6 files changed, 107 insertions, 190 deletions

diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 458089e53..2b46e8905 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -32,7 +32,7 @@ threadpool = "1.7.1"
 
 stdx = { path = "../stdx" }
 
-lsp-server = "0.3.2"
+lsp-server = "0.3.3"
 ra_flycheck = { path = "../ra_flycheck" }
 ra_ide = { path = "../ra_ide" }
 ra_prof = { path = "../ra_prof" }
diff --git a/crates/rust-analyzer/src/global_state.rs b/crates/rust-analyzer/src/global_state.rs
index d1897bf50..d04ef4c61 100644
--- a/crates/rust-analyzer/src/global_state.rs
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -20,7 +20,7 @@ use stdx::format_to;
 use crate::{
     config::{Config, FilesWatcher},
     diagnostics::{CheckFixes, DiagnosticCollection},
-    main_loop::req_queue::{CompletedInRequest, LatestRequests},
+    main_loop::request_metrics::{LatestRequests, RequestMetrics},
     to_proto::url_from_abs_path,
     vfs_glob::{Glob, RustPackageFilterBuilder},
     LspError, Result,
@@ -55,10 +55,10 @@ pub struct GlobalState {
     pub analysis_host: AnalysisHost,
     pub vfs: Arc<RwLock<Vfs>>,
     pub task_receiver: Receiver<VfsTask>,
-    pub latest_requests: Arc<RwLock<LatestRequests>>,
     pub flycheck: Option<Flycheck>,
     pub diagnostics: DiagnosticCollection,
     pub proc_macro_client: ProcMacroClient,
+    pub(crate) latest_requests: Arc<RwLock<LatestRequests>>,
 }
 
 /// An immutable snapshot of the world's state at a point in time.
@@ -66,8 +66,8 @@ pub struct GlobalStateSnapshot {
     pub config: Config,
     pub workspaces: Arc<Vec<ProjectWorkspace>>,
     pub analysis: Analysis,
-    pub latest_requests: Arc<RwLock<LatestRequests>>,
     pub check_fixes: CheckFixes,
+    pub(crate) latest_requests: Arc<RwLock<LatestRequests>>,
     vfs: Arc<RwLock<Vfs>>,
 }
 
@@ -236,7 +236,7 @@ impl GlobalState {
         self.analysis_host.collect_garbage()
     }
 
-    pub(crate) fn complete_request(&mut self, request: CompletedInRequest) {
+    pub(crate) fn complete_request(&mut self, request: RequestMetrics) {
         self.latest_requests.write().record(request)
     }
 }
diff --git a/crates/rust-analyzer/src/lib.rs b/crates/rust-analyzer/src/lib.rs
index 609cb69d3..64e70955f 100644
--- a/crates/rust-analyzer/src/lib.rs
+++ b/crates/rust-analyzer/src/lib.rs
@@ -32,7 +32,7 @@ mod semantic_tokens;
 
 use serde::de::DeserializeOwned;
 
-pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
+pub type Result<T, E = Box<dyn std::error::Error + Send + Sync>> = std::result::Result<T, E>;
 pub use crate::{
     caps::server_capabilities,
     main_loop::LspError,
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index fd40b2443..674b1323b 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -3,7 +3,7 @@
 
 mod handlers;
 mod subscriptions;
-pub(crate) mod req_queue;
+pub(crate) mod request_metrics;
 
 use std::{
     borrow::Cow,
@@ -17,11 +17,13 @@ use std::{
 };
 
 use crossbeam_channel::{never, select, unbounded, RecvError, Sender};
-use lsp_server::{Connection, ErrorCode, Message, Notification, Request, RequestId, Response};
+use lsp_server::{
+    Connection, ErrorCode, Message, Notification, ReqQueue, Request, RequestId, Response,
+};
 use lsp_types::{
-    DidChangeTextDocumentParams, NumberOrString, TextDocumentContentChangeEvent, WorkDoneProgress,
-    WorkDoneProgressBegin, WorkDoneProgressCreateParams, WorkDoneProgressEnd,
-    WorkDoneProgressReport,
+    request::Request as _, DidChangeTextDocumentParams, NumberOrString,
+    TextDocumentContentChangeEvent, WorkDoneProgress, WorkDoneProgressBegin,
+    WorkDoneProgressCreateParams, WorkDoneProgressEnd, WorkDoneProgressReport,
 };
 use ra_flycheck::{CheckTask, Status};
 use ra_ide::{Canceled, FileId, LineIndex};
@@ -37,10 +39,9 @@ use crate::{
     from_proto,
     global_state::{file_id_to_url, GlobalState, GlobalStateSnapshot},
     lsp_ext,
-    main_loop::subscriptions::Subscriptions,
+    main_loop::{request_metrics::RequestMetrics, subscriptions::Subscriptions},
     Result,
 };
-use req_queue::ReqQueue;
 
