Method newCompressedFSFileCache

fs.go:1767–1835

newCompressedFSFileCache use memory cache compressed files.

(f fs.File, fileInfo fs.FileInfo, filePath, fileEncoding string)

// newCompressedFSFileCache use memory cache compressed files.
func (h *fsHandler) newCompressedFSFileCache(f fs.File, fileInfo fs.FileInfo, filePath, fileEncoding string) (*fsFile, error) {
	var (
		w   = &bytebufferpool.ByteBuffer{}
		err error
	)

	switch fileEncoding {
	case "br":
		zw := acquireStacklessBrotliWriter(w, CompressDefaultCompression)
		_, err = copyZeroAlloc(zw, f)
		if errf := zw.Flush(); err == nil {
			err = errf
		}
		releaseStacklessBrotliWriter(zw, CompressDefaultCompression)
	case "gzip":
		zw := acquireStacklessGzipWriter(w, CompressDefaultCompression)
		_, err = copyZeroAlloc(zw, f)
		if errf := zw.Flush(); err == nil {
			err = errf
		}
		releaseStacklessGzipWriter(zw, CompressDefaultCompression)
	case "zstd":
		zw := acquireStacklessZstdWriter(w, CompressZstdDefault)
		_, err = copyZeroAlloc(zw, f)
		if errf := zw.Flush(); err == nil {
			err = errf
		}
		releaseStacklessZstdWriter(zw, CompressZstdDefault)
	}
	defer func() { _ = f.Close() }()

	if err != nil {
		return nil, fmt.Errorf("error when compressing file %q: %w", filePath, err)
	}

	seeker, ok := f.(io.Seeker)
	if !ok {
		return nil, errors.New("not implemented io.Seeker")
	}
	if _, err = seeker.Seek(0, io.SeekStart); err != nil {
		return nil, err
	}

	ext := fileExtension(fileInfo.Name(), false, h.compressedFileSuffixes[fileEncoding])
	contentType := mime.TypeByExtension(ext)
	if contentType == "" {
		data, err := readFileHeader(f, false, fileEncoding)
		if err != nil {
			return nil, fmt.Errorf("cannot read header of the file %q: %w", fileInfo.Name(), err)
		}
		contentType = http.DetectContentType(data)
	}

	dirIndex := w.B
	lastModified := fileInfo.ModTime()
	ff := &fsFile{
		h:               h,
		dirIndex:        dirIndex,