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::{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_request();
 156         self.fetch_workspaces_if_needed();
 157
 158         while let Some(event) = self.next_event(&inbox) {
 159             if let Event::Lsp(lsp_server::Message::Notification(not)) = &event {
 160                 if not.method == lsp_types::notification::Exit::METHOD {
 161                     return Ok(());
 162                 }
 163             }
 164             self.handle_event(event)?
 165         }
 166
 167         Err("client exited without proper shutdown sequence")?
 168     }
 169
 170     fn next_event(&self, inbox: &Receiver<lsp_server::Message>) -> Option<Event> {
 171         select! {
 172             recv(inbox) -> msg =>
 173                 msg.ok().map(Event::Lsp),
 174
 175             recv(self.task_pool.receiver) -> task =>
 176                 Some(Event::Task(task.unwrap())),
 177
 178             recv(self.loader.receiver) -> task =>
 179                 Some(Event::Vfs(task.unwrap())),
 180
 181             recv(self.flycheck_receiver) -> task =>
 182                 Some(Event::Flycheck(task.unwrap())),
 183         }
 184     }
 185
 186     fn handle_event(&mut self, event: Event) -> Result<()> {
 187         let loop_start = Instant::now();
 188         // NOTE: don't count blocking select! call as a loop-turn time
 189         let _p = profile::span("GlobalState::handle_event");
 190
 191         tracing::info!("handle_event({:?})", event);
 192         let task_queue_len = self.task_pool.handle.len();
 193         if task_queue_len > 0 {
 194             tracing::info!("task queue len: {}", task_queue_len);
 195         }
 196
 197         let was_quiescent = self.is_quiescent();
 198         match event {
 199             Event::Lsp(msg) => match msg {
 200                 lsp_server::Message::Request(req) => self.on_request(loop_start, req)?,
 201                 lsp_server::Message::Notification(not) => {
 202                     self.on_notification(not)?;
 203                 }
 204                 lsp_server::Message::Response(resp) => self.complete_request(resp),
 205             },
 206             Event::Task(mut task) => {
 207                 let _p = profile::span("GlobalState::handle_event/task");
 208                 let mut prime_caches_progress = Vec::new();
 209                 loop {
 210                     match task {
 211                         Task::Response(response) => self.respond(response),
 212                         Task::Diagnostics(diagnostics_per_file) => {
 213                             for (file_id, diagnostics) in diagnostics_per_file {
 214                                 self.diagnostics.set_native_diagnostics(file_id, diagnostics)
 215                             }
 216                         }
 217                         Task::PrimeCaches(progress) => match progress {
 218                             PrimeCachesProgress::Begin => prime_caches_progress.push(progress),
 219                             PrimeCachesProgress::Report(_) => {
 220                                 match prime_caches_progress.last_mut() {
 221                                     Some(last @ PrimeCachesProgress::Report(_)) => {
 222                                         // Coalesce subsequent update events.
 223                                         *last = progress;
 224                                     }
 225                                     _ => prime_caches_progress.push(progress),
 226                                 }
 227                             }
 228                             PrimeCachesProgress::End { .. } => prime_caches_progress.push(progress),
 229                         },
 230                         Task::FetchWorkspace(progress) => {
 231                             let (state, msg) = match progress {
 232                                 ProjectWorkspaceProgress::Begin => (Progress::Begin, None),
 233                                 ProjectWorkspaceProgress::Report(msg) => {
 234                                     (Progress::Report, Some(msg))
 235                                 }
 236                                 ProjectWorkspaceProgress::End(workspaces) => {
 237                                     self.fetch_workspaces_completed(workspaces);
 238
 239                                     let old = Arc::clone(&self.workspaces);
 240                                     self.switch_workspaces();
 241                                     let workspaces_updated = !Arc::ptr_eq(&old, &self.workspaces);
 242
 243                                     if self.config.run_build_scripts() && workspaces_updated {
 244                                         self.fetch_build_data_request()
 245                                     }
 246
 247                                     (Progress::End, None)
 248                                 }
 249                             };
 250
 251                             self.report_progress("Fetching", state, msg, None);
 252                         }
 253                         Task::FetchBuildData(progress) => {
 254                             let (state, msg) = match progress {
 255                                 BuildDataProgress::Begin => (Some(Progress::Begin), None),
 256                                 BuildDataProgress::Report(msg) => {
 257                                     (Some(Progress::Report), Some(msg))
 258                                 }
 259                                 BuildDataProgress::End(build_data_result) => {
 260                                     self.fetch_build_data_completed(build_data_result);
 261
 262                                     self.switch_workspaces();
 263
 264                                     (Some(Progress::End), None)
 265                                 }
 266                             };
 267
 268                             if let Some(state) = state {
 269                                 self.report_progress("Loading", state, msg, None);
 270                             }
 271                         }
 272                     }
 273
 274                     // Coalesce multiple task events into one loop turn
 275                     task = match self.task_pool.receiver.try_recv() {
 276                         Ok(task) => task,
 277                         Err(_) => break,
 278                     };
 279                 }
 280
 281                 for progress in prime_caches_progress {
