/**

 * 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.

 */

/* ======   Tuning parameters   ====== */

#define ZSTDMT_NBTHREADS_MAX 128

/* ======   Compiler specifics   ====== */

#if defined(_MSC_VER)

#  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */

#endif

/* ======   Dependencies   ====== */

#include <stdlib.h>   /* malloc */

#include <string.h>   /* memcpy */

#include "pool.h"     /* threadpool */

#include "threading.h"  /* mutex */

#include "zstd_internal.h"   /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */

#include "zstdmt_compress.h"

#define XXH_STATIC_LINKING_ONLY   /* XXH64_state_t */

#include "xxhash.h"

/* ======   Debug   ====== */

#if 0

#  include <stdio.h>

#  include <unistd.h>

#  include <sys/times.h>

   static unsigned g_debugLevel = 3;

#  define DEBUGLOGRAW(l, ...) if (l<=g_debugLevel) { fprintf(stderr, __VA_ARGS__); }

#  define DEBUGLOG(l, ...) if (l<=g_debugLevel) { fprintf(stderr, __FILE__ ": "); fprintf(stderr, __VA_ARGS__); fprintf(stderr, " \n"); }

#  define DEBUG_PRINTHEX(l,p,n) { \

    unsigned debug_u;                   \

    for (debug_u=0; debug_u<(n); debug_u++)           \

        DEBUGLOGRAW(l, "%02X ", ((const unsigned char*)(p))[debug_u]); \

    DEBUGLOGRAW(l, " \n");       \

}

static unsigned long long GetCurrentClockTimeMicroseconds()

{

   static clock_t _ticksPerSecond = 0;

   if (_ticksPerSecond <= 0) _ticksPerSecond = sysconf(_SC_CLK_TCK);

   struct tms junk; clock_t newTicks = (clock_t) times(&junk);

   return ((((unsigned long long)newTicks)*(1000000))/_ticksPerSecond);

}

#define MUTEX_WAIT_TIME_DLEVEL 5

#define PTHREAD_MUTEX_LOCK(mutex) \

if (g_debugLevel>=MUTEX_WAIT_TIME_DLEVEL) { \

   unsigned long long beforeTime = GetCurrentClockTimeMicroseconds(); \

   pthread_mutex_lock(mutex); \

   unsigned long long afterTime = GetCurrentClockTimeMicroseconds(); \

   unsigned long long elapsedTime = (afterTime-beforeTime); \

   if (elapsedTime > 1000) {  /* or whatever threshold you like; I'm using 1 millisecond here */ \

      DEBUGLOG(MUTEX_WAIT_TIME_DLEVEL, "Thread took %llu microseconds to acquire mutex %s \n", \

               elapsedTime, #mutex); \

  } \

} else pthread_mutex_lock(mutex);

#else

#  define DEBUGLOG(l, ...)      {}    /* disabled */

#  define PTHREAD_MUTEX_LOCK(m) pthread_mutex_lock(m)

#  define DEBUG_PRINTHEX(l,p,n) {}

#endif

/* =====   Buffer Pool   ===== */

typedef struct buffer_s {

    void* start;

    size_t size;

} buffer_t;

static const buffer_t g_nullBuffer = { NULL, 0 };

typedef struct ZSTDMT_bufferPool_s {

    unsigned totalBuffers;

    unsigned nbBuffers;

    buffer_t bTable[1];   /* variable size */

} ZSTDMT_bufferPool;

static ZSTDMT_bufferPool* ZSTDMT_createBufferPool(unsigned nbThreads)

{

    unsigned const maxNbBuffers = 2*nbThreads + 2;

    ZSTDMT_bufferPool* const bufPool = (ZSTDMT_bufferPool*)calloc(1, sizeof(ZSTDMT_bufferPool) + (maxNbBuffers-1) * sizeof(buffer_t));

    if (bufPool==NULL) return NULL;

    bufPool->totalBuffers = maxNbBuffers;

    bufPool->nbBuffers = 0;

    return bufPool;

}

static void ZSTDMT_freeBufferPool(ZSTDMT_bufferPool* bufPool)

{

    unsigned u;

    if (!bufPool) return;   /* compatibility with free on NULL */

    for (u=0; u<bufPool->totalBuffers; u++)

        free(bufPool->bTable[u].start);

    free(bufPool);

