internal/lsp/fake/workdir.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 fake

 import (
 	"bytes"
 	"context"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
 	"sync"
 	"time"

 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/span"
 	errors "golang.org/x/xerrors"
 )

 // FileEvent wraps the protocol.FileEvent so that it can be associated with a
 // workdir-relative path.
 type FileEvent struct {
 	Path, Content string
 	ProtocolEvent protocol.FileEvent
 }

 // RelativeTo is a helper for operations relative to a given directory.
 type RelativeTo string

 // AbsPath returns an absolute filesystem path for the workdir-relative path.
 func (r RelativeTo) AbsPath(path string) string {
 	fp := filepath.FromSlash(path)
 	if filepath.IsAbs(fp) {
 		return fp
 	}
 	return filepath.Join(string(r), filepath.FromSlash(path))
 }

 // RelPath returns a '/'-encoded path relative to the working directory (or an
 // absolute path if the file is outside of workdir)
 func (r RelativeTo) RelPath(fp string) string {
 	root := string(r)
 	if rel, err := filepath.Rel(root, fp); err == nil && !strings.HasPrefix(rel, "..") {
 		return filepath.ToSlash(rel)
 	}
 	return filepath.ToSlash(fp)
 }

 func writeTxtar(txt string, rel RelativeTo) error {
 	files := unpackTxt(txt)
 	for name, data := range files {
 		if err := WriteFileData(name, data, rel); err != nil {
 			return errors.Errorf("writing to workdir: %w", err)
 		}
 	}
 	return nil
 }

 // WriteFileData writes content to the relative path, replacing the special
 // token $SANDBOX_WORKDIR with the relative root given by rel.
 func WriteFileData(path string, content []byte, rel RelativeTo) error {
 	content = bytes.ReplaceAll(content, []byte("$SANDBOX_WORKDIR"), []byte(rel))
 	fp := rel.AbsPath(path)
 	if err := os.MkdirAll(filepath.Dir(fp), 0755); err != nil {
 		return errors.Errorf("creating nested directory: %w", err)
 	}
 	if err := ioutil.WriteFile(fp, []byte(content), 0644); err != nil {
 		return errors.Errorf("writing %q: %w", path, err)
 	}
 	return nil
 }

 // Workdir is a temporary working directory for tests. It exposes file
 // operations in terms of relative paths, and fakes file watching by triggering
 // events on file operations.
 type Workdir struct {
 	RelativeTo

 	watcherMu sync.Mutex
 	watchers  []func(context.Context, []FileEvent)

 	fileMu sync.Mutex
 	files  map[string]time.Time
 }

 // NewWorkdir writes the txtar-encoded file data in txt to dir, and returns a
 // Workir for operating on these files using
 func NewWorkdir(dir string) *Workdir {
 	return &Workdir{RelativeTo: RelativeTo(dir)}
 }

 func (w *Workdir) writeInitialFiles(txt string) error {
 	writeTxtar(txt, w.RelativeTo)
 	// Poll to capture the current file state.
 	if _, err := w.pollFiles(); err != nil {
 		return errors.Errorf("polling files: %w", err)
 	}
 	return nil
 }

 // RootURI returns the root URI for this working directory of this scratch
 // environment.
 func (w *Workdir) RootURI() protocol.DocumentURI {
 	return toURI(string(w.RelativeTo))
 }

 // AddWatcher registers the given func to be called on any file change.
 func (w *Workdir) AddWatcher(watcher func(context.Context, []FileEvent)) {
 	w.watcherMu.Lock()
 	w.watchers = append(w.watchers, watcher)
 	w.watcherMu.Unlock()
 }

 // URI returns the URI to a the workdir-relative path.
 func (w *Workdir) URI(path string) protocol.DocumentURI {
 	return toURI(w.AbsPath(path))
 }

 // URIToPath converts a uri to a workdir-relative path (or an absolute path,
 // if the uri is outside of the workdir).
 func (w *Workdir) URIToPath(uri protocol.DocumentURI) string {
 	fp := uri.SpanURI().Filename()
 	return w.RelPath(fp)
 }

 func toURI(fp string) protocol.DocumentURI {
 	return protocol.DocumentURI(span.URIFromPath(fp))
 }

