Simplify dirArchive by using os.dirFS and have Archive.Open return fs.File

internal/archive/archive.go

@@ -30,6 +30,7 @@ import (
 	"archive/zip"
 	"fmt"
 	"io"
+	"io/fs"
 	"os"
 	"path/filepath"
 )
@@ -37,7 +38,7 @@ import (
 // Generic archive interface.
 type Archive interface {
 	Close() error
-	OpenFile(path string) (io.ReadCloser, error)
+	Open(path string) (fs.File, error)
 	Glob(pattern string) ([]FileInfo, error)
 }
 
@@ -53,14 +54,14 @@ func OpenArchive(path string) (Archive, error) {
 	switch mode := fi.Mode(); {
 	case mode.IsRegular():
 		archive := &zipArchive{}
-		err := archive.Open(path)
+		err := archive.OpenArchive(path)
 		if err != nil {
 			return nil, err
 		}
 		return archive, nil
 	case mode.IsDir():
 		archive := &dirArchive{}
-		err := archive.Open(path)
+		err := archive.OpenArchive(path)
 		if err != nil {
 			return nil, err
 		}
@@ -95,7 +96,7 @@ type zipArchive struct {
 	zip *zip.ReadCloser
 }
 
-func (a *zipArchive) Open(path string) error {
+func (a *zipArchive) OpenArchive(path string) error {
 	zip, err := zip.OpenReader(path)
 	if err != nil {
 		return err
@@ -129,7 +130,7 @@ func (a *zipArchive) Glob(pattern string) ([]FileInfo, error) {
 	return result, nil
 }
 
-func (a *zipArchive) OpenFile(path string) (io.ReadCloser, error) {
+func (a *zipArchive) Open(path string) (fs.File, error) {
 	file, err := a.zip.Open(path)
 	if err != nil {
 		return nil, err
@@ -139,11 +140,13 @@ func (a *zipArchive) OpenFile(path string) (io.ReadCloser, error) {
 
 // An implementation of the archiveBackend interface for directories.
 type dirArchive struct {
-	dir string
+	path  string
+	dirFS fs.FS
 }
 
-func (a *dirArchive) Open(path string) error {
-	a.dir = filepath.Clean(path)
+func (a *dirArchive) OpenArchive(path string) error {
+	a.path = filepath.Clean(path)
+	a.dirFS = os.DirFS(path)
 	return nil
 }
 
@@ -151,28 +154,23 @@ func (a *dirArchive) Close() error {
 	return nil
 }
 
-func (a *dirArchive) OpenFile(path string) (io.ReadCloser, error) {
-	file, err := os.Open(filepath.Join(a.dir, path))
-	if err != nil {
-		return nil, err
-	}
-	return file, nil
+// Open opens the named file in the archive.
+// [fs.File.Close] must be called to release any associated resources.
+func (a *dirArchive) Open(path string) (fs.File, error) {
+	return a.dirFS.Open(path)
 }
 
 func (a *dirArchive) Glob(pattern string) ([]FileInfo, error) {
-	files, err := filepath.Glob(filepath.Join(a.dir, pattern))
+	files, err := fs.Glob(a.dirFS, pattern)
 	if err != nil {
 		return nil, err
 	}
 	result := make([]FileInfo, 0)
-	for _, filename := range files {
-		name, err := filepath.Rel(a.dir, filename)
-		if err != nil {
-			return nil, err
-		}
+	for _, name := range files {
+		fullPath := filepath.Join(a.path, name)
 		info := FileInfo{
 			Name: name,
-			File: &filesystemFile{path: filename},
+			File: &filesystemFile{path: fullPath},
 		}
 		result = append(result, info)
 	}

internal/listenbrainz/archive.go

@@ -63,7 +63,7 @@ func (a *ExportArchive) Close() error {
 
 // Read the user information from the archive.
 func (a *ExportArchive) UserInfo() (UserInfo, error) {
-	f, err := a.backend.OpenFile("user.json")
+	f, err := a.backend.Open("user.json")
 	if err != nil {
 		return UserInfo{}, err
 	}