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

 * FSE : Finite State Entropy encoder

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 *  You can contact the author at :

 *  - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy

 *  - Public forum : https://groups.google.com/forum/#!forum/lz4c

 *

 * 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.

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

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

*  Includes

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

#include "../common/compiler.h"

#include "../common/mem.h"        /* U32, U16, etc. */

#include "../common/debug.h"      /* assert, DEBUGLOG */

#include "hist.h"       /* HIST_count_wksp */

#include "../common/bitstream.h"

#define FSE_STATIC_LINKING_ONLY

#include "../common/fse.h"

#include "../common/error_private.h"

#define ZSTD_DEPS_NEED_MALLOC

#define ZSTD_DEPS_NEED_MATH64

#include "../common/zstd_deps.h"  /* ZSTD_malloc, ZSTD_free, ZSTD_memcpy, ZSTD_memset */

#include "../common/bits.h" /* ZSTD_highbit32 */

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

*  Error Management

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

#define FSE_isError ERR_isError

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

*  Templates

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

/*

  designed to be included

  for type-specific functions (template emulation in C)

  Objective is to write these functions only once, for improved maintenance

*/

/* safety checks */

#ifndef FSE_FUNCTION_EXTENSION

#  error "FSE_FUNCTION_EXTENSION must be defined"

#endif

#ifndef FSE_FUNCTION_TYPE

#  error "FSE_FUNCTION_TYPE must be defined"

#endif

/* Function names */

#define FSE_CAT(X,Y) X##Y

#define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)

#define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)

/* Function templates */

/* FSE_buildCTable_wksp() :

 * Same as FSE_buildCTable(), but using an externally allocated scratch buffer (`workSpace`).

 * wkspSize should be sized to handle worst case situation, which is `1<<max_tableLog * sizeof(FSE_FUNCTION_TYPE)`

 * workSpace must also be properly aligned with FSE_FUNCTION_TYPE requirements

 */

size_t FSE_buildCTable_wksp(FSE_CTable* ct,

                      const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog,

                            void* workSpace, size_t wkspSize)

{

    U32 const tableSize = 1 << tableLog;

    U32 const tableMask = tableSize - 1;

    void* const ptr = ct;

    U16* const tableU16 = ( (U16*) ptr) + 2;

    void* const FSCT = ((U32*)ptr) + 1 /* header */ + (tableLog ? tableSize>>1 : 1) ;

    FSE_symbolCompressionTransform* const symbolTT = (FSE_symbolCompressionTransform*) (FSCT);

    U32 const step = FSE_TABLESTEP(tableSize);

    U32 const maxSV1 = maxSymbolValue+1;

    U16* cumul = (U16*)workSpace;   /* size = maxSV1 */

    FSE_FUNCTION_TYPE* const tableSymbol = (FSE_FUNCTION_TYPE*)(cumul + (maxSV1+1));  /* size = tableSize */

    U32 highThreshold = tableSize-1;

    assert(((size_t)workSpace & 1) == 0);  /* Must be 2 bytes-aligned */

    if (FSE_BUILD_CTABLE_WORKSPACE_SIZE(maxSymbolValue, tableLog) > wkspSize) return ERROR(tableLog_tooLarge);

    /* CTable header */

    tableU16[-2] = (U16) tableLog;

    tableU16[-1] = (U16) maxSymbolValue;

    assert(tableLog < 16);   /* required for threshold strategy to work */

    /* For explanations on how to distribute symbol values over the table :

     * https://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */

     #ifdef __clang_analyzer__

     ZSTD_memset(tableSymbol, 0, sizeof(*tableSymbol) * tableSize);   /* useless initialization, just to keep scan-build happy */

     #endif

    /* symbol start positions */

    {   U32 u;

        cumul[0] = 0;

        for (u=1; u <= maxSV1; u++) {

            if (normalizedCounter[u-1]==-1) {  /* Low proba symbol */

                cumul[u] = cumul[u-1] + 1;

                tableSymbol[highThreshold--] = (FSE_FUNCTION_TYPE)(u-1);

