blob: 8564bc439214df313b80684735aedf3d17022710 [file] [log] [blame]
/*
* 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).
*/
/* ====== Tuning parameters ====== */
#define ZSTDMT_NBTHREADS_MAX 256
#define ZSTDMT_OVERLAPLOG_DEFAULT 6
/* ====== Compiler specifics ====== */
#if defined(_MSC_VER)
# pragma warning(disable : 4204) /* disable: C4204: non-constant aggregate initializer */
#endif
/* ====== Dependencies ====== */
#include <string.h> /* memcpy, memset */
#include "pool.h" /* threadpool */
#include "threading.h" /* mutex */
#include "zstd_internal.h" /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */
#include "zstdmt_compress.h"
/* ====== Debug ====== */
#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=2)
# include <stdio.h>
# include <unistd.h>
# include <sys/times.h>
# define DEBUGLOGRAW(l, ...) if (l<=ZSTD_DEBUG) { fprintf(stderr, __VA_ARGS__); }
# 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(void)
{
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 6
#define PTHREAD_MUTEX_LOCK(mutex) { \
if (ZSTD_DEBUG>=MUTEX_WAIT_TIME_DLEVEL) { \
unsigned long long const beforeTime = GetCurrentClockTimeMicroseconds(); \
pthread_mutex_lock(mutex); \
{ unsigned long long const afterTime = GetCurrentClockTimeMicroseconds(); \
unsigned long long const 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 PTHREAD_MUTEX_LOCK(m) pthread_mutex_lock(m)
# define DEBUG_PRINTHEX(l,p,n) {}
#endif
/* ===== Buffer Pool ===== */
/* a single Buffer Pool can be invoked from multiple threads in parallel */
typedef struct buffer_s {
void* start;
size_t size;
} buffer_t;
static const buffer_t g_nullBuffer = { NULL, 0 };
typedef struct ZSTDMT_bufferPool_s {
pthread_mutex_t poolMutex;
size_t bufferSize;
unsigned totalBuffers;
unsigned nbBuffers;
ZSTD_customMem cMem;
buffer_t bTable[1]; /* variable size */
} ZSTDMT_bufferPool;
static ZSTDMT_bufferPool* ZSTDMT_createBufferPool(unsigned nbThreads, ZSTD_customMem cMem)
{
unsigned const maxNbBuffers = 2*nbThreads + 3;
ZSTDMT_bufferPool* const bufPool = (ZSTDMT_bufferPool*)ZSTD_calloc(
sizeof(ZSTDMT_bufferPool) + (maxNbBuffers-1) * sizeof(buffer_t), cMem);
if (bufPool==NULL) return NULL;
if (pthread_mutex_init(&bufPool->poolMutex, NULL)) {
ZSTD_free(bufPool, cMem);
return NULL;
}
bufPool->bufferSize = 64 KB;
bufPool->totalBuffers = maxNbBuffers;
bufPool->nbBuffers = 0;
bufPool->cMem = cMem;
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++)
ZSTD_free(bufPool->bTable[u].start, bufPool->cMem);
pthread_mutex_destroy(&bufPool->poolMutex);
ZSTD_free(bufPool, bufPool->cMem);
}
/* only works at initialization, not during compression */
static size_t ZSTDMT_sizeof_bufferPool(ZSTDMT_bufferPool* bufPool)
{
size_t const poolSize = sizeof(*bufPool)
+ (bufPool->totalBuffers - 1) * sizeof(buffer_t);
unsigned u;
size_t totalBufferSize = 0;
pthread_mutex_lock(&bufPool->poolMutex);
for (u=0; u<bufPool->totalBuffers; u++)
totalBufferSize += bufPool->bTable[u].size;
pthread_mutex_unlock(&bufPool->poolMutex);
return poolSize + totalBufferSize;
}
static void ZSTDMT_setBufferSize(ZSTDMT_bufferPool* bufPool, size_t bSize)
{
bufPool->bufferSize = bSize;
}
/** ZSTDMT_getBuffer() :
* assumption : bufPool must be valid */
static buffer_t ZSTDMT_getBuffer(ZSTDMT_bufferPool* bufPool)
{
size_t const bSize = bufPool->bufferSize;
DEBUGLOG(5, "ZSTDMT_getBuffer");
pthread_mutex_lock(&bufPool->poolMutex);
if (bufPool->nbBuffers) { /* try to use an existing buffer */
buffer_t const buf = bufPool->bTable[--(bufPool->nbBuffers)];
size_t const availBufferSize = buf.size;
if ((availBufferSize >= bSize) & (availBufferSize <= 10*bSize)) {
/* large enough, but not too much */
pthread_mutex_unlock(&bufPool->poolMutex);
return buf;
}
/* size conditions not respected : scratch this buffer, create new one */
DEBUGLOG(5, "existing buffer does not meet size conditions => freeing");
ZSTD_free(buf.start, bufPool->cMem);
}
pthread_mutex_unlock(&bufPool->poolMutex);
/* create new buffer */
DEBUGLOG(5, "create a new buffer");
{ buffer_t buffer;
void* const start = ZSTD_malloc(bSize, bufPool->cMem);
buffer.start = start; /* note : start can be NULL if malloc fails ! */
buffer.size = (start==NULL) ? 0 : bSize;
return buffer;
}
}
/* store buffer for later re-use, up to pool capacity */
static void ZSTDMT_releaseBuffer(ZSTDMT_bufferPool* bufPool, buffer_t buf)
{
if (buf.start == NULL) return; /* compatible with release on NULL */
DEBUGLOG(5, "ZSTDMT_releaseBuffer");
pthread_mutex_lock(&bufPool->poolMutex);
if (bufPool->nbBuffers < bufPool->totalBuffers) {
bufPool->bTable[bufPool->nbBuffers++] = buf; /* stored for later use */
pthread_mutex_unlock(&bufPool->poolMutex);
return;
}
pthread_mutex_unlock(&bufPool->poolMutex);
/* Reached bufferPool capacity (should not happen) */
DEBUGLOG(5, "buffer pool capacity reached => freeing ");
