gopls/internal/lsp: remove the experimentalWatchedFileDelay setting

See the associated issue for more details.

Fixes golang/go#55332

Change-Id: I062423c090838c87dbb0c2d21ab448f6c72399c6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/462496
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

gopls/doc/settings.md

@@ -358,23 +358,6 @@ This option must be set to a valid duration string, for example `"250ms"`.
 
 Default: `"250ms"`.
 
-##### **experimentalWatchedFileDelay** *time.Duration*
-
-**This setting is experimental and may be deleted.**
-
-experimentalWatchedFileDelay controls the amount of time that gopls waits
-for additional workspace/didChangeWatchedFiles notifications to arrive,
-before processing all such notifications in a single batch. This is
-intended for use by LSP clients that don't support their own batching of
-file system notifications.
-
-This option must be set to a valid duration string, for example `"100ms"`.
-
-Deprecated: this setting is deprecated and will be removed in a future
-version of gopls (https://go.dev/issue/55332)
-
-Default: `"0s"`.
-
 #### Documentation
 
 ##### **hoverKind** *enum*

gopls/internal/lsp/server.go

@@ -33,7 +33,6 @@ func NewServer(session *cache.Session, client protocol.ClientCloser) *Server {
  diagnosticsSema: make(chan struct{}, concurrentAnalyses),
  progress: progress.NewTracker(client),
  diagDebouncer: newDebouncer(),
- watchedFileDebouncer: newDebouncer(),
  }
 }
 
@@ -106,22 +105,12 @@ type Server struct {
  // diagDebouncer is used for debouncing diagnostics.
  diagDebouncer *debouncer
 
- // watchedFileDebouncer is used for batching didChangeWatchedFiles notifications.
- watchedFileDebouncer *debouncer
- fileChangeMu sync.Mutex
- pendingOnDiskChanges []*pendingModificationSet
-
  // When the workspace fails to load, we show its status through a progress
  // report with an error message.
  criticalErrorStatusMu sync.Mutex
  criticalErrorStatus *progress.WorkDone
 }
 
-type pendingModificationSet struct {
- diagnoseDone chan struct{}
- changes []source.FileModification
-}
-
 func (s *Server) workDoneProgressCancel(ctx context.Context, params *protocol.WorkDoneProgressCancelParams) error {
  return s.progress.Cancel(params.Token)
 }

gopls/internal/lsp/source/options.go

@@ -434,18 +434,6 @@ type DiagnosticOptions struct {
  //
  // This option must be set to a valid duration string, for example `"250ms"`.
  DiagnosticsDelay time.Duration `status:"advanced"`
-
- // ExperimentalWatchedFileDelay controls the amount of time that gopls waits
- // for additional workspace/didChangeWatchedFiles notifications to arrive,
- // before processing all such notifications in a single batch. This is
- // intended for use by LSP clients that don't support their own batching of
- // file system notifications.
- //
- // This option must be set to a valid duration string, for example `"100ms"`.
- //
- // Deprecated: this setting is deprecated and will be removed in a future
- // version of gopls (https://go.dev/issue/55332)
- ExperimentalWatchedFileDelay time.Duration `status:"experimental"`
 }
 
 type InlayHintOptions struct {
@@ -1120,10 +1108,7 @@ func (o *Options) set(name string, value interface{}, seen map[string]struct{})
  result.setDuration(&o.DiagnosticsDelay)
 
  case "experimentalWatchedFileDelay":
- const msg = "experimentalWatchedFileDelay is deprecated, and will " +
- "be removed in a future version of gopls (https://go.dev/issue/55332)"
- result.softErrorf(msg)
- result.setDuration(&o.ExperimentalWatchedFileDelay)
+ result.deprecated("")
 
  case "experimentalPackageCacheKey":
  result.setBool(&o.ExperimentalPackageCacheKey)

gopls/internal/lsp/text_synchronization.go

@@ -10,14 +10,11 @@ import (
  "errors"
  "fmt"
  "path/filepath"
- "time"
 
  "golang.org/x/tools/gopls/internal/lsp/protocol"
  "golang.org/x/tools/gopls/internal/lsp/source"
  "golang.org/x/tools/gopls/internal/span"
- "golang.org/x/tools/internal/event"
  "golang.org/x/tools/internal/jsonrpc2"
- "golang.org/x/tools/internal/xcontext"
 )
 
 // ModificationSource identifies the originating cause of a file modification.
@@ -220,59 +217,7 @@ func (s *Server) didModifyFiles(ctx context.Context, modifications []source.File
  }
 
  onDisk := cause == FromDidChangeWatchedFiles
- delay := s.session.Options().ExperimentalWatchedFileDelay
- s.fileChangeMu.Lock()
- defer s.fileChangeMu.Unlock()
- if !onDisk || delay == 0 {
- // No delay: process the modifications immediately.
- return s.processModifications(ctx, modifications, onDisk, diagnoseDone)
- }
- // Debounce and batch up pending modifications from watched files.
- pending := &pendingModificationSet{
- diagnoseDone: diagnoseDone,
- changes: modifications,
- }
- // Invariant: changes appended to s.pendingOnDiskChanges are eventually
- // handled in the order they arrive. This guarantee is only partially
- // enforced here. Specifically:
- // 1. s.fileChangesMu ensures that the append below happens in the order
- // notifications were received, so that the changes within each batch are
- // ordered properly.
- // 2. The debounced func below holds s.fileChangesMu while processing all
- // changes in s.pendingOnDiskChanges, ensuring that no batches are
- // processed out of order.
- // 3. Session.ExpandModificationsToDirectories and Session.DidModifyFiles
- // process changes in order.
- s.pendingOnDiskChanges = append(s.pendingOnDiskChanges, pending)
- ctx = xcontext.Detach(ctx)
- okc := s.watchedFileDebouncer.debounce("", 0, time.After(delay))
- go func() {
- if ok := <-okc; !ok {
- return
- }
- s.fileChangeMu.Lock()
- var allChanges []source.FileModification
- // For accurate progress notifications, we must notify all goroutines
- // waiting for the diagnose pass following a didChangeWatchedFiles
- // notification. This is necessary for regtest assertions.
- var dones []chan struct{}
- for _, pending := range s.pendingOnDiskChanges {
- allChanges = append(allChanges, pending.changes...)
- dones = append(dones, pending.diagnoseDone)
- }
-
- allDone := make(chan struct{})
- if err := s.processModifications(ctx, allChanges, onDisk, allDone); err != nil {
- event.Error(ctx, "processing delayed file changes", err)
- }
- s.pendingOnDiskChanges = nil
- s.fileChangeMu.Unlock()
- <-allDone
- for _, done := range dones {
- close(done)
- }
- }()
- return nil
+ return s.processModifications(ctx, modifications, onDisk, diagnoseDone)
 }
 
 // processModifications update server state to reflect file changes, and