text: /*
   * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
   * All rights reserved.
   *
   * This source code is licensed under both the BSD-style license (found in the
   * LICENSE file in the root directory of this source tree) and the GPLv2 (found
   * in the COPYING file in the root directory of this source tree).
   * You may select, at your option, one of the above-listed licenses.
   */
  
  /*-*************************************
  *  Dependencies
  ***************************************/
  #include <limits.h>         /* INT_MAX */
  #include <string.h>         /* memset */
  #include "cpu.h"
  #include "mem.h"
  #include "hist.h"           /* HIST_countFast_wksp */
  #define FSE_STATIC_LINKING_ONLY   /* FSE_encodeSymbol */
  #include "fse.h"
  #define HUF_STATIC_LINKING_ONLY
  #include "huf.h"
  #include "zstd_compress_internal.h"
  #include "zstd_compress_sequences.h"
  #include "zstd_compress_literals.h"
  #include "zstd_fast.h"
  #include "zstd_double_fast.h"
  #include "zstd_lazy.h"
  #include "zstd_opt.h"
  #include "zstd_ldm.h"
  
  
  /*-*************************************
  *  Helper functions
  ***************************************/
  size_t ZSTD_compressBound(size_t srcSize) {
      return ZSTD_COMPRESSBOUND(srcSize);
  }
  
  
  /*-*************************************
  *  Context memory management
  ***************************************/
  struct ZSTD_CDict_s {
      const void* dictContent;
      size_t dictContentSize;
      U32* entropyWorkspace; /* entropy workspace of HUF_WORKSPACE_SIZE bytes */
      ZSTD_cwksp workspace;
      ZSTD_matchState_t matchState;
      ZSTD_compressedBlockState_t cBlockState;
      ZSTD_customMem customMem;
      U32 dictID;
      int compressionLevel; /* 0 indicates that advanced API was used to select CDict params */
  };  /* typedef'd to ZSTD_CDict within "zstd.h" */
  
  ZSTD_CCtx* ZSTD_createCCtx(void)
  {
      return ZSTD_createCCtx_advanced(ZSTD_defaultCMem);
  }
  
  static void ZSTD_initCCtx(ZSTD_CCtx* cctx, ZSTD_customMem memManager)
  {
      assert(cctx != NULL);
      memset(cctx, 0, sizeof(*cctx));
      cctx->customMem = memManager;
      cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
      {   size_t const err = ZSTD_CCtx_reset(cctx, ZSTD_reset_parameters);
          assert(!ZSTD_isError(err));
          (void)err;
      }
  }
  
  ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem)
  {
      ZSTD_STATIC_ASSERT(zcss_init==0);
      ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN==(0ULL - 1));
      if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
      {   ZSTD_CCtx* const cctx = (ZSTD_CCtx*)ZSTD_malloc(sizeof(ZSTD_CCtx), customMem);
          if (!cctx) return NULL;
          ZSTD_initCCtx(cctx, customMem);
          return cctx;
      }
  }
  
  ZSTD_CCtx* ZSTD_initStaticCCtx(void *workspace, size_t workspaceSize)
  {
      ZSTD_cwksp ws;
      ZSTD_CCtx* cctx;
      if (workspaceSize <= sizeof(ZSTD_CCtx)) return NULL;  /* minimum size */
      if ((size_t)workspace & 7) return NULL;  /* must be 8-aligned */
      ZSTD_cwksp_init(&ws, workspace, workspaceSize);
  
      cctx = (ZSTD_CCtx*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CCtx));
      if (cctx == NULL) {
          return NULL;
      }
      memset(cctx, 0, sizeof(ZSTD_CCtx));
      ZSTD_cwksp_move(&cctx->workspace, &ws);
      cctx->staticSize = workspaceSize;
  
      /* statically sized space. entropyWorkspace never moves (but prev/next block swap places) */
      if (!ZSTD_cwksp_check_available(&cctx->workspace, HUF_WORKSPACE_SIZE + 2 * sizeof(ZSTD_compressedBlockState_t))) return NULL;
      cctx->blockState.prevCBlock = (ZSTD_compressedBlockState_t*)ZSTD_cwksp_reserve_object(&cctx->workspace, sizeof(ZSTD_compressedBlockState_t));
      cctx->blockState.nextCBlock = (ZSTD_compressedBlockState_t*)ZSTD_cwksp_reserve_object(&cctx->workspace, sizeof(ZSTD_compressedBlockState_t));
      cctx->entropyWorkspace = (U32*)ZSTD_cwksp_reserve_object(
          &cctx->workspace, HUF_WORKSPACE_SIZE);
      cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
      return cctx;
  }
  
  /**
   * Clears and frees all of the dictionaries in the CCtx.
   */
  static void ZSTD_clearAllDicts(ZSTD_CCtx* cctx)
  {
      ZSTD_free(cctx->localDict.dictBuffer, cctx->customMem);
      ZSTD_freeCDict(cctx->localDict.cdict);
      memset(&cctx->localDict, 0, sizeof(cctx->localDict));
      memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));
      cctx->cdict = NULL;
  }
  
  static size_t ZSTD_sizeof_localDict(ZSTD_localDict dict)
  {
      size_t const bufferSize = dict.dictBuffer != NULL ? dict.dictSize : 0;
      size_t const cdictSize = ZSTD_sizeof_CDict(dict.cdict);
      return bufferSize + cdictSize;
  }
  
  static void ZSTD_freeCCtxContent(ZSTD_CCtx* cctx)
  {
      assert(cctx != NULL);
      assert(cctx->staticSize == 0);
      ZSTD_clearAllDicts(cctx);
  #ifdef ZSTD_MULTITHREAD
      ZSTDMT_freeCCtx(cctx->mtctx); cctx->mtctx = NULL;
  #endif
      ZSTD_cwksp_free(&cctx->workspace, cctx->customMem);
  }
  
  size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
  {
      if (cctx==NULL) return 0;   /* support free on NULL */
      RETURN_ERROR_IF(cctx->staticSize, memory_allocation,
                      "not compatible with static CCtx");
      {
          int cctxInWorkspace = ZSTD_cwksp_owns_buffer(&cctx->workspace, cctx);
          ZSTD_freeCCtxContent(cctx);
          if (!cctxInWorkspace) {
              ZSTD_free(cctx, cctx->customMem);
          }
      }
      return 0;
  }
  
  
  static size_t ZSTD_sizeof_mtctx(const ZSTD_CCtx* cctx)
  {
  #ifdef ZSTD_MULTITHREAD
      return ZSTDMT_sizeof_CCtx(cctx->mtctx);
  #else
      (void)cctx;
      return 0;
  #endif
  }
  
  
  size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx)
  {
      if (cctx==NULL) return 0;   /* support sizeof on NULL */
      /* cctx may be in the workspace */
      return (cctx->workspace.workspace == cctx ? 0 : sizeof(*cctx))
             + ZSTD_cwksp_sizeof(&cctx->workspace)
             + ZSTD_sizeof_localDict(cctx->localDict)
             + ZSTD_sizeof_mtctx(cctx);
  }
  
  size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs)
  {
      return ZSTD_sizeof_CCtx(zcs);  /* same object */
  }
  
  /* private API call, for dictBuilder only */
  const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx) { return &(ctx->seqStore); }
  
  static ZSTD_CCtx_params ZSTD_makeCCtxParamsFromCParams(
          ZSTD_compressionParameters cParams)
  {
      ZSTD_CCtx_params cctxParams;
      memset(&cctxParams, 0, sizeof(cctxParams));
      cctxParams.cParams = cParams;
      cctxParams.compressionLevel = ZSTD_CLEVEL_DEFAULT;  /* should not matter, as all cParams are presumed properly defined */
      assert(!ZSTD_checkCParams(cParams));
      cctxParams.fParams.contentSizeFlag = 1;
      return cctxParams;
  }
  
  static ZSTD_CCtx_params* ZSTD_createCCtxParams_advanced(
          ZSTD_customMem customMem)
  {
      ZSTD_CCtx_params* params;
      if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
      params = (ZSTD_CCtx_params*)ZSTD_calloc(
              sizeof(ZSTD_CCtx_params), customMem);
      if (!params) { return NULL; }
      params->customMem = customMem;
      params->compressionLevel = ZSTD_CLEVEL_DEFAULT;
      params->fParams.contentSizeFlag = 1;
      return params;
  }
  
  ZSTD_CCtx_params* ZSTD_createCCtxParams(void)
  {
      return ZSTD_createCCtxParams_advanced(ZSTD_defaultCMem);
  }
  
  size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params)
  {
      if (params == NULL) { return 0; }
      ZSTD_free(params, params->customMem);
      return 0;
  }
  
  size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params)
  {
      return ZSTD_CCtxParams_init(params, ZSTD_CLEVEL_DEFAULT);
  }
  
  size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel) {
      RETURN_ERROR_IF(!cctxParams, GENERIC);
      memset(cctxParams, 0, sizeof(*cctxParams));
      cctxParams->compressionLevel = compressionLevel;
      cctxParams->fParams.contentSizeFlag = 1;
      return 0;
  }
  
  size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params)
  {
      RETURN_ERROR_IF(!cctxParams, GENERIC);
      FORWARD_IF_ERROR( ZSTD_checkCParams(params.cParams) );
      memset(cctxParams, 0, sizeof(*cctxParams));
      assert(!ZSTD_checkCParams(params.cParams));
      cctxParams->cParams = params.cParams;
      cctxParams->fParams = params.fParams;
      cctxParams->compressionLevel = ZSTD_CLEVEL_DEFAULT;   /* should not matter, as all cParams are presumed properly defined */
      return 0;
  }
  
  /* ZSTD_assignParamsToCCtxParams() :
   * params is presumed valid at this stage */
  static ZSTD_CCtx_params ZSTD_assignParamsToCCtxParams(
          const ZSTD_CCtx_params* cctxParams, ZSTD_parameters params)
  {
      ZSTD_CCtx_params ret = *cctxParams;
      assert(!ZSTD_checkCParams(params.cParams));
      ret.cParams = params.cParams;
      ret.fParams = params.fParams;
      ret.compressionLevel = ZSTD_CLEVEL_DEFAULT;   /* should not matter, as all cParams are presumed properly defined */
      return ret;
  }
  
  ZSTD_bounds ZSTD_cParam_getBounds(ZSTD_cParameter param)
  {
      ZSTD_bounds bounds = { 0, 0, 0 };
  
      switch(param)
      {
      case ZSTD_c_compressionLevel:
          bounds.lowerBound = ZSTD_minCLevel();
          bounds.upperBound = ZSTD_maxCLevel();
          return bounds;
  
      case ZSTD_c_windowLog:
          bounds.lowerBound = ZSTD_WINDOWLOG_MIN;
          bounds.upperBound = ZSTD_WINDOWLOG_MAX;
          return bounds;
  
      case ZSTD_c_hashLog:
          bounds.lowerBound = ZSTD_HASHLOG_MIN;
          bounds.upperBound = ZSTD_HASHLOG_MAX;
          return bounds;
  
      case ZSTD_c_chainLog:
          bounds.lowerBound = ZSTD_CHAINLOG_MIN;
          bounds.upperBound = ZSTD_CHAINLOG_MAX;
          return bounds;
  
      case ZSTD_c_searchLog:
          bounds.lowerBound = ZSTD_SEARCHLOG_MIN;
          bounds.upperBound = ZSTD_SEARCHLOG_MAX;
          return bounds;
  
      case ZSTD_c_minMatch:
          bounds.lowerBound = ZSTD_MINMATCH_MIN;
          bounds.upperBound = ZSTD_MINMATCH_MAX;
          return bounds;
  
      case ZSTD_c_targetLength:
          bounds.lowerBound = ZSTD_TARGETLENGTH_MIN;
          bounds.upperBound = ZSTD_TARGETLENGTH_MAX;
          return bounds;
  
      case ZSTD_c_strategy:
          bounds.lowerBound = ZSTD_STRATEGY_MIN;
          bounds.upperBound = ZSTD_STRATEGY_MAX;
          return bounds;
  
      case ZSTD_c_contentSizeFlag:
          bounds.lowerBound = 0;
          bounds.upperBound = 1;
          return bounds;
  
      case ZSTD_c_checksumFlag:
          bounds.lowerBound = 0;
          bounds.upperBound = 1;
          return bounds;
  
      case ZSTD_c_dictIDFlag:
          bounds.lowerBound = 0;
          bounds.upperBound = 1;
          return bounds;
  
      case ZSTD_c_nbWorkers:
          bounds.lowerBound = 0;
  #ifdef ZSTD_MULTITHREAD
          bounds.upperBound = ZSTDMT_NBWORKERS_MAX;
  #else
          bounds.upperBound = 0;
  #endif
          return bounds;
  
      case ZSTD_c_jobSize:
          bounds.lowerBound = 0;
  #ifdef ZSTD_MULTITHREAD
          bounds.upperBound = ZSTDMT_JOBSIZE_MAX;
  #else
          bounds.upperBound = 0;
  #endif
          return bounds;
  
      case ZSTD_c_overlapLog:
          bounds.lowerBound = ZSTD_OVERLAPLOG_MIN;
          bounds.upperBound = ZSTD_OVERLAPLOG_MAX;
          return bounds;
  
      case ZSTD_c_enableLongDistanceMatching:
          bounds.lowerBound = 0;
          bounds.upperBound = 1;
          return bounds;
  
      case ZSTD_c_ldmHashLog:
          bounds.lowerBound = ZSTD_LDM_HASHLOG_MIN;
          bounds.upperBound = ZSTD_LDM_HASHLOG_MAX;
          return bounds;
  
      case ZSTD_c_ldmMinMatch:
          bounds.lowerBound = ZSTD_LDM_MINMATCH_MIN;
          bounds.upperBound = ZSTD_LDM_MINMATCH_MAX;
          return bounds;
  
      case ZSTD_c_ldmBucketSizeLog:
          bounds.lowerBound = ZSTD_LDM_BUCKETSIZELOG_MIN;
          bounds.upperBound = ZSTD_LDM_BUCKETSIZELOG_MAX;
          return bounds;
  
      case ZSTD_c_ldmHashRateLog:
          bounds.lowerBound = ZSTD_LDM_HASHRATELOG_MIN;
          bounds.upperBound = ZSTD_LDM_HASHRATELOG_MAX;
          return bounds;
  
