;
+
+/// Substrate blockchain API
+#[rpc]
+pub trait ChainApi<Number, Hash, Header, SignedBlock> {
+	/// RPC metadata
+	type Metadata;
+
+	/// Get header of a relay chain block.
+	#[rpc(name = "chain_getHeader")]
+	fn header(&self, hash: Option<Hash>) -> Result<Option<Header>>;
+
+	/// Get header and body of a relay chain block.
+	#[rpc(name = "chain_getBlock")]
+	fn block(&self, hash: Option<Hash>) -> Result<Option<SignedBlock>>;
+
+	/// Get hash of the n-th block in the canon chain.
+	///
+	/// By default returns latest block hash.
+	#[rpc(name = "chain_getBlockHash", alias("chain_getHead"))]
+	fn block_hash(&self, hash: Option<number::NumberOrHex<Number>>) -> Result<Option<Hash>>;
+
+	/// Get hash of the last finalized block in the canon chain.
+	#[rpc(name = "chain_getFinalizedHead", alias("chain_getFinalisedHead"))]
+	fn finalized_head(&self) -> Result<Hash>;
+
+	/// New head subscription
+	#[pubsub(
+		subscription = "chain_newHead",
+		subscribe,
+		name = "chain_subscribeNewHeads",
+		alias("subscribe_newHead", "chain_subscribeNewHead")
+	)]
+	fn subscribe_new_heads(&self, metadata: Self::Metadata, subscriber: Subscriber<Header>);
+
+	/// Unsubscribe from new head subscription.
+	#[pubsub(
+		subscription = "chain_newHead",
+		unsubscribe,
+		name = "chain_unsubscribeNewHeads",
+		alias("unsubscribe_newHead", "chain_unsubscribeNewHead")
+	)]
+	fn unsubscribe_new_heads(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
+
+	/// New head subscription
+	#[pubsub(
+		subscription = "chain_finalizedHead",
+		subscribe,
+		name = "chain_subscribeFinalizedHeads",
+		alias("chain_subscribeFinalisedHeads")
+	)]
+	fn subscribe_finalized_heads(&self, metadata: Self::Metadata, subscriber: Subscriber<Header>);
+
+	/// Unsubscribe from new head subscription.
+	#[pubsub(
+		subscription = "chain_finalizedHead",
+		unsubscribe,
+		name = "chain_unsubscribeFinalizedHeads",
+		alias("chain_unsubscribeFinalisedHeads")
+	)]
+	fn unsubscribe_finalized_heads(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
+}

substrate/core/rpc/api/src/chain/number.rs

@@ -61,14 +61,12 @@ impl<Number: TryFrom<u64> + From<u32> + Debug + PartialOrd> NumberOrHex<Number>
 	}
 }
 
-#[cfg(test)]
 impl From<u64> for NumberOrHex<u64> {
 	fn from(n: u64) -> Self {
 		NumberOrHex::Number(n)
 	}
 }
 
-#[cfg(test)]
 impl<Number> From<U256> for NumberOrHex<Number> {
 	fn from(n: U256) -> Self {
 		NumberOrHex::Hex(n)

substrate/core/rpc/api/src/errors.rs

@@ -14,13 +14,12 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-use crate::rpc;
 use log::warn;
 
-pub fn internal<E: ::std::fmt::Debug>(e: E) -> rpc::Error {
+pub fn internal<E: ::std::fmt::Debug>(e: E) -> jsonrpc_core::Error {
 	warn!("Unknown error: {:?}", e);
-	rpc::Error {
+	jsonrpc_core::Error {
-		code: rpc::ErrorCode::InternalError,
+		code: jsonrpc_core::ErrorCode::InternalError,
 		message: "Unknown error occured".into(),
 		data: Some(format!("{:?}", e).into()),
 	}

substrate/core/rpc/api/src/helpers.rs

@@ -0,0 +1,31 @@
+// Copyright 2018-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+use jsonrpc_core::futures::prelude::*;
+use futures03::{channel::oneshot, compat::Compat};
+
+/// Wraps around `oneshot::Receiver` and adjusts the error type to produce an internal error if the
+/// sender gets dropped.
+pub struct Receiver<T>(pub Compat<oneshot::Receiver<T>>);
+
+impl<T> Future for Receiver<T> {
+	type Item = T;
+	type Error = jsonrpc_core::Error;
+
+	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+		self.0.poll().map_err(|_| jsonrpc_core::Error::internal_error())
+	}
+}

substrate/core/rpc/api/src/lib.rs

@@ -0,0 +1,34 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Substrate RPC interfaces.
+//!
+//! A collection of RPC methods and subscriptions supported by all substrate clients.
+
+#![warn(missing_docs)]
+
+mod errors;
+mod helpers;
+mod subscriptions;
+
+pub use jsonrpc_core::IoHandlerExtension as RpcExtension;
+pub use subscriptions::Subscriptions;
+pub use helpers::Receiver;
+
+pub mod author;
+pub mod chain;
+pub mod state;
+pub mod system;

substrate/core/rpc/api/src/state/error.rs

@@ -16,9 +16,8 @@
 
 //! State RPC errors.
 
