crates/rust-analyzer/src/main_loop.rs

   1 //! The main loop of `rust-analyzer` responsible for dispatching LSP
   2 //! requests/replies and notifications back to the client.
   3 use std::{
   4     fmt,
   5     sync::Arc,
   6     time::{Duration, Instant},
   7 };
   8
   9 use always_assert::always;
  10 use crossbeam_channel::{select, Receiver};
  11 use ide_db::base_db::{SourceDatabaseExt, VfsPath};
  12 use itertools::Itertools;
  13 use lsp_server::{Connection, Notification, Request};
  14 use lsp_types::notification::Notification as _;
  15 use vfs::{ChangeKind, FileId};
  16
  17 use crate::{
  18     config::Config,
  19     dispatch::{NotificationDispatcher, RequestDispatcher},
  20     from_proto,
  21     global_state::{file_id_to_url, url_to_file_id, GlobalState},
  22     handlers, lsp_ext,
  23     lsp_utils::{apply_document_changes, is_cancelled, notification_is, Progress},
  24     mem_docs::DocumentData,
  25     reload::{self, BuildDataProgress, ProjectWorkspaceProgress},
  26     Result,
  27 };
  28
  29 pub fn main_loop(config: Config, connection: Connection) -> Result<()> {
  30     tracing::info!("initial config: {:#?}", config);
  31
  32     // Windows scheduler implements priority boosts: if thread waits for an
  33     // event (like a condvar), and event fires, priority of the thread is
  34     // temporary bumped. This optimization backfires in our case: each time the
  35     // `main_loop` schedules a task to run on a threadpool, the worker threads
  36     // gets a higher priority, and (on a machine with fewer cores) displaces the
  37     // main loop! We work-around this by marking the main loop as a
  38     // higher-priority thread.
  39     //
  40     // https://docs.microsoft.com/en-us/windows/win32/procthread/scheduling-priorities
  41     // https://docs.microsoft.com/en-us/windows/win32/procthread/priority-boosts
  42     // https://github.com/rust-analyzer/rust-analyzer/issues/2835
  43     #[cfg(windows)]
  44     unsafe {
  45         use winapi::um::processthreadsapi::*;
  46         let thread = GetCurrentThread();
  47         let thread_priority_above_normal = 1;
  48         SetThreadPriority(thread, thread_priority_above_normal);
  49     }
  50
  51     GlobalState::new(connection.sender, config).run(connection.receiver)
  52 }
  53
  54 enum Event {
  55     Lsp(lsp_server::Message),
  56     Task(Task),
  57     Vfs(vfs::loader::Message),
  58     Flycheck(flycheck::Message),
  59 }
  60
  61 #[derive(Debug)]
  62 pub(crate) enum Task {
  63     Response(lsp_server::Response),
  64     Diagnostics(Vec<(FileId, Vec<lsp_types::Diagnostic>)>),
  65     PrimeCaches(PrimeCachesProgress),
  66     FetchWorkspace(ProjectWorkspaceProgress),
  67     FetchBuildData(BuildDataProgress),
  68 }
  69
  70 #[derive(Debug)]
  71 pub(crate) enum PrimeCachesProgress {
  72     Begin,
  73     Report(ide::ParallelPrimeCachesProgress),
  74     End { cancelled: bool },
  75 }
  76
  77 impl fmt::Debug for Event {
  78     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  79         let debug_verbose_not = |not: &Notification, f: &mut fmt::Formatter| {
  80             f.debug_struct("Notification").field("method", &not.method).finish()
  81         };
  82
  83         match self {
  84             Event::Lsp(lsp_server::Message::Notification(not)) => {
  85                 if notification_is::<lsp_types::notification::DidOpenTextDocument>(not)
  86                     || notification_is::<lsp_types::notification::DidChangeTextDocument>(not)
  87                 {
  88                     return debug_verbose_not(not, f);
  89                 }
  90             }
  91             Event::Task(Task::Response(resp)) => {
  92                 return f
  93                     .debug_struct("Response")
  94                     .field("id", &resp.id)
  95                     .field("error", &resp.error)
  96                     .finish();
  97             }
  98             _ => (),
  99         }
 100         match self {
 101             Event::Lsp(it) => fmt::Debug::fmt(it, f),
 102             Event::Task(it) => fmt::Debug::fmt(it, f),
 103             Event::Vfs(it) => fmt::Debug::fmt(it, f),
 104             Event::Flycheck(it) => fmt::Debug::fmt(it, f),
 105         }
 106     }
 107 }
 108
 109 impl GlobalState {
 110     fn run(mut self, inbox: Receiver<lsp_server::Message>) -> Result<()> {
 111         if self.config.linked_projects().is_empty()
 112             && self.config.detached_files().is_empty()
 113             && self.config.notifications().cargo_toml_not_found
 114         {
 115             self.show_message(
 116                 lsp_types::MessageType::ERROR,
 117                 "rust-analyzer failed to discover workspace".to_string(),
 118             );
 119         };
 120
 121         if self.config.did_save_text_document_dynamic_registration() {
 122             let save_registration_options = lsp_types::TextDocumentSaveRegistrationOptions {
