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