}

/* assumption : invocation from main thread only ! */

static buffer_t ZSTDMT_getBuffer(ZSTDMT_bufferPool* pool, size_t bSize)

{

    if (pool->nbBuffers) {   /* try to use an existing buffer */

        buffer_t const buf = pool->bTable[--(pool->nbBuffers)];

        size_t const availBufferSize = buf.size;

        if ((availBufferSize >= bSize) & (availBufferSize <= 10*bSize))   /* large enough, but not too much */

            return buf;

        free(buf.start);   /* size conditions not respected : scratch this buffer and create a new one */

    }

    /* create new buffer */

    {   buffer_t buffer;

        void* const start = malloc(bSize);

        if (start==NULL) bSize = 0;

        buffer.start = start;   /* note : start can be NULL if malloc fails ! */

        buffer.size = bSize;

        return buffer;

    }

}

/* store buffer for later re-use, up to pool capacity */

static void ZSTDMT_releaseBuffer(ZSTDMT_bufferPool* pool, buffer_t buf)

{

    if (buf.start == NULL) return;   /* release on NULL */

    if (pool->nbBuffers < pool->totalBuffers) {

        pool->bTable[pool->nbBuffers++] = buf;   /* store for later re-use */

        return;

    }

    /* Reached bufferPool capacity (should not happen) */

    free(buf.start);

}

/* =====   CCtx Pool   ===== */

typedef struct {

    unsigned totalCCtx;

    unsigned availCCtx;

    ZSTD_CCtx* cctx[1];   /* variable size */

} ZSTDMT_CCtxPool;

/* assumption : CCtxPool invocation only from main thread */

/* note : all CCtx borrowed from the pool should be released back to the pool _before_ freeing the pool */

static void ZSTDMT_freeCCtxPool(ZSTDMT_CCtxPool* pool)

{

    unsigned u;

    for (u=0; u<pool->totalCCtx; u++)

        ZSTD_freeCCtx(pool->cctx[u]);  /* note : compatible with free on NULL */

    free(pool);

}

/* ZSTDMT_createCCtxPool() :

 * implies nbThreads >= 1 , checked by caller ZSTDMT_createCCtx() */

static ZSTDMT_CCtxPool* ZSTDMT_createCCtxPool(unsigned nbThreads)

{

    ZSTDMT_CCtxPool* const cctxPool = (ZSTDMT_CCtxPool*) calloc(1, sizeof(ZSTDMT_CCtxPool) + (nbThreads-1)*sizeof(ZSTD_CCtx*));

    if (!cctxPool) return NULL;

    cctxPool->totalCCtx = nbThreads;

    cctxPool->availCCtx = 1;   /* at least one cctx for single-thread mode */

    cctxPool->cctx[0] = ZSTD_createCCtx();

    if (!cctxPool->cctx[0]) { ZSTDMT_freeCCtxPool(cctxPool); return NULL; }

    DEBUGLOG(1, "cctxPool created, with %u threads", nbThreads);

    return cctxPool;

}

static ZSTD_CCtx* ZSTDMT_getCCtx(ZSTDMT_CCtxPool* pool)

{

    if (pool->availCCtx) {

        pool->availCCtx--;

        return pool->cctx[pool->availCCtx];

    }

    return ZSTD_createCCtx();   /* note : can be NULL, when creation fails ! */

}

static void ZSTDMT_releaseCCtx(ZSTDMT_CCtxPool* pool, ZSTD_CCtx* cctx)

{

    if (cctx==NULL) return;   /* compatibility with release on NULL */

    if (pool->availCCtx < pool->totalCCtx)

        pool->cctx[pool->availCCtx++] = cctx;

    else

        /* pool overflow : should not happen, since totalCCtx==nbThreads */

        ZSTD_freeCCtx(cctx);

}

/* =====   Thread worker   ===== */

typedef struct {

    buffer_t buffer;

    size_t filled;

} inBuff_t;

typedef struct {

    ZSTD_CCtx* cctx;

    buffer_t src;

    const void* srcStart;

    size_t   srcSize;

    size_t   dictSize;

    buffer_t dstBuff;

    size_t   cSize;

    size_t   dstFlushed;

    unsigned firstChunk;

    unsigned lastChunk;

    unsigned jobCompleted;

    unsigned jobScanned;

    pthread_mutex_t* jobCompleted_mutex;

    pthread_cond_t* jobCompleted_cond;

