crates/rust-analyzer/src/main_loop.rs

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