/
compress.go
82 lines (66 loc) · 2.22 KB
/
compress.go
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/*
* Copyright (c) 2017 AlexRuzin (stan.ruzin@gmail.com)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package util
import (
"bytes"
"io/ioutil"
"errors"
/* Preference for the gunzip compressor, although using zlib follows the same I/O API */
"compress/gzip"
_"compress/zlib"
)
/* Use gzip compression to generate a compressed stream */
func CompressStream(p []byte) ([]byte, error) {
var in bytes.Buffer
gz := gzip.NewWriter(&in)
defer gz.Close()
if _, err := gz.Write(p); err != nil {
return nil, err
}
gz.Flush()
return in.Bytes(), nil
}
/* Decompression subroutine */
func DecompressStream(p []byte) ([]byte, error) {
in := bytes.NewReader(p)
gz, err := gzip.NewReader(in)
if err != nil {
return nil, err
}
defer gz.Close()
decompressed, _ := ioutil.ReadAll(gz)
if len(decompressed) == 0 {
return nil, errors.New("decompressed stream is 0 bytes")
}
return decompressed, nil
}
func GetCompressedSize(p []byte) int {
var (
err error = nil
compressed []byte
)
compressed, err = CompressStream(p)
if err != nil {
panic(err)
}
return len(compressed)
}