 // ReadFile reads a text file specified by a workdir-relative path.
 func (w *Workdir) ReadFile(path string) (string, error) {
 	b, err := ioutil.ReadFile(w.AbsPath(path))
 	if err != nil {
 		return "", err
 	}
 	return string(b), nil
 }

 func (w *Workdir) RegexpRange(path, re string) (Pos, Pos, error) {
 	content, err := w.ReadFile(path)
 	if err != nil {
 		return Pos{}, Pos{}, err
 	}
 	return regexpRange(content, re)
 }

 // RegexpSearch searches the file corresponding to path for the first position
 // matching re.
 func (w *Workdir) RegexpSearch(path string, re string) (Pos, error) {
 	content, err := w.ReadFile(path)
 	if err != nil {
 		return Pos{}, err
 	}
 	start, _, err := regexpRange(content, re)
 	return start, err
 }

 // ChangeFilesOnDisk executes the given on-disk file changes in a batch,
 // simulating the action of changing branches outside of an editor.
 func (w *Workdir) ChangeFilesOnDisk(ctx context.Context, events []FileEvent) error {
 	for _, e := range events {
 		switch e.ProtocolEvent.Type {
 		case protocol.Deleted:
 			fp := w.AbsPath(e.Path)
 			if err := os.Remove(fp); err != nil {
 				return errors.Errorf("removing %q: %w", e.Path, err)
 			}
 		case protocol.Changed, protocol.Created:
 			if _, err := w.writeFile(ctx, e.Path, e.Content); err != nil {
 				return err
 			}
 		}
 	}
 	w.sendEvents(ctx, events)
 	return nil
 }

 // RemoveFile removes a workdir-relative file path.
 func (w *Workdir) RemoveFile(ctx context.Context, path string) error {
 	fp := w.AbsPath(path)
 	if err := os.RemoveAll(fp); err != nil {
 		return errors.Errorf("removing %q: %w", path, err)
 	}
 	evts := []FileEvent{{
 		Path: path,
 		ProtocolEvent: protocol.FileEvent{
 			URI:  w.URI(path),
 			Type: protocol.Deleted,
 		},
 	}}
 	w.sendEvents(ctx, evts)
 	return nil
 }

 func (w *Workdir) sendEvents(ctx context.Context, evts []FileEvent) {
 	if len(evts) == 0 {
 		return
 	}
 	w.watcherMu.Lock()
 	watchers := make([]func(context.Context, []FileEvent), len(w.watchers))
 	copy(watchers, w.watchers)
 	w.watcherMu.Unlock()
 	for _, w := range watchers {
 		go w(ctx, evts)
 	}
 }

 // WriteFiles writes the text file content to workdir-relative paths.
 // It batches notifications rather than sending them consecutively.
 func (w *Workdir) WriteFiles(ctx context.Context, files map[string]string) error {
 	var evts []FileEvent
 	for filename, content := range files {
 		evt, err := w.writeFile(ctx, filename, content)
 		if err != nil {
 			return err
 		}
 		evts = append(evts, evt)
 	}
 	w.sendEvents(ctx, evts)
 	return nil
 }

 // WriteFile writes text file content to a workdir-relative path.
 func (w *Workdir) WriteFile(ctx context.Context, path, content string) error {
 	evt, err := w.writeFile(ctx, path, content)
 	if err != nil {
 		return err
 	}
 	w.sendEvents(ctx, []FileEvent{evt})
 	return nil
 }

 func (w *Workdir) writeFile(ctx context.Context, path, content string) (FileEvent, error) {
 	fp := w.AbsPath(path)
 	_, err := os.Stat(fp)
 	if err != nil && !os.IsNotExist(err) {
 		return FileEvent{}, errors.Errorf("checking if %q exists: %w", path, err)
 	}
 	var changeType protocol.FileChangeType
 	if os.IsNotExist(err) {
 		changeType = protocol.Created
 	} else {
 		changeType = protocol.Changed
 	}
 	if err := WriteFileData(path, []byte(content), w.RelativeTo); err != nil {
 		return FileEvent{}, err
 	}
 	return FileEvent{
 		Path: path,
 		ProtocolEvent: protocol.FileEvent{
 			URI:  w.URI(path),
 			Type: changeType,
 		},
 	}, nil
 }