 123                 include_text: Some(false),
 124                 text_document_registration_options: lsp_types::TextDocumentRegistrationOptions {
 125                     document_selector: Some(vec![
 126                         lsp_types::DocumentFilter {
 127                             language: None,
 128                             scheme: None,
 129                             pattern: Some("**/*.rs".into()),
 130                         },
 131                         lsp_types::DocumentFilter {
 132                             language: None,
 133                             scheme: None,
 134                             pattern: Some("**/Cargo.toml".into()),
 135                         },
 136                         lsp_types::DocumentFilter {
 137                             language: None,
 138                             scheme: None,
 139                             pattern: Some("**/Cargo.lock".into()),
 140                         },
 141                     ]),
 142                 },
 143             };
 144
 145             let registration = lsp_types::Registration {
 146                 id: "textDocument/didSave".to_string(),
 147                 method: "textDocument/didSave".to_string(),
 148                 register_options: Some(serde_json::to_value(save_registration_options).unwrap()),
 149             };
 150             self.send_request::<lsp_types::request::RegisterCapability>(
 151                 lsp_types::RegistrationParams { registrations: vec![registration] },
 152                 |_, _| (),
 153             );
 154         }
 155
 156         self.fetch_workspaces_queue.request_op();
 157         if self.fetch_workspaces_queue.should_start_op() {
 158             self.fetch_workspaces();
 159         }
 160
 161         while let Some(event) = self.next_event(&inbox) {
 162             if let Event::Lsp(lsp_server::Message::Notification(not)) = &event {
 163                 if not.method == lsp_types::notification::Exit::METHOD {
 164                     return Ok(());
 165                 }
 166             }
 167             self.handle_event(event)?
 168         }
 169
 170         return Err("client exited without proper shutdown sequence".into());
 171     }
 172
 173     fn next_event(&self, inbox: &Receiver<lsp_server::Message>) -> Option<Event> {
 174         select! {
 175             recv(inbox) -> msg =>
 176                 msg.ok().map(Event::Lsp),
 177
 178             recv(self.task_pool.receiver) -> task =>
 179                 Some(Event::Task(task.unwrap())),
 180
 181             recv(self.loader.receiver) -> task =>
 182                 Some(Event::Vfs(task.unwrap())),
 183
 184             recv(self.flycheck_receiver) -> task =>
 185                 Some(Event::Flycheck(task.unwrap())),
 186         }
 187     }
 188
 189     fn handle_event(&mut self, event: Event) -> Result<()> {
 190         let loop_start = Instant::now();
 191         // NOTE: don't count blocking select! call as a loop-turn time
 192         let _p = profile::span("GlobalState::handle_event");
 193
 194         tracing::info!("handle_event({:?})", event);
 195         let task_queue_len = self.task_pool.handle.len();
 196         if task_queue_len > 0 {
 197             tracing::info!("task queue len: {}", task_queue_len);
 198         }
 199
 200         let was_quiescent = self.is_quiescent();
 201         match event {
 202             Event::Lsp(msg) => match msg {
 203                 lsp_server::Message::Request(req) => self.on_request(loop_start, req)?,
 204                 lsp_server::Message::Notification(not) => {
 205                     self.on_notification(not)?;
 206                 }
 207                 lsp_server::Message::Response(resp) => self.complete_request(resp),
 208             },
 209             Event::Task(mut task) => {
 210                 let _p = profile::span("GlobalState::handle_event/task");
 211                 let mut prime_caches_progress = Vec::new();
 212                 loop {
 213                     match task {
 214                         Task::Response(response) => self.respond(response),
 215                         Task::Diagnostics(diagnostics_per_file) => {
 216                             for (file_id, diagnostics) in diagnostics_per_file {
 217                                 self.diagnostics.set_native_diagnostics(file_id, diagnostics)
 218                             }
 219                         }
 220                         Task::PrimeCaches(progress) => match progress {
 221                             PrimeCachesProgress::Begin => prime_caches_progress.push(progress),
 222                             PrimeCachesProgress::Report(_) => {
 223                                 match prime_caches_progress.last_mut() {
 224                                     Some(last @ PrimeCachesProgress::Report(_)) => {
 225                                         // Coalesce subsequent update events.
