| 1 |
package storage |
| 2 |
|
| 3 |
import ( |
| 4 |
"bytes" |
| 5 |
"fmt" |
| 6 |
"io" |
| 7 |
"sync" |
| 8 |
|
| 9 |
"github.com/klauspost/compress/zstd" |
| 10 |
) |
| 11 |
|
| 12 |
/* zstd compression wrapper for larc blob storage. |
| 13 |
* Uses encoder/decoder pools for efficiency. |
| 14 |
* Default compression level balances speed and ratio. */ |
| 15 |
|
| 16 |
const ( |
| 17 |
// DefaultCompressionLevel is the default zstd level (3 = fast, good ratio) |
| 18 |
DefaultCompressionLevel = 3 |
| 19 |
) |
| 20 |
|
| 21 |
var ( |
| 22 |
encoderPool sync.Pool |
| 23 |
decoderPool sync.Pool |
| 24 |
initOnce sync.Once |
| 25 |
) |
| 26 |
|
| 27 |
func initPools() { |
| 28 |
initOnce.Do(func() { |
| 29 |
encoderPool = sync.Pool{ |
| 30 |
New: func() any { |
| 31 |
enc, err := zstd.NewWriter(nil, |
| 32 |
zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(DefaultCompressionLevel)), |
| 33 |
zstd.WithEncoderConcurrency(1), |
| 34 |
) |
| 35 |
if err != nil { |
| 36 |
panic(fmt.Sprintf("failed to create zstd encoder: %v", err)) |
| 37 |
} |
| 38 |
return enc |
| 39 |
}, |
| 40 |
} |
| 41 |
|
| 42 |
decoderPool = sync.Pool{ |
| 43 |
New: func() any { |
| 44 |
dec, err := zstd.NewReader(nil, |
| 45 |
zstd.WithDecoderConcurrency(1), |
| 46 |
) |
| 47 |
if err != nil { |
| 48 |
panic(fmt.Sprintf("failed to create zstd decoder: %v", err)) |
| 49 |
} |
| 50 |
return dec |
| 51 |
}, |
| 52 |
} |
| 53 |
}) |
| 54 |
} |
| 55 |
|
| 56 |
// Compress compresses data using zstd |
| 57 |
func Compress(data []byte) ([]byte, error) { |
| 58 |
initPools() |
| 59 |
|
| 60 |
enc := encoderPool.Get().(*zstd.Encoder) |
| 61 |
defer encoderPool.Put(enc) |
| 62 |
|
| 63 |
var buf bytes.Buffer |
| 64 |
enc.Reset(&buf) |
| 65 |
|
| 66 |
if _, err := enc.Write(data); err != nil { |
| 67 |
return nil, fmt.Errorf("zstd compress write: %w", err) |
| 68 |
} |
| 69 |
|
| 70 |
if err := enc.Close(); err != nil { |
| 71 |
return nil, fmt.Errorf("zstd compress close: %w", err) |
| 72 |
} |
| 73 |
|
| 74 |
return buf.Bytes(), nil |
| 75 |
} |
| 76 |
|
| 77 |
// Decompress decompresses zstd data |
| 78 |
func Decompress(data []byte) ([]byte, error) { |
| 79 |
initPools() |
| 80 |
|
| 81 |
dec := decoderPool.Get().(*zstd.Decoder) |
| 82 |
defer decoderPool.Put(dec) |
| 83 |
|
| 84 |
if err := dec.Reset(bytes.NewReader(data)); err != nil { |
| 85 |
return nil, fmt.Errorf("zstd decompress reset: %w", err) |
| 86 |
} |
| 87 |
|
| 88 |
result, err := io.ReadAll(dec) |
| 89 |
if err != nil { |
| 90 |
return nil, fmt.Errorf("zstd decompress read: %w", err) |
| 91 |
} |
| 92 |
|
| 93 |
return result, nil |
| 94 |
} |
| 95 |
|
| 96 |
// CompressReader compresses from reader to writer |
| 97 |
func CompressReader(r io.Reader, w io.Writer) (int64, error) { |
| 98 |
initPools() |
| 99 |
|
| 100 |
enc := encoderPool.Get().(*zstd.Encoder) |
| 101 |
defer encoderPool.Put(enc) |
| 102 |
|
| 103 |
enc.Reset(w) |
| 104 |
|
| 105 |
n, err := io.Copy(enc, r) |
| 106 |
if err != nil { |
| 107 |
return n, fmt.Errorf("zstd compress copy: %w", err) |
| 108 |
} |
| 109 |
|
| 110 |
if err := enc.Close(); err != nil { |
| 111 |
return n, fmt.Errorf("zstd compress close: %w", err) |
| 112 |
} |
| 113 |
|
| 114 |
return n, nil |
| 115 |
} |
| 116 |
|
| 117 |
// DecompressReader decompresses from reader to writer |
| 118 |
func DecompressReader(r io.Reader, w io.Writer) (int64, error) { |
| 119 |
initPools() |
| 120 |
|
| 121 |
dec := decoderPool.Get().(*zstd.Decoder) |
| 122 |
defer decoderPool.Put(dec) |
| 123 |
|
| 124 |
if err := dec.Reset(r); err != nil { |
| 125 |
return 0, fmt.Errorf("zstd decompress reset: %w", err) |
| 126 |
} |
| 127 |
|
| 128 |
n, err := io.Copy(w, dec) |
| 129 |
if err != nil { |
| 130 |
return n, fmt.Errorf("zstd decompress copy: %w", err) |
| 131 |
} |
| 132 |
|
| 133 |
return n, nil |
| 134 |
} |
| 135 |
|
| 136 |
// CompressLevel compresses with specific compression level (1-19) |
| 137 |
func CompressLevel(data []byte, level int) ([]byte, error) { |
| 138 |
enc, err := zstd.NewWriter(nil, |
| 139 |
zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(level)), |
| 140 |
) |
| 141 |
if err != nil { |
| 142 |
return nil, fmt.Errorf("zstd new encoder: %w", err) |
| 143 |
} |
| 144 |
defer enc.Close() |
| 145 |
|
| 146 |
var buf bytes.Buffer |
| 147 |
enc.Reset(&buf) |
| 148 |
|
| 149 |
if _, err := enc.Write(data); err != nil { |
| 150 |
return nil, fmt.Errorf("zstd compress write: %w", err) |
| 151 |
} |
| 152 |
|
| 153 |
if err := enc.Close(); err != nil { |
| 154 |
return nil, fmt.Errorf("zstd compress close: %w", err) |
| 155 |
} |
| 156 |
|
| 157 |
return buf.Bytes(), nil |
| 158 |
} |
| 159 |
|