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#![deny(missing_docs)]
use jsonrpc_core::futures::channel::{mpsc, oneshot};
use jsonrpc_core::futures::{
self,
task::{Context, Poll},
Future, Stream, StreamExt,
};
use jsonrpc_core::{Error, Params};
use serde::de::DeserializeOwned;
use serde::Serialize;
use serde_json::Value;
use std::marker::PhantomData;
use std::pin::Pin;
pub mod transports;
#[cfg(test)]
mod logger;
#[derive(Debug, derive_more::Display)]
pub enum RpcError {
#[display(fmt = "Server returned rpc error {}", _0)]
JsonRpcError(Error),
#[display(fmt = "Failed to parse server response as {}: {}", _0, _1)]
ParseError(String, Box<dyn std::error::Error + Send>),
#[display(fmt = "Request timed out")]
Timeout,
#[display(fmt = "Client error: {}", _0)]
Client(String),
#[display(fmt = "{}", _0)]
Other(Box<dyn std::error::Error + Send>),
}
impl std::error::Error for RpcError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
match *self {
Self::JsonRpcError(ref e) => Some(e),
Self::ParseError(_, ref e) => Some(&**e),
Self::Other(ref e) => Some(&**e),
_ => None,
}
}
}
impl From<Error> for RpcError {
fn from(error: Error) -> Self {
RpcError::JsonRpcError(error)
}
}
pub type RpcResult<T> = Result<T, RpcError>;
struct CallMessage {
method: String,
params: Params,
sender: oneshot::Sender<RpcResult<Value>>,
}
struct NotifyMessage {
method: String,
params: Params,
}
struct Subscription {
subscribe: String,
subscribe_params: Params,
notification: String,
unsubscribe: String,
}
struct SubscribeMessage {
subscription: Subscription,
sender: mpsc::UnboundedSender<RpcResult<Value>>,
}
enum RpcMessage {
Call(CallMessage),
Notify(NotifyMessage),
Subscribe(SubscribeMessage),
}
impl From<CallMessage> for RpcMessage {
fn from(msg: CallMessage) -> Self {
RpcMessage::Call(msg)
}
}
impl From<NotifyMessage> for RpcMessage {
fn from(msg: NotifyMessage) -> Self {
RpcMessage::Notify(msg)
}
}
impl From<SubscribeMessage> for RpcMessage {
fn from(msg: SubscribeMessage) -> Self {
RpcMessage::Subscribe(msg)
}
}
#[derive(Clone)]
pub struct RpcChannel(mpsc::UnboundedSender<RpcMessage>);
impl RpcChannel {
fn send(&self, msg: RpcMessage) -> Result<(), mpsc::TrySendError<RpcMessage>> {
self.0.unbounded_send(msg)
}
}
impl From<mpsc::UnboundedSender<RpcMessage>> for RpcChannel {
fn from(sender: mpsc::UnboundedSender<RpcMessage>) -> Self {
RpcChannel(sender)
}
}
pub type RpcFuture = oneshot::Receiver<Result<Value, RpcError>>;
pub type SubscriptionStream = mpsc::UnboundedReceiver<Result<Value, RpcError>>;
pub struct TypedSubscriptionStream<T> {
_marker: PhantomData<T>,
returns: &'static str,
stream: SubscriptionStream,
}
impl<T> TypedSubscriptionStream<T> {
pub fn new(stream: SubscriptionStream, returns: &'static str) -> Self {
TypedSubscriptionStream {
_marker: PhantomData,
returns,
stream,
}
}
}
impl<T: DeserializeOwned + Unpin + 'static> Stream for TypedSubscriptionStream<T> {
type Item = RpcResult<T>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
let result = futures::ready!(self.stream.poll_next_unpin(cx));
match result {
Some(Ok(value)) => Some(
serde_json::from_value::<T>(value)
.map_err(|error| RpcError::ParseError(self.returns.into(), Box::new(error))),
),
None => None,
Some(Err(err)) => Some(Err(err)),
}
.into()
}
}
#[derive(Clone)]
pub struct RawClient(RpcChannel);
impl From<RpcChannel> for RawClient {
fn from(channel: RpcChannel) -> Self {
RawClient(channel)
}
}
impl RawClient {
pub fn call_method(&self, method: &str, params: Params) -> impl Future<Output = RpcResult<Value>> {
let (sender, receiver) = oneshot::channel();
let msg = CallMessage {
method: method.into(),
params,
sender,
};
let result = self.0.send(msg.into());
async move {
let () = result.map_err(|e| RpcError::Other(Box::new(e)))?;
receiver.await.map_err(|e| RpcError::Other(Box::new(e)))?