 // ListFiles lists files in the given directory, returning a map of relative
 // path to modification time.
 func (w *Workdir) ListFiles(dir string) (map[string]time.Time, error) {
 	files := make(map[string]time.Time)
 	absDir := w.AbsPath(dir)
 	if err := filepath.Walk(absDir, func(fp string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
 		if info.IsDir() {
 			return nil
 		}
 		path := w.RelPath(fp)
 		files[path] = info.ModTime()
 		return nil
 	}); err != nil {
 		return nil, err
 	}
 	return files, nil
 }

 // CheckForFileChanges walks the working directory and checks for any files
 // that have changed since the last poll.
 func (w *Workdir) CheckForFileChanges(ctx context.Context) error {
 	evts, err := w.pollFiles()
 	if err != nil {
 		return err
 	}
 	w.sendEvents(ctx, evts)
 	return nil
 }

 // pollFiles updates w.files and calculates FileEvents corresponding to file
 // state changes since the last poll. It does not call sendEvents.
 func (w *Workdir) pollFiles() ([]FileEvent, error) {
 	w.fileMu.Lock()
 	defer w.fileMu.Unlock()

 	files, err := w.ListFiles(".")
 	if err != nil {
 		return nil, err
 	}
 	var evts []FileEvent
 	// Check which files have been added or modified.
 	for path, mtime := range files {
 		oldmtime, ok := w.files[path]
 		delete(w.files, path)
 		var typ protocol.FileChangeType
 		switch {
 		case !ok:
 			typ = protocol.Created
 		case oldmtime != mtime:
 			typ = protocol.Changed
 		default:
 			continue
 		}
 		evts = append(evts, FileEvent{
 			Path: path,
 			ProtocolEvent: protocol.FileEvent{
 				URI:  w.URI(path),
 				Type: typ,
 			},
 		})
 	}
 	// Any remaining files must have been deleted.
 	for path := range w.files {
 		evts = append(evts, FileEvent{
 			Path: path,
 			ProtocolEvent: protocol.FileEvent{
 				URI:  w.URI(path),
 				Type: protocol.Deleted,
 			},
 		})
 	}
 	w.files = files
 	return evts, 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 fake

	import (
	"bytes"
	"context"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"time"

	"golang.org/x/tools/internal/lsp/protocol"
	"golang.org/x/tools/internal/span"
	errors "golang.org/x/xerrors"
	)

	// FileEvent wraps the protocol.FileEvent so that it can be associated with a
	// workdir-relative path.
	type FileEvent struct {
	Path, Content string
	ProtocolEvent protocol.FileEvent
	}

	// RelativeTo is a helper for operations relative to a given directory.
	type RelativeTo string

	// AbsPath returns an absolute filesystem path for the workdir-relative path.
	func (r RelativeTo) AbsPath(path string) string {
	fp := filepath.FromSlash(path)
	if filepath.IsAbs(fp) {
	return fp
	}
	return filepath.Join(string(r), filepath.FromSlash(path))
	}

	// RelPath returns a '/'-encoded path relative to the working directory (or an
	// absolute path if the file is outside of workdir)
	func (r RelativeTo) RelPath(fp string) string {
	root := string(r)
	if rel, err := filepath.Rel(root, fp); err == nil && !strings.HasPrefix(rel, "..") {
	return filepath.ToSlash(rel)
	}
	return filepath.ToSlash(fp)
	}

	func writeTxtar(txt string, rel RelativeTo) error {
	files := unpackTxt(txt)
	for name, data := range files {
	if err := WriteFileData(name, data, rel); err != nil {
	return errors.Errorf("writing to workdir: %w", err)
	}
	}
	return nil
	}

	// WriteFileData writes content to the relative path, replacing the special
	// token $SANDBOX_WORKDIR with the relative root given by rel.
	func WriteFileData(path string, content []byte, rel RelativeTo) error {
	content = bytes.ReplaceAll(content, []byte("$SANDBOX_WORKDIR"), []byte(rel))
	fp := rel.AbsPath(path)
	if err := os.MkdirAll(filepath.Dir(fp), 0755); err != nil {
	return errors.Errorf("creating nested directory: %w", err)
	}
	if err := ioutil.WriteFile(fp, []byte(content), 0644); err != nil {
	return errors.Errorf("writing %q: %w", path, err)
	}
	return nil
	}

