blob: 3faa7e118552f522b973f606dff5fd9444b068bf [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 (
"bytes"
"context"
"fmt"
"go/ast"
"go/token"
"go/types"
"io"
"os"
"path/filepath"
"sort"
"strings"
"sync"
"golang.org/x/tools/go/analysis"
"golang.org/x/tools/go/packages"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/gocommand"
"golang.org/x/tools/internal/lsp/debug/tag"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/packagesinternal"
"golang.org/x/tools/internal/span"
"golang.org/x/tools/internal/typesinternal"
errors "golang.org/x/xerrors"
)
type snapshot struct {
id uint64
view *View
// mu guards all of the maps in the snapshot.
mu sync.Mutex
// ids maps file URIs to package IDs.
// It may be invalidated on calls to go/packages.
ids map[span.URI][]packageID
// metadata maps file IDs to their associated metadata.
// It may invalidated on calls to go/packages.
metadata map[packageID]*metadata
// importedBy maps package IDs to the list of packages that import them.
importedBy map[packageID][]packageID
// files maps file URIs to their corresponding FileHandles.
// It may invalidated when a file's content changes.
files map[span.URI]source.FileHandle
// packages maps a packageKey to a set of packageHandles to which that file belongs.
// It may be invalidated when a file's content changes.
packages map[packageKey]*packageHandle
// actions maps an actionkey to its actionHandle.
actions map[actionKey]*actionHandle
// workspacePackages contains the workspace's packages, which are loaded
// when the view is created.
workspacePackages map[packageID]packagePath
// unloadableFiles keeps track of files that we've failed to load.
unloadableFiles map[span.URI]struct{}
// parseModHandles keeps track of any ParseModHandles for the snapshot.
// The handles need not refer to only the view's go.mod file.
parseModHandles map[span.URI]*parseModHandle
// Preserve go.mod-related handles to avoid garbage-collecting the results
// of various calls to the go command.
//
// TODO(rstambler): If we end up with any more such handles, we should
// consider creating a struct for them.
modTidyHandle *modTidyHandle
modWhyHandle *modWhyHandle
modUpgradeHandle *modUpgradeHandle
}
type packageKey struct {
mode source.ParseMode
id packageID
}
type actionKey struct {
pkg packageKey
analyzer *analysis.Analyzer
}
func (s *snapshot) ID() uint64 {
return s.id
}
func (s *snapshot) View() source.View {
return s.view
}
// config returns the configuration used for the snapshot's interaction with the
// go/packages API.
func (s *snapshot) config(ctx context.Context) *packages.Config {
s.view.optionsMu.Lock()
env, buildFlags := s.view.envLocked()
verboseOutput := s.view.options.VerboseOutput
s.view.optionsMu.Unlock()
cfg := &packages.Config{
Env: env,
Dir: s.view.folder.Filename(),
Context: ctx,
BuildFlags: buildFlags,
Mode: packages.NeedName |
packages.NeedFiles |
packages.NeedCompiledGoFiles |
packages.NeedImports |
packages.NeedDeps |
packages.NeedTypesSizes |
packages.NeedModule,
Fset: s.view.session.cache.fset,
Overlay: s.buildOverlay(),
ParseFile: func(*token.FileSet, string, []byte) (*ast.File, error) {
panic("go/packages must not be used to parse files")
},
Logf: func(format string, args ...interface{}) {
if verboseOutput {
event.Log(ctx, fmt.Sprintf(format, args...))
}
},
Tests: true,
}
// We want to type check cgo code if go/types supports it.
