Unix sockets (implements #42)

Cargo.toml

@@ -11,6 +11,7 @@ anyhow = "1.0.53"
 clap = { version = "4.3.0", features = ["derive", "env"] }
 directories = "4.0.1"
 percent-encoding = "2.3.1"
+pin-project-lite = "0.2.14"
 serde = { version = "1.0.186" }
 serde_derive = { version = "1.0.186" }
 serde_json = "1.0.78"

src/client.rs

@@ -6,8 +6,6 @@ use anyhow::{bail, ensure, Context, Result};
 use percent_encoding::percent_decode_str;
 use serde_json::Value;
 use tokio::io::BufReader;
-use tokio::net::tcp::{OwnedReadHalf, OwnedWriteHalf};
-use tokio::net::TcpStream;
 use tokio::sync::mpsc::error::SendError;
 use tokio::sync::{mpsc, Mutex};
 use tokio::task;
@@ -21,11 +19,12 @@ use crate::lsp::jsonrpc::{
 };
 use crate::lsp::transport::{LspReader, LspWriter};
 use crate::lsp::InitializeParams;
+use crate::socketwrapper::{OwnedReadHalf, OwnedWriteHalf, Stream};
 
 /// Read first client message and dispatch lsp mux commands
 pub async fn process(
-    socket: TcpStream,
-    port: u16,
+    socket: Stream,
+    client_id: usize,
     instance_map: Arc<Mutex<InstanceMap>>,
 ) -> Result<()> {
     let (socket_read, socket_write) = socket.into_split();
@@ -70,7 +69,7 @@ pub async fn process(
             cwd,
         } => {
             connect(
-                port,
+                client_id,
                 instance_map,
                 (server, args, env, cwd),
                 req,
@@ -87,18 +86,18 @@ pub async fn process(
 
 #[derive(Clone)]
 pub struct Client {
-    port: u16,
+    id: usize,
     sender: mpsc::Sender<Message>,
 }
 
 impl Client {
-    fn new(port: u16) -> (Client, mpsc::Receiver<Message>) {
+    fn new(id: usize) -> (Client, mpsc::Receiver<Message>) {
         let (sender, receiver) = mpsc::channel(16);
-        (Client { port, sender }, receiver)
+        (Client { id, sender }, receiver)
     }
 
-    pub fn port(&self) -> u16 {
-        self.port
+    pub fn id(&self) -> usize {
+        self.id
     }
 
     /// Send a message to the client channel
@@ -168,7 +167,7 @@ async fn reload(
 
 /// Find or spawn a language server instance and connect the client to it
 async fn connect(
-    port: u16,
+    client_id: usize,
     instance_map: Arc<Mutex<InstanceMap>>,
     (server, args, env, cwd): (
         String,
@@ -224,7 +223,7 @@ async fn connect(
     }
     info!("initialized client");
 
-    let (client, client_rx) = Client::new(port);
+    let (client, client_rx) = Client::new(client_id);
     task::spawn(input_task(client_rx, writer).in_current_span());
     instance.add_client(client.clone()).await;
 
@@ -346,7 +345,7 @@ async fn output_task(
             }
 
             Message::Request(mut req) => {
-                req.id = req.id.tag(Tag::Port(client.port));
+                req.id = req.id.tag(Tag::ClientId(client.id));
                 if instance.send_message(req.into()).await.is_err() {
                     break;
                 }
@@ -372,13 +371,13 @@ async fn output_task(
             }
 
             Message::Notification(notif) if notif.method == "textDocument/didOpen" => {
-                if let Err(err) = instance.open_file(client.port, notif.params).await {
+                if let Err(err) = instance.open_file(client.id, notif.params).await {
                     warn!(?err, "error opening file");
                 }
             }
 
             Message::Notification(notif) if notif.method == "textDocument/didClose" => {
-                if let Err(err) = instance.close_file(client.port, notif.params).await {
+                if let Err(err) = instance.close_file(client.id, notif.params).await {
                     warn!(?err, "error closing file");
                 }
             }

src/config.rs

@@ -1,6 +1,8 @@
 use std::collections::BTreeSet;
 use std::fs;
 use std::net::{IpAddr, Ipv4Addr};
+#[cfg(target_family = "unix")]
+use std::path::PathBuf;
 
 use anyhow::{Context, Result};
 use directories::ProjectDirs;
@@ -21,12 +23,12 @@ mod default {
         10
     }
 
-    pub fn listen() -> (IpAddr, u16) {
+    pub fn listen() -> Address {
         // localhost & some random unprivileged port
-        (IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 27_631)
+        Address::Tcp(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 27_631)
     }
 
