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


/* ======   Compiler specifics   ====== */
#if defined(_MSC_VER)
#  pragma warning(disable : 4204)   /* disable: C4204: non-constant aggregate initializer */
#endif


/* ======   Dependencies   ====== */
#include "../common/allocations.h" /* ZSTD_customMalloc, ZSTD_customCalloc, ZSTD_customFree */
#include "../common/zstd_deps.h"   /* ZSTD_memmove, ZSTD_memset, INT_MAX, UINT_MAX */
#include "../common/mem.h"         /* MEM_STATIC */
#include "../common/pool.h"        /* threadpool */
#include "../common/threading.h"   /* mutex */
#include "zstd_compress_internal.h" /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */
#include "zstd_ldm.h"
#include "zstdmt_compress.h"

/* The Rust MT parameter-update policy receives only this scalar snapshot.
 * Keep the private ZSTDMT_CCtx and ZSTD_CCtx_params layouts in this
 * translation unit. */
typedef struct {
    int compressionLevel;
    int cctxSrcSizeHint;
    U64 srcSizeHint;
    size_t dictSize;
    int mode;
    int enableLdm;
    U32 ldmDefaultWindowLog;
    ZSTD_compressionParameters overrides;
    int useRowMatchFinder;
    U32 exclusionMask;
    U32 savedWindowLog;
} ZSTDMT_RustCParamsUpdateProjection;
typedef char ZSTDMT_rust_cparams_update_projection_layout[
        (offsetof(ZSTDMT_RustCParamsUpdateProjection, compressionLevel) == 0
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, cctxSrcSizeHint)
                == sizeof(int)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, srcSizeHint)
                == 2 * sizeof(int)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, dictSize) == 16
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, mode)
                == (sizeof(void*) == 8 ? 24 : 20)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, enableLdm)
                == (sizeof(void*) == 8 ? 28 : 24)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, ldmDefaultWindowLog)
                == (sizeof(void*) == 8 ? 32 : 28)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, overrides)
                == (sizeof(void*) == 8 ? 36 : 32)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, useRowMatchFinder)
                == (sizeof(void*) == 8 ? 64 : 60)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, exclusionMask)
                == (sizeof(void*) == 8 ? 68 : 64)
         && offsetof(ZSTDMT_RustCParamsUpdateProjection, savedWindowLog)
                == (sizeof(void*) == 8 ? 72 : 68)
         && sizeof(ZSTDMT_RustCParamsUpdateProjection)
                == (sizeof(void*) == 8 ? 80 : 72))
        ? 1 : -1];

typedef struct {
    int compressionLevel;
    ZSTD_compressionParameters cParams;
} ZSTDMT_RustCParamsUpdateResult;
typedef char ZSTDMT_rust_cparams_update_result_layout[
        (offsetof(ZSTDMT_RustCParamsUpdateResult, compressionLevel) == 0
         && offsetof(ZSTDMT_RustCParamsUpdateResult, cParams) == sizeof(int)
         && sizeof(ZSTDMT_RustCParamsUpdateResult)
                == sizeof(int) + sizeof(ZSTD_compressionParameters))
        ? 1 : -1];

ZSTDMT_RustCParamsUpdateResult ZSTDMT_rust_updateCParamsWhileCompressing(
        ZSTDMT_RustCParamsUpdateProjection projection);

/* Defined in zstd_compress.c so all C translation units use the same
 * preprocessor-derived block-compressor exclusion mask. */
U32 ZSTD_getCParamsExclusionMask(void);

/* Guards code to support resizing the SeqPool.
 * We will want to resize the SeqPool to save memory in the future.
 * Until then, comment the code out since it is unused.
 */
#define ZSTD_RESIZE_SEQPOOL 0

/* ======   Debug   ====== */
#if defined(DEBUGLEVEL) && (DEBUGLEVEL>=2) \
    && !defined(_MSC_VER) \
    && !defined(__MINGW32__)

#  include <stdio.h>
#  include <unistd.h>
#  include <sys/times.h>

#  define DEBUG_PRINTHEX(l,p,n)                                       \
    do {                                                              \
        unsigned debug_u;                                             \
        for (debug_u=0; debug_u<(n); debug_u++)                       \
            RAWLOG(l, "%02X ", ((const unsigned char*)(p))[debug_u]); \
        RAWLOG(l, " \n");                                             \
    } while (0)

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 ZSTD_PTHREAD_MUTEX_LOCK(mutex)                                                  \
    do {                                                                                \
        if (DEBUGLEVEL >= MUTEX_WAIT_TIME_DLEVEL) {                                     \
            unsigned long long const beforeTime = GetCurrentClockTimeMicroseconds();    \
            ZSTD_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 {                                                                        \
            ZSTD_pthread_mutex_lock(mutex);                                             \
        }                                                                               \
    } while (0)

#else

#  define ZSTD_PTHREAD_MUTEX_LOCK(m) ZSTD_pthread_mutex_lock(m)
#  define DEBUG_PRINTHEX(l,p,n) do { } while (0)

#endif


/* =====   Buffer Pool   ===== */
/* a single Buffer Pool can be invoked from multiple threads in parallel */

typedef struct buffer_s {
    void* start;
    size_t capacity;
} Buffer;

static const Buffer g_nullBuffer = { NULL, 0 };

/* The Rust module owns the synchronized pool state.  Keep a C wrapper so
 * custom allocation of the containing ZSTDMT context remains unchanged. */
typedef struct ZSTDMT_RustBufferPool_s ZSTDMT_RustBufferPool;
typedef struct {
    void* start;
    size_t capacity;
} ZSTDMT_RustBuffer;

ZSTDMT_RustBufferPool* ZSTDMT_rust_buffer_pool_create(unsigned maxNbBuffers,
                                                       ZSTD_customMem cMem);
void ZSTDMT_rust_buffer_pool_free(ZSTDMT_RustBufferPool* pool);
size_t ZSTDMT_rust_buffer_pool_sizeof(const ZSTDMT_RustBufferPool* pool);
size_t ZSTDMT_rust_sizeofBufferPool(size_t wrapperSize, size_t rustPoolSize);
void ZSTDMT_rust_buffer_pool_set_size(ZSTDMT_RustBufferPool* pool, size_t bSize);
ZSTDMT_RustBufferPool* ZSTDMT_rust_buffer_pool_expand(ZSTDMT_RustBufferPool* pool,
                                                       unsigned maxNbBuffers);
ZSTDMT_RustBuffer ZSTDMT_rust_buffer_pool_get(ZSTDMT_RustBufferPool* pool);
void ZSTDMT_rust_buffer_pool_release(ZSTDMT_RustBufferPool* pool,
                                     ZSTDMT_RustBuffer buffer);
ZSTDMT_RustBuffer ZSTDMT_rust_buffer_pool_resize(ZSTDMT_RustBufferPool* pool,
                                                  ZSTDMT_RustBuffer buffer);

typedef struct {
    size_t error;
    size_t lastBlockSize;
} ZSTDMT_chunkProcessResult;

typedef struct {
    void* dst;
    size_t dstCapacity;
    int* stage;
    int noDictIDFlag;
    int checksumFlag;
    int contentSizeFlag;
    int format;
    U32 windowLog;
    U64 pledgedSrcSizePlusOne;
    U32 dictID;
    U32* repCodes;
} ZSTDMT_RustCompressionJobFrameHeaderState;
typedef char ZSTDMT_compression_job_frame_header_state_layout[
        (offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, dst) == 0
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, dstCapacity)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, stage)
                == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, noDictIDFlag)
                == 3 * sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, checksumFlag)
                == 3 * sizeof(void*) + sizeof(int)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, contentSizeFlag)
                == 3 * sizeof(void*) + 2 * sizeof(int)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, format)
                == 3 * sizeof(void*) + 3 * sizeof(int)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, windowLog)
                == 3 * sizeof(void*) + 4 * sizeof(int)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, pledgedSrcSizePlusOne)
                == (sizeof(void*) == 8 ? 6 * sizeof(void*) : 8 * sizeof(void*))
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, dictID)
                == (sizeof(void*) == 8 ? 6 * sizeof(void*) : 8 * sizeof(void*))
                        + sizeof(U64)
         && offsetof(ZSTDMT_RustCompressionJobFrameHeaderState, repCodes)
                == (sizeof(void*) == 8 ? 8 * sizeof(void*) : 11 * sizeof(void*))
         && sizeof(ZSTDMT_RustCompressionJobFrameHeaderState)
                == (sizeof(void*) == 8 ? 72 : 48))
        ? 1 : -1];

typedef struct ZSTDMT_RustCompressionJobSequenceState_s
        ZSTDMT_RustCompressionJobSequenceState;

typedef struct {
    unsigned firstJob;
    unsigned lastJob;
    const ZSTDMT_RustCompressionJobFrameHeaderState* frameHeaderState;
    const ZSTDMT_RustCompressionJobSequenceState* sequenceState;
} ZSTDMT_RustCompressionJobProjection;
typedef char ZSTDMT_compression_job_projection_layout[
        (offsetof(ZSTDMT_RustCompressionJobProjection, firstJob) == 0
         && offsetof(ZSTDMT_RustCompressionJobProjection, lastJob) == sizeof(unsigned)
         && offsetof(ZSTDMT_RustCompressionJobProjection, frameHeaderState)
                == 2 * sizeof(unsigned)
         && offsetof(ZSTDMT_RustCompressionJobProjection, sequenceState)
                == 2 * sizeof(unsigned) + sizeof(void*)
         && sizeof(ZSTDMT_RustCompressionJobProjection)
                == 2 * sizeof(unsigned) + 2 * sizeof(void*))
        ? 1 : -1];

typedef struct {
    unsigned firstJob;
    unsigned hasCDict;
} ZSTDMT_RustCompressionJobBeginProjection;
typedef char ZSTDMT_compression_job_begin_projection_layout[
        (offsetof(ZSTDMT_RustCompressionJobBeginProjection, firstJob) == 0
         && offsetof(ZSTDMT_RustCompressionJobBeginProjection, hasCDict)
                == sizeof(unsigned)
         && sizeof(ZSTDMT_RustCompressionJobBeginProjection)
                == 2 * sizeof(unsigned))
        ? 1 : -1];

typedef struct {
    int status;
    size_t toFlush;
    size_t outputPos;
    size_t dstFlushed;
} ZSTDMT_flushPublicationResult;

typedef void (*ZSTDMT_chunkProgressFn)(void* opaque, size_t cSize, size_t consumed);
typedef size_t (*ZSTDMT_compressionJobStepFn)(void* opaque);
typedef void (*ZSTDMT_compressionJobVoidFn)(void* opaque);
typedef ZSTDMT_chunkProcessResult (*ZSTDMT_compressionJobCompressFn)(
        void* opaque, unsigned lastJob);
typedef void (*ZSTDMT_compressionJobSizeFn)(void* opaque, size_t size);
typedef size_t (*ZSTDMT_compressionJobSetParameterFn)(void* opaque, int value);
typedef void (*ZSTDMT_compressionJobApplySequencesFn)(
        void* opaque, void* cctx, void* sequences, size_t nbSequences);

typedef struct {
    void* callbackContext;
    size_t* cSize;
    size_t* consumed;
    ZSTDMT_compressionJobVoidFn lock;
    ZSTDMT_compressionJobVoidFn signal;
    ZSTDMT_compressionJobVoidFn unlock;
    ZSTDMT_chunkProgressFn debug;
} ZSTDMT_RustCompressionJobProgressProjection;
typedef char ZSTDMT_compression_job_progress_projection_layout[
        (offsetof(ZSTDMT_RustCompressionJobProgressProjection, callbackContext)
                == 0
         && offsetof(ZSTDMT_RustCompressionJobProgressProjection, cSize)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobProgressProjection, consumed)
                == sizeof(void*) + sizeof(size_t)
         && offsetof(ZSTDMT_RustCompressionJobProgressProjection, lock)
                == sizeof(void*) + 2 * sizeof(size_t)
         && offsetof(ZSTDMT_RustCompressionJobProgressProjection, signal)
                == sizeof(void*) + 2 * sizeof(size_t) + sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobProgressProjection, unlock)
                == sizeof(void*) + 2 * sizeof(size_t) + 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobProgressProjection, debug)
                == sizeof(void*) + 2 * sizeof(size_t) + 3 * sizeof(void*)
         && sizeof(ZSTDMT_RustCompressionJobProgressProjection)
                == sizeof(void*) + 2 * sizeof(size_t) + 4 * sizeof(void*))
        ? 1 : -1];

void ZSTDMT_rust_compressionJobProgress(
        void* opaque, size_t cSize, size_t consumed);

typedef struct {
    void* callbackContext;
    size_t* cSize;
    size_t* consumed;
    size_t srcSize;
    ZSTDMT_compressionJobVoidFn lock;
    ZSTDMT_compressionJobVoidFn signal;
    ZSTDMT_compressionJobVoidFn unlock;
    ZSTDMT_compressionJobSizeFn validateConsumed;
} ZSTDMT_RustCompressionJobFinishPublicationProjection;
typedef char ZSTDMT_compression_job_finish_publication_projection_layout[
        (offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection,
                  callbackContext) == 0
         && offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection, cSize)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection,
                     consumed)
                == sizeof(void*) + sizeof(size_t)
         && offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection,
                     srcSize)
                == sizeof(void*) + 2 * sizeof(size_t)
         && offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection, lock)
                == sizeof(void*) + 3 * sizeof(size_t)
         && offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection, signal)
                == sizeof(void*) + 3 * sizeof(size_t) + sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection,
                     unlock)
                == sizeof(void*) + 3 * sizeof(size_t) + 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFinishPublicationProjection,
                     validateConsumed)
                == sizeof(void*) + 3 * sizeof(size_t) + 3 * sizeof(void*)
         && sizeof(ZSTDMT_RustCompressionJobFinishPublicationProjection)
                == sizeof(void*) + 3 * sizeof(size_t) + 4 * sizeof(void*))
        ? 1 : -1];

typedef struct {
    void* callbackContext;
    size_t srcSize;
    ZSTDMT_compressionJobVoidFn ensureFinished;
    ZSTDMT_RustCompressionJobFinishPublicationProjection publication;
    ZSTDMT_compressionJobVoidFn releaseSeq;
    ZSTDMT_compressionJobVoidFn releaseCCtx;
} ZSTDMT_RustCompressionJobFinishProjection;
typedef char ZSTDMT_compression_job_finish_projection_layout[
        (offsetof(ZSTDMT_RustCompressionJobFinishProjection, callbackContext) == 0
         && offsetof(ZSTDMT_RustCompressionJobFinishProjection, srcSize)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFinishProjection, ensureFinished)
                == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFinishProjection, publication)
                == 3 * sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobFinishProjection, releaseSeq)
                == 3 * sizeof(void*)
                   + sizeof(ZSTDMT_RustCompressionJobFinishPublicationProjection)
         && offsetof(ZSTDMT_RustCompressionJobFinishProjection, releaseCCtx)
                == 4 * sizeof(void*)
                   + sizeof(ZSTDMT_RustCompressionJobFinishPublicationProjection)
         && sizeof(ZSTDMT_RustCompressionJobFinishProjection)
                == 5 * sizeof(void*)
                   + sizeof(ZSTDMT_RustCompressionJobFinishPublicationProjection))
        ? 1 : -1];

typedef struct {
    void* callbackContext;
    unsigned firstJob;
    ZSTDMT_compressionJobVoidFn assertNoExtDict;
    ZSTDMT_compressionJobVoidFn trace;
} ZSTDMT_RustCompressionJobTraceProjection;
typedef char ZSTDMT_compression_job_trace_projection_layout[
        (offsetof(ZSTDMT_RustCompressionJobTraceProjection, callbackContext) == 0
         && offsetof(ZSTDMT_RustCompressionJobTraceProjection, firstJob)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobTraceProjection, assertNoExtDict)
                == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobTraceProjection, trace)
                == 3 * sizeof(void*)
         && sizeof(ZSTDMT_RustCompressionJobTraceProjection)
                == 4 * sizeof(void*))
        ? 1 : -1];

typedef struct {
    int checksumFlag;
    int ldmEnable;
    unsigned nbWorkers;
} ZSTDMT_RustCompressionJobParameters;
typedef char ZSTDMT_compression_job_parameters_layout[
        (offsetof(ZSTDMT_RustCompressionJobParameters, checksumFlag) == 0
         && offsetof(ZSTDMT_RustCompressionJobParameters, ldmEnable) == sizeof(int)
         && offsetof(ZSTDMT_RustCompressionJobParameters, nbWorkers) == 2 * sizeof(int)
         && sizeof(ZSTDMT_RustCompressionJobParameters)
                == 2 * sizeof(int) + sizeof(unsigned))
        ? 1 : -1];

typedef struct {
    int ldmEnabled;
    int hasDestination;
} ZSTDMT_RustCompressionJobResourceProjection;
typedef char ZSTDMT_compression_job_resource_projection_layout[
        (offsetof(ZSTDMT_RustCompressionJobResourceProjection, ldmEnabled) == 0
         && offsetof(ZSTDMT_RustCompressionJobResourceProjection, hasDestination)
                == sizeof(int)
         && sizeof(ZSTDMT_RustCompressionJobResourceProjection)
                == 2 * sizeof(int))
        ? 1 : -1];

typedef int (*ZSTDMT_compressionJobResourceReadyFn)(void* opaque);

ZSTDMT_RustCompressionJobParameters ZSTDMT_rust_prepareCompressionJobParameters(
        unsigned jobID, int checksumFlag, int ldmEnable, unsigned nbWorkers);

size_t ZSTDMT_rust_compressionJobAcquireResources(
        const ZSTDMT_RustCompressionJobResourceProjection* projection,
        void* opaque,
        ZSTDMT_compressionJobVoidFn acquireCCtx,
        ZSTDMT_compressionJobVoidFn acquireRawSeqStore,
        ZSTDMT_compressionJobResourceReadyFn hasCCtx,
        ZSTDMT_compressionJobStepFn acquireDestinationBuffer,
        ZSTDMT_compressionJobResourceReadyFn hasRawSeqStore,
        ZSTDMT_compressionJobVoidFn publishDestination);

size_t ZSTDMT_rust_compressionJobBegin(
        const ZSTDMT_RustCompressionJobBeginProjection* projection,
        void* opaque,
        ZSTDMT_compressionJobStepFn beginWithCDict,
        ZSTDMT_compressionJobSetParameterFn setForceMaxWindow,
        ZSTDMT_compressionJobStepFn setDeterministicRefPrefix,
        ZSTDMT_compressionJobStepFn beginWithPrefix,
        ZSTDMT_compressionJobVoidFn publishFrameHeader);

void ZSTDMT_rust_compressionJob(
        const ZSTDMT_RustCompressionJobProjection* projection,
        const ZSTDMT_RustCompressionJobFinishProjection* finishProjection,
        void* opaque,
        ZSTDMT_compressionJobStepFn acquireResources,
        ZSTDMT_compressionJobVoidFn prepareParameters,
        ZSTDMT_compressionJobVoidFn generateSequences,
        ZSTDMT_compressionJobStepFn beginJob,
        ZSTDMT_compressionJobApplySequencesFn applySequences,
        ZSTDMT_compressionJobCompressFn compressJob,
        ZSTDMT_compressionJobVoidFn traceJob);
void ZSTDMT_rust_compressionJobTrace(
        const ZSTDMT_RustCompressionJobTraceProjection* projection);

ZSTDMT_chunkProcessResult ZSTDMT_rust_compressJobChunks(
        ZSTD_CCtx* cctx, const void* src, size_t srcSize,
        void* dst, size_t dstCapacity, size_t chunkSize, unsigned lastJob,
        void* progressContext, ZSTDMT_chunkProgressFn progressCallback);