if typesinternal.SetUsesCgo(&types.Config{}) {
cfg.Mode |= packages.LoadMode(packagesinternal.TypecheckCgo)
}
packagesinternal.SetGoCmdRunner(cfg, s.view.gocmdRunner)
return cfg
}
func (s *snapshot) RunGoCommandDirect(ctx context.Context, verb string, args []string) error {
cfg := s.config(ctx)
_, _, err := runGoCommand(ctx, cfg, nil, s.view.tmpMod, verb, args)
return err
}
func (s *snapshot) RunGoCommand(ctx context.Context, verb string, args []string) (*bytes.Buffer, error) {
cfg := s.config(ctx)
var pmh source.ParseModHandle
if s.view.tmpMod {
modFH, err := s.GetFile(ctx, s.view.modURI)
if err != nil {
return nil, err
}
pmh, err = s.ParseModHandle(ctx, modFH)
if err != nil {
return nil, err
}
}
_, stdout, err := runGoCommand(ctx, cfg, pmh, s.view.tmpMod, verb, args)
return stdout, err
}
func (s *snapshot) RunGoCommandPiped(ctx context.Context, verb string, args []string, stdout, stderr io.Writer) error {
cfg := s.config(ctx)
var pmh source.ParseModHandle
if s.view.tmpMod {
modFH, err := s.GetFile(ctx, s.view.modURI)
if err != nil {
return err
}
pmh, err = s.ParseModHandle(ctx, modFH)
if err != nil {
return err
}
}
_, inv, cleanup, err := goCommandInvocation(ctx, cfg, pmh, verb, args)
if err != nil {
return err
}
defer cleanup()
runner := packagesinternal.GetGoCmdRunner(cfg)
return runner.RunPiped(ctx, *inv, stdout, stderr)
}
// runGoCommand runs the given go command with the given config.
// The given go.mod file is used to construct the temporary go.mod file, which
// is then passed to the go command via the BuildFlags.
// It assumes that modURI is only provided when the -modfile flag is enabled.
func runGoCommand(ctx context.Context, cfg *packages.Config, pmh source.ParseModHandle, tmpMod bool, verb string, args []string) (span.URI, *bytes.Buffer, error) {
// Don't pass in the ParseModHandle if we are not using the -modfile flag.
var tmpPMH source.ParseModHandle
if tmpMod {
tmpPMH = pmh
}
tmpURI, inv, cleanup, err := goCommandInvocation(ctx, cfg, tmpPMH, verb, args)
if err != nil {
return "", nil, err
}
defer cleanup()
runner := packagesinternal.GetGoCmdRunner(cfg)
stdout, err := runner.Run(ctx, *inv)
return tmpURI, stdout, err
}
// Assumes that modURI is only provided when the -modfile flag is enabled.
func goCommandInvocation(ctx context.Context, cfg *packages.Config, pmh source.ParseModHandle, verb string, args []string) (tmpURI span.URI, inv *gocommand.Invocation, cleanup func(), err error) {
cleanup = func() {} // fallback
if pmh != nil {
tmpURI, cleanup, err = tempModFile(pmh.Mod(), pmh.Sum())
if err != nil {
return "", nil, nil, err
}
cfg.BuildFlags = append(cfg.BuildFlags, fmt.Sprintf("-modfile=%s", tmpURI.Filename()))
}
return tmpURI, &gocommand.Invocation{
Verb: verb,
Args: args,
Env: cfg.Env,
BuildFlags: cfg.BuildFlags,
WorkingDir: cfg.Dir,
}, cleanup, nil
}
func (s *snapshot) buildOverlay() map[string][]byte {
s.mu.Lock()
defer s.mu.Unlock()
overlays := make(map[string][]byte)
for uri, fh := range s.files {
overlay, ok := fh.(*overlay)
if !ok {
continue
}
if overlay.saved {
continue
}
// TODO(rstambler): Make sure not to send overlays outside of the current view.
overlays[uri.Filename()] = overlay.text
}
return overlays
}
func hashUnsavedOverlays(files map[span.URI]source.FileHandle) string {
var unsaved []string
for uri, fh := range files {
if overlay, ok := fh.(*overlay); ok && !overlay.saved {
unsaved = append(unsaved, uri.Filename())
}
}
sort.Strings(unsaved)
return hashContents([]byte(strings.Join(unsaved, "")))
}
func (s *snapshot) PackageHandles(ctx context.Context, fh source.FileHandle) ([]source.PackageHandle, error) {
if fh.Kind() != source.Go {
panic("called PackageHandles on a non-Go FileHandle")
}
ctx = event.Label(ctx, tag.URI.Of(fh.URI()))
// Check if we should reload metadata for the file. We don't invalidate IDs
// (though we should), so the IDs will be a better source of truth than the
// metadata. If there are no IDs for the file, then we should also reload.
ids := s.getIDsForURI(fh.URI())
reload := len(ids) == 0
for _, id := range ids {
// Reload package metadata if any of the metadata has missing
// dependencies, in case something has changed since the last time we
// reloaded it.
if m := s.getMetadata(id); m == nil {
reload = true
break
}
// TODO(golang/go#36918): Previously, we would reload any package with
// missing dependencies. This is expensive and results in too many
// calls to packages.Load. Determine what we should do instead.
