rpc/jsonrpc: Implement requests over Unix sockets.

src/rpc/jsonrpc.rs

@@ -1,4 +1,5 @@
 use std::net::{TcpStream, ToSocketAddrs};
+use std::os::unix::net::UnixStream;
 use std::str;
 
 use async_std::io::{ReadExt, WriteExt};
@@ -186,3 +187,16 @@ pub async fn send_raw_request(url: &str, data: Value) -> Result<JsonResult, Erro
     let reply: JsonResult = serde_json::from_slice(&buf[0..bytes_read])?;
     Ok(reply)
 }
+
+pub async fn send_unix_request(path: &str, data: Value) -> Result<JsonResult, Error> {
+    let mut buf = [0; 2048];
+    let bytes_read: usize;
+    let data_str = serde_json::to_string(&data)?;
+
+    let mut stream = Async::<UnixStream>::connect(path).await?;
+    stream.write_all(&data_str.as_bytes()).await?;
+    bytes_read = stream.read(&mut buf[..]).await?;
+
+    let reply: JsonResult = serde_json::from_slice(&buf[0..bytes_read])?;
+    Ok(reply)
+}