    ZSTD_parameters params;

    ZSTD_CDict* cdict;

    unsigned long long fullFrameSize;

} ZSTDMT_jobDescription;

/* ZSTDMT_compressChunk() : POOL_function type */

void ZSTDMT_compressChunk(void* jobDescription)

{

    ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)jobDescription;

    const void* const src = (const char*)job->srcStart + job->dictSize;

    buffer_t const dstBuff = job->dstBuff;

    DEBUGLOG(3, "job (first:%u) (last:%u) : dictSize %u, srcSize %u", job->firstChunk, job->lastChunk, (U32)job->dictSize, (U32)job->srcSize);

    if (job->cdict) {

        size_t const initError = ZSTD_compressBegin_usingCDict(job->cctx, job->cdict, job->fullFrameSize);

        if (job->cdict) DEBUGLOG(3, "using CDict ");

        if (ZSTD_isError(initError)) { job->cSize = initError; goto _endJob; }

    } else {

        size_t const initError = ZSTD_compressBegin_advanced(job->cctx, job->srcStart, job->dictSize, job->params, job->fullFrameSize);

        if (ZSTD_isError(initError)) { job->cSize = initError; goto _endJob; }

        ZSTD_setCCtxParameter(job->cctx, ZSTD_p_forceWindow, 1);

    }

    if (!job->firstChunk) {  /* flush frame header */

        size_t const hSize = ZSTD_compressContinue(job->cctx, dstBuff.start, dstBuff.size, src, 0);

        if (ZSTD_isError(hSize)) { job->cSize = hSize; goto _endJob; }

        ZSTD_invalidateRepCodes(job->cctx);

    }

    DEBUGLOG(4, "Compressing : ");

    DEBUG_PRINTHEX(4, job->srcStart, 12);

    job->cSize = (job->lastChunk) ?   /* last chunk signal */

                 ZSTD_compressEnd     (job->cctx, dstBuff.start, dstBuff.size, src, job->srcSize) :

                 ZSTD_compressContinue(job->cctx, dstBuff.start, dstBuff.size, src, job->srcSize);

    DEBUGLOG(3, "compressed %u bytes into %u bytes   (first:%u) (last:%u)", (unsigned)job->srcSize, (unsigned)job->cSize, job->firstChunk, job->lastChunk);

_endJob:

    PTHREAD_MUTEX_LOCK(job->jobCompleted_mutex);

    job->jobCompleted = 1;

    job->jobScanned = 0;

    pthread_cond_signal(job->jobCompleted_cond);

    pthread_mutex_unlock(job->jobCompleted_mutex);

}

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

/* =====   Multi-threaded compression   ===== */

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

struct ZSTDMT_CCtx_s {

    POOL_ctx* factory;

    ZSTDMT_bufferPool* buffPool;

    ZSTDMT_CCtxPool* cctxPool;

    pthread_mutex_t jobCompleted_mutex;

    pthread_cond_t jobCompleted_cond;

    size_t targetSectionSize;

    size_t marginSize;

    size_t inBuffSize;

    size_t dictSize;

    size_t targetDictSize;

    inBuff_t inBuff;

    ZSTD_parameters params;

    XXH64_state_t xxhState;

    unsigned nbThreads;

    unsigned jobIDMask;

    unsigned doneJobID;

    unsigned nextJobID;

    unsigned frameEnded;

    unsigned allJobsCompleted;

    unsigned overlapRLog;

    unsigned long long frameContentSize;

    size_t sectionSize;

    ZSTD_CDict* cdict;

    ZSTD_CStream* cstream;

    ZSTDMT_jobDescription jobs[1];   /* variable size (must lies at the end) */

};

ZSTDMT_CCtx *ZSTDMT_createCCtx(unsigned nbThreads)

{

    ZSTDMT_CCtx* cctx;

    U32 const minNbJobs = nbThreads + 2;

    U32 const nbJobsLog2 = ZSTD_highbit32(minNbJobs) + 1;

    U32 const nbJobs = 1 << nbJobsLog2;