}
if reload {
if err := s.load(ctx, fileURI(fh.URI())); err != nil {
return nil, err
}
}
// Get the list of IDs from the snapshot again, in case it has changed.
var phs []source.PackageHandle
for _, id := range s.getIDsForURI(fh.URI()) {
ph, err := s.packageHandle(ctx, id, source.ParseFull)
if err != nil {
return nil, err
}
phs = append(phs, ph)
}
return phs, nil
}
// packageHandle returns a PackageHandle for the given ID. It assumes that
// the metadata for the given ID has already been loaded, but if the
// PackageHandle has not been constructed, it will rebuild it.
func (s *snapshot) packageHandle(ctx context.Context, id packageID, mode source.ParseMode) (*packageHandle, error) {
ph := s.getPackage(id, mode)
if ph != nil {
return ph, nil
}
// Don't reload metadata in this function.
// Callers of this function must reload metadata themselves.
m := s.getMetadata(id)
if m == nil {
return nil, errors.Errorf("%s has no metadata", id)
}
return s.buildPackageHandle(ctx, m.id, mode)
}
func (s *snapshot) GetReverseDependencies(ctx context.Context, id string) ([]source.PackageHandle, error) {
if err := s.awaitLoaded(ctx); err != nil {
return nil, err
}
ids := make(map[packageID]struct{})
s.transitiveReverseDependencies(packageID(id), ids)
// Make sure to delete the original package ID from the map.
delete(ids, packageID(id))
var results []source.PackageHandle
for id := range ids {
ph, err := s.packageHandle(ctx, id, source.ParseFull)
if err != nil {
return nil, err
}
results = append(results, ph)
}
return results, nil
}
// transitiveReverseDependencies populates the uris map with file URIs
// belonging to the provided package and its transitive reverse dependencies.
func (s *snapshot) transitiveReverseDependencies(id packageID, ids map[packageID]struct{}) {
if _, ok := ids[id]; ok {
return
}
if s.getMetadata(id) == nil {
return
}
ids[id] = struct{}{}
importedBy := s.getImportedBy(id)
for _, parentID := range importedBy {
s.transitiveReverseDependencies(parentID, ids)
}
}
func (s *snapshot) getModHandle(uri span.URI) *parseModHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.parseModHandles[uri]
}
func (s *snapshot) getModWhyHandle() *modWhyHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.modWhyHandle
}
func (s *snapshot) getModUpgradeHandle() *modUpgradeHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.modUpgradeHandle
}
func (s *snapshot) getModTidyHandle() *modTidyHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.modTidyHandle
}
func (s *snapshot) getImportedBy(id packageID) []packageID {
s.mu.Lock()
defer s.mu.Unlock()
return s.getImportedByLocked(id)
}
func (s *snapshot) getImportedByLocked(id packageID) []packageID {
// If we haven't rebuilt the import graph since creating the snapshot.
if len(s.importedBy) == 0 {
s.rebuildImportGraph()
}
return s.importedBy[id]
}
func (s *snapshot) clearAndRebuildImportGraph() {
s.mu.Lock()
defer s.mu.Unlock()
// Completely invalidate the original map.
s.importedBy = make(map[packageID][]packageID)
s.rebuildImportGraph()
}
func (s *snapshot) rebuildImportGraph() {
for id, m := range s.metadata {
for _, importID := range m.deps {
s.importedBy[importID] = append(s.importedBy[importID], id)
}
}
}
func (s *snapshot) addPackageHandle(ph *packageHandle) *packageHandle {
s.mu.Lock()
defer s.mu.Unlock()
// If the package handle has already been cached,
// return the cached handle instead of overriding it.
if ph, ok := s.packages[ph.packageKey()]; ok {
return ph
}
s.packages[ph.packageKey()] = ph
return ph
}
func (s *snapshot) workspacePackageIDs() (ids []packageID) {
s.mu.Lock()
defer s.mu.Unlock()
for id := range s.workspacePackages {
ids = append(ids, id)
}
return ids
}
func (s *snapshot) WorkspacePackages(ctx context.Context) ([]source.PackageHandle, error) {
if err := s.awaitLoaded(ctx); err != nil {
return nil, err
}
var results []source.PackageHandle
for _, pkgID := range s.workspacePackageIDs() {
ph, err := s.packageHandle(ctx, pkgID, source.ParseFull)
if err != nil {
return nil, err
}
results = append(results, ph)
}
return results, nil
}
func (s *snapshot) KnownPackages(ctx context.Context) ([]source.PackageHandle, error) {
if err := s.awaitLoaded(ctx); err != nil {
return nil, err
}
// Collect PackageHandles for all of the workspace packages first.