-use client;
-use crate::rpc;
 use crate::errors;
+use jsonrpc_core as rpc;
 
 /// State RPC Result type.
 pub type Result<T> = std::result::Result<T, Error>;
@@ -27,7 +26,8 @@ pub type Result<T> = std::result::Result<T, Error>;
 #[derive(Debug, derive_more::Display, derive_more::From)]
 pub enum Error {
 	/// Client error.
-	Client(client::error::Error),
+	#[display(fmt="Client error: {}", _0)]
+	Client(Box<dyn std::error::Error + Send>),
 	/// Provided block range couldn't be resolved to a list of blocks.
 	#[display(fmt = "Cannot resolve a block range ['{:?}' ... '{:?}]. {}", from, to, details)]
 	InvalidBlockRange {
@@ -43,7 +43,7 @@ pub enum Error {
 impl std::error::Error for Error {
 	fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
 		match self {
-			Error::Client(ref err) => Some(err),
+			Error::Client(ref err) => Some(&**err),
 			_ => None,
 		}
 	}

substrate/core/rpc/api/src/state/mod.rs

@@ -0,0 +1,143 @@
+// Copyright 2017-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Substrate state API.
+
+pub mod error;
+
+use jsonrpc_core::Result as RpcResult;
+use jsonrpc_core::futures::Future;
+use jsonrpc_derive::rpc;
+use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
+use primitives::Bytes;
+use primitives::storage::{StorageKey, StorageData, StorageChangeSet};
+use runtime_version::RuntimeVersion;
+use self::error::Result;
+
+pub use self::gen_client::Client as StateClient;
+
+/// Substrate state API
+#[rpc]
+pub trait StateApi<Hash> {
+	/// RPC Metadata
+	type Metadata;
+
+	/// Call a contract at a block's state.
+	#[rpc(name = "state_call", alias("state_callAt"))]
+	fn call(&self, name: String, bytes: Bytes, hash: Option<Hash>) -> Result<Bytes>;
+
+	/// Returns the keys with prefix, leave empty to get all the keys
+	#[rpc(name = "state_getKeys")]
+	fn storage_keys(&self, prefix: StorageKey, hash: Option<Hash>) -> Result<Vec<StorageKey>>;
+
+	/// Returns a storage entry at a specific block's state.
+	#[rpc(name = "state_getStorage", alias("state_getStorageAt"))]
+	fn storage(&self, key: StorageKey, hash: Option<Hash>) -> Result<Option<StorageData>>;
+
+	/// Returns the hash of a storage entry at a block's state.
+	#[rpc(name = "state_getStorageHash", alias("state_getStorageHashAt"))]
+	fn storage_hash(&self, key: StorageKey, hash: Option<Hash>) -> Result<Option<Hash>>;
+
+	/// Returns the size of a storage entry at a block's state.
+	#[rpc(name = "state_getStorageSize", alias("state_getStorageSizeAt"))]
+	fn storage_size(&self, key: StorageKey, hash: Option<Hash>) -> Result<Option<u64>>;
+
+	/// Returns the keys with prefix from a child storage, leave empty to get all the keys
+	#[rpc(name = "state_getChildKeys")]
+	fn child_storage_keys(
+		&self,
+		child_storage_key: StorageKey,
+		prefix: StorageKey,
+		hash: Option<Hash>
+	) -> Result<Vec<StorageKey>>;
+
+	/// Returns a child storage entry at a specific block's state.
+	#[rpc(name = "state_getChildStorage")]
+	fn child_storage(
+		&self,
+		child_storage_key: StorageKey,
+		key: StorageKey,
+		hash: Option<Hash>
+	) -> Result<Option<StorageData>>;
+
+	/// Returns the hash of a child storage entry at a block's state.
+	#[rpc(name = "state_getChildStorageHash")]
+	fn child_storage_hash(
+		&self,
+		child_storage_key: StorageKey,
+		key: StorageKey,
+		hash: Option<Hash>
+	) -> Result<Option<Hash>>;
+
+	/// Returns the size of a child storage entry at a block's state.
+	#[rpc(name = "state_getChildStorageSize")]
+	fn child_storage_size(
+		&self,
+		child_storage_key: StorageKey,
+		key: StorageKey,
+		hash: Option<Hash>
+	) -> Result<Option<u64>>;
+
+	/// Returns the runtime metadata as an opaque blob.
+	#[rpc(name = "state_getMetadata")]
+	fn metadata(&self, hash: Option<Hash>) -> Result<Bytes>;
+
+	/// Get the runtime version.
+	#[rpc(name = "state_getRuntimeVersion", alias("chain_getRuntimeVersion"))]
+	fn runtime_version(&self, hash: Option<Hash>) -> Result<RuntimeVersion>;
+
+	/// Query historical storage entries (by key) starting from a block given as the second parameter.
+	///
+	/// NOTE This first returned result contains the initial state of storage for all keys.
+	/// Subsequent values in the vector represent changes to the previous state (diffs).
+	#[rpc(name = "state_queryStorage")]
+	fn query_storage(
+		&self,
+		keys: Vec<StorageKey>,
+		block: Hash,
+		hash: Option<Hash>
+	) -> Result<Vec<StorageChangeSet<Hash>>>;
+
+	/// New runtime version subscription
+	#[pubsub(
+		subscription = "state_runtimeVersion",
+		subscribe,
+		name = "state_subscribeRuntimeVersion",
+		alias("chain_subscribeRuntimeVersion")
+	)]
+	fn subscribe_runtime_version(&self, metadata: Self::Metadata, subscriber: Subscriber<RuntimeVersion>);
+
+	/// Unsubscribe from runtime version subscription
+	#[pubsub(
+		subscription = "state_runtimeVersion",
+		unsubscribe,
+		name = "state_unsubscribeRuntimeVersion",
+		alias("chain_unsubscribeRuntimeVersion")
+	)]
+	fn unsubscribe_runtime_version(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
+
+	/// New storage subscription
+	#[pubsub(subscription = "state_storage", subscribe, name = "state_subscribeStorage")]
+	fn subscribe_storage(
+		&self, metadata: Self::Metadata, subscriber: Subscriber<StorageChangeSet<Hash>>, keys: Option<Vec<StorageKey>>
+	);
+
+	/// Unsubscribe from storage subscription
+	#[pubsub(subscription = "state_storage", unsubscribe, name = "state_unsubscribeStorage")]
+	fn unsubscribe_storage(
+		&self, metadata: Option<Self::Metadata>, id: SubscriptionId
+	) -> RpcResult<bool>;
+}

substrate/core/rpc/api/src/subscriptions.rs

@@ -20,8 +20,8 @@ use std::sync::{Arc, atomic::{self, AtomicUsize}};
 use log::{error, warn};
 use jsonrpc_pubsub::{SubscriptionId, typed::{Sink, Subscriber}};
 use parking_lot::Mutex;
-use crate::rpc::futures::sync::oneshot;
+use jsonrpc_core::futures::sync::oneshot;
-use crate::rpc::futures::{Future, future};
+use jsonrpc_core::futures::{Future, future};
 
 type Id = u64;
 

substrate/core/rpc/api/src/system/error.rs

@@ -16,8 +16,8 @@
 
 //! System RPC module errors.
 