    DEBUGLOG(5, "nbThreads : %u  ; minNbJobs : %u ;  nbJobsLog2 : %u ;  nbJobs : %u  \n",

            nbThreads, minNbJobs, nbJobsLog2, nbJobs);

    if ((nbThreads < 1) | (nbThreads > ZSTDMT_NBTHREADS_MAX)) return NULL;

    cctx = (ZSTDMT_CCtx*) calloc(1, sizeof(ZSTDMT_CCtx) + nbJobs*sizeof(ZSTDMT_jobDescription));

    if (!cctx) return NULL;

    cctx->nbThreads = nbThreads;

    cctx->jobIDMask = nbJobs - 1;

    cctx->allJobsCompleted = 1;

    cctx->sectionSize = 0;

    cctx->overlapRLog = 3;

    cctx->factory = POOL_create(nbThreads, 1);

    cctx->buffPool = ZSTDMT_createBufferPool(nbThreads);

    cctx->cctxPool = ZSTDMT_createCCtxPool(nbThreads);

    if (!cctx->factory | !cctx->buffPool | !cctx->cctxPool) {  /* one object was not created */

        ZSTDMT_freeCCtx(cctx);

        return NULL;

    }

    if (nbThreads==1) {

        cctx->cstream = ZSTD_createCStream();

        if (!cctx->cstream) {

            ZSTDMT_freeCCtx(cctx); return NULL;

    }   }

    pthread_mutex_init(&cctx->jobCompleted_mutex, NULL);   /* Todo : check init function return */

    pthread_cond_init(&cctx->jobCompleted_cond, NULL);

    DEBUGLOG(4, "mt_cctx created, for %u threads \n", nbThreads);

    return cctx;

}

/* ZSTDMT_releaseAllJobResources() :

 * Ensure all workers are killed first. */

static void ZSTDMT_releaseAllJobResources(ZSTDMT_CCtx* mtctx)

{

    unsigned jobID;

    for (jobID=0; jobID <= mtctx->jobIDMask; jobID++) {

        ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->jobs[jobID].dstBuff);

        mtctx->jobs[jobID].dstBuff = g_nullBuffer;

        ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->jobs[jobID].src);

        mtctx->jobs[jobID].src = g_nullBuffer;

        ZSTDMT_releaseCCtx(mtctx->cctxPool, mtctx->jobs[jobID].cctx);

        mtctx->jobs[jobID].cctx = NULL;

    }

    memset(mtctx->jobs, 0, (mtctx->jobIDMask+1)*sizeof(ZSTDMT_jobDescription));

    ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->inBuff.buffer);

    mtctx->inBuff.buffer = g_nullBuffer;

    mtctx->allJobsCompleted = 1;

}

size_t ZSTDMT_freeCCtx(ZSTDMT_CCtx* mtctx)

{

    if (mtctx==NULL) return 0;   /* compatible with free on NULL */

    POOL_free(mtctx->factory);

    if (!mtctx->allJobsCompleted) ZSTDMT_releaseAllJobResources(mtctx); /* stop workers first */

    ZSTDMT_freeBufferPool(mtctx->buffPool);  /* release job resources into pools first */

    ZSTDMT_freeCCtxPool(mtctx->cctxPool);

    ZSTD_freeCDict(mtctx->cdict);

    ZSTD_freeCStream(mtctx->cstream);

    pthread_mutex_destroy(&mtctx->jobCompleted_mutex);

    pthread_cond_destroy(&mtctx->jobCompleted_cond);

    free(mtctx);

    return 0;

}

size_t ZSTDMT_setMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSDTMT_parameter parameter, unsigned value)

{

    switch(parameter)

    {

    case ZSTDMT_p_sectionSize :

        mtctx->sectionSize = value;

        return 0;

    case ZSTDMT_p_overlapSectionLog :

    DEBUGLOG(4, "ZSTDMT_p_overlapSectionLog : %u", value);

        mtctx->overlapRLog = (value >= 9) ? 0 : 9 - value;

        return 0;

    default :

        return ERROR(compressionParameter_unsupported);

    }

}

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

/* =====   Multi-threaded compression   ===== */

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

size_t ZSTDMT_compressCCtx(ZSTDMT_CCtx* mtctx,

                           void* dst, size_t dstCapacity,

                     const void* src, size_t srcSize,

                           int compressionLevel)

