innosetup/Components/Lzma2/Lzma2Dec.h

/* Lzma2Dec.h -- LZMA2 Decoder
2023-03-03 : Igor Pavlov : Public domain */

#ifndef ZIP7_INC_LZMA2_DEC_H
#define ZIP7_INC_LZMA2_DEC_H

#include "LzmaDec.h"

EXTERN_C_BEGIN

/* ---------- State Interface ---------- */

typedef struct
{
  unsigned state;
  Byte control;
  Byte needInitLevel;
  Byte isExtraMode;
  Byte _pad_;
  UInt32 packSize;
  UInt32 unpackSize;
  CLzmaDec decoder;
} CLzma2Dec;

#define Lzma2Dec_CONSTRUCT(p)  LzmaDec_CONSTRUCT(&(p)->decoder)
#define Lzma2Dec_Construct(p)  Lzma2Dec_CONSTRUCT(p)
#define Lzma2Dec_FreeProbs(p, alloc)  LzmaDec_FreeProbs(&(p)->decoder, alloc)
#define Lzma2Dec_Free(p, alloc)  LzmaDec_Free(&(p)->decoder, alloc)

SRes Lzma2Dec_AllocateProbs(CLzma2Dec *p, Byte prop, ISzAllocPtr alloc);
SRes Lzma2Dec_Allocate(CLzma2Dec *p, Byte prop, ISzAllocPtr alloc);
void Lzma2Dec_Init(CLzma2Dec *p);

/*
finishMode:
  It has meaning only if the decoding reaches output limit (*destLen or dicLimit).
  LZMA_FINISH_ANY - use smallest number of input bytes
  LZMA_FINISH_END - read EndOfStream marker after decoding

Returns:
  SZ_OK
    status:
      LZMA_STATUS_FINISHED_WITH_MARK
      LZMA_STATUS_NOT_FINISHED
      LZMA_STATUS_NEEDS_MORE_INPUT
  SZ_ERROR_DATA - Data error
*/

SRes Lzma2Dec_DecodeToDic(CLzma2Dec *p, SizeT dicLimit,
    const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);

SRes Lzma2Dec_DecodeToBuf(CLzma2Dec *p, Byte *dest, SizeT *destLen,
    const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status);


/* ---------- LZMA2 block and chunk parsing ---------- */

/*
Lzma2Dec_Parse() parses compressed data stream up to next independent block or next chunk data.
It can return LZMA_STATUS_* code or LZMA2_PARSE_STATUS_* code:
  - LZMA2_PARSE_STATUS_NEW_BLOCK - there is new block, and 1 additional byte (control byte of next block header) was read from input.
  - LZMA2_PARSE_STATUS_NEW_CHUNK - there is new chunk, and only lzma2 header of new chunk was read.
                                   CLzma2Dec::unpackSize contains unpack size of that chunk
*/

typedef enum
{
/*
  LZMA_STATUS_NOT_SPECIFIED                 // data error
  LZMA_STATUS_FINISHED_WITH_MARK
  LZMA_STATUS_NOT_FINISHED                  //
  LZMA_STATUS_NEEDS_MORE_INPUT
  LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK   // unused
*/
  LZMA2_PARSE_STATUS_NEW_BLOCK = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK + 1,
  LZMA2_PARSE_STATUS_NEW_CHUNK
} ELzma2ParseStatus;

ELzma2ParseStatus Lzma2Dec_Parse(CLzma2Dec *p,
    SizeT outSize,   // output size
    const Byte *src, SizeT *srcLen,
    int checkFinishBlock   // set (checkFinishBlock = 1), if it must read full input data, if decoder.dicPos reaches blockMax position.
    );

/*
LZMA2 parser doesn't decode LZMA chunks, so we must read
  full input LZMA chunk to decode some part of LZMA chunk.

Lzma2Dec_GetUnpackExtra() returns the value that shows
    max possible number of output bytes that can be output by decoder
    at current input positon.
*/

#define Lzma2Dec_GetUnpackExtra(p)  ((p)->isExtraMode ? (p)->unpackSize : 0)


/* ---------- One Call Interface ---------- */

/*
finishMode:
  It has meaning only if the decoding reaches output limit (*destLen).
  LZMA_FINISH_ANY - use smallest number of input bytes
  LZMA_FINISH_END - read EndOfStream marker after decoding

Returns:
  SZ_OK
    status:
      LZMA_STATUS_FINISHED_WITH_MARK
      LZMA_STATUS_NOT_FINISHED
  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 Lzma2Decode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
    Byte prop, ELzmaFinishMode finishMode, ELzmaStatus *status, ISzAllocPtr alloc);

EXTERN_C_END

#endif