ZSTD_free(buf.start, bufPool->cMem);
}
/* ===== CCtx Pool ===== */
/* a single CCtx Pool can be invoked from multiple threads in parallel */
typedef struct {
pthread_mutex_t poolMutex;
unsigned totalCCtx;
unsigned availCCtx;
ZSTD_customMem cMem;
ZSTD_CCtx* cctx[1]; /* variable size */
} ZSTDMT_CCtxPool;
/* 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 */
pthread_mutex_destroy(&pool->poolMutex);
ZSTD_free(pool, pool->cMem);
}
/* ZSTDMT_createCCtxPool() :
* implies nbThreads >= 1 , checked by caller ZSTDMT_createCCtx() */
static ZSTDMT_CCtxPool* ZSTDMT_createCCtxPool(unsigned nbThreads,
ZSTD_customMem cMem)
{
ZSTDMT_CCtxPool* const cctxPool = (ZSTDMT_CCtxPool*) ZSTD_calloc(
sizeof(ZSTDMT_CCtxPool) + (nbThreads-1)*sizeof(ZSTD_CCtx*), cMem);
if (!cctxPool) return NULL;
if (pthread_mutex_init(&cctxPool->poolMutex, NULL)) {
ZSTD_free(cctxPool, cMem);
return NULL;
}
cctxPool->cMem = cMem;
cctxPool->totalCCtx = nbThreads;
cctxPool->availCCtx = 1; /* at least one cctx for single-thread mode */
cctxPool->cctx[0] = ZSTD_createCCtx_advanced(cMem);
if (!cctxPool->cctx[0]) { ZSTDMT_freeCCtxPool(cctxPool); return NULL; }
DEBUGLOG(3, "cctxPool created, with %u threads", nbThreads);
return cctxPool;
}
/* only works during initialization phase, not during compression */
static size_t ZSTDMT_sizeof_CCtxPool(ZSTDMT_CCtxPool* cctxPool)
{
pthread_mutex_lock(&cctxPool->poolMutex);
{ unsigned const nbThreads = cctxPool->totalCCtx;
size_t const poolSize = sizeof(*cctxPool)
+ (nbThreads-1)*sizeof(ZSTD_CCtx*);
unsigned u;
size_t totalCCtxSize = 0;
for (u=0; u<nbThreads; u++) {
totalCCtxSize += ZSTD_sizeof_CCtx(cctxPool->cctx[u]);
}
pthread_mutex_unlock(&cctxPool->poolMutex);
return poolSize + totalCCtxSize;
}
}
static ZSTD_CCtx* ZSTDMT_getCCtx(ZSTDMT_CCtxPool* cctxPool)
{
DEBUGLOG(5, "ZSTDMT_getCCtx");
pthread_mutex_lock(&cctxPool->poolMutex);
if (cctxPool->availCCtx) {
cctxPool->availCCtx--;
{ ZSTD_CCtx* const cctx = cctxPool->cctx[cctxPool->availCCtx];
pthread_mutex_unlock(&cctxPool->poolMutex);
return cctx;
} }
pthread_mutex_unlock(&cctxPool->poolMutex);
DEBUGLOG(5, "create one more CCtx");
return ZSTD_createCCtx_advanced(cctxPool->cMem); /* 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 */
pthread_mutex_lock(&pool->poolMutex);
if (pool->availCCtx < pool->totalCCtx)
pool->cctx[pool->availCCtx++] = cctx;
else {
/* pool overflow : should not happen, since totalCCtx==nbThreads */
DEBUGLOG(5, "CCtx pool overflow : free cctx");
ZSTD_freeCCtx(cctx);
}
pthread_mutex_unlock(&pool->poolMutex);
}
/* ===== Thread worker ===== */
typedef struct {
buffer_t src;
const void* srcStart;
size_t dictSize;
size_t srcSize;
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;
const ZSTD_CDict* cdict;
ZSTDMT_CCtxPool* cctxPool;
ZSTDMT_bufferPool* bufPool;
unsigned long long fullFrameSize;
} ZSTDMT_jobDescription;
/* ZSTDMT_compressChunk() : POOL_function type */
void ZSTDMT_compressChunk(void* jobDescription)
{
ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)jobDescription;
ZSTD_CCtx* cctx = ZSTDMT_getCCtx(job->cctxPool);
const void* const src = (const char*)job->srcStart + job->dictSize;
buffer_t dstBuff = job->dstBuff;
DEBUGLOG(5, "job (first:%u) (last:%u) : dictSize %u, srcSize %u",
job->firstChunk, job->lastChunk, (U32)job->dictSize, (U32)job->srcSize);
if (cctx==NULL) {
job->cSize = ERROR(memory_allocation);
goto _endJob;
}
if (dstBuff.start == NULL) {
dstBuff = ZSTDMT_getBuffer(job->bufPool);
if (dstBuff.start==NULL) {
job->cSize = ERROR(memory_allocation);
goto _endJob;
}
job->dstBuff = dstBuff;
}
if (job->cdict) { /* should only happen for first segment */
size_t const initError = ZSTD_compressBegin_usingCDict_advanced(cctx, job->cdict, job->params.fParams, job->fullFrameSize);
DEBUGLOG(5, "using CDict");
if (ZSTD_isError(initError)) { job->cSize = initError; goto _endJob; }
} else { /* srcStart points at reloaded section */
if (!job->firstChunk) job->params.fParams.contentSizeFlag = 0; /* ensure no srcSize control */
{ size_t const dictModeError = ZSTD_setCCtxParameter(cctx, ZSTD_p_forceRawDict, 1); /* Force loading dictionary in "content-only" mode (no header analysis) */
size_t const initError = ZSTD_compressBegin_advanced(cctx, job->srcStart, job->dictSize, job->params, job->fullFrameSize);
if (ZSTD_isError(initError) || ZSTD_isError(dictModeError)) { job->cSize = initError; goto _endJob; }
ZSTD_setCCtxParameter(cctx, ZSTD_p_forceWindow, 1);
} }
if (!job->firstChunk) { /* flush and overwrite frame header when it's not first segment */
size_t const hSize = ZSTD_compressContinue(cctx, dstBuff.start, dstBuff.size, src, 0);
if (ZSTD_isError(hSize)) { job->cSize = hSize; goto _endJob; }
ZSTD_invalidateRepCodes(cctx);
}
DEBUGLOG(5, "Compressing : ");
DEBUG_PRINTHEX(4, job->srcStart, 12);
job->cSize = (job->lastChunk) ?
