/* Ppmd.h -- PPMD codec common code

2010-03-12 : Igor Pavlov : Public domain

This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */

#ifndef __LIBARCHIVE_BUILD

#error This header is only to be used internally to libarchive.

#endif

#ifndef ARCHIVE_PPMD_PRIVATE_H_INCLUDED

#define ARCHIVE_PPMD_PRIVATE_H_INCLUDED

#include <stddef.h>

#include "archive_read_private.h"

/*** Begin defined in Types.h ***/

#if !defined(ZCONF_H)

typedef unsigned char Byte;

#endif

typedef short Int16;

typedef unsigned short UInt16;

#ifdef _LZMA_UINT32_IS_ULONG

typedef long Int32;

typedef unsigned long UInt32;

#else

typedef int Int32;

typedef unsigned int UInt32;

#endif

#ifdef _SZ_NO_INT_64

/* define _SZ_NO_INT_64, if your compiler doesn't support 64-bit integers.

   NOTES: Some code will work incorrectly in that case! */

typedef long Int64;

typedef unsigned long UInt64;

#else

#if defined(_MSC_VER) || defined(__BORLANDC__)

typedef __int64 Int64;

typedef unsigned __int64 UInt64;

#define UINT64_CONST(n) n

#else

typedef long long int Int64;

typedef unsigned long long int UInt64;

#define UINT64_CONST(n) n ## ULL

#endif

#endif

typedef int Bool;

#define True 1

#define False 0

/* The following interfaces use first parameter as pointer to structure */

typedef struct

{

  struct archive_read *a;

  Byte (*Read)(void *p); /* reads one byte, returns 0 in case of EOF or error */

} IByteIn;

typedef struct

{

  struct archive_write *a;

  void (*Write)(void *p, Byte b);

} IByteOut;

/*** End defined in Types.h ***/

/*** Begin defined in CpuArch.h ***/

#if defined(_M_IX86) || defined(__i386__)

#define MY_CPU_X86

#endif

#if defined(MY_CPU_X86) || defined(_M_ARM)

#define MY_CPU_32BIT

#endif

#ifdef MY_CPU_32BIT

#define PPMD_32BIT

#endif

/*** End defined in CpuArch.h ***/

#define PPMD_INT_BITS 7

#define PPMD_PERIOD_BITS 7

#define PPMD_BIN_SCALE (1 << (PPMD_INT_BITS + PPMD_PERIOD_BITS))

#define PPMD_GET_MEAN_SPEC(summ, shift, round) (((summ) + (1 << ((shift) - (round)))) >> (shift))

#define PPMD_GET_MEAN(summ) PPMD_GET_MEAN_SPEC((summ), PPMD_PERIOD_BITS, 2)

#define PPMD_UPDATE_PROB_0(prob) ((prob) + (1 << PPMD_INT_BITS) - PPMD_GET_MEAN(prob))

#define PPMD_UPDATE_PROB_1(prob) ((prob) - PPMD_GET_MEAN(prob))

#define PPMD_N1 4

#define PPMD_N2 4

#define PPMD_N3 4

#define PPMD_N4 ((128 + 3 - 1 * PPMD_N1 - 2 * PPMD_N2 - 3 * PPMD_N3) / 4)

#define PPMD_NUM_INDEXES (PPMD_N1 + PPMD_N2 + PPMD_N3 + PPMD_N4)

/* SEE-contexts for PPM-contexts with masked symbols */

typedef struct

{

  UInt16 Summ; /* Freq */

  Byte Shift;  /* Speed of Freq change; low Shift is for fast change */

  Byte Count;  /* Count to next change of Shift */

} CPpmd_See;

#define Ppmd_See_Update(p)  if ((p)->Shift < PPMD_PERIOD_BITS && --(p)->Count == 0) \

    { (p)->Summ <<= 1; (p)->Count = (Byte)(3 << (p)->Shift++); }

typedef struct

{

  Byte Symbol;

  Byte Freq;

  UInt16 SuccessorLow;

  UInt16 SuccessorHigh;

} CPpmd_State;

typedef

  #ifdef PPMD_32BIT

    CPpmd_State *

  #else

    UInt32

  #endif

  CPpmd_State_Ref;

typedef

  #ifdef PPMD_32BIT

    void *

  #else

    UInt32

  #endif

  CPpmd_Void_Ref;

typedef

  #ifdef PPMD_32BIT

    Byte *

  #else

    UInt32

  #endif

  CPpmd_Byte_Ref;

#define PPMD_SetAllBitsIn256Bytes(p) \

  { unsigned j; for (j = 0; j < 256 / sizeof(p[0]); j += 8) { \

  p[j+7] = p[j+6] = p[j+5] = p[j+4] = p[j+3] = p[j+2] = p[j+1] = p[j+0] = ~(size_t)0; }}

#endif