            } else {

                assert(normalizedCounter[u-1] >= 0);

                cumul[u] = cumul[u-1] + (U16)normalizedCounter[u-1];

                assert(cumul[u] >= cumul[u-1]);  /* no overflow */

        }   }

        cumul[maxSV1] = (U16)(tableSize+1);

    }

    /* Spread symbols */

    if (highThreshold == tableSize - 1) {

        /* Case for no low prob count symbols. Lay down 8 bytes at a time

         * to reduce branch misses since we are operating on a small block

         */

        BYTE* const spread = tableSymbol + tableSize; /* size = tableSize + 8 (may write beyond tableSize) */

        {   U64 const add = 0x0101010101010101ull;

            size_t pos = 0;

            U64 sv = 0;

            U32 s;

            for (s=0; s<maxSV1; ++s, sv += add) {

                int i;

                int const n = normalizedCounter[s];

                MEM_write64(spread + pos, sv);

                for (i = 8; i < n; i += 8) {

                    MEM_write64(spread + pos + i, sv);

                }

                assert(n>=0);

                pos += (size_t)n;

            }

        }

        /* Spread symbols across the table. Lack of lowprob symbols means that

         * we don't need variable sized inner loop, so we can unroll the loop and

         * reduce branch misses.

         */

        {   size_t position = 0;

            size_t s;

            size_t const unroll = 2; /* Experimentally determined optimal unroll */

            assert(tableSize % unroll == 0); /* FSE_MIN_TABLELOG is 5 */

            for (s = 0; s < (size_t)tableSize; s += unroll) {

                size_t u;

                for (u = 0; u < unroll; ++u) {

                    size_t const uPosition = (position + (u * step)) & tableMask;

                    tableSymbol[uPosition] = spread[s + u];

                }

                position = (position + (unroll * step)) & tableMask;

            }

            assert(position == 0);   /* Must have initialized all positions */

        }

    } else {

        U32 position = 0;

        U32 symbol;

        for (symbol=0; symbol<maxSV1; symbol++) {

            int nbOccurrences;

            int const freq = normalizedCounter[symbol];

            for (nbOccurrences=0; nbOccurrences<freq; nbOccurrences++) {

                tableSymbol[position] = (FSE_FUNCTION_TYPE)symbol;

                position = (position + step) & tableMask;

                while (position > highThreshold)

                    position = (position + step) & tableMask;   /* Low proba area */

        }   }

        assert(position==0);  /* Must have initialized all positions */

    }

    /* Build table */

    {   U32 u; for (u=0; u<tableSize; u++) {

        FSE_FUNCTION_TYPE s = tableSymbol[u];   /* note : static analyzer may not understand tableSymbol is properly initialized */

        tableU16[cumul[s]++] = (U16) (tableSize+u);   /* TableU16 : sorted by symbol order; gives next state value */

    }   }

    /* Build Symbol Transformation Table */

    {   unsigned total = 0;

        unsigned s;

        for (s=0; s<=maxSymbolValue; s++) {

            switch (normalizedCounter[s])

            {

            case  0:

                /* filling nonetheless, for compatibility with FSE_getMaxNbBits() */

                symbolTT[s].deltaNbBits = ((tableLog+1) << 16) - (1<<tableLog);

                break;

            case -1:

            case  1:

                symbolTT[s].deltaNbBits = (tableLog << 16) - (1<<tableLog);

                assert(total <= INT_MAX);

                symbolTT[s].deltaFindState = (int)(total - 1);

                total ++;

                break;

            default :

                assert(normalizedCounter[s] > 1);

                {   U32 const maxBitsOut = tableLog - ZSTD_highbit32 ((U32)normalizedCounter[s]-1);

                    U32 const minStatePlus = (U32)normalizedCounter[s] << maxBitsOut;

                    symbolTT[s].deltaNbBits = (maxBitsOut << 16) - minStatePlus;

                    symbolTT[s].deltaFindState = (int)(total - (unsigned)normalizedCounter[s]);

                    total +=  (unsigned)normalizedCounter[s];

