blob: 514834b077c77505f50b4d892c300c1e133bfa5f [file] [log] [blame]
// Copyright 2019 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 (
"bytes"
"context"
"errors"
"fmt"
"path/filepath"
"time"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/jsonrpc2"
"golang.org/x/tools/internal/lsp/protocol"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/span"
"golang.org/x/tools/internal/xcontext"
)
// ModificationSource identifies the originating cause of a file modification.
type ModificationSource int
const (
// FromDidOpen is a file modification caused by opening a file.
FromDidOpen = ModificationSource(iota)
// FromDidChange is a file modification caused by changing a file.
FromDidChange
// FromDidChangeWatchedFiles is a file modification caused by a change to a
// watched file.
FromDidChangeWatchedFiles
// FromDidSave is a file modification caused by a file save.
FromDidSave
// FromDidClose is a file modification caused by closing a file.
FromDidClose
// FromRegenerateCgo refers to file modifications caused by regenerating
// the cgo sources for the workspace.
FromRegenerateCgo
// FromInitialWorkspaceLoad refers to the loading of all packages in the
// workspace when the view is first created.
FromInitialWorkspaceLoad
)
func (m ModificationSource) String() string {
switch m {
case FromDidOpen:
return "opened files"
case FromDidChange:
return "changed files"
case FromDidChangeWatchedFiles:
return "files changed on disk"
case FromDidSave:
return "saved files"
case FromDidClose:
return "close files"
case FromRegenerateCgo:
return "regenerate cgo"
case FromInitialWorkspaceLoad:
return "initial workspace load"
default:
return "unknown file modification"
}
}
func (s *Server) didOpen(ctx context.Context, params *protocol.DidOpenTextDocumentParams) error {
uri := params.TextDocument.URI.SpanURI()
if !uri.IsFile() {
return nil
}
// There may not be any matching view in the current session. If that's
// the case, try creating a new view based on the opened file path.
//
// TODO(rstambler): This seems like it would continuously add new
// views, but it won't because ViewOf only returns an error when there
// are no views in the session. I don't know if that logic should go
// here, or if we can continue to rely on that implementation detail.
if _, err := s.session.ViewOf(uri); err != nil {
dir := filepath.Dir(uri.Filename())
if err := s.addFolders(ctx, []protocol.WorkspaceFolder{{
URI: string(protocol.URIFromPath(dir)),
Name: filepath.Base(dir),
}}); err != nil {
return err
}
}
return s.didModifyFiles(ctx, []source.FileModification{{
URI: uri,
Action: source.Open,
Version: params.TextDocument.Version,
Text: []byte(params.TextDocument.Text),
LanguageID: params.TextDocument.LanguageID,
}}, FromDidOpen)
}
func (s *Server) didChange(ctx context.Context, params *protocol.DidChangeTextDocumentParams) error {
uri := params.TextDocument.URI.SpanURI()
if !uri.IsFile() {
return nil
}
text, err := s.changedText(ctx, uri, params.ContentChanges)
if err != nil {
return err
}
c := source.FileModification{
URI: uri,
Action: source.Change,
Version: params.TextDocument.Version,
Text: text,
}
if err := s.didModifyFiles(ctx, []source.FileModification{c}, FromDidChange); err != nil {
return err
}
return s.warnAboutModifyingGeneratedFiles(ctx, uri)
}
// warnAboutModifyingGeneratedFiles shows a warning if a user tries to edit a
// generated file for the first time.
func (s *Server) warnAboutModifyingGeneratedFiles(ctx context.Context, uri span.URI) error {
s.changedFilesMu.Lock()
_, ok := s.changedFiles[uri]
if !ok {
s.changedFiles[uri] = struct{}{}
}
s.changedFilesMu.Unlock()
// This file has already been edited before.
if ok {
return nil
}
// Ideally, we should be able to specify that a generated file should
// be opened as read-only. Tell the user that they should not be
// editing a generated file.