      /* experimental parameters */
      case ZSTD_c_rsyncable:
          bounds.lowerBound = 0;
          bounds.upperBound = 1;
          return bounds;
  
      case ZSTD_c_forceMaxWindow :
          bounds.lowerBound = 0;
          bounds.upperBound = 1;
          return bounds;
  
      case ZSTD_c_format:
          ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
          bounds.lowerBound = ZSTD_f_zstd1;
          bounds.upperBound = ZSTD_f_zstd1_magicless;   /* note : how to ensure at compile time that this is the highest value enum ? */
          return bounds;
  
      case ZSTD_c_forceAttachDict:
          ZSTD_STATIC_ASSERT(ZSTD_dictDefaultAttach < ZSTD_dictForceCopy);
          bounds.lowerBound = ZSTD_dictDefaultAttach;
          bounds.upperBound = ZSTD_dictForceLoad;       /* note : how to ensure at compile time that this is the highest value enum ? */
          return bounds;
  
      case ZSTD_c_literalCompressionMode:
          ZSTD_STATIC_ASSERT(ZSTD_lcm_auto < ZSTD_lcm_huffman && ZSTD_lcm_huffman < ZSTD_lcm_uncompressed);
          bounds.lowerBound = ZSTD_lcm_auto;
          bounds.upperBound = ZSTD_lcm_uncompressed;
          return bounds;
  
      case ZSTD_c_targetCBlockSize:
          bounds.lowerBound = ZSTD_TARGETCBLOCKSIZE_MIN;
          bounds.upperBound = ZSTD_TARGETCBLOCKSIZE_MAX;
          return bounds;
  
      case ZSTD_c_srcSizeHint:
          bounds.lowerBound = ZSTD_SRCSIZEHINT_MIN;
          bounds.upperBound = ZSTD_SRCSIZEHINT_MAX;
          return bounds;
  
      default:
          {   ZSTD_bounds const boundError = { ERROR(parameter_unsupported), 0, 0 };
              return boundError;
          }
      }
  }
  
  /* ZSTD_cParam_clampBounds:
   * Clamps the value into the bounded range.
   */
  static size_t ZSTD_cParam_clampBounds(ZSTD_cParameter cParam, int* value)
  {
      ZSTD_bounds const bounds = ZSTD_cParam_getBounds(cParam);
      if (ZSTD_isError(bounds.error)) return bounds.error;
      if (*value < bounds.lowerBound) *value = bounds.lowerBound;
      if (*value > bounds.upperBound) *value = bounds.upperBound;
      return 0;
  }
  
  #define BOUNDCHECK(cParam, val) { \
      RETURN_ERROR_IF(!ZSTD_cParam_withinBounds(cParam,val), \
                      parameter_outOfBound); \
  }
  
  
  static int ZSTD_isUpdateAuthorized(ZSTD_cParameter param)
  {
      switch(param)
      {
      case ZSTD_c_compressionLevel:
      case ZSTD_c_hashLog:
      case ZSTD_c_chainLog:
      case ZSTD_c_searchLog:
      case ZSTD_c_minMatch:
      case ZSTD_c_targetLength:
      case ZSTD_c_strategy:
          return 1;
  
      case ZSTD_c_format:
      case ZSTD_c_windowLog:
      case ZSTD_c_contentSizeFlag:
      case ZSTD_c_checksumFlag:
      case ZSTD_c_dictIDFlag:
      case ZSTD_c_forceMaxWindow :
      case ZSTD_c_nbWorkers:
      case ZSTD_c_jobSize:
      case ZSTD_c_overlapLog:
      case ZSTD_c_rsyncable:
      case ZSTD_c_enableLongDistanceMatching:
      case ZSTD_c_ldmHashLog:
      case ZSTD_c_ldmMinMatch:
      case ZSTD_c_ldmBucketSizeLog:
      case ZSTD_c_ldmHashRateLog:
      case ZSTD_c_forceAttachDict:
      case ZSTD_c_literalCompressionMode:
      case ZSTD_c_targetCBlockSize:
      case ZSTD_c_srcSizeHint:
      default:
          return 0;
      }
  }
  
  size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int value)
  {
      DEBUGLOG(4, "ZSTD_CCtx_setParameter (%i, %i)", (int)param, value);
      if (cctx->streamStage != zcss_init) {
          if (ZSTD_isUpdateAuthorized(param)) {
              cctx->cParamsChanged = 1;
          } else {
              RETURN_ERROR(stage_wrong);
      }   }
  
      switch(param)
      {
      case ZSTD_c_nbWorkers:
          RETURN_ERROR_IF((value!=0) && cctx->staticSize, parameter_unsupported,
                          "MT not compatible with static alloc");
          break;
  
      case ZSTD_c_compressionLevel:
      case ZSTD_c_windowLog:
      case ZSTD_c_hashLog:
      case ZSTD_c_chainLog:
      case ZSTD_c_searchLog:
      case ZSTD_c_minMatch:
      case ZSTD_c_targetLength:
      case ZSTD_c_strategy:
      case ZSTD_c_ldmHashRateLog:
      case ZSTD_c_format:
      case ZSTD_c_contentSizeFlag:
      case ZSTD_c_checksumFlag:
      case ZSTD_c_dictIDFlag:
      case ZSTD_c_forceMaxWindow:
      case ZSTD_c_forceAttachDict:
      case ZSTD_c_literalCompressionMode:
      case ZSTD_c_jobSize:
      case ZSTD_c_overlapLog:
      case ZSTD_c_rsyncable:
      case ZSTD_c_enableLongDistanceMatching:
      case ZSTD_c_ldmHashLog:
      case ZSTD_c_ldmMinMatch:
      case ZSTD_c_ldmBucketSizeLog:
      case ZSTD_c_targetCBlockSize:
      case ZSTD_c_srcSizeHint:
          break;
  
      default: RETURN_ERROR(parameter_unsupported);
      }
      return ZSTD_CCtxParams_setParameter(&cctx->requestedParams, param, value);
  }
  
  size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* CCtxParams,
                                      ZSTD_cParameter param, int value)
  {
      DEBUGLOG(4, "ZSTD_CCtxParams_setParameter (%i, %i)", (int)param, value);
      switch(param)
      {
      case ZSTD_c_format :
          BOUNDCHECK(ZSTD_c_format, value);
          CCtxParams->format = (ZSTD_format_e)value;
          return (size_t)CCtxParams->format;
  
      case ZSTD_c_compressionLevel : {
          FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(param, &value));
          if (value) {  /* 0 : does not change current level */
              CCtxParams->compressionLevel = value;
          }
          if (CCtxParams->compressionLevel >= 0) return (size_t)CCtxParams->compressionLevel;
          return 0;  /* return type (size_t) cannot represent negative values */
      }
  
      case ZSTD_c_windowLog :
          if (value!=0)   /* 0 => use default */
              BOUNDCHECK(ZSTD_c_windowLog, value);
          CCtxParams->cParams.windowLog = (U32)value;
          return CCtxParams->cParams.windowLog;
  
      case ZSTD_c_hashLog :
          if (value!=0)   /* 0 => use default */
              BOUNDCHECK(ZSTD_c_hashLog, value);
          CCtxParams->cParams.hashLog = (U32)value;
          return CCtxParams->cParams.hashLog;
  
      case ZSTD_c_chainLog :
          if (value!=0)   /* 0 => use default */
              BOUNDCHECK(ZSTD_c_chainLog, value);
          CCtxParams->cParams.chainLog = (U32)value;
          return CCtxParams->cParams.chainLog;
  
      case ZSTD_c_searchLog :
          if (value!=0)   /* 0 => use default */
              BOUNDCHECK(ZSTD_c_searchLog, value);
          CCtxParams->cParams.searchLog = (U32)value;
          return (size_t)value;
  
      case ZSTD_c_minMatch :
          if (value!=0)   /* 0 => use default */
              BOUNDCHECK(ZSTD_c_minMatch, value);
          CCtxParams->cParams.minMatch = value;
          return CCtxParams->cParams.minMatch;
  
      case ZSTD_c_targetLength :
          BOUNDCHECK(ZSTD_c_targetLength, value);
          CCtxParams->cParams.targetLength = value;
          return CCtxParams->cParams.targetLength;
  
      case ZSTD_c_strategy :
          if (value!=0)   /* 0 => use default */
              BOUNDCHECK(ZSTD_c_strategy, value);
          CCtxParams->cParams.strategy = (ZSTD_strategy)value;
          return (size_t)CCtxParams->cParams.strategy;
  
      case ZSTD_c_contentSizeFlag :
          /* Content size written in frame header _when known_ (default:1) */
          DEBUGLOG(4, "set content size flag = %u", (value!=0));
          CCtxParams->fParams.contentSizeFlag = value != 0;
          return CCtxParams->fParams.contentSizeFlag;
  
      case ZSTD_c_checksumFlag :
          /* A 32-bits content checksum will be calculated and written at end of frame (default:0) */
          CCtxParams->fParams.checksumFlag = value != 0;
          return CCtxParams->fParams.checksumFlag;
  
      case ZSTD_c_dictIDFlag : /* When applicable, dictionary's dictID is provided in frame header (default:1) */
          DEBUGLOG(4, "set dictIDFlag = %u", (value!=0));
          CCtxParams->fParams.noDictIDFlag = !value;
          return !CCtxParams->fParams.noDictIDFlag;
  
      case ZSTD_c_forceMaxWindow :
          CCtxParams->forceWindow = (value != 0);
          return CCtxParams->forceWindow;
  
      case ZSTD_c_forceAttachDict : {
          const ZSTD_dictAttachPref_e pref = (ZSTD_dictAttachPref_e)value;
          BOUNDCHECK(ZSTD_c_forceAttachDict, pref);
          CCtxParams->attachDictPref = pref;
          return CCtxParams->attachDictPref;
      }
  
      case ZSTD_c_literalCompressionMode : {
          const ZSTD_literalCompressionMode_e lcm = (ZSTD_literalCompressionMode_e)value;
          BOUNDCHECK(ZSTD_c_literalCompressionMode, lcm);
          CCtxParams->literalCompressionMode = lcm;
          return CCtxParams->literalCompressionMode;
      }
  
      case ZSTD_c_nbWorkers :
  #ifndef ZSTD_MULTITHREAD
          RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
          return 0;
  #else
          FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(param, &value));
          CCtxParams->nbWorkers = value;
          return CCtxParams->nbWorkers;
  #endif
  
      case ZSTD_c_jobSize :
  #ifndef ZSTD_MULTITHREAD
          RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
          return 0;
  #else
          /* Adjust to the minimum non-default value. */
          if (value != 0 && value < ZSTDMT_JOBSIZE_MIN)
              value = ZSTDMT_JOBSIZE_MIN;
          FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(param, &value));
          assert(value >= 0);
          CCtxParams->jobSize = value;
          return CCtxParams->jobSize;
  #endif
  
      case ZSTD_c_overlapLog :
  #ifndef ZSTD_MULTITHREAD
          RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
          return 0;
  #else
          FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(ZSTD_c_overlapLog, &value));
          CCtxParams->overlapLog = value;
          return CCtxParams->overlapLog;
  #endif
  
      case ZSTD_c_rsyncable :
  #ifndef ZSTD_MULTITHREAD
          RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
          return 0;
  #else
          FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(ZSTD_c_overlapLog, &value));
          CCtxParams->rsyncable = value;
          return CCtxParams->rsyncable;
  #endif
  
      case ZSTD_c_enableLongDistanceMatching :
          CCtxParams->ldmParams.enableLdm = (value!=0);
          return CCtxParams->ldmParams.enableLdm;
  
      case ZSTD_c_ldmHashLog :
          if (value!=0)   /* 0 ==> auto */
              BOUNDCHECK(ZSTD_c_ldmHashLog, value);
          CCtxParams->ldmParams.hashLog = value;
          return CCtxParams->ldmParams.hashLog;
  
      case ZSTD_c_ldmMinMatch :
          if (value!=0)   /* 0 ==> default */
              BOUNDCHECK(ZSTD_c_ldmMinMatch, value);
          CCtxParams->ldmParams.minMatchLength = value;
          return CCtxParams->ldmParams.minMatchLength;
  
      case ZSTD_c_ldmBucketSizeLog :
          if (value!=0)   /* 0 ==> default */
              BOUNDCHECK(ZSTD_c_ldmBucketSizeLog, value);
          CCtxParams->ldmParams.bucketSizeLog = value;
          return CCtxParams->ldmParams.bucketSizeLog;
  
      case ZSTD_c_ldmHashRateLog :
          RETURN_ERROR_IF(value > ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN,
                          parameter_outOfBound);
          CCtxParams->ldmParams.hashRateLog = value;
          return CCtxParams->ldmParams.hashRateLog;
  
      case ZSTD_c_targetCBlockSize :
          if (value!=0)   /* 0 ==> default */
              BOUNDCHECK(ZSTD_c_targetCBlockSize, value);
          CCtxParams->targetCBlockSize = value;
          return CCtxParams->targetCBlockSize;
  
      case ZSTD_c_srcSizeHint :
          if (value!=0)    /* 0 ==> default */
              BOUNDCHECK(ZSTD_c_srcSizeHint, value);
          CCtxParams->srcSizeHint = value;
          return CCtxParams->srcSizeHint;
  
      default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
      }
  }
  
  size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int* value)
  {
      return ZSTD_CCtxParams_getParameter(&cctx->requestedParams, param, value);
  }
  
  size_t ZSTD_CCtxParams_getParameter(
          ZSTD_CCtx_params* CCtxParams, ZSTD_cParameter param, int* value)
  {
      switch(param)
      {
      case ZSTD_c_format :
          *value = CCtxParams->format;
          break;
      case ZSTD_c_compressionLevel :
          *value = CCtxParams->compressionLevel;
          break;
      case ZSTD_c_windowLog :
          *value = (int)CCtxParams->cParams.windowLog;
          break;
      case ZSTD_c_hashLog :
          *value = (int)CCtxParams->cParams.hashLog;
          break;
      case ZSTD_c_chainLog :
          *value = (int)CCtxParams->cParams.chainLog;
          break;
      case ZSTD_c_searchLog :
          *value = CCtxParams->cParams.searchLog;
          break;
      case ZSTD_c_minMatch :
          *value = CCtxParams->cParams.minMatch;
          break;
      case ZSTD_c_targetLength :
          *value = CCtxParams->cParams.targetLength;
          break;
      case ZSTD_c_strategy :
          *value = (unsigned)CCtxParams->cParams.strategy;
          break;
      case ZSTD_c_contentSizeFlag :
          *value = CCtxParams->fParams.contentSizeFlag;
          break;
      case ZSTD_c_checksumFlag :
          *value = CCtxParams->fParams.checksumFlag;
          break;
      case ZSTD_c_dictIDFlag :
          *value = !CCtxParams->fParams.noDictIDFlag;
          break;
      case ZSTD_c_forceMaxWindow :
          *value = CCtxParams->forceWindow;
          break;
      case ZSTD_c_forceAttachDict :
          *value = CCtxParams->attachDictPref;
          break;
      case ZSTD_c_literalCompressionMode :
          *value = CCtxParams->literalCompressionMode;
          break;
      case ZSTD_c_nbWorkers :
  #ifndef ZSTD_MULTITHREAD
          assert(CCtxParams->nbWorkers == 0);
  #endif
          *value = CCtxParams->nbWorkers;
          break;
      case ZSTD_c_jobSize :
  #ifndef ZSTD_MULTITHREAD
          RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
  #else
          assert(CCtxParams->jobSize <= INT_MAX);
          *value = (int)CCtxParams->jobSize;
          break;
  #endif
      case ZSTD_c_overlapLog :
  #ifndef ZSTD_MULTITHREAD
          RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
  #else
          *value = CCtxParams->overlapLog;
          break;
  #endif
      case ZSTD_c_rsyncable :
  #ifndef ZSTD_MULTITHREAD
          RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
  #else
          *value = CCtxParams->rsyncable;
          break;
  #endif
      case ZSTD_c_enableLongDistanceMatching :
          *value = CCtxParams->ldmParams.enableLdm;
          break;
      case ZSTD_c_ldmHashLog :
          *value = CCtxParams->ldmParams.hashLog;
          break;
      case ZSTD_c_ldmMinMatch :
          *value = CCtxParams->ldmParams.minMatchLength;
          break;
      case ZSTD_c_ldmBucketSizeLog :
          *value = CCtxParams->ldmParams.bucketSizeLog;
          break;
      case ZSTD_c_ldmHashRateLog :
          *value = CCtxParams->ldmParams.hashRateLog;
          break;
      case ZSTD_c_targetCBlockSize :
          *value = (int)CCtxParams->targetCBlockSize;
          break;
      case ZSTD_c_srcSizeHint :
          *value = (int)CCtxParams->srcSizeHint;
          break;
      default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
      }
      return 0;
  }
  