    }   }   }   }

#if 0  /* debug : symbol costs */

    DEBUGLOG(5, "\n --- table statistics : ");

    {   U32 symbol;

        for (symbol=0; symbol<=maxSymbolValue; symbol++) {

            DEBUGLOG(5, "%3u: w=%3i,   maxBits=%u, fracBits=%.2f",

                symbol, normalizedCounter[symbol],

                FSE_getMaxNbBits(symbolTT, symbol),

                (double)FSE_bitCost(symbolTT, tableLog, symbol, 8) / 256);

    }   }

#endif

    return 0;

}

#ifndef FSE_COMMONDEFS_ONLY

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

*  FSE NCount encoding

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

size_t FSE_NCountWriteBound(unsigned maxSymbolValue, unsigned tableLog)

{

    size_t const maxHeaderSize = (((maxSymbolValue+1) * tableLog

                                   + 4 /* bitCount initialized at 4 */

                                   + 2 /* first two symbols may use one additional bit each */) / 8)

                                    + 1 /* round up to whole nb bytes */

                                    + 2 /* additional two bytes for bitstream flush */;

    return maxSymbolValue ? maxHeaderSize : FSE_NCOUNTBOUND;  /* maxSymbolValue==0 ? use default */

}

static size_t

FSE_writeNCount_generic (void* header, size_t headerBufferSize,

                   const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog,

                         unsigned writeIsSafe)

{

    BYTE* const ostart = (BYTE*) header;

    BYTE* out = ostart;

    BYTE* const oend = ostart + headerBufferSize;

    int nbBits;

    const int tableSize = 1 << tableLog;

    int remaining;

    int threshold;

    U32 bitStream = 0;

    int bitCount = 0;

    unsigned symbol = 0;

    unsigned const alphabetSize = maxSymbolValue + 1;

    int previousIs0 = 0;

    /* Table Size */

    bitStream += (tableLog-FSE_MIN_TABLELOG) << bitCount;

    bitCount  += 4;

    /* Init */

    remaining = tableSize+1;   /* +1 for extra accuracy */

    threshold = tableSize;

    nbBits = tableLog+1;

    while ((symbol < alphabetSize) && (remaining>1)) {  /* stops at 1 */

        if (previousIs0) {

            unsigned start = symbol;

            while ((symbol < alphabetSize) && !normalizedCounter[symbol]) symbol++;

            if (symbol == alphabetSize) break;   /* incorrect distribution */

            while (symbol >= start+24) {

                start+=24;

                bitStream += 0xFFFFU << bitCount;

                if ((!writeIsSafe) && (out > oend-2))

                    return ERROR(dstSize_tooSmall);   /* Buffer overflow */

                out[0] = (BYTE) bitStream;

                out[1] = (BYTE)(bitStream>>8);

                out+=2;

                bitStream>>=16;

            }

            while (symbol >= start+3) {

                start+=3;

                bitStream += 3 << bitCount;

                bitCount += 2;

            }

            bitStream += (symbol-start) << bitCount;

            bitCount += 2;

            if (bitCount>16) {

                if ((!writeIsSafe) && (out > oend - 2))

                    return ERROR(dstSize_tooSmall);   /* Buffer overflow */

                out[0] = (BYTE)bitStream;

                out[1] = (BYTE)(bitStream>>8);

                out += 2;

                bitStream >>= 16;

                bitCount -= 16;

        }   }

        {   int count = normalizedCounter[symbol++];

            int const max = (2*threshold-1) - remaining;

            remaining -= count < 0 ? -count : count;

            count++;   /* +1 for extra accuracy */

            if (count>=threshold)

                count += max;   /* [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ */

            bitStream += count << bitCount;

            bitCount  += nbBits;

            bitCount  -= (count<max);

            previousIs0  = (count==1);

            if (remaining<1) return ERROR(GENERIC);

            while (remaining<threshold) { nbBits--; threshold>>=1; }

        }

        if (bitCount>16) {

            if ((!writeIsSafe) && (out > oend - 2))

                return ERROR(dstSize_tooSmall);   /* Buffer overflow */

            out[0] = (BYTE)bitStream;

            out[1] = (BYTE)(bitStream>>8);

            out += 2;

            bitStream >>= 16;

            bitCount -= 16;