-    pub fn connect() -> (IpAddr, u16) {
+    pub fn connect() -> Address {
         listen()
     }
 
@@ -82,6 +84,14 @@ mod de {
     }
 }
 
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(untagged)]
+pub enum Address {
+    Tcp(IpAddr, u16),
+    #[cfg(target_family = "unix")]
+    Unix(PathBuf),
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 #[serde(deny_unknown_fields)]
 pub struct Config {
@@ -94,10 +104,10 @@ pub struct Config {
     pub gc_interval: u32,
 
     #[serde(default = "default::listen")]
-    pub listen: (IpAddr, u16),
+    pub listen: Address,
 
     #[serde(default = "default::connect")]
-    pub connect: (IpAddr, u16),
+    pub connect: Address,
 
     #[serde(default = "default::log_filters")]
     pub log_filters: String,

src/ext.rs

@@ -3,19 +3,19 @@ use std::env;
 use anyhow::{bail, Context, Result};
 use serde::de::{DeserializeOwned, IgnoredAny};
 use tokio::io::BufReader;
-use tokio::net::TcpStream;
 
 use crate::config::Config;
 use crate::lsp::ext::{self, LspMuxOptions, StatusResponse};
 use crate::lsp::jsonrpc::{Message, Request, RequestId, Version};
 use crate::lsp::transport::{LspReader, LspWriter};
 use crate::lsp::{InitializationOptions, InitializeParams};
+use crate::socketwrapper::Stream;
 
 pub async fn ext_request<T>(config: &Config, method: ext::Request) -> Result<T>
 where
     T: DeserializeOwned,
 {
-    let (reader, writer) = TcpStream::connect(config.connect)
+    let (reader, writer) = Stream::connect(&config.connect)
         .await
         .context("connect")?
         .into_split();
@@ -102,7 +102,7 @@ pub async fn status(config: &Config, json: bool) -> Result<()> {
         println!("  clients:");
         for client in instance.clients {
             println!("    - Client");
-            println!("      port: {}", client.port);
+            println!("      id: {}", client.id);
             println!("      files:");
             for file in client.files {
                 println!("        - {}", file);

src/instance.rs

@@ -49,7 +49,7 @@ pub struct Instance {
     server: mpsc::Sender<Message>,
 
     /// Data of associated clients
-    clients: Mutex<HashMap<u16, ClientData>>,
+    clients: Mutex<HashMap<usize, ClientData>>,
 
     /// Dynamic capabilities registered by the server
     dynamic_capabilities: Mutex<HashMap<String, lsp::Registration>>,
@@ -83,7 +83,7 @@ struct ClientData {
 impl ClientData {
     fn get_status(&self) -> ext::Client {
         ext::Client {
-            port: self.client.port(),
+            id: self.client.id(),
             files: self.files.iter().cloned().collect(),
         }
     }
@@ -146,8 +146,8 @@ impl Instance {
             client,
             files: HashSet::new(),
         };
-        if clients.insert(client.port(), client).is_some() {
-            unreachable!("BUG: added two clients with the same port");
+        if clients.insert(client.id(), client).is_some() {
+            unreachable!("BUG: added two clients with the same ID");
         }
     }
 
@@ -157,7 +157,7 @@ impl Instance {
 
         let mut clients = self.clients.lock().await;
 
-        let Some(client) = clients.remove(&client.port()) else {
+        let Some(client) = clients.remove(&client.id()) else {
             // TODO This happens for example when the language server died while
             // client was still connected, and the client cleanup is attempted
             // with the instance being gone already. We should try notifying
@@ -205,7 +205,7 @@ impl Instance {
     }
 
     /// Handle `textDocument/didOpen` client notification
-    pub async fn open_file(&self, port: u16, params: Value) -> Result<()> {
+    pub async fn open_file(&self, client_id: usize, params: Value) -> Result<()> {
         let params = serde_json::from_value::<lsp::DidOpenTextDocumentParams>(params)
             .context("parsing params")?;
         let uri = &params.text_document.uri;
@@ -222,7 +222,7 @@ impl Instance {
         }
 
         clients
-            .get_mut(&port)
+            .get_mut(&client_id)
             .expect("no matching client")
             .files
             .insert(uri.clone());
@@ -241,14 +241,14 @@ impl Instance {
     }
 
