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helix/helix-lsp/src/lib.rs

378 lines
11 KiB
Rust

use std::collections::HashMap;
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use jsonrpc_core as jsonrpc;
use lsp_types as lsp;
use serde::{Deserialize, Serialize};
use serde_json::Value;
use smol::channel::{Receiver, Sender};
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use smol::io::{BufReader, BufWriter};
use smol::prelude::*;
use smol::process::{Child, ChildStderr, ChildStdin, ChildStdout, Command, Stdio};
use smol::Executor;
use futures_util::{select, FutureExt};
/// A type representing all possible values sent from the server to the client.
#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
#[serde(deny_unknown_fields)]
#[serde(untagged)]
enum Message {
/// A regular JSON-RPC request output (single response).
Output(jsonrpc::Output),
/// A notification.
Notification(jsonrpc::Notification),
/// A JSON-RPC request
Call(jsonrpc::Call),
}
pub struct Client {
process: Child,
stderr: BufReader<ChildStderr>,
outgoing: Sender<Payload>,
pub request_counter: u64,
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capabilities: Option<lsp::ServerCapabilities>,
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}
impl Client {
pub fn start(ex: &Executor, cmd: &str, args: &[String]) -> Self {
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let mut process = Command::new(cmd)
.args(args)
.stdin(Stdio::piped())
.stdout(Stdio::piped())
.stderr(Stdio::piped())
.spawn()
.expect("Failed to start language server");
// smol makes sure the process is reaped on drop, but using kill_on_drop(true) maybe?
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// TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
let writer = BufWriter::new(process.stdin.take().expect("Failed to open stdin"));
let reader = BufReader::new(process.stdout.take().expect("Failed to open stdout"));
let stderr = BufReader::new(process.stderr.take().expect("Failed to open stderr"));
let (incoming, outgoing) = Transport::start(ex, reader, writer);
Client {
process,
stderr,
outgoing,
request_counter: 0,
capabilities: None,
}
}
fn next_request_id(&mut self) -> jsonrpc::Id {
let id = jsonrpc::Id::Num(self.request_counter);
self.request_counter += 1;
id
}
fn to_params(value: Value) -> anyhow::Result<jsonrpc::Params> {
use jsonrpc::Params;
let params = match value {
Value::Null => Params::None,
Value::Bool(_) | Value::Number(_) | Value::String(_) => Params::Array(vec![value]),
Value::Array(vec) => Params::Array(vec),
Value::Object(map) => Params::Map(map),
};
Ok(params)
}
pub async fn request<R: lsp::request::Request>(
&mut self,
params: R::Params,
) -> anyhow::Result<R::Result>
where
R::Params: serde::Serialize,
R::Result: core::fmt::Debug, // TODO: temporary
{
let params = serde_json::to_value(params)?;
let request = jsonrpc::MethodCall {
jsonrpc: Some(jsonrpc::Version::V2),
id: self.next_request_id(),
method: R::METHOD.to_string(),
params: Self::to_params(params)?,
};
let (tx, rx) = smol::channel::bounded::<anyhow::Result<Value>>(1);
self.outgoing
.send(Payload::Request {
chan: tx,
value: request,
})
.await?;
let response = rx.recv().await??;
let response = serde_json::from_value(response)?;
// TODO: we should pass request to a sender thread via a channel
// so it can't be interleaved
// TODO: responses can be out of order, we need to register a single shot response channel
Ok(response)
}
pub async fn notify<R: lsp::notification::Notification>(
&mut self,
params: R::Params,
) -> anyhow::Result<()>
where
R::Params: serde::Serialize,
{
let params = serde_json::to_value(params)?;
let notification = jsonrpc::Notification {
jsonrpc: Some(jsonrpc::Version::V2),
method: R::METHOD.to_string(),
params: Self::to_params(params)?,
};
self.outgoing
.send(Payload::Notification(notification))
.await?;
Ok(())
}
// -------------------------------------------------------------------------------------------
// General messages
// -------------------------------------------------------------------------------------------
pub async fn initialize(&mut self) -> anyhow::Result<()> {
// TODO: delay any requests that are triggered prior to initialize
#[allow(deprecated)]
let params = lsp::InitializeParams {
process_id: Some(u64::from(std::process::id())),
root_path: None,
// root_uri: Some(lsp_types::Url::parse("file://localhost/")?),
root_uri: None, // set to project root in the future
initialization_options: None,
capabilities: lsp::ClientCapabilities::default(),
trace: None,
workspace_folders: None,
client_info: None,
};
let response = self.request::<lsp::request::Initialize>(params).await?;
self.capabilities = Some(response.capabilities);
// next up, notify<initialized>
self.notify::<lsp::notification::Initialized>(lsp::InitializedParams {})
