138 lines
3 KiB
Go
138 lines
3 KiB
Go
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package archiver
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import "bytes"
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import "compress/gzip"
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import "fmt"
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import "github.com/foobaz/go-zopfli/zopfli"
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import "github.com/andybalholm/brotli"
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func Compress (_data []byte, _algorithm string, _level int) ([]byte, error) {
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switch _algorithm {
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case "gz", "gzip" :
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return CompressGzip (_data, _level)
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case "zopfli" :
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return CompressZopfli (_data, _level)
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case "br", "brotli" :
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return CompressBrotli (_data, _level)
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case "", "none", "identity" :
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return _data, nil
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default :
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return nil, fmt.Errorf ("[ea23f966] invalid compression algorithm `%s`", _algorithm)
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}
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}
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func CompressEncoding (_algorithm string) (string, string, error) {
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switch _algorithm {
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case "gz", "gzip" :
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return "gzip", "gzip", nil
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case "zopfli" :
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return "zopfli", "gzip", nil
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case "br", "brotli" :
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return "brotli", "br", nil
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case "", "none", "identity" :
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return "identity", "identity", nil
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default :
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return "", "", fmt.Errorf ("[6026a403] invalid compression algorithm `%s`", _algorithm)
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}
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}
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func CompressGzip (_data []byte, _level int) ([]byte, error) {
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_buffer := & bytes.Buffer {}
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if (_level < -2) || (_level > 9) {
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return nil, fmt.Errorf ("[a6c02c58] invalid compression level `%d` (-1 for default, -2 for Huffman only, 0 to 9 for fast to slow)", _level)
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}
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var _encoder *gzip.Writer
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if _encoder_0, _error := gzip.NewWriterLevel (_buffer, _level); _error == nil {
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_encoder = _encoder_0
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} else {
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return nil, _error
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}
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if _, _error := _encoder.Write (_data); _error != nil {
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return nil, _error
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}
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if _error := _encoder.Close (); _error != nil {
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return nil, _error
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}
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_data = _buffer.Bytes ()
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return _data, nil
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}
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func CompressZopfli (_data []byte, _level int) ([]byte, error) {
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if (_level < -1) || (_level > 30) {
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return nil, fmt.Errorf ("[fe30ea07] invalid compression level `%d` (-1 for default, 0 to 30 iterations for fast to slow)", _level)
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}
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_buffer := & bytes.Buffer {}
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_options := zopfli.DefaultOptions ()
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if _level != -1 {
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_options.NumIterations = _level
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_options.BlockSplitting = true
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_options.BlockSplittingLast = false
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_options.BlockSplittingMax = 0
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_options.BlockType = zopfli.DYNAMIC_BLOCK
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}
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if _error := zopfli.GzipCompress (&_options, _data, _buffer); _error != nil {
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return nil, _error
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}
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_data = _buffer.Bytes ()
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return _data, nil
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}
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func CompressBrotli (_data []byte, _level int) ([]byte, error) {
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if (_level < -2) || (_level > 9) {
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return nil, fmt.Errorf ("[4aa20d1b] invalid compression level `%d` (-1 for default, 0 to 9 for fast to slow, -2 for extreme)", _level)
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}
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_buffer := & bytes.Buffer {}
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_options := brotli.WriterOptions {}
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if _level == -2 {
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_options.Quality = 11
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_options.LGWin = 24
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} else if _level == -1 {
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_options.Quality = 6
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} else {
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_options.Quality = _level
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}
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_encoder := brotli.NewWriterOptions (_buffer, _options)
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if _, _error := _encoder.Write (_data); _error != nil {
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return nil, _error
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}
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if _error := _encoder.Close (); _error != nil {
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return nil, _error
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}
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_data = _buffer.Bytes ()
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return _data, nil
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}
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