// They may need to be reloaded if their metadata has been invalidated.
wsPackages := make(map[packageID]bool)
s.mu.Lock()
for id := range s.workspacePackages {
wsPackages[id] = true
}
s.mu.Unlock()
var results []source.PackageHandle
for pkgID := range wsPackages {
ph, err := s.packageHandle(ctx, pkgID, source.ParseFull)
if err != nil {
return nil, err
}
results = append(results, ph)
}
// Once all workspace packages have been checked, the metadata will be up-to-date.
// Add all packages known in the workspace (that haven't already been added).
pkgIDs := make(map[packageID]bool)
s.mu.Lock()
for id := range s.metadata {
if !wsPackages[id] {
pkgIDs[id] = true
}
}
s.mu.Unlock()
for pkgID := range pkgIDs {
// Metadata for these packages should already be up-to-date,
// so just build the package handle directly (without a reload).
ph, err := s.buildPackageHandle(ctx, pkgID, source.ParseExported)
if err != nil {
return nil, err
}
results = append(results, ph)
}
return results, nil
}
func (s *snapshot) CachedImportPaths(ctx context.Context) (map[string]source.Package, error) {
// Don't reload workspace package metadata.
// This function is meant to only return currently cached information.
s.view.awaitInitialized(ctx)
s.mu.Lock()
defer s.mu.Unlock()
results := map[string]source.Package{}
for _, ph := range s.packages {
cachedPkg, err := ph.cached()
if err != nil {
continue
}
for importPath, newPkg := range cachedPkg.imports {
if oldPkg, ok := results[string(importPath)]; ok {
// Using the same trick as NarrowestPackageHandle, prefer non-variants.
if len(newPkg.compiledGoFiles) < len(oldPkg.(*pkg).compiledGoFiles) {
results[string(importPath)] = newPkg
}
} else {
results[string(importPath)] = newPkg
}
}
}
return results, nil
}
func (s *snapshot) getPackage(id packageID, mode source.ParseMode) *packageHandle {
s.mu.Lock()
defer s.mu.Unlock()
key := packageKey{
id: id,
mode: mode,
}
return s.packages[key]
}
func (s *snapshot) getActionHandle(id packageID, m source.ParseMode, a *analysis.Analyzer) *actionHandle {
s.mu.Lock()
defer s.mu.Unlock()
key := actionKey{
pkg: packageKey{
id: id,
mode: m,
},
analyzer: a,
}
return s.actions[key]
}
func (s *snapshot) addActionHandle(ah *actionHandle) *actionHandle {
s.mu.Lock()
defer s.mu.Unlock()
key := actionKey{
analyzer: ah.analyzer,
pkg: packageKey{
id: ah.pkg.id,
mode: ah.pkg.mode,
},
}
if ah, ok := s.actions[key]; ok {
return ah
}
s.actions[key] = ah
return ah
}
func (s *snapshot) getIDsForURI(uri span.URI) []packageID {
s.mu.Lock()
defer s.mu.Unlock()
return s.ids[uri]
}
func (s *snapshot) getMetadataForURILocked(uri span.URI) (metadata []*metadata) {
// TODO(matloob): uri can be a file or directory. Should we update the mappings
// to map directories to their contained packages?
for _, id := range s.ids[uri] {
if m, ok := s.metadata[id]; ok {
metadata = append(metadata, m)
}
}
return metadata
}
func (s *snapshot) getMetadata(id packageID) *metadata {
s.mu.Lock()
defer s.mu.Unlock()
return s.metadata[id]
}
func (s *snapshot) addID(uri span.URI, id packageID) {
s.mu.Lock()
defer s.mu.Unlock()
for i, existingID := range s.ids[uri] {
// TODO: We should make sure not to set duplicate IDs,
// and instead panic here. This can be done by making sure not to
// reset metadata information for packages we've already seen.
if existingID == id {
return
}
// If we are setting a real ID, when the package had only previously
// had a command-line-arguments ID, we should just replace it.
if existingID == "command-line-arguments" {
s.ids[uri][i] = id
// Delete command-line-arguments if it was a workspace package.