-use crate::rpc;
 use crate::system::helpers::Health;
+use jsonrpc_core as rpc;
 
 /// System RPC Result type.
 pub type Result<T> = std::result::Result<T, Error>;

substrate/core/rpc/api/src/system/mod.rs

@@ -0,0 +1,67 @@
+// Copyright 2017-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Substrate system API.
+
+pub mod error;
+pub mod helpers;
+
+use crate::helpers::Receiver;
+use jsonrpc_derive::rpc;
+
+use self::error::Result;
+
+pub use self::helpers::{Properties, SystemInfo, Health, PeerInfo};
+pub use self::gen_client::Client as SystemClient;
+
+/// Substrate system RPC API
+#[rpc]
+pub trait SystemApi<Hash, Number> {
+	/// Get the node's implementation name. Plain old string.
+	#[rpc(name = "system_name")]
+	fn system_name(&self) -> Result<String>;
+
+	/// Get the node implementation's version. Should be a semver string.
+	#[rpc(name = "system_version")]
+	fn system_version(&self) -> Result<String>;
+
+	/// Get the chain's type. Given as a string identifier.
+	#[rpc(name = "system_chain")]
+	fn system_chain(&self) -> Result<String>;
+
+	/// Get a custom set of properties as a JSON object, defined in the chain spec.
+	#[rpc(name = "system_properties")]
+	fn system_properties(&self) -> Result<Properties>;
+
+	/// Return health status of the node.
+	///
+	/// Node is considered healthy if it is:
+	/// - connected to some peers (unless running in dev mode)
+	/// - not performing a major sync
+	#[rpc(name = "system_health", returns = "Health")]
+	fn system_health(&self) -> Receiver<Health>;
+
+	/// Returns currently connected peers
+	#[rpc(name = "system_peers", returns = "Vec<PeerInfo<Hash, Number>>")]
+	fn system_peers(&self) -> Receiver<Vec<PeerInfo<Hash, Number>>>;
+
+	/// Returns current state of the network.
+	///
+	/// **Warning**: This API is not stable.
+	// TODO: make this stable and move structs https://github.com/paritytech/substrate/issues/1890
+	#[rpc(name = "system_networkState", returns = "jsonrpc_core::Value")]
+	fn system_network_state(&self) -> Receiver<jsonrpc_core::Value>;
+}

substrate/core/rpc/src/author/mod.rs

@@ -16,19 +16,15 @@
 
 //! Substrate block-author/full-node API.
 
-pub mod error;
-pub mod hash;
-
 #[cfg(test)]
 mod tests;
 
 use std::{sync::Arc, convert::TryInto};
 
 use client::{self, Client};
-use crate::rpc::futures::{Sink, Future};
+use rpc::futures::{Sink, Future};
-use crate::subscriptions::Subscriptions;
 use futures03::{StreamExt as _, compat::Compat};
-use jsonrpc_derive::rpc;
+use api::Subscriptions;
 use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
 use log::warn;
 use codec::{Encode, Decode};
@@ -37,7 +33,6 @@ use primitives::{
 	traits::BareCryptoStorePtr,
 };
 use sr_primitives::{generic, traits::{self, ProvideRuntimeApi}};
-use self::error::{Error, Result};
 use transaction_pool::{
 	txpool::{
 		ChainApi as PoolChainApi,
@@ -50,63 +45,9 @@ use transaction_pool::{
 };
 use session::SessionKeys;
 
-pub use self::gen_client::Client as AuthorClient;
+/// Re-export the API for backward compatibility.
-
+pub use api::author::*;
-/// Substrate authoring RPC API
+use self::error::{Error, Result};
-#[rpc]
-pub trait AuthorApi<Hash, BlockHash> {
-	/// RPC metadata
-	type Metadata;
-
-	/// Submit hex-encoded extrinsic for inclusion in block.
-	#[rpc(name = "author_submitExtrinsic")]
-	fn submit_extrinsic(&self, extrinsic: Bytes) -> Result<Hash>;
-
-	/// Insert a key into the keystore.
-	#[rpc(name = "author_insertKey")]
-	fn insert_key(&self,
-		key_type: String,
-		suri: String,
-		maybe_public: Option<Bytes>
-	) -> Result<Bytes>;
-
-	/// Generate new session keys and returns the corresponding public keys.
-	#[rpc(name = "author_rotateKeys")]
-	fn rotate_keys(&self) -> Result<Bytes>;
-
-	/// Returns all pending extrinsics, potentially grouped by sender.
-	#[rpc(name = "author_pendingExtrinsics")]
-	fn pending_extrinsics(&self) -> Result<Vec<Bytes>>;
-
-	/// Remove given extrinsic from the pool and temporarily ban it to prevent reimporting.
-	#[rpc(name = "author_removeExtrinsic")]
-	fn remove_extrinsic(&self,
-		bytes_or_hash: Vec<hash::ExtrinsicOrHash<Hash>>
-	) -> Result<Vec<Hash>>;
-
-	/// Submit an extrinsic to watch.
-	#[pubsub(
-		subscription = "author_extrinsicUpdate",
-		subscribe,
-		name = "author_submitAndWatchExtrinsic"
-	)]
-	fn watch_extrinsic(&self,
-		metadata: Self::Metadata,
-		subscriber: Subscriber<Status<Hash, BlockHash>>,
-		bytes: Bytes
-	);
-
-	/// Unsubscribe from extrinsic watching.
-	#[pubsub(
-		subscription = "author_extrinsicUpdate",
-		unsubscribe,
-		name = "author_unwatchExtrinsic"
-	)]
-	fn unwatch_extrinsic(&self,
-		metadata: Option<Self::Metadata>,
-		id: SubscriptionId
-	) -> Result<bool>;
-}
 