 282                     let (state, message, fraction);
 283                     match progress {
 284                         PrimeCachesProgress::Begin => {
 285                             state = Progress::Begin;
 286                             message = None;
 287                             fraction = 0.0;
 288                         }
 289                         PrimeCachesProgress::Report(report) => {
 290                             state = Progress::Report;
 291                             message = Some(format!(
 292                                 "{}/{} ({})",
 293                                 report.n_done, report.n_total, report.on_crate
 294                             ));
 295                             fraction = Progress::fraction(report.n_done, report.n_total);
 296                         }
 297                         PrimeCachesProgress::End { cancelled: _ } => {
 298                             state = Progress::End;
 299                             message = None;
 300                             fraction = 1.0;
 301
 302                             self.prime_caches_queue.op_completed(());
 303                         }
 304                     };
 305
 306                     self.report_progress("Indexing", state, message, Some(fraction));
 307                 }
 308             }
 309             Event::Vfs(mut task) => {
 310                 let _p = profile::span("GlobalState::handle_event/vfs");
 311                 loop {
 312                     match task {
 313                         vfs::loader::Message::Loaded { files } => {
 314                             let vfs = &mut self.vfs.write().0;
 315                             for (path, contents) in files {
 316                                 let path = VfsPath::from(path);
 317                                 if !self.mem_docs.contains(&path) {
 318                                     vfs.set_file_contents(path, contents);
 319                                 }
 320                             }
 321                         }
 322                         vfs::loader::Message::Progress { n_total, n_done, config_version } => {
 323                             always!(config_version <= self.vfs_config_version);
 324
 325                             self.vfs_progress_config_version = config_version;
 326                             self.vfs_progress_n_total = n_total;
 327                             self.vfs_progress_n_done = n_done;
 328
 329                             let state = if n_done == 0 {
 330                                 Progress::Begin
 331                             } else if n_done < n_total {
 332                                 Progress::Report
 333                             } else {
 334                                 assert_eq!(n_done, n_total);
 335                                 Progress::End
 336                             };
 337                             self.report_progress(
 338                                 "Roots Scanned",
 339                                 state,
 340                                 Some(format!("{}/{}", n_done, n_total)),
 341                                 Some(Progress::fraction(n_done, n_total)),
 342                             )
 343                         }
 344                     }
 345                     // Coalesce many VFS event into a single loop turn
 346                     task = match self.loader.receiver.try_recv() {
 347                         Ok(task) => task,
 348                         Err(_) => break,
 349                     }
 350                 }
 351             }
 352             Event::Flycheck(mut task) => {
 353                 let _p = profile::span("GlobalState::handle_event/flycheck");
 354                 loop {
 355                     match task {
 356                         flycheck::Message::AddDiagnostic { workspace_root, diagnostic } => {
 357                             let diagnostics =
 358                                 crate::diagnostics::to_proto::map_rust_diagnostic_to_lsp(
 359                                     &self.config.diagnostics_map(),
 360                                     &diagnostic,
 361                                     &workspace_root,
 362                                 );
 363                             for diag in diagnostics {
 364                                 match url_to_file_id(&self.vfs.read().0, &diag.url) {
 365                                     Ok(file_id) => self.diagnostics.add_check_diagnostic(
 366                                         file_id,
 367                                         diag.diagnostic,
 368                                         diag.fixes,
 369                                     ),
 370                                     Err(err) => {
 371                                         tracing::error!(
 372                                             "File with cargo diagnostic not found in VFS: {}",
 373                                             err
 374                                         );
 375                                     }
 376                                 };
 377                             }
 378                         }
 379
 380                         flycheck::Message::Progress { id, progress } => {
 381                             let (state, message) = match progress {
 382                                 flycheck::Progress::DidStart => {
 383                                     self.diagnostics.clear_check();
 384                                     (Progress::Begin, None)
 385                                 }
 386                                 flycheck::Progress::DidCheckCrate(target) => {
 387                                     (Progress::Report, Some(target))
 388                                 }
 389                                 flycheck::Progress::DidCancel => (Progress::End, None),
 390                                 flycheck::Progress::DidFinish(result) => {
 391                                     if let Err(err) = result {
 392                                         tracing::error!("cargo check failed: {}", err)
 393                                     }
 394                                     (Progress::End, None)
 395                                 }
 396                             };
 397
 398                             // When we're running multiple flychecks, we have to include a disambiguator in
 399                             // the title, or the editor complains. Note that this is a user-facing string.