	// Workdir is a temporary working directory for tests. It exposes file
	// operations in terms of relative paths, and fakes file watching by triggering
	// events on file operations.
	type Workdir struct {
	RelativeTo

	watcherMu sync.Mutex
	watchers []func(context.Context, []FileEvent)

	fileMu sync.Mutex
	files map[string]time.Time
	}

	// NewWorkdir writes the txtar-encoded file data in txt to dir, and returns a
	// Workir for operating on these files using
	func NewWorkdir(dir string) *Workdir {
	return &Workdir{RelativeTo: RelativeTo(dir)}
	}

	func (w *Workdir) writeInitialFiles(txt string) error {
	writeTxtar(txt, w.RelativeTo)
	// Poll to capture the current file state.
	if _, err := w.pollFiles(); err != nil {
	return errors.Errorf("polling files: %w", err)
	}
	return nil
	}

	// RootURI returns the root URI for this working directory of this scratch
	// environment.
	func (w *Workdir) RootURI() protocol.DocumentURI {
	return toURI(string(w.RelativeTo))
	}

	// AddWatcher registers the given func to be called on any file change.
	func (w *Workdir) AddWatcher(watcher func(context.Context, []FileEvent)) {
	w.watcherMu.Lock()
	w.watchers = append(w.watchers, watcher)
	w.watcherMu.Unlock()
	}

	// URI returns the URI to a the workdir-relative path.
	func (w *Workdir) URI(path string) protocol.DocumentURI {
	return toURI(w.AbsPath(path))
	}

	// URIToPath converts a uri to a workdir-relative path (or an absolute path,
	// if the uri is outside of the workdir).
	func (w *Workdir) URIToPath(uri protocol.DocumentURI) string {
	fp := uri.SpanURI().Filename()
	return w.RelPath(fp)
	}

	func toURI(fp string) protocol.DocumentURI {
	return protocol.DocumentURI(span.URIFromPath(fp))
	}

	// ReadFile reads a text file specified by a workdir-relative path.
	func (w *Workdir) ReadFile(path string) (string, error) {
	b, err := ioutil.ReadFile(w.AbsPath(path))
	if err != nil {
	return "", err
	}
	return string(b), nil
	}

	func (w *Workdir) RegexpRange(path, re string) (Pos, Pos, error) {
	content, err := w.ReadFile(path)
	if err != nil {
	return Pos{}, Pos{}, err
	}
	return regexpRange(content, re)
	}

	// RegexpSearch searches the file corresponding to path for the first position
	// matching re.
	func (w *Workdir) RegexpSearch(path string, re string) (Pos, error) {
	content, err := w.ReadFile(path)
	if err != nil {
	return Pos{}, err
	}
	start, _, err := regexpRange(content, re)
	return start, err
	}

	// ChangeFilesOnDisk executes the given on-disk file changes in a batch,
	// simulating the action of changing branches outside of an editor.
	func (w *Workdir) ChangeFilesOnDisk(ctx context.Context, events []FileEvent) error {
	for _, e := range events {
	switch e.ProtocolEvent.Type {
	case protocol.Deleted:
	fp := w.AbsPath(e.Path)
	if err := os.Remove(fp); err != nil {
	return errors.Errorf("removing %q: %w", e.Path, err)
	}
	case protocol.Changed, protocol.Created:
	if _, err := w.writeFile(ctx, e.Path, e.Content); err != nil {
	return err
	}
	}
	}
	w.sendEvents(ctx, events)
	return nil
	}