ZSTDMT_flushPublicationResult ZSTDMT_rust_publishJobOutput(
        void* outputDst, size_t outputSize, size_t outputPos,
        const void* jobDst, size_t jobCapacity,
        size_t cSize, size_t dstFlushed);

typedef struct {
    size_t consumed;
    size_t cSize;
    size_t srcSize;
    const void* dstStart;
    size_t dstCapacity;
    size_t dstFlushed;
    unsigned frameChecksumNeeded;
} ZSTDMT_RustFlushJobProjection;
typedef struct {
    void* dst;
    size_t dstCapacity;
    size_t cSize;
    const XXH64_state_t* checksumState;
} ZSTDMT_RustFrameChecksumProjection;
typedef char ZSTDMT_frame_checksum_projection_layout[
        (offsetof(ZSTDMT_RustFrameChecksumProjection, dst) == 0
         && offsetof(ZSTDMT_RustFrameChecksumProjection, dstCapacity)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustFrameChecksumProjection, cSize)
                == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustFrameChecksumProjection, checksumState)
                == 3 * sizeof(void*)
         && sizeof(ZSTDMT_RustFrameChecksumProjection)
                == 4 * sizeof(void*))
        ? 1 : -1];
typedef struct {
    unsigned doneJobID;
    unsigned nextJobID;
    unsigned jobIDMask;
    unsigned jobReady;
    unsigned frameEnded;
    size_t inBuffFilled;
} ZSTDMT_RustFlushContextProjection;
typedef struct {
    size_t result;
    size_t outputPos;
    unsigned updateAllJobsCompleted;
    unsigned allJobsCompleted;
} ZSTDMT_RustFlushProducedResult;
typedef void (*ZSTDMT_flushProjectJobFn)(
        void* opaque, unsigned jobID, unsigned blockToFlush,
        ZSTDMT_RustFlushJobProjection* projection);
typedef void (*ZSTDMT_flushChecksumFn)(
        void* opaque, unsigned jobID,
        ZSTDMT_RustFlushJobProjection* projection);
typedef void (*ZSTDMT_flushUpdateJobFn)(
        void* opaque, unsigned jobID, size_t dstFlushed);
typedef void (*ZSTDMT_flushCompleteJobFn)(
        void* opaque, unsigned jobID, size_t srcSize, size_t cSize);
typedef void (*ZSTDMT_flushWaitForAllJobsFn)(void* opaque);
typedef void (*ZSTDMT_flushReleaseAllJobResourcesFn)(void* opaque);
ZSTDMT_RustFlushProducedResult ZSTDMT_rust_flushProduced(
        const ZSTDMT_RustFlushContextProjection* context,
        void* outputDst, size_t outputSize, size_t outputPos,
        unsigned blockToFlush, unsigned end, void* opaque,
        ZSTDMT_flushProjectJobFn projectJob,
        ZSTDMT_flushChecksumFn addFrameChecksum,
        ZSTDMT_flushUpdateJobFn updateJob,
        ZSTDMT_flushCompleteJobFn completeJob,
        ZSTDMT_flushWaitForAllJobsFn waitForAllJobs,
        ZSTDMT_flushReleaseAllJobResourcesFn releaseAllJobResources);
size_t ZSTDMT_rust_writeFrameChecksum(
        const ZSTDMT_RustFrameChecksumProjection* projection);

/* The Rust outer scheduler sees only this scalar snapshot.  The MT context,
 * reusable input buffer, worker pool, and all synchronization remain private
 * to this translation unit. */
typedef struct {
    unsigned frameEnded;
    unsigned jobReady;
    void* inBuffStart;
    size_t inBuffCapacity;
    size_t inBuffFilled;
    size_t targetSectionSize;
    int rsyncable;
    U64 rsyncPrimePower;
    U64 rsyncHitMask;
} ZSTDMT_RustCompressStreamContextProjection;
typedef struct {
    void* bufferStart;
    size_t bufferCapacity;
    size_t bufferFilled;
} ZSTDMT_RustStreamInputRangeProjection;
typedef struct {
    const void* src;
    size_t size;
    size_t pos;
} ZSTDMT_RustStreamInputProjection;
typedef struct {
    void* dst;
    size_t size;
    size_t pos;
} ZSTDMT_RustStreamOutputProjection;
typedef struct {
    size_t toLoad;
    int flush;
} ZSTDMT_RustSyncPointProjection;
typedef struct {
    size_t result;
    size_t outputPos;
} ZSTDMT_RustStreamFlushResult;
typedef struct {
    size_t result;
    unsigned inBuffActive;
} ZSTDMT_RustStreamCreateJobResult;
typedef char ZSTDMT_stream_create_job_result_layout[
        (offsetof(ZSTDMT_RustStreamCreateJobResult, result) == 0
         && offsetof(ZSTDMT_RustStreamCreateJobResult, inBuffActive)
                == sizeof(size_t)
         && sizeof(ZSTDMT_RustStreamCreateJobResult) == 2 * sizeof(size_t))
        ? 1 : -1];
typedef struct {
    size_t result;
    size_t inputPos;
    size_t outputPos;
    size_t inBuffFilled;
} ZSTDMT_RustCompressStreamResult;
typedef char ZSTDMT_compress_stream_result_layout[
        (offsetof(ZSTDMT_RustCompressStreamResult, result) == 0
         && offsetof(ZSTDMT_RustCompressStreamResult, inputPos) == sizeof(size_t)
         && offsetof(ZSTDMT_RustCompressStreamResult, outputPos) == 2 * sizeof(size_t)
         && offsetof(ZSTDMT_RustCompressStreamResult, inBuffFilled)
                == 3 * sizeof(size_t)
         && sizeof(ZSTDMT_RustCompressStreamResult) == 4 * sizeof(size_t))
        ? 1 : -1];
typedef int (*ZSTDMT_streamTryGetInputRangeFn)(
        void* opaque, ZSTDMT_RustStreamInputRangeProjection* projection);
typedef ZSTDMT_RustStreamCreateJobResult (*ZSTDMT_streamCreateJobFn)(
        void* opaque, size_t srcSize, unsigned end);
typedef ZSTDMT_RustStreamFlushResult (*ZSTDMT_streamFlushProducedFn)(
        void* opaque, void* outputDst, size_t outputSize, size_t outputPos,
        unsigned blockToFlush, unsigned end);
ZSTDMT_RustCompressStreamResult ZSTDMT_rust_compressStreamGeneric(
        const ZSTDMT_RustCompressStreamContextProjection* context,
        const ZSTDMT_RustStreamInputProjection* input,
        const ZSTDMT_RustStreamOutputProjection* output,
        unsigned end, void* opaque,
        ZSTDMT_streamTryGetInputRangeFn tryGetInputRange,
        ZSTDMT_streamCreateJobFn createJob,
        ZSTDMT_streamFlushProducedFn flushProduced);

typedef struct {
    unsigned lastJob;
    size_t srcSize;
    unsigned firstJob;
    void* dstStart;
    size_t dstCapacity;
    size_t consumed;
} ZSTDMT_RustEmptyBlockJobProjection;
typedef struct {
    ZSTDMT_RustBuffer buffer;
    size_t cSize;
    unsigned clearSource;
} ZSTDMT_RustEmptyBlockResult;
typedef ZSTDMT_RustBuffer (*ZSTDMT_bufferGetFn)(void* opaque);
ZSTDMT_RustEmptyBlockResult ZSTDMT_rust_writeLastEmptyBlock(
        const ZSTDMT_RustEmptyBlockJobProjection* projection,
        void* opaque, ZSTDMT_bufferGetFn getBuffer);

typedef struct {
    unsigned doneJobID;
    unsigned nextJobID;
    unsigned jobIDMask;
    unsigned jobReady;
    const void* srcStart;
    size_t srcSize;
    size_t inBuffFilled;
    const void* prefixStart;
    size_t prefixSize;
    size_t targetPrefixSize;
    unsigned endFrame;
    unsigned checksumFlag;
} ZSTDMT_RustCreateJobProjection;
typedef struct {
    const void* srcStart;
    size_t srcSize;
    const void* prefixStart;
    size_t prefixSize;
    const void* nextPrefixStart;
    size_t nextPrefixSize;
    size_t roundBuffPosDelta;
    unsigned jobNumber;
    unsigned firstJob;
    unsigned lastJob;
    unsigned frameChecksumNeeded;
    unsigned clearChecksumFlag;
} ZSTDMT_RustJobInitialization;
typedef struct {
    size_t returnCode;
    unsigned action;
    unsigned jobID;
    unsigned jobNumber;
    unsigned nextJobID;
    unsigned jobReady;
} ZSTDMT_RustCreateJobResult;
enum {
    ZSTDMT_CREATE_JOB_TABLE_FULL = 0,
    ZSTDMT_CREATE_JOB_POST = 1,
    ZSTDMT_CREATE_JOB_EMPTY = 2
};
typedef void (*ZSTDMT_prepareJobFn)(void* opaque, unsigned jobID,
                                   const ZSTDMT_RustJobInitialization* init);
typedef void (*ZSTDMT_prepareFrameStateFn)(void* opaque);
typedef void (*ZSTDMT_writeEmptyJobFn)(void* opaque, unsigned jobID);
typedef int (*ZSTDMT_tryAddJobFn)(void* opaque, unsigned jobID);
void ZSTDMT_rust_prepareCompressionJob(
        void* opaque, unsigned jobID,
        const ZSTDMT_RustJobInitialization* initialization,
        ZSTDMT_prepareJobFn initializeJob,
        ZSTDMT_prepareJobFn resetInputState,
        ZSTDMT_prepareFrameStateFn setFrameEnded,
        ZSTDMT_prepareFrameStateFn clearChecksumFlag);
ZSTDMT_RustCreateJobResult ZSTDMT_rust_createCompressionJob(
        const ZSTDMT_RustCreateJobProjection* projection,
        void* opaque, ZSTDMT_prepareJobFn prepareJob,
        ZSTDMT_writeEmptyJobFn writeEmptyJob, ZSTDMT_tryAddJobFn tryAddJob);

typedef struct {
    rawSeq* seq;
    size_t pos;
    size_t posInSequence;
    size_t size;
    size_t capacity;
} ZSTDMT_RustRawSeqStore;

typedef char ZSTDMT_rust_raw_seq_layout[
        (sizeof(rawSeq) == 3 * sizeof(U32)) ? 1 : -1];
typedef char ZSTDMT_rust_raw_seq_store_layout[
        (sizeof(ZSTDMT_RustRawSeqStore) == sizeof(RawSeqStore_t)
         && offsetof(ZSTDMT_RustRawSeqStore, pos) == offsetof(RawSeqStore_t, pos)
         && offsetof(ZSTDMT_RustRawSeqStore, capacity) == offsetof(RawSeqStore_t, capacity))
                ? 1 : -1];

struct ZSTDMT_RustCompressionJobSequenceState_s {
    ZSTD_CCtx** cctx;
    ZSTDMT_RustRawSeqStore* rawSeqStore;
    int ldmEnabled;
};
typedef char ZSTDMT_compression_job_sequence_state_layout[
        (offsetof(ZSTDMT_RustCompressionJobSequenceState, cctx) == 0
         && offsetof(ZSTDMT_RustCompressionJobSequenceState, rawSeqStore)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustCompressionJobSequenceState, ldmEnabled)
                == 2 * sizeof(void*)
         && sizeof(ZSTDMT_RustCompressionJobSequenceState)
                == (sizeof(void*) == 8 ? 24 : 12))
        ? 1 : -1];

ZSTDMT_RustRawSeqStore ZSTDMT_rust_bufferToSeq(ZSTDMT_RustBuffer buffer);
ZSTDMT_RustBuffer ZSTDMT_rust_seqToBuffer(ZSTDMT_RustRawSeqStore seq);
typedef int (*ZSTDMT_serialWaitForTurnFn)(void* opaque, unsigned jobID);
typedef void (*ZSTDMT_serialLdmWindowUpdateFn)(
        void* opaque, ZSTDMT_RustRawSeqStore* seqStore,
        const void* src, size_t srcSize);
typedef void (*ZSTDMT_serialLdmGenerateSequencesFn)(
        void* opaque, ZSTDMT_RustRawSeqStore* seqStore,
        const void* src, size_t srcSize);
typedef void (*ZSTDMT_serialLdmPublishWindowFn)(void* opaque);
typedef void (*ZSTDMT_serialAdvanceFn)(void* opaque);
typedef void (*ZSTDMT_serialStateLockFn)(void* opaque);
typedef void (*ZSTDMT_serialStateWaitFn)(void* opaque);
typedef struct {
    void* callbackContext;
    unsigned* nextJobID;
    ZSTDMT_serialStateLockFn lock;
    ZSTDMT_serialStateWaitFn wait;
    unsigned jobID;
} ZSTDMT_RustSerialWaitForTurnState;
typedef char ZSTDMT_rust_serial_wait_for_turn_state_layout[
        (offsetof(ZSTDMT_RustSerialWaitForTurnState, callbackContext) == 0
         && offsetof(ZSTDMT_RustSerialWaitForTurnState, nextJobID) == sizeof(void*)
         && offsetof(ZSTDMT_RustSerialWaitForTurnState, lock) == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialWaitForTurnState, wait) == 3 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialWaitForTurnState, jobID) == 4 * sizeof(void*)
         && sizeof(ZSTDMT_RustSerialWaitForTurnState) == 5 * sizeof(void*)) ? 1 : -1];
int ZSTDMT_rust_serialStateWaitForTurn(
        const ZSTDMT_RustSerialWaitForTurnState* state);
typedef void (*ZSTDMT_serialStateBroadcastFn)(void* opaque);
typedef void (*ZSTDMT_serialStateUnlockFn)(void* opaque);
typedef struct {
    void* callbackContext;
    unsigned* nextJobID;
    ZSTDMT_serialStateBroadcastFn broadcast;
    ZSTDMT_serialStateUnlockFn unlock;
} ZSTDMT_RustSerialAdvanceState;
typedef char ZSTDMT_rust_serial_advance_state_layout[
        (offsetof(ZSTDMT_RustSerialAdvanceState, callbackContext) == 0
         && offsetof(ZSTDMT_RustSerialAdvanceState, nextJobID) == sizeof(void*)
         && offsetof(ZSTDMT_RustSerialAdvanceState, broadcast) == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialAdvanceState, unlock) == 3 * sizeof(void*)
         && sizeof(ZSTDMT_RustSerialAdvanceState) == 4 * sizeof(void*)) ? 1 : -1];
void ZSTDMT_rust_serialStateAdvance(const ZSTDMT_RustSerialAdvanceState* state);
void ZSTDMT_rust_serialStateGenSequences(
        ZSTDMT_RustRawSeqStore* seqStore, const void* src, size_t srcSize,
        unsigned jobID, int ldmEnabled, int checksumEnabled, void* opaque,
        XXH64_state_t* checksumState,
        ZSTDMT_serialWaitForTurnFn waitForTurn,
        ZSTDMT_serialLdmWindowUpdateFn updateLdmWindow,
        ZSTDMT_serialLdmGenerateSequencesFn generateLdmSequences,
        ZSTDMT_serialLdmPublishWindowFn publishLdmWindow,
        ZSTDMT_serialAdvanceFn advance);
typedef struct {
    unsigned skip;
    unsigned nextJobID;
} ZSTDMT_RustSerialEnsureFinishedResult;
ZSTDMT_RustSerialEnsureFinishedResult ZSTDMT_rust_serialStateEnsureFinished(
        unsigned nextJobID, unsigned jobID);
typedef void (*ZSTDMT_serialStateCallbackFn)(void* opaque);
typedef void (*ZSTDMT_serialStateSkipFn)(
        void* opaque, unsigned jobID, size_t cSize);
typedef struct {
    void* callbackContext;
    unsigned* nextJobID;
    ZSTDMT_serialStateCallbackFn lock;
    ZSTDMT_serialStateCallbackFn broadcast;
    ZSTDMT_serialStateCallbackFn ldmLock;
    ZSTDMT_serialStateCallbackFn clearLdmWindow;
    ZSTDMT_serialStateCallbackFn ldmSignal;
    ZSTDMT_serialStateCallbackFn ldmUnlock;
    ZSTDMT_serialStateCallbackFn unlock;
    ZSTDMT_serialStateSkipFn onSkip;
    size_t cSize;
    unsigned jobID;
} ZSTDMT_RustSerialEnsureFinishedState;
typedef char ZSTDMT_rust_serial_ensure_finished_state_layout[
        (offsetof(ZSTDMT_RustSerialEnsureFinishedState, callbackContext) == 0
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, nextJobID) == sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, lock) == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, broadcast) == 3 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, ldmLock) == 4 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, clearLdmWindow) == 5 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, ldmSignal) == 6 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, ldmUnlock) == 7 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, unlock) == 8 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, onSkip) == 9 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, cSize) == 10 * sizeof(void*)
         && offsetof(ZSTDMT_RustSerialEnsureFinishedState, jobID)
                == 10 * sizeof(void*) + sizeof(size_t)
         && sizeof(ZSTDMT_RustSerialEnsureFinishedState) == 12 * sizeof(void*)) ? 1 : -1];
void ZSTDMT_rust_serialStateEnsureFinishedOrchestrated(
        const ZSTDMT_RustSerialEnsureFinishedState* state);
typedef void (*ZSTDMT_waitForJobCompleteFn)(
        void* opaque, unsigned jobID, unsigned doneJobID);
unsigned ZSTDMT_rust_waitForAllJobsCompleted(
        unsigned doneJobID, unsigned nextJobID, unsigned jobIDMask,
        void* opaque, ZSTDMT_waitForJobCompleteFn waitForJob);
typedef void (*ZSTDMT_releaseJobResourceFn)(void* opaque, unsigned jobID);
void ZSTDMT_rust_releaseAllJobResources(
        unsigned jobIDMask, void* opaque, ZSTDMT_releaseJobResourceFn releaseJob);
typedef void (*ZSTDMT_waitForLdmLockFn)(void* opaque);
typedef int (*ZSTDMT_waitForLdmOverlapFn)(
        void* opaque, void* bufferStart, size_t bufferCapacity);
typedef void (*ZSTDMT_waitForLdmWaitFn)(void* opaque);
typedef void (*ZSTDMT_waitForLdmUnlockFn)(void* opaque);
typedef struct {
    void* callbackContext;
    void* bufferStart;
    size_t bufferCapacity;
    int ldmEnabled;
    ZSTDMT_waitForLdmLockFn lock;
    ZSTDMT_waitForLdmOverlapFn overlaps;
    ZSTDMT_waitForLdmWaitFn wait;
    ZSTDMT_waitForLdmUnlockFn unlock;
} ZSTDMT_RustWaitForLdmState;
typedef char ZSTDMT_rust_wait_for_ldm_state_layout[
        (offsetof(ZSTDMT_RustWaitForLdmState, callbackContext) == 0
         && offsetof(ZSTDMT_RustWaitForLdmState, bufferStart) == sizeof(void*)
         && offsetof(ZSTDMT_RustWaitForLdmState, bufferCapacity) == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustWaitForLdmState, ldmEnabled) == 3 * sizeof(void*)
         && offsetof(ZSTDMT_RustWaitForLdmState, lock) == 4 * sizeof(void*)
         && offsetof(ZSTDMT_RustWaitForLdmState, overlaps) == 5 * sizeof(void*)
         && offsetof(ZSTDMT_RustWaitForLdmState, wait) == 6 * sizeof(void*)
         && offsetof(ZSTDMT_RustWaitForLdmState, unlock) == 7 * sizeof(void*)
         && sizeof(ZSTDMT_RustWaitForLdmState) == 8 * sizeof(void*)) ? 1 : -1];
void ZSTDMT_rust_waitForLdmComplete(
        const ZSTDMT_RustWaitForLdmState* state);