  /** ZSTD_CCtx_setParametersUsingCCtxParams() :
   *  just applies `params` into `cctx`
   *  no action is performed, parameters are merely stored.
   *  If ZSTDMT is enabled, parameters are pushed to cctx->mtctx.
   *    This is possible even if a compression is ongoing.
   *    In which case, new parameters will be applied on the fly, starting with next compression job.
   */
  size_t ZSTD_CCtx_setParametersUsingCCtxParams(
          ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params)
  {
      DEBUGLOG(4, "ZSTD_CCtx_setParametersUsingCCtxParams");
      RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
      RETURN_ERROR_IF(cctx->cdict, stage_wrong);
  
      cctx->requestedParams = *params;
      return 0;
  }
  
  ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize)
  {
      DEBUGLOG(4, "ZSTD_CCtx_setPledgedSrcSize to %u bytes", (U32)pledgedSrcSize);
      RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
      cctx->pledgedSrcSizePlusOne = pledgedSrcSize+1;
      return 0;
  }
  
  /**
   * Initializes the local dict using the requested parameters.
   * NOTE: This does not use the pledged src size, because it may be used for more
   * than one compression.
   */
  static size_t ZSTD_initLocalDict(ZSTD_CCtx* cctx)
  {
      ZSTD_localDict* const dl = &cctx->localDict;
      ZSTD_compressionParameters const cParams = ZSTD_getCParamsFromCCtxParams(
              &cctx->requestedParams, 0, dl->dictSize);
      if (dl->dict == NULL) {
          /* No local dictionary. */
          assert(dl->dictBuffer == NULL);
          assert(dl->cdict == NULL);
          assert(dl->dictSize == 0);
          return 0;
      }
      if (dl->cdict != NULL) {
          assert(cctx->cdict == dl->cdict);
          /* Local dictionary already initialized. */
          return 0;
      }
      assert(dl->dictSize > 0);
      assert(cctx->cdict == NULL);
      assert(cctx->prefixDict.dict == NULL);
  
      dl->cdict = ZSTD_createCDict_advanced(
              dl->dict,
              dl->dictSize,
              ZSTD_dlm_byRef,
              dl->dictContentType,
              cParams,
              cctx->customMem);
      RETURN_ERROR_IF(!dl->cdict, memory_allocation);
      cctx->cdict = dl->cdict;
      return 0;
  }
  
  size_t ZSTD_CCtx_loadDictionary_advanced(
          ZSTD_CCtx* cctx, const void* dict, size_t dictSize,
          ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType)
  {
      RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
      RETURN_ERROR_IF(cctx->staticSize, memory_allocation,
                      "no malloc for static CCtx");
      DEBUGLOG(4, "ZSTD_CCtx_loadDictionary_advanced (size: %u)", (U32)dictSize);
      ZSTD_clearAllDicts(cctx);  /* in case one already exists */
      if (dict == NULL || dictSize == 0)  /* no dictionary mode */
          return 0;
      if (dictLoadMethod == ZSTD_dlm_byRef) {
          cctx->localDict.dict = dict;
      } else {
          void* dictBuffer = ZSTD_malloc(dictSize, cctx->customMem);
          RETURN_ERROR_IF(!dictBuffer, memory_allocation);
          memcpy(dictBuffer, dict, dictSize);
          cctx->localDict.dictBuffer = dictBuffer;
          cctx->localDict.dict = dictBuffer;
      }
      cctx->localDict.dictSize = dictSize;
      cctx->localDict.dictContentType = dictContentType;
      return 0;
  }
  
  ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary_byReference(
        ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
  {
      return ZSTD_CCtx_loadDictionary_advanced(
              cctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
  }
  
  ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
  {
      return ZSTD_CCtx_loadDictionary_advanced(
              cctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
  }
  
  
  size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
  {
      RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
      /* Free the existing local cdict (if any) to save memory. */
      ZSTD_clearAllDicts(cctx);
      cctx->cdict = cdict;
      return 0;
  }
  
  size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize)
  {
      return ZSTD_CCtx_refPrefix_advanced(cctx, prefix, prefixSize, ZSTD_dct_rawContent);
  }
  
  size_t ZSTD_CCtx_refPrefix_advanced(
          ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
  {
      RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
      ZSTD_clearAllDicts(cctx);
      cctx->prefixDict.dict = prefix;
      cctx->prefixDict.dictSize = prefixSize;
      cctx->prefixDict.dictContentType = dictContentType;
      return 0;
  }
  
  /*! ZSTD_CCtx_reset() :
   *  Also dumps dictionary */
  size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx, ZSTD_ResetDirective reset)
  {
      if ( (reset == ZSTD_reset_session_only)
        || (reset == ZSTD_reset_session_and_parameters) ) {
          cctx->streamStage = zcss_init;
          cctx->pledgedSrcSizePlusOne = 0;
      }
      if ( (reset == ZSTD_reset_parameters)
        || (reset == ZSTD_reset_session_and_parameters) ) {
          RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
          ZSTD_clearAllDicts(cctx);
          return ZSTD_CCtxParams_reset(&cctx->requestedParams);
      }
      return 0;
  }
  
  
  /** ZSTD_checkCParams() :
      control CParam values remain within authorized range.
      @return : 0, or an error code if one value is beyond authorized range */
  size_t ZSTD_checkCParams(ZSTD_compressionParameters cParams)
  {
      BOUNDCHECK(ZSTD_c_windowLog, (int)cParams.windowLog);
      BOUNDCHECK(ZSTD_c_chainLog,  (int)cParams.chainLog);
      BOUNDCHECK(ZSTD_c_hashLog,   (int)cParams.hashLog);
      BOUNDCHECK(ZSTD_c_searchLog, (int)cParams.searchLog);
      BOUNDCHECK(ZSTD_c_minMatch,  (int)cParams.minMatch);
      BOUNDCHECK(ZSTD_c_targetLength,(int)cParams.targetLength);
      BOUNDCHECK(ZSTD_c_strategy,  cParams.strategy);
      return 0;
  }
  
  /** ZSTD_clampCParams() :
   *  make CParam values within valid range.
   *  @return : valid CParams */
  static ZSTD_compressionParameters
  ZSTD_clampCParams(ZSTD_compressionParameters cParams)
  {
  #   define CLAMP_TYPE(cParam, val, type) {                                \
          ZSTD_bounds const bounds = ZSTD_cParam_getBounds(cParam);         \
          if ((int)val<bounds.lowerBound) val=(type)bounds.lowerBound;      \
          else if ((int)val>bounds.upperBound) val=(type)bounds.upperBound; \
      }
  #   define CLAMP(cParam, val) CLAMP_TYPE(cParam, val, unsigned)
      CLAMP(ZSTD_c_windowLog, cParams.windowLog);
      CLAMP(ZSTD_c_chainLog,  cParams.chainLog);
      CLAMP(ZSTD_c_hashLog,   cParams.hashLog);
      CLAMP(ZSTD_c_searchLog, cParams.searchLog);
      CLAMP(ZSTD_c_minMatch,  cParams.minMatch);
      CLAMP(ZSTD_c_targetLength,cParams.targetLength);
      CLAMP_TYPE(ZSTD_c_strategy,cParams.strategy, ZSTD_strategy);
      return cParams;
  }
  
  /** ZSTD_cycleLog() :
   *  condition for correct operation : hashLog > 1 */
  static U32 ZSTD_cycleLog(U32 hashLog, ZSTD_strategy strat)
  {
      U32 const btScale = ((U32)strat >= (U32)ZSTD_btlazy2);
      return hashLog - btScale;
  }
  
  /** ZSTD_adjustCParams_internal() :
   *  optimize `cPar` for a specified input (`srcSize` and `dictSize`).
   *  mostly downsize to reduce memory consumption and initialization latency.
   * `srcSize` can be ZSTD_CONTENTSIZE_UNKNOWN when not known.
   *  note : for the time being, `srcSize==0` means "unknown" too, for compatibility with older convention.
   *  condition : cPar is presumed validated (can be checked using ZSTD_checkCParams()). */
  static ZSTD_compressionParameters
  ZSTD_adjustCParams_internal(ZSTD_compressionParameters cPar,
                              unsigned long long srcSize,
                              size_t dictSize)
  {
      static const U64 minSrcSize = 513; /* (1<<9) + 1 */
      static const U64 maxWindowResize = 1ULL << (ZSTD_WINDOWLOG_MAX-1);
      assert(ZSTD_checkCParams(cPar)==0);
  
      if (dictSize && (srcSize+1<2) /* ZSTD_CONTENTSIZE_UNKNOWN and 0 mean "unknown" */ )
          srcSize = minSrcSize;  /* presumed small when there is a dictionary */
      else if (srcSize == 0)
          srcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* 0 == unknown : presumed large */
  
      /* resize windowLog if input is small enough, to use less memory */
      if ( (srcSize < maxWindowResize)
        && (dictSize < maxWindowResize) )  {
          U32 const tSize = (U32)(srcSize + dictSize);
          static U32 const hashSizeMin = 1 << ZSTD_HASHLOG_MIN;
          U32 const srcLog = (tSize < hashSizeMin) ? ZSTD_HASHLOG_MIN :
                              ZSTD_highbit32(tSize-1) + 1;
          if (cPar.windowLog > srcLog) cPar.windowLog = srcLog;
      }
      if (cPar.hashLog > cPar.windowLog+1) cPar.hashLog = cPar.windowLog+1;
      {   U32 const cycleLog = ZSTD_cycleLog(cPar.chainLog, cPar.strategy);
          if (cycleLog > cPar.windowLog)
              cPar.chainLog -= (cycleLog - cPar.windowLog);
      }
  
      if (cPar.windowLog < ZSTD_WINDOWLOG_ABSOLUTEMIN)
          cPar.windowLog = ZSTD_WINDOWLOG_ABSOLUTEMIN;  /* minimum wlog required for valid frame header */
  
      return cPar;
  }
  
  ZSTD_compressionParameters
  ZSTD_adjustCParams(ZSTD_compressionParameters cPar,
                     unsigned long long srcSize,
                     size_t dictSize)
  {
      cPar = ZSTD_clampCParams(cPar);   /* resulting cPar is necessarily valid (all parameters within range) */
      return ZSTD_adjustCParams_internal(cPar, srcSize, dictSize);
  }
  
  ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams(
          const ZSTD_CCtx_params* CCtxParams, U64 srcSizeHint, size_t dictSize)
  {
      ZSTD_compressionParameters cParams;
      if (srcSizeHint == ZSTD_CONTENTSIZE_UNKNOWN && CCtxParams->srcSizeHint > 0) {
        srcSizeHint = CCtxParams->srcSizeHint;
      }
      cParams = ZSTD_getCParams(CCtxParams->compressionLevel, srcSizeHint, dictSize);
      if (CCtxParams->ldmParams.enableLdm) cParams.windowLog = ZSTD_LDM_DEFAULT_WINDOW_LOG;
      if (CCtxParams->cParams.windowLog) cParams.windowLog = CCtxParams->cParams.windowLog;
      if (CCtxParams->cParams.hashLog) cParams.hashLog = CCtxParams->cParams.hashLog;
      if (CCtxParams->cParams.chainLog) cParams.chainLog = CCtxParams->cParams.chainLog;
      if (CCtxParams->cParams.searchLog) cParams.searchLog = CCtxParams->cParams.searchLog;
      if (CCtxParams->cParams.minMatch) cParams.minMatch = CCtxParams->cParams.minMatch;
      if (CCtxParams->cParams.targetLength) cParams.targetLength = CCtxParams->cParams.targetLength;
      if (CCtxParams->cParams.strategy) cParams.strategy = CCtxParams->cParams.strategy;
      assert(!ZSTD_checkCParams(cParams));
      return ZSTD_adjustCParams_internal(cParams, srcSizeHint, dictSize);
  }
  
  static size_t
  ZSTD_sizeof_matchState(const ZSTD_compressionParameters* const cParams,
                         const U32 forCCtx)
  {
      size_t const chainSize = (cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cParams->chainLog);
      size_t const hSize = ((size_t)1) << cParams->hashLog;
      U32    const hashLog3 = (forCCtx && cParams->minMatch==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
      size_t const h3Size = hashLog3 ? ((size_t)1) << hashLog3 : 0;
      /* We don't use ZSTD_cwksp_alloc_size() here because the tables aren't
       * surrounded by redzones in ASAN. */
      size_t const tableSpace = chainSize * sizeof(U32)
                              + hSize * sizeof(U32)
                              + h3Size * sizeof(U32);
      size_t const optPotentialSpace =
          ZSTD_cwksp_alloc_size((MaxML+1) * sizeof(U32))
        + ZSTD_cwksp_alloc_size((MaxLL+1) * sizeof(U32))
        + ZSTD_cwksp_alloc_size((MaxOff+1) * sizeof(U32))
        + ZSTD_cwksp_alloc_size((1<<Litbits) * sizeof(U32))
        + ZSTD_cwksp_alloc_size((ZSTD_OPT_NUM+1) * sizeof(ZSTD_match_t))
        + ZSTD_cwksp_alloc_size((ZSTD_OPT_NUM+1) * sizeof(ZSTD_optimal_t));
      size_t const optSpace = (forCCtx && (cParams->strategy >= ZSTD_btopt))
                                  ? optPotentialSpace
                                  : 0;
      DEBUGLOG(4, "chainSize: %u - hSize: %u - h3Size: %u",
                  (U32)chainSize, (U32)hSize, (U32)h3Size);
      return tableSpace + optSpace;
  }
  
  size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params)
  {
      RETURN_ERROR_IF(params->nbWorkers > 0, GENERIC, "Estimate CCtx size is supported for single-threaded compression only.");
      {   ZSTD_compressionParameters const cParams =
                  ZSTD_getCParamsFromCCtxParams(params, 0, 0);
          size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
          U32    const divider = (cParams.minMatch==3) ? 3 : 4;
          size_t const maxNbSeq = blockSize / divider;
          size_t const tokenSpace = ZSTD_cwksp_alloc_size(WILDCOPY_OVERLENGTH + blockSize)
                                  + ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(seqDef))
                                  + 3 * ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(BYTE));
          size_t const entropySpace = ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE);
          size_t const blockStateSpace = 2 * ZSTD_cwksp_alloc_size(sizeof(ZSTD_compressedBlockState_t));
          size_t const matchStateSize = ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 1);
  
          size_t const ldmSpace = ZSTD_ldm_getTableSize(params->ldmParams);
          size_t const ldmSeqSpace = ZSTD_cwksp_alloc_size(ZSTD_ldm_getMaxNbSeq(params->ldmParams, blockSize) * sizeof(rawSeq));
  
          size_t const neededSpace = entropySpace + blockStateSpace + tokenSpace +
                                     matchStateSize + ldmSpace + ldmSeqSpace;
          size_t const cctxSpace = ZSTD_cwksp_alloc_size(sizeof(ZSTD_CCtx));
  
