mirror of
https://github.com/nabbar/golib.git
synced 2025-09-27 04:06:05 +08:00
cd083bb53f
- adding package to compress/uncompress with reader or writer - refactor to allowing to use same source of io as result: io.reader or io.writer - optimize code & buf to limit mem use - rework variable to be thread safe Package archive/compress - add function DetectOnly to detect algo and return an updated reader but not the decompressor reader - update function Detect to use DetectOnly to limit duplication code Other - bump dependencies
118 lines
2.5 KiB
Go
118 lines
2.5 KiB
Go
/*
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* MIT License
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*
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* Copyright (c) 2020 Nicolas JUHEL
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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package compress
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import "bytes"
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type Algorithm uint8
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const (
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None Algorithm = iota
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Bzip2
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Gzip
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LZ4
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XZ
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)
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func List() []Algorithm {
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return []Algorithm{
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None,
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Bzip2,
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Gzip,
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LZ4,
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XZ,
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}
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}
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func ListString() []string {
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var (
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lst = List()
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res = make([]string, len(lst))
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)
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for i := range lst {
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res[i] = lst[i].String()
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}
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return res
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}
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func (a Algorithm) IsNone() bool {
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return a == None
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}
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func (a Algorithm) String() string {
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switch a {
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case Gzip:
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return "gzip"
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case Bzip2:
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return "bzip2"
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case LZ4:
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return "lz4"
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case XZ:
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return "xz"
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default:
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return "none"
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}
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}
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func (a Algorithm) Extension() string {
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switch a {
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case Gzip:
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return ".gz"
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case Bzip2:
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return ".bz2"
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case LZ4:
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return ".lz4"
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case XZ:
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return ".xz"
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default:
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return ""
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}
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}
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func (a Algorithm) DetectHeader(h []byte) bool {
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if len(h) < 6 {
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return false
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}
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switch a {
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case Gzip:
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exp := []byte{31, 139}
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return bytes.Equal(h[0:2], exp)
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case Bzip2:
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exp := []byte{'B', 'Z', 'h'}
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return bytes.Equal(h[0:3], exp) && h[3] >= '0' && h[3] <= '9'
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case LZ4:
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exp := []byte{0x04, 0x22, 0x4D, 0x18}
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return bytes.Equal(h[0:4], exp)
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case XZ:
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exp := []byte{0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00}
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alt := []byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}
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return bytes.Equal(h[0:6], exp) || bytes.Equal(h[0:6], alt)
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default:
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return false
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}
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}
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