    }   }

    if (remaining != 1)

        return ERROR(GENERIC);  /* incorrect normalized distribution */

    assert(symbol <= alphabetSize);

    /* flush remaining bitStream */

    if ((!writeIsSafe) && (out > oend - 2))

        return ERROR(dstSize_tooSmall);   /* Buffer overflow */

    out[0] = (BYTE)bitStream;

    out[1] = (BYTE)(bitStream>>8);

    out+= (bitCount+7) /8;

    return (out-ostart);

}

size_t FSE_writeNCount (void* buffer, size_t bufferSize,

                  const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)

{

    if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);   /* Unsupported */

    if (tableLog < FSE_MIN_TABLELOG) return ERROR(GENERIC);   /* Unsupported */

    if (bufferSize < FSE_NCountWriteBound(maxSymbolValue, tableLog))

        return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 0);

    return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 1 /* write in buffer is safe */);

}

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

*  FSE Compression Code

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

/* provides the minimum logSize to safely represent a distribution */

static unsigned FSE_minTableLog(size_t srcSize, unsigned maxSymbolValue)

{

    U32 minBitsSrc = ZSTD_highbit32((U32)(srcSize)) + 1;

    U32 minBitsSymbols = ZSTD_highbit32(maxSymbolValue) + 2;

    U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols;

    assert(srcSize > 1); /* Not supported, RLE should be used instead */

    return minBits;

}

unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus)

{

    U32 maxBitsSrc = ZSTD_highbit32((U32)(srcSize - 1)) - minus;

    U32 tableLog = maxTableLog;

    U32 minBits = FSE_minTableLog(srcSize, maxSymbolValue);

    assert(srcSize > 1); /* Not supported, RLE should be used instead */

    if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG;

    if (maxBitsSrc < tableLog) tableLog = maxBitsSrc;   /* Accuracy can be reduced */

    if (minBits > tableLog) tableLog = minBits;   /* Need a minimum to safely represent all symbol values */

    if (tableLog < FSE_MIN_TABLELOG) tableLog = FSE_MIN_TABLELOG;

    if (tableLog > FSE_MAX_TABLELOG) tableLog = FSE_MAX_TABLELOG;

    return tableLog;

}

unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue)

{

    return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 2);

}

/* Secondary normalization method.

   To be used when primary method fails. */

static size_t FSE_normalizeM2(short* norm, U32 tableLog, const unsigned* count, size_t total, U32 maxSymbolValue, short lowProbCount)

{

    short const NOT_YET_ASSIGNED = -2;

    U32 s;

    U32 distributed = 0;

    U32 ToDistribute;

    /* Init */

    U32 const lowThreshold = (U32)(total >> tableLog);

    U32 lowOne = (U32)((total * 3) >> (tableLog + 1));

    for (s=0; s<=maxSymbolValue; s++) {

        if (count[s] == 0) {

            norm[s]=0;

            continue;

        }

        if (count[s] <= lowThreshold) {

            norm[s] = lowProbCount;

            distributed++;

            total -= count[s];

            continue;

        }

        if (count[s] <= lowOne) {

            norm[s] = 1;

            distributed++;

            total -= count[s];

            continue;

        }

        norm[s]=NOT_YET_ASSIGNED;

    }

    ToDistribute = (1 << tableLog) - distributed;

    if (ToDistribute == 0)

        return 0;

    if ((total / ToDistribute) > lowOne) {

        /* risk of rounding to zero */

        lowOne = (U32)((total * 3) / (ToDistribute * 2));

        for (s=0; s<=maxSymbolValue; s++) {

            if ((norm[s] == NOT_YET_ASSIGNED) && (count[s] <= lowOne)) {

                norm[s] = 1;

                distributed++;

                total -= count[s];

                continue;

        }   }

        ToDistribute = (1 << tableLog) - distributed;