     /// Handle `textDocument/didClose` client notification
-    pub async fn close_file(&self, port: u16, params: Value) -> Result<()> {
+    pub async fn close_file(&self, client_id: usize, params: Value) -> Result<()> {
         let params = serde_json::from_value::<lsp::DidCloseTextDocumentParams>(params)
             .context("parsing params")?;
 
         let mut clients = self.clients.lock().await;
 
         clients
-            .get_mut(&port)
+            .get_mut(&client_id)
             .context("no matching client")?
             .files
             .remove(&params.text_document.uri);
@@ -261,7 +261,7 @@ impl Instance {
     /// definitely closed files
     async fn close_all_files(
         &self,
-        clients: &HashMap<u16, ClientData>,
+        clients: &HashMap<usize, ClientData>,
         files: Vec<String>,
     ) -> Result<()> {
         for uri in files {
@@ -643,12 +643,12 @@ async fn stdout_task(instance: Arc<Instance>, mut reader: LspReader<BufReader<Ch
                 // Forward successful response to the right client based on the
                 // Request ID tag.
                 match res.id.untag() {
-                    (Some(Tag::Port(port)), id) => {
+                    (Some(Tag::ClientId(client_id)), id) => {
                         res.id = id;
-                        if let Some(client) = clients.get(&port) {
+                        if let Some(client) = clients.get(&client_id) {
                             let _ = client.send_message(res.into()).await;
                         } else {
-                            debug!(?port, "no matching client");
+                            debug!(?client_id, "no matching client");
                         }
                     }
                     (Some(Tag::Drop), _) => {
@@ -664,13 +664,13 @@ async fn stdout_task(instance: Arc<Instance>, mut reader: LspReader<BufReader<Ch
                 // Forward the error response to the right client based on the
                 // Request ID tag.
                 match res.id.untag() {
-                    (Some(Tag::Port(port)), id) => {
+                    (Some(Tag::ClientId(client_id)), id) => {
                         warn!(?res, "server responded with error");
                         res.id = id;
-                        if let Some(client) = clients.get(&port) {
+                        if let Some(client) = clients.get(&client_id) {
                             let _ = client.send_message(res.into()).await;
                         } else {
-                            debug!(?port, "no matching client");
+                            debug!(?client_id, "no matching client");
                         }
                     }
                     (Some(Tag::Drop), _) => {

src/lib.rs

@@ -1,6 +1,7 @@
 mod client;
 mod instance;
 mod lsp;
+mod socketwrapper;
 
 pub mod config;
 pub mod ext;

src/lsp/ext.rs

@@ -11,8 +11,8 @@ use super::jsonrpc::RequestId;
 
 /// Additional metadata inserted into LSP RequestId
 pub enum Tag {
-    /// Request is coming from a client connected on this port
-    Port(u16),
+    /// Request is coming from a client connected with this ID
+    ClientId(usize),
     /// Response to this request should be ignored
     Drop,
     /// Response to this request should be forwarded
@@ -23,7 +23,7 @@ impl RequestId {
     /// Serializes the ID to a string and prepends Tag
     pub fn tag(&self, tag: Tag) -> RequestId {
         let tag = match tag {
-            Tag::Port(port) => format!("port:{port}"),
+            Tag::ClientId(client_id) => format!("client_id:{client_id}"),
             Tag::Drop => "drop".into(),
             Tag::Forward => "forward".into(),
         };
@@ -45,21 +45,21 @@ impl RequestId {
             })
         }
 
-        fn parse_port(input: &str) -> Result<(u16, &str)> {
-            let (port, rest) = input.split_once(':').context("missing`:`")?;
-            let port = u16::from_str(port).context("invalid port number")?;
-            Ok((port, rest))
+        fn parse_client_id(input: &str) -> Result<(usize, &str)> {
+            let (client_id, rest) = input.split_once(':').context("missing`:`")?;
+            let client_id = usize::from_str(client_id).context("invalid client ID")?;
+            Ok((client_id, rest))
         }
 
         fn parse_tag(input: &RequestId) -> Result<(Tag, RequestId)> {
             let RequestId::String(input) = input else {
                 bail!("tagged id must be a String found `{input:?}`");
             };
 
-            if let Some(rest) = input.strip_prefix("port:") {
-                let (port, rest) = parse_port(rest)?;
+            if let Some(rest) = input.strip_prefix("client_id:") {
+                let (client_id, rest) = parse_client_id(rest)?;
                 let inner_id = parse_inner_id(rest).context("failed to parse inner ID")?;
-                return Ok((Tag::Port(port), inner_id));
+                return Ok((Tag::ClientId(client_id), inner_id));
             }
 
             if let Some(rest) = input.strip_prefix("drop:") {
@@ -175,7 +175,7 @@ pub struct Instance {
 #[derive(Serialize, Deserialize, Clone, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct Client {
-    pub port: u16,
+    pub id: usize,
     pub files: Vec<String>,
 }