Use filepath.WalkDir instead of filepath.Walk (#1210)

This has the benefit of not having to stat all files along the way.

Ideally, we'd be able to build the data bundle in the same function
more efficiently too, but that's a more complex operation.

Signed-off-by: Anders Eknert <[email protected]>

internal/lsp/bundles/cache.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 
 	"github.com/open-policy-agent/opa/bundle"
@@ -144,14 +145,20 @@ type cacheBundle struct {
 func (c *cacheBundle) Refresh(path string) (bool, error) {
 	onDiskSourceDigests := make(map[string][]byte)
 
+	filter := []string{".manifest", "data.json", "data.yml", "data.yaml"}
+
 	// walk the bundle path and calculate the MD5 hash of each file on disk
 	// at the moment
-	err := filepath.Walk(path, func(path string, info os.FileInfo, err error) error {
+	err := filepath.WalkDir(path, func(path string, entry os.DirEntry, err error) error {
 		if err != nil {
 			return err
 		}
 
-		if info.IsDir() || dataFileLoaderFilter(path, info, 0) {
+		if rio.IsSkipWalkDirectory(entry) {
+			return filepath.SkipDir
+		}
+
+		if entry.IsDir() || !slices.Contains(filter, entry.Name()) {
 			return nil
 		}