          DEBUGLOG(5, "sizeof(ZSTD_CCtx) : %u", (U32)cctxSpace);
          DEBUGLOG(5, "estimate workspace : %u", (U32)neededSpace);
          return cctxSpace + neededSpace;
      }
  }
  
  size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams)
  {
      ZSTD_CCtx_params const params = ZSTD_makeCCtxParamsFromCParams(cParams);
      return ZSTD_estimateCCtxSize_usingCCtxParams(&params);
  }
  
  static size_t ZSTD_estimateCCtxSize_internal(int compressionLevel)
  {
      ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, 0);
      return ZSTD_estimateCCtxSize_usingCParams(cParams);
  }
  
  size_t ZSTD_estimateCCtxSize(int compressionLevel)
  {
      int level;
      size_t memBudget = 0;
      for (level=MIN(compressionLevel, 1); level<=compressionLevel; level++) {
          size_t const newMB = ZSTD_estimateCCtxSize_internal(level);
          if (newMB > memBudget) memBudget = newMB;
      }
      return memBudget;
  }
  
  size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params)
  {
      RETURN_ERROR_IF(params->nbWorkers > 0, GENERIC, "Estimate CCtx size is supported for single-threaded compression only.");
      {   ZSTD_compressionParameters const cParams =
                  ZSTD_getCParamsFromCCtxParams(params, 0, 0);
          size_t const CCtxSize = ZSTD_estimateCCtxSize_usingCCtxParams(params);
          size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
          size_t const inBuffSize = ((size_t)1 << cParams.windowLog) + blockSize;
          size_t const outBuffSize = ZSTD_compressBound(blockSize) + 1;
          size_t const streamingSize = ZSTD_cwksp_alloc_size(inBuffSize)
                                     + ZSTD_cwksp_alloc_size(outBuffSize);
  
          return CCtxSize + streamingSize;
      }
  }
  
  size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams)
  {
      ZSTD_CCtx_params const params = ZSTD_makeCCtxParamsFromCParams(cParams);
      return ZSTD_estimateCStreamSize_usingCCtxParams(&params);
  }
  
  static size_t ZSTD_estimateCStreamSize_internal(int compressionLevel)
  {
      ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, 0);
      return ZSTD_estimateCStreamSize_usingCParams(cParams);
  }
  
  size_t ZSTD_estimateCStreamSize(int compressionLevel)
  {
      int level;
      size_t memBudget = 0;
      for (level=MIN(compressionLevel, 1); level<=compressionLevel; level++) {
          size_t const newMB = ZSTD_estimateCStreamSize_internal(level);
          if (newMB > memBudget) memBudget = newMB;
      }
      return memBudget;
  }
  
  /* ZSTD_getFrameProgression():
   * tells how much data has been consumed (input) and produced (output) for current frame.
   * able to count progression inside worker threads (non-blocking mode).
   */
  ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx* cctx)
  {
  #ifdef ZSTD_MULTITHREAD
      if (cctx->appliedParams.nbWorkers > 0) {
          return ZSTDMT_getFrameProgression(cctx->mtctx);
      }
  #endif
      {   ZSTD_frameProgression fp;
          size_t const buffered = (cctx->inBuff == NULL) ? 0 :
                                  cctx->inBuffPos - cctx->inToCompress;
          if (buffered) assert(cctx->inBuffPos >= cctx->inToCompress);
          assert(buffered <= ZSTD_BLOCKSIZE_MAX);
          fp.ingested = cctx->consumedSrcSize + buffered;
          fp.consumed = cctx->consumedSrcSize;
          fp.produced = cctx->producedCSize;
          fp.flushed  = cctx->producedCSize;   /* simplified; some data might still be left within streaming output buffer */
          fp.currentJobID = 0;
          fp.nbActiveWorkers = 0;
          return fp;
  }   }
  
  /*! ZSTD_toFlushNow()
   *  Only useful for multithreading scenarios currently (nbWorkers >= 1).
   */
  size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx)
  {
  #ifdef ZSTD_MULTITHREAD
      if (cctx->appliedParams.nbWorkers > 0) {
          return ZSTDMT_toFlushNow(cctx->mtctx);
      }
  #endif
      (void)cctx;
      return 0;   /* over-simplification; could also check if context is currently running in streaming mode, and in which case, report how many bytes are left to be flushed within output buffer */
  }
  
  static void ZSTD_assertEqualCParams(ZSTD_compressionParameters cParams1,
                                      ZSTD_compressionParameters cParams2)
  {
      (void)cParams1;
      (void)cParams2;
      assert(cParams1.windowLog    == cParams2.windowLog);
      assert(cParams1.chainLog     == cParams2.chainLog);
      assert(cParams1.hashLog      == cParams2.hashLog);
      assert(cParams1.searchLog    == cParams2.searchLog);
      assert(cParams1.minMatch     == cParams2.minMatch);
      assert(cParams1.targetLength == cParams2.targetLength);
      assert(cParams1.strategy     == cParams2.strategy);
  }
  
  static void ZSTD_reset_compressedBlockState(ZSTD_compressedBlockState_t* bs)
  {
      int i;
      for (i = 0; i < ZSTD_REP_NUM; ++i)
          bs->rep[i] = repStartValue[i];
      bs->entropy.huf.repeatMode = HUF_repeat_none;
      bs->entropy.fse.offcode_repeatMode = FSE_repeat_none;
      bs->entropy.fse.matchlength_repeatMode = FSE_repeat_none;
      bs->entropy.fse.litlength_repeatMode = FSE_repeat_none;
  }
  
  /*! ZSTD_invalidateMatchState()
   *  Invalidate all the matches in the match finder tables.
   *  Requires nextSrc and base to be set (can be NULL).
   */
  static void ZSTD_invalidateMatchState(ZSTD_matchState_t* ms)
  {
      ZSTD_window_clear(&ms->window);
  
      ms->nextToUpdate = ms->window.dictLimit;
      ms->loadedDictEnd = 0;
      ms->opt.litLengthSum = 0;  /* force reset of btopt stats */
      ms->dictMatchState = NULL;
  }
  
  /**
   * Indicates whether this compression proceeds directly from user-provided
   * source buffer to user-provided destination buffer (ZSTDb_not_buffered), or
   * whether the context needs to buffer the input/output (ZSTDb_buffered).
   */
  typedef enum {
      ZSTDb_not_buffered,
      ZSTDb_buffered
  } ZSTD_buffered_policy_e;
  
  /**
   * Controls, for this matchState reset, whether the tables need to be cleared /
   * prepared for the coming compression (ZSTDcrp_makeClean), or whether the
   * tables can be left unclean (ZSTDcrp_leaveDirty), because we know that a
   * subsequent operation will overwrite the table space anyways (e.g., copying
   * the matchState contents in from a CDict).
   */
  typedef enum {
      ZSTDcrp_makeClean,
      ZSTDcrp_leaveDirty
  } ZSTD_compResetPolicy_e;
  
  /**
   * Controls, for this matchState reset, whether indexing can continue where it
   * left off (ZSTDirp_continue), or whether it needs to be restarted from zero
   * (ZSTDirp_reset).
   */
  typedef enum {
      ZSTDirp_continue,
      ZSTDirp_reset
  } ZSTD_indexResetPolicy_e;
  
  typedef enum {
      ZSTD_resetTarget_CDict,
      ZSTD_resetTarget_CCtx
  } ZSTD_resetTarget_e;
  
  static size_t
  ZSTD_reset_matchState(ZSTD_matchState_t* ms,
                        ZSTD_cwksp* ws,
                  const ZSTD_compressionParameters* cParams,
                  const ZSTD_compResetPolicy_e crp,
                  const ZSTD_indexResetPolicy_e forceResetIndex,
                  const ZSTD_resetTarget_e forWho)
  {
      size_t const chainSize = (cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cParams->chainLog);
      size_t const hSize = ((size_t)1) << cParams->hashLog;
      U32    const hashLog3 = ((forWho == ZSTD_resetTarget_CCtx) && cParams->minMatch==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
      size_t const h3Size = hashLog3 ? ((size_t)1) << hashLog3 : 0;
  
      DEBUGLOG(4, "reset indices : %u", forceResetIndex == ZSTDirp_reset);
      if (forceResetIndex == ZSTDirp_reset) {
          memset(&ms->window, 0, sizeof(ms->window));
          ms->window.dictLimit = 1;    /* start from 1, so that 1st position is valid */
          ms->window.lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
          ms->window.nextSrc = ms->window.base + 1;   /* see issue #1241 */
          ZSTD_cwksp_mark_tables_dirty(ws);
      }
  
      ms->hashLog3 = hashLog3;
  
      ZSTD_invalidateMatchState(ms);
  
      assert(!ZSTD_cwksp_reserve_failed(ws)); /* check that allocation hasn't already failed */
  
      ZSTD_cwksp_clear_tables(ws);
  
      DEBUGLOG(5, "reserving table space");
      /* table Space */
      ms->hashTable = (U32*)ZSTD_cwksp_reserve_table(ws, hSize * sizeof(U32));
      ms->chainTable = (U32*)ZSTD_cwksp_reserve_table(ws, chainSize * sizeof(U32));
      ms->hashTable3 = (U32*)ZSTD_cwksp_reserve_table(ws, h3Size * sizeof(U32));
      RETURN_ERROR_IF(ZSTD_cwksp_reserve_failed(ws), memory_allocation,
                      "failed a workspace allocation in ZSTD_reset_matchState");
  
      DEBUGLOG(4, "reset table : %u", crp!=ZSTDcrp_leaveDirty);
      if (crp!=ZSTDcrp_leaveDirty) {
          /* reset tables only */
          ZSTD_cwksp_clean_tables(ws);
      }
  
      /* opt parser space */
      if ((forWho == ZSTD_resetTarget_CCtx) && (cParams->strategy >= ZSTD_btopt)) {
          DEBUGLOG(4, "reserving optimal parser space");
          ms->opt.litFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (1<<Litbits) * sizeof(unsigned));
          ms->opt.litLengthFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxLL+1) * sizeof(unsigned));
          ms->opt.matchLengthFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxML+1) * sizeof(unsigned));
          ms->opt.offCodeFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxOff+1) * sizeof(unsigned));
          ms->opt.matchTable = (ZSTD_match_t*)ZSTD_cwksp_reserve_aligned(ws, (ZSTD_OPT_NUM+1) * sizeof(ZSTD_match_t));
          ms->opt.priceTable = (ZSTD_optimal_t*)ZSTD_cwksp_reserve_aligned(ws, (ZSTD_OPT_NUM+1) * sizeof(ZSTD_optimal_t));
      }
  
      ms->cParams = *cParams;
  
      RETURN_ERROR_IF(ZSTD_cwksp_reserve_failed(ws), memory_allocation,
                      "failed a workspace allocation in ZSTD_reset_matchState");
  
      return 0;
  }
  
  /* ZSTD_indexTooCloseToMax() :
   * minor optimization : prefer memset() rather than reduceIndex()
   * which is measurably slow in some circumstances (reported for Visual Studio).
   * Works when re-using a context for a lot of smallish inputs :
   * if all inputs are smaller than ZSTD_INDEXOVERFLOW_MARGIN,
   * memset() will be triggered before reduceIndex().
   */
  #define ZSTD_INDEXOVERFLOW_MARGIN (16 MB)
  static int ZSTD_indexTooCloseToMax(ZSTD_window_t w)
  {
      return (size_t)(w.nextSrc - w.base) > (ZSTD_CURRENT_MAX - ZSTD_INDEXOVERFLOW_MARGIN);
  }
  
  /*! ZSTD_resetCCtx_internal() :
      note : `params` are assumed fully validated at this stage */
  static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
                                        ZSTD_CCtx_params params,
                                        U64 const pledgedSrcSize,
                                        ZSTD_compResetPolicy_e const crp,
                                        ZSTD_buffered_policy_e const zbuff)
  {
      ZSTD_cwksp* const ws = &zc->workspace;
      DEBUGLOG(4, "ZSTD_resetCCtx_internal: pledgedSrcSize=%u, wlog=%u",
                  (U32)pledgedSrcSize, params.cParams.windowLog);
      assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
  
      zc->isFirstBlock = 1;
  
      if (params.ldmParams.enableLdm) {
          /* Adjust long distance matching parameters */
          ZSTD_ldm_adjustParameters(&params.ldmParams, &params.cParams);
          assert(params.ldmParams.hashLog >= params.ldmParams.bucketSizeLog);
          assert(params.ldmParams.hashRateLog < 32);
          zc->ldmState.hashPower = ZSTD_rollingHash_primePower(params.ldmParams.minMatchLength);
      }
  
      {   size_t const windowSize = MAX(1, (size_t)MIN(((U64)1 << params.cParams.windowLog), pledgedSrcSize));
          size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
          U32    const divider = (params.cParams.minMatch==3) ? 3 : 4;
          size_t const maxNbSeq = blockSize / divider;
          size_t const tokenSpace = ZSTD_cwksp_alloc_size(WILDCOPY_OVERLENGTH + blockSize)
                                  + ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(seqDef))
                                  + 3 * ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(BYTE));
          size_t const buffOutSize = (zbuff==ZSTDb_buffered) ? ZSTD_compressBound(blockSize)+1 : 0;
          size_t const buffInSize = (zbuff==ZSTDb_buffered) ? windowSize + blockSize : 0;
          size_t const matchStateSize = ZSTD_sizeof_matchState(&params.cParams, /* forCCtx */ 1);
          size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(params.ldmParams, blockSize);
  
          ZSTD_indexResetPolicy_e needsIndexReset = ZSTDirp_continue;
  
          if (ZSTD_indexTooCloseToMax(zc->blockState.matchState.window)) {
              needsIndexReset = ZSTDirp_reset;
          }
  
          ZSTD_cwksp_bump_oversized_duration(ws, 0);
  
          /* Check if workspace is large enough, alloc a new one if needed */
          {   size_t const cctxSpace = zc->staticSize ? ZSTD_cwksp_alloc_size(sizeof(ZSTD_CCtx)) : 0;
              size_t const entropySpace = ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE);
              size_t const blockStateSpace = 2 * ZSTD_cwksp_alloc_size(sizeof(ZSTD_compressedBlockState_t));
              size_t const bufferSpace = ZSTD_cwksp_alloc_size(buffInSize) + ZSTD_cwksp_alloc_size(buffOutSize);
              size_t const ldmSpace = ZSTD_ldm_getTableSize(params.ldmParams);
              size_t const ldmSeqSpace = ZSTD_cwksp_alloc_size(maxNbLdmSeq * sizeof(rawSeq));
  
              size_t const neededSpace =
                  cctxSpace +
                  entropySpace +
                  blockStateSpace +
                  ldmSpace +
                  ldmSeqSpace +
                  matchStateSize +
                  tokenSpace +
                  bufferSpace;
  
              int const workspaceTooSmall = ZSTD_cwksp_sizeof(ws) < neededSpace;
              int const workspaceWasteful = ZSTD_cwksp_check_wasteful(ws, neededSpace);
  