delete(s.workspacePackages, existingID)
return
}
}
s.ids[uri] = append(s.ids[uri], id)
}
func (s *snapshot) isWorkspacePackage(id packageID) (packagePath, bool) {
s.mu.Lock()
defer s.mu.Unlock()
scope, ok := s.workspacePackages[id]
return scope, ok
}
func (s *snapshot) FindFile(uri span.URI) source.FileHandle {
f, err := s.view.getFile(uri)
if err != nil {
return nil
}
s.mu.Lock()
defer s.mu.Unlock()
return s.files[f.URI()]
}
// GetFile returns a File for the given URI. It will always succeed because it
// adds the file to the managed set if needed.
func (s *snapshot) GetFile(ctx context.Context, uri span.URI) (source.FileHandle, error) {
f, err := s.view.getFile(uri)
if err != nil {
return nil, err
}
s.mu.Lock()
defer s.mu.Unlock()
if fh, ok := s.files[f.URI()]; ok {
return fh, nil
}
fh, err := s.view.session.cache.getFile(ctx, uri)
if err != nil {
return nil, err
}
s.files[f.URI()] = fh
return fh, nil
}
func (s *snapshot) IsOpen(uri span.URI) bool {
s.mu.Lock()
defer s.mu.Unlock()
_, open := s.files[uri].(*overlay)
return open
}
func (s *snapshot) IsSaved(uri span.URI) bool {
s.mu.Lock()
defer s.mu.Unlock()
ovl, open := s.files[uri].(*overlay)
return !open || ovl.saved
}
func (s *snapshot) awaitLoaded(ctx context.Context) error {
// Do not return results until the snapshot's view has been initialized.
s.view.awaitInitialized(ctx)
if err := s.reloadWorkspace(ctx); err != nil {
return err
}
if err := s.reloadOrphanedFiles(ctx); err != nil {
return err
}
// If we still have absolutely no metadata, check if the view failed to
// initialize and return any errors.
// TODO(rstambler): Should we clear the error after we return it?
s.mu.Lock()
defer s.mu.Unlock()
if len(s.metadata) == 0 {
return s.view.initializedErr
}
return nil
}
// reloadWorkspace reloads the metadata for all invalidated workspace packages.
func (s *snapshot) reloadWorkspace(ctx context.Context) error {
// If the view's build configuration is invalid, we cannot reload by package path.
// Just reload the directory instead.
if !s.view.hasValidBuildConfiguration {
return s.load(ctx, viewLoadScope("LOAD_INVALID_VIEW"))
}
// See which of the workspace packages are missing metadata.
s.mu.Lock()
var pkgPaths []interface{}
for id, pkgPath := range s.workspacePackages {
// Don't try to reload "command-line-arguments" directly.
if pkgPath == "command-line-arguments" {
continue
}
if s.metadata[id] == nil {
pkgPaths = append(pkgPaths, pkgPath)
}
}
s.mu.Unlock()
if len(pkgPaths) == 0 {
return nil
}
return s.load(ctx, pkgPaths...)
}
func (s *snapshot) reloadOrphanedFiles(ctx context.Context) error {
// When we load ./... or a package path directly, we may not get packages
// that exist only in overlays. As a workaround, we search all of the files
// available in the snapshot and reload their metadata individually using a
// file= query if the metadata is unavailable.
scopes := s.orphanedFileScopes()
if len(scopes) == 0 {
return nil
}
err := s.load(ctx, scopes...)
// If we failed to load some files, i.e. they have no metadata,
// mark the failures so we don't bother retrying until the file's
// content changes.
//
// TODO(rstambler): This may be an overestimate if the load stopped
// early for an unrelated errors. Add a fallback?
//
// Check for context cancellation so that we don't incorrectly mark files
// as unloadable, but don't return before setting all workspace packages.
if ctx.Err() == nil && err != nil {
event.Error(ctx, "reloadOrphanedFiles: failed to load", err, tag.Query.Of(scopes))
s.mu.Lock()
for _, scope := range scopes {
uri := span.URI(scope.(fileURI))
if s.getMetadataForURILocked(uri) == nil {
s.unloadableFiles[uri] = struct{}{}
}
}
s.mu.Unlock()
}
return nil
}
func (s *snapshot) orphanedFileScopes() []interface{} {
s.mu.Lock()
defer s.mu.Unlock()
scopeSet := make(map[span.URI]struct{})
for uri, fh := range s.files {
// Don't try to reload metadata for go.mod files.