 400                             let title = if self.flycheck.len() == 1 {
 401                                 "cargo check".to_string()
 402                             } else {
 403                                 format!("cargo check (#{})", id + 1)
 404                             };
 405                             self.report_progress(&title, state, message, None);
 406                         }
 407                     }
 408                     // Coalesce many flycheck updates into a single loop turn
 409                     task = match self.flycheck_receiver.try_recv() {
 410                         Ok(task) => task,
 411                         Err(_) => break,
 412                     }
 413                 }
 414             }
 415         }
 416
 417         let state_changed = self.process_changes();
 418         let memdocs_added_or_removed = self.mem_docs.take_changes();
 419
 420         if self.is_quiescent() {
 421             if !was_quiescent {
 422                 for flycheck in &self.flycheck {
 423                     flycheck.update();
 424                 }
 425             }
 426
 427             if !was_quiescent || state_changed {
 428                 // Ensure that only one cache priming task can run at a time
 429                 self.prime_caches_queue.request_op();
 430                 if self.prime_caches_queue.should_start_op() {
 431                     self.task_pool.handle.spawn_with_sender({
 432                         let analysis = self.snapshot().analysis;
 433                         move |sender| {
 434                             sender.send(Task::PrimeCaches(PrimeCachesProgress::Begin)).unwrap();
 435                             let res = analysis.prime_caches(|progress| {
 436                                 let report = PrimeCachesProgress::Report(progress);
 437                                 sender.send(Task::PrimeCaches(report)).unwrap();
 438                             });
 439                             sender
 440                                 .send(Task::PrimeCaches(PrimeCachesProgress::End {
 441                                     cancelled: res.is_err(),
 442                                 }))
 443                                 .unwrap();
 444                         }
 445                     });
 446                 }
 447
 448                 // Refresh semantic tokens if the client supports it.
 449                 if self.config.semantic_tokens_refresh() {
 450                     self.semantic_tokens_cache.lock().clear();
 451                     self.send_request::<lsp_types::request::SemanticTokensRefesh>((), |_, _| ());
 452                 }
 453
 454                 // Refresh code lens if the client supports it.
 455                 if self.config.code_lens_refresh() {
 456                     self.send_request::<lsp_types::request::CodeLensRefresh>((), |_, _| ());
 457                 }
 458             }
 459
 460             if !was_quiescent || state_changed || memdocs_added_or_removed {
 461                 if self.config.publish_diagnostics() {
 462                     self.update_diagnostics()
 463                 }
 464             }
 465         }
 466
 467         if let Some(diagnostic_changes) = self.diagnostics.take_changes() {
 468             for file_id in diagnostic_changes {
 469                 let db = self.analysis_host.raw_database();
 470                 let source_root = db.file_source_root(file_id);
 471                 if db.source_root(source_root).is_library {
 472                     // Only publish diagnostics for files in the workspace, not from crates.io deps
 473                     // or the sysroot.
 474                     // While theoretically these should never have errors, we have quite a few false
 475                     // positives particularly in the stdlib, and those diagnostics would stay around
 476                     // forever if we emitted them here.
