package util import ( "bytes" "fmt" "strings" "github.com/chrislusf/seaweedfs/weed/glog" // "github.com/klauspost/compress/zstd" ) var ( UnsupportedCompression = fmt.Errorf("unsupported compression") ) func MaybeGzipData(input []byte) []byte { if IsGzippedContent(input) { return input } gzipped, err := GzipData(input) if err != nil { return input } if len(gzipped)*10 > len(input)*9 { return input } return gzipped } func MaybeDecompressData(input []byte) []byte { uncompressed, err := DecompressData(input) if err != nil { if err != UnsupportedCompression { glog.Errorf("decompressed data: %v", err) } return input } return uncompressed } func GzipData(input []byte) ([]byte, error) { w := new(bytes.Buffer) _, err := GzipStream(w, bytes.NewReader(input)) if err != nil { return nil, err } return w.Bytes(), nil } func ungzipData(input []byte) ([]byte, error) { w := new(bytes.Buffer) _, err := GunzipStream(w, bytes.NewReader(input)) if err != nil { return nil, err } return w.Bytes(), nil } func DecompressData(input []byte) ([]byte, error) { if IsGzippedContent(input) { return ungzipData(input) } /* if IsZstdContent(input) { return unzstdData(input) } */ return input, UnsupportedCompression } func IsGzippedContent(data []byte) bool { if len(data) < 2 { return false } return data[0] == 31 && data[1] == 139 } /* var zstdEncoder, _ = zstd.NewWriter(nil) func ZstdData(input []byte) ([]byte, error) { return zstdEncoder.EncodeAll(input, nil), nil } var decoder, _ = zstd.NewReader(nil) func unzstdData(input []byte) ([]byte, error) { return decoder.DecodeAll(input, nil) } func IsZstdContent(data []byte) bool { if len(data) < 4 { return false } return data[3] == 0xFD && data[2] == 0x2F && data[1] == 0xB5 && data[0] == 0x28 } */ /* * Default not to compressed since compression can be done on client side. */func IsCompressableFileType(ext, mtype string) (shouldBeCompressed, iAmSure bool) { // text if strings.HasPrefix(mtype, "text/") { return true, true } // images switch ext { case ".svg", ".bmp", ".wav": return true, true } if strings.HasPrefix(mtype, "image/") { return false, true } // by file name extension switch ext { case ".zip", ".rar", ".gz", ".bz2", ".xz", ".zst", ".br": return false, true case ".pdf", ".txt", ".html", ".htm", ".css", ".js", ".json": return true, true case ".php", ".java", ".go", ".rb", ".c", ".cpp", ".h", ".hpp": return true, true case ".png", ".jpg", ".jpeg": return false, true } // by mime type if strings.HasPrefix(mtype, "application/") { if strings.HasSuffix(mtype, "zstd") { return false, true } if strings.HasSuffix(mtype, "xml") { return true, true } if strings.HasSuffix(mtype, "script") { return true, true } if strings.HasSuffix(mtype, "vnd.rar") { return false, true } } if strings.HasPrefix(mtype, "audio/") { switch strings.TrimPrefix(mtype, "audio/") { case "wave", "wav", "x-wav", "x-pn-wav": return true, true } } return false, false }