/**

 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.

 * All rights reserved.

 *

 * This source code is licensed under the BSD-style license found in the

 * LICENSE file in the root directory of this source tree. An additional grant

 * of patent rights can be found in the PATENTS file in the same directory.

 */

#ifndef ZSTD_CCOMMON_H_MODULE

#define ZSTD_CCOMMON_H_MODULE

/*-*******************************************************

*  Compiler specifics

*********************************************************/

#ifdef _MSC_VER    /* Visual Studio */

#  define FORCE_INLINE static __forceinline

#  include <intrin.h>                    /* For Visual 2005 */

#  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */

#  pragma warning(disable : 4324)        /* disable: C4324: padded structure */

#  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */

#else

#  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */

#    ifdef __GNUC__

#      define FORCE_INLINE static inline __attribute__((always_inline))

#    else

#      define FORCE_INLINE static inline

#    endif

#  else

#    define FORCE_INLINE static

#  endif /* __STDC_VERSION__ */

#endif

#ifdef _MSC_VER

#  define FORCE_NOINLINE static __declspec(noinline)

#else

#  ifdef __GNUC__

#    define FORCE_NOINLINE static __attribute__((__noinline__))

#  else

#    define FORCE_NOINLINE static

#  endif

#endif

/*-*************************************

*  Dependencies

***************************************/

#include "mem.h"

#include "error_private.h"

#define ZSTD_STATIC_LINKING_ONLY

#include "zstd.h"

/*-*************************************

*  shared macros

***************************************/

#define MIN(a,b) ((a)<(b) ? (a) : (b))

#define MAX(a,b) ((a)>(b) ? (a) : (b))

#define CHECK_F(f) { size_t const errcod = f; if (ERR_isError(errcod)) return errcod; }  /* check and Forward error code */

#define CHECK_E(f, e) { size_t const errcod = f; if (ERR_isError(errcod)) return ERROR(e); }  /* check and send Error code */

/*-*************************************

*  Common constants

***************************************/

#define ZSTD_OPT_NUM    (1<<12)

#define ZSTD_DICT_MAGIC  0xEC30A437   /* v0.7+ */

#define ZSTD_REP_NUM      3                 /* number of repcodes */

#define ZSTD_REP_CHECK    (ZSTD_REP_NUM)    /* number of repcodes to check by the optimal parser */

#define ZSTD_REP_MOVE     (ZSTD_REP_NUM-1)

#define ZSTD_REP_MOVE_OPT (ZSTD_REP_NUM)

static const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };

#define KB *(1 <<10)

#define MB *(1 <<20)

#define GB *(1U<<30)

#define BIT7 128

#define BIT6  64

#define BIT5  32

#define BIT4  16

#define BIT1   2

#define BIT0   1

#define ZSTD_WINDOWLOG_ABSOLUTEMIN 10

static const size_t ZSTD_fcs_fieldSize[4] = { 0, 2, 4, 8 };

static const size_t ZSTD_did_fieldSize[4] = { 0, 1, 2, 4 };

#define ZSTD_BLOCKHEADERSIZE 3   /* C standard doesn't allow `static const` variable to be init using another `static const` variable */

static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;

typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;

#define MIN_SEQUENCES_SIZE 1 /* nbSeq==0 */

#define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */)   /* for a non-null block */

#define HufLog 12

typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e;

#define LONGNBSEQ 0x7F00

#define MINMATCH 3

#define EQUAL_READ32 4

#define Litbits  8

#define MaxLit ((1<<Litbits) - 1)

#define MaxML  52

#define MaxLL  35

#define MaxOff 28

#define MaxSeq MAX(MaxLL, MaxML)   /* Assumption : MaxOff < MaxLL,MaxML */

#define MLFSELog    9

#define LLFSELog    9

#define OffFSELog   8

static const U32 LL_bits[MaxLL+1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

                                      1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9,10,11,12,

                                     13,14,15,16 };

static const S16 LL_defaultNorm[MaxLL+1] = { 4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1,

                                             2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1,

                                            -1,-1,-1,-1 };

#define LL_DEFAULTNORMLOG 6  /* for static allocation */

static const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;

static const U32 ML_bits[MaxML+1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

                                      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

                                      1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 9,10,11,

                                     12,13,14,15,16 };

static const S16 ML_defaultNorm[MaxML+1] = { 1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,