.await?;
Ok(())
}
pub async fn shutdown(&mut self) -> anyhow::Result<()> {
self.request::<lsp::request::Shutdown>(()).await
}
pub async fn exit(&mut self) -> anyhow::Result<()> {
self.notify::<lsp::notification::Exit>(()).await
}
// -------------------------------------------------------------------------------------------
// Text document
// -------------------------------------------------------------------------------------------
pub async fn text_document_did_open(&mut self) -> anyhow::Result<()> {
self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
text_document: lsp::TextDocumentItem {
uri: lsp::Url::parse(".")?,
language_id: "rust".to_string(),
version: 0,
text: "".to_string(),
},
})
.await
}
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pub async fn text_document_did_change(&mut self) -> anyhow::Result<()> {
unimplemented!()
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}
// will_save / will_save_wait_until
pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {
unimplemented!()
}
pub async fn text_document_did_close(&mut self) -> anyhow::Result<()> {
unimplemented!()
}
}
enum Payload {
Request {
chan: Sender<anyhow::Result<Value>>,
value: jsonrpc::MethodCall,
},
Notification(jsonrpc::Notification),
}
struct Transport {
incoming: Sender<Message>,
outgoing: Receiver<Payload>,
pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,
headers: HashMap<String, String>,
writer: BufWriter<ChildStdin>,
reader: BufReader<ChildStdout>,
}
impl Transport {
pub fn start(
ex: &Executor,
reader: BufReader<ChildStdout>,
writer: BufWriter<ChildStdin>,
) -> (Receiver<Message>, Sender<Payload>) {
let (incoming, rx) = smol::channel::unbounded();
let (tx, outgoing) = smol::channel::unbounded();
let transport = Self {
reader,
writer,
incoming,
outgoing,
pending_requests: Default::default(),
headers: Default::default(),
};
ex.spawn(transport.duplex()).detach();
(rx, tx)
}
async fn recv(
reader: &mut (impl AsyncBufRead + Unpin),
headers: &mut HashMap<String, String>,
) -> Result<Message, std::io::Error> {
// read headers
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loop {
let mut header = String::new();
// detect pipe closed if 0
reader.read_line(&mut header).await?;
let header = header.trim();
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if header.is_empty() {
break;
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}
let parts: Vec<&str> = header.split(": ").collect();
if parts.len() != 2 {
// return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
panic!()
}
headers.insert(parts[0].to_string(), parts[1].to_string());
}
// find content-length
let content_length = headers.get("Content-Length").unwrap().parse().unwrap();
let mut content = vec![0; content_length];
reader.read_exact(&mut content).await?;
let msg = String::from_utf8(content).unwrap();
// read data
// try parsing as output (server response) or call (server request)
let output: serde_json::Result<Message> = serde_json::from_str(&msg);
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Ok(output?)
}
pub async fn send_payload(&mut self, payload: Payload) -> anyhow::Result<()> {
match payload {
Payload::Request { chan, value } => {
self.pending_requests.insert(value.id.clone(), chan);
let json = serde_json::to_string(&value)?;
self.send(json).await
}
Payload::Notification(value) => {
let json = serde_json::to_string(&value)?;
self.send(json).await
}
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}
}
pub async fn send(&mut self, request: String) -> anyhow::Result<()> {
println!("-> {}", request);
// send the headers
self.writer
.write_all(format!("Content-Length: {}\r\n\r\n", request.len()).as_bytes())
.await?;
// send the body
self.writer.write_all(request.as_bytes()).await?;
self.writer.flush().await?;
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Ok(())
}
pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
match output {
jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
println!("<- {}", result);
let tx = self
.pending_requests
.remove(&id)
.expect("pending_request with id not found!");
tx.send(Ok(result)).await?;
}
jsonrpc::Output::Failure(_) => panic!("recv fail"),
msg => unimplemented!("{:?}", msg),
}
Ok(())
}
pub async fn duplex(mut self) {
loop {
select! {
// client -> server
msg = self.outgoing.next().fuse() => {
if msg.is_none() {
break;
}
let msg = msg.unwrap();
self.send_payload(msg).await.unwrap();
}
// server <- client
msg = Self::recv(&mut self.reader, &mut self.headers).fuse() => {
if msg.is_err() {
break;
}
let msg = msg.unwrap();
match msg {
Message::Output(output) => self.recv_response(output).await.unwrap(),
Message::Notification(_) => {
// dispatch
}
Message::Call(_) => {
// dispatch
}
};
}
}
}
}
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}