blob: 070bc5fdff1c6169846e818996d1f72ef5f35ca5 [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 cache
import (
"context"
"fmt"
"os"
"path/filepath"
"strconv"
"strings"
"sync"
"sync/atomic"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/gocommand"
"golang.org/x/tools/internal/imports"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/span"
"golang.org/x/tools/internal/xcontext"
errors "golang.org/x/xerrors"
)
type Session struct {
cache *Cache
id string
options *source.Options
viewMu sync.Mutex
views []*View
viewMap map[span.URI]*View
overlayMu sync.Mutex
overlays map[span.URI]*overlay
// gocmdRunner guards go command calls from concurrency errors.
gocmdRunner *gocommand.Runner
}
type overlay struct {
session *Session
uri span.URI
text []byte
hash string
version float64
kind source.FileKind
// saved is true if a file matches the state on disk,
// and therefore does not need to be part of the overlay sent to go/packages.
saved bool
}
func (o *overlay) Read() ([]byte, error) {
return o.text, nil
}
func (o *overlay) FileIdentity() source.FileIdentity {
return source.FileIdentity{
URI: o.uri,
Hash: o.hash,
Kind: o.kind,
}
}
func (o *overlay) VersionedFileIdentity() source.VersionedFileIdentity {
return source.VersionedFileIdentity{
URI: o.uri,
SessionID: o.session.id,
Version: o.version,
}
}
func (o *overlay) Kind() source.FileKind {
return o.kind
}
func (o *overlay) URI() span.URI {
return o.uri
}
func (o *overlay) Version() float64 {
return o.version
}
func (o *overlay) Session() string {
return o.session.id
}
func (o *overlay) Saved() bool {
return o.saved
}
// closedFile implements LSPFile for a file that the editor hasn't told us about.
type closedFile struct {
source.FileHandle
}
func (c *closedFile) VersionedFileIdentity() source.VersionedFileIdentity {
return source.VersionedFileIdentity{
URI: c.FileHandle.URI(),
SessionID: "",
Version: 0,
}
}
func (c *closedFile) Session() string {
return ""
}
func (c *closedFile) Version() float64 {
return 0
}
func (s *Session) ID() string { return s.id }
func (s *Session) String() string { return s.id }
func (s *Session) Options() *source.Options {
return s.options
}
func (s *Session) SetOptions(options *source.Options) {
s.options = options
}
func (s *Session) Shutdown(ctx context.Context) {
s.viewMu.Lock()
defer s.viewMu.Unlock()
for _, view := range s.views {
view.shutdown(ctx)
}
s.views = nil
s.viewMap = nil
event.Log(ctx, "Shutdown session", KeyShutdownSession.Of(s))
}
func (s *Session) Cache() interface{} {
return s.cache
}
func (s *Session) NewView(ctx context.Context, name string, folder span.URI, options *source.Options) (source.View, source.Snapshot, func(), error) {
s.viewMu.Lock()
defer s.viewMu.Unlock()
view, snapshot, release, err := s.createView(ctx, name, folder, options, 0)
if err != nil {
return nil, nil, func() {}, err
}
s.views = append(s.views, view)
// we always need to drop the view map
s.viewMap = make(map[span.URI]*View)
return view, snapshot, release, nil
}
func (s *Session) createView(ctx context.Context, name string, folder span.URI, options *source.Options, snapshotID uint64) (*View, *snapshot, func(), error) {
index := atomic.AddInt64(&viewIndex, 1)
// We want a true background context and not a detached context here
// the spans need to be unrelated and no tag values should pollute it.