}
}
pub fn notify(&self, method: &str, params: Params) -> RpcResult<()> {
let msg = NotifyMessage {
method: method.into(),
params,
};
match self.0.send(msg.into()) {
Ok(()) => Ok(()),
Err(error) => Err(RpcError::Other(Box::new(error))),
}
}
pub fn subscribe(
&self,
subscribe: &str,
subscribe_params: Params,
notification: &str,
unsubscribe: &str,
) -> RpcResult<SubscriptionStream> {
let (sender, receiver) = mpsc::unbounded();
let msg = SubscribeMessage {
subscription: Subscription {
subscribe: subscribe.into(),
subscribe_params,
notification: notification.into(),
unsubscribe: unsubscribe.into(),
},
sender,
};
self.0
.send(msg.into())
.map(|()| receiver)
.map_err(|e| RpcError::Other(Box::new(e)))
}
}
#[derive(Clone)]
pub struct TypedClient(RawClient);
impl From<RpcChannel> for TypedClient {
fn from(channel: RpcChannel) -> Self {
TypedClient(channel.into())
}
}
impl TypedClient {
pub fn new(raw_cli: RawClient) -> Self {
TypedClient(raw_cli)
}
pub fn call_method<T: Serialize, R: DeserializeOwned>(
&self,
method: &str,
returns: &str,
args: T,
) -> impl Future<Output = RpcResult<R>> {
let returns = returns.to_owned();
let args =
serde_json::to_value(args).expect("Only types with infallible serialisation can be used for JSON-RPC");
let params = match args {
Value::Array(vec) => Ok(Params::Array(vec)),
Value::Null => Ok(Params::None),
Value::Object(map) => Ok(Params::Map(map)),
_ => Err(RpcError::Client(
"RPC params should serialize to a JSON array, JSON object or null".into(),
)),
};
let result = params.map(|params| self.0.call_method(method, params));
async move {
let value: Value = result?.await?;
log::debug!("response: {:?}", value);
serde_json::from_value::<R>(value).map_err(|error| RpcError::ParseError(returns, Box::new(error)))
}
}
pub fn notify<T: Serialize>(&self, method: &str, args: T) -> RpcResult<()> {
let args =
serde_json::to_value(args).expect("Only types with infallible serialisation can be used for JSON-RPC");
let params = match args {
Value::Array(vec) => Params::Array(vec),
Value::Null => Params::None,
_ => {
return Err(RpcError::Client(
"RPC params should serialize to a JSON array, or null".into(),
))
}
};
self.0.notify(method, params)
}
pub fn subscribe<T: Serialize, R: DeserializeOwned + 'static>(
&self,
subscribe: &str,
subscribe_params: T,
topic: &str,
unsubscribe: &str,
returns: &'static str,
) -> RpcResult<TypedSubscriptionStream<R>> {
let args = serde_json::to_value(subscribe_params)
.expect("Only types with infallible serialisation can be used for JSON-RPC");
let params = match args {
Value::Array(vec) => Params::Array(vec),
Value::Null => Params::None,
_ => {
return Err(RpcError::Client(
"RPC params should serialize to a JSON array, or null".into(),
))
}
};
self.0
.subscribe(subscribe, params, topic, unsubscribe)
.map(move |stream| TypedSubscriptionStream::new(stream, returns))
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::transports::local;
use crate::{RpcChannel, TypedClient};
use jsonrpc_core::futures::{future, FutureExt};
use jsonrpc_core::{self as core, IoHandler};
use jsonrpc_pubsub::{PubSubHandler, Subscriber, SubscriptionId};
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
#[derive(Clone)]
struct AddClient(TypedClient);
impl From<RpcChannel> for AddClient {
fn from(channel: RpcChannel) -> Self {
AddClient(channel.into())
}
}
impl AddClient {
