github.com/vicanso/pike@v1.0.1-0.20210630235453-9099e041f6ec/compress/gzip.go (about)

     1  // MIT License
     2  
     3  // Copyright (c) 2020 Tree Xie
     4  
     5  // Permission is hereby granted, free of charge, to any person obtaining a copy
     6  // of this software and associated documentation files (the "Software"), to deal
     7  // in the Software without restriction, including without limitation the rights
     8  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     9  // copies of the Software, and to permit persons to whom the Software is
    10  // furnished to do so, subject to the following conditions:
    11  
    12  // The above copyright notice and this permission notice shall be included in all
    13  // copies or substantial portions of the Software.
    14  
    15  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    16  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    17  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    18  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    19  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    20  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    21  // SOFTWARE.
    22  
    23  package compress
    24  
    25  import (
    26  	"bytes"
    27  	"compress/gzip"
    28  	"io/ioutil"
    29  )
    30  
    31  // doGunzip gunzip
    32  func doGunzip(buf []byte) ([]byte, error) {
    33  	r, err := gzip.NewReader(bytes.NewBuffer(buf))
    34  	if err != nil {
    35  		return nil, err
    36  	}
    37  	defer r.Close()
    38  	return ioutil.ReadAll(r)
    39  }
    40  
    41  func gzipFn(buf []byte, level int) (*bytes.Buffer, error) {
    42  	buffer := new(bytes.Buffer)
    43  	if level <= 0 || level > gzip.BestCompression {
    44  		level = gzip.DefaultCompression
    45  	}
    46  	w, err := gzip.NewWriterLevel(buffer, level)
    47  	if err != nil {
    48  		return nil, err
    49  	}
    50  	defer w.Close()
    51  	_, err = w.Write(buf)
    52  	if err != nil {
    53  		return nil, err
    54  	}
    55  	return buffer, nil
    56  }
    57  
    58  // doGzip gzip function
    59  func doGzip(buf []byte, level int) ([]byte, error) {
    60  	buffer, err := gzipFn(buf, level)
    61  	if err != nil {
    62  		return nil, err
    63  	}
    64  	return buffer.Bytes(), nil
    65  }