              DEBUGLOG(4, "Need %zuKB workspace, including %zuKB for match state, and %zuKB for buffers",
                          neededSpace>>10, matchStateSize>>10, bufferSpace>>10);
              DEBUGLOG(4, "windowSize: %zu - blockSize: %zu", windowSize, blockSize);
  
              if (workspaceTooSmall || workspaceWasteful) {
                  DEBUGLOG(4, "Resize workspaceSize from %zuKB to %zuKB",
                              ZSTD_cwksp_sizeof(ws) >> 10,
                              neededSpace >> 10);
  
                  RETURN_ERROR_IF(zc->staticSize, memory_allocation, "static cctx : no resize");
  
                  needsIndexReset = ZSTDirp_reset;
  
                  ZSTD_cwksp_free(ws, zc->customMem);
                  FORWARD_IF_ERROR(ZSTD_cwksp_create(ws, neededSpace, zc->customMem));
  
                  DEBUGLOG(5, "reserving object space");
                  /* Statically sized space.
                   * entropyWorkspace never moves,
                   * though prev/next block swap places */
                  assert(ZSTD_cwksp_check_available(ws, 2 * sizeof(ZSTD_compressedBlockState_t)));
                  zc->blockState.prevCBlock = (ZSTD_compressedBlockState_t*) ZSTD_cwksp_reserve_object(ws, sizeof(ZSTD_compressedBlockState_t));
                  RETURN_ERROR_IF(zc->blockState.prevCBlock == NULL, memory_allocation, "couldn't allocate prevCBlock");
                  zc->blockState.nextCBlock = (ZSTD_compressedBlockState_t*) ZSTD_cwksp_reserve_object(ws, sizeof(ZSTD_compressedBlockState_t));
                  RETURN_ERROR_IF(zc->blockState.nextCBlock == NULL, memory_allocation, "couldn't allocate nextCBlock");
                  zc->entropyWorkspace = (U32*) ZSTD_cwksp_reserve_object(ws, HUF_WORKSPACE_SIZE);
                  RETURN_ERROR_IF(zc->blockState.nextCBlock == NULL, memory_allocation, "couldn't allocate entropyWorkspace");
          }   }
  
          ZSTD_cwksp_clear(ws);
  
          /* init params */
          zc->appliedParams = params;
          zc->blockState.matchState.cParams = params.cParams;
          zc->pledgedSrcSizePlusOne = pledgedSrcSize+1;
          zc->consumedSrcSize = 0;
          zc->producedCSize = 0;
          if (pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN)
              zc->appliedParams.fParams.contentSizeFlag = 0;
          DEBUGLOG(4, "pledged content size : %u ; flag : %u",
              (unsigned)pledgedSrcSize, zc->appliedParams.fParams.contentSizeFlag);
          zc->blockSize = blockSize;
  
          XXH64_reset(&zc->xxhState, 0);
          zc->stage = ZSTDcs_init;
          zc->dictID = 0;
  
          ZSTD_reset_compressedBlockState(zc->blockState.prevCBlock);
  
          /* ZSTD_wildcopy() is used to copy into the literals buffer,
           * so we have to oversize the buffer by WILDCOPY_OVERLENGTH bytes.
           */
          zc->seqStore.litStart = ZSTD_cwksp_reserve_buffer(ws, blockSize + WILDCOPY_OVERLENGTH);
          zc->seqStore.maxNbLit = blockSize;
  
          /* buffers */
          zc->inBuffSize = buffInSize;
          zc->inBuff = (char*)ZSTD_cwksp_reserve_buffer(ws, buffInSize);
          zc->outBuffSize = buffOutSize;
          zc->outBuff = (char*)ZSTD_cwksp_reserve_buffer(ws, buffOutSize);
  
          /* ldm bucketOffsets table */
          if (params.ldmParams.enableLdm) {
              /* TODO: avoid memset? */
              size_t const ldmBucketSize =
                    ((size_t)1) << (params.ldmParams.hashLog -
                                    params.ldmParams.bucketSizeLog);
              zc->ldmState.bucketOffsets = ZSTD_cwksp_reserve_buffer(ws, ldmBucketSize);
              memset(zc->ldmState.bucketOffsets, 0, ldmBucketSize);
          }
  
          /* sequences storage */
          ZSTD_referenceExternalSequences(zc, NULL, 0);
          zc->seqStore.maxNbSeq = maxNbSeq;
          zc->seqStore.llCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
          zc->seqStore.mlCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
          zc->seqStore.ofCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
          zc->seqStore.sequencesStart = (seqDef*)ZSTD_cwksp_reserve_aligned(ws, maxNbSeq * sizeof(seqDef));
  
          FORWARD_IF_ERROR(ZSTD_reset_matchState(
              &zc->blockState.matchState,
              ws,
              &params.cParams,
              crp,
              needsIndexReset,
              ZSTD_resetTarget_CCtx));
  
          /* ldm hash table */
          if (params.ldmParams.enableLdm) {
              /* TODO: avoid memset? */
              size_t const ldmHSize = ((size_t)1) << params.ldmParams.hashLog;
              zc->ldmState.hashTable = (ldmEntry_t*)ZSTD_cwksp_reserve_aligned(ws, ldmHSize * sizeof(ldmEntry_t));
              memset(zc->ldmState.hashTable, 0, ldmHSize * sizeof(ldmEntry_t));
              zc->ldmSequences = (rawSeq*)ZSTD_cwksp_reserve_aligned(ws, maxNbLdmSeq * sizeof(rawSeq));
              zc->maxNbLdmSequences = maxNbLdmSeq;
  
              memset(&zc->ldmState.window, 0, sizeof(zc->ldmState.window));
              ZSTD_window_clear(&zc->ldmState.window);
          }
  
          DEBUGLOG(3, "wksp: finished allocating, %zd bytes remain available", ZSTD_cwksp_available_space(ws));
  
          return 0;
      }
  }
  
  /* ZSTD_invalidateRepCodes() :
   * ensures next compression will not use repcodes from previous block.
   * Note : only works with regular variant;
   *        do not use with extDict variant ! */
  void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx) {
      int i;
      for (i=0; i<ZSTD_REP_NUM; i++) cctx->blockState.prevCBlock->rep[i] = 0;
      assert(!ZSTD_window_hasExtDict(cctx->blockState.matchState.window));
  }
  
  /* These are the approximate sizes for each strategy past which copying the
   * dictionary tables into the working context is faster than using them
   * in-place.
   */
  static const size_t attachDictSizeCutoffs[ZSTD_STRATEGY_MAX+1] = {
      8 KB,  /* unused */
      8 KB,  /* ZSTD_fast */
      16 KB, /* ZSTD_dfast */
      32 KB, /* ZSTD_greedy */
      32 KB, /* ZSTD_lazy */
      32 KB, /* ZSTD_lazy2 */
      32 KB, /* ZSTD_btlazy2 */
      32 KB, /* ZSTD_btopt */
      8 KB,  /* ZSTD_btultra */
      8 KB   /* ZSTD_btultra2 */
  };
  
  static int ZSTD_shouldAttachDict(const ZSTD_CDict* cdict,
                                   const ZSTD_CCtx_params* params,
                                   U64 pledgedSrcSize)
  {
      size_t cutoff = attachDictSizeCutoffs[cdict->matchState.cParams.strategy];
      return ( pledgedSrcSize <= cutoff
            || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
            || params->attachDictPref == ZSTD_dictForceAttach )
          && params->attachDictPref != ZSTD_dictForceCopy
          && !params->forceWindow; /* dictMatchState isn't correctly
                                   * handled in _enforceMaxDist */
  }
  
  static size_t
  ZSTD_resetCCtx_byAttachingCDict(ZSTD_CCtx* cctx,
                          const ZSTD_CDict* cdict,
                          ZSTD_CCtx_params params,
                          U64 pledgedSrcSize,
                          ZSTD_buffered_policy_e zbuff)
  {
      {   const ZSTD_compressionParameters* const cdict_cParams = &cdict->matchState.cParams;
          unsigned const windowLog = params.cParams.windowLog;
          assert(windowLog != 0);
          /* Resize working context table params for input only, since the dict
           * has its own tables. */
          params.cParams = ZSTD_adjustCParams_internal(*cdict_cParams, pledgedSrcSize, 0);
          params.cParams.windowLog = windowLog;
          FORWARD_IF_ERROR(ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
                                                   ZSTDcrp_makeClean, zbuff));
          assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
      }
  
      {   const U32 cdictEnd = (U32)( cdict->matchState.window.nextSrc
                                    - cdict->matchState.window.base);
          const U32 cdictLen = cdictEnd - cdict->matchState.window.dictLimit;
          if (cdictLen == 0) {
              /* don't even attach dictionaries with no contents */
              DEBUGLOG(4, "skipping attaching empty dictionary");
          } else {
              DEBUGLOG(4, "attaching dictionary into context");
              cctx->blockState.matchState.dictMatchState = &cdict->matchState;
  
              /* prep working match state so dict matches never have negative indices
               * when they are translated to the working context's index space. */
              if (cctx->blockState.matchState.window.dictLimit < cdictEnd) {
                  cctx->blockState.matchState.window.nextSrc =
                      cctx->blockState.matchState.window.base + cdictEnd;
                  ZSTD_window_clear(&cctx->blockState.matchState.window);
              }
              /* loadedDictEnd is expressed within the referential of the active context */
              cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
      }   }
  
      cctx->dictID = cdict->dictID;
  
      /* copy block state */
      memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
  
      return 0;
  }
  
  static size_t ZSTD_resetCCtx_byCopyingCDict(ZSTD_CCtx* cctx,
                              const ZSTD_CDict* cdict,
                              ZSTD_CCtx_params params,
                              U64 pledgedSrcSize,
                              ZSTD_buffered_policy_e zbuff)
  {
      const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
  
      DEBUGLOG(4, "copying dictionary into context");
  
      {   unsigned const windowLog = params.cParams.windowLog;
          assert(windowLog != 0);
          /* Copy only compression parameters related to tables. */
          params.cParams = *cdict_cParams;
          params.cParams.windowLog = windowLog;
          FORWARD_IF_ERROR(ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
                                                   ZSTDcrp_leaveDirty, zbuff));
          assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
          assert(cctx->appliedParams.cParams.hashLog == cdict_cParams->hashLog);
          assert(cctx->appliedParams.cParams.chainLog == cdict_cParams->chainLog);
      }
  
      ZSTD_cwksp_mark_tables_dirty(&cctx->workspace);
  
      /* copy tables */
      {   size_t const chainSize = (cdict_cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict_cParams->chainLog);
          size_t const hSize =  (size_t)1 << cdict_cParams->hashLog;
  
          memcpy(cctx->blockState.matchState.hashTable,
                 cdict->matchState.hashTable,
                 hSize * sizeof(U32));
          memcpy(cctx->blockState.matchState.chainTable,
                 cdict->matchState.chainTable,
                 chainSize * sizeof(U32));
      }
  
      /* Zero the hashTable3, since the cdict never fills it */
      {   int const h3log = cctx->blockState.matchState.hashLog3;
          size_t const h3Size = h3log ? ((size_t)1 << h3log) : 0;
          assert(cdict->matchState.hashLog3 == 0);
          memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
      }
  
      ZSTD_cwksp_mark_tables_clean(&cctx->workspace);
  
      /* copy dictionary offsets */
      {   ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
          ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
          dstMatchState->window       = srcMatchState->window;
          dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
          dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
      }
  
      cctx->dictID = cdict->dictID;
  
      /* copy block state */
      memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
  
      return 0;
  }
  
  /* We have a choice between copying the dictionary context into the working
   * context, or referencing the dictionary context from the working context
   * in-place. We decide here which strategy to use. */
  static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
                              const ZSTD_CDict* cdict,
                              const ZSTD_CCtx_params* params,
                              U64 pledgedSrcSize,
                              ZSTD_buffered_policy_e zbuff)
  {
  
      DEBUGLOG(4, "ZSTD_resetCCtx_usingCDict (pledgedSrcSize=%u)",
                  (unsigned)pledgedSrcSize);
  
      if (ZSTD_shouldAttachDict(cdict, params, pledgedSrcSize)) {
          return ZSTD_resetCCtx_byAttachingCDict(
              cctx, cdict, *params, pledgedSrcSize, zbuff);
      } else {
          return ZSTD_resetCCtx_byCopyingCDict(
              cctx, cdict, *params, pledgedSrcSize, zbuff);
      }
  }
  
  /*! ZSTD_copyCCtx_internal() :
   *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
   *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
   *  The "context", in this case, refers to the hash and chain tables,
   *  entropy tables, and dictionary references.
   * `windowLog` value is enforced if != 0, otherwise value is copied from srcCCtx.
   * @return : 0, or an error code */
  static size_t ZSTD_copyCCtx_internal(ZSTD_CCtx* dstCCtx,
                              const ZSTD_CCtx* srcCCtx,
                              ZSTD_frameParameters fParams,
                              U64 pledgedSrcSize,
                              ZSTD_buffered_policy_e zbuff)
  {
      DEBUGLOG(5, "ZSTD_copyCCtx_internal");
      RETURN_ERROR_IF(srcCCtx->stage!=ZSTDcs_init, stage_wrong);
  
      memcpy(&dstCCtx->customMem, &srcCCtx->customMem, sizeof(ZSTD_customMem));
      {   ZSTD_CCtx_params params = dstCCtx->requestedParams;
          /* Copy only compression parameters related to tables. */
          params.cParams = srcCCtx->appliedParams.cParams;
          params.fParams = fParams;
          ZSTD_resetCCtx_internal(dstCCtx, params, pledgedSrcSize,
                                  ZSTDcrp_leaveDirty, zbuff);
          assert(dstCCtx->appliedParams.cParams.windowLog == srcCCtx->appliedParams.cParams.windowLog);
          assert(dstCCtx->appliedParams.cParams.strategy == srcCCtx->appliedParams.cParams.strategy);
          assert(dstCCtx->appliedParams.cParams.hashLog == srcCCtx->appliedParams.cParams.hashLog);
          assert(dstCCtx->appliedParams.cParams.chainLog == srcCCtx->appliedParams.cParams.chainLog);
          assert(dstCCtx->blockState.matchState.hashLog3 == srcCCtx->blockState.matchState.hashLog3);
      }
  
      ZSTD_cwksp_mark_tables_dirty(&dstCCtx->workspace);
  
      /* copy tables */
      {   size_t const chainSize = (srcCCtx->appliedParams.cParams.strategy == ZSTD_fast) ? 0 : ((size_t)1 << srcCCtx->appliedParams.cParams.chainLog);
          size_t const hSize =  (size_t)1 << srcCCtx->appliedParams.cParams.hashLog;
          int const h3log = srcCCtx->blockState.matchState.hashLog3;
          size_t const h3Size = h3log ? ((size_t)1 << h3log) : 0;
  
          memcpy(dstCCtx->blockState.matchState.hashTable,
                 srcCCtx->blockState.matchState.hashTable,
                 hSize * sizeof(U32));
          memcpy(dstCCtx->blockState.matchState.chainTable,
                 srcCCtx->blockState.matchState.chainTable,
                 chainSize * sizeof(U32));
          memcpy(dstCCtx->blockState.matchState.hashTable3,
                 srcCCtx->blockState.matchState.hashTable3,
                 h3Size * sizeof(U32));
      }
  