    }

    if (distributed == maxSymbolValue+1) {

        /* all values are pretty poor;

           probably incompressible data (should have already been detected);

           find max, then give all remaining points to max */

        U32 maxV = 0, maxC = 0;

        for (s=0; s<=maxSymbolValue; s++)

            if (count[s] > maxC) { maxV=s; maxC=count[s]; }

        norm[maxV] += (short)ToDistribute;

        return 0;

    }

    if (total == 0) {

        /* all of the symbols were low enough for the lowOne or lowThreshold */

        for (s=0; ToDistribute > 0; s = (s+1)%(maxSymbolValue+1))

            if (norm[s] > 0) { ToDistribute--; norm[s]++; }

        return 0;

    }

    {   U64 const vStepLog = 62 - tableLog;

        U64 const mid = (1ULL << (vStepLog-1)) - 1;

        U64 const rStep = ZSTD_div64((((U64)1<<vStepLog) * ToDistribute) + mid, (U32)total);   /* scale on remaining */

        U64 tmpTotal = mid;

        for (s=0; s<=maxSymbolValue; s++) {

            if (norm[s]==NOT_YET_ASSIGNED) {

                U64 const end = tmpTotal + (count[s] * rStep);

                U32 const sStart = (U32)(tmpTotal >> vStepLog);

                U32 const sEnd = (U32)(end >> vStepLog);

                U32 const weight = sEnd - sStart;

                if (weight < 1)

                    return ERROR(GENERIC);

                norm[s] = (short)weight;

                tmpTotal = end;

    }   }   }

    return 0;

}

size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog,

                           const unsigned* count, size_t total,

                           unsigned maxSymbolValue, unsigned useLowProbCount)

{

    /* Sanity checks */

    if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG;

    if (tableLog < FSE_MIN_TABLELOG) return ERROR(GENERIC);   /* Unsupported size */

    if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);   /* Unsupported size */

    if (tableLog < FSE_minTableLog(total, maxSymbolValue)) return ERROR(GENERIC);   /* Too small tableLog, compression potentially impossible */

    {   static U32 const rtbTable[] = {     0, 473195, 504333, 520860, 550000, 700000, 750000, 830000 };

        short const lowProbCount = useLowProbCount ? -1 : 1;

        U64 const scale = 62 - tableLog;

        U64 const step = ZSTD_div64((U64)1<<62, (U32)total);   /* <== here, one division ! */

        U64 const vStep = 1ULL<<(scale-20);

        int stillToDistribute = 1<<tableLog;

        unsigned s;

        unsigned largest=0;

        short largestP=0;

        U32 lowThreshold = (U32)(total >> tableLog);

        for (s=0; s<=maxSymbolValue; s++) {

            if (count[s] == total) return 0;   /* rle special case */

            if (count[s] == 0) { normalizedCounter[s]=0; continue; }

            if (count[s] <= lowThreshold) {

                normalizedCounter[s] = lowProbCount;

                stillToDistribute--;

            } else {

                short proba = (short)((count[s]*step) >> scale);

                if (proba<8) {

                    U64 restToBeat = vStep * rtbTable[proba];

                    proba += (count[s]*step) - ((U64)proba<<scale) > restToBeat;

                }

                if (proba > largestP) { largestP=proba; largest=s; }

                normalizedCounter[s] = proba;

                stillToDistribute -= proba;

        }   }

        if (-stillToDistribute >= (normalizedCounter[largest] >> 1)) {

            /* corner case, need another normalization method */

            size_t const errorCode = FSE_normalizeM2(normalizedCounter, tableLog, count, total, maxSymbolValue, lowProbCount);

            if (FSE_isError(errorCode)) return errorCode;

        }

        else normalizedCounter[largest] += (short)stillToDistribute;

    }

#if 0

    {   /* Print Table (debug) */

        U32 s;

        U32 nTotal = 0;

        for (s=0; s<=maxSymbolValue; s++)

            RAWLOG(2, "%3i: %4i \n", s, normalizedCounter[s]);

        for (s=0; s<=maxSymbolValue; s++)

            nTotal += abs(normalizedCounter[s]);

        if (nTotal != (1U<<tableLog))

