/*
    zstd_internal - common functions to include
    Header File for include
    Copyright (C) 2014-2016, Yann Collet.

    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
    * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    You can contact the author at :
    - zstd homepage : https://www.zstd.net
*/
#ifndef ZSTD_CCOMMON_H_MODULE
#define ZSTD_CCOMMON_H_MODULE

/*-*************************************
*  Dependencies
***************************************/
#include "mem.h"
#include "error_private.h"
#define ZSTD_STATIC_LINKING_ONLY
#include "zstd.h"


/*-*************************************
*  Common macros
***************************************/
#define MIN(a,b) ((a)<(b) ? (a) : (b))
#define MAX(a,b) ((a)>(b) ? (a) : (b))


/*-*************************************
*  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 };
static const U32 LL_defaultNormLog = 6;

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 };
static const U32 ML_defaultNormLog = 6;

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 };
static const U32 OF_defaultNormLog = 5;


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