fn add(&self, a: u64, b: u64) -> impl Future<Output = RpcResult<u64>> {
self.0.call_method("add", "u64", (a, b))
}
fn completed(&self, success: bool) -> RpcResult<()> {
self.0.notify("completed", (success,))
}
}
#[test]
fn test_client_terminates() {
crate::logger::init_log();
let mut handler = IoHandler::new();
handler.add_sync_method("add", |params: Params| {
let (a, b) = params.parse::<(u64, u64)>()?;
let res = a + b;
Ok(jsonrpc_core::to_value(res).unwrap())
});
let (tx, rx) = std::sync::mpsc::channel();
let (client, rpc_client) = local::connect::<AddClient, _, _>(handler);
let fut = async move {
let res = client.add(3, 4).await?;
let res = client.add(res, 5).await?;
assert_eq!(res, 12);
tx.send(()).unwrap();
Ok(()) as RpcResult<_>
};
let pool = futures::executor::ThreadPool::builder().pool_size(1).create().unwrap();
pool.spawn_ok(rpc_client.map(|x| x.unwrap()));
pool.spawn_ok(fut.map(|x| x.unwrap()));
rx.recv().unwrap()
}
#[test]
fn should_send_notification() {
crate::logger::init_log();
let (tx, rx) = std::sync::mpsc::sync_channel(1);
let mut handler = IoHandler::new();
handler.add_notification("completed", move |params: Params| {
let (success,) = params.parse::<(bool,)>().expect("expected to receive one boolean");
assert_eq!(success, true);
tx.send(()).unwrap();
});
let (client, rpc_client) = local::connect::<AddClient, _, _>(handler);
client.completed(true).unwrap();
let pool = futures::executor::ThreadPool::builder().pool_size(1).create().unwrap();
pool.spawn_ok(rpc_client.map(|x| x.unwrap()));
rx.recv().unwrap()
}
#[test]
fn should_handle_subscription() {
crate::logger::init_log();
let (finish, finished) = std::sync::mpsc::sync_channel(1);
let mut handler = PubSubHandler::<local::LocalMeta, _>::default();
let called = Arc::new(AtomicBool::new(false));
let called2 = called.clone();
handler.add_subscription(
"hello",
("subscribe_hello", move |params, _meta, subscriber: Subscriber| {
assert_eq!(params, core::Params::None);
let sink = subscriber
.assign_id(SubscriptionId::Number(5))
.expect("assigned subscription id");
let finish = finish.clone();
std::thread::spawn(move || {
for i in 0..3 {
std::thread::sleep(std::time::Duration::from_millis(100));
let value = serde_json::json!({
"subscription": 5,
"result": vec![i],
});
let _ = sink.notify(serde_json::from_value(value).unwrap());
}
finish.send(()).unwrap();
});
}),
("unsubscribe_hello", move |id, _meta| {
called2.store(true, Ordering::SeqCst);
assert_eq!(id, SubscriptionId::Number(5));
future::ready(Ok(core::Value::Bool(true)))
}),
);
let (tx, rx) = std::sync::mpsc::channel();
let (client, rpc_client) = local::connect_with_pubsub::<TypedClient, _>(handler);
let received = Arc::new(std::sync::Mutex::new(vec![]));
let r2 = received.clone();
let fut = async move {
let mut stream =
client.subscribe::<_, (u32,)>("subscribe_hello", (), "hello", "unsubscribe_hello", "u32")?;
let result = stream.next().await;
r2.lock().unwrap().push(result.expect("Expected at least one item."));
tx.send(()).unwrap();
Ok(()) as RpcResult<_>
};
let pool = futures::executor::ThreadPool::builder().pool_size(1).create().unwrap();
pool.spawn_ok(rpc_client.map(|_| ()));
pool.spawn_ok(fut.map(|x| x.unwrap()));
rx.recv().unwrap();
assert!(
!received.lock().unwrap().is_empty(),
"Expected at least one received item."
);
finished.recv().unwrap();
assert_eq!(called.load(Ordering::SeqCst), true, "Unsubscribe not called.");
}
}