 477                     continue;
 478                 }
 479
 480                 let url = file_id_to_url(&self.vfs.read().0, file_id);
 481                 let diagnostics = self.diagnostics.diagnostics_for(file_id).cloned().collect();
 482                 let version = from_proto::vfs_path(&url)
 483                     .map(|path| self.mem_docs.get(&path).map(|it| it.version))
 484                     .unwrap_or_default();
 485
 486                 self.send_notification::<lsp_types::notification::PublishDiagnostics>(
 487                     lsp_types::PublishDiagnosticsParams { uri: url, diagnostics, version },
 488                 );
 489             }
 490         }
 491
 492         if self.config.cargo_autoreload() {
 493             self.fetch_workspaces_if_needed();
 494         }
 495         self.fetch_build_data_if_needed();
 496
 497         self.report_new_status_if_needed();
 498
 499         let loop_duration = loop_start.elapsed();
 500         if loop_duration > Duration::from_millis(100) {
 501             tracing::warn!("overly long loop turn: {:?}", loop_duration);
 502             self.poke_rust_analyzer_developer(format!(
 503                 "overly long loop turn: {:?}",
 504                 loop_duration
 505             ));
 506         }
 507         Ok(())
 508     }
 509
 510     fn on_request(&mut self, request_received: Instant, req: Request) -> Result<()> {
 511         self.register_request(&req, request_received);
 512
 513         if self.shutdown_requested {
 514             self.respond(lsp_server::Response::new_err(
 515                 req.id,
 516                 lsp_server::ErrorCode::InvalidRequest as i32,
 517                 "Shutdown already requested.".to_owned(),
 518             ));
 519
 520             return Ok(());
 521         }
 522
 523         // Avoid flashing a bunch of unresolved references during initial load.
 524         if self.workspaces.is_empty() && !self.is_quiescent() {
 525             self.respond(lsp_server::Response::new_err(
 526                 req.id,
 527                 // FIXME: i32 should impl From<ErrorCode> (from() guarantees lossless conversion)
 528                 lsp_server::ErrorCode::ContentModified as i32,
 529                 "waiting for cargo metadata or cargo check".to_owned(),
 530             ));
 531             return Ok(());
 532         }
 533
 534         RequestDispatcher { req: Some(req), global_state: self }
 535             .on_sync_mut::<lsp_ext::ReloadWorkspace>(|s, ()| {
 536                 s.fetch_workspaces_request();
 537                 s.fetch_workspaces_if_needed();
 538                 Ok(())
 539             })?
 540             .on_sync_mut::<lsp_types::request::Shutdown>(|s, ()| {
 541                 s.shutdown_requested = true;
 542                 Ok(())
 543             })?
 544             .on_sync_mut::<lsp_ext::MemoryUsage>(|s, p| handlers::handle_memory_usage(s, p))?
 545             .on_sync::<lsp_ext::JoinLines>(handlers::handle_join_lines)?
 546             .on_sync::<lsp_ext::OnEnter>(handlers::handle_on_enter)?
 547             .on_sync::<lsp_types::request::SelectionRangeRequest>(handlers::handle_selection_range)?
 548             .on_sync::<lsp_ext::MatchingBrace>(handlers::handle_matching_brace)?
 549             .on::<lsp_ext::AnalyzerStatus>(handlers::handle_analyzer_status)
 550             .on::<lsp_ext::SyntaxTree>(handlers::handle_syntax_tree)
 551             .on::<lsp_ext::ViewHir>(handlers::handle_view_hir)
 552             .on::<lsp_ext::ViewCrateGraph>(handlers::handle_view_crate_graph)
 553             .on::<lsp_ext::ViewItemTree>(handlers::handle_view_item_tree)
 554             .on::<lsp_ext::ExpandMacro>(handlers::handle_expand_macro)
 555             .on::<lsp_ext::ParentModule>(handlers::handle_parent_module)
 556             .on::<lsp_ext::Runnables>(handlers::handle_runnables)
 557             .on::<lsp_ext::RelatedTests>(handlers::handle_related_tests)
 558             .on::<lsp_ext::InlayHints>(handlers::handle_inlay_hints)
 559             .on::<lsp_ext::CodeActionRequest>(handlers::handle_code_action)
 560             .on::<lsp_ext::CodeActionResolveRequest>(handlers::handle_code_action_resolve)
 561             .on::<lsp_ext::HoverRequest>(handlers::handle_hover)
 562             .on::<lsp_ext::ExternalDocs>(handlers::handle_open_docs)
 563             .on::<lsp_ext::OpenCargoToml>(handlers::handle_open_cargo_toml)
 564             .on::<lsp_ext::MoveItem>(handlers::handle_move_item)
 565             .on::<lsp_ext::WorkspaceSymbol>(handlers::handle_workspace_symbol)
 566             .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)
 567             .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)
