From 1029cc8f0f70d9173d76d6039b98083b3b94f0d5 Mon Sep 17 00:00:00 2001
From: William Petit <wpetit@cadoles.com>
Date: Thu, 2 May 2024 09:43:22 +0200
Subject: [PATCH] feat: load zip bundle from io.ReaderAt

---
 pkg/bundle/bundle_test.go |  2 +-
 pkg/bundle/from_path.go   |  2 +-
 pkg/bundle/zip_bundle.go  | 58 ++++++++++++++++++++-------------------
 3 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/pkg/bundle/bundle_test.go b/pkg/bundle/bundle_test.go
index 694e6b3..1dad14a 100644
--- a/pkg/bundle/bundle_test.go
+++ b/pkg/bundle/bundle_test.go
@@ -16,7 +16,7 @@ func TestBundle(t *testing.T) {
 	bundles := []Bundle{
 		NewDirectoryBundle("testdata/bundle"),
 		NewTarBundle("testdata/bundle.tar.gz"),
-		NewZipBundle("testdata/bundle.zip"),
+		Must(NewZipBundleFromPath("testdata/bundle.zip")),
 	}
 
 	for _, b := range bundles {
diff --git a/pkg/bundle/from_path.go b/pkg/bundle/from_path.go
index 2b2f6ed..0532c00 100644
--- a/pkg/bundle/from_path.go
+++ b/pkg/bundle/from_path.go
@@ -54,7 +54,7 @@ func matchArchivePattern(archivePath string) (Bundle, error) {
 	}
 
 	if matches {
-		return NewZipBundle(archivePath), nil
+		return NewZipBundleFromPath(archivePath)
 	}
 
 	matches, err = filepath.Match(fmt.Sprintf("*.%s", ExtZim), base)
diff --git a/pkg/bundle/zip_bundle.go b/pkg/bundle/zip_bundle.go
index 76d8ea0..3553683 100644
--- a/pkg/bundle/zip_bundle.go
+++ b/pkg/bundle/zip_bundle.go
@@ -13,15 +13,10 @@ import (
 )
 
 type ZipBundle struct {
-	archivePath string
+	reader *zip.Reader
 }
 
 func (b *ZipBundle) File(filename string) (io.ReadCloser, os.FileInfo, error) {
-	reader, err := b.openArchive()
-	if err != nil {
-		return nil, nil, err
-	}
-
 	ctx := logger.With(
 		context.Background(),
 		logger.F("filename", filename),
@@ -29,7 +24,7 @@ func (b *ZipBundle) File(filename string) (io.ReadCloser, os.FileInfo, error) {
 
 	logger.Debug(ctx, "opening file")
 
-	f, err := reader.Open(filename)
+	f, err := b.reader.Open(filename)
 	if err != nil {
 		return nil, nil, errors.WithStack(err)
 	}
@@ -43,21 +38,10 @@ func (b *ZipBundle) File(filename string) (io.ReadCloser, os.FileInfo, error) {
 }
 
 func (b *ZipBundle) Dir(dirname string) ([]os.FileInfo, error) {
-	reader, err := b.openArchive()
-	if err != nil {
-		return nil, err
-	}
-
-	defer func() {
-		if err := reader.Close(); err != nil {
-			panic(errors.WithStack(err))
-		}
-	}()
-
 	files := make([]os.FileInfo, 0)
 	ctx := context.Background()
 
-	for _, f := range reader.File {
+	for _, f := range b.reader.File {
 		if !strings.HasPrefix(f.Name, dirname) {
 			continue
 		}
@@ -82,17 +66,35 @@ func (b *ZipBundle) Dir(dirname string) ([]os.FileInfo, error) {
 	return files, nil
 }
 
-func (b *ZipBundle) openArchive() (*zip.ReadCloser, error) {
-	zr, err := zip.OpenReader(b.archivePath)
+func NewZipBundleFromReader(reader io.ReaderAt, size int64) (*ZipBundle, error) {
+	zipReader, err := zip.NewReader(reader, size)
 	if err != nil {
-		return nil, errors.Wrapf(err, "could not decompress '%v'", b.archivePath)
+		return nil, errors.WithStack(err)
 	}
 
-	return zr, nil
-}
-
-func NewZipBundle(archivePath string) *ZipBundle {
 	return &ZipBundle{
-		archivePath: archivePath,
-	}
+		reader: zipReader,
+	}, nil
+}
+
+func NewZipBundleFromPath(filename string) (*ZipBundle, error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	stat, err := file.Stat()
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return NewZipBundleFromReader(file, stat.Size())
+}
+
+func Must(bundle Bundle, err error) Bundle {
+	if err != nil {
+		panic(errors.WithStack(err))
+	}
+
+	return bundle
 }