if fh.Kind() != source.Go {
continue
}
// If the URI doesn't belong to this view, then it's not in a workspace
// package and should not be reloaded directly.
if !contains(s.view.session.viewsOf(uri), s.view) {
continue
}
// Don't reload metadata for files we've already deemed unloadable.
if _, ok := s.unloadableFiles[uri]; ok {
continue
}
if s.getMetadataForURILocked(uri) == nil {
scopeSet[uri] = struct{}{}
}
}
var scopes []interface{}
for uri := range scopeSet {
scopes = append(scopes, fileURI(uri))
}
return scopes
}
func contains(views []*View, view *View) bool {
for _, v := range views {
if v == view {
return true
}
}
return false
}
func (s *snapshot) clone(ctx context.Context, withoutURIs map[span.URI]source.FileHandle, forceReloadMetadata bool) *snapshot {
s.mu.Lock()
defer s.mu.Unlock()
result := &snapshot{
id: s.id + 1,
view: s.view,
ids: make(map[span.URI][]packageID),
importedBy: make(map[packageID][]packageID),
metadata: make(map[packageID]*metadata),
packages: make(map[packageKey]*packageHandle),
actions: make(map[actionKey]*actionHandle),
files: make(map[span.URI]source.FileHandle),
workspacePackages: make(map[packageID]packagePath),
unloadableFiles: make(map[span.URI]struct{}),
parseModHandles: make(map[span.URI]*parseModHandle),
modTidyHandle: s.modTidyHandle,
modUpgradeHandle: s.modUpgradeHandle,
modWhyHandle: s.modWhyHandle,
}
// Copy all of the FileHandles.
for k, v := range s.files {
result.files[k] = v
}
// Copy the set of unloadable files.
for k, v := range s.unloadableFiles {
result.unloadableFiles[k] = v
}
// Copy all of the modHandles.
for k, v := range s.parseModHandles {
result.parseModHandles[k] = v
}
// transitiveIDs keeps track of transitive reverse dependencies.
// If an ID is present in the map, invalidate its types.
// If an ID's value is true, invalidate its metadata too.
transitiveIDs := make(map[packageID]bool)
for withoutURI, currentFH := range withoutURIs {
directIDs := map[packageID]struct{}{}
// Collect all of the package IDs that correspond to the given file.
// TODO: if the file has moved into a new package, we should invalidate that too.
for _, id := range s.ids[withoutURI] {
directIDs[id] = struct{}{}
}
// The original FileHandle for this URI is cached on the snapshot.
originalFH := s.files[withoutURI]
// Check if the file's package name or imports have changed,
// and if so, invalidate this file's packages' metadata.
invalidateMetadata := forceReloadMetadata || s.shouldInvalidateMetadata(ctx, originalFH, currentFH)
// Invalidate the previous modTidyHandle if any of the files have been
// saved or if any of the metadata has been invalidated.
if invalidateMetadata || fileWasSaved(originalFH, currentFH) {
result.modTidyHandle = nil
result.modUpgradeHandle = nil
result.modWhyHandle = nil
}
if currentFH.Kind() == source.Mod {
// If the view's go.mod file's contents have changed, invalidate the metadata
// for all of the packages in the workspace.
if invalidateMetadata {
for id := range s.workspacePackages {
directIDs[id] = struct{}{}
}
}
delete(result.parseModHandles, withoutURI)
}
// If this is a file we don't yet know about,
// then we do not yet know what packages it should belong to.
// Make a rough estimate of what metadata to invalidate by finding the package IDs
// of all of the files in the same directory as this one.
// TODO(rstambler): Speed this up by mapping directories to filenames.
if len(directIDs) == 0 {
if dirStat, err := os.Stat(filepath.Dir(withoutURI.Filename())); err == nil {
for uri := range s.files {
if fdirStat, err := os.Stat(filepath.Dir(uri.Filename())); err == nil {
if os.SameFile(dirStat, fdirStat) {
for _, id := range s.ids[uri] {
directIDs[id] = struct{}{}
}
}
}
}
}
}
// Invalidate reverse dependencies too.
