/
compressors.go
90 lines (80 loc) · 2 KB
/
compressors.go
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package encryptedbox
import (
"bytes"
"compress/gzip"
"compress/zlib"
"fmt"
"io"
)
var (
Zlib Compressor = ZlibCompression(zlib.BestCompression)
Gzip Compressor = GzipCompression(gzip.BestCompression)
)
func GzipCompression(level int) Compressor {
return gzipCompressor{level}
}
func ZlibCompression(level int) Compressor {
return zlibCompressor{level}
}
type gzipCompressor struct {
level int
}
func (z gzipCompressor) Compress(data []byte) ([]byte, error) {
b := bytes.Buffer{}
w, err := gzip.NewWriterLevel(&b, z.level)
if err != nil {
return nil, fmt.Errorf("failed to init gzip: %w", err)
}
_, err = w.Write(data)
err2 := w.Close()
if err != nil {
return nil, fmt.Errorf("compression failed: %w", err)
} else if err2 != nil {
return nil, fmt.Errorf("compression failed: %w", err2)
}
return b.Bytes(), nil
}
func (z gzipCompressor) Decompress(data []byte) ([]byte, error) {
r, err := gzip.NewReader(bytes.NewBuffer(data))
if err != nil {
return nil, fmt.Errorf("decompression failed: %w", err)
}
defer r.Close()
out := bytes.Buffer{}
_, err = io.Copy(&out, r)
if err != nil {
return nil, fmt.Errorf("decompression failed: %w", err)
}
return out.Bytes(), nil
}
type zlibCompressor struct {
level int
}
func (z zlibCompressor) Compress(data []byte) ([]byte, error) {
b := bytes.Buffer{}
w, err := zlib.NewWriterLevel(&b, z.level)
if err != nil {
return nil, fmt.Errorf("failed to init zlib: %w", err)
}
_, err = w.Write(data)
err2 := w.Close()
if err != nil {
return nil, fmt.Errorf("compression failed: %w", err)
} else if err2 != nil {
return nil, fmt.Errorf("compression failed: %w", err2)
}
return b.Bytes(), nil
}
func (z zlibCompressor) Decompress(data []byte) ([]byte, error) {
r, err := zlib.NewReader(bytes.NewBuffer(data))
if err != nil {
return nil, fmt.Errorf("decompression failed: %w", err)
}
defer r.Close()
out := bytes.Buffer{}
_, err = io.Copy(&out, r)
if err != nil {
return nil, fmt.Errorf("decompression failed: %w", err)
}
return out.Bytes(), nil
}