 568             .on::<lsp_types::request::GotoDefinition>(handlers::handle_goto_definition)
 569             .on::<lsp_types::request::GotoDeclaration>(handlers::handle_goto_declaration)
 570             .on::<lsp_types::request::GotoImplementation>(handlers::handle_goto_implementation)
 571             .on::<lsp_types::request::GotoTypeDefinition>(handlers::handle_goto_type_definition)
 572             .on::<lsp_types::request::Completion>(handlers::handle_completion)
 573             .on::<lsp_types::request::ResolveCompletionItem>(handlers::handle_completion_resolve)
 574             .on::<lsp_types::request::CodeLensRequest>(handlers::handle_code_lens)
 575             .on::<lsp_types::request::CodeLensResolve>(handlers::handle_code_lens_resolve)
 576             .on::<lsp_types::request::FoldingRangeRequest>(handlers::handle_folding_range)
 577             .on::<lsp_types::request::SignatureHelpRequest>(handlers::handle_signature_help)
 578             .on::<lsp_types::request::PrepareRenameRequest>(handlers::handle_prepare_rename)
 579             .on::<lsp_types::request::Rename>(handlers::handle_rename)
 580             .on::<lsp_types::request::References>(handlers::handle_references)
 581             .on::<lsp_types::request::Formatting>(handlers::handle_formatting)
 582             .on::<lsp_types::request::RangeFormatting>(handlers::handle_range_formatting)
 583             .on::<lsp_types::request::DocumentHighlightRequest>(handlers::handle_document_highlight)
 584             .on::<lsp_types::request::CallHierarchyPrepare>(handlers::handle_call_hierarchy_prepare)
 585             .on::<lsp_types::request::CallHierarchyIncomingCalls>(
 586                 handlers::handle_call_hierarchy_incoming,
 587             )
 588             .on::<lsp_types::request::CallHierarchyOutgoingCalls>(
 589                 handlers::handle_call_hierarchy_outgoing,
 590             )
 591             .on::<lsp_types::request::SemanticTokensFullRequest>(
 592                 handlers::handle_semantic_tokens_full,
 593             )
 594             .on::<lsp_types::request::SemanticTokensFullDeltaRequest>(
 595                 handlers::handle_semantic_tokens_full_delta,
 596             )
 597             .on::<lsp_types::request::SemanticTokensRangeRequest>(
 598                 handlers::handle_semantic_tokens_range,
 599             )
 600             .on::<lsp_types::request::WillRenameFiles>(handlers::handle_will_rename_files)
 601             .on::<lsp_ext::Ssr>(handlers::handle_ssr)
 602             .finish();
 603         Ok(())
 604     }
 605     fn on_notification(&mut self, not: Notification) -> Result<()> {
 606         NotificationDispatcher { not: Some(not), global_state: self }
 607             .on::<lsp_types::notification::Cancel>(|this, params| {
 608                 let id: lsp_server::RequestId = match params.id {
 609                     lsp_types::NumberOrString::Number(id) => id.into(),
 610                     lsp_types::NumberOrString::String(id) => id.into(),
 611                 };
 612                 this.cancel(id);
 613                 Ok(())
 614             })?
 615             .on::<lsp_types::notification::WorkDoneProgressCancel>(|_this, _params| {
 616                 // Just ignore this. It is OK to continue sending progress
 617                 // notifications for this token, as the client can't know when
 618                 // we accepted notification.
 619                 Ok(())
 620             })?
 621             .on::<lsp_types::notification::DidOpenTextDocument>(|this, params| {
 622                 if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
 623                     if this
 624                         .mem_docs
 625                         .insert(path.clone(), DocumentData::new(params.text_document.version))
 626                         .is_err()
 627                     {
 628                         tracing::error!("duplicate DidOpenTextDocument: {}", path)
 629                     }
 630                     this.vfs
 631                         .write()
 632                         .0
 633                         .set_file_contents(path, Some(params.text_document.text.into_bytes()));
 634                 }
 635                 Ok(())
 636             })?
 637             .on::<lsp_types::notification::DidChangeTextDocument>(|this, params| {
 638                 if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
 639                     match this.mem_docs.get_mut(&path) {
 640                         Some(doc) => {
 641                             // The version passed in DidChangeTextDocument is the version after all edits are applied
 642                             // so we should apply it before the vfs is notified.