unsigned ZSTDMT_rust_computeTargetJobLog(unsigned windowLog, unsigned chainLog,
                                         int strategy, int enableLdm);
int ZSTDMT_rust_overlapLog(int overlapLog, int strategy);
size_t ZSTDMT_rust_computeOverlapSize(unsigned windowLog, unsigned chainLog,
                                      int strategy, int overlapLog, int enableLdm);
int ZSTDMT_rust_doesOverlapWindow(const void* bufferStart, size_t bufferCapacity,
                                  const void* nextSrc, const void* base,
                                  const void* dictBase, U32 dictLimit, U32 lowLimit);
void ZSTDMT_rust_findSynchronizationPoint(const void* inputSrc, size_t inputSize,
                                           size_t inputPos, size_t targetSectionSize,
                                           const void* inBuffStart, size_t inBuffFilled,
                                           int rsyncable, U64 primePower, U64 hitMask,
                                           size_t* toLoad, int* flush);
U64 ZSTDMT_rust_rollingHashPrimePower(U32 length);
size_t ZSTDMT_rust_nextInputSizeHint(size_t targetSectionSize,
                                     size_t inBuffFilled);
typedef struct {
    unsigned requestedNbWorkers;
    unsigned currentNbWorkers;
    size_t jobSize;
    size_t jobSizeMin;
    size_t jobSizeMax;
    int enableLdm;
    unsigned windowLog;
    unsigned chainLog;
    int strategy;
    int overlapLog;
    int rsyncable;
    size_t roundBuffCapacity;
    unsigned allJobsCompleted;
} ZSTDMT_RustInitCStreamProjection;
typedef size_t (*ZSTDMT_initResizeFn)(void* opaque, unsigned nbWorkers);
typedef void (*ZSTDMT_initWaitForAllJobsFn)(void* opaque);
typedef void (*ZSTDMT_initReleaseAllJobResourcesFn)(void* opaque);
typedef void (*ZSTDMT_initApplyParametersFn)(void* opaque, size_t jobSize);
typedef size_t (*ZSTDMT_initDictionaryFn)(void* opaque);
typedef void (*ZSTDMT_initSetSizeFn)(void* opaque, size_t size);
typedef void (*ZSTDMT_initSetRsyncFn)(void* opaque, U64 hitMask, U64 primePower);
typedef void (*ZSTDMT_initSetBufferSizeFn)(void* opaque, size_t size);
typedef size_t (*ZSTDMT_initResizeRoundBufferFn)(void* opaque, size_t capacity);
typedef void (*ZSTDMT_initResetStreamFn)(void* opaque);
typedef size_t (*ZSTDMT_initSerialResetFn)(void* opaque, size_t targetSectionSize);
typedef struct {
    unsigned hasDictionary;
    unsigned rawContent;
} ZSTDMT_RustDictionaryProjection;
typedef char ZSTDMT_rust_dictionary_projection_layout[
        (offsetof(ZSTDMT_RustDictionaryProjection, hasDictionary) == 0
         && offsetof(ZSTDMT_RustDictionaryProjection, rawContent)
                == sizeof(unsigned)
         && sizeof(ZSTDMT_RustDictionaryProjection) == 2 * sizeof(unsigned))
        ? 1 : -1];
size_t ZSTDMT_rust_prepareCStreamDictionary(
        const ZSTDMT_RustDictionaryProjection* projection, void* opaque,
        ZSTDMT_initResetStreamFn releaseLocal,
        ZSTDMT_initDictionaryFn createCopied,
        ZSTDMT_initResetStreamFn attachBorrowed);
size_t ZSTDMT_rust_updateCStreamDictionary(
        const ZSTDMT_RustDictionaryProjection* projection, void* opaque,
        ZSTDMT_initResetStreamFn clearLocal,
        ZSTDMT_initResetStreamFn attachBorrowed,
        ZSTDMT_initResetStreamFn setRawPrefix,
        ZSTDMT_initDictionaryFn createReferenced);
typedef struct {
    int enableLdm;
    int checksumEnabled;
    size_t jobSize;
    unsigned windowLog;
    int strategy;
    unsigned hashLog;
    unsigned bucketSizeLog;
    unsigned minMatchLength;
    unsigned hashRateLog;
    unsigned previousHashLog;
    unsigned previousBucketSizeLog;
    size_t ldmEntrySize;
} ZSTDMT_RustSerialResetProjection;
typedef char ZSTDMT_rust_serial_reset_projection_layout[
        (offsetof(ZSTDMT_RustSerialResetProjection, enableLdm) == 0
         && offsetof(ZSTDMT_RustSerialResetProjection, checksumEnabled)
                == sizeof(int)
         && offsetof(ZSTDMT_RustSerialResetProjection, jobSize) == 8
         && offsetof(ZSTDMT_RustSerialResetProjection, windowLog)
                == (sizeof(void*) == 8 ? 16 : 12)
         && offsetof(ZSTDMT_RustSerialResetProjection, strategy)
                == (sizeof(void*) == 8 ? 20 : 16)
         && offsetof(ZSTDMT_RustSerialResetProjection, hashLog)
                == (sizeof(void*) == 8 ? 24 : 20)
         && offsetof(ZSTDMT_RustSerialResetProjection, bucketSizeLog)
                == (sizeof(void*) == 8 ? 28 : 24)
         && offsetof(ZSTDMT_RustSerialResetProjection, minMatchLength)
                == (sizeof(void*) == 8 ? 32 : 28)
         && offsetof(ZSTDMT_RustSerialResetProjection, hashRateLog)
                == (sizeof(void*) == 8 ? 36 : 32)
         && offsetof(ZSTDMT_RustSerialResetProjection, previousHashLog)
                == (sizeof(void*) == 8 ? 40 : 36)
         && offsetof(ZSTDMT_RustSerialResetProjection, previousBucketSizeLog)
                == (sizeof(void*) == 8 ? 44 : 40)
         && offsetof(ZSTDMT_RustSerialResetProjection, ldmEntrySize)
                == (sizeof(void*) == 8 ? 48 : 44)
         && sizeof(ZSTDMT_RustSerialResetProjection)
                == (sizeof(void*) == 8 ? 56 : 48)) ? 1 : -1];
typedef void (*ZSTDMT_serialResetSetLdmParamsFn)(
        void* opaque, int enableLdm, unsigned hashLog,
        unsigned bucketSizeLog, unsigned minMatchLength,
        unsigned hashRateLog, unsigned windowLog);
typedef void (*ZSTDMT_serialResetVoidFn)(void* opaque);
typedef void (*ZSTDMT_serialResetSetNbSeqFn)(void* opaque, size_t nbSeq);
typedef int (*ZSTDMT_serialResetResizeFn)(
        void* opaque, size_t hashSize, size_t numBuckets,
        unsigned bucketLog, unsigned previousBucketLog);
typedef void (*ZSTDMT_serialResetZeroTablesFn)(
        void* opaque, size_t hashSize, size_t numBuckets);
typedef size_t (*ZSTDMT_serialResetLoadRawDictionaryFn)(
        void* opaque, const void* dict, size_t dictSize);
typedef void (*ZSTDMT_serialResetSetLoadedDictEndFn)(
        void* opaque, U32 loadedDictEnd);
typedef void (*ZSTDMT_serialResetPublishFn)(void* opaque, size_t jobSize);
typedef struct {
    const void* dict;
    size_t dictSize;
    int dictContentType;
    int forceWindow;
} ZSTDMT_RustSerialDictionaryProjection;
typedef char ZSTDMT_rust_serial_dictionary_projection_layout[
        (offsetof(ZSTDMT_RustSerialDictionaryProjection, dict) == 0
         && offsetof(ZSTDMT_RustSerialDictionaryProjection, dictSize)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustSerialDictionaryProjection, dictContentType)
                == sizeof(void*) + sizeof(size_t)
         && offsetof(ZSTDMT_RustSerialDictionaryProjection, forceWindow)
                == sizeof(void*) + sizeof(size_t) + sizeof(int)
         && sizeof(ZSTDMT_RustSerialDictionaryProjection)
                == sizeof(void*) + sizeof(size_t) + 2 * sizeof(int))
        ? 1 : -1];
void ZSTDMT_rust_serialStateLoadDictionary(
        const ZSTDMT_RustSerialDictionaryProjection* projection,
        void* opaque, ZSTDMT_serialResetLoadRawDictionaryFn loadRawDictionary,
        ZSTDMT_serialResetSetLoadedDictEndFn setLoadedDictEnd);
int ZSTDMT_rust_serialStateReset(
        const ZSTDMT_RustSerialResetProjection* projection, void* opaque,
        ZSTDMT_serialResetSetLdmParamsFn setLdmParams,
        ZSTDMT_serialResetVoidFn resetNextJob,
        ZSTDMT_serialResetVoidFn resetChecksum,
        ZSTDMT_serialResetSetNbSeqFn setNbSeq,
        ZSTDMT_serialResetVoidFn resetWindow,
        ZSTDMT_serialResetResizeFn resizeTables,
        ZSTDMT_serialResetZeroTablesFn zeroTables,
        ZSTDMT_serialResetVoidFn loadDictionary,
        ZSTDMT_serialResetVoidFn copyWindow,
        ZSTDMT_serialResetPublishFn publishParams);
typedef void (*ZSTDMT_serialStateVoidFn)(void* opaque);
typedef int (*ZSTDMT_serialStateInitFn)(void* opaque);
int ZSTDMT_rust_serialStateInit(
        void* opaque, ZSTDMT_serialStateVoidFn zeroState,
        ZSTDMT_serialStateInitFn initMutex,
        ZSTDMT_serialStateInitFn initCond,
        ZSTDMT_serialStateInitFn initLdmMutex,
        ZSTDMT_serialStateInitFn initLdmCond);
void ZSTDMT_rust_serialStateFree(
        void* opaque, ZSTDMT_serialStateVoidFn destroyMutex,
        ZSTDMT_serialStateVoidFn destroyCond,
        ZSTDMT_serialStateVoidFn destroyLdmMutex,
        ZSTDMT_serialStateVoidFn destroyLdmCond,
        ZSTDMT_serialStateVoidFn freeTables);
typedef void (*ZSTDMT_freeCCtxCallbackFn)(void* opaque);
typedef struct {
    void* callbackContext;
    size_t providedFactory;
    size_t roundBuffPresent;
    ZSTDMT_freeCCtxCallbackFn freeFactory;
    ZSTDMT_freeCCtxCallbackFn releaseAllJobResources;
    ZSTDMT_freeCCtxCallbackFn freeJobs;
    ZSTDMT_freeCCtxCallbackFn freeBufferPool;
    ZSTDMT_freeCCtxCallbackFn freeCCtxPool;
    ZSTDMT_freeCCtxCallbackFn freeSeqPool;
    ZSTDMT_freeCCtxCallbackFn freeSerialState;
    ZSTDMT_freeCCtxCallbackFn freeCDict;
    ZSTDMT_freeCCtxCallbackFn freeRoundBuffer;
    ZSTDMT_freeCCtxCallbackFn freeMTctx;
} ZSTDMT_RustFreeCCtxState;
typedef char ZSTDMT_rust_free_cctx_state_layout[
        (sizeof(ZSTDMT_freeCCtxCallbackFn) == sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, callbackContext) == 0
         && offsetof(ZSTDMT_RustFreeCCtxState, providedFactory) == sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, roundBuffPresent) == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeFactory) == 3 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, releaseAllJobResources) == 4 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeJobs) == 5 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeBufferPool) == 6 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeCCtxPool) == 7 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeSeqPool) == 8 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeSerialState) == 9 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeCDict) == 10 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeRoundBuffer) == 11 * sizeof(void*)
         && offsetof(ZSTDMT_RustFreeCCtxState, freeMTctx) == 12 * sizeof(void*)
         && sizeof(ZSTDMT_RustFreeCCtxState) == 13 * sizeof(void*)) ? 1 : -1];
size_t ZSTDMT_rust_freeCCtx(const ZSTDMT_RustFreeCCtxState* state);

typedef struct {
    void* callbackContext;
    unsigned requestedNbWorkers;
    unsigned maxNbWorkers;
    size_t contextSize;
    ZSTD_customMem customMem;
} ZSTDMT_RustCreateCCtxProjection;
typedef char ZSTDMT_rust_create_cctx_projection_layout[
        (offsetof(ZSTDMT_RustCreateCCtxProjection, callbackContext) == 0
         && offsetof(ZSTDMT_RustCreateCCtxProjection, requestedNbWorkers)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustCreateCCtxProjection, maxNbWorkers)
                == sizeof(void*) + sizeof(unsigned)
         && offsetof(ZSTDMT_RustCreateCCtxProjection, contextSize)
                == (sizeof(void*) == 8 ? 16 : 12)
         && offsetof(ZSTDMT_RustCreateCCtxProjection, customMem)
                == (sizeof(void*) == 8 ? 24 : 16)
         && sizeof(ZSTDMT_RustCreateCCtxProjection)
                == (sizeof(void*) == 8 ? 48 : 28)) ? 1 : -1];
typedef void* (*ZSTDMT_createCCtxAllocateFn)(void* opaque, size_t size);
typedef size_t (*ZSTDMT_createCCtxSetWorkersFn)(void* opaque, unsigned nbWorkers);
typedef void (*ZSTDMT_createCCtxSetInitialStateFn)(void* opaque);
typedef void* (*ZSTDMT_createCCtxFactoryFn)(void* opaque, unsigned nbWorkers);
typedef void* (*ZSTDMT_createCCtxJobsFn)(void* opaque, unsigned* nbJobs);
typedef void* (*ZSTDMT_createCCtxResourceFn)(void* opaque, unsigned nbWorkers);
typedef int (*ZSTDMT_createCCtxSerialInitFn)(void* opaque);
typedef void (*ZSTDMT_createCCtxFreeFn)(void* opaque);
void* ZSTDMT_rust_createCCtx(
        const ZSTDMT_RustCreateCCtxProjection* projection,
        ZSTDMT_createCCtxAllocateFn allocate,
        ZSTDMT_createCCtxSetWorkersFn setWorkers,
        ZSTDMT_createCCtxSetInitialStateFn setInitialState,
        ZSTDMT_createCCtxFactoryFn createFactory,
        ZSTDMT_createCCtxJobsFn createJobs,
        ZSTDMT_createCCtxResourceFn createBufferPool,
        ZSTDMT_createCCtxResourceFn createCCtxPool,
        ZSTDMT_createCCtxResourceFn createSeqPool,
        ZSTDMT_createCCtxSerialInitFn initSerial,
        ZSTDMT_createCCtxFreeFn freeContext);
size_t ZSTDMT_rust_initCStream(
        const ZSTDMT_RustInitCStreamProjection* projection, void* opaque,
        ZSTDMT_initResizeFn resize,
        ZSTDMT_initWaitForAllJobsFn waitForAllJobs,
        ZSTDMT_initReleaseAllJobResourcesFn releaseAllJobResources,
        ZSTDMT_initApplyParametersFn applyParameters,
        ZSTDMT_initDictionaryFn prepareDictionary,
        ZSTDMT_initSetSizeFn setTargetPrefixSize,
        ZSTDMT_initSetSizeFn setTargetSectionSize,
        ZSTDMT_initSetRsyncFn setRsync,
        ZSTDMT_initSetBufferSizeFn setBufferSize,
        ZSTDMT_initResizeRoundBufferFn resizeRoundBuffer,
        ZSTDMT_initResetStreamFn resetStream,
        ZSTDMT_initDictionaryFn updateDictionary,
        ZSTDMT_initSerialResetFn serialReset);
size_t ZSTDMT_rust_initSerialResetResult(int status);
typedef void (*ZSTDMT_resetStreamCallbackFn)(void* opaque);
typedef struct {
    void* callbackContext;
    ZSTDMT_resetStreamCallbackFn resetRoundBuffer;
    ZSTDMT_resetStreamCallbackFn resetInputBuffer;
    ZSTDMT_resetStreamCallbackFn resetJobIDs;
    ZSTDMT_resetStreamCallbackFn resetFrameFlags;
    ZSTDMT_resetStreamCallbackFn resetProgress;
} ZSTDMT_RustResetStreamState;
typedef char ZSTDMT_rust_reset_stream_state_layout[
        (sizeof(ZSTDMT_resetStreamCallbackFn) == sizeof(void*)
         && offsetof(ZSTDMT_RustResetStreamState, callbackContext) == 0
         && offsetof(ZSTDMT_RustResetStreamState, resetRoundBuffer) == sizeof(void*)
         && offsetof(ZSTDMT_RustResetStreamState, resetInputBuffer) == 2 * sizeof(void*)
         && offsetof(ZSTDMT_RustResetStreamState, resetJobIDs) == 3 * sizeof(void*)
         && offsetof(ZSTDMT_RustResetStreamState, resetFrameFlags) == 4 * sizeof(void*)
         && offsetof(ZSTDMT_RustResetStreamState, resetProgress) == 5 * sizeof(void*)
         && sizeof(ZSTDMT_RustResetStreamState) == 6 * sizeof(void*)) ? 1 : -1];
void ZSTDMT_rust_resetStream(const ZSTDMT_RustResetStreamState* state);
typedef struct {
    void* callbackContext;
    unsigned nbWorkers;
} ZSTDMT_RustResizeProjection;
typedef char ZSTDMT_rust_resize_projection_layout[
        (offsetof(ZSTDMT_RustResizeProjection, callbackContext) == 0
         && offsetof(ZSTDMT_RustResizeProjection, nbWorkers) == sizeof(void*)
         && sizeof(ZSTDMT_RustResizeProjection)
                == (sizeof(void*) == 8 ? 16 : 8)) ? 1 : -1];
typedef size_t (*ZSTDMT_resizeStepFn)(void* opaque, unsigned nbWorkers);
typedef void* (*ZSTDMT_resizeResourceFn)(void* opaque, unsigned nbWorkers);
size_t ZSTDMT_rust_resize(
        const ZSTDMT_RustResizeProjection* projection,
        ZSTDMT_resizeStepFn resizeFactory,
        ZSTDMT_resizeStepFn expandJobs,
        ZSTDMT_resizeResourceFn expandBufferPool,
        ZSTDMT_resizeResourceFn expandCCtxPool,
        ZSTDMT_resizeResourceFn expandSeqPool,
        ZSTDMT_resizeStepFn setNbWorkers);
typedef struct {
    size_t consumed;
    size_t cSize;
    const void* srcStart;
    size_t srcSize;
    const void* prefixStart;
    size_t prefixSize;
    size_t dstFlushed;
} ZSTDMT_RustJobProjection;
typedef struct {
    const void* start;
    size_t size;
} ZSTDMT_RustInputRange;
typedef struct {
    const void* roundBufferStart;
    size_t roundBufferCapacity;
    size_t roundBufferPos;
    const void* prefixStart;
    size_t prefixSize;
    size_t targetSectionSize;
    const void* inUseStart;
    size_t inUseSize;
} ZSTDMT_RustTryGetInputRangeProjection;
typedef struct {
    unsigned ready;
    unsigned movePrefix;
    void* bufferStart;
    size_t bufferCapacity;
    size_t roundBufferPos;
} ZSTDMT_RustTryGetInputRangeResult;
typedef char ZSTDMT_rust_try_get_input_range_result_layout[
        (offsetof(ZSTDMT_RustTryGetInputRangeResult, ready) == 0
         && offsetof(ZSTDMT_RustTryGetInputRangeResult, movePrefix)
                == sizeof(unsigned)
         && offsetof(ZSTDMT_RustTryGetInputRangeResult, bufferStart)
                == 2 * sizeof(unsigned)
         && offsetof(ZSTDMT_RustTryGetInputRangeResult, bufferCapacity)
                == 2 * sizeof(unsigned) + sizeof(void*)
         && offsetof(ZSTDMT_RustTryGetInputRangeResult, roundBufferPos)
                == 2 * sizeof(unsigned) + sizeof(void*) + sizeof(size_t)
         && sizeof(ZSTDMT_RustTryGetInputRangeResult)
                == 2 * sizeof(unsigned) + sizeof(void*) + 2 * sizeof(size_t))
        ? 1 : -1];
typedef void (*ZSTDMT_jobProjectionFn)(void* opaque, unsigned jobID,
                                      ZSTDMT_RustJobProjection* projection);
ZSTDMT_RustInputRange ZSTDMT_rust_getInputDataInUse(
        unsigned firstJobID, unsigned lastJobID, unsigned jobIDMask,
        size_t roundBufferCapacity, size_t targetSectionSize,
        void* opaque, ZSTDMT_jobProjectionFn projectJob);
ZSTDMT_RustTryGetInputRangeResult ZSTDMT_rust_tryGetInputRange(
        const ZSTDMT_RustTryGetInputRangeProjection* projection);
typedef void (*ZSTDMT_inputRangeWaitFn)(
        void* opaque, void* bufferStart, size_t bufferCapacity);
typedef void (*ZSTDMT_inputRangeMovePrefixFn)(
        void* opaque, void* destination, const void* source, size_t size,
        size_t roundBufferPos);
typedef void (*ZSTDMT_inputRangePublishBufferFn)(
        void* opaque, void* bufferStart, size_t bufferCapacity);
int ZSTDMT_rust_commitInputRange(
        const ZSTDMT_RustTryGetInputRangeResult* result,
        void* roundBufferStart, const void* prefixStart, size_t prefixSize,
        void* opaque, ZSTDMT_inputRangeWaitFn waitForLdm,
        ZSTDMT_inputRangeMovePrefixFn movePrefix,
        ZSTDMT_inputRangePublishBufferFn publishBuffer);
size_t ZSTDMT_rust_toFlushNow(unsigned doneJobID, unsigned nextJobID,
                              unsigned jobIDMask, void* opaque,
                              ZSTDMT_jobProjectionFn projectJob);
size_t ZSTDMT_rust_sizeofCCtx(size_t mtctxSize, size_t factorySize,
                              size_t bufferPoolSize, size_t jobsSize,
                              size_t cctxPoolSize, size_t seqPoolSize,
                              size_t cdictSize, size_t roundBuffSize);
ZSTD_frameProgression ZSTDMT_rust_frameProgression(
        unsigned long long consumed, size_t inBuffFilled,
        unsigned long long produced, unsigned currentJobID);
ZSTD_frameProgression ZSTDMT_rust_frameProgressionAddJob(
        ZSTD_frameProgression progression, size_t srcSize, size_t consumed,
        size_t produced, size_t flushed);
ZSTD_frameProgression ZSTDMT_rust_frameProgressionWithJobs(
        unsigned long long consumed, size_t inBuffFilled,
        unsigned long long produced, unsigned currentJobID,
        unsigned doneJobID, unsigned nextJobID, unsigned jobReady,
        unsigned jobIDMask, void* opaque, ZSTDMT_jobProjectionFn projectJob);
typedef int (*ZSTDMT_jobTableInitFn)(void* jobTable, unsigned nbJobs,
                                     size_t jobSize);
typedef void (*ZSTDMT_jobTableDestroyFn)(void* jobTable, unsigned nbJobs,
                                         size_t jobSize);
typedef struct {
    void* jobTable;
    unsigned nbJobs;
    size_t jobSize;
    ZSTD_customMem cMem;
    ZSTDMT_jobTableDestroyFn destroySync;
} ZSTDMT_RustFreeJobsTableProjection;
typedef char ZSTDMT_rust_free_jobs_table_projection_layout[
        (sizeof(ZSTDMT_jobTableDestroyFn) == sizeof(void*)
         && offsetof(ZSTDMT_RustFreeJobsTableProjection, jobTable) == 0
         && offsetof(ZSTDMT_RustFreeJobsTableProjection, nbJobs)
                == sizeof(void*)
         && offsetof(ZSTDMT_RustFreeJobsTableProjection, jobSize)
                == (sizeof(void*) == 8 ? 16 : 8)
         && offsetof(ZSTDMT_RustFreeJobsTableProjection, cMem)
                == offsetof(ZSTDMT_RustFreeJobsTableProjection, jobSize)
                        + sizeof(size_t)
         && offsetof(ZSTDMT_RustFreeJobsTableProjection, destroySync)
                == offsetof(ZSTDMT_RustFreeJobsTableProjection, cMem)
                        + sizeof(ZSTD_customMem)
         && sizeof(ZSTDMT_RustFreeJobsTableProjection)
                == offsetof(ZSTDMT_RustFreeJobsTableProjection, destroySync)
                        + sizeof(ZSTDMT_jobTableDestroyFn))
        ? 1 : -1];
void* ZSTDMT_rust_createJobsTable(
        unsigned* nbJobsPtr, size_t jobSize, ZSTD_customMem cMem,
        ZSTDMT_jobTableInitFn initSync, ZSTDMT_jobTableDestroyFn destroySync);
size_t ZSTDMT_rust_expandJobsTable(
        void** jobTablePtr, unsigned* jobIDMaskPtr, unsigned nbWorkers,
        size_t jobSize, ZSTD_customMem cMem,
        ZSTDMT_jobTableInitFn initSync,
        ZSTDMT_jobTableDestroyFn destroySync);
void ZSTDMT_rust_freeJobsTable(
        const ZSTDMT_RustFreeJobsTableProjection* projection);

