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