/* 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