{

    ZSTD_parameters params = ZSTD_getParams(compressionLevel, srcSize, 0);

    size_t const chunkTargetSize = (size_t)1 << (params.cParams.windowLog + 2);

    unsigned const nbChunksMax = (unsigned)(srcSize / chunkTargetSize) + (srcSize < chunkTargetSize) /* min 1 */;

    unsigned nbChunks = MIN(nbChunksMax, mtctx->nbThreads);

    size_t const proposedChunkSize = (srcSize + (nbChunks-1)) / nbChunks;

    size_t const avgChunkSize = ((proposedChunkSize & 0x1FFFF) < 0xFFFF) ? proposedChunkSize + 0xFFFF : proposedChunkSize;   /* avoid too small last block */

    size_t remainingSrcSize = srcSize;

    const char* const srcStart = (const char*)src;

    size_t frameStartPos = 0;

    DEBUGLOG(3, "windowLog : %2u => chunkTargetSize : %u bytes  ", params.cParams.windowLog, (U32)chunkTargetSize);

    DEBUGLOG(2, "nbChunks  : %2u   (chunkSize : %u bytes)   ", nbChunks, (U32)avgChunkSize);

    params.fParams.contentSizeFlag = 1;

    if (nbChunks==1) {   /* fallback to single-thread mode */

        ZSTD_CCtx* const cctx = mtctx->cctxPool->cctx[0];

        return ZSTD_compressCCtx(cctx, dst, dstCapacity, src, srcSize, compressionLevel);

    }

    {   unsigned u;

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

            size_t const chunkSize = MIN(remainingSrcSize, avgChunkSize);

            size_t const dstBufferCapacity = u ? ZSTD_compressBound(chunkSize) : dstCapacity;

            buffer_t const dstAsBuffer = { dst, dstCapacity };

            buffer_t const dstBuffer = u ? ZSTDMT_getBuffer(mtctx->buffPool, dstBufferCapacity) : dstAsBuffer;

            ZSTD_CCtx* const cctx = ZSTDMT_getCCtx(mtctx->cctxPool);

            if ((cctx==NULL) || (dstBuffer.start==NULL)) {

                mtctx->jobs[u].cSize = ERROR(memory_allocation);   /* job result */

                mtctx->jobs[u].jobCompleted = 1;

                nbChunks = u+1;

                break;   /* let's wait for previous jobs to complete, but don't start new ones */

            }

            mtctx->jobs[u].srcStart = srcStart + frameStartPos;

            mtctx->jobs[u].srcSize = chunkSize;

            mtctx->jobs[u].fullFrameSize = srcSize;

            mtctx->jobs[u].params = params;

            mtctx->jobs[u].dstBuff = dstBuffer;

            mtctx->jobs[u].cctx = cctx;

            mtctx->jobs[u].firstChunk = (u==0);

            mtctx->jobs[u].lastChunk = (u==nbChunks-1);

            mtctx->jobs[u].jobCompleted = 0;

            mtctx->jobs[u].jobCompleted_mutex = &mtctx->jobCompleted_mutex;

            mtctx->jobs[u].jobCompleted_cond = &mtctx->jobCompleted_cond;

            DEBUGLOG(3, "posting job %u   (%u bytes)", u, (U32)chunkSize);

            DEBUG_PRINTHEX(3, mtctx->jobs[u].srcStart, 12);

            POOL_add(mtctx->factory, ZSTDMT_compressChunk, &mtctx->jobs[u]);

            frameStartPos += chunkSize;

            remainingSrcSize -= chunkSize;

    }   }

    /* note : since nbChunks <= nbThreads, all jobs should be running immediately in parallel */

    {   unsigned chunkID;

        size_t error = 0, dstPos = 0;

        for (chunkID=0; chunkID<nbChunks; chunkID++) {

            DEBUGLOG(3, "waiting for chunk %u ", chunkID);

            PTHREAD_MUTEX_LOCK(&mtctx->jobCompleted_mutex);

            while (mtctx->jobs[chunkID].jobCompleted==0) {

                DEBUGLOG(4, "waiting for jobCompleted signal from chunk %u", chunkID);

                pthread_cond_wait(&mtctx->jobCompleted_cond, &mtctx->jobCompleted_mutex);

            }

            pthread_mutex_unlock(&mtctx->jobCompleted_mutex);

            DEBUGLOG(3, "ready to write chunk %u ", chunkID);

            ZSTDMT_releaseCCtx(mtctx->cctxPool, mtctx->jobs[chunkID].cctx);

            mtctx->jobs[chunkID].cctx = NULL;

            mtctx->jobs[chunkID].srcStart = NULL;