 226                                         *last = progress;
 227                                     }
 228                                     _ => prime_caches_progress.push(progress),
 229                                 }
 230                             }
 231                             PrimeCachesProgress::End { .. } => prime_caches_progress.push(progress),
 232                         },
 233                         Task::FetchWorkspace(progress) => {
 234                             let (state, msg) = match progress {
 235                                 ProjectWorkspaceProgress::Begin => (Progress::Begin, None),
 236                                 ProjectWorkspaceProgress::Report(msg) => {
 237                                     (Progress::Report, Some(msg))
 238                                 }
 239                                 ProjectWorkspaceProgress::End(workspaces) => {
 240                                     self.fetch_workspaces_queue.op_completed(workspaces);
 241
 242                                     let old = Arc::clone(&self.workspaces);
 243                                     self.switch_workspaces();
 244                                     let workspaces_updated = !Arc::ptr_eq(&old, &self.workspaces);
 245
 246                                     if self.config.run_build_scripts() && workspaces_updated {
 247                                         self.fetch_build_data_queue.request_op()
 248                                     }
 249
 250                                     (Progress::End, None)
 251                                 }
 252                             };
 253
 254                             self.report_progress("Fetching", state, msg, None);
 255                         }
 256                         Task::FetchBuildData(progress) => {
 257                             let (state, msg) = match progress {
 258                                 BuildDataProgress::Begin => (Some(Progress::Begin), None),
 259                                 BuildDataProgress::Report(msg) => {
 260                                     (Some(Progress::Report), Some(msg))
 261                                 }
 262                                 BuildDataProgress::End(build_data_result) => {
 263                                     self.fetch_build_data_queue.op_completed(build_data_result);
 264
 265                                     self.switch_workspaces();
 266
 267                                     (Some(Progress::End), None)
 268                                 }
 269                             };
 270
 271                             if let Some(state) = state {
 272                                 self.report_progress("Loading", state, msg, None);
 273                             }
 274                         }
 275                     }
 276
 277                     // Coalesce multiple task events into one loop turn
 278                     task = match self.task_pool.receiver.try_recv() {
 279                         Ok(task) => task,
 280                         Err(_) => break,
 281                     };
 282                 }
 283
 284                 for progress in prime_caches_progress {
 285                     let (state, message, fraction);
 286                     match progress {
 287                         PrimeCachesProgress::Begin => {
 288                             state = Progress::Begin;
 289                             message = None;
 290                             fraction = 0.0;
 291                         }
 292                         PrimeCachesProgress::Report(report) => {
 293                             state = Progress::Report;
 294
 295                             message = match &report.crates_currently_indexing[..] {
 296                                 [crate_name] => Some(format!(
 297                                     "{}/{} ({})",
 298                                     report.crates_done, report.crates_total, crate_name
 299                                 )),
 300                                 [crate_name, rest @ ..] => Some(format!(
 301                                     "{}/{} ({} + {} more)",
 302                                     report.crates_done,
 303                                     report.crates_total,
 304                                     crate_name,
 305                                     rest.len()
 306                                 )),
 307                                 _ => None,
 308                             };
 309
 310                             fraction = Progress::fraction(report.crates_done, report.crates_total);
 311                         }
 312                         PrimeCachesProgress::End { cancelled } => {
 313                             state = Progress::End;
 314                             message = None;
 315                             fraction = 1.0;
 316
 317                             self.prime_caches_queue.op_completed(());
 318                             if cancelled {
 319                                 self.prime_caches_queue.request_op();
 320                             }
 321                         }
 322                     };
 323
 324                     self.report_progress("Indexing", state, message, Some(fraction));
 325                 }
 326             }
 327             Event::Vfs(mut task) => {
 328                 let _p = profile::span("GlobalState::handle_event/vfs");
 329                 loop {
 330                     match task {
 331                         vfs::loader::Message::Loaded { files } => {
 332                             let vfs = &mut self.vfs.write().0;
 333                             for (path, contents) in files {
 334                                 let path = VfsPath::from(path);
 335                                 if !self.mem_docs.contains(&path) {
 336                                     vfs.set_file_contents(path, contents);
 337                                 }
 338                             }
 339                         }
 340                         vfs::loader::Message::Progress { n_total, n_done, config_version } => {
