Merge branch 'lsp-async-init'

1 files changed, 115 insertions, 22 deletions

diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
index 67b7b48f..6e28094d 100644
--- a/helix-lsp/src/transport.rs
+++ b/helix-lsp/src/transport.rs
@@ -1,7 +1,7 @@
-use crate::Result;
+use crate::{Error, Result};
 use anyhow::Context;
 use jsonrpc_core as jsonrpc;
-use log::{debug, error, info, warn};
+use log::{error, info};
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use std::collections::HashMap;
@@ -11,7 +11,7 @@ use tokio::{
     process::{ChildStderr, ChildStdin, ChildStdout},
     sync::{
         mpsc::{unbounded_channel, Sender, UnboundedReceiver, UnboundedSender},
-        Mutex,
+        Mutex, Notify,
     },
 };
 
@@ -51,9 +51,11 @@ impl Transport {
     ) -> (
         UnboundedReceiver<(usize, jsonrpc::Call)>,
         UnboundedSender<Payload>,
+        Arc<Notify>,
     ) {
         let (client_tx, rx) = unbounded_channel();
         let (tx, client_rx) = unbounded_channel();
+        let notify = Arc::new(Notify::new());
 
         let transport = Self {
             id,
@@ -62,11 +64,21 @@ impl Transport {
 
         let transport = Arc::new(transport);
 
-        tokio::spawn(Self::recv(transport.clone(), server_stdout, client_tx));
+        tokio::spawn(Self::recv(
+            transport.clone(),
+            server_stdout,
+            client_tx.clone(),
+        ));
         tokio::spawn(Self::err(transport.clone(), server_stderr));
-        tokio::spawn(Self::send(transport, server_stdin, client_rx));
-
-        (rx, tx)
+        tokio::spawn(Self::send(
+            transport,
+            server_stdin,
+            client_tx,
+            client_rx,
+            notify.clone(),
+        ));
+
+        (rx, tx, notify)
     }
 
     async fn recv_server_message(
@@ -76,14 +88,18 @@ impl Transport {
         let mut content_length = None;
         loop {
             buffer.truncate(0);
-            reader.read_line(buffer).await?;
-            let header = buffer.trim();
+            if reader.read_line(buffer).await? == 0 {
+                return Err(Error::StreamClosed);
+            };
+
+            // debug!("<- header {:?}", buffer);
 
-            if header.is_empty() {
+            if buffer == "\r\n" {
+                // look for an empty CRLF line
                 break;
             }
 
-            debug!("<- header {}", header);
+            let header = buffer.trim();
 
             let parts = header.split_once(": ");
 
@@ -96,7 +112,8 @@ impl Transport {
                     // Workaround: Some non-conformant language servers will output logging and other garbage
                     // into the same stream as JSON-RPC messages. This can also happen from shell scripts that spawn
                     // the server. Skip such lines and log a warning.
-                    warn!("Failed to parse header: {:?}", header);
+
+                    // warn!("Failed to parse header: {:?}", header);
                 }
             }
         }
@@ -121,8 +138,10 @@ impl Transport {
         buffer: &mut String,
     ) -> Result<()> {
         buffer.truncate(0);
-        err.read_line(buffer).await?;
-        error!("err <- {}", buffer);
+        if err.read_line(buffer).await? == 0 {
+            return Err(Error::StreamClosed);
+        };
+        error!("err <- {:?}", buffer);
 
         Ok(())
     }
@@ -255,16 +274,90 @@ impl Transport {
     async fn send(
         transport: Arc<Self>,
         mut server_stdin: BufWriter<ChildStdin>,
+        client_tx: UnboundedSender<(usize, jsonrpc::Call)>,
         mut client_rx: UnboundedReceiver<Payload>,
+        initialize_notify: Arc<Notify>,
     ) {
-        while let Some(msg) = client_rx.recv().await {
-            match transport
-                .send_payload_to_server(&mut server_stdin, msg)
-                .await
-            {
-                Ok(_) => {}
-                Err(err) => {
-                    error!("err: <- {:?}", err);
+        let mut pending_messages: Vec<Payload> = Vec::new();
+        let mut is_pending = true;
+
+        // Determine if a message is allowed to be sent early
+        fn is_initialize(payload: &Payload) -> bool {
+            use lsp_types::{
+                notification::{Initialized, Notification},
+                request::{Initialize, Request},
+            };
+            match payload {
+                Payload::Request {
+                    value: jsonrpc::MethodCall { method, .. },
+                    ..
+                } if method == Initialize::METHOD => true,
+                Payload::Notification(jsonrpc::Notification { method, .. })
+                    if method == Initialized::METHOD =>
+                {
+                    true
+                }
+                _ => false,
+            }
+        }
+
+        // TODO: events that use capabilities need to do the right thing
+
+        loop {
+            tokio::select! {
+                biased;
+                _ = initialize_notify.notified() => { // TODO: notified is technically not cancellation safe
+                    // server successfully initialized
+                    is_pending = false;
+
+                    use lsp_types::notification::Notification;
+                    // Hack: inject an initialized notification so we trigger code that needs to happen after init
+                    let notification = ServerMessage::Call(jsonrpc::Call::Notification(jsonrpc::Notification {
+                        jsonrpc: None,
+
+                        method: lsp_types::notification::Initialized::METHOD.to_string(),
+                        params: jsonrpc::Params::None,
+                    }));
+                    match transport.process_server_message(&client_tx, notification).await {
+                        Ok(_) => {}
+                        Err(err) => {
+                            error!("err: <- {:?}", err);
+                        }
+                    }
+
+                    // drain the pending queue and send payloads to server
+                    for msg in pending_messages.drain(..) {
+                        log::info!("Draining pending message {:?}", msg);
+                        match transport.send_payload_to_server(&mut server_stdin, msg).await {
+                            Ok(_) => {}
+                            Err(err) => {
+                                error!("err: <- {:?}", err);
+                            }
+                        }
+                    }
+                }
+                msg = client_rx.recv() => {
+                    if let Some(msg) = msg {
+                        if is_pending && !is_initialize(&msg) {
+                            // ignore notifications
+                            if let Payload::Notification(_) = msg {
+                                continue;
+                            }
+
+                            log::info!("Language server not initialized, delaying request");
+                            pending_messages.push(msg);
+                        } else {
+                            match transport.send_payload_to_server(&mut server_stdin, msg).await {
+                                Ok(_) => {}
+                                Err(err) => {
+                                    error!("err: <- {:?}", err);
+                                }
+                            }
+                        }
+                    } else {
+                        // channel closed
+                        break;
+                    }
                 }
             }
         }