Performance: Avoid converting responses to serde_json::Value

core-client/transports/src/transports/http.rs

@@ -139,12 +139,16 @@ mod tests {
 	}
 
 	fn io() -> IoHandler {
+		use jsonrpc_core::Result;
+
 		let mut io = IoHandler::default();
 		io.add_sync_method("hello", |params: Params| match params.parse::<(String,)>() {
 			Ok((msg,)) => Ok(Value::String(format!("hello {}", msg))),
 			_ => Ok(Value::String("world".into())),
 		});
-		io.add_sync_method("fail", |_: Params| Err(Error::new(ErrorCode::ServerError(-34))));
+		io.add_sync_method("fail", |_: Params| -> Result<i64> {
+			Err(Error::new(ErrorCode::ServerError(-34)))
+		});
 		io.add_notification("notify", |params: Params| {
 			let (value,) = params.parse::<(u64,)>().expect("expected one u64 as param");
 			assert_eq!(value, 12);

core/examples/middlewares.rs

@@ -17,7 +17,7 @@ impl Middleware<Meta> for MyMiddleware {
 	fn on_request<F, X>(&self, request: Request, meta: Meta, next: F) -> Either<Self::Future, X>
 	where
 		F: FnOnce(Request, Meta) -> X + Send,
-		X: Future<Output = Option<Response>> + Send + 'static,
+		X: Future<Output = Option<SerializedResponse>> + Send + 'static,
 	{
 		let start = Instant::now();
 		let request_number = self.0.fetch_add(1, atomic::Ordering::SeqCst);

core/src/calls.rs

@@ -1,5 +1,7 @@
-use crate::types::{Error, Params, Value};
+use crate::types::{Error, Id, Params, SerializedOutput, Value, Version};
 use crate::BoxFuture;
+use futures_util::{self, future, FutureExt};
+use serde::Serialize;
 use std::fmt;
 use std::future::Future;
 use std::sync::Arc;
@@ -30,23 +32,23 @@ impl<T, E> WrapFuture<T, E> for BoxFuture<Result<T, E>> {
 }
 
 /// A synchronous or asynchronous method.
-pub trait RpcMethodSync: Send + Sync + 'static {
+pub trait RpcMethodSync<R = Value>: Send + Sync + 'static {
 	/// Call method
-	fn call(&self, params: Params) -> BoxFuture<crate::Result<Value>>;
+	fn call(&self, params: Params) -> BoxFuture<crate::Result<R>>;
 }
 
 /// Asynchronous Method
-pub trait RpcMethodSimple: Send + Sync + 'static {
+pub trait RpcMethodSimple<R = Value>: Send + Sync + 'static {
 	/// Output future
-	type Out: Future<Output = Result<Value, Error>> + Send;
+	type Out: Future<Output = Result<R, Error>> + Send;
 	/// Call method
 	fn call(&self, params: Params) -> Self::Out;
 }
 
 /// Asynchronous Method with Metadata
-pub trait RpcMethod<T: Metadata>: Send + Sync + 'static {
+pub trait RpcMethod<T: Metadata, R = Value>: Send + Sync + 'static {
 	/// Call method
-	fn call(&self, params: Params, meta: T) -> BoxFuture<crate::Result<Value>>;
+	fn call(&self, params: Params, meta: T) -> BoxFuture<crate::Result<R>>;
 }
 
 /// Notification
@@ -61,11 +63,24 @@ pub trait RpcNotification<T: Metadata>: Send + Sync + 'static {
 	fn execute(&self, params: Params, meta: T);
 }
 
+pub trait RpcMethodWithSerializedOutput<T: Metadata>: Send + Sync + 'static {
+	fn call(&self, params: Params, meta: T, jsonrpc: Option<Version>, id: Id) -> BoxFuture<Option<SerializedOutput>>;
+}
+
+pub fn rpc_wrap<T: Metadata, R: Serialize + Send + 'static, F: RpcMethod<T, R>>(
+	f: F,
+) -> Arc<dyn RpcMethodWithSerializedOutput<T>> {
+	Arc::new(move |params: Params, meta: T, jsonrpc: Option<Version>, id: Id| {
+		let result = f.call(params, meta);
+		result.then(move |r| future::ready(Some(SerializedOutput::from(r, id, jsonrpc))))
+	})
+}
+
 /// Possible Remote Procedures with Metadata
 #[derive(Clone)]
 pub enum RemoteProcedure<T: Metadata> {
 	/// A method call
-	Method(Arc<dyn RpcMethod<T>>),
+	Method(Arc<dyn RpcMethodWithSerializedOutput<T>>),
 	/// A notification
 	Notification(Arc<dyn RpcNotification<T>>),
 	/// An alias to other method,
@@ -83,23 +98,23 @@ impl<T: Metadata> fmt::Debug for RemoteProcedure<T> {
 	}
 }
 
-impl<F: Send + Sync + 'static, X: Send + 'static> RpcMethodSimple for F
+impl<F: Send + Sync + 'static, X: Send + 'static, R> RpcMethodSimple<R> for F
 where
 	F: Fn(Params) -> X,
-	X: Future<Output = Result<Value, Error>>,
+	X: Future<Output = Result<R, Error>>,
 {
 	type Out = X;
 	fn call(&self, params: Params) -> Self::Out {
 		self(params)
 	}
 }
 
-impl<F: Send + Sync + 'static, X: Send + 'static> RpcMethodSync for F
+impl<F: Send + Sync + 'static, X: Send + 'static, R> RpcMethodSync<R> for F
 where
 	F: Fn(Params) -> X,
-	X: WrapFuture<Value, Error>,
+	X: WrapFuture<R, Error>,
 {
-	fn call(&self, params: Params) -> BoxFuture<crate::Result<Value>> {
+	fn call(&self, params: Params) -> BoxFuture<crate::Result<R>> {
 		self(params).into_future()
 	}
 }
@@ -113,13 +128,13 @@ where
 	}
 }
 