 /// Authoring API
 pub struct Author<B, E, P, RA> where P: PoolChainApi + Sync + Send + 'static {
@@ -183,7 +124,7 @@ impl<B, E, P, RA> AuthorApi<ExHash<P>, BlockHash<P>> for Author<B, E, P, RA> whe
 		self.client.runtime_api().generate_session_keys(
 			&generic::BlockId::Hash(best_block_hash),
 			None,
-		).map(Into::into).map_err(Into::into)
+		).map(Into::into).map_err(|e| Error::Client(Box::new(e)))
 	}
 
 	fn submit_extrinsic(&self, ext: Bytes) -> Result<ExHash<P>> {

substrate/core/rpc/src/chain/mod.rs

@@ -16,9 +16,6 @@
 
 //! Substrate blockchain API.
 
-pub mod error;
-pub mod number;
-
 #[cfg(test)]
 mod tests;
 
@@ -26,79 +23,17 @@ use std::sync::Arc;
 use futures03::{future, StreamExt as _, TryStreamExt as _};
 
 use client::{self, Client, BlockchainEvents};
-use crate::rpc::Result as RpcResult;
+use rpc::Result as RpcResult;
-use crate::rpc::futures::{stream, Future, Sink, Stream};
+use rpc::futures::{stream, Future, Sink, Stream};
-use crate::subscriptions::Subscriptions;
+use api::Subscriptions;
-use jsonrpc_derive::rpc;
 use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
 use log::warn;
 use primitives::{H256, Blake2Hasher};
 use sr_primitives::generic::{BlockId, SignedBlock};
 use sr_primitives::traits::{Block as BlockT, Header, NumberFor};
-use self::error::Result;
+use self::error::{Error, Result};
 
-pub use self::gen_client::Client as ChainClient;
+pub use api::chain::*;
-
-/// Substrate blockchain API
-#[rpc]
-pub trait ChainApi<Number, Hash, Header, SignedBlock> {
-	/// RPC metadata
-	type Metadata;
-
-	/// Get header of a relay chain block.
-	#[rpc(name = "chain_getHeader")]
-	fn header(&self, hash: Option<Hash>) -> Result<Option<Header>>;
-
-	/// Get header and body of a relay chain block.
-	#[rpc(name = "chain_getBlock")]
-	fn block(&self, hash: Option<Hash>) -> Result<Option<SignedBlock>>;
-
-	/// Get hash of the n-th block in the canon chain.
-	///
-	/// By default returns latest block hash.
-	#[rpc(name = "chain_getBlockHash", alias("chain_getHead"))]
-	fn block_hash(&self, hash: Option<number::NumberOrHex<Number>>) -> Result<Option<Hash>>;
-
-	/// Get hash of the last finalized block in the canon chain.
-	#[rpc(name = "chain_getFinalizedHead", alias("chain_getFinalisedHead"))]
-	fn finalized_head(&self) -> Result<Hash>;
-
-	/// New head subscription
-	#[pubsub(
-		subscription = "chain_newHead",
-		subscribe,
-		name = "chain_subscribeNewHeads",
-		alias("subscribe_newHead", "chain_subscribeNewHead")
-	)]
-	fn subscribe_new_heads(&self, metadata: Self::Metadata, subscriber: Subscriber<Header>);
-
-	/// Unsubscribe from new head subscription.
-	#[pubsub(
-		subscription = "chain_newHead",
-		unsubscribe,
-		name = "chain_unsubscribeNewHeads",
-		alias("unsubscribe_newHead", "chain_unsubscribeNewHead")
-	)]
-	fn unsubscribe_new_heads(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
-
-	/// New head subscription
-	#[pubsub(
-		subscription = "chain_finalizedHead",
-		subscribe,
-		name = "chain_subscribeFinalizedHeads",
-		alias("chain_subscribeFinalisedHeads")
-	)]
-	fn subscribe_finalized_heads(&self, metadata: Self::Metadata, subscriber: Subscriber<Header>);
-
-	/// Unsubscribe from new head subscription.
-	#[pubsub(
-		subscription = "chain_finalizedHead",
-		unsubscribe,
-		name = "chain_unsubscribeFinalizedHeads",
-		alias("chain_unsubscribeFinalisedHeads")
-	)]
-	fn unsubscribe_finalized_heads(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
-}
 
 /// Chain API with subscriptions support.
 pub struct Chain<B, E, Block: BlockT, RA> {
@@ -168,6 +103,10 @@ impl<B, E, Block, RA> Chain<B, E, Block, RA> where
 	}
 }
 
+fn client_error(err: client::error::Error) -> Error {
+	Error::Client(Box::new(err))
+}
+
 impl<B, E, Block, RA> ChainApi<NumberFor<Block>, Block::Hash, Block::Header, SignedBlock<Block>> for Chain<B, E, Block, RA> where
 	Block: BlockT<Hash=H256> + 'static,
 	B: client::backend::Backend<Block, Blake2Hasher> + Send + Sync + 'static,
@@ -178,20 +117,23 @@ impl<B, E, Block, RA> ChainApi<NumberFor<Block>, Block::Hash, Block::Header, Sig
 
 	fn header(&self, hash: Option<Block::Hash>) -> Result<Option<Block::Header>> {
 		let hash = self.unwrap_or_best(hash)?;
-		Ok(self.client.header(&BlockId::Hash(hash))?)
+		Ok(self.client.header(&BlockId::Hash(hash)).map_err(client_error)?)
 	}
 
 	fn block(&self, hash: Option<Block::Hash>)
 		-> Result<Option<SignedBlock<Block>>>
 	{
 		let hash = self.unwrap_or_best(hash)?;
-		Ok(self.client.block(&BlockId::Hash(hash))?)
+		Ok(self.client.block(&BlockId::Hash(hash)).map_err(client_error)?)
 	}
 