      ZSTD_cwksp_mark_tables_clean(&dstCCtx->workspace);
  
      /* copy dictionary offsets */
      {
          const ZSTD_matchState_t* srcMatchState = &srcCCtx->blockState.matchState;
          ZSTD_matchState_t* dstMatchState = &dstCCtx->blockState.matchState;
          dstMatchState->window       = srcMatchState->window;
          dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
          dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
      }
      dstCCtx->dictID = srcCCtx->dictID;
  
      /* copy block state */
      memcpy(dstCCtx->blockState.prevCBlock, srcCCtx->blockState.prevCBlock, sizeof(*srcCCtx->blockState.prevCBlock));
  
      return 0;
  }
  
  /*! ZSTD_copyCCtx() :
   *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
   *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
   *  pledgedSrcSize==0 means "unknown".
  *   @return : 0, or an error code */
  size_t ZSTD_copyCCtx(ZSTD_CCtx* dstCCtx, const ZSTD_CCtx* srcCCtx, unsigned long long pledgedSrcSize)
  {
      ZSTD_frameParameters fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
      ZSTD_buffered_policy_e const zbuff = (ZSTD_buffered_policy_e)(srcCCtx->inBuffSize>0);
      ZSTD_STATIC_ASSERT((U32)ZSTDb_buffered==1);
      if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;
      fParams.contentSizeFlag = (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN);
  
      return ZSTD_copyCCtx_internal(dstCCtx, srcCCtx,
                                  fParams, pledgedSrcSize,
                                  zbuff);
  }
  
  
  #define ZSTD_ROWSIZE 16
  /*! ZSTD_reduceTable() :
   *  reduce table indexes by `reducerValue`, or squash to zero.
   *  PreserveMark preserves "unsorted mark" for btlazy2 strategy.
   *  It must be set to a clear 0/1 value, to remove branch during inlining.
   *  Presume table size is a multiple of ZSTD_ROWSIZE
   *  to help auto-vectorization */
  FORCE_INLINE_TEMPLATE void
  ZSTD_reduceTable_internal (U32* const table, U32 const size, U32 const reducerValue, int const preserveMark)
  {
      int const nbRows = (int)size / ZSTD_ROWSIZE;
      int cellNb = 0;
      int rowNb;
      assert((size & (ZSTD_ROWSIZE-1)) == 0);  /* multiple of ZSTD_ROWSIZE */
      assert(size < (1U<<31));   /* can be casted to int */
  
  #if defined (MEMORY_SANITIZER) && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE)
      /* To validate that the table re-use logic is sound, and that we don't
       * access table space that we haven't cleaned, we re-"poison" the table
       * space every time we mark it dirty.
       *
       * This function however is intended to operate on those dirty tables and
       * re-clean them. So when this function is used correctly, we can unpoison
       * the memory it operated on. This introduces a blind spot though, since
       * if we now try to operate on __actually__ poisoned memory, we will not
       * detect that. */
      __msan_unpoison(table, size * sizeof(U32));
  #endif
  
      for (rowNb=0 ; rowNb < nbRows ; rowNb++) {
          int column;
          for (column=0; column<ZSTD_ROWSIZE; column++) {
              if (preserveMark) {
                  U32 const adder = (table[cellNb] == ZSTD_DUBT_UNSORTED_MARK) ? reducerValue : 0;
                  table[cellNb] += adder;
              }
              if (table[cellNb] < reducerValue) table[cellNb] = 0;
              else table[cellNb] -= reducerValue;
              cellNb++;
      }   }
  }
  
  static void ZSTD_reduceTable(U32* const table, U32 const size, U32 const reducerValue)
  {
      ZSTD_reduceTable_internal(table, size, reducerValue, 0);
  }
  
  static void ZSTD_reduceTable_btlazy2(U32* const table, U32 const size, U32 const reducerValue)
  {
      ZSTD_reduceTable_internal(table, size, reducerValue, 1);
  }
  
  /*! ZSTD_reduceIndex() :
  *   rescale all indexes to avoid future overflow (indexes are U32) */
  static void ZSTD_reduceIndex (ZSTD_matchState_t* ms, ZSTD_CCtx_params const* params, const U32 reducerValue)
  {
      {   U32 const hSize = (U32)1 << params->cParams.hashLog;
          ZSTD_reduceTable(ms->hashTable, hSize, reducerValue);
      }
  
      if (params->cParams.strategy != ZSTD_fast) {
          U32 const chainSize = (U32)1 << params->cParams.chainLog;
          if (params->cParams.strategy == ZSTD_btlazy2)
              ZSTD_reduceTable_btlazy2(ms->chainTable, chainSize, reducerValue);
          else
              ZSTD_reduceTable(ms->chainTable, chainSize, reducerValue);
      }
  
      if (ms->hashLog3) {
          U32 const h3Size = (U32)1 << ms->hashLog3;
          ZSTD_reduceTable(ms->hashTable3, h3Size, reducerValue);
      }
  }
  
  
  /*-*******************************************************
  *  Block entropic compression
  *********************************************************/
  
  /* See doc/zstd_compression_format.md for detailed format description */
  
  static size_t ZSTD_noCompressBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize, U32 lastBlock)
  {
      U32 const cBlockHeader24 = lastBlock + (((U32)bt_raw)<<1) + (U32)(srcSize << 3);
      RETURN_ERROR_IF(srcSize + ZSTD_blockHeaderSize > dstCapacity,
                      dstSize_tooSmall);
      MEM_writeLE24(dst, cBlockHeader24);
      memcpy((BYTE*)dst + ZSTD_blockHeaderSize, src, srcSize);
      return ZSTD_blockHeaderSize + srcSize;
  }
  
  void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
  {
      const seqDef* const sequences = seqStorePtr->sequencesStart;
      BYTE* const llCodeTable = seqStorePtr->llCode;
      BYTE* const ofCodeTable = seqStorePtr->ofCode;
      BYTE* const mlCodeTable = seqStorePtr->mlCode;
      U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
      U32 u;
      assert(nbSeq <= seqStorePtr->maxNbSeq);
      for (u=0; u<nbSeq; u++) {
          U32 const llv = sequences[u].litLength;
          U32 const mlv = sequences[u].matchLength;
          llCodeTable[u] = (BYTE)ZSTD_LLcode(llv);
          ofCodeTable[u] = (BYTE)ZSTD_highbit32(sequences[u].offset);
          mlCodeTable[u] = (BYTE)ZSTD_MLcode(mlv);
      }
      if (seqStorePtr->longLengthID==1)
          llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
      if (seqStorePtr->longLengthID==2)
          mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
  }
  
  static int ZSTD_disableLiteralsCompression(const ZSTD_CCtx_params* cctxParams)
  {
      switch (cctxParams->literalCompressionMode) {
      case ZSTD_lcm_huffman:
          return 0;
      case ZSTD_lcm_uncompressed:
          return 1;
      default:
          assert(0 /* impossible: pre-validated */);
          /* fall-through */
      case ZSTD_lcm_auto:
          return (cctxParams->cParams.strategy == ZSTD_fast) && (cctxParams->cParams.targetLength > 0);
      }
  }
  
  /* ZSTD_compressSequences_internal():
   * actually compresses both literals and sequences */
  MEM_STATIC size_t
  ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
                            const ZSTD_entropyCTables_t* prevEntropy,
                                  ZSTD_entropyCTables_t* nextEntropy,
                            const ZSTD_CCtx_params* cctxParams,
                                  void* dst, size_t dstCapacity,
                                  void* entropyWorkspace, size_t entropyWkspSize,
                            const int bmi2)
  {
      const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN;
      ZSTD_strategy const strategy = cctxParams->cParams.strategy;
      unsigned count[MaxSeq+1];
      FSE_CTable* CTable_LitLength = nextEntropy->fse.litlengthCTable;
      FSE_CTable* CTable_OffsetBits = nextEntropy->fse.offcodeCTable;
      FSE_CTable* CTable_MatchLength = nextEntropy->fse.matchlengthCTable;
      U32 LLtype, Offtype, MLtype;   /* compressed, raw or rle */
      const seqDef* const sequences = seqStorePtr->sequencesStart;
      const BYTE* const ofCodeTable = seqStorePtr->ofCode;
      const BYTE* const llCodeTable = seqStorePtr->llCode;
      const BYTE* const mlCodeTable = seqStorePtr->mlCode;
      BYTE* const ostart = (BYTE*)dst;
      BYTE* const oend = ostart + dstCapacity;
      BYTE* op = ostart;
      size_t const nbSeq = (size_t)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
      BYTE* seqHead;
      BYTE* lastNCount = NULL;
  
      DEBUGLOG(5, "ZSTD_compressSequences_internal (nbSeq=%zu)", nbSeq);
      ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<<MAX(MLFSELog,LLFSELog)));
  
      /* Compress literals */
      {   const BYTE* const literals = seqStorePtr->litStart;
          size_t const litSize = (size_t)(seqStorePtr->lit - literals);
          size_t const cSize = ZSTD_compressLiterals(
                                      &prevEntropy->huf, &nextEntropy->huf,
                                      cctxParams->cParams.strategy,
                                      ZSTD_disableLiteralsCompression(cctxParams),
                                      op, dstCapacity,
                                      literals, litSize,
                                      entropyWorkspace, entropyWkspSize,
                                      bmi2);
          FORWARD_IF_ERROR(cSize);
          assert(cSize <= dstCapacity);
          op += cSize;
      }
  
      /* Sequences Header */
      RETURN_ERROR_IF((oend-op) < 3 /*max nbSeq Size*/ + 1 /*seqHead*/,
                      dstSize_tooSmall);
      if (nbSeq < 128) {
          *op++ = (BYTE)nbSeq;
      } else if (nbSeq < LONGNBSEQ) {
          op[0] = (BYTE)((nbSeq>>8) + 0x80);
          op[1] = (BYTE)nbSeq;
          op+=2;
      } else {
          op[0]=0xFF;
          MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ));
          op+=3;
      }
      assert(op <= oend);
      if (nbSeq==0) {
          /* Copy the old tables over as if we repeated them */
          memcpy(&nextEntropy->fse, &prevEntropy->fse, sizeof(prevEntropy->fse));
          return (size_t)(op - ostart);
      }
  
      /* seqHead : flags for FSE encoding type */
      seqHead = op++;
      assert(op <= oend);
  
      /* convert length/distances into codes */
      ZSTD_seqToCodes(seqStorePtr);
      /* build CTable for Literal Lengths */
      {   unsigned max = MaxLL;
          size_t const mostFrequent = HIST_countFast_wksp(count, &max, llCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);   /* can't fail */
          DEBUGLOG(5, "Building LL table");
          nextEntropy->fse.litlength_repeatMode = prevEntropy->fse.litlength_repeatMode;
          LLtype = ZSTD_selectEncodingType(&nextEntropy->fse.litlength_repeatMode,
                                          count, max, mostFrequent, nbSeq,
                                          LLFSELog, prevEntropy->fse.litlengthCTable,
                                          LL_defaultNorm, LL_defaultNormLog,
                                          ZSTD_defaultAllowed, strategy);
          assert(set_basic < set_compressed && set_rle < set_compressed);
          assert(!(LLtype < set_compressed && nextEntropy->fse.litlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
          {   size_t const countSize = ZSTD_buildCTable(
                  op, (size_t)(oend - op),
                  CTable_LitLength, LLFSELog, (symbolEncodingType_e)LLtype,
                  count, max, llCodeTable, nbSeq,
                  LL_defaultNorm, LL_defaultNormLog, MaxLL,
                  prevEntropy->fse.litlengthCTable,
                  sizeof(prevEntropy->fse.litlengthCTable),
                  entropyWorkspace, entropyWkspSize);
              FORWARD_IF_ERROR(countSize);
              if (LLtype == set_compressed)
                  lastNCount = op;
              op += countSize;
              assert(op <= oend);
      }   }
      /* build CTable for Offsets */
      {   unsigned max = MaxOff;
          size_t const mostFrequent = HIST_countFast_wksp(
              count, &max, ofCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);  /* can't fail */
          /* We can only use the basic table if max <= DefaultMaxOff, otherwise the offsets are too large */
          ZSTD_defaultPolicy_e const defaultPolicy = (max <= DefaultMaxOff) ? ZSTD_defaultAllowed : ZSTD_defaultDisallowed;
          DEBUGLOG(5, "Building OF table");
          nextEntropy->fse.offcode_repeatMode = prevEntropy->fse.offcode_repeatMode;
          Offtype = ZSTD_selectEncodingType(&nextEntropy->fse.offcode_repeatMode,
                                          count, max, mostFrequent, nbSeq,
                                          OffFSELog, prevEntropy->fse.offcodeCTable,
                                          OF_defaultNorm, OF_defaultNormLog,
                                          defaultPolicy, strategy);
          assert(!(Offtype < set_compressed && nextEntropy->fse.offcode_repeatMode != FSE_repeat_none)); /* We don't copy tables */
          {   size_t const countSize = ZSTD_buildCTable(
                  op, (size_t)(oend - op),
                  CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)Offtype,
                  count, max, ofCodeTable, nbSeq,
                  OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
                  prevEntropy->fse.offcodeCTable,
                  sizeof(prevEntropy->fse.offcodeCTable),
                  entropyWorkspace, entropyWkspSize);
              FORWARD_IF_ERROR(countSize);
              if (Offtype == set_compressed)
                  lastNCount = op;
              op += countSize;
              assert(op <= oend);
      }   }
      /* build CTable for MatchLengths */
      {   unsigned max = MaxML;
          size_t const mostFrequent = HIST_countFast_wksp(
              count, &max, mlCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);   /* can't fail */
          DEBUGLOG(5, "Building ML table (remaining space : %i)", (int)(oend-op));
          nextEntropy->fse.matchlength_repeatMode = prevEntropy->fse.matchlength_repeatMode;
          MLtype = ZSTD_selectEncodingType(&nextEntropy->fse.matchlength_repeatMode,
                                          count, max, mostFrequent, nbSeq,
                                          MLFSELog, prevEntropy->fse.matchlengthCTable,
                                          ML_defaultNorm, ML_defaultNormLog,
                                          ZSTD_defaultAllowed, strategy);
          assert(!(MLtype < set_compressed && nextEntropy->fse.matchlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
          {   size_t const countSize = ZSTD_buildCTable(
                  op, (size_t)(oend - op),
                  CTable_MatchLength, MLFSELog, (symbolEncodingType_e)MLtype,
                  count, max, mlCodeTable, nbSeq,
                  ML_defaultNorm, ML_defaultNormLog, MaxML,
                  prevEntropy->fse.matchlengthCTable,
                  sizeof(prevEntropy->fse.matchlengthCTable),
                  entropyWorkspace, entropyWkspSize);
              FORWARD_IF_ERROR(countSize);
              if (MLtype == set_compressed)
                  lastNCount = op;
              op += countSize;
              assert(op <= oend);
      }   }
  