baseCtx := event.Detach(xcontext.Detach(ctx))
backgroundCtx, cancel := context.WithCancel(baseCtx)
v := &View{
session: s,
initialized: make(chan struct{}),
initializationSema: make(chan struct{}, 1),
initializeOnce: &sync.Once{},
id: strconv.FormatInt(index, 10),
options: options,
baseCtx: baseCtx,
backgroundCtx: backgroundCtx,
cancel: cancel,
name: name,
folder: folder,
root: folder,
modules: make(map[span.URI]*moduleRoot),
filesByURI: make(map[span.URI]*fileBase),
filesByBase: make(map[string][]*fileBase),
}
v.snapshot = &snapshot{
id: snapshotID,
view: v,
generation: s.cache.store.Generation(generationName(v, 0)),
packages: make(map[packageKey]*packageHandle),
ids: make(map[span.URI][]packageID),
metadata: make(map[packageID]*metadata),
files: make(map[span.URI]source.VersionedFileHandle),
goFiles: make(map[parseKey]*parseGoHandle),
importedBy: make(map[packageID][]packageID),
actions: make(map[actionKey]*actionHandle),
workspacePackages: make(map[packageID]packagePath),
unloadableFiles: make(map[span.URI]struct{}),
parseModHandles: make(map[span.URI]*parseModHandle),
modTidyHandles: make(map[span.URI]*modTidyHandle),
modUpgradeHandles: make(map[span.URI]*modUpgradeHandle),
modWhyHandles: make(map[span.URI]*modWhyHandle),
}
if v.session.cache.options != nil {
v.session.cache.options(v.options)
}
// Set the module-specific information.
if err := v.setBuildInformation(ctx, options); err != nil {
return nil, nil, func() {}, err
}
// Find all of the modules in the workspace.
if err := v.findWorkspaceModules(ctx, options); err != nil {
return nil, nil, func() {}, err
}
// Now that we have set all required fields,
// check if the view has a valid build configuration.
v.setBuildConfiguration()
// Build the workspace module, if needed.
if options.ExperimentalWorkspaceModule {
if err := v.buildWorkspaceModule(ctx); err != nil {
return nil, nil, func() {}, err
}
}
// We have v.goEnv now.
v.processEnv = &imports.ProcessEnv{
GocmdRunner: s.gocmdRunner,
WorkingDir: folder.Filename(),
Env: v.goEnv,
}
// Set the first snapshot's workspace directories. The view's modURI was
// set by setBuildInformation.
var fh source.FileHandle
if v.modURI != "" {
fh, _ = s.GetFile(ctx, v.modURI)
}
v.snapshot.workspaceDirectories = v.snapshot.findWorkspaceDirectories(ctx, fh)
// Initialize the view without blocking.
initCtx, initCancel := context.WithCancel(xcontext.Detach(ctx))
v.initCancelFirstAttempt = initCancel
go func() {
release := v.snapshot.generation.Acquire(initCtx)
v.initialize(initCtx, v.snapshot, true)
release()
}()
return v, v.snapshot, v.snapshot.generation.Acquire(ctx), nil
}
// findWorkspaceModules walks the view's root folder, looking for go.mod files.
// Any that are found are added to the view's set of modules, which are then
// used to construct the workspace module.
//
// It assumes that the caller has not yet created the view, and therefore does
// not lock any of the internal data structures before accessing them.
func (v *View) findWorkspaceModules(ctx context.Context, options *source.Options) error {
// If the user is intentionally limiting their workspace scope, add their
// folder to the roots and return early.
if !options.ExpandWorkspaceToModule {
return nil
}
// The workspace module has been disabled by the user.
if !options.ExperimentalWorkspaceModule {
return nil
}
// Walk the view's folder to find all modules in the view.
root := v.root.Filename()
return filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
// For any path that is not the workspace folder, check if the path
// would be ignored by the go command. Vendor directories also do not
// contain workspace modules.
if info.IsDir() && path != root {
suffix := strings.TrimPrefix(path, root)
switch {
case checkIgnored(suffix),
strings.Contains(filepath.ToSlash(suffix), "/vendor/"):
return filepath.SkipDir
}
}
// We're only interested in go.mod files.