 	fn block_hash(&self, number: Option<number::NumberOrHex<NumberFor<Block>>>) -> Result<Option<Block::Hash>> {
 		Ok(match number {
 			None => Some(self.client.info().chain.best_hash),
-			Some(num_or_hex) => self.client.header(&BlockId::number(num_or_hex.to_number()?))?.map(|h| h.hash()),
+			Some(num_or_hex) => self.client
+				.header(&BlockId::number(num_or_hex.to_number()?))
+				.map_err(client_error)?
+				.map(|h| h.hash()),
 		})
 	}
 

substrate/core/rpc/src/helpers.rs

@@ -14,22 +14,6 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-use futures::prelude::*;
-use futures03::{channel::oneshot, compat::Compat};
-
-/// Wraps around `oneshot::Receiver` and adjusts the error type to produce an internal error if the
-/// sender gets dropped.
-pub struct Receiver<T>(pub Compat<oneshot::Receiver<T>>);
-
-impl<T> Future for Receiver<T> {
-	type Item = T;
-	type Error = jsonrpc_core::Error;
-
-	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-		self.0.poll().map_err(|_| jsonrpc_core::Error::internal_error())
-	}
-}
-
 /// Unwraps the trailing parameter or falls back with the closure result.
 pub fn unwrap_or_else<F, H, E>(or_else: F, optional: Option<H>) -> Result<H, E> where
 	F: FnOnce() -> Result<H, E>,

substrate/core/rpc/src/lib.rs

@@ -14,22 +14,18 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Substrate RPC interfaces.
+//! Substrate RPC implementation.
 //!
-//! A collection of RPC methods and subscriptions supported by all substrate clients.
+//! A core implementation of Substrate RPC interfaces.
 
 #![warn(missing_docs)]
 
-mod errors;
 mod helpers;
 mod metadata;
-mod subscriptions;
 
-use jsonrpc_core as rpc;
+pub use api::Subscriptions;
-
+pub use self::metadata::Metadata;
-pub use metadata::Metadata;
 pub use rpc::IoHandlerExtension as RpcExtension;
-pub use subscriptions::Subscriptions;
 
 pub mod author;
 pub mod chain;

substrate/core/rpc/src/metadata.rs

@@ -18,7 +18,7 @@
 use std::sync::Arc;
 
 use jsonrpc_pubsub::{Session, PubSubMetadata};
-use crate::rpc::futures::sync::mpsc;
+use rpc::futures::sync::mpsc;
 
 /// RPC Metadata.
 ///
@@ -30,7 +30,7 @@ pub struct Metadata {
 	session: Option<Arc<Session>>,
 }
 
-impl crate::rpc::Metadata for Metadata {}
+impl rpc::Metadata for Metadata {}
 impl PubSubMetadata for Metadata {
 	fn session(&self) -> Option<Arc<Session>> {
 		self.session.clone()

substrate/core/rpc/src/state/mod.rs

@@ -16,8 +16,6 @@
 
 //! Substrate state API.
 
-pub mod error;
-
 #[cfg(test)]
 mod tests;
 
@@ -29,10 +27,9 @@ use std::{
 use futures03::{future, StreamExt as _, TryStreamExt as _};
 
 use client::{self, Client, CallExecutor, BlockchainEvents, runtime_api::Metadata};
-use crate::rpc::Result as RpcResult;
+use rpc::Result as RpcResult;
-use crate::rpc::futures::{stream, Future, Sink, Stream};
+use rpc::futures::{stream, Future, Sink, Stream};
-use crate::subscriptions::Subscriptions;
+use api::Subscriptions;
-use jsonrpc_derive::rpc;
 use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
 use log::{warn, trace};
 use primitives::hexdisplay::HexDisplay;
@@ -44,123 +41,10 @@ use sr_primitives::traits::{
 	SaturatedConversion
 };
 use runtime_version::RuntimeVersion;
-use self::error::Result;
+use self::error::{Error, Result};
 use state_machine::{self, ExecutionStrategy};
 