view, err := s.session.ViewOf(uri)
if err != nil {
return err
}
snapshot, release := view.Snapshot(ctx)
isGenerated := source.IsGenerated(ctx, snapshot, uri)
release()
if !isGenerated {
return nil
}
return s.client.ShowMessage(ctx, &protocol.ShowMessageParams{
Message: fmt.Sprintf("Do not edit this file! %s is a generated file.", uri.Filename()),
Type: protocol.Warning,
})
}
func (s *Server) didChangeWatchedFiles(ctx context.Context, params *protocol.DidChangeWatchedFilesParams) error {
var modifications []source.FileModification
for _, change := range params.Changes {
uri := change.URI.SpanURI()
if !uri.IsFile() {
continue
}
action := changeTypeToFileAction(change.Type)
modifications = append(modifications, source.FileModification{
URI: uri,
Action: action,
OnDisk: true,
})
}
return s.didModifyFiles(ctx, modifications, FromDidChangeWatchedFiles)
}
func (s *Server) didSave(ctx context.Context, params *protocol.DidSaveTextDocumentParams) error {
uri := params.TextDocument.URI.SpanURI()
if !uri.IsFile() {
return nil
}
c := source.FileModification{
URI: uri,
Action: source.Save,
}
if params.Text != nil {
c.Text = []byte(*params.Text)
}
return s.didModifyFiles(ctx, []source.FileModification{c}, FromDidSave)
}
func (s *Server) didClose(ctx context.Context, params *protocol.DidCloseTextDocumentParams) error {
uri := params.TextDocument.URI.SpanURI()
if !uri.IsFile() {
return nil
}
return s.didModifyFiles(ctx, []source.FileModification{
{
URI: uri,
Action: source.Close,
Version: -1,
Text: nil,
},
}, FromDidClose)
}
func (s *Server) didModifyFiles(ctx context.Context, modifications []source.FileModification, cause ModificationSource) error {
diagnoseDone := make(chan struct{})
if s.session.Options().VerboseWorkDoneProgress {
work := s.progress.Start(ctx, DiagnosticWorkTitle(cause), "Calculating file diagnostics...", nil, nil)
defer func() {
go func() {
<-diagnoseDone
work.End(ctx, "Done.")
}()
}()
}
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
}
// processModifications update server state to reflect file changes, and
// triggers diagnostics to run asynchronously. The diagnoseDone channel will be
// closed once diagnostics complete.
func (s *Server) processModifications(ctx context.Context, modifications []source.FileModification, onDisk bool, diagnoseDone chan struct{}) error {
s.stateMu.Lock()
if s.state >= serverShutDown {
// This state check does not prevent races below, and exists only to
// produce a better error message. The actual race to the cache should be
// guarded by Session.viewMu.
s.stateMu.Unlock()
close(diagnoseDone)
return errors.New("server is shut down")
}
s.stateMu.Unlock()
// If the set of changes included directories, expand those directories
// to their files.
modifications = s.session.ExpandModificationsToDirectories(ctx, modifications)
snapshots, release, err := s.session.DidModifyFiles(ctx, modifications)
if err != nil {
close(diagnoseDone)
return err
}
go func() {
s.diagnoseSnapshots(snapshots, onDisk)
release()
close(diagnoseDone)
}()
// After any file modifications, we need to update our watched files,
// in case something changed. Compute the new set of directories to watch,
// and if it differs from the current set, send updated registrations.
return s.updateWatchedDirectories(ctx)
}
// DiagnosticWorkTitle returns the title of the diagnostic work resulting from a
// file change originating from the given cause.
func DiagnosticWorkTitle(cause ModificationSource) string {
return fmt.Sprintf("diagnosing %v", cause)
}
func (s *Server) changedText(ctx context.Context, uri span.URI, changes []protocol.TextDocumentContentChangeEvent) ([]byte, error) {
if len(changes) == 0 {
return nil, fmt.Errorf("%w: no content changes provided", jsonrpc2.ErrInternal)
}
// Check if the client sent the full content of the file.
// We accept a full content change even if the server expected incremental changes.
if len(changes) == 1 && changes[0].Range == nil && changes[0].RangeLength == 0 {
return []byte(changes[0].Text), nil
}
return s.applyIncrementalChanges(ctx, uri, changes)
}
func (s *Server) applyIncrementalChanges(ctx context.Context, uri span.URI, changes []protocol.TextDocumentContentChangeEvent) ([]byte, error) {
fh, err := s.session.GetFile(ctx, uri)
if err != nil {
return nil, err
}
content, err := fh.Read()
if err != nil {
return nil, fmt.Errorf("%w: file not found (%v)", jsonrpc2.ErrInternal, err)
}
for _, change := range changes {
// Make sure to update column mapper along with the content.
m := protocol.NewColumnMapper(uri, content)
if change.Range == nil {
return nil, fmt.Errorf("%w: unexpected nil range for change", jsonrpc2.ErrInternal)
}
spn, err := m.RangeSpan(*change.Range)
if err != nil {
return nil, err
}
if !spn.HasOffset() {
return nil, fmt.Errorf("%w: invalid range for content change", jsonrpc2.ErrInternal)
}
start, end := spn.Start().Offset(), spn.End().Offset()
if end < start {
return nil, fmt.Errorf("%w: invalid range for content change", jsonrpc2.ErrInternal)
}
var buf bytes.Buffer
buf.Write(content[:start])
buf.WriteString(change.Text)
buf.Write(content[end:])
content = buf.Bytes()
}
return content, nil
}
func changeTypeToFileAction(ct protocol.FileChangeType) source.FileAction {
switch ct {
case protocol.Changed:
return source.Change
case protocol.Created:
return source.Create
case protocol.Deleted:
return source.Delete
}
return source.UnknownFileAction
}