 #[derive(Debug)]
 pub struct LspError {
@@ -150,10 +151,11 @@ pub fn main_loop(config: Config, connection: Connection) -> Result<()> {
                 register_options: Some(serde_json::to_value(registration_options).unwrap()),
             };
             let params = lsp_types::RegistrationParams { registrations: vec![registration] };
-            let request = loop_state
-                .req_queue
-                .outgoing
-                .register::<lsp_types::request::RegisterCapability>(params, |_, _| ());
+            let request = loop_state.req_queue.outgoing.register(
+                lsp_types::request::RegisterCapability::METHOD.to_string(),
+                params,
+                DO_NOTHING,
+            );
             connection.sender.send(request.into()).unwrap();
         }
 
@@ -261,9 +263,13 @@ impl fmt::Debug for Event {
     }
 }
 
+type ReqHandler = fn(&mut GlobalState, Response);
+const DO_NOTHING: ReqHandler = |_, _| ();
+type Incoming = lsp_server::Incoming<(&'static str, Instant)>;
+
 #[derive(Default)]
 struct LoopState {
-    req_queue: ReqQueue<fn(&mut GlobalState, lsp_server::Response)>,
+    req_queue: ReqQueue<(&'static str, Instant), ReqHandler>,
     subscriptions: Subscriptions,
     workspace_loaded: bool,
     roots_progress_reported: Option<usize>,
@@ -367,14 +373,19 @@ fn loop_turn(
 fn on_task(
     task: Task,
     msg_sender: &Sender<Message>,
-    incoming_requests: &mut req_queue::Incoming,
+    incoming_requests: &mut Incoming,
     state: &mut GlobalState,
 ) {
     match task {
         Task::Respond(response) => {
-            if let Some(completed) = incoming_requests.complete(response.id.clone()) {
-                log::info!("handled req#{} in {:?}", completed.id, completed.duration);
-                state.complete_request(completed);
+            if let Some((method, start)) = incoming_requests.complete(response.id.clone()) {
+                let duration = start.elapsed();
+                log::info!("handled req#{} in {:?}", response.id, duration);
+                state.complete_request(RequestMetrics {
+                    id: response.id.clone(),
+                    method: method.to_string(),
+                    duration,
+                });
                 msg_sender.send(response.into()).unwrap();
             }
         }
@@ -387,7 +398,7 @@ fn on_task(
 
 fn on_request(
     global_state: &mut GlobalState,
-    incoming_requests: &mut req_queue::Incoming,
+    incoming_requests: &mut Incoming,
     pool: &ThreadPool,
     task_sender: &Sender<Task>,
     msg_sender: &Sender<Message>,
@@ -527,37 +538,35 @@ fn on_notification(
         Ok(_) => {
             // As stated in https://github.com/microsoft/language-server-protocol/issues/676,
             // this notification's parameters should be ignored and the actual config queried separately.
-            let request = loop_state
-                .req_queue
-                .outgoing
-                .register::<lsp_types::request::WorkspaceConfiguration>(
-                    lsp_types::ConfigurationParams {
-                        items: vec![lsp_types::ConfigurationItem {
-                            scope_uri: None,
-                            section: Some("rust-analyzer".to_string()),
-                        }],
-                    },
-                    |global_state, resp| {
-                        log::debug!("config update response: '{:?}", resp);
-                        let Response { error, result, .. } = resp;
-
-                        match (error, result) {
-                            (Some(err), _) => {
-                                log::error!("failed to fetch the server settings: {:?}", err)
-                            }
-                            (None, Some(configs)) => {
-                                if let Some(new_config) = configs.get(0) {
-                                    let mut config = global_state.config.clone();
-                                    config.update(&new_config);
-                                    global_state.update_configuration(config);
-                                }
+            let request = loop_state.req_queue.outgoing.register(
+                lsp_types::request::WorkspaceConfiguration::METHOD.to_string(),
+                lsp_types::ConfigurationParams {
+                    items: vec![lsp_types::ConfigurationItem {
+                        scope_uri: None,
+                        section: Some("rust-analyzer".to_string()),
+                    }],
+                },
+                |global_state, resp| {
+                    log::debug!("config update response: '{:?}", resp);
+                    let Response { error, result, .. } = resp;
+
+                    match (error, result) {
+                        (Some(err), _) => {
+                            log::error!("failed to fetch the server settings: {:?}", err)
+                        }
+                        (None, Some(configs)) => {
+                            if let Some(new_config) = configs.get(0) {
+                                let mut config = global_state.config.clone();
+                                config.update(&new_config);
+                                global_state.update_configuration(config);
                             }
-                            (None, None) => log::error!(
-                                "received empty server settings response from the client"
-                            ),
                         }
-                    },
-                );
+                        (None, None) => {
+                            log::error!("received empty server settings response from the client")
+                        }
+                    }
+                },
+            );
             msg_sender.send(request.into())?;
 