typedef struct ZSTDMT_bufferPool_s {
    ZSTDMT_RustBufferPool* rustPool;
    ZSTD_customMem cMem;
} ZSTDMT_bufferPool;

static void ZSTDMT_freeBufferPool(ZSTDMT_bufferPool* bufPool)
{
    if (!bufPool) return;   /* compatibility with free on NULL */
    ZSTDMT_rust_buffer_pool_free(bufPool->rustPool);
    ZSTD_customFree(bufPool, bufPool->cMem);
}

static ZSTDMT_bufferPool* ZSTDMT_createBufferPool(unsigned maxNbBuffers, ZSTD_customMem cMem)
{
    ZSTDMT_bufferPool* const bufPool =
        (ZSTDMT_bufferPool*)ZSTD_customCalloc(sizeof(ZSTDMT_bufferPool), cMem);
    if (bufPool==NULL) return NULL;
    bufPool->rustPool = ZSTDMT_rust_buffer_pool_create(maxNbBuffers, cMem);
    if (bufPool->rustPool == NULL) {
        ZSTD_customFree(bufPool, cMem);
        return NULL;
    }
    bufPool->cMem = cMem;
    return bufPool;
}

/* only works at initialization, not during compression */
static size_t ZSTDMT_sizeof_bufferPool(ZSTDMT_bufferPool* bufPool)
{
    if (bufPool == NULL) return 0;
    return ZSTDMT_rust_sizeofBufferPool(
        sizeof(*bufPool), ZSTDMT_rust_buffer_pool_sizeof(bufPool->rustPool));
}

/* ZSTDMT_setBufferSize() :
 * all future buffers provided by this buffer pool will have _at least_ this size
 * note : it's better for all buffers to have same size,
 * as they become freely interchangeable, reducing malloc/free usages and memory fragmentation */
static void ZSTDMT_setBufferSize(ZSTDMT_bufferPool* const bufPool, size_t const bSize)
{
    DEBUGLOG(4, "ZSTDMT_setBufferSize: bSize = %u", (U32)bSize);
    ZSTDMT_rust_buffer_pool_set_size(bufPool->rustPool, bSize);
}


static ZSTDMT_bufferPool* ZSTDMT_expandBufferPool(ZSTDMT_bufferPool* srcBufPool, unsigned maxNbBuffers)
{
    if (srcBufPool==NULL) return NULL;
    srcBufPool->rustPool = ZSTDMT_rust_buffer_pool_expand(srcBufPool->rustPool, maxNbBuffers);
    if (srcBufPool->rustPool == NULL) {
        ZSTD_customMem const cMem = srcBufPool->cMem;
        ZSTD_customFree(srcBufPool, cMem);
        return NULL;
    }
    return srcBufPool;
}

/** ZSTDMT_getBuffer() :
 *  assumption : bufPool must be valid
 * @return : a buffer, with start pointer and size
 *  note: allocation may fail, in this case, start==NULL and size==0 */
static Buffer ZSTDMT_getBuffer(ZSTDMT_bufferPool* bufPool)
{
    ZSTDMT_RustBuffer const rustBuffer =
        ZSTDMT_rust_buffer_pool_get(bufPool->rustPool);
    Buffer buffer = { rustBuffer.start, rustBuffer.capacity };
    return buffer;
}

static ZSTDMT_RustBuffer ZSTDMT_getBufferForRust(void* opaque)
{
    Buffer const buffer = ZSTDMT_getBuffer((ZSTDMT_bufferPool*)opaque);
    ZSTDMT_RustBuffer const result = { buffer.start, buffer.capacity };
    return result;
}

#if ZSTD_RESIZE_SEQPOOL
/** ZSTDMT_resizeBuffer() :
 * assumption : bufPool must be valid
 * @return : a buffer that is at least the buffer pool buffer size.
 *           If a reallocation happens, the data in the input buffer is copied.
 */
static Buffer ZSTDMT_resizeBuffer(ZSTDMT_bufferPool* bufPool, Buffer buffer)
{
    ZSTDMT_RustBuffer const rustBuffer = { buffer.start, buffer.capacity };
    ZSTDMT_RustBuffer const resized =
        ZSTDMT_rust_buffer_pool_resize(bufPool->rustPool, rustBuffer);
    Buffer const result = { resized.start, resized.capacity };
    return result;
}
#endif

/* store buffer for later re-use, up to pool capacity */
static void ZSTDMT_releaseBuffer(ZSTDMT_bufferPool* bufPool, Buffer buf)
{
    ZSTDMT_RustBuffer const rustBuffer = { buf.start, buf.capacity };
    ZSTDMT_rust_buffer_pool_release(bufPool->rustPool, rustBuffer);
}

/* We need 2 output buffers per worker since each dstBuff must be flushed after it is released.
 * The 3 additional buffers are as follows:
 *   1 buffer for input loading
 *   1 buffer for "next input" when submitting current one
 *   1 buffer stuck in queue */
#define BUF_POOL_MAX_NB_BUFFERS(nbWorkers) (2*(nbWorkers) + 3)

/* After a worker releases its rawSeqStore, it is immediately ready for reuse.
 * So we only need one seq buffer per worker. */
#define SEQ_POOL_MAX_NB_BUFFERS(nbWorkers) (nbWorkers)

/* =====   Seq Pool Wrapper   ====== */

typedef ZSTDMT_bufferPool ZSTDMT_seqPool;

static size_t ZSTDMT_sizeof_seqPool(ZSTDMT_seqPool* seqPool)
{
    return ZSTDMT_sizeof_bufferPool(seqPool);
}

static RawSeqStore_t bufferToSeq(Buffer buffer)
{
    ZSTDMT_RustRawSeqStore const rustSeq =
        ZSTDMT_rust_bufferToSeq((ZSTDMT_RustBuffer){ buffer.start, buffer.capacity });
    RawSeqStore_t seq = {
        (rawSeq*)rustSeq.seq,
        rustSeq.pos,
        rustSeq.posInSequence,
        rustSeq.size,
        rustSeq.capacity
    };
    return seq;
}

static Buffer seqToBuffer(RawSeqStore_t seq)
{
    ZSTDMT_RustRawSeqStore const rustSeq = {
        seq.seq,
        seq.pos,
        seq.posInSequence,
        seq.size,
        seq.capacity
    };
    ZSTDMT_RustBuffer const rustBuffer = ZSTDMT_rust_seqToBuffer(rustSeq);
    return (Buffer){ rustBuffer.start, rustBuffer.capacity };
}

static RawSeqStore_t ZSTDMT_getSeq(ZSTDMT_seqPool* seqPool)
{
    return bufferToSeq(ZSTDMT_getBuffer(seqPool));
}

#if ZSTD_RESIZE_SEQPOOL
static RawSeqStore_t ZSTDMT_resizeSeq(ZSTDMT_seqPool* seqPool, RawSeqStore_t seq)
{
  return bufferToSeq(ZSTDMT_resizeBuffer(seqPool, seqToBuffer(seq)));
}
#endif

static void ZSTDMT_releaseSeq(ZSTDMT_seqPool* seqPool, RawSeqStore_t seq)
{
  ZSTDMT_releaseBuffer(seqPool, seqToBuffer(seq));
}

static void ZSTDMT_setNbSeq(ZSTDMT_seqPool* const seqPool, size_t const nbSeq)
{
  ZSTDMT_setBufferSize(seqPool, nbSeq * sizeof(rawSeq));
}

static ZSTDMT_seqPool* ZSTDMT_createSeqPool(unsigned nbWorkers, ZSTD_customMem cMem)
{
    ZSTDMT_seqPool* const seqPool = ZSTDMT_createBufferPool(SEQ_POOL_MAX_NB_BUFFERS(nbWorkers), cMem);
    if (seqPool == NULL) return NULL;
    ZSTDMT_setNbSeq(seqPool, 0);
    return seqPool;
}

static void ZSTDMT_freeSeqPool(ZSTDMT_seqPool* seqPool)
{
    ZSTDMT_freeBufferPool(seqPool);
}

static ZSTDMT_seqPool* ZSTDMT_expandSeqPool(ZSTDMT_seqPool* pool, U32 nbWorkers)
{
    return ZSTDMT_expandBufferPool(pool, SEQ_POOL_MAX_NB_BUFFERS(nbWorkers));
}


/* =====   CCtx Pool   ===== */
/* a single CCtx Pool can be invoked from multiple threads in parallel */

typedef struct ZSTDMT_RustCCtxPool_s ZSTDMT_RustCCtxPool;

ZSTDMT_RustCCtxPool* ZSTDMT_rust_cctx_pool_create(unsigned nbWorkers,
                                                   ZSTD_customMem cMem);
void ZSTDMT_rust_cctx_pool_free(ZSTDMT_RustCCtxPool* pool);
size_t ZSTDMT_rust_cctx_pool_sizeof(const ZSTDMT_RustCCtxPool* pool);
size_t ZSTDMT_rust_sizeofCCtxPool(size_t wrapperSize, size_t rustPoolSize);
ZSTDMT_RustCCtxPool* ZSTDMT_rust_cctx_pool_expand(ZSTDMT_RustCCtxPool* pool,
                                                   unsigned nbWorkers);
ZSTD_CCtx* ZSTDMT_rust_cctx_pool_get(ZSTDMT_RustCCtxPool* pool);
void ZSTDMT_rust_cctx_pool_release(ZSTDMT_RustCCtxPool* pool, ZSTD_CCtx* cctx);

typedef struct {
    ZSTDMT_RustCCtxPool* rustPool;
    int totalCCtx; /* kept for the existing MT parameter diagnostics */
    ZSTD_customMem cMem;
} ZSTDMT_CCtxPool;

/* note : all CCtx borrowed from the pool must be reverted back to the pool _before_ freeing the pool */
static void ZSTDMT_freeCCtxPool(ZSTDMT_CCtxPool* pool)
{
    if (!pool) return;
    ZSTDMT_rust_cctx_pool_free(pool->rustPool);
    ZSTD_customFree(pool, pool->cMem);
}

/* ZSTDMT_createCCtxPool() :
 * implies nbWorkers >= 1 , checked by caller ZSTDMT_createCCtx() */
static ZSTDMT_CCtxPool* ZSTDMT_createCCtxPool(int nbWorkers,
                                              ZSTD_customMem cMem)
{
    ZSTDMT_CCtxPool* const cctxPool =
        (ZSTDMT_CCtxPool*) ZSTD_customCalloc(sizeof(ZSTDMT_CCtxPool), cMem);
    assert(nbWorkers > 0);
    if (!cctxPool) return NULL;
    cctxPool->rustPool = ZSTDMT_rust_cctx_pool_create((unsigned)nbWorkers, cMem);
    if (cctxPool->rustPool == NULL) {
        ZSTD_customFree(cctxPool, cMem);
        return NULL;
    }
    cctxPool->totalCCtx = nbWorkers;
    cctxPool->cMem = cMem;
    DEBUGLOG(3, "cctxPool created, with %u workers", nbWorkers);
    return cctxPool;
}

static ZSTDMT_CCtxPool* ZSTDMT_expandCCtxPool(ZSTDMT_CCtxPool* srcPool,
                                              int nbWorkers)
{
    if (srcPool==NULL) return NULL;
    srcPool->rustPool = ZSTDMT_rust_cctx_pool_expand(srcPool->rustPool,
                                                      (unsigned)nbWorkers);
    if (srcPool->rustPool == NULL) {
        ZSTD_customMem const cMem = srcPool->cMem;
        ZSTD_customFree(srcPool, cMem);
        return NULL;
    }
    srcPool->totalCCtx = nbWorkers;
    return srcPool;
}

/* only works during initialization phase, not during compression */
static size_t ZSTDMT_sizeof_CCtxPool(ZSTDMT_CCtxPool* cctxPool)
{
    size_t rustPoolSize;
    if (cctxPool == NULL) return 0;
    rustPoolSize = ZSTDMT_rust_cctx_pool_sizeof(cctxPool->rustPool);
    return ZSTDMT_rust_sizeofCCtxPool(sizeof(*cctxPool), rustPoolSize);
}

static ZSTD_CCtx* ZSTDMT_getCCtx(ZSTDMT_CCtxPool* cctxPool)
{
    DEBUGLOG(5, "ZSTDMT_getCCtx");
    return ZSTDMT_rust_cctx_pool_get(cctxPool->rustPool);
}

static void ZSTDMT_releaseCCtx(ZSTDMT_CCtxPool* pool, ZSTD_CCtx* cctx)
{
    ZSTDMT_rust_cctx_pool_release(pool->rustPool, cctx);
}

/* ====   Serial State   ==== */

typedef struct {
    void const* start;
    size_t size;
} Range;

typedef struct {
    /* All variables in the struct are protected by mutex. */
    ZSTD_pthread_mutex_t mutex;
    ZSTD_pthread_cond_t cond;
    ZSTD_CCtx_params params;
    ldmState_t ldmState;
    XXH64_state_t xxhState;
    unsigned nextJobID;
    /* Protects ldmWindow.
     * Must be acquired after the main mutex when acquiring both.
     */
    ZSTD_pthread_mutex_t ldmWindowMutex;
    ZSTD_pthread_cond_t ldmWindowCond;  /* Signaled when ldmWindow is updated */
    ZSTD_window_t ldmWindow;  /* A thread-safe copy of ldmState.window */
} SerialState;

typedef struct {
    SerialState* serialState;
    ZSTDMT_seqPool* seqPool;
    ZSTD_CCtx_params* params;
    const void* dict;
    size_t dictSize;
    ZSTD_dictContentType_e dictContentType;
    ZSTD_customMem cMem;
} ZSTDMT_serialResetContext;

static void ZSTDMT_serialResetSetLdmParams(
        void* opaque, int enableLdm, unsigned hashLog,
        unsigned bucketSizeLog, unsigned minMatchLength,
        unsigned hashRateLog, unsigned windowLog)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    ldmParams_t* const ldmParams = &context->params->ldmParams;
    ldmParams->enableLdm = (ZSTD_ParamSwitch_e)enableLdm;
    ldmParams->hashLog = hashLog;
    ldmParams->bucketSizeLog = bucketSizeLog;
    ldmParams->minMatchLength = minMatchLength;
    ldmParams->hashRateLog = hashRateLog;
    ldmParams->windowLog = windowLog;
}

static void ZSTDMT_serialResetNextJob(void* opaque)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    context->serialState->nextJobID = 0;
}

static void ZSTDMT_serialResetChecksum(void* opaque)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    XXH64_reset(&context->serialState->xxhState, 0);
}

static void ZSTDMT_serialResetSetNbSeq(void* opaque, size_t nbSeq)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    ZSTDMT_setNbSeq(context->seqPool, nbSeq);
}

static void ZSTDMT_serialResetWindow(void* opaque)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    ZSTD_window_init(&context->serialState->ldmState.window);
}

static int ZSTDMT_serialResetResizeTables(
        void* opaque, size_t hashSize, size_t numBuckets,
        unsigned bucketLog, unsigned previousBucketLog)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    SerialState* const serialState = context->serialState;
    ldmParams_t const* const ldmParams = &context->params->ldmParams;

    if (serialState->ldmState.hashTable == NULL ||
            serialState->params.ldmParams.hashLog < ldmParams->hashLog) {
        ZSTD_customFree(serialState->ldmState.hashTable, context->cMem);
        serialState->ldmState.hashTable = (ldmEntry_t*)ZSTD_customMalloc(
                hashSize, context->cMem);
    }
    if (serialState->ldmState.bucketOffsets == NULL ||
            previousBucketLog < bucketLog) {
        ZSTD_customFree(serialState->ldmState.bucketOffsets, context->cMem);
        serialState->ldmState.bucketOffsets = (BYTE*)ZSTD_customMalloc(
                numBuckets, context->cMem);
    }
    return !serialState->ldmState.hashTable || !serialState->ldmState.bucketOffsets;
}

static void ZSTDMT_serialResetZeroTables(
        void* opaque, size_t hashSize, size_t numBuckets)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    SerialState* const serialState = context->serialState;
    ZSTD_memset(serialState->ldmState.hashTable, 0, hashSize);
    ZSTD_memset(serialState->ldmState.bucketOffsets, 0, numBuckets);
}

static size_t ZSTDMT_serialResetLoadRawDictionary(
        void* opaque, const void* dict, size_t dictSize)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    SerialState* const serialState = context->serialState;
    BYTE const* const dictEnd = (const BYTE*)dict + dictSize;

