#json-rpc #typed #susy #high-level #wrapper #derive #methods

macro susy-jsonrpc-derive

High level, typed wrapper for susy-jsonrpc-core

1 stable release

10.1.0 Mar 24, 2019
10.0.2 Mar 25, 2019

#8 in #susy

25 downloads per month
Used in susy-jsonrpc-test

MIT license

32KB
767 lines

High level, typed wrapper for susy_jsonrpc_core.

Enables creation of "Service" objects grouping a set of RPC methods together in a typed manner.

Example

use susy_jsonrpc_derive::rpc;
use susy_jsonrpc_core::{IoHandler, Error, Result};
use susy_jsonrpc_core::futures::future::{self, FutureResult};

#[rpc]
pub trait Rpc {
	#[rpc(name = "protocolVersion")]
	fn protocol_version(&self) -> Result<String>;

	#[rpc(name = "add")]
	fn add(&self, _: u64, _: u64) -> Result<u64>;

	#[rpc(name = "callAsync")]
	fn call(&self, _: u64) -> FutureResult<String, Error>;
}

struct RpcImpl;
impl Rpc for RpcImpl {
	fn protocol_version(&self) -> Result<String> {
		Ok("version1".into())
	}

	fn add(&self, a: u64, b: u64) -> Result<u64> {
		Ok(a + b)
	}

	fn call(&self, _: u64) -> FutureResult<String, Error> {
		future::ok("OK".to_owned()).into()
	}
}

fn main() {
     let mut io = IoHandler::new();
     let rpc = RpcImpl;

     io.extend_with(rpc.to_delegate());
}

Pub/Sub Example

Each subscription must have subscribe and unsubscribe methods. They can have any name but must be annotated with subscribe or unsubscribe and have a matching unique subscription name.

use std::thread;
use std::sync::{atomic, Arc, RwLock};
use std::collections::HashMap;

use susy_jsonrpc_core::{Error, ErrorCode, Result};
use susy_jsonrpc_core::futures::Future;
use susy_jsonrpc_derive::rpc;
use susy_jsonrpc_pubsub::{Session, PubSubHandler, SubscriptionId, typed::{Subscriber, Sink}};

#[rpc]
pub trait Rpc {
   	type Metadata;

   	/// Hello subscription
   	#[pubsub(
		subscription = "hello",
		subscribe,
		name = "hello_subscribe",
		alias("hello_sub")
	)]
   	fn subscribe(&self, _: Self::Metadata, _: Subscriber<String>, _: u64);

   	/// Unsubscribe from hello subscription.
   	#[pubsub(
		subscription = "hello",
		unsubscribe,
		name = "hello_unsubscribe"
	)]
   	fn unsubscribe(&self, _: Option<Self::Metadata>, _: SubscriptionId) -> Result<bool>;
}


#[derive(Default)]
struct RpcImpl {
	uid: atomic::AtomicUsize,
	active: Arc<RwLock<HashMap<SubscriptionId, Sink<String>>>>,
}
impl Rpc for RpcImpl {
	type Metadata = Arc<Session>;

	fn subscribe(&self, _meta: Self::Metadata, subscriber: Subscriber<String>, param: u64) {
		if param != 10 {
			subscriber.reject(Error {
				code: ErrorCode::InvalidParams,
				message: "Rejecting subscription - invalid parameters provided.".into(),
				data: None,
			}).unwrap();
			return;
		}

		let id = self.uid.fetch_add(1, atomic::Ordering::SeqCst);
		let sub_id = SubscriptionId::Number(id as u64);
		let sink = subscriber.assign_id(sub_id.clone()).unwrap();
		self.active.write().unwrap().insert(sub_id, sink);
	}

	fn unsubscribe(&self, _meta: Option<Self::Metadata>, id: SubscriptionId) -> Result<bool> {
		let removed = self.active.write().unwrap().remove(&id);
		if removed.is_some() {
			Ok(true)
		} else {
			Err(Error {
				code: ErrorCode::InvalidParams,
				message: "Invalid subscription.".into(),
				data: None,
			})
		}
	}
}

Dependencies

~2MB
~53K SLoC