 341                             always!(config_version <= self.vfs_config_version);
 342
 343                             self.vfs_progress_config_version = config_version;
 344                             self.vfs_progress_n_total = n_total;
 345                             self.vfs_progress_n_done = n_done;
 346
 347                             let state = if n_done == 0 {
 348                                 Progress::Begin
 349                             } else if n_done < n_total {
 350                                 Progress::Report
 351                             } else {
 352                                 assert_eq!(n_done, n_total);
 353                                 Progress::End
 354                             };
 355                             self.report_progress(
 356                                 "Roots Scanned",
 357                                 state,
 358                                 Some(format!("{}/{}", n_done, n_total)),
 359                                 Some(Progress::fraction(n_done, n_total)),
 360                             )
 361                         }
 362                     }
 363                     // Coalesce many VFS event into a single loop turn
 364                     task = match self.loader.receiver.try_recv() {
 365                         Ok(task) => task,
 366                         Err(_) => break,
 367                     }
 368                 }
 369             }
 370             Event::Flycheck(mut task) => {
 371                 let _p = profile::span("GlobalState::handle_event/flycheck");
 372                 loop {
 373                     match task {
 374                         flycheck::Message::AddDiagnostic { workspace_root, diagnostic } => {
 375                             let diagnostics =
 376                                 crate::diagnostics::to_proto::map_rust_diagnostic_to_lsp(
 377                                     &self.config.diagnostics_map(),
 378                                     &diagnostic,
 379                                     &workspace_root,
 380                                 );
 381                             for diag in diagnostics {
 382                                 match url_to_file_id(&self.vfs.read().0, &diag.url) {
 383                                     Ok(file_id) => self.diagnostics.add_check_diagnostic(
 384                                         file_id,
 385                                         diag.diagnostic,
 386                                         diag.fix,
 387                                     ),
 388                                     Err(err) => {
 389                                         tracing::error!(
 390                                             "File with cargo diagnostic not found in VFS: {}",
 391                                             err
 392                                         );
 393                                     }
 394                                 };
 395                             }
 396                         }
 397
 398                         flycheck::Message::Progress { id, progress } => {
 399                             let (state, message) = match progress {
 400                                 flycheck::Progress::DidStart => {
 401                                     self.diagnostics.clear_check();
 402                                     (Progress::Begin, None)
 403                                 }
 404                                 flycheck::Progress::DidCheckCrate(target) => {
 405                                     (Progress::Report, Some(target))
 406                                 }
 407                                 flycheck::Progress::DidCancel => (Progress::End, None),
 408                                 flycheck::Progress::DidFinish(result) => {
 409                                     if let Err(err) = result {
 410                                         self.show_message(
 411                                             lsp_types::MessageType::ERROR,
 412                                             format!("cargo check failed: {}", err),
 413                                         );
 414                                     }
 415                                     (Progress::End, None)
 416                                 }
 417                             };
 418
 419                             // When we're running multiple flychecks, we have to include a disambiguator in
 420                             // the title, or the editor complains. Note that this is a user-facing string.
 421                             let title = if self.flycheck.len() == 1 {
 422                                 match self.config.flycheck() {
 423                                     Some(config) => format!("{}", config),
 424                                     None => "cargo check".to_string(),
 425                                 }
 426                             } else {
 427                                 format!("cargo check (#{})", id + 1)
 428                             };
 429                             self.report_progress(&title, state, message, None);
 430                         }
 431                     }
 432                     // Coalesce many flycheck updates into a single loop turn
 433                     task = match self.flycheck_receiver.try_recv() {
 434                         Ok(task) => task,
 435                         Err(_) => break,
 436                     }
 437                 }
 438             }
 439         }
 440
 441         let state_changed = self.process_changes();
 442         let memdocs_added_or_removed = self.mem_docs.take_changes();
 443
 444         if self.is_quiescent() {
 445             if !was_quiescent {
 446                 for flycheck in &self.flycheck {
 447                     flycheck.update();
 448                 }
 449                 if self.config.prefill_caches() {
 450                     self.prime_caches_queue.request_op();
 451                 }
 452             }
 453
 454             if !was_quiescent || state_changed {
 455                 // Refresh semantic tokens if the client supports it.
