github.com/bhojpur/cache@v0.0.4/pkg/file/core/compress.go (about)

     1  package core
     2  
     3  // Copyright (c) 2018 Bhojpur Consulting Private Limited, India. All rights reserved.
     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
    13  // all 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
    21  // THE SOFTWARE.
    22  
    23  import (
    24  	"bytes"
    25  	"compress/flate"
    26  	"io"
    27  )
    28  
    29  // CompressBytes returns a compressed byte slice.
    30  func CompressBytes(src []byte) []byte {
    31  	compressedData := new(bytes.Buffer)
    32  	compress(src, compressedData, -2)
    33  	return compressedData.Bytes()
    34  }
    35  
    36  // DecompressBytes returns a decompressed byte slice.
    37  func DecompressBytes(src []byte) []byte {
    38  	compressedData := bytes.NewBuffer(src)
    39  	deCompressedData := new(bytes.Buffer)
    40  	decompress(compressedData, deCompressedData)
    41  	return deCompressedData.Bytes()
    42  }
    43  
    44  // compress uses flate to compress a byte slice to a corresponding level.
    45  func compress(src []byte, dest io.Writer, level int) {
    46  	compressor, _ := flate.NewWriter(dest, level)
    47  	compressor.Write(src)
    48  	compressor.Close()
    49  }
    50  
    51  // compress uses flate to decompress an io.Reader.
    52  func decompress(src io.Reader, dest io.Writer) {
    53  	decompressor := flate.NewReader(src)
    54  	io.Copy(dest, decompressor)
    55  	decompressor.Close()
    56  }