      *seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
  
      {   size_t const bitstreamSize = ZSTD_encodeSequences(
                                          op, (size_t)(oend - op),
                                          CTable_MatchLength, mlCodeTable,
                                          CTable_OffsetBits, ofCodeTable,
                                          CTable_LitLength, llCodeTable,
                                          sequences, nbSeq,
                                          longOffsets, bmi2);
          FORWARD_IF_ERROR(bitstreamSize);
          op += bitstreamSize;
          assert(op <= oend);
          /* zstd versions <= 1.3.4 mistakenly report corruption when
           * FSE_readNCount() receives a buffer < 4 bytes.
           * Fixed by https://github.com/facebook/zstd/pull/1146.
           * This can happen when the last set_compressed table present is 2
           * bytes and the bitstream is only one byte.
           * In this exceedingly rare case, we will simply emit an uncompressed
           * block, since it isn't worth optimizing.
           */
          if (lastNCount && (op - lastNCount) < 4) {
              /* NCountSize >= 2 && bitstreamSize > 0 ==> lastCountSize == 3 */
              assert(op - lastNCount == 3);
              DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.3.4 by "
                          "emitting an uncompressed block.");
              return 0;
          }
      }
  
      DEBUGLOG(5, "compressed block size : %u", (unsigned)(op - ostart));
      return (size_t)(op - ostart);
  }
  
  MEM_STATIC size_t
  ZSTD_compressSequences(seqStore_t* seqStorePtr,
                         const ZSTD_entropyCTables_t* prevEntropy,
                               ZSTD_entropyCTables_t* nextEntropy,
                         const ZSTD_CCtx_params* cctxParams,
                               void* dst, size_t dstCapacity,
                               size_t srcSize,
                               void* entropyWorkspace, size_t entropyWkspSize,
                               int bmi2)
  {
      size_t const cSize = ZSTD_compressSequences_internal(
                              seqStorePtr, prevEntropy, nextEntropy, cctxParams,
                              dst, dstCapacity,
                              entropyWorkspace, entropyWkspSize, bmi2);
      if (cSize == 0) return 0;
      /* When srcSize <= dstCapacity, there is enough space to write a raw uncompressed block.
       * Since we ran out of space, block must be not compressible, so fall back to raw uncompressed block.
       */
      if ((cSize == ERROR(dstSize_tooSmall)) & (srcSize <= dstCapacity))
          return 0;  /* block not compressed */
      FORWARD_IF_ERROR(cSize);
  
      /* Check compressibility */
      {   size_t const maxCSize = srcSize - ZSTD_minGain(srcSize, cctxParams->cParams.strategy);
          if (cSize >= maxCSize) return 0;  /* block not compressed */
      }
  
      return cSize;
  }
  
  /* ZSTD_selectBlockCompressor() :
   * Not static, but internal use only (used by long distance matcher)
   * assumption : strat is a valid strategy */
  ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, ZSTD_dictMode_e dictMode)
  {
      static const ZSTD_blockCompressor blockCompressor[3][ZSTD_STRATEGY_MAX+1] = {
          { ZSTD_compressBlock_fast  /* default for 0 */,
            ZSTD_compressBlock_fast,
            ZSTD_compressBlock_doubleFast,
            ZSTD_compressBlock_greedy,
            ZSTD_compressBlock_lazy,
            ZSTD_compressBlock_lazy2,
            ZSTD_compressBlock_btlazy2,
            ZSTD_compressBlock_btopt,
            ZSTD_compressBlock_btultra,
            ZSTD_compressBlock_btultra2 },
          { ZSTD_compressBlock_fast_extDict  /* default for 0 */,
            ZSTD_compressBlock_fast_extDict,
            ZSTD_compressBlock_doubleFast_extDict,
            ZSTD_compressBlock_greedy_extDict,
            ZSTD_compressBlock_lazy_extDict,
            ZSTD_compressBlock_lazy2_extDict,
            ZSTD_compressBlock_btlazy2_extDict,
            ZSTD_compressBlock_btopt_extDict,
            ZSTD_compressBlock_btultra_extDict,
            ZSTD_compressBlock_btultra_extDict },
          { ZSTD_compressBlock_fast_dictMatchState  /* default for 0 */,
            ZSTD_compressBlock_fast_dictMatchState,
            ZSTD_compressBlock_doubleFast_dictMatchState,
            ZSTD_compressBlock_greedy_dictMatchState,
            ZSTD_compressBlock_lazy_dictMatchState,
            ZSTD_compressBlock_lazy2_dictMatchState,
            ZSTD_compressBlock_btlazy2_dictMatchState,
            ZSTD_compressBlock_btopt_dictMatchState,
            ZSTD_compressBlock_btultra_dictMatchState,
            ZSTD_compressBlock_btultra_dictMatchState }
      };
      ZSTD_blockCompressor selectedCompressor;
      ZSTD_STATIC_ASSERT((unsigned)ZSTD_fast == 1);
  
      assert(ZSTD_cParam_withinBounds(ZSTD_c_strategy, strat));
      selectedCompressor = blockCompressor[(int)dictMode][(int)strat];
      assert(selectedCompressor != NULL);
      return selectedCompressor;
  }
  
  static void ZSTD_storeLastLiterals(seqStore_t* seqStorePtr,
                                     const BYTE* anchor, size_t lastLLSize)
  {
      memcpy(seqStorePtr->lit, anchor, lastLLSize);
      seqStorePtr->lit += lastLLSize;
  }
  
  void ZSTD_resetSeqStore(seqStore_t* ssPtr)
  {
      ssPtr->lit = ssPtr->litStart;
      ssPtr->sequences = ssPtr->sequencesStart;
      ssPtr->longLengthID = 0;
  }
  
  typedef enum { ZSTDbss_compress, ZSTDbss_noCompress } ZSTD_buildSeqStore_e;
  
  static size_t ZSTD_buildSeqStore(ZSTD_CCtx* zc, const void* src, size_t srcSize)
  {
      ZSTD_matchState_t* const ms = &zc->blockState.matchState;
      DEBUGLOG(5, "ZSTD_buildSeqStore (srcSize=%zu)", srcSize);
      assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
      /* Assert that we have correctly flushed the ctx params into the ms's copy */
      ZSTD_assertEqualCParams(zc->appliedParams.cParams, ms->cParams);
      if (srcSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) {
          ZSTD_ldm_skipSequences(&zc->externSeqStore, srcSize, zc->appliedParams.cParams.minMatch);
          return ZSTDbss_noCompress; /* don't even attempt compression below a certain srcSize */
      }
      ZSTD_resetSeqStore(&(zc->seqStore));
      /* required for optimal parser to read stats from dictionary */
      ms->opt.symbolCosts = &zc->blockState.prevCBlock->entropy;
      /* tell the optimal parser how we expect to compress literals */
      ms->opt.literalCompressionMode = zc->appliedParams.literalCompressionMode;
      /* a gap between an attached dict and the current window is not safe,
       * they must remain adjacent,
       * and when that stops being the case, the dict must be unset */
      assert(ms->dictMatchState == NULL || ms->loadedDictEnd == ms->window.dictLimit);
  
      /* limited update after a very long match */
      {   const BYTE* const base = ms->window.base;
          const BYTE* const istart = (const BYTE*)src;
          const U32 current = (U32)(istart-base);
          if (sizeof(ptrdiff_t)==8) assert(istart - base < (ptrdiff_t)(U32)(-1));   /* ensure no overflow */
          if (current > ms->nextToUpdate + 384)
              ms->nextToUpdate = current - MIN(192, (U32)(current - ms->nextToUpdate - 384));
      }
  
      /* select and store sequences */
      {   ZSTD_dictMode_e const dictMode = ZSTD_matchState_dictMode(ms);
          size_t lastLLSize;
          {   int i;
              for (i = 0; i < ZSTD_REP_NUM; ++i)
                  zc->blockState.nextCBlock->rep[i] = zc->blockState.prevCBlock->rep[i];
          }
          if (zc->externSeqStore.pos < zc->externSeqStore.size) {
              assert(!zc->appliedParams.ldmParams.enableLdm);
              /* Updates ldmSeqStore.pos */
              lastLLSize =
                  ZSTD_ldm_blockCompress(&zc->externSeqStore,
                                         ms, &zc->seqStore,
                                         zc->blockState.nextCBlock->rep,
                                         src, srcSize);
              assert(zc->externSeqStore.pos <= zc->externSeqStore.size);
          } else if (zc->appliedParams.ldmParams.enableLdm) {
              rawSeqStore_t ldmSeqStore = {NULL, 0, 0, 0};
  
              ldmSeqStore.seq = zc->ldmSequences;
              ldmSeqStore.capacity = zc->maxNbLdmSequences;
              /* Updates ldmSeqStore.size */
              FORWARD_IF_ERROR(ZSTD_ldm_generateSequences(&zc->ldmState, &ldmSeqStore,
                                                 &zc->appliedParams.ldmParams,
                                                 src, srcSize));
              /* Updates ldmSeqStore.pos */
              lastLLSize =
                  ZSTD_ldm_blockCompress(&ldmSeqStore,
                                         ms, &zc->seqStore,
                                         zc->blockState.nextCBlock->rep,
                                         src, srcSize);
              assert(ldmSeqStore.pos == ldmSeqStore.size);
          } else {   /* not long range mode */
              ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->appliedParams.cParams.strategy, dictMode);
              lastLLSize = blockCompressor(ms, &zc->seqStore, zc->blockState.nextCBlock->rep, src, srcSize);
          }
          {   const BYTE* const lastLiterals = (const BYTE*)src + srcSize - lastLLSize;
              ZSTD_storeLastLiterals(&zc->seqStore, lastLiterals, lastLLSize);
      }   }
      return ZSTDbss_compress;
  }
  
  static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
  {
      const seqStore_t* seqStore = ZSTD_getSeqStore(zc);
      const seqDef* seqs = seqStore->sequencesStart;
      size_t seqsSize = seqStore->sequences - seqs;
  
      ZSTD_Sequence* outSeqs = &zc->seqCollector.seqStart[zc->seqCollector.seqIndex];
      size_t i; size_t position; int repIdx;
  
      assert(zc->seqCollector.seqIndex + 1 < zc->seqCollector.maxSequences);
      for (i = 0, position = 0; i < seqsSize; ++i) {
          outSeqs[i].offset = seqs[i].offset;
          outSeqs[i].litLength = seqs[i].litLength;
          outSeqs[i].matchLength = seqs[i].matchLength + MINMATCH;
  
          if (i == seqStore->longLengthPos) {
              if (seqStore->longLengthID == 1) {
                  outSeqs[i].litLength += 0x10000;
              } else if (seqStore->longLengthID == 2) {
                  outSeqs[i].matchLength += 0x10000;
              }
          }
  
          if (outSeqs[i].offset <= ZSTD_REP_NUM) {
              outSeqs[i].rep = outSeqs[i].offset;
              repIdx = (unsigned int)i - outSeqs[i].offset;
  
              if (outSeqs[i].litLength == 0) {
                  if (outSeqs[i].offset < 3) {
                      --repIdx;
                  } else {
                      repIdx = (unsigned int)i - 1;
                  }
                  ++outSeqs[i].rep;
              }
              assert(repIdx >= -3);
              outSeqs[i].offset = repIdx >= 0 ? outSeqs[repIdx].offset : repStartValue[-repIdx - 1];
              if (outSeqs[i].rep == 4) {
                  --outSeqs[i].offset;
              }
          } else {
              outSeqs[i].offset -= ZSTD_REP_NUM;
          }
  
          position += outSeqs[i].litLength;
          outSeqs[i].matchPos = (unsigned int)position;
          position += outSeqs[i].matchLength;
      }
      zc->seqCollector.seqIndex += seqsSize;
  }
  
  size_t ZSTD_getSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
      size_t outSeqsSize, const void* src, size_t srcSize)
  {
      const size_t dstCapacity = ZSTD_compressBound(srcSize);
      void* dst = ZSTD_malloc(dstCapacity, ZSTD_defaultCMem);
      SeqCollector seqCollector;
  
      RETURN_ERROR_IF(dst == NULL, memory_allocation);
  
      seqCollector.collectSequences = 1;
      seqCollector.seqStart = outSeqs;
      seqCollector.seqIndex = 0;
      seqCollector.maxSequences = outSeqsSize;
      zc->seqCollector = seqCollector;
  
      ZSTD_compress2(zc, dst, dstCapacity, src, srcSize);
      ZSTD_free(dst, ZSTD_defaultCMem);
      return zc->seqCollector.seqIndex;
  }
  
  /* Returns true if the given block is a RLE block */
  static int ZSTD_isRLE(const BYTE *ip, size_t length) {
      size_t i;
      if (length < 2) return 1;
      for (i = 1; i < length; ++i) {
          if (ip[0] != ip[i]) return 0;
      }
      return 1;
  }
  
  static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
                                          void* dst, size_t dstCapacity,
                                          const void* src, size_t srcSize, U32 frame)
  {
      /* This the upper bound for the length of an rle block.
       * This isn't the actual upper bound. Finding the real threshold
       * needs further investigation.
       */
      const U32 rleMaxLength = 25;
      size_t cSize;
      const BYTE* ip = (const BYTE*)src;
      BYTE* op = (BYTE*)dst;
      DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
                  (unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit,
                  (unsigned)zc->blockState.matchState.nextToUpdate);
  
      {   const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
          FORWARD_IF_ERROR(bss);
          if (bss == ZSTDbss_noCompress) { cSize = 0; goto out; }
      }
  
      if (zc->seqCollector.collectSequences) {
          ZSTD_copyBlockSequences(zc);
          return 0;
      }
  
      /* encode sequences and literals */
      cSize = ZSTD_compressSequences(&zc->seqStore,
              &zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
              &zc->appliedParams,
              dst, dstCapacity,
              srcSize,
              zc->entropyWorkspace, HUF_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
              zc->bmi2);
  
      if (frame &&
          /* We don't want to emit our first block as a RLE even if it qualifies because
           * doing so will cause the decoder (cli only) to throw a "should consume all input error."
           * This is only an issue for zstd <= v1.4.3
           */
          !zc->isFirstBlock &&
          cSize < rleMaxLength &&
          ZSTD_isRLE(ip, srcSize))
      {
          cSize = 1;
          op[0] = ip[0];
      }
  
  out:
      if (!ZSTD_isError(cSize) && cSize > 1) {
          /* confirm repcodes and entropy tables when emitting a compressed block */
          ZSTD_compressedBlockState_t* const tmp = zc->blockState.prevCBlock;
          zc->blockState.prevCBlock = zc->blockState.nextCBlock;
          zc->blockState.nextCBlock = tmp;
      }
      /* We check that dictionaries have offset codes available for the first
       * block. After the first block, the offcode table might not have large
       * enough codes to represent the offsets in the data.
       */
      if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
          zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
  
      return cSize;
  }
  
  
  static void ZSTD_overflowCorrectIfNeeded(ZSTD_matchState_t* ms,
                                           ZSTD_cwksp* ws,
                                           ZSTD_CCtx_params const* params,
                                           void const* ip,
                                           void const* iend)
  {
      if (ZSTD_window_needOverflowCorrection(ms->window, iend)) {
          U32 const maxDist = (U32)1 << params->cParams.windowLog;
          U32 const cycleLog = ZSTD_cycleLog(params->cParams.chainLog, params->cParams.strategy);
          U32 const correction = ZSTD_window_correctOverflow(&ms->window, cycleLog, maxDist, ip);
          ZSTD_STATIC_ASSERT(ZSTD_CHAINLOG_MAX <= 30);
          ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX_32 <= 30);
          ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31);
          ZSTD_cwksp_mark_tables_dirty(ws);
          ZSTD_reduceIndex(ms, params, correction);
          ZSTD_cwksp_mark_tables_clean(ws);
          if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
          else ms->nextToUpdate -= correction;
          /* invalidate dictionaries on overflow correction */
          ms->loadedDictEnd = 0;
          ms->dictMatchState = NULL;
      }
  }
  