 456                 if self.config.semantic_tokens_refresh() {
 457                     self.semantic_tokens_cache.lock().clear();
 458                     self.send_request::<lsp_types::request::SemanticTokensRefesh>((), |_, _| ());
 459                 }
 460
 461                 // Refresh code lens if the client supports it.
 462                 if self.config.code_lens_refresh() {
 463                     self.send_request::<lsp_types::request::CodeLensRefresh>((), |_, _| ());
 464                 }
 465             }
 466
 467             if !was_quiescent || state_changed || memdocs_added_or_removed {
 468                 if self.config.publish_diagnostics() {
 469                     self.update_diagnostics()
 470                 }
 471             }
 472         }
 473
 474         if let Some(diagnostic_changes) = self.diagnostics.take_changes() {
 475             for file_id in diagnostic_changes {
 476                 let db = self.analysis_host.raw_database();
 477                 let source_root = db.file_source_root(file_id);
 478                 if db.source_root(source_root).is_library {
 479                     // Only publish diagnostics for files in the workspace, not from crates.io deps
 480                     // or the sysroot.
 481                     // While theoretically these should never have errors, we have quite a few false
 482                     // positives particularly in the stdlib, and those diagnostics would stay around
 483                     // forever if we emitted them here.
 484                     continue;
 485                 }
 486
 487                 let url = file_id_to_url(&self.vfs.read().0, file_id);
 488                 let diagnostics = self.diagnostics.diagnostics_for(file_id).cloned().collect();
 489                 let version = from_proto::vfs_path(&url)
 490                     .map(|path| self.mem_docs.get(&path).map(|it| it.version))
 491                     .unwrap_or_default();
 492
 493                 self.send_notification::<lsp_types::notification::PublishDiagnostics>(
 494                     lsp_types::PublishDiagnosticsParams { uri: url, diagnostics, version },
 495                 );
 496             }
 497         }
 498
 499         if self.config.cargo_autoreload() {
 500             if self.fetch_workspaces_queue.should_start_op() {
 501                 self.fetch_workspaces();
 502             }
 503         }
 504         if self.fetch_build_data_queue.should_start_op() {
 505             self.fetch_build_data();
 506         }
 507         if self.prime_caches_queue.should_start_op() {
 508             let num_worker_threads = self.config.prime_caches_num_threads();
 509
 510             self.task_pool.handle.spawn_with_sender({
 511                 let analysis = self.snapshot().analysis;
 512                 move |sender| {
 513                     sender.send(Task::PrimeCaches(PrimeCachesProgress::Begin)).unwrap();
 514                     let res = analysis.parallel_prime_caches(num_worker_threads, |progress| {
 515                         let report = PrimeCachesProgress::Report(progress);
 516                         sender.send(Task::PrimeCaches(report)).unwrap();
 517                     });
 518                     sender
 519                         .send(Task::PrimeCaches(PrimeCachesProgress::End {
 520                             cancelled: res.is_err(),
 521                         }))
 522                         .unwrap();
 523                 }
 524             });
 525         }
 526
 527         let status = self.current_status();
 528         if self.last_reported_status.as_ref() != Some(&status) {
 529             self.last_reported_status = Some(status.clone());
 530
 531             if let (lsp_ext::Health::Error, Some(message)) = (status.health, &status.message) {
 532                 self.show_message(lsp_types::MessageType::ERROR, message.clone());
 533             }
 534
 535             if self.config.server_status_notification() {
 536                 self.send_notification::<lsp_ext::ServerStatusNotification>(status);
 537             }
 538         }
 539
 540         let loop_duration = loop_start.elapsed();
 541         if loop_duration > Duration::from_millis(100) && was_quiescent {
 542             tracing::warn!("overly long loop turn: {:?}", loop_duration);
 543             self.poke_rust_analyzer_developer(format!(
 544                 "overly long loop turn: {:?}",
 545                 loop_duration
 546             ));
 547         }
 548         Ok(())
 549     }
 550
 551     fn on_request(&mut self, request_received: Instant, req: Request) -> Result<()> {
 552         self.register_request(&req, request_received);
 553
 554         if self.shutdown_requested {
 555             self.respond(lsp_server::Response::new_err(
 556                 req.id,
 557                 lsp_server::ErrorCode::InvalidRequest as i32,
 558                 "Shutdown already requested.".to_owned(),
 559             ));
 560
 561             return Ok(());
 562         }
 563
 564         // Avoid flashing a bunch of unresolved references during initial load.
