| // Copyright 2020 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // The progress package defines utilities for reporting the progress |
| // of long-running operations using features of the LSP client |
| // interface such as Progress and ShowMessage. |
| package progress |
| |
| import ( |
| "context" |
| "fmt" |
| "io" |
| "math/rand" |
| "strconv" |
| "strings" |
| "sync" |
| |
| "golang.org/x/tools/gopls/internal/protocol" |
| "golang.org/x/tools/internal/event" |
| "golang.org/x/tools/internal/event/tag" |
| "golang.org/x/tools/internal/xcontext" |
| ) |
| |
| // NewTracker returns a new Tracker that reports progress to the |
| // specified client. |
| func NewTracker(client protocol.Client) *Tracker { |
| return &Tracker{ |
| client: client, |
| inProgress: make(map[protocol.ProgressToken]*WorkDone), |
| } |
| } |
| |
| // A Tracker reports the progress of a long-running operation to an LSP client. |
| type Tracker struct { |
| client protocol.Client |
| supportsWorkDoneProgress bool |
| |
| mu sync.Mutex |
| inProgress map[protocol.ProgressToken]*WorkDone |
| } |
| |
| // SetSupportsWorkDoneProgress sets whether the client supports "work done" |
| // progress reporting. It must be set before using the tracker. |
| // |
| // TODO(rfindley): fix this broken initialization pattern. |
| // Also: do we actually need the fall-back progress behavior using ShowMessage? |
| // Surely ShowMessage notifications are too noisy to be worthwhile. |
| func (t *Tracker) SetSupportsWorkDoneProgress(b bool) { |
| t.supportsWorkDoneProgress = b |
| } |
| |
| // SupportsWorkDoneProgress reports whether the tracker supports work done |
| // progress reporting. |
| func (t *Tracker) SupportsWorkDoneProgress() bool { |
| return t.supportsWorkDoneProgress |
| } |
| |
| // Start notifies the client of work being done on the server. It uses either |
| // ShowMessage RPCs or $/progress messages, depending on the capabilities of |
| // the client. The returned WorkDone handle may be used to report incremental |
| // progress, and to report work completion. In particular, it is an error to |
| // call start and not call end(...) on the returned WorkDone handle. |
| // |
| // If token is empty, a token will be randomly generated. |
| // |
| // The progress item is considered cancellable if the given cancel func is |
| // non-nil. In this case, cancel is called when the work done |
| // |
| // Example: |
| // |
| // func Generate(ctx) (err error) { |
| // ctx, cancel := context.WithCancel(ctx) |
| // defer cancel() |
| // work := s.progress.start(ctx, "generate", "running go generate", cancel) |
| // defer func() { |
| // if err != nil { |
| // work.end(ctx, fmt.Sprintf("generate failed: %v", err)) |
| // } else { |
| // work.end(ctx, "done") |
| // } |
| // }() |
| // // Do the work... |
| // } |
| func (t *Tracker) Start(ctx context.Context, title, message string, token protocol.ProgressToken, cancel func()) *WorkDone { |
| ctx = xcontext.Detach(ctx) // progress messages should not be cancelled |
| wd := &WorkDone{ |
| client: t.client, |
| token: token, |
| cancel: cancel, |
| } |
| if !t.supportsWorkDoneProgress { |
| // Previous iterations of this fallback attempted to retain cancellation |
| // support by using ShowMessageCommand with a 'Cancel' button, but this is |
| // not ideal as the 'Cancel' dialog stays open even after the command |
| // completes. |
| // |
| // Just show a simple message. Clients can implement workDone progress |
| // reporting to get cancellation support. |
| if err := wd.client.ShowMessage(ctx, &protocol.ShowMessageParams{ |
| Type: protocol.Log, |
| Message: message, |
| }); err != nil { |
| event.Error(ctx, "showing start message for "+title, err) |
| } |
| return wd |
| } |
| if wd.token == nil { |
| token = strconv.FormatInt(rand.Int63(), 10) |
| err := wd.client.WorkDoneProgressCreate(ctx, &protocol.WorkDoneProgressCreateParams{ |
| Token: token, |
| }) |
| if err != nil { |
| wd.err = err |
| event.Error(ctx, "starting work for "+title, err) |
| return wd |
| } |
| wd.token = token |
| } |
| // At this point we have a token that the client knows about. Store the token |
| // before starting work. |
| t.mu.Lock() |
| t.inProgress[wd.token] = wd |
| t.mu.Unlock() |
| wd.cleanup = func() { |
| t.mu.Lock() |
| delete(t.inProgress, token) |
| t.mu.Unlock() |
| } |
| err := wd.client.Progress(ctx, &protocol.ProgressParams{ |
| Token: wd.token, |
| Value: &protocol.WorkDoneProgressBegin{ |
| Kind: "begin", |
| Cancellable: wd.cancel != nil, |
| Message: message, |
| Title: title, |
| }, |
| }) |
| if err != nil { |
