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|
use std::{
thread,
io::{
stdout, stdin,
BufRead, Write,
},
};
use serde_json::{Value, from_str, to_string};
use crossbeam_channel::{Receiver, Sender, bounded};
use Result;
#[derive(Debug, Serialize, Deserialize)]
#[serde(untagged)]
pub enum RawMsg {
Request(RawRequest),
Notification(RawNotification),
Response(RawResponse),
}
#[derive(Debug, Serialize, Deserialize)]
pub struct RawRequest {
pub id: u64,
pub method: String,
pub params: Value,
}
#[derive(Debug, Serialize, Deserialize)]
pub struct RawNotification {
pub method: String,
pub params: Value,
}
#[derive(Debug, Serialize, Deserialize)]
pub struct RawResponse {
pub id: Option<u64>,
pub result: Value,
pub error: Value,
}
struct MsgReceiver {
chan: Receiver<RawMsg>,
thread: Option<thread::JoinHandle<Result<()>>>,
}
impl MsgReceiver {
fn recv(&mut self) -> Result<RawMsg> {
match self.chan.recv() {
Some(msg) => Ok(msg),
None => {
self.cleanup()?;
unreachable!()
}
}
}
fn cleanup(&mut self) -> Result<()> {
self.thread
.take()
.ok_or_else(|| format_err!("MsgReceiver thread panicked"))?
.join()
.map_err(|_| format_err!("MsgReceiver thread panicked"))??;
bail!("client disconnected")
}
fn stop(self) -> Result<()> {
// Can't really self.thread.join() here, b/c it might be
// blocking on read
Ok(())
}
}
struct MsgSender {
chan: Sender<RawMsg>,
thread: thread::JoinHandle<Result<()>>,
}
impl MsgSender {
fn send(&mut self, msg: RawMsg) {
self.chan.send(msg)
}
fn stop(self) -> Result<()> {
drop(self.chan);
self.thread.join()
.map_err(|_| format_err!("MsgSender thread panicked"))??;
Ok(())
}
}
pub struct Io {
receiver: MsgReceiver,
sender: MsgSender,
}
impl Io {
pub fn from_stdio() -> Io {
let sender = {
let (tx, rx) = bounded(16);
MsgSender {
chan: tx,
thread: thread::spawn(move || {
let stdout = stdout();
let mut stdout = stdout.lock();
for msg in rx {
#[derive(Serialize)]
struct JsonRpc {
jsonrpc: &'static str,
#[serde(flatten)]
msg: RawMsg,
}
let text = to_string(&JsonRpc {
jsonrpc: "2.0",
msg,
})?;
write_msg_text(&mut stdout, &text)?;
}
Ok(())
}),
}
};
let receiver = {
let (tx, rx) = bounded(16);
MsgReceiver {
chan: rx,
thread: Some(thread::spawn(move || {
let stdin = stdin();
let mut stdin = stdin.lock();
while let Some(text) = read_msg_text(&mut stdin)? {
let msg: RawMsg = from_str(&text)?;
tx.send(msg);
}
Ok(())
})),
}
};
Io { receiver, sender }
}
pub fn send(&mut self, msg: RawMsg) {
self.sender.send(msg)
}
pub fn recv(&mut self) -> Result<RawMsg> {
self.receiver.recv()
}
pub fn receiver(&mut self) -> &mut Receiver<RawMsg> {
&mut self.receiver.chan
}
pub fn cleanup_receiver(&mut self) -> Result<()> {
self.receiver.cleanup()
}
pub fn stop(self) -> Result<()> {
self.receiver.stop()?;
self.sender.stop()?;
Ok(())
}
}
fn read_msg_text(inp: &mut impl BufRead) -> Result<Option<String>> {
let mut size = None;
let mut buf = String::new();
loop {
buf.clear();
if inp.read_line(&mut buf)? == 0 {
return Ok(None);
}
if !buf.ends_with("\r\n") {
bail!("malformed header: {:?}", buf);
}
let buf = &buf[..buf.len() - 2];
if buf.is_empty() {
break;
}
let mut parts = buf.splitn(2, ": ");
let header_name = parts.next().unwrap();
let header_value = parts.next().ok_or_else(|| format_err!("malformed header: {:?}", buf))?;
if header_name == "Content-Length" {
size = Some(header_value.parse::<usize>()?);
}
}
let size = size.ok_or_else(|| format_err!("no Content-Length"))?;
let mut buf = buf.into_bytes();
buf.resize(size, 0);
inp.read_exact(&mut buf)?;
let buf = String::from_utf8(buf)?;
debug!("< {}", buf);
Ok(Some(buf))
}
fn write_msg_text(out: &mut impl Write, msg: &str) -> Result<()> {
debug!("> {}", msg);
write!(out, "Content-Length: {}\r\n\r\n", msg.len())?;
out.write_all(msg.as_bytes())?;
out.flush()?;
Ok(())
}
|