ZSTD_compressEnd (cctx, dstBuff.start, dstBuff.size, src, job->srcSize) :
ZSTD_compressContinue(cctx, dstBuff.start, dstBuff.size, src, job->srcSize);
DEBUGLOG(5, "compressed %u bytes into %u bytes (first:%u) (last:%u)",
(unsigned)job->srcSize, (unsigned)job->cSize, job->firstChunk, job->lastChunk);
DEBUGLOG(5, "dstBuff.size : %u ; => %s", (U32)dstBuff.size, ZSTD_getErrorName(job->cSize));
_endJob:
ZSTDMT_releaseCCtx(job->cctxPool, cctx);
ZSTDMT_releaseBuffer(job->bufPool, job->src);
job->src = g_nullBuffer; job->srcStart = NULL;
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 ===== */
/* ------------------------------------------ */
typedef struct {
buffer_t buffer;
size_t filled;
} inBuff_t;
struct ZSTDMT_CCtx_s {
POOL_ctx* factory;
ZSTDMT_jobDescription* jobs;
ZSTDMT_bufferPool* bufPool;
ZSTDMT_CCtxPool* cctxPool;
pthread_mutex_t jobCompleted_mutex;
pthread_cond_t jobCompleted_cond;
size_t targetSectionSize;
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 overlapLog;
unsigned long long frameContentSize;
size_t sectionSize;
ZSTD_customMem cMem;
ZSTD_CDict* cdictLocal;
const ZSTD_CDict* cdict;
};
static ZSTDMT_jobDescription* ZSTDMT_allocJobsTable(U32* nbJobsPtr, ZSTD_customMem cMem)
{
U32 const nbJobsLog2 = ZSTD_highbit32(*nbJobsPtr) + 1;
U32 const nbJobs = 1 << nbJobsLog2;
*nbJobsPtr = nbJobs;
return (ZSTDMT_jobDescription*) ZSTD_calloc(
nbJobs * sizeof(ZSTDMT_jobDescription), cMem);
}
ZSTDMT_CCtx* ZSTDMT_createCCtx_advanced(unsigned nbThreads, ZSTD_customMem cMem)
{
ZSTDMT_CCtx* mtctx;
U32 nbJobs = nbThreads + 2;
DEBUGLOG(3, "ZSTDMT_createCCtx_advanced");
if (nbThreads < 1) return NULL;
nbThreads = MIN(nbThreads , ZSTDMT_NBTHREADS_MAX);
if ((cMem.customAlloc!=NULL) ^ (cMem.customFree!=NULL))
/* invalid custom allocator */
return NULL;
mtctx = (ZSTDMT_CCtx*) ZSTD_calloc(sizeof(ZSTDMT_CCtx), cMem);
if (!mtctx) return NULL;
mtctx->cMem = cMem;
mtctx->nbThreads = nbThreads;
mtctx->allJobsCompleted = 1;
mtctx->sectionSize = 0;
mtctx->overlapLog = ZSTDMT_OVERLAPLOG_DEFAULT;
mtctx->factory = POOL_create(nbThreads, 0);
mtctx->jobs = ZSTDMT_allocJobsTable(&nbJobs, cMem);
mtctx->jobIDMask = nbJobs - 1;
mtctx->bufPool = ZSTDMT_createBufferPool(nbThreads, cMem);
mtctx->cctxPool = ZSTDMT_createCCtxPool(nbThreads, cMem);
if (!mtctx->factory | !mtctx->jobs | !mtctx->bufPool | !mtctx->cctxPool) {
ZSTDMT_freeCCtx(mtctx);
return NULL;
}
if (pthread_mutex_init(&mtctx->jobCompleted_mutex, NULL)) {
ZSTDMT_freeCCtx(mtctx);
return NULL;
}
if (pthread_cond_init(&mtctx->jobCompleted_cond, NULL)) {
ZSTDMT_freeCCtx(mtctx);
return NULL;
}
DEBUGLOG(3, "mt_cctx created, for %u threads", nbThreads);
return mtctx;
}
ZSTDMT_CCtx* ZSTDMT_createCCtx(unsigned nbThreads)
{
return ZSTDMT_createCCtx_advanced(nbThreads, ZSTD_defaultCMem);
}
/* ZSTDMT_releaseAllJobResources() :
* note : ensure all workers are killed first ! */
static void ZSTDMT_releaseAllJobResources(ZSTDMT_CCtx* mtctx)
{
unsigned jobID;
DEBUGLOG(3, "ZSTDMT_releaseAllJobResources");
for (jobID=0; jobID <= mtctx->jobIDMask; jobID++) {
ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[jobID].dstBuff);
mtctx->jobs[jobID].dstBuff = g_nullBuffer;
ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[jobID].src);
mtctx->jobs[jobID].src = g_nullBuffer;
}
memset(mtctx->jobs, 0, (mtctx->jobIDMask+1)*sizeof(ZSTDMT_jobDescription));
ZSTDMT_releaseBuffer(mtctx->bufPool, 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->bufPool); /* release job resources into pools first */
ZSTD_free(mtctx->jobs, mtctx->cMem);
ZSTDMT_freeCCtxPool(mtctx->cctxPool);
ZSTD_freeCDict(mtctx->cdictLocal);
pthread_mutex_destroy(&mtctx->jobCompleted_mutex);
pthread_cond_destroy(&mtctx->jobCompleted_cond);
ZSTD_free(mtctx, mtctx->cMem);
return 0;
}
size_t ZSTDMT_sizeof_CCtx(ZSTDMT_CCtx* mtctx)
{
if (mtctx == NULL) return 0; /* supports sizeof NULL */
return sizeof(*mtctx)
+ POOL_sizeof(mtctx->factory)
+ ZSTDMT_sizeof_bufferPool(mtctx->bufPool)
+ (mtctx->jobIDMask+1) * sizeof(ZSTDMT_jobDescription)