    ZSTD_window_update(&serialState->ldmState.window,
                       dict, dictSize,
                       /* forceNonContiguous */ 0);
    ZSTD_ldm_fillHashTable(&serialState->ldmState,
                           (const BYTE*)dict, dictEnd,
                           &context->params->ldmParams);
    return (size_t)(dictEnd - serialState->ldmState.window.base);
}

static void ZSTDMT_serialResetSetLoadedDictEnd(
        void* opaque, U32 loadedDictEnd)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    context->serialState->ldmState.loadedDictEnd = loadedDictEnd;
}

static void ZSTDMT_serialResetLoadDictionary(void* opaque)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    ZSTDMT_RustSerialDictionaryProjection const projection = {
        context->dict,
        context->dictSize,
        (int)context->dictContentType,
        context->params->forceWindow
    };
    ZSTDMT_rust_serialStateLoadDictionary(
            &projection, context,
            ZSTDMT_serialResetLoadRawDictionary,
            ZSTDMT_serialResetSetLoadedDictEnd);
}

static void ZSTDMT_serialResetCopyWindow(void* opaque)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    context->serialState->ldmWindow = context->serialState->ldmState.window;
}

static void ZSTDMT_serialResetPublishParams(void* opaque, size_t jobSize)
{
    ZSTDMT_serialResetContext* const context = (ZSTDMT_serialResetContext*)opaque;
    context->serialState->params = *context->params;
    context->serialState->params.jobSize = (U32)jobSize;
}

static int
ZSTDMT_serialState_reset(SerialState* serialState,
                         ZSTDMT_seqPool* seqPool,
                         ZSTD_CCtx_params params,
                         size_t jobSize,
                         const void* dict, size_t const dictSize,
                         ZSTD_dictContentType_e dictContentType)
{
    ZSTDMT_serialResetContext context;
    ZSTDMT_RustSerialResetProjection const projection = {
        params.ldmParams.enableLdm,
        params.fParams.checksumFlag,
        jobSize,
        params.cParams.windowLog,
        params.cParams.strategy,
        params.ldmParams.hashLog,
        params.ldmParams.bucketSizeLog,
        params.ldmParams.minMatchLength,
        params.ldmParams.hashRateLog,
        serialState->params.ldmParams.hashLog,
        serialState->params.ldmParams.bucketSizeLog,
        sizeof(ldmEntry_t)
    };

    /* Rust owns LDM normalization; retain the original diagnostic only. */
    if (params.ldmParams.enableLdm == ZSTD_ps_enable) {
        DEBUGLOG(4, "LDM window size = %u KB", (1U << params.cParams.windowLog) >> 10);
    }

    context.serialState = serialState;
    context.seqPool = seqPool;
    context.params = &params;
    context.dict = dict;
    context.dictSize = dictSize;
    context.dictContentType = dictContentType;
    context.cMem = params.customMem;

    if (ZSTDMT_rust_serialStateReset(
            &projection, &context,
            ZSTDMT_serialResetSetLdmParams,
            ZSTDMT_serialResetNextJob,
            ZSTDMT_serialResetChecksum,
            ZSTDMT_serialResetSetNbSeq,
            ZSTDMT_serialResetWindow,
            ZSTDMT_serialResetResizeTables,
            ZSTDMT_serialResetZeroTables,
            ZSTDMT_serialResetLoadDictionary,
            ZSTDMT_serialResetCopyWindow,
            ZSTDMT_serialResetPublishParams)) {
        return 1;
    }
    return 0;
}

static void ZSTDMT_serialState_zero(void* opaque)
{
    ZSTD_memset(opaque, 0, sizeof(SerialState));
}

static int ZSTDMT_serialState_initMutex(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    return ZSTD_pthread_mutex_init(&serialState->mutex, NULL);
}

static int ZSTDMT_serialState_initCond(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    return ZSTD_pthread_cond_init(&serialState->cond, NULL);
}

static int ZSTDMT_serialState_initLdmMutex(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    return ZSTD_pthread_mutex_init(&serialState->ldmWindowMutex, NULL);
}

static int ZSTDMT_serialState_initLdmCond(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    return ZSTD_pthread_cond_init(&serialState->ldmWindowCond, NULL);
}

static void ZSTDMT_serialState_destroyMutex(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_mutex_destroy(&serialState->mutex);
}

static void ZSTDMT_serialState_destroyCond(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_cond_destroy(&serialState->cond);
}

static void ZSTDMT_serialState_destroyLdmMutex(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_mutex_destroy(&serialState->ldmWindowMutex);
}

static void ZSTDMT_serialState_destroyLdmCond(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_cond_destroy(&serialState->ldmWindowCond);
}

static void ZSTDMT_serialState_freeTables(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_customMem const cMem = serialState->params.customMem;
    ZSTD_customFree(serialState->ldmState.hashTable, cMem);
    ZSTD_customFree(serialState->ldmState.bucketOffsets, cMem);
}

static int ZSTDMT_serialState_init(SerialState* serialState)
{
    return ZSTDMT_rust_serialStateInit(
            serialState,
            ZSTDMT_serialState_zero,
            ZSTDMT_serialState_initMutex,
            ZSTDMT_serialState_initCond,
            ZSTDMT_serialState_initLdmMutex,
            ZSTDMT_serialState_initLdmCond);
}

static void ZSTDMT_serialState_free(SerialState* serialState)
{
    ZSTDMT_rust_serialStateFree(
            serialState,
            ZSTDMT_serialState_destroyMutex,
            ZSTDMT_serialState_destroyCond,
            ZSTDMT_serialState_destroyLdmMutex,
            ZSTDMT_serialState_destroyLdmCond,
            ZSTDMT_serialState_freeTables);
}

static void ZSTDMT_serialState_lock(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_PTHREAD_MUTEX_LOCK(&serialState->mutex);
}

static void ZSTDMT_serialState_wait(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    DEBUGLOG(5, "wait for serialState->cond");
    ZSTD_pthread_cond_wait(&serialState->cond, &serialState->mutex);
}

static void ZSTDMT_serialState_broadcast(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_cond_broadcast(&serialState->cond);
}

static void ZSTDMT_serialState_unlock(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_mutex_unlock(&serialState->mutex);
}

/* Rust owns the serial turn/skip decision and operation ordering.  The wait
 * callback intentionally leaves the main serial mutex locked; the advance
 * callback releases it after Rust has performed the current turn's work. */
static int ZSTDMT_serialState_waitForTurn(void* opaque, unsigned jobID)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTDMT_RustSerialWaitForTurnState state;
    state.callbackContext = serialState;
    state.nextJobID = &serialState->nextJobID;
    state.lock = ZSTDMT_serialState_lock;
    state.wait = ZSTDMT_serialState_wait;
    state.jobID = jobID;
    return ZSTDMT_rust_serialStateWaitForTurn(&state);
}

static void ZSTDMT_serialState_updateLdmWindow(
        void* opaque, ZSTDMT_RustRawSeqStore* seqStore,
        const void* src, size_t srcSize)
{
    SerialState* const serialState = (SerialState*)opaque;
    RawSeqStore_t* const cSeqStore = (RawSeqStore_t*)seqStore;

    DEBUGLOG(6, "ZSTDMT_serialState_genSequences: LDM update");
    assert(cSeqStore->seq != NULL && cSeqStore->pos == 0 &&
           cSeqStore->size == 0 && cSeqStore->capacity > 0);
    assert(srcSize <= serialState->params.jobSize);
    ZSTD_window_update(&serialState->ldmState.window, src, srcSize,
                       /* forceNonContiguous */ 0);
}

static void ZSTDMT_serialState_generateLdmSequences(
        void* opaque, ZSTDMT_RustRawSeqStore* seqStore,
        const void* src, size_t srcSize)
{
    SerialState* const serialState = (SerialState*)opaque;
    RawSeqStore_t* const cSeqStore = (RawSeqStore_t*)seqStore;
    size_t error;

    error = ZSTD_ldm_generateSequences(
        &serialState->ldmState, cSeqStore,
        &serialState->params.ldmParams, src, srcSize);
    /* We provide a large enough buffer to never fail. */
    assert(!ZSTD_isError(error)); (void)error;
}

static void ZSTDMT_serialState_publishLdmWindow(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;

    /* Update ldmWindow to match the ldmState.window and signal the main
     * thread if it is waiting for a buffer. */
    ZSTD_PTHREAD_MUTEX_LOCK(&serialState->ldmWindowMutex);
    serialState->ldmWindow = serialState->ldmState.window;
    ZSTD_pthread_cond_signal(&serialState->ldmWindowCond);
    ZSTD_pthread_mutex_unlock(&serialState->ldmWindowMutex);
}

static void ZSTDMT_serialState_advance(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTDMT_RustSerialAdvanceState state;
    state.callbackContext = serialState;
    state.nextJobID = &serialState->nextJobID;
    state.broadcast = ZSTDMT_serialState_broadcast;
    state.unlock = ZSTDMT_serialState_unlock;
    ZSTDMT_rust_serialStateAdvance(&state);
}

static void ZSTDMT_serialState_ldmLock(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_PTHREAD_MUTEX_LOCK(&serialState->ldmWindowMutex);
}

static void ZSTDMT_serialState_clearLdmWindow(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_rust_windowClear((size_t)(serialState->ldmWindow.nextSrc -
                                   serialState->ldmWindow.base),
                          &serialState->ldmWindow.lowLimit,
                          &serialState->ldmWindow.dictLimit);
}

static void ZSTDMT_serialState_ldmSignal(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_cond_signal(&serialState->ldmWindowCond);
}

static void ZSTDMT_serialState_ldmUnlock(void* opaque)
{
    SerialState* const serialState = (SerialState*)opaque;
    ZSTD_pthread_mutex_unlock(&serialState->ldmWindowMutex);
}

static void ZSTDMT_serialState_onSkip(void* opaque, unsigned jobID, size_t cSize)
{
    (void)opaque;
    assert(ZSTD_isError(cSize)); (void)cSize;
    DEBUGLOG(5, "Skipping past job %u because of error", jobID);
}

/* Rust owns the non-empty/LDM gate and the point at which this callback is
 * invoked.  Keep only the private codec operation on the C side. */
static void ZSTDMT_compressionJobReferenceSequences(
        void* opaque, void* cctx, void* sequences, size_t nbSequences)
{
    (void)opaque;
    assert(cctx != NULL);
    DEBUGLOG(5, "ZSTDMT_compressionJob: uploading %u external sequences",
             (unsigned)nbSequences);
    ZSTD_referenceExternalSequences((ZSTD_CCtx*)cctx,
                                    (rawSeq*)sequences, nbSequences);
}

static void ZSTDMT_serialState_ensureFinished(SerialState* serialState,
                                              unsigned jobID, size_t cSize)
{
    ZSTDMT_RustSerialEnsureFinishedState state;
    state.callbackContext = serialState;
    state.nextJobID = &serialState->nextJobID;
    state.lock = ZSTDMT_serialState_lock;
    state.broadcast = ZSTDMT_serialState_broadcast;
    state.ldmLock = ZSTDMT_serialState_ldmLock;
    state.clearLdmWindow = ZSTDMT_serialState_clearLdmWindow;
    state.ldmSignal = ZSTDMT_serialState_ldmSignal;
    state.ldmUnlock = ZSTDMT_serialState_ldmUnlock;
    state.unlock = ZSTDMT_serialState_unlock;
    state.onSkip = ZSTDMT_serialState_onSkip;
    state.cSize = cSize;
    state.jobID = jobID;
    ZSTDMT_rust_serialStateEnsureFinishedOrchestrated(&state);

}


/* ------------------------------------------ */
/* =====          Worker thread         ===== */
/* ------------------------------------------ */

static const Range kNullRange = { NULL, 0 };

typedef struct {
    size_t   consumed;                 /* SHARED - set0 by mtctx, then modified by worker AND read by mtctx */
    size_t   cSize;                    /* SHARED - set0 by mtctx, then modified by worker AND read by mtctx, then set0 by mtctx */
    ZSTD_pthread_mutex_t job_mutex;    /* Thread-safe - used by mtctx and worker */
    ZSTD_pthread_cond_t job_cond;      /* Thread-safe - used by mtctx and worker */
    ZSTDMT_CCtxPool* cctxPool;         /* Thread-safe - used by mtctx and (all) workers */
    ZSTDMT_bufferPool* bufPool;        /* Thread-safe - used by mtctx and (all) workers */
    ZSTDMT_seqPool* seqPool;           /* Thread-safe - used by mtctx and (all) workers */
    SerialState* serial;               /* Thread-safe - used by mtctx and (all) workers */
    Buffer dstBuff;                    /* set by worker (or mtctx), then read by worker & mtctx, then modified by mtctx => no barrier */
    Range prefix;                      /* set by mtctx, then read by worker & mtctx => no barrier */
    Range src;                         /* set by mtctx, then read by worker & mtctx => no barrier */
    unsigned jobID;                    /* set by mtctx, then read by worker => no barrier */
    unsigned firstJob;                 /* set by mtctx, then read by worker => no barrier */
    unsigned lastJob;                  /* set by mtctx, then read by worker => no barrier */
    ZSTD_CCtx_params params;           /* set by mtctx, then read by worker => no barrier */
    const ZSTD_CDict* cdict;           /* set by mtctx, then read by worker => no barrier */
    unsigned long long fullFrameSize;  /* set by mtctx, then read by worker => no barrier */
    size_t   dstFlushed;               /* used only by mtctx */
    unsigned frameChecksumNeeded;      /* used only by mtctx */
} ZSTDMT_jobDescription;

static void ZSTDMT_compressionJobProgressLock(void* opaque)
{
    ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)opaque;
    ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
}

static void ZSTDMT_compressionJobProgressSignal(void* opaque)
{
    ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)opaque;
    ZSTD_pthread_cond_signal(&job->job_cond);   /* warns some more data is ready to be flushed */
}

static void ZSTDMT_compressionJobProgressUnlock(void* opaque)
{
    ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)opaque;
    ZSTD_pthread_mutex_unlock(&job->job_mutex);
}

static void ZSTDMT_compressionJobProgressDebug(
        void* opaque, size_t cSize, size_t totalCSize)
{
    (void)opaque;
    DEBUGLOG(5, "ZSTDMT_compressionJob: compress new block : cSize==%u bytes (total: %u)",
                (U32)cSize, (U32)totalCSize);
}

typedef struct {
    ZSTDMT_jobDescription* job;
    ZSTD_CCtx_params jobParams;
    ZSTD_CCtx* cctx;
    RawSeqStore_t rawSeqStore;
    Buffer dstBuff;
    ZSTDMT_RustCompressionJobFrameHeaderState frameHeaderState;
} ZSTDMT_compressionJobState;

static void ZSTDMT_compressionJobAcquireCCtx(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    state->cctx = ZSTDMT_getCCtx(state->job->cctxPool);
}

static void ZSTDMT_compressionJobAcquireRawSeqStore(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    state->rawSeqStore = ZSTDMT_getSeq(state->job->seqPool);
}

static int ZSTDMT_compressionJobHasCCtx(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    return state->cctx != NULL;
}

static size_t ZSTDMT_compressionJobAcquireDestinationBuffer(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;
    state->dstBuff = ZSTDMT_getBuffer(job->bufPool);
    if (state->dstBuff.start == NULL) return ERROR(memory_allocation);
    job->dstBuff = state->dstBuff;
    return 0;
}

static int ZSTDMT_compressionJobHasRawSeqStore(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    return state->rawSeqStore.seq != NULL;
}

static void ZSTDMT_compressionJobPublishDestination(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    state->frameHeaderState.dst = state->dstBuff.start;
    state->frameHeaderState.dstCapacity = state->dstBuff.capacity;
}

static size_t ZSTDMT_compressionJobAcquireResources(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;
    ZSTDMT_RustCompressionJobResourceProjection const projection = {
        state->jobParams.ldmParams.enableLdm == ZSTD_ps_enable,
        job->dstBuff.start != NULL
    };

    state->dstBuff = job->dstBuff;
    DEBUGLOG(5, "ZSTDMT_compressionJob: job %u", job->jobID);
    return ZSTDMT_rust_compressionJobAcquireResources(
            &projection, state,
            ZSTDMT_compressionJobAcquireCCtx,
            ZSTDMT_compressionJobAcquireRawSeqStore,
            ZSTDMT_compressionJobHasCCtx,
            ZSTDMT_compressionJobAcquireDestinationBuffer,
            ZSTDMT_compressionJobHasRawSeqStore,
            ZSTDMT_compressionJobPublishDestination);
}

static void ZSTDMT_compressionJobPrepareParameters(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;
    ZSTDMT_RustCompressionJobParameters const parameters =
            ZSTDMT_rust_prepareCompressionJobParameters(
                    job->jobID,
                    state->jobParams.fParams.checksumFlag,
                    state->jobParams.ldmParams.enableLdm,
                    (unsigned)state->jobParams.nbWorkers);

    state->jobParams.fParams.checksumFlag = parameters.checksumFlag;
    state->jobParams.ldmParams.enableLdm = parameters.ldmEnable;
    state->jobParams.nbWorkers = (int)parameters.nbWorkers;
}

static void ZSTDMT_compressionJobGenerateSequences(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;

    /* Perform serial step as early as possible. */
    ZSTDMT_rust_serialStateGenSequences(
            (ZSTDMT_RustRawSeqStore*)&state->rawSeqStore,
            job->src.start, job->src.size, job->jobID,
            job->serial->params.ldmParams.enableLdm == ZSTD_ps_enable,
            job->serial->params.fParams.checksumFlag,
            job->serial,
            &job->serial->xxhState,
            ZSTDMT_serialState_waitForTurn,
            ZSTDMT_serialState_updateLdmWindow,
            ZSTDMT_serialState_generateLdmSequences,
            ZSTDMT_serialState_publishLdmWindow,
            ZSTDMT_serialState_advance);
}

static size_t ZSTDMT_compressionJobBeginWithCDict(void* opaque);
static size_t ZSTDMT_compressionJobSetForceMaxWindow(void* opaque, int value);
static size_t ZSTDMT_compressionJobSetDeterministicRefPrefix(void* opaque);
static size_t ZSTDMT_compressionJobBeginWithPrefix(void* opaque);
static void ZSTDMT_compressionJobPublishFrameHeader(void* opaque);

static size_t ZSTDMT_compressionJobBegin(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;