-pub use self::gen_client::Client as StateClient;
+pub use api::state::*;
-
-/// Substrate state API
-#[rpc]
-pub trait StateApi<Hash> {
-	/// RPC Metadata
-	type Metadata;
-
-	/// Call a contract at a block's state.
-	#[rpc(name = "state_call", alias("state_callAt"))]
-	fn call(&self, name: String, bytes: Bytes, hash: Option<Hash>) -> Result<Bytes>;
-
-	/// Returns the keys with prefix, leave empty to get all the keys
-	#[rpc(name = "state_getKeys")]
-	fn storage_keys(&self, prefix: StorageKey, hash: Option<Hash>) -> Result<Vec<StorageKey>>;
-
-	/// Returns a storage entry at a specific block's state.
-	#[rpc(name = "state_getStorage", alias("state_getStorageAt"))]
-	fn storage(&self, key: StorageKey, hash: Option<Hash>) -> Result<Option<StorageData>>;
-
-	/// Returns the hash of a storage entry at a block's state.
-	#[rpc(name = "state_getStorageHash", alias("state_getStorageHashAt"))]
-	fn storage_hash(&self, key: StorageKey, hash: Option<Hash>) -> Result<Option<Hash>>;
-
-	/// Returns the size of a storage entry at a block's state.
-	#[rpc(name = "state_getStorageSize", alias("state_getStorageSizeAt"))]
-	fn storage_size(&self, key: StorageKey, hash: Option<Hash>) -> Result<Option<u64>>;
-
-	/// Returns the keys with prefix from a child storage, leave empty to get all the keys
-	#[rpc(name = "state_getChildKeys")]
-	fn child_storage_keys(
-		&self,
-		child_storage_key: StorageKey,
-		prefix: StorageKey,
-		hash: Option<Hash>
-	) -> Result<Vec<StorageKey>>;
-
-	/// Returns a child storage entry at a specific block's state.
-	#[rpc(name = "state_getChildStorage")]
-	fn child_storage(
-		&self,
-		child_storage_key: StorageKey,
-		key: StorageKey,
-		hash: Option<Hash>
-	) -> Result<Option<StorageData>>;
-
-	/// Returns the hash of a child storage entry at a block's state.
-	#[rpc(name = "state_getChildStorageHash")]
-	fn child_storage_hash(
-		&self,
-		child_storage_key: StorageKey,
-		key: StorageKey,
-		hash: Option<Hash>
-	) -> Result<Option<Hash>>;
-
-	/// Returns the size of a child storage entry at a block's state.
-	#[rpc(name = "state_getChildStorageSize")]
-	fn child_storage_size(
-		&self,
-		child_storage_key: StorageKey,
-		key: StorageKey,
-		hash: Option<Hash>
-	) -> Result<Option<u64>>;
-
-	/// Returns the runtime metadata as an opaque blob.
-	#[rpc(name = "state_getMetadata")]
-	fn metadata(&self, hash: Option<Hash>) -> Result<Bytes>;
-
-	/// Get the runtime version.
-	#[rpc(name = "state_getRuntimeVersion", alias("chain_getRuntimeVersion"))]
-	fn runtime_version(&self, hash: Option<Hash>) -> Result<RuntimeVersion>;
-
-	/// Query historical storage entries (by key) starting from a block given as the second parameter.
-	///
-	/// NOTE This first returned result contains the initial state of storage for all keys.
-	/// Subsequent values in the vector represent changes to the previous state (diffs).
-	#[rpc(name = "state_queryStorage")]
-	fn query_storage(
-		&self,
-		keys: Vec<StorageKey>,
-		block: Hash,
-		hash: Option<Hash>
-	) -> Result<Vec<StorageChangeSet<Hash>>>;
-
-	/// New runtime version subscription
-	#[pubsub(
-		subscription = "state_runtimeVersion",
-		subscribe,
-		name = "state_subscribeRuntimeVersion",
-		alias("chain_subscribeRuntimeVersion")
-	)]
-	fn subscribe_runtime_version(&self, metadata: Self::Metadata, subscriber: Subscriber<RuntimeVersion>);
-
-	/// Unsubscribe from runtime version subscription
-	#[pubsub(
-		subscription = "state_runtimeVersion",
-		unsubscribe,
-		name = "state_unsubscribeRuntimeVersion",
-		alias("chain_unsubscribeRuntimeVersion")
-	)]
-	fn unsubscribe_runtime_version(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
-
-	/// New storage subscription
-	#[pubsub(subscription = "state_storage", subscribe, name = "state_subscribeStorage")]
-	fn subscribe_storage(
-		&self, metadata: Self::Metadata, subscriber: Subscriber<StorageChangeSet<Hash>>, keys: Option<Vec<StorageKey>>
-	);
-
-	/// Unsubscribe from storage subscription
-	#[pubsub(subscription = "state_storage", unsubscribe, name = "state_unsubscribeStorage")]
-	fn unsubscribe_storage(
-		&self, metadata: Option<Self::Metadata>, id: SubscriptionId
-	) -> RpcResult<bool>;
-}
 
 /// State API with subscriptions support.
 pub struct State<B, E, Block: BlockT, RA> {
@@ -184,6 +68,10 @@ struct QueryStorageRange<Block: BlockT> {
 	pub filtered_range: Option<Range<usize>>,
 }
 
+fn client_err(err: client::error::Error) -> Error {
+	Error::Client(Box::new(err))
+}
+
 impl<B, E, Block: BlockT, RA> State<B, E, Block, RA> where
 	Block: BlockT<Hash=H256>,
 	B: client::backend::Backend<Block, Blake2Hasher>,
@@ -206,8 +94,8 @@ impl<B, E, Block: BlockT, RA> State<B, E, Block, RA> where
 		to: Option<Block::Hash>
 	) -> Result<QueryStorageRange<Block>> {
 		let to = self.unwrap_or_best(to)?;
-		let from_hdr = self.client.header(&BlockId::hash(from))?;
+		let from_hdr = self.client.header(&BlockId::hash(from)).map_err(client_err)?;
-		let to_hdr = self.client.header(&BlockId::hash(to))?;
+		let to_hdr = self.client.header(&BlockId::hash(to)).map_err(client_err)?;
 		match (from_hdr, to_hdr) {
 			(Some(ref from), Some(ref to)) if from.number() <= to.number() => {
 				// check if we can get from `to` to `from` by going through parent_hashes.
@@ -216,7 +104,10 @@ impl<B, E, Block: BlockT, RA> State<B, E, Block, RA> where
 					let mut blocks = vec![to.hash()];
 					let mut last = to.clone();
 					while *last.number() > from_number {
-						if let Some(hdr) = self.client.header(&BlockId::hash(*last.parent_hash()))? {
+						let hdr = self.client
+							.header(&BlockId::hash(*last.parent_hash()))
+							.map_err(client_err)?;
+						if let Some(hdr) = hdr {
 							blocks.push(hdr.hash());
 							last = hdr;
 						} else {
@@ -238,7 +129,9 @@ impl<B, E, Block: BlockT, RA> State<B, E, Block, RA> where
 					blocks
 				};
 				// check if we can filter blocks-with-changes from some (sub)range using changes tries
-				let changes_trie_range = self.client.max_key_changes_range(from_number, BlockId::Hash(to.hash()))?;
+				let changes_trie_range = self.client
+					.max_key_changes_range(from_number, BlockId::Hash(to.hash()))
+					.map_err(client_err)?;
 				let filtered_range_begin = changes_trie_range.map(|(begin, _)| (begin - from_number).saturated_into::<usize>());
 				let (unfiltered_range, filtered_range) = split_range(blocks.len(), filtered_range_begin);
 				Ok(QueryStorageRange {
@@ -268,7 +161,8 @@ impl<B, E, Block: BlockT, RA> State<B, E, Block, RA> where
 			let id = BlockId::hash(block_hash);
 			for key in keys {
 				let (has_changed, data) = {
-					let curr_data = self.client.storage(&id, key)?;
+					let curr_data = self.client.storage(&id, key)
+						.map_err(client_err)?;
 					match last_values.get(key) {
 						Some(prev_data) => (curr_data != *prev_data, curr_data),
 						None => (true, curr_data),
@@ -305,14 +199,14 @@ impl<B, E, Block: BlockT, RA> State<B, E, Block, RA> where
 		for key in keys {
 			let mut last_block = None;
 			let mut last_value = last_values.get(key).cloned().unwrap_or_default();
-			for (block, _) in self.client.key_changes(begin, end, key)?.into_iter().rev() {
+			for (block, _) in self.client.key_changes(begin, end, key).map_err(client_err)?.into_iter().rev() {
 				if last_block == Some(block) {
 					continue;
 				}
 
