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/* LzmaDec.h -- LZMA Decoder
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2008-10-04 : Igor Pavlov : Public domain */
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#ifndef __LZMADEC_H
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#define __LZMADEC_H
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#include "LzmaTypes.h"
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/* #define _LZMA_PROB32 */
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/* _LZMA_PROB32 can increase the speed on some CPUs,
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but memory usage for CLzmaDec::probs will be doubled in that case */
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#ifdef _LZMA_PROB32
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#define CLzmaProb UInt32
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#else
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#define CLzmaProb UInt16
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#endif
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/* ---------- LZMA Properties ---------- */
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#define LZMA_PROPS_SIZE 5
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typedef struct _CLzmaProps
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{
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unsigned lc, lp, pb;
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UInt32 dicSize;
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} CLzmaProps;
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/* LzmaProps_Decode - decodes properties
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Returns:
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SZ_OK
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SZ_ERROR_UNSUPPORTED - Unsupported properties
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*/
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SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size);
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/* ---------- LZMA Decoder state ---------- */
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/* LZMA_REQUIRED_INPUT_MAX = number of required input bytes for worst case.
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Num bits = log2((2^11 / 31) ^ 22) + 26 < 134 + 26 = 160; */
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#define LZMA_REQUIRED_INPUT_MAX 20
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typedef struct
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{
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CLzmaProps prop;
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CLzmaProb *probs;
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Byte *dic;
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const Byte *buf;
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UInt32 range, code;
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SizeT dicPos;
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SizeT dicBufSize;
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UInt32 processedPos;
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UInt32 checkDicSize;
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unsigned state;
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UInt32 reps[4];
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unsigned remainLen;
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int needFlush;
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int needInitState;
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UInt32 numProbs;
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unsigned tempBufSize;
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Byte tempBuf[LZMA_REQUIRED_INPUT_MAX];
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} CLzmaDec;
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#define LzmaDec_Construct(p) { (p)->dic = 0; (p)->probs = 0; }
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void LzmaDec_Init(CLzmaDec *p);
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/* There are two types of LZMA streams:
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0) Stream with end mark. That end mark adds about 6 bytes to compressed size.
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1) Stream without end mark. You must know exact uncompressed size to decompress such stream. */
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typedef enum
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{
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LZMA_FINISH_ANY, /* finish at any point */
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LZMA_FINISH_END /* block must be finished at the end */
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} ELzmaFinishMode;
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/* ELzmaFinishMode has meaning only if the decoding reaches output limit !!!
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You must use LZMA_FINISH_END, when you know that current output buffer
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covers last bytes of block. In other cases you must use LZMA_FINISH_ANY.
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If LZMA decoder sees end marker before reaching output limit, it returns SZ_OK,
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and output value of destLen will be less than output buffer size limit.
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You can check status result also.
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You can use multiple checks to test data integrity after full decompression:
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1) Check Result and "status" variable.
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2) Check that output(destLen) = uncompressedSize, if you know real uncompressedSize.
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3) Check that output(srcLen) = compressedSize, if you know real compressedSize.
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You must use correct finish mode in that case. */
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typedef enum
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{
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LZMA_STATUS_NOT_SPECIFIED, /* use main error code instead */
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LZMA_STATUS_FINISHED_WITH_MARK, /* stream was finished with end mark. */
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LZMA_STATUS_NOT_FINISHED, /* stream was not finished */
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LZMA_STATUS_NEEDS_MORE_INPUT, /* you must provide more input bytes */
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LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK /* there is probability that stream was finished without end mark */
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} ELzmaStatus;
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/* ELzmaStatus is used only as output value for function call */
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/* ---------- Interfaces ---------- */
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/* There are 3 levels of interfaces:
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1) Dictionary Interface
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2) Buffer Interface
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3) One Call Interface
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You can select any of these interfaces, but don't mix functions from different
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groups for same object. */
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/* There are two variants to allocate state for Dictionary Interface:
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1) LzmaDec_Allocate / LzmaDec_Free
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2) LzmaDec_AllocateProbs / LzmaDec_FreeProbs
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You can use variant 2, if you set dictionary buffer manually.
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For Buffer Interface you must always use variant 1.
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LzmaDec_Allocate* can return:
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SZ_OK
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SZ_ERROR_MEM - Memory allocation error
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SZ_ERROR_UNSUPPORTED - Unsupported properties
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*/
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SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc);
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void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc);
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SRes LzmaDec_Allocate(CLzmaDec *state, const Byte *prop, unsigned propsSize, ISzAlloc *alloc);
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void LzmaDec_Free(CLzmaDec *state, ISzAlloc *alloc);
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/* ---------- Dictionary Interface ---------- */
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/* You can use it, if you want to eliminate the overhead for data copying from
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dictionary to some other external buffer.
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You must work with CLzmaDec variables directly in this interface.
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STEPS:
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LzmaDec_Constr()
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LzmaDec_Allocate()
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for (each new stream)
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{
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LzmaDec_Init()
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while (it needs more decompression)
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{
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LzmaDec_DecodeToDic()
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use data from CLzmaDec::dic and update CLzmaDec::dicPos
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}
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}
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LzmaDec_Free()
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*/
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/* LzmaDec_DecodeToDic
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The decoding to internal dictionary buffer (CLzmaDec::dic).
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You must manually update CLzmaDec::dicPos, if it reaches CLzmaDec::dicBufSize !!!
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finishMode:
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It has meaning only if the decoding reaches output limit (dicLimit).
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LZMA_FINISH_ANY - Decode just dicLimit bytes.
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LZMA_FINISH_END - Stream must be finished after dicLimit.
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Returns:
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SZ_OK
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status:
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LZMA_STATUS_FINISHED_WITH_MARK
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LZMA_STATUS_NOT_FINISHED
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LZMA_STATUS_NEEDS_MORE_INPUT
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LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
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SZ_ERROR_DATA - Data error
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*/
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SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit,
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const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
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/* ---------- Buffer Interface ---------- */
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/* It's zlib-like interface.
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See LzmaDec_DecodeToDic description for information about STEPS and return results,
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but you must use LzmaDec_DecodeToBuf instead of LzmaDec_DecodeToDic and you don't need
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to work with CLzmaDec variables manually.
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finishMode:
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It has meaning only if the decoding reaches output limit (*destLen).
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LZMA_FINISH_ANY - Decode just destLen bytes.
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LZMA_FINISH_END - Stream must be finished after (*destLen).
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*/
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SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,
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const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);
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/* ---------- One Call Interface ---------- */
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/* LzmaDecode
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finishMode:
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It has meaning only if the decoding reaches output limit (*destLen).
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LZMA_FINISH_ANY - Decode just destLen bytes.
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LZMA_FINISH_END - Stream must be finished after (*destLen).
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Returns:
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SZ_OK
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status:
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LZMA_STATUS_FINISHED_WITH_MARK
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LZMA_STATUS_NOT_FINISHED
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LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK
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SZ_ERROR_DATA - Data error
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SZ_ERROR_MEM - Memory allocation error
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SZ_ERROR_UNSUPPORTED - Unsupported properties
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SZ_ERROR_INPUT_EOF - It needs more bytes in input buffer (src).
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*/
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SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
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const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
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ELzmaStatus *status, ISzAlloc *alloc);
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#endif
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