internal/lsp/progress.go - tools - Git at Google

 // 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.

 package lsp

 import (
 	"context"
 	"math/rand"
 	"strconv"
 	"strings"
 	"sync"

 	"golang.org/x/tools/internal/event"
 	"golang.org/x/tools/internal/lsp/debug/tag"
 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/xcontext"
 	errors "golang.org/x/xerrors"
 )

 type progressTracker struct {
 	client                   protocol.Client
 	supportsWorkDoneProgress bool

 	mu         sync.Mutex
 	inProgress map[protocol.ProgressToken]*workDone
 }

 func newProgressTracker(client protocol.Client) *progressTracker {
 	return &progressTracker{
 		client:     client,
 		inProgress: make(map[protocol.ProgressToken]*workDone),
 	}
 }

 // 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 *progressTracker) start(ctx context.Context, title, message string, token protocol.ProgressToken, cancel func()) *workDone {
 	wd := &workDone{
 		ctx:    xcontext.Detach(ctx),
 		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(wd.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, "generate progress begin", err)
 	}
 	return wd
 }

 func (t *progressTracker) cancel(ctx context.Context, token protocol.ProgressToken) error {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	wd, ok := t.inProgress[token]
 	if !ok {
 		return errors.Errorf("token %q not found in progress", token)
 	}
 	if wd.cancel == nil {
 		return errors.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 {
 	// ctx is detached, for sending $/progress updates.
 	ctx    context.Context
 	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) 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(message string, percentage float64) {
 	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(wd.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(wd.ctx, "reporting progress", err)
 	}
 }

 // end reports a workdone completion back to the client.
 func (wd *workDone) end(message string) {
 	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(wd.ctx, &protocol.ShowMessageParams{
 			Type:    protocol.Info,
 			Message: message,
 		})
 	default:
 		err = wd.client.Progress(wd.ctx, &protocol.ProgressParams{
 			Token: wd.token,
 			Value: &protocol.WorkDoneProgressEnd{
 				Kind:    "end",
 				Message: message,
 			},
 		})
 	}
 	if err != nil {
 		event.Error(wd.ctx, "ending work", err)
 	}
 	if wd.cleanup != nil {
 		wd.cleanup()
 	}
 }

 // eventWriter writes every incoming []byte to
 // event.Print with the operation=generate tag
 // to distinguish its logs from others.
 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
 }

 // workDoneWriter wraps a workDone handle to provide a Writer interface,
 // so that workDone reporting can more easily be hooked into commands.
 type workDoneWriter struct {
 	wd *workDone
 }

 func (wdw workDoneWriter) Write(p []byte) (n int, err error) {
 	wdw.wd.report(string(p), 0)
 	// Don't fail just because of a failure to report progress.
 	return len(p), nil
 }
	// 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.

	package lsp

	import (
	"context"
	"math/rand"
	"strconv"
	"strings"
	"sync"

	"golang.org/x/tools/internal/event"
	"golang.org/x/tools/internal/lsp/debug/tag"
	"golang.org/x/tools/internal/lsp/protocol"
	"golang.org/x/tools/internal/xcontext"
	errors "golang.org/x/xerrors"
	)

	type progressTracker struct {
	client protocol.Client
	supportsWorkDoneProgress bool

	mu sync.Mutex
	inProgress map[protocol.ProgressToken]*workDone
	}

	func newProgressTracker(client protocol.Client) *progressTracker {
	return &progressTracker{
	client: client,
	inProgress: make(map[protocol.ProgressToken]*workDone),
	}
	}

	// 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 progressTracker) start(ctx context.Context, title, message string, token protocol.ProgressToken, cancel func()) workDone {
	wd := &workDone{
	ctx: xcontext.Detach(ctx),
	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(wd.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, "generate progress begin", err)
	}
	return wd
	}

	func (t *progressTracker) cancel(ctx context.Context, token protocol.ProgressToken) error {
	t.mu.Lock()
	defer t.mu.Unlock()
	wd, ok := t.inProgress[token]
	if !ok {
	return errors.Errorf("token %q not found in progress", token)
	}
	if wd.cancel == nil {
	return errors.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 {
	// ctx is detached, for sending $/progress updates.
	ctx context.Context
	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) 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(message string, percentage float64) {
	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(wd.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(wd.ctx, "reporting progress", err)
	}
	}

	// end reports a workdone completion back to the client.
	func (wd *workDone) end(message string) {
	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(wd.ctx, &protocol.ShowMessageParams{
	Type: protocol.Info,
	Message: message,
	})
	default:
	err = wd.client.Progress(wd.ctx, &protocol.ProgressParams{
	Token: wd.token,
	Value: &protocol.WorkDoneProgressEnd{
	Kind: "end",
	Message: message,
	},
	})
	}
	if err != nil {
	event.Error(wd.ctx, "ending work", err)
	}
	if wd.cleanup != nil {
	wd.cleanup()
	}
	}

	// eventWriter writes every incoming []byte to
	// event.Print with the operation=generate tag
	// to distinguish its logs from others.
	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
	}

	// workDoneWriter wraps a workDone handle to provide a Writer interface,
	// so that workDone reporting can more easily be hooked into commands.
	type workDoneWriter struct {
	wd *workDone
	}

	func (wdw workDoneWriter) Write(p []byte) (n int, err error) {
	wdw.wd.report(string(p), 0)
	// Don't fail just because of a failure to report progress.
	return len(p), nil
	}