                                             1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

                                             1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1,

                                            -1,-1,-1,-1,-1 };

#define ML_DEFAULTNORMLOG 6  /* for static allocation */

static const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;

static const S16 OF_defaultNorm[MaxOff+1] = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,

                                              1, 1, 1, 1, 1, 1, 1, 1,-1,-1,-1,-1,-1 };

#define OF_DEFAULTNORMLOG 5  /* for static allocation */

static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;

/*-*******************************************

*  Shared functions to include for inlining

*********************************************/

static void ZSTD_copy8(void* dst, const void* src) { memcpy(dst, src, 8); }

#define COPY8(d,s) { ZSTD_copy8(d,s); d+=8; s+=8; }

/*! ZSTD_wildcopy() :

*   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */

#define WILDCOPY_OVERLENGTH 8

MEM_STATIC void ZSTD_wildcopy(void* dst, const void* src, size_t length)

{

    const BYTE* ip = (const BYTE*)src;

    BYTE* op = (BYTE*)dst;

    BYTE* const oend = op + length;

    do

        COPY8(op, ip)

    while (op < oend);

}

MEM_STATIC void ZSTD_wildcopy_e(void* dst, const void* src, void* dstEnd)   /* should be faster for decoding, but strangely, not verified on all platform */

{

    const BYTE* ip = (const BYTE*)src;

    BYTE* op = (BYTE*)dst;

    BYTE* const oend = (BYTE*)dstEnd;

    do

        COPY8(op, ip)

    while (op < oend);

}

/*-*******************************************

*  Private interfaces

*********************************************/

typedef struct ZSTD_stats_s ZSTD_stats_t;

typedef struct {

    U32 off;

    U32 len;

} ZSTD_match_t;

typedef struct {

    U32 price;

    U32 off;

    U32 mlen;

    U32 litlen;

    U32 rep[ZSTD_REP_NUM];

} ZSTD_optimal_t;

typedef struct seqDef_s {

    U32 offset;

    U16 litLength;

    U16 matchLength;

} seqDef;

typedef struct {

    seqDef* sequencesStart;

    seqDef* sequences;

    BYTE* litStart;

    BYTE* lit;

    BYTE* llCode;

    BYTE* mlCode;

    BYTE* ofCode;

    U32   longLengthID;   /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */

    U32   longLengthPos;

    /* opt */

    ZSTD_optimal_t* priceTable;

    ZSTD_match_t* matchTable;

    U32* matchLengthFreq;

    U32* litLengthFreq;

    U32* litFreq;

    U32* offCodeFreq;

    U32  matchLengthSum;

    U32  matchSum;

    U32  litLengthSum;

    U32  litSum;

    U32  offCodeSum;

    U32  log2matchLengthSum;

    U32  log2matchSum;

    U32  log2litLengthSum;

    U32  log2litSum;

    U32  log2offCodeSum;

    U32  factor;

    U32  cachedPrice;

    U32  cachedLitLength;

    const BYTE* cachedLiterals;

} seqStore_t;

const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx);

void ZSTD_seqToCodes(const seqStore_t* seqStorePtr);

int ZSTD_isSkipFrame(ZSTD_DCtx* dctx);

/* custom memory allocation functions */

void* ZSTD_defaultAllocFunction(void* opaque, size_t size);

void ZSTD_defaultFreeFunction(void* opaque, void* address);

static const ZSTD_customMem defaultCustomMem = { ZSTD_defaultAllocFunction, ZSTD_defaultFreeFunction, NULL };

void* ZSTD_malloc(size_t size, ZSTD_customMem customMem);

void ZSTD_free(void* ptr, ZSTD_customMem customMem);

/*======  common function  ======*/

MEM_STATIC U32 ZSTD_highbit32(U32 val)

{

#   if defined(_MSC_VER)   /* Visual */

    unsigned long r=0;

    _BitScanReverse(&r, val);

    return (unsigned)r;

#   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* GCC Intrinsic */

    return 31 - __builtin_clz(val);

#   else   /* Software version */

    static const int DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };

    U32 v = val;

    int r;

    v |= v >> 1;

    v |= v >> 2;

    v |= v >> 4;

    v |= v >> 8;

    v |= v >> 16;

    r = DeBruijnClz[(U32)(v * 0x07C4ACDDU) >> 27];

    return r;

#   endif

}

#endif   /* ZSTD_CCOMMON_H_MODULE */