/*
 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_CCOMMON_H_MODULE
#define ZSTD_CCOMMON_H_MODULE

/* this module contains definitions which must be identical
 * across compression, decompression and dictBuilder.
 * It also contains a few functions useful to at least 2 of them
 * and which benefit from being inlined */

/*-*************************************
 *  Dependencies
 ***************************************/
#include "compiler.h"
#include "mem.h"
#include "debug.h" /* assert, DEBUGLOG, RAWLOG, g_debuglevel */
#include "error_private.h"
#define ZSTD_STATIC_LINKING_ONLY
#include "zstd.h"
#define FSE_STATIC_LINKING_ONLY
#include "fse.h"
#define HUF_STATIC_LINKING_ONLY
#include "huf.h"
#ifndef XXH_STATIC_LINKING_ONLY
#define XXH_STATIC_LINKING_ONLY /* XXH64_state_t */
#endif
#include "xxhash.h" /* XXH_reset, update, digest */

#if defined(__cplusplus)
extern "C" {
#endif

/* ---- static assert (debug) --- */
#define ZSTD_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)
#define ZSTD_isError ERR_isError /* for inlining */
#define FSE_isError ERR_isError
#define HUF_isError ERR_isError

/*-*************************************
 *  shared macros
 ***************************************/
#undef MIN
#undef MAX
#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_REP_NUM 3 /* number of repcodes */
#define ZSTD_REP_MOVE (ZSTD_REP_NUM - 1)
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_FRAMEIDSIZE 4 /* magic number size */

#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 Litbits 8
#define MaxLit ((1 << Litbits) - 1)
#define MaxML 52
#define MaxLL 35
#define DefaultMaxOff 28
#define MaxOff 31
#define MaxSeq MAX(MaxLL, MaxML) /* Assumption : MaxOff < MaxLL,MaxML */
#define MLFSELog 9
#define LLFSELog 9
#define OffFSELog 8
#define MaxFSELog MAX(MAX(MLFSELog, LLFSELog), OffFSELog)

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[DefaultMaxOff + 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 overwrite up to WILDCOPY_OVERLENGTH bytes (if length==0) */
#define WILDCOPY_OVERLENGTH 8
MEM_STATIC void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_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 declarations
 *********************************************/
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;
  size_t maxNbSeq;
  size_t maxNbLit;
  U32 longLengthID; /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
  U32 longLengthPos;
} seqStore_t;

const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx); /* compress & dictBuilder */
void ZSTD_seqToCodes(
    const seqStore_t* seqStorePtr); /* compress, dictBuilder, decodeCorpus (shouldn't get its definition from here) */

/* custom memory allocation functions */
void* ZSTD_malloc(size_t size, ZSTD_customMem customMem);
void* ZSTD_calloc(size_t size, ZSTD_customMem customMem);
void ZSTD_free(void* ptr, ZSTD_customMem customMem);

MEM_STATIC U32 ZSTD_highbit32(U32 val) /* compress, dictBuilder, decodeCorpus */
{
  assert(val != 0);
  {
#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 U32 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;
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    return DeBruijnClz[(v * 0x07C4ACDDU) >> 27];
#endif
  }
}

/* ZSTD_invalidateRepCodes() :
 * ensures next compression will not use repcodes from previous block.
 * Note : only works with regular variant;
 *        do not use with extDict variant ! */
void ZSTD_invalidateRepCodes(
    ZSTD_CCtx* cctx); /* zstdmt, adaptive_compression (shouldn't get this definition from here) */

typedef struct {
  blockType_e blockType;
  U32 lastBlock;
  U32 origSize;
} blockProperties_t; /* declared here for decompress and fullbench */

/*! ZSTD_getcBlockSize() :
 *  Provides the size of compressed block from block header `src` */
/* Used by: decompress, fullbench (does not get its definition from here) */
size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr);

/*! ZSTD_decodeSeqHeaders() :
 *  decode sequence header from src */
/* Used by: decompress, fullbench (does not get its definition from here) */
size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr, const void* src, size_t srcSize);

#if defined(__cplusplus)
}
#endif

#endif /* ZSTD_CCOMMON_H_MODULE */