forked from ortuman/jackal
/
zlib.go
63 lines (57 loc) · 1.15 KB
/
zlib.go
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/*
* Copyright (c) 2018 Miguel Ángel Ortuño.
* See the LICENSE file for more information.
*/
package compress
import (
"compress/zlib"
"io"
)
// ZlibCompressor represents zlib stream compressor.
type ZlibCompressor struct {
level int
w io.Writer
r io.Reader
zw io.Writer
zr io.Reader
}
// NewZlibCompressor returns a new zlib compression method.
func NewZlibCompressor(reader io.Reader, writer io.Writer, level Level) *ZlibCompressor {
z := &ZlibCompressor{
w: writer,
r: reader,
}
switch level {
case DefaultCompression:
z.level = zlib.DefaultCompression
case BestCompression:
z.level = zlib.BestCompression
case SpeedCompression:
z.level = zlib.BestSpeed
default:
z.level = int(level)
}
return z
}
func (z *ZlibCompressor) Write(p []byte) (int, error) {
if z.zw == nil {
zw, err := zlib.NewWriterLevel(z.w, z.level)
if err != nil {
return 0, err
}
z.zw = zw
}
zw := z.zw.(*zlib.Writer)
defer zw.Flush()
return zw.Write(p)
}
func (z *ZlibCompressor) Read(p []byte) (int, error) {
if z.zr == nil {
zr, err := zlib.NewReader(z.r)
if err != nil {
return 0, err
}
z.zr = zr
}
return z.zr.Read(p)
}