Implement JSON-RPC client PoC

client/src/tcp.rs

@@ -0,0 +1,29 @@
+use jsonrpc_client_transports::{transports::duplex, RpcChannel, RpcError};
+use jsonrpc_core::futures_util::{SinkExt, StreamExt, TryStreamExt};
+use jsonrpc_server_utils::{codecs::StreamCodec, tokio_util::codec::Decoder};
+use tokio::net::{TcpStream, ToSocketAddrs};
+
+/// Connect to a JSON-RPC TCP server.
+pub async fn connect<S: ToSocketAddrs, Client: From<RpcChannel>>(
+    socket: S,
+) -> Result<Client, RpcError> {
+    let connection = TcpStream::connect(socket)
+        .await
+        .map_err(|e| RpcError::Other(Box::new(e)))?;
+    let (sink, stream) = StreamCodec::stream_incoming().framed(connection).split();
+    let sink = sink.sink_map_err(|e| RpcError::Other(Box::new(e)));
+    let stream = stream.map_err(|e| log::error!("TCP stream error: {}", e));
+
+    let (client, sender) = duplex(
+        Box::pin(sink),
+        Box::pin(
+            stream
+                .take_while(|x| std::future::ready(x.is_ok()))
+                .map(|x| x.expect("Stream is closed upon first error.")),
+        ),
+    );
+
+    tokio::spawn(client);
+
+    Ok(sender.into())
+}