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/* LzmaDec.h -- LZMA Decoder↩
2018-04-21 : Igor Pavlov : Public domain */↩
↩
#ifndef __LZMA_DEC_H↩
#define __LZMA_DEC_H↩
↩
#include "7zTypes.h"↩
↩
EXTERN_C_BEGIN↩
↩
/* #define _LZMA_PROB32 */↩
/* _LZMA_PROB32 can increase the speed on some CPUs,↩
but memory usage for CLzmaDec::probs will be doubled in that case */↩
↩
typedef↩
#ifdef _LZMA_PROB32↩
UInt32↩
#else↩
UInt16↩
#endif↩
CLzmaProb;↩
↩
↩
/* ---------- LZMA Properties ---------- */↩
↩
#define LZMA_PROPS_SIZE 5↩
↩
typedef struct _CLzmaProps↩
{↩
Byte lc;↩
Byte lp;↩
Byte pb;↩
Byte _pad_;↩
UInt32 dicSize;↩
} CLzmaProps;↩
↩
/* LzmaProps_Decode - decodes properties↩
Returns:↩
SZ_OK↩
SZ_ERROR_UNSUPPORTED - Unsupported properties↩
*/↩
↩
SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size);↩
↩
↩
/* ---------- LZMA Decoder state ---------- */↩
↩
/* LZMA_REQUIRED_INPUT_MAX = number of required input bytes for worst case.↩
Num bits = log2((2^11 / 31) ^ 22) + 26 < 134 + 26 = 160; */↩
↩
#define LZMA_REQUIRED_INPUT_MAX 20↩
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typedef struct↩
{↩
/* Don't change this structure. ASM code can use it. */↩
CLzmaProps prop;↩
CLzmaProb *probs;↩
CLzmaProb *probs_1664;↩
Byte *dic;↩
SizeT dicBufSize;↩
SizeT dicPos;↩
const Byte *buf;↩
UInt32 range;↩
UInt32 code;↩
UInt32 processedPos;↩
UInt32 checkDicSize;↩
UInt32 reps[4];↩
UInt32 state;↩
UInt32 remainLen;↩
↩
UInt32 numProbs;↩
unsigned tempBufSize;↩
Byte tempBuf[LZMA_REQUIRED_INPUT_MAX];↩
} CLzmaDec;↩
↩
#define LzmaDec_Construct(p) { (p)->dic = NULL; (p)->probs = NULL; }↩
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void LzmaDec_Init(CLzmaDec *p);↩
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/* There are two types of LZMA streams:↩
- Stream with end mark. That end mark adds about 6 bytes to compressed size.↩
- Stream without end mark. You must know exact uncompressed size to decompress such stream. */↩
↩
typedef enum↩
{↩
LZMA_FINISH_ANY, /* finish at any point */↩
LZMA_FINISH_END /* block must be finished at the end */↩
} ELzmaFinishMode;↩
↩
/* ELzmaFinishMode has meaning only if the decoding reaches output limit !!!↩
↩
You must use LZMA_FINISH_END, when you know that current output buffer↩
covers last bytes of block. In other cases you must use LZMA_FINISH_ANY.↩
↩
If LZMA decoder sees end marker before reaching output limit, it returns SZ_OK,↩
and output value of destLen will be less than output buffer size limit.↩
You can check status result also.↩
↩
You can use multiple checks to test data integrity after full decompression:↩
1) Check Result and "status" variable.↩
2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize.↩
3) Check that output(srcLen) = compressedSize, if you know real compressedSize.↩
You must use correct finish mode in that case. */↩
↩
typedef enum↩
{↩
LZMA_STATUS_NOT_SPECIFIED, /* use main error code instead */↩
LZMA_STATUS_FINISHED_WITH_MARK, /* stream was finished with end mark. */↩
LZMA_STATUS_NOT_FINISHED, /* stream was not finished */↩
LZMA_STATUS_NEEDS_MORE_INPUT, /* you must provide more input bytes */↩
LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK /* there is probability that stream was finished without end mark */↩
} ELzmaStatus;↩
↩
/* ELzmaStatus is used only as output value for function call */↩
↩
↩
/* ---------- Interfaces ---------- */↩
↩
/* There are 3 levels of interfaces:↩
