/* 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 | |
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; } | |
void LzmaDec_Init(CLzmaDec *p); | |
/* 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 |