 565         if self.workspaces.is_empty() && !self.is_quiescent() {
 566             self.respond(lsp_server::Response::new_err(
 567                 req.id,
 568                 // FIXME: i32 should impl From<ErrorCode> (from() guarantees lossless conversion)
 569                 lsp_server::ErrorCode::ContentModified as i32,
 570                 "waiting for cargo metadata or cargo check".to_owned(),
 571             ));
 572             return Ok(());
 573         }
 574
 575         RequestDispatcher { req: Some(req), global_state: self }
 576             .on_sync_mut::<lsp_ext::ReloadWorkspace>(|s, ()| {
 577                 s.fetch_workspaces_queue.request_op();
 578                 Ok(())
 579             })?
 580             .on_sync_mut::<lsp_types::request::Shutdown>(|s, ()| {
 581                 s.shutdown_requested = true;
 582                 Ok(())
 583             })?
 584             .on_sync_mut::<lsp_ext::MemoryUsage>(handlers::handle_memory_usage)?
 585             .on_sync_mut::<lsp_ext::ShuffleCrateGraph>(handlers::handle_shuffle_crate_graph)?
 586             .on_sync::<lsp_ext::JoinLines>(handlers::handle_join_lines)?
 587             .on_sync::<lsp_ext::OnEnter>(handlers::handle_on_enter)?
 588             .on_sync::<lsp_types::request::SelectionRangeRequest>(handlers::handle_selection_range)?
 589             .on_sync::<lsp_ext::MatchingBrace>(handlers::handle_matching_brace)?
 590             .on::<lsp_ext::AnalyzerStatus>(handlers::handle_analyzer_status)
 591             .on::<lsp_ext::SyntaxTree>(handlers::handle_syntax_tree)
 592             .on::<lsp_ext::ViewHir>(handlers::handle_view_hir)
 593             .on::<lsp_ext::ViewCrateGraph>(handlers::handle_view_crate_graph)
 594             .on::<lsp_ext::ViewItemTree>(handlers::handle_view_item_tree)
 595             .on::<lsp_ext::ExpandMacro>(handlers::handle_expand_macro)
 596             .on::<lsp_ext::ParentModule>(handlers::handle_parent_module)
 597             .on::<lsp_ext::Runnables>(handlers::handle_runnables)
 598             .on::<lsp_ext::RelatedTests>(handlers::handle_related_tests)
 599             .on::<lsp_ext::InlayHints>(handlers::handle_inlay_hints)
 600             .on::<lsp_ext::CodeActionRequest>(handlers::handle_code_action)
 601             .on::<lsp_ext::CodeActionResolveRequest>(handlers::handle_code_action_resolve)
 602             .on::<lsp_ext::HoverRequest>(handlers::handle_hover)
 603             .on::<lsp_ext::ExternalDocs>(handlers::handle_open_docs)
 604             .on::<lsp_ext::OpenCargoToml>(handlers::handle_open_cargo_toml)
 605             .on::<lsp_ext::MoveItem>(handlers::handle_move_item)
 606             .on::<lsp_ext::WorkspaceSymbol>(handlers::handle_workspace_symbol)
 607             .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)
 608             .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)
 609             .on::<lsp_types::request::GotoDefinition>(handlers::handle_goto_definition)
 610             .on::<lsp_types::request::GotoDeclaration>(handlers::handle_goto_declaration)
 611             .on::<lsp_types::request::GotoImplementation>(handlers::handle_goto_implementation)
 612             .on::<lsp_types::request::GotoTypeDefinition>(handlers::handle_goto_type_definition)
 613             .on::<lsp_types::request::Completion>(handlers::handle_completion)
 614             .on::<lsp_types::request::ResolveCompletionItem>(handlers::handle_completion_resolve)
 615             .on::<lsp_types::request::CodeLensRequest>(handlers::handle_code_lens)
 616             .on::<lsp_types::request::CodeLensResolve>(handlers::handle_code_lens_resolve)
 617             .on::<lsp_types::request::FoldingRangeRequest>(handlers::handle_folding_range)
 618             .on::<lsp_types::request::SignatureHelpRequest>(handlers::handle_signature_help)
 619             .on::<lsp_types::request::PrepareRenameRequest>(handlers::handle_prepare_rename)
 620             .on::<lsp_types::request::Rename>(handlers::handle_rename)
 621             .on::<lsp_types::request::References>(handlers::handle_references)
 622             .on::<lsp_types::request::Formatting>(handlers::handle_formatting)
 623             .on::<lsp_types::request::RangeFormatting>(handlers::handle_range_formatting)