 				let block_hash = range.hashes[(block - range.first_number).saturated_into::<usize>()].clone();
 				let id = BlockId::Hash(block_hash);
-				let value_at_block = self.client.storage(&id, key)?;
+				let value_at_block = self.client.storage(&id, key).map_err(client_err)?;
 				if last_value == value_at_block {
 					continue;
 				}
@@ -360,26 +254,27 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 			.call(
 				&BlockId::Hash(block),
 				&method, &data.0, ExecutionStrategy::NativeElseWasm, state_machine::NeverOffchainExt::new(),
-			)?;
+			)
+			.map_err(client_err)?;
 		Ok(Bytes(return_data))
 	}
 
 	fn storage_keys(&self, key_prefix: StorageKey, block: Option<Block::Hash>) -> Result<Vec<StorageKey>> {
 		let block = self.unwrap_or_best(block)?;
 		trace!(target: "rpc", "Querying storage keys at {:?}", block);
-		Ok(self.client.storage_keys(&BlockId::Hash(block), &key_prefix)?)
+		Ok(self.client.storage_keys(&BlockId::Hash(block), &key_prefix).map_err(client_err)?)
 	}
 
 	fn storage(&self, key: StorageKey, block: Option<Block::Hash>) -> Result<Option<StorageData>> {
 		let block = self.unwrap_or_best(block)?;
 		trace!(target: "rpc", "Querying storage at {:?} for key {}", block, HexDisplay::from(&key.0));
-		Ok(self.client.storage(&BlockId::Hash(block), &key)?)
+		Ok(self.client.storage(&BlockId::Hash(block), &key).map_err(client_err)?)
 	}
 
 	fn storage_hash(&self, key: StorageKey, block: Option<Block::Hash>) -> Result<Option<Block::Hash>> {
 		let block = self.unwrap_or_best(block)?;
 		trace!(target: "rpc", "Querying storage hash at {:?} for key {}", block, HexDisplay::from(&key.0));
-		Ok(self.client.storage_hash(&BlockId::Hash(block), &key)?)
+		Ok(self.client.storage_hash(&BlockId::Hash(block), &key).map_err(client_err)?)
 	}
 
 	fn storage_size(&self, key: StorageKey, block: Option<Block::Hash>) -> Result<Option<u64>> {
@@ -394,7 +289,10 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 	) -> Result<Option<StorageData>> {
 		let block = self.unwrap_or_best(block)?;
 		trace!(target: "rpc", "Querying child storage at {:?} for key {}", block, HexDisplay::from(&key.0));
-		Ok(self.client.child_storage(&BlockId::Hash(block), &child_storage_key, &key)?)
+		Ok(self.client
+		   .child_storage(&BlockId::Hash(block), &child_storage_key, &key)
+		   .map_err(client_err)?
+		)
 	}
 
 	fn child_storage_keys(
@@ -405,7 +303,10 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 	) -> Result<Vec<StorageKey>> {
 		let block = self.unwrap_or_best(block)?;
 		trace!(target: "rpc", "Querying child storage keys at {:?}", block);
-		Ok(self.client.child_storage_keys(&BlockId::Hash(block), &child_storage_key, &key_prefix)?)
+		Ok(self.client
+		   .child_storage_keys(&BlockId::Hash(block), &child_storage_key, &key_prefix)
+		   .map_err(client_err)?
+		)
 	}
 
 	fn child_storage_hash(
@@ -420,7 +321,10 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 			block,
 			HexDisplay::from(&key.0),
 		);
-		Ok(self.client.child_storage_hash(&BlockId::Hash(block), &child_storage_key, &key)?)
+		Ok(self.client
+		   .child_storage_hash(&BlockId::Hash(block), &child_storage_key, &key)
+		   .map_err(client_err)?
+		)
 	}
 
 	fn child_storage_size(
@@ -434,7 +338,11 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 
 	fn metadata(&self, block: Option<Block::Hash>) -> Result<Bytes> {
 		let block = self.unwrap_or_best(block)?;
-		self.client.runtime_api().metadata(&BlockId::Hash(block)).map(Into::into).map_err(Into::into)
+		self.client
+			.runtime_api()
+			.metadata(&BlockId::Hash(block))
+			.map(Into::into)
+			.map_err(client_err)
 	}
 
 	fn query_storage(
@@ -464,7 +372,7 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 		) {
 			Ok(stream) => stream,
 			Err(err) => {
-				let _ = subscriber.reject(error::Error::from(err).into());
+				let _ = subscriber.reject(client_err(err).into());
 				return;
 			},
 		};
@@ -508,7 +416,7 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 
 	fn runtime_version(&self, at: Option<Block::Hash>) -> Result<RuntimeVersion> {
 		let at = self.unwrap_or_best(at)?;
-		Ok(self.client.runtime_version_at(&BlockId::Hash(at))?)
+		Ok(self.client.runtime_version_at(&BlockId::Hash(at)).map_err(client_err)?)
 	}
 