            RAWLOG(2, "Warning !!! Total == %u != %u !!!", nTotal, 1U<<tableLog);

        getchar();

    }

#endif

    return tableLog;

}

/* fake FSE_CTable, for rle input (always same symbol) */

size_t FSE_buildCTable_rle (FSE_CTable* ct, BYTE symbolValue)

{

    void* ptr = ct;

    U16* tableU16 = ( (U16*) ptr) + 2;

    void* FSCTptr = (U32*)ptr + 2;

    FSE_symbolCompressionTransform* symbolTT = (FSE_symbolCompressionTransform*) FSCTptr;

    /* header */

    tableU16[-2] = (U16) 0;

    tableU16[-1] = (U16) symbolValue;

    /* Build table */

    tableU16[0] = 0;

    tableU16[1] = 0;   /* just in case */

    /* Build Symbol Transformation Table */

    symbolTT[symbolValue].deltaNbBits = 0;

    symbolTT[symbolValue].deltaFindState = 0;

    return 0;

}

static size_t FSE_compress_usingCTable_generic (void* dst, size_t dstSize,

                           const void* src, size_t srcSize,

                           const FSE_CTable* ct, const unsigned fast)

{

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

    const BYTE* const iend = istart + srcSize;

    const BYTE* ip=iend;

    BIT_CStream_t bitC;

    FSE_CState_t CState1, CState2;

    /* init */

    if (srcSize <= 2) return 0;

    { size_t const initError = BIT_initCStream(&bitC, dst, dstSize);

      if (FSE_isError(initError)) return 0; /* not enough space available to write a bitstream */ }

#define FSE_FLUSHBITS(s)  (fast ? BIT_flushBitsFast(s) : BIT_flushBits(s))

    if (srcSize & 1) {

        FSE_initCState2(&CState1, ct, *--ip);

        FSE_initCState2(&CState2, ct, *--ip);

        FSE_encodeSymbol(&bitC, &CState1, *--ip);

        FSE_FLUSHBITS(&bitC);

    } else {

        FSE_initCState2(&CState2, ct, *--ip);

        FSE_initCState2(&CState1, ct, *--ip);

    }

    /* join to mod 4 */

    srcSize -= 2;

    if ((sizeof(bitC.bitContainer)*8 > FSE_MAX_TABLELOG*4+7 ) && (srcSize & 2)) {  /* test bit 2 */

        FSE_encodeSymbol(&bitC, &CState2, *--ip);

        FSE_encodeSymbol(&bitC, &CState1, *--ip);

        FSE_FLUSHBITS(&bitC);

    }

    /* 2 or 4 encoding per loop */

    while ( ip>istart ) {

        FSE_encodeSymbol(&bitC, &CState2, *--ip);

        if (sizeof(bitC.bitContainer)*8 < FSE_MAX_TABLELOG*2+7 )   /* this test must be static */

            FSE_FLUSHBITS(&bitC);

        FSE_encodeSymbol(&bitC, &CState1, *--ip);

        if (sizeof(bitC.bitContainer)*8 > FSE_MAX_TABLELOG*4+7 ) {  /* this test must be static */

            FSE_encodeSymbol(&bitC, &CState2, *--ip);

            FSE_encodeSymbol(&bitC, &CState1, *--ip);

        }

        FSE_FLUSHBITS(&bitC);

    }

    FSE_flushCState(&bitC, &CState2);

    FSE_flushCState(&bitC, &CState1);

    return BIT_closeCStream(&bitC);

}

size_t FSE_compress_usingCTable (void* dst, size_t dstSize,

                           const void* src, size_t srcSize,

                           const FSE_CTable* ct)

{

    unsigned const fast = (dstSize >= FSE_BLOCKBOUND(srcSize));

    if (fast)

        return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 1);

    else

        return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 0);

}

size_t FSE_compressBound(size_t size) { return FSE_COMPRESSBOUND(size); }

#endif   /* FSE_COMMONDEFS_ONLY */