jsonrpc_derive/

lib.rs

//! High level, typed wrapper for `jsonrpc_core`.
//!
//! Enables creation of "Service" objects grouping a set of RPC methods together in a typed manner.
//!
//! Example
//!
//! ```
//! use jsonrpc_core::{IoHandler, Result, BoxFuture};
//! use jsonrpc_core::futures::future;
//! use jsonrpc_derive::rpc;
//!
//! #[rpc(server)]
//! pub trait Rpc {
//!     #[rpc(name = "protocolVersion")]
//!     fn protocol_version(&self) -> Result<String>;
//!
//!     #[rpc(name = "add")]
//!     fn add(&self, a: u64, b: u64) -> Result<u64>;
//!
//!     #[rpc(name = "callAsync")]
//!     fn call(&self, a: u64) -> BoxFuture<Result<String>>;
//! }
//!
//! 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) -> BoxFuture<Result<String>> {
//!         Box::pin(future::ready(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::sync::{atomic, Arc, RwLock};
//! use std::collections::HashMap;
//!
//! use jsonrpc_core::{Error, ErrorCode, Result};
//! use jsonrpc_derive::rpc;
//! use 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>, param: 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,
//!          })
//!         }
//!     }
//! }
//!
//! fn main() {
//!   let mut io = jsonrpc_core::MetaIoHandler::default();
//!   io.extend_with(RpcImpl::default().to_delegate());
//!
//!   let server_builder = jsonrpc_tcp_server::ServerBuilder::with_meta_extractor(
//!     io,
//!     |request: &jsonrpc_tcp_server::RequestContext| Arc::new(Session::new(request.sender.clone()))
//!   );
//!   let server = server_builder
//!     .start(&"127.0.0.1:3030".parse().unwrap())
//!     .expect("Unable to start TCP server");
//!
//!   // The server spawns a separate thread. Dropping the `server` handle causes it to close.
//!   // Uncomment the line below to keep the server running in your example.
//!   // server.wait();
//! }
//! ```
//!
//! Client Example
//!
//! ```
//! use jsonrpc_core_client::transports::local;
//! use jsonrpc_core::futures::{self, future};
//! use jsonrpc_core::{IoHandler, Result, BoxFuture};
//! use jsonrpc_derive::rpc;
//!
//! /// Rpc trait
//! #[rpc]
//! pub trait Rpc {
//!     /// Returns a protocol version
//!     #[rpc(name = "protocolVersion")]
//!     fn protocol_version(&self) -> Result<String>;
//!
//!     /// Adds two numbers and returns a result
//!     #[rpc(name = "add", alias("callAsyncMetaAlias"))]
//!     fn add(&self, a: u64, b: u64) -> Result<u64>;
//!
//!     /// Performs asynchronous operation
//!     #[rpc(name = "callAsync")]
//!     fn call(&self, a: u64) -> BoxFuture<Result<String>>;
//! }
//!
//! 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) -> BoxFuture<Result<String>> {
//!         Box::pin(future::ready(Ok("OK".to_owned())))
//!    }
//! }
//!
//! fn main() {
//!     let exec = futures::executor::ThreadPool::new().unwrap();
//!     exec.spawn_ok(run())
//! }
//! async fn run() {
//!    let mut io = IoHandler::new();
//!    io.extend_with(RpcImpl.to_delegate());
//!
//!    let (client, server) = local::connect::<RpcClient, _, _>(io);
//!    let res = client.add(5, 6).await.unwrap();
//!    println!("5 + 6 = {}", res);
//!    server.await.unwrap()
//! }
//!
//! ```

#![recursion_limit = "256"]
#![warn(missing_docs)]

extern crate proc_macro;

use proc_macro::TokenStream;
use syn::parse_macro_input;

mod options;
mod params_style;
mod rpc_attr;
mod rpc_trait;
mod to_client;
mod to_delegate;

/// Apply `#[rpc]` to a trait, and a `to_delegate` method is generated which
/// wires up methods decorated with `#[rpc]` or `#[pubsub]` attributes.
/// Attach the delegate to an `IoHandler` and the methods are now callable
/// via JSON-RPC.
#[proc_macro_attribute]
pub fn rpc(args: TokenStream, input: TokenStream) -> TokenStream {
	let input_toks = parse_macro_input!(input as syn::Item);
	let args = syn::parse_macro_input!(args as syn::AttributeArgs);

	let options = match options::DeriveOptions::try_from(args) {
		Ok(options) => options,
		Err(error) => return error.to_compile_error().into(),
	};

	match rpc_trait::rpc_impl(input_toks, &options) {
		Ok(output) => output.into(),
		Err(err) => err.to_compile_error().into(),
	}
}