 624             .on::<lsp_types::request::DocumentHighlightRequest>(handlers::handle_document_highlight)
 625             .on::<lsp_types::request::CallHierarchyPrepare>(handlers::handle_call_hierarchy_prepare)
 626             .on::<lsp_types::request::CallHierarchyIncomingCalls>(
 627                 handlers::handle_call_hierarchy_incoming,
 628             )
 629             .on::<lsp_types::request::CallHierarchyOutgoingCalls>(
 630                 handlers::handle_call_hierarchy_outgoing,
 631             )
 632             .on::<lsp_types::request::SemanticTokensFullRequest>(
 633                 handlers::handle_semantic_tokens_full,
 634             )
 635             .on::<lsp_types::request::SemanticTokensFullDeltaRequest>(
 636                 handlers::handle_semantic_tokens_full_delta,
 637             )
 638             .on::<lsp_types::request::SemanticTokensRangeRequest>(
 639                 handlers::handle_semantic_tokens_range,
 640             )
 641             .on::<lsp_types::request::WillRenameFiles>(handlers::handle_will_rename_files)
 642             .on::<lsp_ext::Ssr>(handlers::handle_ssr)
 643             .finish();
 644         Ok(())
 645     }
 646     fn on_notification(&mut self, not: Notification) -> Result<()> {
 647         NotificationDispatcher { not: Some(not), global_state: self }
 648             .on::<lsp_types::notification::Cancel>(|this, params| {
 649                 let id: lsp_server::RequestId = match params.id {
 650                     lsp_types::NumberOrString::Number(id) => id.into(),
 651                     lsp_types::NumberOrString::String(id) => id.into(),
 652                 };
 653                 this.cancel(id);
 654                 Ok(())
 655             })?
 656             .on::<lsp_types::notification::WorkDoneProgressCancel>(|_this, _params| {
 657                 // Just ignore this. It is OK to continue sending progress
 658                 // notifications for this token, as the client can't know when
 659                 // we accepted notification.
 660                 Ok(())
 661             })?
 662             .on::<lsp_types::notification::DidOpenTextDocument>(|this, params| {
 663                 if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
 664                     if this
 665                         .mem_docs
 666                         .insert(path.clone(), DocumentData::new(params.text_document.version))
 667                         .is_err()
 668                     {
 669                         tracing::error!("duplicate DidOpenTextDocument: {}", path)
 670                     }
 671                     this.vfs
 672                         .write()
 673                         .0
 674                         .set_file_contents(path, Some(params.text_document.text.into_bytes()));
 675                 }
 676                 Ok(())
 677             })?
 678             .on::<lsp_types::notification::DidChangeTextDocument>(|this, params| {
 679                 if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
 680                     match this.mem_docs.get_mut(&path) {
 681                         Some(doc) => {
 682                             // The version passed in DidChangeTextDocument is the version after all edits are applied
 683                             // so we should apply it before the vfs is notified.
 684                             doc.version = params.text_document.version;
 685                         }
 686                         None => {
 687                             tracing::error!("unexpected DidChangeTextDocument: {}; send DidOpenTextDocument first", path);
 688                             return Ok(());
 689                         }
 690                     };
 691
 692                     let vfs = &mut this.vfs.write().0;
 693                     let file_id = vfs.file_id(&path).unwrap();
 694                     let mut text = String::from_utf8(vfs.file_contents(file_id).to_vec()).unwrap();
 695                     apply_document_changes(&mut text, params.content_changes);
 696
 697                     vfs.set_file_contents(path, Some(text.into_bytes()));
 698                 }
 699                 Ok(())
 700             })?