// TODO(heschi): figure out the locking model and use transitiveReverseDeps?
var addRevDeps func(packageID)
addRevDeps = func(id packageID) {
if _, seen := transitiveIDs[id]; seen {
return
}
transitiveIDs[id] = invalidateMetadata
for _, rid := range s.getImportedByLocked(id) {
addRevDeps(rid)
}
}
for id := range directIDs {
addRevDeps(id)
}
// Handle the invalidated file; it may have new contents or not exist.
if _, err := currentFH.Read(); os.IsNotExist(err) {
delete(result.files, withoutURI)
} else {
result.files[withoutURI] = currentFH
}
// Make sure to remove the changed file from the unloadable set.
delete(result.unloadableFiles, withoutURI)
}
// Copy the package type information.
for k, v := range s.packages {
if _, ok := transitiveIDs[k.id]; ok {
continue
}
result.packages[k] = v
}
// Copy the package analysis information.
for k, v := range s.actions {
if _, ok := transitiveIDs[k.pkg.id]; ok {
continue
}
result.actions[k] = v
}
// Copy the package metadata. We only need to invalidate packages directly
// containing the affected file, and only if it changed in a relevant way.
for k, v := range s.metadata {
if invalidateMetadata, ok := transitiveIDs[k]; invalidateMetadata && ok {
continue
}
result.metadata[k] = v
}
// Copy the URI to package ID mappings, skipping only those URIs whose
// metadata will be reloaded in future calls to load.
copyIDs:
for k, ids := range s.ids {
for _, id := range ids {
if invalidateMetadata, ok := transitiveIDs[id]; invalidateMetadata && ok {
continue copyIDs
}
}
result.ids[k] = ids
}
// Copy the set of initally loaded packages.
for id, pkgPath := range s.workspacePackages {
if id == "command-line-arguments" {
if invalidateMetadata, ok := transitiveIDs[id]; invalidateMetadata && ok {
continue
}
}
// If all the files we know about in a package have been deleted,
// the package is gone and we should no longer try to load it.
if m := s.metadata[id]; m != nil {
hasFiles := false
for _, uri := range s.metadata[id].goFiles {
if _, ok := result.files[uri]; ok {
hasFiles = true
break
}
}
if !hasFiles {
continue
}
}
result.workspacePackages[id] = pkgPath
}
// Don't bother copying the importedBy graph,
// as it changes each time we update metadata.
return result
}
// fileWasSaved reports whether the FileHandle passed in has been saved. It
// accomplishes this by checking to see if the original and current FileHandles
// are both overlays, and if the current FileHandle is saved while the original
// FileHandle was not saved.
func fileWasSaved(originalFH, currentFH source.FileHandle) bool {
c, ok := currentFH.(*overlay)
if !ok || c == nil {
return true
}
o, ok := originalFH.(*overlay)
if !ok || o == nil {
return c.saved
}
return !o.saved && c.saved
}
// shouldInvalidateMetadata reparses a file's package and import declarations to
// determine if the file requires a metadata reload.
func (s *snapshot) shouldInvalidateMetadata(ctx context.Context, originalFH, currentFH source.FileHandle) bool {
if originalFH == nil {
return currentFH.Kind() == source.Go
}
// If the file hasn't changed, there's no need to reload.
if originalFH.Identity().String() == currentFH.Identity().String() {
return false
}
// If a go.mod file's contents have changed, always invalidate metadata.
if kind := originalFH.Kind(); kind == source.Mod {
return originalFH.URI() == s.view.modURI
}
// Get the original and current parsed files in order to check package name and imports.
original, _, _, _, originalErr := s.view.session.cache.ParseGoHandle(ctx, originalFH, source.ParseHeader).Parse(ctx)
current, _, _, _, currentErr := s.view.session.cache.ParseGoHandle(ctx, currentFH, source.ParseHeader).Parse(ctx)
if originalErr != nil || currentErr != nil {
return (originalErr == nil) != (currentErr == nil)
}
// Check if the package's metadata has changed. The cases handled are:
// 1. A package's name has changed
// 2. A file's imports have changed
if original.Name.Name != current.Name.Name {
return true
}
// If the package's imports have increased, definitely re-run `go list`.
if len(original.Imports) < len(current.Imports) {
return true
}
importSet := make(map[string]struct{})
for _, importSpec := range original.Imports {
importSet[importSpec.Path.Value] = struct{}{}
}
// If any of the current imports were not in the original imports.
for _, importSpec := range current.Imports {
if _, ok := importSet[importSpec.Path.Value]; !ok {
return true
}
}
return false
}