	// RemoveFile removes a workdir-relative file path.
	func (w *Workdir) RemoveFile(ctx context.Context, path string) error {
	fp := w.AbsPath(path)
	if err := os.RemoveAll(fp); err != nil {
	return errors.Errorf("removing %q: %w", path, err)
	}
	evts := []FileEvent{{
	Path: path,
	ProtocolEvent: protocol.FileEvent{
	URI: w.URI(path),
	Type: protocol.Deleted,
	},
	}}
	w.sendEvents(ctx, evts)
	return nil
	}

	func (w *Workdir) sendEvents(ctx context.Context, evts []FileEvent) {
	if len(evts) == 0 {
	return
	}
	w.watcherMu.Lock()
	watchers := make([]func(context.Context, []FileEvent), len(w.watchers))
	copy(watchers, w.watchers)
	w.watcherMu.Unlock()
	for _, w := range watchers {
	go w(ctx, evts)
	}
	}

	// WriteFiles writes the text file content to workdir-relative paths.
	// It batches notifications rather than sending them consecutively.
	func (w *Workdir) WriteFiles(ctx context.Context, files map[string]string) error {
	var evts []FileEvent
	for filename, content := range files {
	evt, err := w.writeFile(ctx, filename, content)
	if err != nil {
	return err
	}
	evts = append(evts, evt)
	}
	w.sendEvents(ctx, evts)
	return nil
	}

	// WriteFile writes text file content to a workdir-relative path.
	func (w *Workdir) WriteFile(ctx context.Context, path, content string) error {
	evt, err := w.writeFile(ctx, path, content)
	if err != nil {
	return err
	}
	w.sendEvents(ctx, []FileEvent{evt})
	return nil
	}

	func (w *Workdir) writeFile(ctx context.Context, path, content string) (FileEvent, error) {
	fp := w.AbsPath(path)
	_, err := os.Stat(fp)
	if err != nil && !os.IsNotExist(err) {
	return FileEvent{}, errors.Errorf("checking if %q exists: %w", path, err)
	}
	var changeType protocol.FileChangeType
	if os.IsNotExist(err) {
	changeType = protocol.Created
	} else {
	changeType = protocol.Changed
	}
	if err := WriteFileData(path, []byte(content), w.RelativeTo); err != nil {
	return FileEvent{}, err
	}
	return FileEvent{
	Path: path,
	ProtocolEvent: protocol.FileEvent{
	URI: w.URI(path),
	Type: changeType,
	},
	}, nil
	}

	// ListFiles lists files in the given directory, returning a map of relative
	// path to modification time.
	func (w *Workdir) ListFiles(dir string) (map[string]time.Time, error) {
	files := make(map[string]time.Time)
	absDir := w.AbsPath(dir)
	if err := filepath.Walk(absDir, func(fp string, info os.FileInfo, err error) error {
	if err != nil {
	return err
	}
	if info.IsDir() {
	return nil
	}
	path := w.RelPath(fp)
	files[path] = info.ModTime()
	return nil
	}); err != nil {
	return nil, err
	}
	return files, nil
	}

	// CheckForFileChanges walks the working directory and checks for any files
	// that have changed since the last poll.
	func (w *Workdir) CheckForFileChanges(ctx context.Context) error {
	evts, err := w.pollFiles()
	if err != nil {
	return err
	}
	w.sendEvents(ctx, evts)
	return nil
	}

	// pollFiles updates w.files and calculates FileEvents corresponding to file
	// state changes since the last poll. It does not call sendEvents.
	func (w *Workdir) pollFiles() ([]FileEvent, error) {
	w.fileMu.Lock()
	defer w.fileMu.Unlock()

	files, err := w.ListFiles(".")
	if err != nil {
	return nil, err
	}
	var evts []FileEvent
	// Check which files have been added or modified.
	for path, mtime := range files {
	oldmtime, ok := w.files[path]
	delete(w.files, path)
	var typ protocol.FileChangeType
	switch {
	case !ok:
	typ = protocol.Created
	case oldmtime != mtime:
	typ = protocol.Changed
	default:
	continue
	}
	evts = append(evts, FileEvent{
	Path: path,
	ProtocolEvent: protocol.FileEvent{
	URI: w.URI(path),
	Type: typ,
	},
	})
	}
	// Any remaining files must have been deleted.
	for path := range w.files {
	evts = append(evts, FileEvent{
	Path: path,
	ProtocolEvent: protocol.FileEvent{
	URI: w.URI(path),
	Type: protocol.Deleted,
	},
	})
	}
	w.files = files
	return evts, nil
	}