 643                             doc.version = params.text_document.version;
 644                         }
 645                         None => {
 646                             tracing::error!("expected DidChangeTextDocument: {}", path);
 647                             return Ok(());
 648                         }
 649                     };
 650
 651                     let vfs = &mut this.vfs.write().0;
 652                     let file_id = vfs.file_id(&path).unwrap();
 653                     let mut text = String::from_utf8(vfs.file_contents(file_id).to_vec()).unwrap();
 654                     apply_document_changes(&mut text, params.content_changes);
 655
 656                     vfs.set_file_contents(path, Some(text.into_bytes()));
 657                 }
 658                 Ok(())
 659             })?
 660             .on::<lsp_types::notification::DidCloseTextDocument>(|this, params| {
 661                 if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
 662                     if this.mem_docs.remove(&path).is_err() {
 663                         tracing::error!("orphan DidCloseTextDocument: {}", path);
 664                     }
 665
 666                     this.semantic_tokens_cache.lock().remove(&params.text_document.uri);
 667
 668                     if let Some(path) = path.as_path() {
 669                         this.loader.handle.invalidate(path.to_path_buf());
 670                     }
 671                 }
 672                 Ok(())
 673             })?
 674             .on::<lsp_types::notification::DidSaveTextDocument>(|this, params| {
 675                 for flycheck in &this.flycheck {
 676                     flycheck.update();
 677                 }
 678                 if let Ok(abs_path) = from_proto::abs_path(&params.text_document.uri) {
 679                     this.maybe_refresh(&[(abs_path, ChangeKind::Modify)]);
 680                 }
 681                 Ok(())
 682             })?
 683             .on::<lsp_types::notification::DidChangeConfiguration>(|this, _params| {
 684                 // As stated in https://github.com/microsoft/language-server-protocol/issues/676,
 685                 // this notification's parameters should be ignored and the actual config queried separately.
 686                 this.send_request::<lsp_types::request::WorkspaceConfiguration>(
 687                     lsp_types::ConfigurationParams {
 688                         items: vec![lsp_types::ConfigurationItem {
 689                             scope_uri: None,
 690                             section: Some("rust-analyzer".to_string()),
 691                         }],
 692                     },
 693                     |this, resp| {
 694                         tracing::debug!("config update response: '{:?}", resp);
 695                         let lsp_server::Response { error, result, .. } = resp;
 696
 697                         match (error, result) {
 698                             (Some(err), _) => {
 699                                 tracing::error!("failed to fetch the server settings: {:?}", err)
 700                             }
 701                             (None, Some(mut configs)) => {
 702                                 if let Some(json) = configs.get_mut(0) {
 703                                     // Note that json can be null according to the spec if the client can't
 704                                     // provide a configuration. This is handled in Config::update below.
 705                                     let mut config = Config::clone(&*this.config);
 706                                     config.update(json.take());
 707                                     this.update_configuration(config);
 708                                 }
 709                             }
 710                             (None, None) => tracing::error!(
 711                                 "received empty server settings response from the client"
 712                             ),
 713                         }
 714                     },
 715                 );
 716
 717                 Ok(())
 718             })?
 719             .on::<lsp_types::notification::DidChangeWatchedFiles>(|this, params| {
 720                 for change in params.changes {
 721                     if let Ok(path) = from_proto::abs_path(&change.uri) {
 722                         this.loader.handle.invalidate(path);
 723                     }
 724                 }
 725                 Ok(())
 726             })?
 727             .finish();
 728         Ok(())
 729     }
 730
 731     fn update_diagnostics(&mut self) {
 732         let subscriptions = self
 733             .mem_docs
 734             .iter()
 735             .map(|path| self.vfs.read().0.file_id(path).unwrap())
 736             .collect::<Vec<_>>();
 737
 738         tracing::trace!("updating notifications for {:?}", subscriptions);
 739
 740         let snapshot = self.snapshot();
 741         self.task_pool.handle.spawn(move || {
 742             let diagnostics = subscriptions
 743                 .into_iter()
 744                 .filter_map(|file_id| {
 745                     handlers::publish_diagnostics(&snapshot, file_id)
 746                         .map_err(|err| {
 747                             if !is_cancelled(&*err) {
 748                                 tracing::error!("failed to compute diagnostics: {:?}", err);
 749                             }
 750                             ()
 751                         })
 752                         .ok()
 753                         .map(|diags| (file_id, diags))
 754                 })
 755                 .collect::<Vec<_>>();
 756             Task::Diagnostics(diagnostics)
 757         })
 758     }
 759 }