1) Dictionary Interface↩
2) Buffer Interface↩
3) One Call Interface↩
You can select any of these interfaces, but don't mix functions from different↩
groups for same object. */↩
↩
↩
/* There are two variants to allocate state for Dictionary Interface:↩
1) LzmaDec_Allocate / LzmaDec_Free↩
2) LzmaDec_AllocateProbs / LzmaDec_FreeProbs↩
You can use variant 2, if you set dictionary buffer manually.↩
For Buffer Interface you must always use variant 1.↩
↩
LzmaDec_Allocate* can return:↩
SZ_OK↩
SZ_ERROR_MEM - Memory allocation error↩
SZ_ERROR_UNSUPPORTED - Unsupported properties↩
*/↩
↩
SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc);↩
void LzmaDec_FreeProbs(CLzmaDec *p, ISzAllocPtr alloc);↩
↩
SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc);↩
void LzmaDec_Free(CLzmaDec *p, ISzAllocPtr alloc);↩
↩
/* ---------- Dictionary Interface ---------- */↩
↩
/* You can use it, if you want to eliminate the overhead for data copying from↩
dictionary to some other external buffer.↩
You must work with CLzmaDec variables directly in this interface.↩
↩
STEPS:↩
LzmaDec_Construct()↩
LzmaDec_Allocate()↩
for (each new stream)↩
{↩
LzmaDec_Init()↩
while (it needs more decompression)↩
{↩
LzmaDec_DecodeToDic()↩
use data from CLzmaDec::dic and update CLzmaDec::dicPos↩
}↩
}↩
LzmaDec_Free()↩
*/↩
↩
/* LzmaDec_DecodeToDic↩
↩
The decoding to internal dictionary buffer (CLzmaDec::dic).↩
You must manually update CLzmaDec::dicPos, if it reaches CLzmaDec::dicBufSize !!!↩
↩
finishMode:↩
It has meaning only if the decoding reaches output limit (dicLimit).↩
LZMA_FINISH_ANY - Decode just dicLimit bytes.↩
LZMA_FINISH_END - Stream must be finished after dicLimit.↩
↩
Returns:↩
SZ_OK↩
status:↩
LZMA_STATUS_FINISHED_WITH_MARK↩
LZMA_STATUS_NOT_FINISHED↩
LZMA_STATUS_NEEDS_MORE_INPUT↩
LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK↩
SZ_ERROR_DATA - Data error↩
*/↩
↩
SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit,↩
const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);↩
↩
↩
/* ---------- Buffer Interface ---------- */↩
↩
/* It's zlib-like interface.↩
See LzmaDec_DecodeToDic description for information about STEPS and return results,↩
but you must use LzmaDec_DecodeToBuf instead of LzmaDec_DecodeToDic and you don't need↩
to work with CLzmaDec variables manually.↩
↩
finishMode:↩
It has meaning only if the decoding reaches output limit (*destLen).↩
LZMA_FINISH_ANY - Decode just destLen bytes.↩
LZMA_FINISH_END - Stream must be finished after (*destLen).↩
*/↩
↩
SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,↩
const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);↩
↩
↩
/* ---------- One Call Interface ---------- */↩
↩
/* LzmaDecode↩
↩
finishMode:↩
It has meaning only if the decoding reaches output limit (*destLen).↩
LZMA_FINISH_ANY - Decode just destLen bytes.↩
LZMA_FINISH_END - Stream must be finished after (*destLen).↩
↩
Returns:↩
SZ_OK↩
status:↩
LZMA_STATUS_FINISHED_WITH_MARK↩
LZMA_STATUS_NOT_FINISHED↩
LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK↩
SZ_ERROR_DATA - Data error↩
SZ_ERROR_MEM - Memory allocation error↩
SZ_ERROR_UNSUPPORTED - Unsupported properties↩
SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src).↩
*/↩
↩
SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,↩
const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,↩
ELzmaStatus *status, ISzAllocPtr alloc);↩
↩
EXTERN_C_END↩
↩
#endif↩