+ ZSTDMT_sizeof_CCtxPool(mtctx->cctxPool)
+ ZSTD_sizeof_CDict(mtctx->cdictLocal);
}
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(5, "ZSTDMT_p_overlapSectionLog : %u", value);
mtctx->overlapLog = (value >= 9) ? 9 : value;
return 0;
default :
return ERROR(parameter_unsupported);
}
}
/* ------------------------------------------ */
/* ===== Multi-threaded compression ===== */
/* ------------------------------------------ */
static unsigned computeNbChunks(size_t srcSize, unsigned windowLog, unsigned nbThreads) {
size_t const chunkSizeTarget = (size_t)1 << (windowLog + 2);
size_t const chunkMaxSize = chunkSizeTarget << 2;
size_t const passSizeMax = chunkMaxSize * nbThreads;
unsigned const multiplier = (unsigned)(srcSize / passSizeMax) + 1;
unsigned const nbChunksLarge = multiplier * nbThreads;
unsigned const nbChunksMax = (unsigned)(srcSize / chunkSizeTarget) + 1;
unsigned const nbChunksSmall = MIN(nbChunksMax, nbThreads);
return (multiplier>1) ? nbChunksLarge : nbChunksSmall;
}
size_t ZSTDMT_compress_advanced(ZSTDMT_CCtx* mtctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const ZSTD_CDict* cdict,
ZSTD_parameters const params,
unsigned overlapLog)
{
unsigned const overlapRLog = (overlapLog>9) ? 0 : 9-overlapLog;
size_t const overlapSize = (overlapRLog>=9) ? 0 : (size_t)1 << (params.cParams.windowLog - overlapRLog);
unsigned nbChunks = computeNbChunks(srcSize, params.cParams.windowLog, mtctx->nbThreads);
size_t const proposedChunkSize = (srcSize + (nbChunks-1)) / nbChunks;
size_t const avgChunkSize = ((proposedChunkSize & 0x1FFFF) < 0x7FFF) ? proposedChunkSize + 0xFFFF : proposedChunkSize; /* avoid too small last block */
const char* const srcStart = (const char*)src;
size_t remainingSrcSize = srcSize;
unsigned const compressWithinDst = (dstCapacity >= ZSTD_compressBound(srcSize)) ? nbChunks : (unsigned)(dstCapacity / ZSTD_compressBound(avgChunkSize)); /* presumes avgChunkSize >= 256 KB, which should be the case */
size_t frameStartPos = 0, dstBufferPos = 0;
XXH64_state_t xxh64;
DEBUGLOG(4, "nbChunks : %2u (chunkSize : %u bytes) ", nbChunks, (U32)avgChunkSize);
if (nbChunks==1) { /* fallback to single-thread mode */
ZSTD_CCtx* const cctx = mtctx->cctxPool->cctx[0];
if (cdict) return ZSTD_compress_usingCDict_advanced(cctx, dst, dstCapacity, src, srcSize, cdict, params.fParams);
return ZSTD_compress_advanced(cctx, dst, dstCapacity, src, srcSize, NULL, 0, params);
}
assert(avgChunkSize >= 256 KB); /* condition for ZSTD_compressBound(A) + ZSTD_compressBound(B) <= ZSTD_compressBound(A+B), which is required for compressWithinDst */
ZSTDMT_setBufferSize(mtctx->bufPool, ZSTD_compressBound(avgChunkSize) );
XXH64_reset(&xxh64, 0);
if (nbChunks > mtctx->jobIDMask+1) { /* enlarge job table */
U32 nbJobs = nbChunks;
ZSTD_free(mtctx->jobs, mtctx->cMem);
mtctx->jobIDMask = 0;
mtctx->jobs = ZSTDMT_allocJobsTable(&nbJobs, mtctx->cMem);
if (mtctx->jobs==NULL) return ERROR(memory_allocation);
mtctx->jobIDMask = nbJobs - 1;
}
{ unsigned u;
for (u=0; u<nbChunks; u++) {
size_t const chunkSize = MIN(remainingSrcSize, avgChunkSize);
size_t const dstBufferCapacity = ZSTD_compressBound(chunkSize);
buffer_t const dstAsBuffer = { (char*)dst + dstBufferPos, dstBufferCapacity };
buffer_t const dstBuffer = u < compressWithinDst ? dstAsBuffer : g_nullBuffer;
size_t dictSize = u ? overlapSize : 0;
mtctx->jobs[u].src = g_nullBuffer;
mtctx->jobs[u].srcStart = srcStart + frameStartPos - dictSize;
mtctx->jobs[u].dictSize = dictSize;
mtctx->jobs[u].srcSize = chunkSize;
mtctx->jobs[u].cdict = mtctx->nextJobID==0 ? cdict : NULL;
mtctx->jobs[u].fullFrameSize = srcSize;
mtctx->jobs[u].params = params;
/* do not calculate checksum within sections, but write it in header for first section */
if (u!=0) mtctx->jobs[u].params.fParams.checksumFlag = 0;
mtctx->jobs[u].dstBuff = dstBuffer;
mtctx->jobs[u].cctxPool = mtctx->cctxPool;
mtctx->jobs[u].bufPool = mtctx->bufPool;
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;
if (params.fParams.checksumFlag) {
