79 lines
4.6 KiB
C
79 lines
4.6 KiB
C
#ifndef COSMOPOLITAN_LIBC_LZ4_H_
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#define COSMOPOLITAN_LIBC_LZ4_H_
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#include "libc/bits/bits.h"
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#if 0
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/*───────────────────────────────────────────────────────────────────────────│─╗
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│ cosmopolitan § lz4 ─╬─│┼
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╚────────────────────────────────────────────────────────────────────────────│─╝
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LZ4 is a framing format for REP MOVSB designed by Yann Collet.
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@see https://github.com/lz4/lz4/blob/master/doc/lz4_Frame_format.md
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@see https://github.com/lz4/lz4/blob/master/doc/lz4_Block_format.md
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@see http://ticki.github.io/blog/how-lz4-works/ */
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#endif
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#define LZ4_EOF 0
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#define LZ4_VERSION 1
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#define LZ4_MAGICNUMBER 0x184D2204
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#define LZ4_SKIPPABLE0 0x184D2A50
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#define LZ4_SKIPPABLEMASK 0xFFFFFFF0
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#define LZ4_MAXHEADERSIZE (MAGICNUMBER_SIZE + 2 + 8 + 4 + 1)
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#define LZ4_BLOCKMAXSIZE_64KB 4
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#define LZ4_BLOCKMAXSIZE_256KB 5
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#define LZ4_BLOCKMAXSIZE_1MB 6
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#define LZ4_BLOCKMAXSIZE_4MB 7
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#if !(__ASSEMBLER__ + __LINKER__ + 0)
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COSMOPOLITAN_C_START_
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#if 0
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/*───────────────────────────────────────────────────────────────────────────│─╗
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│ cosmopolitan § lz4 » frames ─╬─│┼
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╚────────────────────────────────────────────────────────────────────────────│*/
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#endif
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#define LZ4_MAGIC(FRAME) read32le(FRAME)
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#define LZ4_FRAME_VERSION(FRAME) ((_LZ4_FRAME_FLG(FRAME) >> 6) & 0b11)
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#define LZ4_FRAME_BLOCKINDEPENDENCE(FRAME) ((_LZ4_FRAME_FLG(FRAME) >> 5) & 1)
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#define LZ4_FRAME_BLOCKCHECKSUMFLAG(FRAME) ((_LZ4_FRAME_FLG(FRAME) >> 4) & 1)
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#define LZ4_FRAME_BLOCKCONTENTSIZEFLAG(FRAME) ((_LZ4_FRAME_FLG(FRAME) >> 3) & 1)
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#define LZ4_FRAME_BLOCKCONTENTCHECKSUMFLAG(FRAME) \
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((_LZ4_FRAME_FLG(FRAME) >> 2) & 1)
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#define LZ4_FRAME_DICTIONARYIDFLAG(FRAME) ((_LZ4_FRAME_FLG(FRAME) >> 0) & 1)
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#define LZ4_FRAME_BLOCKMAXSIZE(FRAME) ((_LZ4_FRAME_BD(FRAME) >> 4) & 0b111)
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#define LZ4_FRAME_RESERVED1(FRAME) ((_LZ4_FRAME_FLG(FRAME) >> 1) & 1)
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#define LZ4_FRAME_RESERVED2(FRAME) ((_LZ4_FRAME_BD(FRAME) >> 7) & 1)
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#define LZ4_FRAME_RESERVED3(FRAME) ((_LZ4_FRAME_BD(FRAME) >> 0) & 0b1111)
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#define LZ4_FRAME_BLOCKCONTENTSIZE(FRAME) \
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(LZ4_FRAME_BLOCKCONTENTSIZEFLAG(FRAME) ? read64le((FRAME) + 4 + 1 + 1) : 0)
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#define LZ4_FRAME_DICTIONARYID(FRAME) \
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(LZ4_FRAME_DICTIONARYIDFLAG(FRAME) \
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? read32le(((FRAME) + 4 + 1 + 1 + \
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8 * LZ4_FRAME_BLOCKCONTENTSIZEFLAG(FRAME))) \
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: 0)
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#define LZ4_FRAME_HEADERCHECKSUM(FRAME) \
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(*((FRAME) + 4 + 1 + 1 + 8 * LZ4_FRAME_BLOCKCONTENTSIZEFLAG(FRAME) + \
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4 * LZ4_FRAME_DICTIONARYIDFLAG(FRAME)))
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#define LZ4_FRAME_HEADERSIZE(FRAME) \
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(4 + 1 + 1 + 8 * LZ4_FRAME_BLOCKCONTENTSIZEFLAG(FRAME) + \
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4 * LZ4_FRAME_DICTIONARYIDFLAG(FRAME) + 1)
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#define _LZ4_FRAME_FLG(FRAME) (*((FRAME) + 4))
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#define _LZ4_FRAME_BD(FRAME) (*((FRAME) + 5))
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#if 0
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/*───────────────────────────────────────────────────────────────────────────│─╗
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│ cosmopolitan § lz4 » blocks ─╬─│┼
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╚────────────────────────────────────────────────────────────────────────────│*/
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#endif
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#define LZ4_BLOCK_DATA(block) (block + sizeof(uint32_t))
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#define LZ4_BLOCK_DATASIZE(block) (read32le(block) & 0x7fffffff)
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#define LZ4_BLOCK_ISEOF(block) (read32le(block) == LZ4_EOF)
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#define LZ4_BLOCK_ISCOMPRESSED(block) ((read32le(block) & 0x80000000) == 0)
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#define LZ4_BLOCK_SIZE(frame, block) \
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(sizeof(uint32_t) + LZ4_BLOCK_DATASIZE(block) + \
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(LZ4_FRAME_BLOCKCHECKSUMFLAG(frame) ? sizeof(uint8_t) : 0))
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COSMOPOLITAN_C_END_
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#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
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#endif /* COSMOPOLITAN_LIBC_LZ4_H_ */
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