    ZSTDMT_RustCompressionJobBeginProjection const projection = {
        job->firstJob,
        (unsigned)(job->cdict != NULL)
    };
    return ZSTDMT_rust_compressionJobBegin(
            &projection, state,
            ZSTDMT_compressionJobBeginWithCDict,
            ZSTDMT_compressionJobSetForceMaxWindow,
            ZSTDMT_compressionJobSetDeterministicRefPrefix,
            ZSTDMT_compressionJobBeginWithPrefix,
            ZSTDMT_compressionJobPublishFrameHeader);
}

static size_t ZSTDMT_compressionJobBeginWithCDict(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;

    return ZSTD_compressBegin_advanced_internal(
        state->cctx, NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast, job->cdict,
        &state->jobParams, job->fullFrameSize);
}

static size_t ZSTDMT_compressionJobSetForceMaxWindow(void* opaque, int value)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;

    return ZSTD_CCtxParams_setParameter(
            &state->jobParams, ZSTD_c_forceMaxWindow, value);
}

static size_t ZSTDMT_compressionJobSetDeterministicRefPrefix(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;

    return ZSTD_CCtxParams_setParameter(
            &state->jobParams, ZSTD_c_deterministicRefPrefix, 0);
}

static size_t ZSTDMT_compressionJobBeginWithPrefix(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;
    U64 const pledgedSrcSize = job->firstJob ? job->fullFrameSize : job->src.size;

    DEBUGLOG(6, "ZSTDMT_compressionJob: job %u: loading prefix of size %zu", job->jobID, job->prefix.size);
    return ZSTD_compressBegin_advanced_internal(
        state->cctx, job->prefix.start, job->prefix.size,
        ZSTD_dct_rawContent, ZSTD_dtlm_fast, NULL, /*cdict*/
        &state->jobParams, pledgedSrcSize);
}

static void ZSTDMT_compressionJobPublishFrameHeader(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;

    state->frameHeaderState.stage = (int*)&state->cctx->stage;
    state->frameHeaderState.noDictIDFlag =
            state->cctx->appliedParams.fParams.noDictIDFlag;
    state->frameHeaderState.checksumFlag =
            state->cctx->appliedParams.fParams.checksumFlag;
    state->frameHeaderState.contentSizeFlag =
            state->cctx->appliedParams.fParams.contentSizeFlag;
    state->frameHeaderState.format = (int)state->cctx->appliedParams.format;
    state->frameHeaderState.windowLog =
            state->cctx->appliedParams.cParams.windowLog;
    state->frameHeaderState.pledgedSrcSizePlusOne =
            state->cctx->pledgedSrcSizePlusOne;
    state->frameHeaderState.dictID = state->cctx->dictID;
    state->frameHeaderState.repCodes = state->cctx->blockState.prevCBlock == NULL
            ? NULL : state->cctx->blockState.prevCBlock->rep;
}

static ZSTDMT_chunkProcessResult ZSTDMT_compressionJobCompress(
        void* opaque, unsigned lastJob)
{
    ZSTDMT_compressionJobState* const state =
            (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;
    ZSTDMT_RustCompressionJobProgressProjection progress;
    size_t const chunkSize = 4*ZSTD_BLOCKSIZE_MAX;

    assert(lastJob == job->lastJob);
    if (sizeof(size_t) > sizeof(int)) assert(job->src.size < ((size_t)INT_MAX) * chunkSize);   /* check overflow */
    DEBUGLOG(5, "ZSTDMT_compressionJob: compress %u bytes in %zu blocks",
                (U32)job->src.size, (job->src.size + (chunkSize-1)) / chunkSize);
    assert(job->cSize == 0);
    assert(chunkSize > 0);
    assert((chunkSize & (chunkSize - 1)) == 0);  /* chunkSize must be power of 2 for mask==(chunkSize-1) to work */
    progress.callbackContext = job;
    progress.cSize = &job->cSize;
    progress.consumed = &job->consumed;
    progress.lock = ZSTDMT_compressionJobProgressLock;
    progress.signal = ZSTDMT_compressionJobProgressSignal;
    progress.unlock = ZSTDMT_compressionJobProgressUnlock;
    progress.debug = ZSTDMT_compressionJobProgressDebug;
    return ZSTDMT_rust_compressJobChunks(
        state->cctx, job->src.start, job->src.size,
        state->dstBuff.start, state->dstBuff.capacity, chunkSize, lastJob,
        &progress, ZSTDMT_rust_compressionJobProgress);
}

static void ZSTDMT_compressionJobTraceAssertNoExtDict(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;

    /* Double check that we don't have an ext-dict, because then our repcode
     * invalidation doesn't work. */
    assert(!ZSTD_window_hasExtDict(state->cctx->blockState.matchState.window));
}

static void ZSTDMT_compressionJobTraceRecord(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTD_CCtx_trace(state->cctx, 0);
}

static void ZSTDMT_compressionJobTrace(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_RustCompressionJobTraceProjection const projection = {
        state,
        state->job->firstJob,
        ZSTDMT_compressionJobTraceAssertNoExtDict,
        ZSTDMT_compressionJobTraceRecord
    };
    ZSTDMT_rust_compressionJobTrace(&projection);
}

static void ZSTDMT_compressionJobEnsureFinished(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;

    ZSTDMT_serialState_ensureFinished(job->serial, job->jobID, job->cSize);
    if (job->prefix.size > 0)
        DEBUGLOG(5, "Finished with prefix: %zx", (size_t)job->prefix.start);
    DEBUGLOG(5, "Finished with source: %zx", (size_t)job->src.start);
}

static void ZSTDMT_compressionJobReleaseSeq(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;

    ZSTDMT_releaseSeq(job->seqPool, state->rawSeqStore);
}

static void ZSTDMT_compressionJobReleaseCCtx(void* opaque)
{
    ZSTDMT_compressionJobState* const state =
        (ZSTDMT_compressionJobState*)opaque;
    ZSTDMT_jobDescription* const job = state->job;

    ZSTDMT_releaseCCtx(job->cctxPool, state->cctx);
}

static void ZSTDMT_compressionJobValidateConsumed(void* opaque, size_t srcSize)
{
    ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)opaque;

    assert(srcSize == job->src.size);
}

/* ZSTDMT_compressionJob() is a POOL_function type. Rust owns the stage
 * ordering; these callbacks retain the private job and codec operations. */
static void ZSTDMT_compressionJob(void* jobDescription)
{
    ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)jobDescription;
    ZSTDMT_compressionJobState state;
    ZSTDMT_RustCompressionJobSequenceState sequenceState;
    ZSTDMT_RustCompressionJobFinishPublicationProjection publication;
    ZSTDMT_RustCompressionJobFinishProjection finishProjection;
    ZSTDMT_RustCompressionJobProjection projection;

    ZSTD_memset(&state, 0, sizeof(state));
    state.job = job;
    state.jobParams = job->params;   /* do not modify job->params ! copy it, modify the copy */
    state.dstBuff = job->dstBuff;
    sequenceState = (ZSTDMT_RustCompressionJobSequenceState){
        &state.cctx,
        (ZSTDMT_RustRawSeqStore*)&state.rawSeqStore,
        job->serial->params.ldmParams.enableLdm
    };
    projection = (ZSTDMT_RustCompressionJobProjection){
        job->firstJob,
        job->lastJob,
        &state.frameHeaderState,
        &sequenceState
    };
    publication = (ZSTDMT_RustCompressionJobFinishPublicationProjection){
        job,
        &job->cSize,
        &job->consumed,
        job->src.size,
        ZSTDMT_compressionJobProgressLock,
        ZSTDMT_compressionJobProgressSignal,
        ZSTDMT_compressionJobProgressUnlock,
        ZSTDMT_compressionJobValidateConsumed
    };
    finishProjection = (ZSTDMT_RustCompressionJobFinishProjection){
        &state,
        job->src.size,
        ZSTDMT_compressionJobEnsureFinished,
        publication,
        ZSTDMT_compressionJobReleaseSeq,
        ZSTDMT_compressionJobReleaseCCtx
    };

    ZSTDMT_rust_compressionJob(
        &projection, &finishProjection, &state,
        ZSTDMT_compressionJobAcquireResources,
        ZSTDMT_compressionJobPrepareParameters,
        ZSTDMT_compressionJobGenerateSequences,
        ZSTDMT_compressionJobBegin,
        ZSTDMT_compressionJobReferenceSequences,
        ZSTDMT_compressionJobCompress,
        ZSTDMT_compressionJobTrace);
}


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

typedef struct {
    Range prefix;         /* read-only non-owned prefix buffer */
    Buffer buffer;
    size_t filled;
} InBuff_t;

typedef struct {
  BYTE* buffer;     /* The round input buffer. All jobs get references
                     * to pieces of the buffer. ZSTDMT_tryGetInputRange()
                     * handles handing out job input buffers, and makes
                     * sure it doesn't overlap with any pieces still in use.
                     */
  size_t capacity;  /* The capacity of buffer. */
  size_t pos;       /* The position of the current inBuff in the round
                     * buffer. Updated past the end if the inBuff once
                     * the inBuff is sent to the worker thread.
                     * pos <= capacity.
                     */
} RoundBuff_t;

#define RSYNC_LENGTH 32
/* Don't create chunks smaller than the zstd block size.
 * This stops us from regressing compression ratio too much,
 * and ensures our output fits in ZSTD_compressBound().
 *
 * If this is shrunk < ZSTD_BLOCKSIZELOG_MIN then
 * ZSTD_COMPRESSBOUND() will need to be updated.
 */
#define RSYNC_MIN_BLOCK_LOG ZSTD_BLOCKSIZELOG_MAX
#define RSYNC_MIN_BLOCK_SIZE (1<<RSYNC_MIN_BLOCK_LOG)

typedef struct {
  U64 hash;
  U64 hitMask;
  U64 primePower;
} RSyncState_t;

struct ZSTDMT_CCtx_s {
    POOL_ctx* factory;
    ZSTDMT_jobDescription* jobs;
    ZSTDMT_bufferPool* bufPool;
    ZSTDMT_CCtxPool* cctxPool;
    ZSTDMT_seqPool* seqPool;
    ZSTD_CCtx_params params;
    size_t targetSectionSize;
    size_t targetPrefixSize;
    int jobReady;        /* 1 => one job is already prepared, but pool has shortage of workers. Don't create a new job. */
    InBuff_t inBuff;
    RoundBuff_t roundBuff;
    SerialState serial;
    RSyncState_t rsync;
    unsigned jobIDMask;
    unsigned doneJobID;
    unsigned nextJobID;
    unsigned frameEnded;
    unsigned allJobsCompleted;
    unsigned long long frameContentSize;
    unsigned long long consumed;
    unsigned long long produced;
    ZSTD_customMem cMem;
    ZSTD_CDict* cdictLocal;
    const ZSTD_CDict* cdict;
    unsigned providedFactory: 1;
};

/* Project only the scalar job state needed by Rust's read-only MT
 * orchestration.  The descriptor layout and its mutex remain private here. */
static void ZSTDMT_projectJob(void* opaque, unsigned jobID,
                              ZSTDMT_RustJobProjection* projection)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_jobDescription* const job = &mtctx->jobs[jobID];
    ZSTD_pthread_mutex_lock(&job->job_mutex);
    projection->consumed = job->consumed;
    projection->cSize = job->cSize;
    projection->srcStart = job->src.start;
    projection->srcSize = job->src.size;
    projection->prefixStart = job->prefix.start;
    projection->prefixSize = job->prefix.size;
    projection->dstFlushed = job->dstFlushed;
    ZSTD_pthread_mutex_unlock(&job->job_mutex);
}

static void ZSTDMT_freeJobsTable(ZSTDMT_jobDescription* jobTable, U32 nbJobs, ZSTD_customMem cMem)
{
    ZSTDMT_RustFreeJobsTableProjection const projection = {
        jobTable,
        nbJobs,
        sizeof(*jobTable),
        cMem,
        ZSTDMT_job_table_destroy_sync
    };
    if (jobTable == NULL) return;
    ZSTDMT_rust_freeJobsTable(&projection);
}

int ZSTDMT_job_table_init_sync(void* jobTable, unsigned nbJobs, size_t jobSize)
{
    U32 jobNb;
    int initError = 0;
    BYTE* const table = (BYTE*)jobTable;
    assert(jobSize == sizeof(ZSTDMT_jobDescription));
    if (jobTable == NULL) return 1;
    for (jobNb=0; jobNb<nbJobs; jobNb++) {
        ZSTDMT_jobDescription* const job =
            (ZSTDMT_jobDescription*)(table + jobNb * jobSize);
        initError |= ZSTD_pthread_mutex_init(&job->job_mutex, NULL);
        initError |= ZSTD_pthread_cond_init(&job->job_cond, NULL);
    }
    return initError;
}

void ZSTDMT_job_table_destroy_sync(void* jobTable, unsigned nbJobs, size_t jobSize)
{
    U32 jobNb;
    BYTE* const table = (BYTE*)jobTable;
    if (jobTable == NULL) return;
    assert(jobSize == sizeof(ZSTDMT_jobDescription));
    for (jobNb=0; jobNb<nbJobs; jobNb++) {
        ZSTDMT_jobDescription* const job =
            (ZSTDMT_jobDescription*)(table + jobNb * jobSize);
        ZSTD_pthread_mutex_destroy(&job->job_mutex);
        ZSTD_pthread_cond_destroy(&job->job_cond);
    }
}

/* ZSTDMT_allocJobsTable()
 * allocate and init a job table.
 * update *nbJobsPtr to next power of 2 value, as size of table */
static ZSTDMT_jobDescription* ZSTDMT_createJobsTable(U32* nbJobsPtr, ZSTD_customMem cMem)
{
    return (ZSTDMT_jobDescription*) ZSTDMT_rust_createJobsTable(
        nbJobsPtr, sizeof(ZSTDMT_jobDescription), cMem,
        ZSTDMT_job_table_init_sync, ZSTDMT_job_table_destroy_sync);
}

static size_t ZSTDMT_expandJobsTable (ZSTDMT_CCtx* mtctx, U32 nbWorkers) {
    void* jobs = mtctx->jobs;
    U32 jobIDMask = mtctx->jobIDMask;
    size_t const error = ZSTDMT_rust_expandJobsTable(
        &jobs, &jobIDMask, nbWorkers, sizeof(ZSTDMT_jobDescription),
        mtctx->cMem, ZSTDMT_job_table_init_sync, ZSTDMT_job_table_destroy_sync);
    mtctx->jobs = (ZSTDMT_jobDescription*)jobs;
    mtctx->jobIDMask = jobIDMask;
    return error;
}


typedef struct {
    ZSTDMT_CCtx* mtctx;
    ZSTD_customMem cMem;
    ZSTD_threadPool* pool;
} ZSTDMT_rust_createCCtx_context;

static void* ZSTDMT_rust_createCCtx_allocate(void* opaque, size_t size)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    context->mtctx = (ZSTDMT_CCtx*)ZSTD_customCalloc(size, context->cMem);
    return context->mtctx;
}

static size_t ZSTDMT_rust_createCCtx_setWorkers(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    return ZSTD_CCtxParams_setParameter(
        &context->mtctx->params, ZSTD_c_nbWorkers, (int)nbWorkers);
}

static void ZSTDMT_rust_createCCtx_setInitialState(void* opaque)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    context->mtctx->cMem = context->cMem;
    context->mtctx->allJobsCompleted = 1;
}

static void* ZSTDMT_rust_createCCtx_factory(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    if (context->pool != NULL) {
        context->mtctx->factory = context->pool;
        context->mtctx->providedFactory = 1;
    } else {
        context->mtctx->factory = POOL_create_advanced(nbWorkers, 0, context->cMem);
        context->mtctx->providedFactory = 0;
    }
    return context->mtctx->factory;
}

static void* ZSTDMT_rust_createCCtx_jobs(void* opaque, unsigned* nbJobs)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    context->mtctx->jobs = ZSTDMT_createJobsTable((U32*)nbJobs, context->cMem);
    if (context->mtctx->jobs != NULL)
        context->mtctx->jobIDMask = *nbJobs - 1;
    return context->mtctx->jobs;
}

static void* ZSTDMT_rust_createCCtx_bufferPool(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    context->mtctx->bufPool = ZSTDMT_createBufferPool(
        BUF_POOL_MAX_NB_BUFFERS(nbWorkers), context->cMem);
    return context->mtctx->bufPool;
}

static void* ZSTDMT_rust_createCCtx_cctxPool(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    context->mtctx->cctxPool = ZSTDMT_createCCtxPool(nbWorkers, context->cMem);
    return context->mtctx->cctxPool;
}

static void* ZSTDMT_rust_createCCtx_seqPool(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    context->mtctx->seqPool = ZSTDMT_createSeqPool(nbWorkers, context->cMem);
    return context->mtctx->seqPool;
}

static int ZSTDMT_rust_createCCtx_initSerial(void* opaque)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    return ZSTDMT_serialState_init(&context->mtctx->serial);
}

static void ZSTDMT_rust_createCCtx_free(void* opaque)
{
    ZSTDMT_rust_createCCtx_context* const context =
        (ZSTDMT_rust_createCCtx_context*)opaque;
    if (context->mtctx != NULL) {
        ZSTDMT_freeCCtx(context->mtctx);
        context->mtctx = NULL;
    }
}

MEM_STATIC ZSTDMT_CCtx* ZSTDMT_createCCtx_advanced_internal(unsigned nbWorkers, ZSTD_customMem cMem, ZSTD_threadPool* pool)
{
    ZSTDMT_rust_createCCtx_context context = { NULL, cMem, pool };
    ZSTDMT_RustCreateCCtxProjection const projection = {
        &context,
        nbWorkers,
        ZSTDMT_NBWORKERS_MAX,
        sizeof(ZSTDMT_CCtx),
        cMem
    };
    DEBUGLOG(3, "ZSTDMT_createCCtx_advanced (nbWorkers = %u)", nbWorkers);
    return (ZSTDMT_CCtx*)ZSTDMT_rust_createCCtx(
        &projection,
        ZSTDMT_rust_createCCtx_allocate,
        ZSTDMT_rust_createCCtx_setWorkers,
        ZSTDMT_rust_createCCtx_setInitialState,
        ZSTDMT_rust_createCCtx_factory,
        ZSTDMT_rust_createCCtx_jobs,
        ZSTDMT_rust_createCCtx_bufferPool,
        ZSTDMT_rust_createCCtx_cctxPool,
        ZSTDMT_rust_createCCtx_seqPool,
        ZSTDMT_rust_createCCtx_initSerial,
        ZSTDMT_rust_createCCtx_free);
}

ZSTDMT_CCtx* ZSTDMT_createCCtx_advanced(unsigned nbWorkers, ZSTD_customMem cMem, ZSTD_threadPool* pool)
{
#ifdef ZSTD_MULTITHREAD
    return ZSTDMT_createCCtx_advanced_internal(nbWorkers, cMem, pool);
#else
    (void)nbWorkers;
    (void)cMem;
    (void)pool;
    return NULL;
#endif
}


static void ZSTDMT_releaseJobResource(void* opaque, unsigned jobID)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    /* Copy the mutex/cond out */
    ZSTD_pthread_mutex_t const mutex = mtctx->jobs[jobID].job_mutex;
    ZSTD_pthread_cond_t const cond = mtctx->jobs[jobID].job_cond;

    DEBUGLOG(4, "job%02u: release dst address %08X", jobID, (U32)(size_t)mtctx->jobs[jobID].dstBuff.start);
    ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[jobID].dstBuff);

    /* Clear the job description, but keep the mutex/cond */
    ZSTD_memset(&mtctx->jobs[jobID], 0, sizeof(mtctx->jobs[jobID]));
    mtctx->jobs[jobID].job_mutex = mutex;
    mtctx->jobs[jobID].job_cond = cond;
}