XXH64_update(&xxh64, srcStart + frameStartPos, chunkSize);
}
DEBUGLOG(5, "posting job %u (%u bytes)", u, (U32)chunkSize);
DEBUG_PRINTHEX(6, mtctx->jobs[u].srcStart, 12);
POOL_add(mtctx->factory, ZSTDMT_compressChunk, &mtctx->jobs[u]);
frameStartPos += chunkSize;
dstBufferPos += dstBufferCapacity;
remainingSrcSize -= chunkSize;
} }
/* collect result */
{ size_t error = 0, dstPos = 0;
unsigned chunkID;
for (chunkID=0; chunkID<nbChunks; chunkID++) {
DEBUGLOG(5, "waiting for chunk %u ", chunkID);
PTHREAD_MUTEX_LOCK(&mtctx->jobCompleted_mutex);
while (mtctx->jobs[chunkID].jobCompleted==0) {
DEBUGLOG(5, "waiting for jobCompleted signal from chunk %u", chunkID);
pthread_cond_wait(&mtctx->jobCompleted_cond, &mtctx->jobCompleted_mutex);
}
pthread_mutex_unlock(&mtctx->jobCompleted_mutex);
DEBUGLOG(5, "ready to write chunk %u ", chunkID);
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 written directly at dst, which is correct position */
if (!error)
memmove((char*)dst + dstPos, mtctx->jobs[chunkID].dstBuff.start, cSize); /* may overlap when chunk compressed within dst */
if (chunkID >= compressWithinDst) { /* chunk compressed into its own buffer, which must be released */
DEBUGLOG(5, "releasing buffer %u>=%u", chunkID, compressWithinDst);
ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[chunkID].dstBuff);
}
mtctx->jobs[chunkID].dstBuff = g_nullBuffer;
}
dstPos += cSize ;
}
} /* for (chunkID=0; chunkID<nbChunks; chunkID++) */
DEBUGLOG(4, "checksumFlag : %u ", params.fParams.checksumFlag);
if (params.fParams.checksumFlag) {
U32 const checksum = (U32)XXH64_digest(&xxh64);
if (dstPos + 4 > dstCapacity) {
error = ERROR(dstSize_tooSmall);
} else {
DEBUGLOG(4, "writing checksum : %08X \n", checksum);
MEM_writeLE32((char*)dst + dstPos, checksum);
dstPos += 4;
} }
if (!error) DEBUGLOG(4, "compressed size : %u ", (U32)dstPos);
return error ? error : dstPos;
}
}
size_t ZSTDMT_compressCCtx(ZSTDMT_CCtx* mtctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
int compressionLevel)
{
U32 const overlapLog = (compressionLevel >= ZSTD_maxCLevel()) ? 9 : ZSTDMT_OVERLAPLOG_DEFAULT;
ZSTD_parameters params = ZSTD_getParams(compressionLevel, srcSize, 0);
params.fParams.contentSizeFlag = 1;
return ZSTDMT_compress_advanced(mtctx, dst, dstCapacity, src, srcSize, NULL, params, overlapLog);
}
/* ====================================== */
/* ======= Streaming API ======= */
/* ====================================== */
static void ZSTDMT_waitForAllJobsCompleted(ZSTDMT_CCtx* zcs)
{
DEBUGLOG(4, "ZSTDMT_waitForAllJobsCompleted");
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(5, "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++;
}
}
/** ZSTDMT_initCStream_internal() :
* internal usage only */
size_t ZSTDMT_initCStream_internal(ZSTDMT_CCtx* zcs,
const void* dict, size_t dictSize, const ZSTD_CDict* cdict,
ZSTD_parameters params, unsigned long long pledgedSrcSize)
{
DEBUGLOG(4, "ZSTDMT_initCStream_internal");
/* params are supposed to be fully validated at this point */
assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
assert(!((dict) && (cdict))); /* either dict or cdict, not both */
if (zcs->nbThreads==1) {
DEBUGLOG(4, "single thread mode");
return ZSTD_initCStream_internal(zcs->cctxPool->cctx[0],
dict, dictSize, cdict,
params, pledgedSrcSize);
}
if (zcs->allJobsCompleted == 0) { /* previous compression not correctly finished */
ZSTDMT_waitForAllJobsCompleted(zcs);
ZSTDMT_releaseAllJobResources(zcs);
zcs->allJobsCompleted = 1;
}
zcs->params = params;
zcs->frameContentSize = pledgedSrcSize;
if (dict) {
DEBUGLOG(4,"cdictLocal: %08X", (U32)(size_t)zcs->cdictLocal);
ZSTD_freeCDict(zcs->cdictLocal);
zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize,
0 /* byRef */, ZSTD_dm_auto, /* note : a loadPrefix becomes an internal CDict */
params.cParams, zcs->cMem);
zcs->cdict = zcs->cdictLocal;
if (zcs->cdictLocal == NULL) return ERROR(memory_allocation);
} else {
DEBUGLOG(4,"cdictLocal: %08X", (U32)(size_t)zcs->cdictLocal);