             return Ok(());
@@ -727,15 +736,13 @@ fn send_startup_progress(sender: &Sender<Message>, loop_state: &mut LoopState) {
 
     match (prev, loop_state.workspace_loaded) {
         (None, false) => {
-            let request = loop_state
-                .req_queue
-                .outgoing
-                .register::<lsp_types::request::WorkDoneProgressCreate>(
-                    WorkDoneProgressCreateParams {
-                        token: lsp_types::ProgressToken::String("rustAnalyzer/startup".into()),
-                    },
-                    |_, _| (),
-                );
+            let request = loop_state.req_queue.outgoing.register(
+                lsp_types::request::WorkDoneProgressCreate::METHOD.to_string(),
+                WorkDoneProgressCreateParams {
+                    token: lsp_types::ProgressToken::String("rustAnalyzer/startup".into()),
+                },
+                DO_NOTHING,
+            );
             sender.send(request.into()).unwrap();
             send_startup_progress_notif(
                 sender,
@@ -778,7 +785,7 @@ struct PoolDispatcher<'a> {
     req: Option<Request>,
     pool: &'a ThreadPool,
     global_state: &'a mut GlobalState,
-    incoming_requests: &'a mut req_queue::Incoming,
+    incoming_requests: &'a mut Incoming,
     msg_sender: &'a Sender<Message>,
     task_sender: &'a Sender<Task>,
     request_received: Instant,
@@ -854,11 +861,7 @@ impl<'a> PoolDispatcher<'a> {
                 return None;
             }
         };
-        self.incoming_requests.register(req_queue::PendingInRequest {
-            id: id.clone(),
-            method: R::METHOD.to_string(),
-            received: self.request_received,
-        });
+        self.incoming_requests.register(id.clone(), (R::METHOD, self.request_received));
         Some((id, params))
     }
 