/* ZSTDMT_releaseAllJobResources() :
 * note : ensure all workers are killed first ! */
static void ZSTDMT_releaseAllJobResources(ZSTDMT_CCtx* mtctx)
{
    DEBUGLOG(3, "ZSTDMT_releaseAllJobResources");
    ZSTDMT_rust_releaseAllJobResources(
            mtctx->jobIDMask, mtctx, ZSTDMT_releaseJobResource);
    mtctx->inBuff.buffer = g_nullBuffer;
    mtctx->inBuff.filled = 0;
    mtctx->allJobsCompleted = 1;
}

static void ZSTDMT_waitForJobComplete(
        void* opaque, unsigned jobID, unsigned doneJobID)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_jobDescription* const job = &mtctx->jobs[jobID];
    (void)doneJobID;
    ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
    while (job->consumed < job->src.size) {
        DEBUGLOG(4, "waiting for jobCompleted signal from job %u", doneJobID);
        ZSTD_pthread_cond_wait(&job->job_cond, &job->job_mutex);
    }
    ZSTD_pthread_mutex_unlock(&job->job_mutex);
}

static void ZSTDMT_waitForAllJobsCompleted(ZSTDMT_CCtx* mtctx)
{
    DEBUGLOG(4, "ZSTDMT_waitForAllJobsCompleted");
    mtctx->doneJobID = ZSTDMT_rust_waitForAllJobsCompleted(
            mtctx->doneJobID, mtctx->nextJobID, mtctx->jobIDMask,
            mtctx, ZSTDMT_waitForJobComplete);
}

static void ZSTDMT_rust_freeCCtxFactory(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    POOL_free(mtctx->factory);   /* stop and free worker threads */
}

static void ZSTDMT_rust_freeCCtxReleaseJobResources(void* opaque)
{
    ZSTDMT_releaseAllJobResources((ZSTDMT_CCtx*)opaque);
}

static void ZSTDMT_rust_freeCCtxJobs(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_freeJobsTable(mtctx->jobs, mtctx->jobIDMask+1, mtctx->cMem);
}

static void ZSTDMT_rust_freeCCtxBufferPool(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_freeBufferPool(mtctx->bufPool);
}

static void ZSTDMT_rust_freeCCtxPool(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_freeCCtxPool(mtctx->cctxPool);
}

static void ZSTDMT_rust_freeCCtxSeqPool(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_freeSeqPool(mtctx->seqPool);
}

static void ZSTDMT_rust_freeCCtxSerialState(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_serialState_free(&mtctx->serial);
}

static void ZSTDMT_rust_freeCCtxCDict(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTD_freeCDict(mtctx->cdictLocal);
}

static void ZSTDMT_rust_freeCCtxRoundBuffer(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTD_customFree(mtctx->roundBuff.buffer, mtctx->cMem);
}

static void ZSTDMT_rust_freeCCtxContext(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTD_customFree(mtctx, mtctx->cMem);
}

size_t ZSTDMT_freeCCtx(ZSTDMT_CCtx* mtctx)
{
    ZSTDMT_RustFreeCCtxState const state = {
        mtctx,
        mtctx != NULL && mtctx->providedFactory,
        mtctx != NULL && mtctx->roundBuff.buffer != NULL,
        ZSTDMT_rust_freeCCtxFactory,
        ZSTDMT_rust_freeCCtxReleaseJobResources,
        ZSTDMT_rust_freeCCtxJobs,
        ZSTDMT_rust_freeCCtxBufferPool,
        ZSTDMT_rust_freeCCtxPool,
        ZSTDMT_rust_freeCCtxSeqPool,
        ZSTDMT_rust_freeCCtxSerialState,
        ZSTDMT_rust_freeCCtxCDict,
        ZSTDMT_rust_freeCCtxRoundBuffer,
        ZSTDMT_rust_freeCCtxContext
    };
    return ZSTDMT_rust_freeCCtx(mtctx == NULL ? NULL : &state);
}

size_t ZSTDMT_sizeof_CCtx(ZSTDMT_CCtx* mtctx)
{
    size_t mtctxSize;
    size_t factorySize;
    size_t bufferPoolSize;
    size_t jobsSize;
    size_t cctxPoolSize;
    size_t seqPoolSize;
    size_t cdictSize;
    size_t roundBuffSize;
    if (mtctx == NULL) return 0;   /* supports sizeof NULL */
    mtctxSize = sizeof(*mtctx);
    factorySize = POOL_sizeof(mtctx->factory);
    bufferPoolSize = ZSTDMT_sizeof_bufferPool(mtctx->bufPool);
    jobsSize = (mtctx->jobIDMask+1) * sizeof(ZSTDMT_jobDescription);
    cctxPoolSize = ZSTDMT_sizeof_CCtxPool(mtctx->cctxPool);
    seqPoolSize = ZSTDMT_sizeof_seqPool(mtctx->seqPool);
    cdictSize = ZSTD_sizeof_CDict(mtctx->cdictLocal);
    roundBuffSize = mtctx->roundBuff.capacity;
    return ZSTDMT_rust_sizeofCCtx(mtctxSize, factorySize, bufferPoolSize,
                                  jobsSize, cctxPoolSize, seqPoolSize,
                                  cdictSize, roundBuffSize);
}


static size_t ZSTDMT_rust_resizeFactory(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    return POOL_resize(mtctx->factory, nbWorkers) ? ERROR(memory_allocation) : 0;
}

static size_t ZSTDMT_rust_resizeJobs(void* opaque, unsigned nbWorkers)
{
    return ZSTDMT_expandJobsTable((ZSTDMT_CCtx*)opaque, nbWorkers);
}

static void* ZSTDMT_rust_resizeBufferPool(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    mtctx->bufPool = ZSTDMT_expandBufferPool(
            mtctx->bufPool, BUF_POOL_MAX_NB_BUFFERS(nbWorkers));
    return mtctx->bufPool;
}

static void* ZSTDMT_rust_resizeCCtxPool(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    mtctx->cctxPool = ZSTDMT_expandCCtxPool(mtctx->cctxPool, nbWorkers);
    return mtctx->cctxPool;
}

static void* ZSTDMT_rust_resizeSeqPool(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    mtctx->seqPool = ZSTDMT_expandSeqPool(mtctx->seqPool, nbWorkers);
    return mtctx->seqPool;
}

static size_t ZSTDMT_rust_resizeSetNbWorkers(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    (void)ZSTD_CCtxParams_setParameter(&mtctx->params, ZSTD_c_nbWorkers, (int)nbWorkers);
    return 0;
}

/* ZSTDMT_resize() :
 * @return : error code if fails, 0 on success */
static size_t ZSTDMT_resize(ZSTDMT_CCtx* mtctx, unsigned nbWorkers)
{
    ZSTDMT_RustResizeProjection const projection = { mtctx, nbWorkers };
    return ZSTDMT_rust_resize(
            &projection,
            ZSTDMT_rust_resizeFactory,
            ZSTDMT_rust_resizeJobs,
            ZSTDMT_rust_resizeBufferPool,
            ZSTDMT_rust_resizeCCtxPool,
            ZSTDMT_rust_resizeSeqPool,
            ZSTDMT_rust_resizeSetNbWorkers);
}


/*! ZSTDMT_updateCParams_whileCompressing() :
 *  Updates a selected set of compression parameters, remaining compatible with currently active frame.
 *  New parameters will be applied to next compression job. */
void ZSTDMT_updateCParams_whileCompressing(ZSTDMT_CCtx* mtctx, const ZSTD_CCtx_params* cctxParams)
{
    U32 const saved_wlog = mtctx->params.cParams.windowLog;   /* Do not modify windowLog while compressing */
    DEBUGLOG(5, "ZSTDMT_updateCParams_whileCompressing (level:%i)",
                cctxParams->compressionLevel);
    {   ZSTDMT_RustCParamsUpdateProjection const projection = {
            cctxParams->compressionLevel,
            cctxParams->srcSizeHint,
            ZSTD_CONTENTSIZE_UNKNOWN,
            0,
            ZSTD_cpm_noAttachDict,
            cctxParams->ldmParams.enableLdm,
            ZSTD_LDM_DEFAULT_WINDOW_LOG,
            cctxParams->cParams,
            cctxParams->useRowMatchFinder,
            ZSTD_getCParamsExclusionMask(),
            saved_wlog
        };
        ZSTDMT_RustCParamsUpdateResult const result =
                ZSTDMT_rust_updateCParamsWhileCompressing(projection);
        mtctx->params.compressionLevel = result.compressionLevel;
        mtctx->params.cParams = result.cParams;
    }
}

/* ZSTDMT_getFrameProgression():
 * tells how much data has been consumed (input) and produced (output) for current frame.
 * able to count progression inside worker threads.
 * Note : mutex will be acquired during statistics collection inside workers. */
ZSTD_frameProgression ZSTDMT_getFrameProgression(ZSTDMT_CCtx* mtctx)
{
    ZSTD_frameProgression const fps = ZSTDMT_rust_frameProgressionWithJobs(
            mtctx->consumed, mtctx->inBuff.filled, mtctx->produced,
            mtctx->nextJobID, mtctx->doneJobID, mtctx->nextJobID,
            mtctx->jobReady, mtctx->jobIDMask, mtctx,
            ZSTDMT_projectJob);
    DEBUGLOG(5, "ZSTDMT_getFrameProgression");
    return fps;
}


size_t ZSTDMT_toFlushNow(ZSTDMT_CCtx* mtctx)
{
    assert(mtctx->doneJobID <= mtctx->nextJobID);
    return ZSTDMT_rust_toFlushNow(mtctx->doneJobID, mtctx->nextJobID,
                                   mtctx->jobIDMask, mtctx,
                                   ZSTDMT_projectJob);
}


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

typedef struct {
    ZSTDMT_CCtx* mtctx;
    ZSTD_CCtx_params params;
    const void* dict;
    size_t dictSize;
    ZSTD_dictContentType_e dictContentType;
    const ZSTD_CDict* cdict;
    unsigned long long pledgedSrcSize;
} ZSTDMT_initCStreamState;

static size_t ZSTDMT_initCStreamResize(void* opaque, unsigned nbWorkers)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    return ZSTDMT_resize(state->mtctx, nbWorkers);
}

static void ZSTDMT_initCStreamWaitForAllJobs(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_waitForAllJobsCompleted(state->mtctx);
}

static void ZSTDMT_initCStreamReleaseAllJobResources(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_releaseAllJobResources(state->mtctx);
}

static void ZSTDMT_initCStreamApplyParameters(void* opaque, size_t jobSize)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->params.jobSize = jobSize;
    state->mtctx->params = state->params;
    state->mtctx->frameContentSize = state->pledgedSrcSize;
}

static void ZSTDMT_initCStreamReleaseLocalCDict(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTD_freeCDict(state->mtctx->cdictLocal);
}

static size_t ZSTDMT_initCStreamCreateCopiedCDict(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_CCtx* const mtctx = state->mtctx;
    mtctx->cdictLocal = ZSTD_createCDict_advanced(
        state->dict, state->dictSize, ZSTD_dlm_byCopy,
        state->dictContentType, state->params.cParams, mtctx->cMem);
    mtctx->cdict = mtctx->cdictLocal;
    return mtctx->cdictLocal == NULL ? ERROR(memory_allocation) : 0;
}

static void ZSTDMT_initCStreamAttachBorrowedCDict(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->cdictLocal = NULL;
    state->mtctx->cdict = state->cdict;
}

static size_t ZSTDMT_initCStreamPrepareDictionary(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_RustDictionaryProjection const projection = {
        state->dict != NULL,
        state->dictContentType == ZSTD_dct_rawContent
    };
    return ZSTDMT_rust_prepareCStreamDictionary(
            &projection, state,
            ZSTDMT_initCStreamReleaseLocalCDict,
            ZSTDMT_initCStreamCreateCopiedCDict,
            ZSTDMT_initCStreamAttachBorrowedCDict);
}

static void ZSTDMT_initCStreamSetTargetPrefixSize(void* opaque, size_t size)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->targetPrefixSize = size;
    DEBUGLOG(4, "overlapLog=%i => %u KB", state->params.overlapLog, (U32)(size >> 10));
}

static void ZSTDMT_initCStreamSetTargetSectionSize(void* opaque, size_t size)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->targetSectionSize = size;
}

static void ZSTDMT_initCStreamSetRsync(void* opaque, U64 hitMask, U64 primePower)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->rsync.hash = 0;
    state->mtctx->rsync.hitMask = hitMask;
    state->mtctx->rsync.primePower = primePower;
    DEBUGLOG(4, "rsyncLog = %u", ZSTD_highbit32((U32)(hitMask + 1)));
}

static void ZSTDMT_initCStreamSetBufferSize(void* opaque, size_t size)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    DEBUGLOG(4, "Job Size : %u KB (note : set to %u)",
             (U32)(state->mtctx->targetSectionSize >> 10),
             (U32)state->params.jobSize);
    DEBUGLOG(4, "inBuff Size : %u KB", (U32)(state->mtctx->targetSectionSize >> 10));
    ZSTDMT_setBufferSize(state->mtctx->bufPool, size);
}

static size_t ZSTDMT_initCStreamResizeRoundBuffer(void* opaque, size_t capacity)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_CCtx* const mtctx = state->mtctx;
    if (mtctx->roundBuff.capacity < capacity) {
        if (mtctx->roundBuff.buffer)
            ZSTD_customFree(mtctx->roundBuff.buffer, mtctx->cMem);
        mtctx->roundBuff.buffer = (BYTE*)ZSTD_customMalloc(capacity, mtctx->cMem);
        if (mtctx->roundBuff.buffer == NULL) {
            mtctx->roundBuff.capacity = 0;
            return ERROR(memory_allocation);
        }
        mtctx->roundBuff.capacity = capacity;
    }
    return 0;
}

static void ZSTDMT_initCStreamResetRoundBuffer(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->roundBuff.pos = 0;
}

static void ZSTDMT_initCStreamResetInputBuffer(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->inBuff.buffer = g_nullBuffer;
    state->mtctx->inBuff.filled = 0;
    state->mtctx->inBuff.prefix = kNullRange;
}

static void ZSTDMT_initCStreamResetJobIDs(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->doneJobID = 0;
    state->mtctx->nextJobID = 0;
}

static void ZSTDMT_initCStreamResetFrameFlags(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->frameEnded = 0;
    state->mtctx->allJobsCompleted = 0;
}

static void ZSTDMT_initCStreamResetProgress(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->consumed = 0;
    state->mtctx->produced = 0;
}

static void ZSTDMT_initCStreamResetStream(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_CCtx* const mtctx = state->mtctx;
    ZSTDMT_RustResetStreamState const resetState = {
        state,
        ZSTDMT_initCStreamResetRoundBuffer,
        ZSTDMT_initCStreamResetInputBuffer,
        ZSTDMT_initCStreamResetJobIDs,
        ZSTDMT_initCStreamResetFrameFlags,
        ZSTDMT_initCStreamResetProgress
    };
    DEBUGLOG(4, "roundBuff capacity : %u KB", (U32)(mtctx->roundBuff.capacity >> 10));
    ZSTDMT_rust_resetStream(&resetState);
}

static void ZSTDMT_initCStreamClearDictionary(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_CCtx* const mtctx = state->mtctx;
    ZSTD_freeCDict(mtctx->cdictLocal);
    mtctx->cdictLocal = NULL;
    mtctx->cdict = NULL;
}

static void ZSTDMT_initCStreamSetRawPrefix(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    state->mtctx->inBuff.prefix.start = (const BYTE*)state->dict;
    state->mtctx->inBuff.prefix.size = state->dictSize;
}

static size_t ZSTDMT_initCStreamCreateReferencedCDict(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_CCtx* const mtctx = state->mtctx;
    /* note : a loadPrefix becomes an internal CDict */
    mtctx->cdictLocal = ZSTD_createCDict_advanced(
        state->dict, state->dictSize, ZSTD_dlm_byRef,
        state->dictContentType, state->params.cParams, mtctx->cMem);
    mtctx->cdict = mtctx->cdictLocal;
    return mtctx->cdictLocal == NULL ? ERROR(memory_allocation) : 0;
}

static size_t ZSTDMT_initCStreamUpdateDictionary(void* opaque)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    ZSTDMT_RustDictionaryProjection const projection = {
        state->dict != NULL,
        state->dictContentType == ZSTD_dct_rawContent
    };
    return ZSTDMT_rust_updateCStreamDictionary(
            &projection, state,
            ZSTDMT_initCStreamClearDictionary,
            ZSTDMT_initCStreamAttachBorrowedCDict,
            ZSTDMT_initCStreamSetRawPrefix,
            ZSTDMT_initCStreamCreateReferencedCDict);
}

static size_t ZSTDMT_initCStreamSerialReset(void* opaque, size_t targetSectionSize)
{
    ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
    return ZSTDMT_rust_initSerialResetResult(ZSTDMT_serialState_reset(
            &state->mtctx->serial, state->mtctx->seqPool, state->params,
            targetSectionSize, state->dict, state->dictSize,
            state->dictContentType));
}

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

size_t ZSTDMT_initCStream_internal(
        ZSTDMT_CCtx* mtctx,
        const void* dict, size_t dictSize, ZSTD_dictContentType_e dictContentType,
        const ZSTD_CDict* cdict, ZSTD_CCtx_params params,
        unsigned long long pledgedSrcSize)
{
    ZSTDMT_initCStreamState state;
    ZSTDMT_RustInitCStreamProjection projection;

    DEBUGLOG(4, "ZSTDMT_initCStream_internal (pledgedSrcSize=%u, nbWorkers=%u, cctxPool=%u)",
                (U32)pledgedSrcSize, params.nbWorkers, mtctx->cctxPool->totalCCtx);

    /* params supposed partially fully validated at this point */
    assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
    assert(!((dict) && (cdict)));  /* either dict or cdict, not both */

    state = (ZSTDMT_initCStreamState){
        mtctx, params, dict, dictSize, dictContentType, cdict, pledgedSrcSize
    };
    projection = (ZSTDMT_RustInitCStreamProjection){
        (unsigned)params.nbWorkers,
        (unsigned)mtctx->params.nbWorkers,
        params.jobSize,
        ZSTDMT_JOBSIZE_MIN,
        (size_t)ZSTDMT_JOBSIZE_MAX,
        params.ldmParams.enableLdm,
        params.cParams.windowLog,
        params.cParams.chainLog,
        params.cParams.strategy,
        params.overlapLog,
        params.rsyncable,
        mtctx->roundBuff.capacity,
        mtctx->allJobsCompleted
    };

    return ZSTDMT_rust_initCStream(
        &projection, &state,
        ZSTDMT_initCStreamResize,
        ZSTDMT_initCStreamWaitForAllJobs,
        ZSTDMT_initCStreamReleaseAllJobResources,
        ZSTDMT_initCStreamApplyParameters,
        ZSTDMT_initCStreamPrepareDictionary,
        ZSTDMT_initCStreamSetTargetPrefixSize,
        ZSTDMT_initCStreamSetTargetSectionSize,
        ZSTDMT_initCStreamSetRsync,
        ZSTDMT_initCStreamSetBufferSize,
        ZSTDMT_initCStreamResizeRoundBuffer,
        ZSTDMT_initCStreamResetStream,
        ZSTDMT_initCStreamUpdateDictionary,
        ZSTDMT_initCStreamSerialReset);
}


/* ZSTDMT_writeLastEmptyBlock()
 * Write a single empty block with an end-of-frame to finish a frame.
 * Job must be created from streaming variant.
 * This function is always successful if expected conditions are fulfilled.
 */
static void ZSTDMT_writeLastEmptyBlock(ZSTDMT_jobDescription* job)
{
    ZSTDMT_RustEmptyBlockJobProjection projection;
    ZSTDMT_RustEmptyBlockResult result;

    assert(job->lastJob == 1);
    assert(job->src.size == 0);   /* last job is empty -> will be simplified into a last empty block */
    assert(job->firstJob == 0);   /* cannot be first job, as it also needs to create frame header */
    assert(job->dstBuff.start == NULL);   /* invoked from streaming variant only (otherwise, dstBuff might be user's output) */
    assert(job->consumed == 0);

    projection = (ZSTDMT_RustEmptyBlockJobProjection){
        job->lastJob,
        job->src.size,
        job->firstJob,
        job->dstBuff.start,
        job->dstBuff.capacity,
        job->consumed
    };
    result = ZSTDMT_rust_writeLastEmptyBlock(
            &projection, job->bufPool, ZSTDMT_getBufferForRust);

    job->dstBuff = (Buffer){ result.buffer.start, result.buffer.capacity };
    if (job->dstBuff.start == NULL) {
        assert(!result.clearSource);
        job->cSize = result.cSize;
        return;
    }
    assert(result.clearSource);
    assert(job->dstBuff.capacity >= ZSTD_blockHeaderSize);   /* no buffer should ever be that small */
    if (result.clearSource) job->src = kNullRange;
    job->cSize = result.cSize;
    assert(!ZSTD_isError(job->cSize));
}

static void ZSTDMT_prepareCompressionJobDescriptor(
        void* opaque, unsigned jobID,
        const ZSTDMT_RustJobInitialization* initialization)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_jobDescription* const job = &mtctx->jobs[jobID];
    BYTE const* const src = (const BYTE*)initialization->srcStart;