ZSTD_freeCDict(zcs->cdictLocal);
zcs->cdictLocal = NULL;
zcs->cdict = cdict;
}
zcs->targetDictSize = (zcs->overlapLog==0) ? 0 : (size_t)1 << (zcs->params.cParams.windowLog - (9 - zcs->overlapLog));
DEBUGLOG(4, "overlapLog : %u ", zcs->overlapLog);
DEBUGLOG(4, "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(4, "Section Size : %u KB", (U32)(zcs->targetSectionSize>>10));
zcs->inBuffSize = zcs->targetDictSize + zcs->targetSectionSize;
ZSTDMT_setBufferSize(zcs->bufPool, MAX(zcs->inBuffSize, ZSTD_compressBound(zcs->targetSectionSize)) );
zcs->inBuff.buffer = g_nullBuffer;
zcs->dictSize = 0;
zcs->doneJobID = 0;
zcs->nextJobID = 0;
zcs->frameEnded = 0;
zcs->allJobsCompleted = 0;
if (params.fParams.checksumFlag) XXH64_reset(&zcs->xxhState, 0);
return 0;
}
size_t ZSTDMT_initCStream_advanced(ZSTDMT_CCtx* mtctx,
const void* dict, size_t dictSize,
ZSTD_parameters params,
unsigned long long pledgedSrcSize)
{
DEBUGLOG(5, "ZSTDMT_initCStream_advanced");
return ZSTDMT_initCStream_internal(mtctx, dict, dictSize, NULL, params, pledgedSrcSize);
}
size_t ZSTDMT_initCStream_usingCDict(ZSTDMT_CCtx* mtctx,
const ZSTD_CDict* cdict,
ZSTD_frameParameters fParams,
unsigned long long pledgedSrcSize)
{
ZSTD_parameters params = ZSTD_getParamsFromCDict(cdict);
if (cdict==NULL) return ERROR(dictionary_wrong); /* method incompatible with NULL cdict */
params.fParams = fParams;
return ZSTDMT_initCStream_internal(mtctx, NULL, 0 /*dictSize*/, cdict,
params, pledgedSrcSize);
}
/* ZSTDMT_resetCStream() :
* pledgedSrcSize is optional and can be zero == unknown */
size_t ZSTDMT_resetCStream(ZSTDMT_CCtx* zcs, unsigned long long pledgedSrcSize)
{
if (zcs->nbThreads==1)
return ZSTD_resetCStream(zcs->cctxPool->cctx[0], pledgedSrcSize);
return ZSTDMT_initCStream_internal(zcs, NULL, 0, 0, zcs->params, pledgedSrcSize);
}
size_t ZSTDMT_initCStream(ZSTDMT_CCtx* zcs, int compressionLevel) {
ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, 0);
return ZSTDMT_initCStream_internal(zcs, NULL, 0, NULL, params, 0);
}
static size_t ZSTDMT_createCompressionJob(ZSTDMT_CCtx* zcs, size_t srcSize, unsigned endFrame)
{
unsigned const jobID = zcs->nextJobID & zcs->jobIDMask;
DEBUGLOG(4, "preparing job %u to compress %u bytes with %u preload ",
zcs->nextJobID, (U32)srcSize, (U32)zcs->dictSize);
zcs->jobs[jobID].src = zcs->inBuff.buffer;
zcs->jobs[jobID].srcStart = zcs->inBuff.buffer.start;
zcs->jobs[jobID].srcSize = srcSize;
zcs->jobs[jobID].dictSize = zcs->dictSize;
assert(zcs->inBuff.filled >= srcSize + zcs->dictSize);
zcs->jobs[jobID].params = zcs->params;
/* do not calculate checksum within sections, but write it in header for first section */
if (zcs->nextJobID) zcs->jobs[jobID].params.fParams.checksumFlag = 0;
zcs->jobs[jobID].cdict = zcs->nextJobID==0 ? zcs->cdict : NULL;
zcs->jobs[jobID].fullFrameSize = zcs->frameContentSize;
zcs->jobs[jobID].dstBuff = g_nullBuffer;
zcs->jobs[jobID].cctxPool = zcs->cctxPool;
zcs->jobs[jobID].bufPool = zcs->bufPool;
zcs->jobs[jobID].firstChunk = (zcs->nextJobID==0);
zcs->jobs[jobID].lastChunk = endFrame;
zcs->jobs[jobID].jobCompleted = 0;
zcs->jobs[jobID].dstFlushed = 0;
zcs->jobs[jobID].jobCompleted_mutex = &zcs->jobCompleted_mutex;
zcs->jobs[jobID].jobCompleted_cond = &zcs->jobCompleted_cond;
if (zcs->params.fParams.checksumFlag)
XXH64_update(&zcs->xxhState, (const char*)zcs->inBuff.buffer.start + zcs->dictSize, srcSize);
/* get a new buffer for next input */
if (!endFrame) {
size_t const newDictSize = MIN(srcSize + zcs->dictSize, zcs->targetDictSize);
zcs->inBuff.buffer = ZSTDMT_getBuffer(zcs->bufPool);
if (zcs->inBuff.buffer.start == NULL) { /* not enough memory to allocate next input buffer */
zcs->jobs[jobID].jobCompleted = 1;
zcs->nextJobID++;
ZSTDMT_waitForAllJobsCompleted(zcs);
ZSTDMT_releaseAllJobResources(zcs);
return ERROR(memory_allocation);
}
zcs->inBuff.filled -= srcSize + zcs->dictSize - newDictSize;
memmove(zcs->inBuff.buffer.start,
(const char*)zcs->jobs[jobID].srcStart + zcs->dictSize + srcSize - newDictSize,
