mirror of https://github.com/go-gitea/gitea.git
125 lines
3.7 KiB
Go
125 lines
3.7 KiB
Go
/*
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* XZ decompressor
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*
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* Authors: Lasse Collin <lasse.collin@tukaani.org>
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* Igor Pavlov <http://7-zip.org/>
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*
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* Translation to Go: Michael Cross <https://github.com/xi2>
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*
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* This file has been put into the public domain.
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* You can do whatever you want with this file.
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*/
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package xz
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/* from linux/include/linux/xz.h **************************************/
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/**
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* xzRet - Return codes
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* @xzOK: Everything is OK so far. More input or more
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* output space is required to continue.
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* @xzStreamEnd: Operation finished successfully.
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* @xzUnSupportedCheck: Integrity check type is not supported. Decoding
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* is still possible by simply calling xzDecRun
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* again.
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* @xzMemlimitError: A bigger LZMA2 dictionary would be needed than
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* allowed by the dictMax argument given to
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* xzDecInit.
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* @xzFormatError: File format was not recognized (wrong magic
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* bytes).
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* @xzOptionsError: This implementation doesn't support the requested
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* compression options. In the decoder this means
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* that the header CRC32 matches, but the header
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* itself specifies something that we don't support.
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* @xzDataError: Compressed data is corrupt.
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* @xzBufError: Cannot make any progress.
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*
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* xzBufError is returned when two consecutive calls to XZ code cannot
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* consume any input and cannot produce any new output. This happens
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* when there is no new input available, or the output buffer is full
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* while at least one output byte is still pending. Assuming your code
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* is not buggy, you can get this error only when decoding a
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* compressed stream that is truncated or otherwise corrupt.
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*/
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type xzRet int
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const (
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xzOK xzRet = iota
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xzStreamEnd
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xzUnsupportedCheck
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xzMemlimitError
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xzFormatError
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xzOptionsError
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xzDataError
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xzBufError
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)
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/**
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* xzBuf - Passing input and output buffers to XZ code
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* @in: Input buffer.
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* @inPos: Current position in the input buffer. This must not exceed
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* input buffer size.
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* @out: Output buffer.
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* @outPos: Current position in the output buffer. This must not exceed
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* output buffer size.
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*
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* Only the contents of the output buffer from out[outPos] onward, and
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* the variables inPos and outPos are modified by the XZ code.
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*/
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type xzBuf struct {
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in []byte
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inPos int
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out []byte
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outPos int
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}
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/* All XZ filter IDs */
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type xzFilterID int64
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const (
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idDelta xzFilterID = 0x03
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idBCJX86 xzFilterID = 0x04
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idBCJPowerPC xzFilterID = 0x05
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idBCJIA64 xzFilterID = 0x06
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idBCJARM xzFilterID = 0x07
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idBCJARMThumb xzFilterID = 0x08
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idBCJSPARC xzFilterID = 0x09
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idLZMA2 xzFilterID = 0x21
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)
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// CheckID is the type of the data integrity check in an XZ stream
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// calculated from the uncompressed data.
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type CheckID int
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func (id CheckID) String() string {
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switch id {
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case CheckNone:
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return "None"
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case CheckCRC32:
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return "CRC32"
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case CheckCRC64:
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return "CRC64"
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case CheckSHA256:
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return "SHA256"
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default:
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return "Unknown"
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}
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}
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const (
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CheckNone CheckID = 0x00
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CheckCRC32 CheckID = 0x01
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CheckCRC64 CheckID = 0x04
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CheckSHA256 CheckID = 0x0A
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checkMax CheckID = 0x0F
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checkUnset CheckID = -1
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)
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// An XZ stream contains a stream header which holds information about
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// the stream. That information is exposed as fields of the
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// Reader. Currently it contains only the stream's data integrity
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// check type.
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type Header struct {
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CheckType CheckID // type of the stream's data integrity check
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}
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