    DEBUGLOG(5, "ZSTDMT_createCompressionJob: preparing job %u to compress %u bytes with %u preload ",
                initialization->jobNumber, (U32)initialization->srcSize,
                (U32)initialization->prefixSize);
    assert(mtctx->inBuff.filled >= initialization->srcSize);
    job->src = (Range){ src, initialization->srcSize };
    job->prefix = (Range){
        (const BYTE*)initialization->prefixStart, initialization->prefixSize
    };
    job->consumed = 0;
    job->cSize = 0;
    job->params = mtctx->params;
    job->cdict = initialization->firstJob ? mtctx->cdict : NULL;
    job->fullFrameSize = mtctx->frameContentSize;
    job->dstBuff = g_nullBuffer;
    job->cctxPool = mtctx->cctxPool;
    job->bufPool = mtctx->bufPool;
    job->seqPool = mtctx->seqPool;
    job->serial = &mtctx->serial;
    job->jobID = initialization->jobNumber;
    job->firstJob = initialization->firstJob;
    job->lastJob = initialization->lastJob;
    job->frameChecksumNeeded = initialization->frameChecksumNeeded;
    job->dstFlushed = 0;
}

static void ZSTDMT_prepareCompressionJobInputState(
        void* opaque, unsigned jobID,
        const ZSTDMT_RustJobInitialization* initialization)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    (void)jobID;
    /* Update the round buffer position and clear the input buffer to be reset. */
    mtctx->roundBuff.pos += initialization->roundBuffPosDelta;
    mtctx->inBuff.buffer = g_nullBuffer;
    mtctx->inBuff.filled = 0;
    mtctx->inBuff.prefix = (Range){
        (const BYTE*)initialization->nextPrefixStart,
        initialization->nextPrefixSize
    };
}

static void ZSTDMT_prepareCompressionJobSetFrameEnded(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    mtctx->frameEnded = 1;
}

static void ZSTDMT_prepareCompressionJobClearChecksumFlag(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    mtctx->params.fParams.checksumFlag = 0;
}

static void ZSTDMT_prepareCompressionJob(
        void* opaque, unsigned jobID,
        const ZSTDMT_RustJobInitialization* initialization)
{
    ZSTDMT_rust_prepareCompressionJob(
            opaque, jobID, initialization,
            ZSTDMT_prepareCompressionJobDescriptor,
            ZSTDMT_prepareCompressionJobInputState,
            ZSTDMT_prepareCompressionJobSetFrameEnded,
            ZSTDMT_prepareCompressionJobClearChecksumFlag);
}

static void ZSTDMT_writeEmptyCompressionJob(void* opaque, unsigned jobID)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_writeLastEmptyBlock(&mtctx->jobs[jobID]);
}

static int ZSTDMT_tryAddCompressionJob(void* opaque, unsigned jobID)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    return POOL_tryAdd(mtctx->factory, ZSTDMT_compressionJob, &mtctx->jobs[jobID]);
}

static ZSTDMT_RustStreamCreateJobResult ZSTDMT_createCompressionJob(
        void* opaque, size_t srcSize, unsigned end)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTD_EndDirective const endOp = (ZSTD_EndDirective)end;
    ZSTDMT_RustCreateJobProjection projection;
    ZSTDMT_RustCreateJobResult result;
    ZSTDMT_RustStreamCreateJobResult streamResult;
    /* Rust fills the reusable input range in its local projection before
     * calling this C-owned job-construction callback.  Publish that count
     * before the callback prepares a job and checks the C context. */
    assert(srcSize <= mtctx->inBuff.buffer.capacity);
    mtctx->inBuff.filled = srcSize;
    projection = (ZSTDMT_RustCreateJobProjection){
        mtctx->doneJobID,
        mtctx->nextJobID,
        mtctx->jobIDMask,
        mtctx->jobReady,
        mtctx->inBuff.buffer.start,
        srcSize,
        mtctx->inBuff.filled,
        mtctx->inBuff.prefix.start,
        mtctx->inBuff.prefix.size,
        mtctx->targetPrefixSize,
        (unsigned)(endOp == ZSTD_e_end),
        (unsigned)mtctx->params.fParams.checksumFlag
    };
    result = ZSTDMT_rust_createCompressionJob(
            &projection, mtctx, ZSTDMT_prepareCompressionJob,
            ZSTDMT_writeEmptyCompressionJob, ZSTDMT_tryAddCompressionJob);
    /* Keep the private C mutation in this callback, but let Rust decide
     * whether its local inBuffFilled value may be published afterwards. */
    streamResult = (ZSTDMT_RustStreamCreateJobResult){
        result.returnCode,
        (unsigned)(mtctx->inBuff.buffer.start != NULL)
    };

    if (result.action == ZSTDMT_CREATE_JOB_TABLE_FULL) {
        DEBUGLOG(5, "ZSTDMT_createCompressionJob: will not create new job : table is full");
        assert((mtctx->nextJobID & mtctx->jobIDMask) == (mtctx->doneJobID & mtctx->jobIDMask));
        return streamResult;
    }

    mtctx->nextJobID = result.nextJobID;
    mtctx->jobReady = result.jobReady;
    if (result.action == ZSTDMT_CREATE_JOB_EMPTY) {
        DEBUGLOG(5, "ZSTDMT_createCompressionJob: creating a last empty block to end frame");
        assert(endOp == ZSTD_e_end);  /* only possible case : need to end the frame with an empty last block */
        return streamResult;
    }

    DEBUGLOG(5, "ZSTDMT_createCompressionJob: posting job %u : %u bytes  (end:%u, jobNb == %u (mod:%u))",
                result.jobNumber,
                (U32)mtctx->jobs[result.jobID].src.size,
                mtctx->jobs[result.jobID].lastJob,
                result.jobNumber,
                result.jobID);
    if (result.jobReady)
        DEBUGLOG(5, "ZSTDMT_createCompressionJob: no worker available for job %u", result.jobNumber);
    return streamResult;
}

/* The Rust flush state machine receives only this synchronized scalar view.
 * The descriptor, condition variable, serial checksum state, and buffer pool
 * remain private to C. */
static void ZSTDMT_projectFlushJob(void* opaque, unsigned jobID,
                                   unsigned blockToFlush,
                                   ZSTDMT_RustFlushJobProjection* projection)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_jobDescription* const job = &mtctx->jobs[jobID];

    ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
    if (blockToFlush && (mtctx->doneJobID < mtctx->nextJobID)) {
        assert(job->dstFlushed <= job->cSize);
        while (job->dstFlushed == job->cSize) {  /* nothing to flush */
            if (job->consumed == job->src.size) break;
            ZSTD_pthread_cond_wait(&job->job_cond, &job->job_mutex);
        }
    }
    *projection = (ZSTDMT_RustFlushJobProjection){
        job->consumed,
        job->cSize,
        job->src.size,
        job->dstBuff.start,
        job->dstBuff.capacity,
        job->dstFlushed,
        job->frameChecksumNeeded
    };
    ZSTD_pthread_mutex_unlock(&job->job_mutex);
}

static void ZSTDMT_addFrameChecksum(void* opaque, unsigned jobID,
                                    ZSTDMT_RustFlushJobProjection* projection)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_jobDescription* const job = &mtctx->jobs[jobID];
    ZSTDMT_RustFrameChecksumProjection const checksumProjection = {
        job->dstBuff.start,
        job->dstBuff.capacity,
        job->cSize,
        &mtctx->serial.xxhState
    };
    size_t const cSize = ZSTDMT_rust_writeFrameChecksum(&checksumProjection);

    assert(projection->frameChecksumNeeded);
    assert(projection->consumed == projection->srcSize);
    assert(projection->cSize == job->cSize);
    job->cSize = cSize;
    projection->cSize = cSize;
    if (!ZSTD_isError(cSize)) {
        job->frameChecksumNeeded = 0;
        projection->frameChecksumNeeded = 0;
    }
}

static void ZSTDMT_updateFlushJob(void* opaque, unsigned jobID, size_t dstFlushed)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_jobDescription* const job = &mtctx->jobs[jobID];

    assert(dstFlushed <= job->cSize);
    job->dstFlushed = dstFlushed;
}

static void ZSTDMT_completeFlushJob(void* opaque, unsigned jobID,
                                    size_t srcSize, size_t cSize)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_jobDescription* const job = &mtctx->jobs[jobID];

    assert(jobID == (mtctx->doneJobID & mtctx->jobIDMask));
    assert(job->src.size == srcSize);
    assert(job->cSize == cSize);
    assert(job->dstFlushed == cSize);
    ZSTDMT_releaseBuffer(mtctx->bufPool, job->dstBuff);
    job->dstBuff = g_nullBuffer;
    job->cSize = 0;   /* ensure this job slot is considered "not started" in future check */
    mtctx->consumed += srcSize;
    mtctx->produced += cSize;
    mtctx->doneJobID++;
}

static void ZSTDMT_flushWaitForAllJobs(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_waitForAllJobsCompleted(mtctx);
}

static void ZSTDMT_flushReleaseAllJobResources(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTDMT_releaseAllJobResources(mtctx);
}

/*! ZSTDMT_flushProduced() :
 *  flush whatever data has been produced but not yet flushed in current job.
 *  move to next job if current one is fully flushed.
 * `output` : `pos` 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, 0 if no more, 1 if unknown but > 0, or an error code */
static size_t ZSTDMT_flushProduced(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, unsigned blockToFlush, ZSTD_EndDirective end)
{
    ZSTDMT_RustFlushContextProjection const context = {
        mtctx->doneJobID,
        mtctx->nextJobID,
        mtctx->jobIDMask,
        mtctx->jobReady,
        mtctx->frameEnded,
        mtctx->inBuff.filled
    };
    ZSTDMT_RustFlushProducedResult const result = ZSTDMT_rust_flushProduced(
            &context,
            output->dst, output->size, output->pos,
            blockToFlush, (unsigned)end, mtctx,
            ZSTDMT_projectFlushJob,
            ZSTDMT_addFrameChecksum,
            ZSTDMT_updateFlushJob,
            ZSTDMT_completeFlushJob,
            ZSTDMT_flushWaitForAllJobs,
            ZSTDMT_flushReleaseAllJobResources);

    assert(output->size >= output->pos);
    output->pos = result.outputPos;
    if (result.updateAllJobsCompleted)
        mtctx->allJobsCompleted = result.allJobsCompleted;
    return result.result;
}

static ZSTDMT_RustStreamFlushResult ZSTDMT_streamFlushProduced(
        void* opaque, void* outputDst, size_t outputSize, size_t outputPos,
        unsigned blockToFlush, unsigned end)
{
    ZSTD_outBuffer output = { outputDst, outputSize, outputPos };
    size_t const result = ZSTDMT_flushProduced(
            (ZSTDMT_CCtx*)opaque, &output, blockToFlush, (ZSTD_EndDirective)end);
    return (ZSTDMT_RustStreamFlushResult){ result, output.pos };
}

/**
 * Returns the range of data used by the earliest job that is not yet complete.
 * If the data of the first job is broken up into two segments, we cover both
 * sections.
 */
static Range ZSTDMT_getInputDataInUse(ZSTDMT_CCtx* mtctx)
{
    ZSTDMT_RustInputRange const range = ZSTDMT_rust_getInputDataInUse(
            mtctx->doneJobID, mtctx->nextJobID, mtctx->jobIDMask,
            mtctx->roundBuff.capacity, mtctx->targetSectionSize,
            mtctx, ZSTDMT_projectJob);
    return (Range){ range.start, range.size };
}

int ZSTDMT_doesOverlapWindow(Buffer buffer, ZSTD_window_t window);

static void ZSTDMT_waitForLdmLock(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    ZSTD_PTHREAD_MUTEX_LOCK(&mtctx->serial.ldmWindowMutex);
}

static int ZSTDMT_waitForLdmOverlap(
        void* opaque, void* bufferStart, size_t bufferCapacity)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    Buffer const buffer = { bufferStart, bufferCapacity };
    return ZSTDMT_doesOverlapWindow(buffer, mtctx->serial.ldmWindow);
}

static void ZSTDMT_waitForLdmWait(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    DEBUGLOG(5, "Waiting for LDM to finish...");
    ZSTD_pthread_cond_wait(&mtctx->serial.ldmWindowCond,
                           &mtctx->serial.ldmWindowMutex);
}

static void ZSTDMT_waitForLdmUnlock(void* opaque)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    DEBUGLOG(6, "Done waiting for LDM to finish");
    ZSTD_pthread_mutex_unlock(&mtctx->serial.ldmWindowMutex);
}

static void ZSTDMT_waitForLdmComplete(ZSTDMT_CCtx* mtctx, Buffer buffer)
{
    int const ldmEnabled = mtctx->params.ldmParams.enableLdm == ZSTD_ps_enable;
    ZSTDMT_RustWaitForLdmState state;
    if (ldmEnabled) {
        DEBUGLOG(5, "ZSTDMT_waitForLdmComplete");
        DEBUGLOG(5, "source  [0x%zx, 0x%zx)",
                    (size_t)buffer.start,
                    (size_t)buffer.start + buffer.capacity);
    }
    state.callbackContext = mtctx;
    state.bufferStart = buffer.start;
    state.bufferCapacity = buffer.capacity;
    state.ldmEnabled = ldmEnabled;
    state.lock = ZSTDMT_waitForLdmLock;
    state.overlaps = ZSTDMT_waitForLdmOverlap;
    state.wait = ZSTDMT_waitForLdmWait;
    state.unlock = ZSTDMT_waitForLdmUnlock;
    ZSTDMT_rust_waitForLdmComplete(&state);
}

static void ZSTDMT_inputRangeWaitForLdm(
        void* opaque, void* bufferStart, size_t bufferCapacity)
{
    ZSTDMT_waitForLdmComplete((ZSTDMT_CCtx*)opaque,
                              (Buffer){ bufferStart, bufferCapacity });
}

static void ZSTDMT_inputRangeMovePrefix(
        void* opaque, void* destination, const void* source, size_t size,
        size_t roundBufferPos)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    /* ZSTD_invalidateRepCodes() doesn't work for extDict variants.
     * Simply copy the prefix to the beginning in that case. */
    ZSTD_memmove(destination, source, size);
    mtctx->inBuff.prefix.start = (const BYTE*)destination;
    mtctx->roundBuff.pos = roundBufferPos;
}

static void ZSTDMT_inputRangePublishBuffer(
        void* opaque, void* bufferStart, size_t bufferCapacity)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    Buffer const buffer = { bufferStart, bufferCapacity };

    DEBUGLOG(5, "Using prefix range [%zx, %zx)",
                (size_t)mtctx->inBuff.prefix.start,
                (size_t)mtctx->inBuff.prefix.start + mtctx->inBuff.prefix.size);
    DEBUGLOG(5, "Using source range [%zx, %zx)",
                (size_t)buffer.start,
                (size_t)buffer.start + buffer.capacity);

    mtctx->inBuff.buffer = buffer;
    mtctx->inBuff.filled = 0;
    assert(mtctx->roundBuff.pos + buffer.capacity <= mtctx->roundBuff.capacity);
}

/**
 * Attempts to set the inBuff to the next section to fill.
 * If any part of the new section is still in use we give up.
 * Returns non-zero if the buffer is filled.
 */
static int ZSTDMT_tryGetInputRange(ZSTDMT_CCtx* mtctx)
{
    Range const inUse = ZSTDMT_getInputDataInUse(mtctx);
    ZSTDMT_RustTryGetInputRangeProjection const projection = {
        mtctx->roundBuff.buffer,
        mtctx->roundBuff.capacity,
        mtctx->roundBuff.pos,
        mtctx->inBuff.prefix.start,
        mtctx->inBuff.prefix.size,
        mtctx->targetSectionSize,
        inUse.start,
        inUse.size
    };
    ZSTDMT_RustTryGetInputRangeResult const result =
        ZSTDMT_rust_tryGetInputRange(&projection);

    DEBUGLOG(5, "ZSTDMT_tryGetInputRange");
    assert(mtctx->inBuff.buffer.start == NULL);

    if (!ZSTDMT_rust_commitInputRange(
                &result,
                mtctx->roundBuff.buffer,
                mtctx->inBuff.prefix.start,
                mtctx->inBuff.prefix.size,
                mtctx,
                ZSTDMT_inputRangeWaitForLdm,
                ZSTDMT_inputRangeMovePrefix,
                ZSTDMT_inputRangePublishBuffer)) {
        DEBUGLOG(5, "Waiting for buffer...");
        return 0;
    }
    return 1;
}

/**
 * Searches through the input for a synchronization point. If one is found, we
 * will instruct the caller to flush, and return the number of bytes to load.
 * Otherwise, we will load as many bytes as possible and instruct the caller
 * to continue as normal.
 */
/* Adapter callback for the C-owned reusable input range. */
static int ZSTDMT_streamTryGetInputRange(
        void* opaque, ZSTDMT_RustStreamInputRangeProjection* projection)
{
    ZSTDMT_CCtx* const mtctx = (ZSTDMT_CCtx*)opaque;
    int const ready = ZSTDMT_tryGetInputRange(mtctx);
    *projection = (ZSTDMT_RustStreamInputRangeProjection){
        mtctx->inBuff.buffer.start,
        mtctx->inBuff.buffer.capacity,
        mtctx->inBuff.filled
    };
    return ready;
}

size_t ZSTDMT_nextInputSizeHint(const ZSTDMT_CCtx* mtctx)
{
    return ZSTDMT_rust_nextInputSizeHint(mtctx->targetSectionSize,
                                         mtctx->inBuff.filled);
}

/** ZSTDMT_compressStream_generic() :
 *  internal use only - exposed to be invoked from zstd_compress.c
 *  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)
{
    ZSTDMT_RustCompressStreamContextProjection const context = {
        mtctx->frameEnded,
        (unsigned)mtctx->jobReady,
        mtctx->inBuff.buffer.start,
        mtctx->inBuff.buffer.capacity,
        mtctx->inBuff.filled,
        mtctx->targetSectionSize,
        mtctx->params.rsyncable,
        mtctx->rsync.primePower,
        mtctx->rsync.hitMask
    };
    ZSTDMT_RustStreamInputProjection const inputProjection = {
        input->src,
        input->size,
        input->pos
    };
    ZSTDMT_RustStreamOutputProjection const outputProjection = {
        output->dst,
        output->size,
        output->pos
    };
    ZSTDMT_RustCompressStreamResult const result =
        ZSTDMT_rust_compressStreamGeneric(
            &context, &inputProjection, &outputProjection, (unsigned)endOp,
            mtctx, ZSTDMT_streamTryGetInputRange,
            ZSTDMT_createCompressionJob, ZSTDMT_streamFlushProduced);

    DEBUGLOG(5, "ZSTDMT_compressStream_generic (endOp=%u, srcSize=%u)",
                (U32)endOp, (U32)(input->size - input->pos));
    assert(output->pos <= output->size);
    assert(input->pos  <= input->size);
    /* Rust owns the decision to publish its local count.  C retains the
     * private field mutation and receives either the count or zero when the
     * job callback cleared the range. */
    mtctx->inBuff.filled = result.inBuffFilled;
    input->pos = result.inputPos;
    output->pos = result.outputPos;
    DEBUGLOG(5, "end of ZSTDMT_compressStream_generic: remainingToFlush = %u", (U32)result.result);
    return result.result;
}