zcs->inBuff.filled);
zcs->dictSize = newDictSize;
} else { /* if (endFrame==1) */
zcs->inBuff.buffer = g_nullBuffer;
zcs->inBuff.filled = 0;
zcs->dictSize = 0;
zcs->frameEnded = 1;
if (zcs->nextJobID == 0) {
/* single chunk exception : checksum is calculated directly within worker thread */
zcs->params.fParams.checksumFlag = 0;
} }
DEBUGLOG(4, "posting job %u : %u bytes (end:%u) (note : doneJob = %u=>%u)",
zcs->nextJobID,
(U32)zcs->jobs[jobID].srcSize,
zcs->jobs[jobID].lastChunk,
zcs->doneJobID,
zcs->doneJobID & zcs->jobIDMask);
POOL_add(zcs->factory, ZSTDMT_compressChunk, &zcs->jobs[jobID]); /* this call is blocking when thread worker pool is exhausted */
zcs->nextJobID++;
return 0;
}
/* ZSTDMT_flushNextJob() :
* output : will be updated with amount of data flushed .
* blockToFlush : if >0, the function will block and wait if there is no data available to flush .
* @return : amount of data remaining within internal buffer, 1 if unknown but > 0, 0 if no more, or an error code */
static size_t ZSTDMT_flushNextJob(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output, unsigned blockToFlush)
{
unsigned const wJobID = zcs->doneJobID & zcs->jobIDMask;
if (zcs->doneJobID == zcs->nextJobID) return 0; /* all flushed ! */
PTHREAD_MUTEX_LOCK(&zcs->jobCompleted_mutex);
while (zcs->jobs[wJobID].jobCompleted==0) {
DEBUGLOG(5, "waiting for jobCompleted signal from job %u", zcs->doneJobID);
if (!blockToFlush) { pthread_mutex_unlock(&zcs->jobCompleted_mutex); return 0; } /* nothing ready to be flushed => skip */
pthread_cond_wait(&zcs->jobCompleted_cond, &zcs->jobCompleted_mutex); /* block when nothing available to flush */
}
pthread_mutex_unlock(&zcs->jobCompleted_mutex);
/* compression job completed : output can be flushed */
{ ZSTDMT_jobDescription job = zcs->jobs[wJobID];
if (!job.jobScanned) {
if (ZSTD_isError(job.cSize)) {
DEBUGLOG(5, "compression error detected ");
ZSTDMT_waitForAllJobsCompleted(zcs);
ZSTDMT_releaseAllJobResources(zcs);
return job.cSize;
}
DEBUGLOG(5, "zcs->params.fParams.checksumFlag : %u ", zcs->params.fParams.checksumFlag);
if (zcs->params.fParams.checksumFlag) {
if (zcs->frameEnded && (zcs->doneJobID+1 == zcs->nextJobID)) { /* write checksum at end of last section */
U32 const checksum = (U32)XXH64_digest(&zcs->xxhState);
DEBUGLOG(5, "writing checksum : %08X \n", checksum);
MEM_writeLE32((char*)job.dstBuff.start + job.cSize, checksum);
job.cSize += 4;
zcs->jobs[wJobID].cSize += 4;
} }
zcs->jobs[wJobID].jobScanned = 1;
}
{ size_t const toWrite = MIN(job.cSize - job.dstFlushed, output->size - output->pos);
DEBUGLOG(5, "Flushing %u bytes from job %u ", (U32)toWrite, zcs->doneJobID);
memcpy((char*)output->dst + output->pos, (const char*)job.dstBuff.start + job.dstFlushed, toWrite);
output->pos += toWrite;
job.dstFlushed += toWrite;
}
if (job.dstFlushed == job.cSize) { /* output buffer fully flushed => move to next one */
ZSTDMT_releaseBuffer(zcs->bufPool, job.dstBuff);
zcs->jobs[wJobID].dstBuff = g_nullBuffer;
zcs->jobs[wJobID].jobCompleted = 0;
zcs->doneJobID++;
} else {
zcs->jobs[wJobID].dstFlushed = job.dstFlushed;
}
/* return value : how many bytes left in buffer ; fake it to 1 if unknown but >0 */
if (job.cSize > job.dstFlushed) return (job.cSize - job.dstFlushed);
if (zcs->doneJobID < zcs->nextJobID) return 1; /* still some buffer to flush */
zcs->allJobsCompleted = zcs->frameEnded; /* frame completed and entirely flushed */
return 0; /* everything flushed */
} }
/** ZSTDMT_compressStream_generic() :
* internal use only
* assumption : output and input are valid (pos <= size)
* @return : minimum amount of data remaining to flush, 0 if none */
size_t ZSTDMT_compressStream_generic(ZSTDMT_CCtx* mtctx,
ZSTD_outBuffer* output,
ZSTD_inBuffer* input,
ZSTD_EndDirective endOp)
{
size_t const newJobThreshold = mtctx->dictSize + mtctx->targetSectionSize;
assert(output->pos <= output->size);
assert(input->pos <= input->size);
if ((mtctx->frameEnded) && (endOp==ZSTD_e_continue)) {