if filepath.Base(path) != "go.mod" {
return nil
}
// At this point, we definitely have a go.mod file in the workspace,
// so add it to the view.
modURI := span.URIFromPath(path)
rootURI := span.URIFromPath(filepath.Dir(path))
v.modules[rootURI] = &moduleRoot{
rootURI: rootURI,
modURI: modURI,
sumURI: span.URIFromPath(sumFilename(modURI)),
}
return nil
})
}
func (v *View) buildWorkspaceModule(ctx context.Context) error {
// If the view has an invalid configuration, don't build the workspace
// module.
if !v.hasValidBuildConfiguration {
return nil
}
// If the view is not in a module and contains no modules, but still has a
// valid workspace configuration, do not create the workspace module.
// It could be using GOPATH or a different build system entirely.
if v.modURI == "" && len(v.modules) == 0 && v.hasValidBuildConfiguration {
return nil
}
v.workspaceMode |= moduleMode
// Don't default to multi-workspace mode if one of the modules contains a
// vendor directory. We still have to decide how to handle vendoring.
for _, mod := range v.modules {
if info, _ := os.Stat(filepath.Join(mod.rootURI.Filename(), "vendor")); info != nil {
return nil
}
}
v.workspaceMode |= usesWorkspaceModule
// If the user does not have a gopls.mod, we need to create one, based on
// modules we found in the user's workspace.
var err error
v.workspaceModule, err = v.snapshot.buildWorkspaceModule(ctx)
return err
}
// View returns the view by name.
func (s *Session) View(name string) source.View {
s.viewMu.Lock()
defer s.viewMu.Unlock()
for _, view := range s.views {
if view.Name() == name {
return view
}
}
return nil
}
// ViewOf returns a view corresponding to the given URI.
// If the file is not already associated with a view, pick one using some heuristics.
func (s *Session) ViewOf(uri span.URI) (source.View, error) {
return s.viewOf(uri)
}
func (s *Session) viewOf(uri span.URI) (*View, error) {
s.viewMu.Lock()
defer s.viewMu.Unlock()
// Check if we already know this file.
if v, found := s.viewMap[uri]; found {
return v, nil
}
// Pick the best view for this file and memoize the result.
v, err := s.bestView(uri)
if err != nil {
return nil, err
}
s.viewMap[uri] = v
return v, nil
}
func (s *Session) viewsOf(uri span.URI) []*View {
s.viewMu.Lock()
defer s.viewMu.Unlock()
var views []*View
for _, view := range s.views {
if strings.HasPrefix(string(uri), string(view.Folder())) {
views = append(views, view)
}
}
return views
}
func (s *Session) Views() []source.View {
s.viewMu.Lock()
defer s.viewMu.Unlock()
result := make([]source.View, len(s.views))
for i, v := range s.views {
result[i] = v
}
return result
}
// bestView finds the best view to associate a given URI with.
// viewMu must be held when calling this method.
func (s *Session) bestView(uri span.URI) (*View, error) {
if len(s.views) == 0 {
return nil, errors.Errorf("no views in the session")
}
// we need to find the best view for this file
var longest *View
for _, view := range s.views {
if longest != nil && len(longest.Folder()) > len(view.Folder()) {
continue
}
if view.contains(uri) {
longest = view
}
}
if longest != nil {
return longest, nil
}
// Try our best to return a view that knows the file.
for _, view := range s.views {
if view.knownFile(uri) {
return view, nil
}
}
// TODO: are there any more heuristics we can use?
return s.views[0], nil
}
func (s *Session) removeView(ctx context.Context, view *View) error {
s.viewMu.Lock()
defer s.viewMu.Unlock()
i, err := s.dropView(ctx, view)
if err != nil {
return err
}
// delete this view... we don't care about order but we do want to make
// sure we can garbage collect the view
s.views[i] = s.views[len(s.views)-1]
s.views[len(s.views)-1] = nil
s.views = s.views[:len(s.views)-1]
return nil
}
func (s *Session) updateView(ctx context.Context, view *View, options *source.Options) (*View, error) {
s.viewMu.Lock()
defer s.viewMu.Unlock()
i, err := s.dropView(ctx, view)
if err != nil {
return nil, err
}
// Preserve the snapshot ID if we are recreating the view.