            {   size_t const cSize = mtctx->jobs[chunkID].cSize;

                if (ZSTD_isError(cSize)) error = cSize;

                if ((!error) && (dstPos + cSize > dstCapacity)) error = ERROR(dstSize_tooSmall);

                if (chunkID) {   /* note : chunk 0 is already written directly into dst */

                    if (!error) memcpy((char*)dst + dstPos, mtctx->jobs[chunkID].dstBuff.start, cSize);

                    ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->jobs[chunkID].dstBuff);

                    mtctx->jobs[chunkID].dstBuff = g_nullBuffer;

                }

                dstPos += cSize ;

            }

        }

        if (!error) DEBUGLOG(3, "compressed size : %u  ", (U32)dstPos);

        return error ? error : dstPos;

    }

}

/* ====================================== */

/* =======      Streaming API     ======= */

/* ====================================== */

static void ZSTDMT_waitForAllJobsCompleted(ZSTDMT_CCtx* zcs) {

    while (zcs->doneJobID < zcs->nextJobID) {

        unsigned const jobID = zcs->doneJobID & zcs->jobIDMask;

        PTHREAD_MUTEX_LOCK(&zcs->jobCompleted_mutex);

        while (zcs->jobs[jobID].jobCompleted==0) {

            DEBUGLOG(4, "waiting for jobCompleted signal from chunk %u", zcs->doneJobID);   /* we want to block when waiting for data to flush */

            pthread_cond_wait(&zcs->jobCompleted_cond, &zcs->jobCompleted_mutex);

        }

        pthread_mutex_unlock(&zcs->jobCompleted_mutex);

        zcs->doneJobID++;

    }

}

static size_t ZSTDMT_initCStream_internal(ZSTDMT_CCtx* zcs,

                                    const void* dict, size_t dictSize, unsigned updateDict,

                                    ZSTD_parameters params, unsigned long long pledgedSrcSize)

{

    ZSTD_customMem const cmem = { NULL, NULL, NULL };

    DEBUGLOG(3, "Started new compression, with windowLog : %u", params.cParams.windowLog);

    if (zcs->nbThreads==1) return ZSTD_initCStream_advanced(zcs->cstream, dict, dictSize, params, pledgedSrcSize);

    if (zcs->allJobsCompleted == 0) {   /* previous job not correctly finished */

        ZSTDMT_waitForAllJobsCompleted(zcs);

        ZSTDMT_releaseAllJobResources(zcs);

        zcs->allJobsCompleted = 1;

    }

    zcs->params = params;

    if (updateDict) {

        ZSTD_freeCDict(zcs->cdict); zcs->cdict = NULL;

        if (dict && dictSize) {

            zcs->cdict = ZSTD_createCDict_advanced(dict, dictSize, 0, params, cmem);

            if (zcs->cdict == NULL) return ERROR(memory_allocation);

    }   }

    zcs->frameContentSize = pledgedSrcSize;

    zcs->targetDictSize = (zcs->overlapRLog>=9) ? 0 : (size_t)1 << (zcs->params.cParams.windowLog - zcs->overlapRLog);

    DEBUGLOG(4, "overlapRLog : %u ", zcs->overlapRLog);

    DEBUGLOG(3, "overlap Size : %u KB", (U32)(zcs->targetDictSize>>10));

    zcs->targetSectionSize = zcs->sectionSize ? zcs->sectionSize : (size_t)1 << (zcs->params.cParams.windowLog + 2);

    zcs->targetSectionSize = MAX(ZSTDMT_SECTION_SIZE_MIN, zcs->targetSectionSize);

    zcs->targetSectionSize = MAX(zcs->targetDictSize, zcs->targetSectionSize);

    DEBUGLOG(3, "Section Size : %u KB", (U32)(zcs->targetSectionSize>>10));

    zcs->marginSize = zcs->targetSectionSize >> 2;

    zcs->inBuffSize = zcs->targetDictSize + zcs->targetSectionSize + zcs->marginSize;

    zcs->inBuff.buffer = ZSTDMT_getBuffer(zcs->buffPool, zcs->inBuffSize);

    if (zcs->inBuff.buffer.start == NULL) return ERROR(memory_allocation);

    zcs->inBuff.filled = 0;

    zcs->dictSize = 0;