/* current frame being ended. Only flush/end are allowed. Or start new frame with init */
return ERROR(stage_wrong);
}
if (mtctx->nbThreads==1) { /* delegate to single-thread (synchronous) */
return ZSTD_compressStream_generic(mtctx->cctxPool->cctx[0], output, input, endOp);
}
/* single-pass shortcut (note : this is synchronous-mode) */
if ( (mtctx->nextJobID==0) /* just started */
&& (mtctx->inBuff.filled==0) /* nothing buffered */
&& (endOp==ZSTD_e_end) /* end order */
&& (output->size - output->pos >= ZSTD_compressBound(input->size - input->pos)) ) { /* enough room */
size_t const cSize = ZSTDMT_compress_advanced(mtctx,
(char*)output->dst + output->pos, output->size - output->pos,
(const char*)input->src + input->pos, input->size - input->pos,
mtctx->cdict, mtctx->params, mtctx->overlapLog);
if (ZSTD_isError(cSize)) return cSize;
input->pos = input->size;
output->pos += cSize;
ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->inBuff.buffer); /* was allocated in initStream */
mtctx->allJobsCompleted = 1;
mtctx->frameEnded = 1;
return 0;
}
/* fill input buffer */
if (input->size > input->pos) { /* support NULL input */
if (mtctx->inBuff.buffer.start == NULL) {
mtctx->inBuff.buffer = ZSTDMT_getBuffer(mtctx->bufPool);
if (mtctx->inBuff.buffer.start == NULL) return ERROR(memory_allocation);
mtctx->inBuff.filled = 0;
}
{ size_t const toLoad = MIN(input->size - input->pos, mtctx->inBuffSize - mtctx->inBuff.filled);
DEBUGLOG(5, "inBuff:%08X; inBuffSize=%u; ToCopy=%u", (U32)(size_t)mtctx->inBuff.buffer.start, (U32)mtctx->inBuffSize, (U32)toLoad);
memcpy((char*)mtctx->inBuff.buffer.start + mtctx->inBuff.filled, (const char*)input->src + input->pos, toLoad);
input->pos += toLoad;
mtctx->inBuff.filled += toLoad;
} }
if ( (mtctx->inBuff.filled >= newJobThreshold) /* filled enough : let's compress */
&& (mtctx->nextJobID <= mtctx->doneJobID + mtctx->jobIDMask) ) { /* avoid overwriting job round buffer */
CHECK_F( ZSTDMT_createCompressionJob(mtctx, mtctx->targetSectionSize, 0 /* endFrame */) );
}
/* check for potential compressed data ready to be flushed */
CHECK_F( ZSTDMT_flushNextJob(mtctx, output, (mtctx->inBuff.filled == mtctx->inBuffSize) /* blockToFlush */) ); /* block if it wasn't possible to create new job due to saturation */
if (input->pos < input->size) /* input not consumed : do not flush yet */
endOp = ZSTD_e_continue;
switch(endOp)
{
case ZSTD_e_flush:
return ZSTDMT_flushStream(mtctx, output);
case ZSTD_e_end:
return ZSTDMT_endStream(mtctx, output);
case ZSTD_e_continue:
return 1;
default:
return ERROR(GENERIC); /* invalid endDirective */
}
}
size_t ZSTDMT_compressStream(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
{
CHECK_F( ZSTDMT_compressStream_generic(zcs, output, input, ZSTD_e_continue) );
/* recommended next input size : fill current input buffer */
return zcs->inBuffSize - zcs->inBuff.filled; /* note : could be zero when input buffer is fully filled and no more availability to create new job */
}
static size_t ZSTDMT_flushStream_internal(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output, unsigned endFrame)
{
size_t const srcSize = zcs->inBuff.filled - zcs->dictSize;
if ( ((srcSize > 0) || (endFrame && !zcs->frameEnded))
&& (zcs->nextJobID <= zcs->doneJobID + zcs->jobIDMask) ) {
CHECK_F( ZSTDMT_createCompressionJob(zcs, srcSize, endFrame) );
}
/* check if there is any data available to flush */
return ZSTDMT_flushNextJob(zcs, output, 1 /* blockToFlush */);
}
size_t ZSTDMT_flushStream(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output)
{
DEBUGLOG(5, "ZSTDMT_flushStream");
if (zcs->nbThreads==1)
return ZSTD_flushStream(zcs->cctxPool->cctx[0], output);
return ZSTDMT_flushStream_internal(zcs, output, 0 /* endFrame */);
}
size_t ZSTDMT_endStream(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output)
{
DEBUGLOG(4, "ZSTDMT_endStream");
if (zcs->nbThreads==1)
return ZSTD_endStream(zcs->cctxPool->cctx[0], output);
return ZSTDMT_flushStream_internal(zcs, output, 1 /* endFrame */);
}