 701             .on::<lsp_types::notification::DidCloseTextDocument>(|this, params| {
 702                 if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
 703                     if this.mem_docs.remove(&path).is_err() {
 704                         tracing::error!("orphan DidCloseTextDocument: {}", path);
 705                     }
 706
 707                     this.semantic_tokens_cache.lock().remove(&params.text_document.uri);
 708
 709                     if let Some(path) = path.as_path() {
 710                         this.loader.handle.invalidate(path.to_path_buf());
 711                     }
 712                 }
 713                 Ok(())
 714             })?
 715             .on::<lsp_types::notification::DidSaveTextDocument>(|this, params| {
 716                 for flycheck in &this.flycheck {
 717                     flycheck.update();
 718                 }
 719                 if let Ok(abs_path) = from_proto::abs_path(&params.text_document.uri) {
 720                     if reload::should_refresh_for_change(&abs_path, ChangeKind::Modify) {
 721                         this.fetch_workspaces_queue.request_op();
 722                     }
 723                 }
 724                 Ok(())
 725             })?
 726             .on::<lsp_types::notification::DidChangeConfiguration>(|this, _params| {
 727                 // As stated in https://github.com/microsoft/language-server-protocol/issues/676,
 728                 // this notification's parameters should be ignored and the actual config queried separately.
 729                 this.send_request::<lsp_types::request::WorkspaceConfiguration>(
 730                     lsp_types::ConfigurationParams {
 731                         items: vec![lsp_types::ConfigurationItem {
 732                             scope_uri: None,
 733                             section: Some("rust-analyzer".to_string()),
 734                         }],
 735                     },
 736                     |this, resp| {
 737                         tracing::debug!("config update response: '{:?}", resp);
 738                         let lsp_server::Response { error, result, .. } = resp;
 739
 740                         match (error, result) {
 741                             (Some(err), _) => {
 742                                 tracing::error!("failed to fetch the server settings: {:?}", err)
 743                             }
 744                             (None, Some(mut configs)) => {
 745                                 if let Some(json) = configs.get_mut(0) {
 746                                     // Note that json can be null according to the spec if the client can't
 747                                     // provide a configuration. This is handled in Config::update below.
 748                                     let mut config = Config::clone(&*this.config);
 749                                     if let Err(errors) = config.update(json.take()) {
 750                                         let errors = errors
 751                                             .iter()
 752                                             .format_with("\n", |(key, e),f| {
 753                                                 f(key)?;
 754                                                 f(&": ")?;
 755                                                 f(e)
 756                                             });
 757                                         let msg= format!("Failed to deserialize config key(s):\n{}", errors);
 758                                         this.show_message(lsp_types::MessageType::WARNING, msg);
 759                                     }
 760                                     this.update_configuration(config);
 761                                 }
 762                             }
 763                             (None, None) => tracing::error!(
 764                                 "received empty server settings response from the client"
 765                             ),
 766                         }
 767                     },
 768                 );
 769
 770                 Ok(())
 771             })?
 772             .on::<lsp_types::notification::DidChangeWatchedFiles>(|this, params| {
 773                 for change in params.changes {
 774                     if let Ok(path) = from_proto::abs_path(&change.uri) {
 775                         this.loader.handle.invalidate(path);
 776                     }
 777                 }
 778                 Ok(())
 779             })?
 780             .finish();
 781         Ok(())
 782     }
 783
 784     fn update_diagnostics(&mut self) {
 785         let subscriptions = self
 786             .mem_docs
 787             .iter()
 788             .map(|path| self.vfs.read().0.file_id(path).unwrap())
 789             .collect::<Vec<_>>();
 790
 791         tracing::trace!("updating notifications for {:?}", subscriptions);
 792
 793         let snapshot = self.snapshot();
 794         self.task_pool.handle.spawn(move || {
 795             let diagnostics = subscriptions
 796                 .into_iter()
 797                 .filter_map(|file_id| {
 798                     handlers::publish_diagnostics(&snapshot, file_id)
 799                         .map_err(|err| {
 800                             if !is_cancelled(&*err) {
 801                                 tracing::error!("failed to compute diagnostics: {:?}", err);
 802                             }
 803                         })
 804                         .ok()
 805                         .map(|diags| (file_id, diags))
 806                 })
 807                 .collect::<Vec<_>>();
 808             Task::Diagnostics(diagnostics)
 809         })
 810     }
 811 }