proc_macro.rs

// Copyright 2019-2021 Parity Technologies (UK) Ltd.
//
// Permission is hereby granted, free of charge, to any
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// the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following
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//
// The above copyright notice and this permission notice
// shall be included in all copies or substantial portions
// of the Software.
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
// ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
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use jsonrpsee::{
	proc_macros::rpc,
	types::{async_trait, error::Error},
	ws_client::WsClientBuilder,
	ws_server::{RpcModule, SubscriptionSink, WsServerBuilder},
};
use std::net::SocketAddr;

#[rpc(server, client, namespace = "state")]
pub trait Rpc {
	/// Async method call example.
	#[method(name = "getPairs")]
	async fn storage_pairs(&self, prefix: usize, hash: Option<u128>) -> Result<Vec<usize>, Error>;

	/// Subscription that take `Option<Vec<u8>>` as input and produces output `Vec<usize>`.
	#[subscription(name = "subscribeStorage", unsub = "unsubscribeStorage", item = Vec<usize>)]
	fn subscribe_storage(&self, keys: Option<Vec<u8>>);
}

pub struct RpcServerImpl;

#[async_trait]
impl RpcServer for RpcServerImpl {
	async fn storage_pairs(&self, _prefix: usize, _hash: Option<u128>) -> Result<Vec<usize>, Error> {
		Ok(vec![1, 2, 3, 4])
	}

	fn subscribe_storage(&self, mut sink: SubscriptionSink, keys: Option<Vec<u8>>) {
		sink.send(&keys.unwrap_or_default()).unwrap();
	}
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
	env_logger::init();

	let server_addr = run_server().await?;
	let url = format!("ws://{}", server_addr);

	let client = WsClientBuilder::default().build(&url).await?;
	assert_eq!(client.storage_pairs(10, None).await.unwrap(), vec![1, 2, 3, 4]);

	let mut sub = client.subscribe_storage(None).await.unwrap();
	assert_eq!(Some(vec![]), sub.next().await.unwrap());

	Ok(())
}

async fn run_server() -> anyhow::Result<SocketAddr> {
	let server = WsServerBuilder::default().build("127.0.0.1:0").await?;
	let mut module = RpcModule::new(());
	module.register_method("state_getPairs", |_, _| Ok(vec![1, 2, 3]))?;

	let addr = server.local_addr()?;
	tokio::spawn(async move { server.start(RpcServerImpl.into_rpc()).await });
	Ok(addr)
}