| event.Error(ctx, "progress begin", err) |
| } |
| return wd |
| } |
| |
| func (t *Tracker) Cancel(token protocol.ProgressToken) error { |
| t.mu.Lock() |
| defer t.mu.Unlock() |
| wd, ok := t.inProgress[token] |
| if !ok { |
| return fmt.Errorf("token %q not found in progress", token) |
| } |
| if wd.cancel == nil { |
| return fmt.Errorf("work %q is not cancellable", token) |
| } |
| wd.doCancel() |
| return nil |
| } |
| |
| // WorkDone represents a unit of work that is reported to the client via the |
| // progress API. |
| type WorkDone struct { |
| client protocol.Client |
| // If token is nil, this workDone object uses the ShowMessage API, rather |
| // than $/progress. |
| token protocol.ProgressToken |
| // err is set if progress reporting is broken for some reason (for example, |
| // if there was an initial error creating a token). |
| err error |
| |
| cancelMu sync.Mutex |
| cancelled bool |
| cancel func() |
| |
| cleanup func() |
| } |
| |
| func (wd *WorkDone) Token() protocol.ProgressToken { |
| return wd.token |
| } |
| |
| func (wd *WorkDone) doCancel() { |
| wd.cancelMu.Lock() |
| defer wd.cancelMu.Unlock() |
| if !wd.cancelled { |
| wd.cancel() |
| } |
| } |
| |
| // Report reports an update on WorkDone report back to the client. |
| func (wd *WorkDone) Report(ctx context.Context, message string, percentage float64) { |
| ctx = xcontext.Detach(ctx) // progress messages should not be cancelled |
| if wd == nil { |
| return |
| } |
| wd.cancelMu.Lock() |
| cancelled := wd.cancelled |
| wd.cancelMu.Unlock() |
| if cancelled { |
| return |
| } |
| if wd.err != nil || wd.token == nil { |
| // Not using the workDone API, so we do nothing. It would be far too spammy |
| // to send incremental messages. |
| return |
| } |
| message = strings.TrimSuffix(message, "\n") |
| err := wd.client.Progress(ctx, &protocol.ProgressParams{ |
| Token: wd.token, |
| Value: &protocol.WorkDoneProgressReport{ |
| Kind: "report", |
| // Note that in the LSP spec, the value of Cancellable may be changed to |
| // control whether the cancel button in the UI is enabled. Since we don't |
| // yet use this feature, the value is kept constant here. |
| Cancellable: wd.cancel != nil, |
| Message: message, |
| Percentage: uint32(percentage), |
| }, |
| }) |
| if err != nil { |
| event.Error(ctx, "reporting progress", err) |
| } |
| } |
| |
| // End reports a workdone completion back to the client. |
| func (wd *WorkDone) End(ctx context.Context, message string) { |
| ctx = xcontext.Detach(ctx) // progress messages should not be cancelled |
| if wd == nil { |
| return |
| } |
| var err error |
| switch { |
| case wd.err != nil: |
| // There is a prior error. |
| case wd.token == nil: |
| // We're falling back to message-based reporting. |
| err = wd.client.ShowMessage(ctx, &protocol.ShowMessageParams{ |
| Type: protocol.Info, |
| Message: message, |
| }) |
| default: |
| err = wd.client.Progress(ctx, &protocol.ProgressParams{ |
| Token: wd.token, |
| Value: &protocol.WorkDoneProgressEnd{ |
| Kind: "end", |
| Message: message, |
| }, |
| }) |
| } |
| if err != nil { |
| event.Error(ctx, "ending work", err) |
| } |
| if wd.cleanup != nil { |
| wd.cleanup() |
| } |
| } |
| |
| // NewEventWriter returns an [io.Writer] that calls the context's |
| // event printer for each data payload, wrapping it with the |
| // operation=generate tag to distinguish its logs from others. |
| func NewEventWriter(ctx context.Context, operation string) io.Writer { |
| return &eventWriter{ctx: ctx, operation: operation} |
| } |
| |
| type eventWriter struct { |
| ctx context.Context |
| operation string |
| } |
| |
| func (ew *eventWriter) Write(p []byte) (n int, err error) { |
| event.Log(ew.ctx, string(p), tag.Operation.Of(ew.operation)) |
| return len(p), nil |
| } |
| |
| // NewWorkDoneWriter wraps a WorkDone handle to provide a Writer interface, |
| // so that workDone reporting can more easily be hooked into commands. |
| func NewWorkDoneWriter(ctx context.Context, wd *WorkDone) io.Writer { |
| return &workDoneWriter{ctx: ctx, wd: wd} |
| } |
| |
| // workDoneWriter wraps a workDone handle to provide a Writer interface, |
| // so that workDone reporting can more easily be hooked into commands. |
| type workDoneWriter struct { |
| // In order to implement the io.Writer interface, we must close over ctx. |
| ctx context.Context |
| wd *WorkDone |
| } |
| |
| func (wdw *workDoneWriter) Write(p []byte) (n int, err error) { |
| wdw.wd.Report(wdw.ctx, string(p), 0) |
| // Don't fail just because of a failure to report progress. |
| return len(p), nil |
| } |