 	fn subscribe_runtime_version(&self, _meta: Self::Metadata, subscriber: Subscriber<RuntimeVersion>) {
@@ -518,7 +426,7 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 		) {
 			Ok(stream) => stream,
 			Err(err) => {
-				let _ = subscriber.reject(error::Error::from(err).into());
+				let _ = subscriber.reject(client_err(err).into());
 				return;
 			}
 		};
@@ -535,7 +443,7 @@ impl<B, E, Block, RA> StateApi<Block::Hash> for State<B, E, Block, RA> where
 					let info = client.info();
 					let version = client
 						.runtime_version_at(&BlockId::hash(info.chain.best_hash))
-						.map_err(error::Error::from)
+						.map_err(client_err)
 						.map_err(Into::into);
 					if previous_version != version {
 						previous_version = version.clone();

substrate/core/rpc/src/state/tests.rs

@@ -90,7 +90,7 @@ fn should_call_contract() {
 
 	assert_matches!(
 		client.call("balanceOf".into(), Bytes(vec![1,2,3]), Some(genesis_hash).into()),
-		Err(Error::Client(client::error::Error::Execution(_)))
+		Err(Error::Client(_))
 	)
 }
 

substrate/core/rpc/src/system/mod.rs

@@ -16,62 +16,18 @@
 
 //! Substrate system API.
 
-pub mod error;
-pub mod helpers;
-
 #[cfg(test)]
 mod tests;
 
-use crate::helpers::Receiver;
 use futures03::{channel::{mpsc, oneshot}, compat::Compat};
-use jsonrpc_derive::rpc;
+use api::Receiver;
-use network;
 use sr_primitives::traits::{self, Header as HeaderT};
-
 use self::error::Result;
 
+pub use api::system::*;
 pub use self::helpers::{Properties, SystemInfo, Health, PeerInfo};
 pub use self::gen_client::Client as SystemClient;
 
-/// Substrate system RPC API
-#[rpc]
-pub trait SystemApi<Hash, Number> {
-	/// Get the node's implementation name. Plain old string.
-	#[rpc(name = "system_name")]
-	fn system_name(&self) -> Result<String>;
-
-	/// Get the node implementation's version. Should be a semver string.
-	#[rpc(name = "system_version")]
-	fn system_version(&self) -> Result<String>;
-
-	/// Get the chain's type. Given as a string identifier.
-	#[rpc(name = "system_chain")]
-	fn system_chain(&self) -> Result<String>;
-
-	/// Get a custom set of properties as a JSON object, defined in the chain spec.
-	#[rpc(name = "system_properties")]
-	fn system_properties(&self) -> Result<Properties>;
-
-	/// Return health status of the node.
-	///
-	/// Node is considered healthy if it is:
-	/// - connected to some peers (unless running in dev mode)
-	/// - not performing a major sync
-	#[rpc(name = "system_health", returns = "Health")]
-	fn system_health(&self) -> Receiver<Health>;
-
-	/// Returns currently connected peers
-	#[rpc(name = "system_peers", returns = "Vec<PeerInfo<Hash, Number>>")]
-	fn system_peers(&self) -> Receiver<Vec<PeerInfo<Hash, Number>>>;
-
-	/// Returns current state of the network.
-	///
-	/// **Warning**: This API is not stable.
-	// TODO: make this stable and move structs https://github.com/paritytech/substrate/issues/1890
-	#[rpc(name = "system_networkState", returns = "network::NetworkState")]
-	fn system_network_state(&self) -> Receiver<network::NetworkState>;
-}
-
 /// System API implementation
 pub struct System<B: traits::Block> {
 	info: SystemInfo,
@@ -85,7 +41,7 @@ pub enum Request<B: traits::Block> {
 	/// Must return information about the peers we are connected to.
 	Peers(oneshot::Sender<Vec<PeerInfo<B::Hash, <B::Header as HeaderT>::Number>>>),
 	/// Must return the state of the network.
-	NetworkState(oneshot::Sender<network::NetworkState>),
+	NetworkState(oneshot::Sender<rpc::Value>),
 }
 
 impl<B: traits::Block> System<B> {
@@ -133,7 +89,7 @@ impl<B: traits::Block> SystemApi<B::Hash, <B::Header as HeaderT>::Number> for Sy
 		Receiver(Compat::new(rx))
 	}
 
-	fn system_network_state(&self) -> Receiver<network::NetworkState> {
+	fn system_network_state(&self) -> Receiver<rpc::Value> {
 		let (tx, rx) = oneshot::channel();
 		let _ = self.send_back.unbounded_send(Request::NetworkState(tx));
 		Receiver(Compat::new(rx))

substrate/core/rpc/src/system/tests.rs

@@ -69,7 +69,7 @@ fn api<T: Into<Option<Status>>>(sync: T) -> System<Block> {
 					let _ = sender.send(peers);
 				}
 				Request::NetworkState(sender) => {
-					let _ = sender.send(network::NetworkState {
+					let _ = sender.send(serde_json::to_value(&network::NetworkState {
 						peer_id: String::new(),
 						listened_addresses: Default::default(),
 						external_addresses: Default::default(),
@@ -78,7 +78,7 @@ fn api<T: Into<Option<Status>>>(sync: T) -> System<Block> {
 						average_download_per_sec: 0,
 						average_upload_per_sec: 0,
 						peerset: serde_json::Value::Null,
-					});
+					}).unwrap());
 				}
 			};
 
@@ -206,8 +206,9 @@ fn system_peers() {
 
 #[test]
 fn system_network_state() {
+	let res = wait_receiver(api(None).system_network_state());
 	assert_eq!(
-		wait_receiver(api(None).system_network_state()),
+		serde_json::from_value::<network::NetworkState>(res).unwrap(),
 		network::NetworkState {
 			peer_id: String::new(),
 			listened_addresses: Default::default(),

substrate/core/service/src/lib.rs

@@ -725,7 +725,9 @@ fn build_network_future<
 					).collect());
 				}
 				rpc::system::Request::NetworkState(sender) => {
-					let _ = sender.send(network.network_state());
+					if let Some(network_state) = serde_json::to_value(&network.network_state()).ok() {
+						let _ = sender.send(network_state);
+					}
 				}
 			};
 		}