-impl<F: Send + Sync + 'static, X: Send + 'static, T> RpcMethod<T> for F
+impl<F: Send + Sync + 'static, X: Send + 'static, T, R> RpcMethod<T, R> for F
 where
 	T: Metadata,
 	F: Fn(Params, T) -> X,
-	X: Future<Output = Result<Value, Error>>,
+	X: Future<Output = Result<R, Error>>,
 {
-	fn call(&self, params: Params, meta: T) -> BoxFuture<crate::Result<Value>> {
+	fn call(&self, params: Params, meta: T) -> BoxFuture<crate::Result<R>> {
 		Box::pin(self(params, meta))
 	}
 }
@@ -133,3 +148,14 @@ where
 		self(params, meta)
 	}
 }
+
+impl<F: Send + Sync + 'static, X: Send + 'static, T> RpcMethodWithSerializedOutput<T> for F
+where
+	T: Metadata,
+	F: Fn(Params, T, Option<Version>, Id) -> X,
+	X: Future<Output = Option<SerializedOutput>>,
+{
+	fn call(&self, params: Params, meta: T, jsonrpc: Option<Version>, id: Id) -> BoxFuture<Option<SerializedOutput>> {
+		Box::pin(self(params, meta, jsonrpc, id))
+	}
+}

core/src/delegates.rs

@@ -1,27 +1,28 @@
 //! Delegate rpc calls
 
+use serde::Serialize;
 use std::collections::HashMap;
 use std::future::Future;
 use std::sync::Arc;
 
-use crate::calls::{Metadata, RemoteProcedure, RpcMethod, RpcNotification};
-use crate::types::{Error, Params, Value};
+use crate::calls::{rpc_wrap, Metadata, RemoteProcedure, RpcMethod, RpcNotification};
+use crate::types::{Error, Params};
 use crate::BoxFuture;
 
 struct DelegateAsyncMethod<T, F> {
 	delegate: Arc<T>,
 	closure: F,
 }
 
-impl<T, M, F, I> RpcMethod<M> for DelegateAsyncMethod<T, F>
+impl<T, M, F, I, R> RpcMethod<M, R> for DelegateAsyncMethod<T, F>
 where
 	M: Metadata,
 	F: Fn(&T, Params) -> I,
-	I: Future<Output = Result<Value, Error>> + Send + 'static,
+	I: Future<Output = Result<R, Error>> + Send + 'static,
 	T: Send + Sync + 'static,
 	F: Send + Sync + 'static,
 {
-	fn call(&self, params: Params, _meta: M) -> BoxFuture<crate::Result<Value>> {
+	fn call(&self, params: Params, _meta: M) -> BoxFuture<crate::Result<R>> {
 		let closure = &self.closure;
 		Box::pin(closure(&self.delegate, params))
 	}
@@ -32,15 +33,15 @@ struct DelegateMethodWithMeta<T, F> {
 	closure: F,
 }
 
-impl<T, M, F, I> RpcMethod<M> for DelegateMethodWithMeta<T, F>
+impl<T, M, F, I, R> RpcMethod<M, R> for DelegateMethodWithMeta<T, F>
 where
 	M: Metadata,
 	F: Fn(&T, Params, M) -> I,
-	I: Future<Output = Result<Value, Error>> + Send + 'static,
+	I: Future<Output = Result<R, Error>> + Send + 'static,
 	T: Send + Sync + 'static,
 	F: Send + Sync + 'static,
 {
-	fn call(&self, params: Params, meta: M) -> BoxFuture<crate::Result<Value>> {
+	fn call(&self, params: Params, meta: M) -> BoxFuture<crate::Result<R>> {
 		let closure = &self.closure;
 		Box::pin(closure(&self.delegate, params, meta))
 	}
@@ -112,31 +113,33 @@ where
 	}
 
 	/// Adds async method to the delegate.
-	pub fn add_method<F, I>(&mut self, name: &str, method: F)
+	pub fn add_method<F, I, R>(&mut self, name: &str, method: F)
 	where
 		F: Fn(&T, Params) -> I,
-		I: Future<Output = Result<Value, Error>> + Send + 'static,
+		I: Future<Output = Result<R, Error>> + Send + 'static,
 		F: Send + Sync + 'static,
+		R: Serialize + Send + 'static,
 	{
 		self.methods.insert(
 			name.into(),
-			RemoteProcedure::Method(Arc::new(DelegateAsyncMethod {
+			RemoteProcedure::Method(rpc_wrap(DelegateAsyncMethod {
 				delegate: self.delegate.clone(),
 				closure: method,
 			})),
 		);
 	}
 
 	/// Adds async method with metadata to the delegate.
-	pub fn add_method_with_meta<F, I>(&mut self, name: &str, method: F)
+	pub fn add_method_with_meta<F, I, R>(&mut self, name: &str, method: F)
 	where
 		F: Fn(&T, Params, M) -> I,
-		I: Future<Output = Result<Value, Error>> + Send + 'static,
+		I: Future<Output = Result<R, Error>> + Send + 'static,
 		F: Send + Sync + 'static,
+		R: Serialize + Send + 'static,
 	{
 		self.methods.insert(
 			name.into(),
-			RemoteProcedure::Method(Arc::new(DelegateMethodWithMeta {
+			RemoteProcedure::Method(rpc_wrap(DelegateMethodWithMeta {
 				delegate: self.delegate.clone(),
 				closure: method,
 			})),