view.snapshotMu.Lock()
snapshotID := view.snapshot.id
view.snapshotMu.Unlock()
v, _, release, err := s.createView(ctx, view.name, view.folder, options, snapshotID)
release()
if err != nil {
// we have dropped the old view, but could not create the new one
// this should not happen and is very bad, but we still need to clean
// up the view array if it happens
s.views[i] = s.views[len(s.views)-1]
s.views[len(s.views)-1] = nil
s.views = s.views[:len(s.views)-1]
return nil, err
}
// substitute the new view into the array where the old view was
s.views[i] = v
return v, nil
}
func (s *Session) dropView(ctx context.Context, v *View) (int, error) {
// we always need to drop the view map
s.viewMap = make(map[span.URI]*View)
for i := range s.views {
if v == s.views[i] {
// we found the view, drop it and return the index it was found at
s.views[i] = nil
v.shutdown(ctx)
return i, nil
}
}
return -1, errors.Errorf("view %s for %v not found", v.Name(), v.Folder())
}
func (s *Session) ModifyFiles(ctx context.Context, changes []source.FileModification) error {
_, releases, _, err := s.DidModifyFiles(ctx, changes)
for _, release := range releases {
release()
}
return err
}
func (s *Session) DidModifyFiles(ctx context.Context, changes []source.FileModification) ([]source.Snapshot, []func(), []span.URI, error) {
views := make(map[*View]map[span.URI]source.VersionedFileHandle)
// Keep track of deleted files so that we can clear their diagnostics.
// A file might be re-created after deletion, so only mark files that
// have truly been deleted.
deletions := map[span.URI]struct{}{}
overlays, err := s.updateOverlays(ctx, changes)
if err != nil {
return nil, nil, nil, err
}
var forceReloadMetadata bool
for _, c := range changes {
if c.Action == source.InvalidateMetadata {
forceReloadMetadata = true
}
// Look through all of the session's views, invalidating the file for
// all of the views to which it is known.
for _, view := range s.views {
// Don't propagate changes that are outside of the view's scope
// or knowledge.
if !view.relevantChange(c) {
continue
}
// Make sure that the file is added to the view.
if _, err := view.getFile(c.URI); err != nil {
return nil, nil, nil, err
}
if _, ok := views[view]; !ok {
views[view] = make(map[span.URI]source.VersionedFileHandle)
}
var (
fh source.VersionedFileHandle
ok bool
)
if fh, ok = overlays[c.URI]; ok {
views[view][c.URI] = fh
delete(deletions, c.URI)
} else {
fsFile, err := s.cache.getFile(ctx, c.URI)
if err != nil {
return nil, nil, nil, err
}
fh = &closedFile{fsFile}
views[view][c.URI] = fh
if _, err := fh.Read(); err != nil {
deletions[c.URI] = struct{}{}
}
}
// If the file change is to a go.mod file, and initialization for
// the view has previously failed, we should attempt to retry.
