internal/lsp/cache: factor out guessPackagesForURI from snapshot.clone
To simplify snapshot.clone a bit, factor out the logic to figure out
which packages to invalidate when a new file arrives. This also made it
easier to improve the algorithm by caching os.Stat results when walking
known packages.
Change-Id: I012b60e8ad73eb4df80950aac48791204877e9e0
Reviewed-on: https://go-review.googlesource.com/c/tools/+/263204
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
Trust: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
diff --git a/internal/lsp/cache/snapshot.go b/internal/lsp/cache/snapshot.go
index ae45f7d..7659432 100644
--- a/internal/lsp/cache/snapshot.go
+++ b/internal/lsp/cache/snapshot.go
@@ -1072,11 +1072,13 @@
for withoutURI, currentFH := range withoutURIs {
directIDs := map[packageID]struct{}{}
+ filePackages := guessPackagesForURI(withoutURI, s.ids)
// 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] {
+ for _, id := range filePackages {
directIDs[id] = struct{}{}
}
+
// The original FileHandle for this URI is cached on the snapshot.
originalFH := s.files[withoutURI]
@@ -1160,25 +1162,6 @@
}
}
- // 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)
@@ -1316,6 +1299,56 @@
return result, reinitialize
}
+// guessPackagesForURI returns all packages related to uri. If we haven't seen this
+// URI before, we guess based on files in the same directory. This is of course
+// incorrect in build systems where packages are not organized by directory.
+func guessPackagesForURI(uri span.URI, known map[span.URI][]packageID) []packageID {
+ packages := known[uri]
+ if len(packages) > 0 {
+ // We've seen this file before.
+ return packages
+ }
+ // This is a file we don't yet know about. Guess relevant packages by
+ // considering files in the same directory.
+
+ // Cache of FileInfo to avoid unnecessary stats for multiple files in the
+ // same directory.
+ stats := make(map[string]struct {
+ os.FileInfo
+ error
+ })
+ getInfo := func(dir string) (os.FileInfo, error) {
+ if res, ok := stats[dir]; ok {
+ return res.FileInfo, res.error
+ }
+ fi, err := os.Stat(dir)
+ stats[dir] = struct {
+ os.FileInfo
+ error
+ }{fi, err}
+ return fi, err
+ }
+ dir := filepath.Dir(uri.Filename())
+ fi, err := getInfo(dir)
+ if err != nil {
+ return nil
+ }
+
+ // Aggregate all possibly relevant package IDs.
+ var found []packageID
+ for knownURI, ids := range known {
+ knownDir := filepath.Dir(knownURI.Filename())
+ knownFI, err := getInfo(knownDir)
+ if err != nil {
+ continue
+ }
+ if os.SameFile(fi, knownFI) {
+ found = append(found, ids...)
+ }
+ }
+ return found
+}
+
type reinitializeView int
const (