diff --git a/crates/rust-analyzer/src/main_loop/req_queue.rs b/crates/rust-analyzer/src/main_loop/req_queue.rs
deleted file mode 100644
index 5cf6d916b..000000000
--- a/crates/rust-analyzer/src/main_loop/req_queue.rs
+++ /dev/null
@@ -1,123 +0,0 @@
-//! Manages the set of in-flight requests in both directions.
-use std::time::{Duration, Instant};
-
-use lsp_server::RequestId;
-use rustc_hash::FxHashMap;
-use serde::Serialize;
-
-#[derive(Debug)]
-pub(crate) struct ReqQueue<H> {
-    pub(crate) incoming: Incoming,
-    pub(crate) outgoing: Outgoing<H>,
-}
-
-impl<H> Default for ReqQueue<H> {
-    fn default() -> Self {
-        ReqQueue { incoming: Incoming::default(), outgoing: Outgoing::default() }
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct Outgoing<H> {
-    next: u64,
-    pending: FxHashMap<RequestId, H>,
-}
-
-impl<H> Default for Outgoing<H> {
-    fn default() -> Self {
-        Outgoing { next: 0, pending: FxHashMap::default() }
-    }
-}
-
-impl<H> Outgoing<H> {
-    pub(crate) fn register<R>(&mut self, params: R::Params, handler: H) -> lsp_server::Request
-    where
-        R: lsp_types::request::Request,
-        R::Params: Serialize,
-    {
-        let id = RequestId::from(self.next);
-        self.next += 1;
-        self.pending.insert(id.clone(), handler);
-        lsp_server::Request::new(id, R::METHOD.to_string(), params)
-    }
-    pub(crate) fn complete(&mut self, id: RequestId) -> H {
-        self.pending.remove(&id).unwrap()
-    }
-}
-
-#[derive(Debug)]
-pub(crate) struct CompletedInRequest {
-    pub(crate) id: RequestId,
-    pub(crate) method: String,
-    pub(crate) duration: Duration,
-}
-
-#[derive(Debug)]
-pub(crate) struct PendingInRequest {
-    pub(crate) id: RequestId,
-    pub(crate) method: String,
-    pub(crate) received: Instant,
-}
-
-impl From<PendingInRequest> for CompletedInRequest {
-    fn from(pending: PendingInRequest) -> CompletedInRequest {
-        CompletedInRequest {
-            id: pending.id,
-            method: pending.method,
-            duration: pending.received.elapsed(),
-        }
-    }
-}
-
-#[derive(Debug, Default)]
-pub(crate) struct Incoming {
-    pending: FxHashMap<RequestId, PendingInRequest>,
-}
-
-impl Incoming {
-    pub(crate) fn register(&mut self, request: PendingInRequest) {
-        let id = request.id.clone();
-        let prev = self.pending.insert(id.clone(), request);
-        assert!(prev.is_none(), "duplicate request with id {}", id);
-    }
-    pub(crate) fn cancel(&mut self, id: RequestId) -> Option<lsp_server::Response> {
-        if self.pending.remove(&id).is_some() {
-            Some(lsp_server::Response::new_err(
-                id,
-                lsp_server::ErrorCode::RequestCanceled as i32,
-                "canceled by client".to_string(),
-            ))
-        } else {
-            None
-        }
-    }
-    pub(crate) fn complete(&mut self, id: RequestId) -> Option<CompletedInRequest> {
-        self.pending.remove(&id).map(CompletedInRequest::from)
-    }
-}
-
-const N_COMPLETED_REQUESTS: usize = 10;
-
-#[derive(Debug, Default)]
-pub struct LatestRequests {
-    // hand-rolling VecDeque here to print things in a nicer way
-    buf: [Option<CompletedInRequest>; N_COMPLETED_REQUESTS],
-    idx: usize,
-}
-
-impl LatestRequests {
-    pub(crate) fn record(&mut self, request: CompletedInRequest) {
-        // special case: don't track status request itself
-        if request.method == "rust-analyzer/analyzerStatus" {
-            return;
-        }
-        let idx = self.idx;
-        self.buf[idx] = Some(request);
-        self.idx = (idx + 1) % N_COMPLETED_REQUESTS;
-    }
-
-    pub(crate) fn iter(&self) -> impl Iterator<Item = (bool, &CompletedInRequest)> {
-        let idx = self.idx;
-        self.buf.iter().enumerate().filter_map(move |(i, req)| Some((i == idx, req.as_ref()?)))
-    }
-}
diff --git a/crates/rust-analyzer/src/main_loop/request_metrics.rs b/crates/rust-analyzer/src/main_loop/request_metrics.rs
new file mode 100644
index 000000000..b1019e2d6
--- /dev/null
+++ b/crates/rust-analyzer/src/main_loop/request_metrics.rs
@@ -0,0 +1,37 @@
+//! Records stats about requests
+use std::time::Duration;
+
+use lsp_server::RequestId;
+
+#[derive(Debug)]
+pub(crate) struct RequestMetrics {
+    pub(crate) id: RequestId,
+    pub(crate) method: String,
+    pub(crate) duration: Duration,
+}
+
+const N_COMPLETED_REQUESTS: usize = 10;
+
+#[derive(Debug, Default)]
+pub(crate) struct LatestRequests {
+    // hand-rolling VecDeque here to print things in a nicer way
+    buf: [Option<RequestMetrics>; N_COMPLETED_REQUESTS],
+    idx: usize,
+}
+
+impl LatestRequests {
+    pub(crate) fn record(&mut self, request: RequestMetrics) {
+        // special case: don't track status request itself
+        if request.method == "rust-analyzer/analyzerStatus" {
+            return;
+        }
+        let idx = self.idx;
+        self.buf[idx] = Some(request);
+        self.idx = (idx + 1) % N_COMPLETED_REQUESTS;
+    }
+
+    pub(crate) fn iter(&self) -> impl Iterator<Item = (bool, &RequestMetrics)> {
+        let idx = self.idx;
+        self.buf.iter().enumerate().filter_map(move |(i, req)| Some((i == idx, req.as_ref()?)))
+    }
+}