// TODO(rstambler): We can use unsaved contents with -modfile, so
// maybe we should do that and retry on any change?
if fh.Kind() == source.Mod && (c.OnDisk || c.Action == source.Save) {
view.maybeReinitialize()
}
}
}
var snapshots []source.Snapshot
var releases []func()
for view, uris := range views {
snapshot, release := view.invalidateContent(ctx, uris, forceReloadMetadata)
snapshots = append(snapshots, snapshot)
releases = append(releases, release)
}
var deletionsSlice []span.URI
for uri := range deletions {
deletionsSlice = append(deletionsSlice, uri)
}
return snapshots, releases, deletionsSlice, nil
}
func (s *Session) isOpen(uri span.URI) bool {
s.overlayMu.Lock()
defer s.overlayMu.Unlock()
_, open := s.overlays[uri]
return open
}
func (s *Session) updateOverlays(ctx context.Context, changes []source.FileModification) (map[span.URI]*overlay, error) {
s.overlayMu.Lock()
defer s.overlayMu.Unlock()
for _, c := range changes {
// Don't update overlays for metadata invalidations.
if c.Action == source.InvalidateMetadata {
continue
}
o, ok := s.overlays[c.URI]
// If the file is not opened in an overlay and the change is on disk,
// there's no need to update an overlay. If there is an overlay, we
// may need to update the overlay's saved value.
if !ok && c.OnDisk {
continue
}
// Determine the file kind on open, otherwise, assume it has been cached.
var kind source.FileKind
switch c.Action {
case source.Open:
kind = source.DetectLanguage(c.LanguageID, c.URI.Filename())
default:
if !ok {
return nil, errors.Errorf("updateOverlays: modifying unopened overlay %v", c.URI)
}
kind = o.kind
}
if kind == source.UnknownKind {
return nil, errors.Errorf("updateOverlays: unknown file kind for %s", c.URI)
}
// Closing a file just deletes its overlay.
if c.Action == source.Close {
delete(s.overlays, c.URI)
continue
}
// If the file is on disk, check if its content is the same as in the
// overlay. Saves and on-disk file changes don't come with the file's
// content.
text := c.Text
if text == nil && (c.Action == source.Save || c.OnDisk) {
if !ok {
return nil, fmt.Errorf("no known content for overlay for %s", c.Action)
}
text = o.text
}
// On-disk changes don't come with versions.
version := c.Version
if c.OnDisk {
version = o.version
}
hash := hashContents(text)
var sameContentOnDisk bool
switch c.Action {
case source.Delete:
// Do nothing. sameContentOnDisk should be false.
case source.Save:
// Make sure the version and content (if present) is the same.
if o.version != version {
return nil, errors.Errorf("updateOverlays: saving %s at version %v, currently at %v", c.URI, c.Version, o.version)
}
if c.Text != nil && o.hash != hash {
return nil, errors.Errorf("updateOverlays: overlay %s changed on save", c.URI)
}
sameContentOnDisk = true
default:
fh, err := s.cache.getFile(ctx, c.URI)
if err != nil {
return nil, err
}
_, readErr := fh.Read()
sameContentOnDisk = (readErr == nil && fh.FileIdentity().Hash == hash)
}
o = &overlay{
session: s,
uri: c.URI,
version: version,
text: text,
kind: kind,
hash: hash,
saved: sameContentOnDisk,
}
s.overlays[c.URI] = o
}
// Get the overlays for each change while the session's overlay map is
// locked.
overlays := make(map[span.URI]*overlay)
for _, c := range changes {
if o, ok := s.overlays[c.URI]; ok {
overlays[c.URI] = o
}
}
return overlays, nil
}
func (s *Session) GetFile(ctx context.Context, uri span.URI) (source.FileHandle, error) {
if overlay := s.readOverlay(uri); overlay != nil {
return overlay, nil
}
// Fall back to the cache-level file system.
return s.cache.getFile(ctx, uri)
}
func (s *Session) readOverlay(uri span.URI) *overlay {
s.overlayMu.Lock()
defer s.overlayMu.Unlock()
if overlay, ok := s.overlays[uri]; ok {
return overlay
}
return nil
}
func (s *Session) Overlays() []source.Overlay {
s.overlayMu.Lock()
defer s.overlayMu.Unlock()
overlays := make([]source.Overlay, 0, len(s.overlays))
for _, overlay := range s.overlays {
overlays = append(overlays, overlay)
}
return overlays
}