  /*! ZSTD_compress_frameChunk() :
  *   Compress a chunk of data into one or multiple blocks.
  *   All blocks will be terminated, all input will be consumed.
  *   Function will issue an error if there is not enough `dstCapacity` to hold the compressed content.
  *   Frame is supposed already started (header already produced)
  *   @return : compressed size, or an error code
  */
  static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
                                       void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize,
                                       U32 lastFrameChunk)
  {
      size_t blockSize = cctx->blockSize;
      size_t remaining = srcSize;
      const BYTE* ip = (const BYTE*)src;
      BYTE* const ostart = (BYTE*)dst;
      BYTE* op = ostart;
      U32 const maxDist = (U32)1 << cctx->appliedParams.cParams.windowLog;
      assert(cctx->appliedParams.cParams.windowLog <= ZSTD_WINDOWLOG_MAX);
  
      DEBUGLOG(5, "ZSTD_compress_frameChunk (blockSize=%u)", (unsigned)blockSize);
      if (cctx->appliedParams.fParams.checksumFlag && srcSize)
          XXH64_update(&cctx->xxhState, src, srcSize);
  
      while (remaining) {
          ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
          U32 const lastBlock = lastFrameChunk & (blockSize >= remaining);
  
          RETURN_ERROR_IF(dstCapacity < ZSTD_blockHeaderSize + MIN_CBLOCK_SIZE,
                          dstSize_tooSmall,
                          "not enough space to store compressed block");
          if (remaining < blockSize) blockSize = remaining;
  
          ZSTD_overflowCorrectIfNeeded(
              ms, &cctx->workspace, &cctx->appliedParams, ip, ip + blockSize);
          ZSTD_checkDictValidity(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd, &ms->dictMatchState);
  
          /* Ensure hash/chain table insertion resumes no sooner than lowlimit */
          if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
  
          {   size_t cSize = ZSTD_compressBlock_internal(cctx,
                                  op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize,
                                  ip, blockSize, 1 /* frame */);
              FORWARD_IF_ERROR(cSize);
              if (cSize == 0) {  /* block is not compressible */
                  cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
                  FORWARD_IF_ERROR(cSize);
              } else {
                  const U32 cBlockHeader = cSize == 1 ?
                      lastBlock + (((U32)bt_rle)<<1) + (U32)(blockSize << 3) :
                      lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
                  MEM_writeLE24(op, cBlockHeader);
                  cSize += ZSTD_blockHeaderSize;
              }
  
              ip += blockSize;
              assert(remaining >= blockSize);
              remaining -= blockSize;
              op += cSize;
              assert(dstCapacity >= cSize);
              dstCapacity -= cSize;
              cctx->isFirstBlock = 0;
              DEBUGLOG(5, "ZSTD_compress_frameChunk: adding a block of size %u",
                          (unsigned)cSize);
      }   }
  
      if (lastFrameChunk && (op>ostart)) cctx->stage = ZSTDcs_ending;
      return (size_t)(op-ostart);
  }
  
  
  static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
                                      const ZSTD_CCtx_params* params, U64 pledgedSrcSize, U32 dictID)
  {   BYTE* const op = (BYTE*)dst;
      U32   const dictIDSizeCodeLength = (dictID>0) + (dictID>=256) + (dictID>=65536);   /* 0-3 */
      U32   const dictIDSizeCode = params->fParams.noDictIDFlag ? 0 : dictIDSizeCodeLength;   /* 0-3 */
      U32   const checksumFlag = params->fParams.checksumFlag>0;
      U32   const windowSize = (U32)1 << params->cParams.windowLog;
      U32   const singleSegment = params->fParams.contentSizeFlag && (windowSize >= pledgedSrcSize);
      BYTE  const windowLogByte = (BYTE)((params->cParams.windowLog - ZSTD_WINDOWLOG_ABSOLUTEMIN) << 3);
      U32   const fcsCode = params->fParams.contentSizeFlag ?
                       (pledgedSrcSize>=256) + (pledgedSrcSize>=65536+256) + (pledgedSrcSize>=0xFFFFFFFFU) : 0;  /* 0-3 */
      BYTE  const frameHeaderDescriptionByte = (BYTE)(dictIDSizeCode + (checksumFlag<<2) + (singleSegment<<5) + (fcsCode<<6) );
      size_t pos=0;
  
      assert(!(params->fParams.contentSizeFlag && pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN));
      RETURN_ERROR_IF(dstCapacity < ZSTD_FRAMEHEADERSIZE_MAX, dstSize_tooSmall);
      DEBUGLOG(4, "ZSTD_writeFrameHeader : dictIDFlag : %u ; dictID : %u ; dictIDSizeCode : %u",
                  !params->fParams.noDictIDFlag, (unsigned)dictID, (unsigned)dictIDSizeCode);
  
      if (params->format == ZSTD_f_zstd1) {
          MEM_writeLE32(dst, ZSTD_MAGICNUMBER);
          pos = 4;
      }
      op[pos++] = frameHeaderDescriptionByte;
      if (!singleSegment) op[pos++] = windowLogByte;
      switch(dictIDSizeCode)
      {
          default:  assert(0); /* impossible */
          case 0 : break;
          case 1 : op[pos] = (BYTE)(dictID); pos++; break;
          case 2 : MEM_writeLE16(op+pos, (U16)dictID); pos+=2; break;
          case 3 : MEM_writeLE32(op+pos, dictID); pos+=4; break;
      }
      switch(fcsCode)
      {
          default:  assert(0); /* impossible */
          case 0 : if (singleSegment) op[pos++] = (BYTE)(pledgedSrcSize); break;
          case 1 : MEM_writeLE16(op+pos, (U16)(pledgedSrcSize-256)); pos+=2; break;
          case 2 : MEM_writeLE32(op+pos, (U32)(pledgedSrcSize)); pos+=4; break;
          case 3 : MEM_writeLE64(op+pos, (U64)(pledgedSrcSize)); pos+=8; break;
      }
      return pos;
  }
  
  /* ZSTD_writeLastEmptyBlock() :
   * output an empty Block with end-of-frame mark to complete a frame
   * @return : size of data written into `dst` (== ZSTD_blockHeaderSize (defined in zstd_internal.h))
   *           or an error code if `dstCapacity` is too small (<ZSTD_blockHeaderSize)
   */
  size_t ZSTD_writeLastEmptyBlock(void* dst, size_t dstCapacity)
  {
      RETURN_ERROR_IF(dstCapacity < ZSTD_blockHeaderSize, dstSize_tooSmall);
      {   U32 const cBlockHeader24 = 1 /*lastBlock*/ + (((U32)bt_raw)<<1);  /* 0 size */
          MEM_writeLE24(dst, cBlockHeader24);
          return ZSTD_blockHeaderSize;
      }
  }
  
  size_t ZSTD_referenceExternalSequences(ZSTD_CCtx* cctx, rawSeq* seq, size_t nbSeq)
  {
      RETURN_ERROR_IF(cctx->stage != ZSTDcs_init, stage_wrong);
      RETURN_ERROR_IF(cctx->appliedParams.ldmParams.enableLdm,
                      parameter_unsupported);
      cctx->externSeqStore.seq = seq;
      cctx->externSeqStore.size = nbSeq;
      cctx->externSeqStore.capacity = nbSeq;
      cctx->externSeqStore.pos = 0;
      return 0;
  }
  
  
  static size_t ZSTD_compressContinue_internal (ZSTD_CCtx* cctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                                 U32 frame, U32 lastFrameChunk)
  {
      ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
      size_t fhSize = 0;
  
      DEBUGLOG(5, "ZSTD_compressContinue_internal, stage: %u, srcSize: %u",
                  cctx->stage, (unsigned)srcSize);
      RETURN_ERROR_IF(cctx->stage==ZSTDcs_created, stage_wrong,
                      "missing init (ZSTD_compressBegin)");
  
      if (frame && (cctx->stage==ZSTDcs_init)) {
          fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, &cctx->appliedParams,
                                         cctx->pledgedSrcSizePlusOne-1, cctx->dictID);
          FORWARD_IF_ERROR(fhSize);
          assert(fhSize <= dstCapacity);
          dstCapacity -= fhSize;
          dst = (char*)dst + fhSize;
          cctx->stage = ZSTDcs_ongoing;
      }
  
      if (!srcSize) return fhSize;  /* do not generate an empty block if no input */
  
      if (!ZSTD_window_update(&ms->window, src, srcSize)) {
          ms->nextToUpdate = ms->window.dictLimit;
      }
      if (cctx->appliedParams.ldmParams.enableLdm) {
          ZSTD_window_update(&cctx->ldmState.window, src, srcSize);
      }
  
      if (!frame) {
          /* overflow check and correction for block mode */
          ZSTD_overflowCorrectIfNeeded(
              ms, &cctx->workspace, &cctx->appliedParams,
              src, (BYTE const*)src + srcSize);
      }
  
      DEBUGLOG(5, "ZSTD_compressContinue_internal (blockSize=%u)", (unsigned)cctx->blockSize);
      {   size_t const cSize = frame ?
                               ZSTD_compress_frameChunk (cctx, dst, dstCapacity, src, srcSize, lastFrameChunk) :
                               ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize, 0 /* frame */);
          FORWARD_IF_ERROR(cSize);
          cctx->consumedSrcSize += srcSize;
          cctx->producedCSize += (cSize + fhSize);
          assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
          if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
              ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
              RETURN_ERROR_IF(
                  cctx->consumedSrcSize+1 > cctx->pledgedSrcSizePlusOne,
                  srcSize_wrong,
                  "error : pledgedSrcSize = %u, while realSrcSize >= %u",
                  (unsigned)cctx->pledgedSrcSizePlusOne-1,
                  (unsigned)cctx->consumedSrcSize);
          }
          return cSize + fhSize;
      }
  }
  
  size_t ZSTD_compressContinue (ZSTD_CCtx* cctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize)
  {
      DEBUGLOG(5, "ZSTD_compressContinue (srcSize=%u)", (unsigned)srcSize);
      return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1 /* frame mode */, 0 /* last chunk */);
  }
  
  
  size_t ZSTD_getBlockSize(const ZSTD_CCtx* cctx)
  {
      ZSTD_compressionParameters const cParams = cctx->appliedParams.cParams;
      assert(!ZSTD_checkCParams(cParams));
      return MIN (ZSTD_BLOCKSIZE_MAX, (U32)1 << cParams.windowLog);
  }
  
  size_t ZSTD_compressBlock(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
  {
      DEBUGLOG(5, "ZSTD_compressBlock: srcSize = %u", (unsigned)srcSize);
      { size_t const blockSizeMax = ZSTD_getBlockSize(cctx);
        RETURN_ERROR_IF(srcSize > blockSizeMax, srcSize_wrong); }
  
      return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 0 /* frame mode */, 0 /* last chunk */);
  }
  
  /*! ZSTD_loadDictionaryContent() :
   *  @return : 0, or an error code
   */
  static size_t ZSTD_loadDictionaryContent(ZSTD_matchState_t* ms,
                                           ZSTD_cwksp* ws,
                                           ZSTD_CCtx_params const* params,
                                           const void* src, size_t srcSize,
                                           ZSTD_dictTableLoadMethod_e dtlm)
  {
      const BYTE* ip = (const BYTE*) src;
      const BYTE* const iend = ip + srcSize;
  
      ZSTD_window_update(&ms->window, src, srcSize);
      ms->loadedDictEnd = params->forceWindow ? 0 : (U32)(iend - ms->window.base);
  
      /* Assert that we the ms params match the params we're being given */
      ZSTD_assertEqualCParams(params->cParams, ms->cParams);
  
      if (srcSize <= HASH_READ_SIZE) return 0;
  
      while (iend - ip > HASH_READ_SIZE) {
          size_t const remaining = (size_t)(iend - ip);
          size_t const chunk = MIN(remaining, ZSTD_CHUNKSIZE_MAX);
          const BYTE* const ichunk = ip + chunk;
  
          ZSTD_overflowCorrectIfNeeded(ms, ws, params, ip, ichunk);
  
          switch(params->cParams.strategy)
          {
          case ZSTD_fast:
              ZSTD_fillHashTable(ms, ichunk, dtlm);
              break;
          case ZSTD_dfast:
              ZSTD_fillDoubleHashTable(ms, ichunk, dtlm);
              break;
  
          case ZSTD_greedy:
          case ZSTD_lazy:
          case ZSTD_lazy2:
              if (chunk >= HASH_READ_SIZE)
                  ZSTD_insertAndFindFirstIndex(ms, ichunk-HASH_READ_SIZE);
              break;
  
          case ZSTD_btlazy2:   /* we want the dictionary table fully sorted */
          case ZSTD_btopt:
          case ZSTD_btultra:
          case ZSTD_btultra2:
              if (chunk >= HASH_READ_SIZE)
                  ZSTD_updateTree(ms, ichunk-HASH_READ_SIZE, ichunk);
              break;
  
          default:
              assert(0);  /* not possible : not a valid strategy id */
          }
  
          ip = ichunk;
      }
  
      ms->nextToUpdate = (U32)(iend - ms->window.base);
      return 0;
  }
  
  
  /* Dictionaries that assign zero probability to symbols that show up causes problems
     when FSE encoding.  Refuse dictionaries that assign zero probability to symbols
     that we may encounter during compression.
     NOTE: This behavior is not standard and could be improved in the future. */
  static size_t ZSTD_checkDictNCount(short* normalizedCounter, unsigned dictMaxSymbolValue, unsigned maxSymbolValue) {
      U32 s;
      RETURN_ERROR_IF(dictMaxSymbolValue < maxSymbolValue, dictionary_corrupted);
      for (s = 0; s <= maxSymbolValue; ++s) {
          RETURN_ERROR_IF(normalizedCounter[s] == 0, dictionary_corrupted);
      }
      return 0;
  }
  
  
  /* Dictionary format :
   * See :
   * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
   */
  /*! ZSTD_loadZstdDictionary() :
   * @return : dictID, or an error code
   *  assumptions : magic number supposed already checked
   *                dictSize supposed >= 8
   */
  static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
                                        ZSTD_matchState_t* ms,
                                        ZSTD_cwksp* ws,
                                        ZSTD_CCtx_params const* params,
                                        const void* dict, size_t dictSize,
                                        ZSTD_dictTableLoadMethod_e dtlm,
                                        void* workspace)
  {
      const BYTE* dictPtr = (const BYTE*)dict;
      const BYTE* const dictEnd = dictPtr + dictSize;
      short offcodeNCount[MaxOff+1];
      unsigned offcodeMaxValue = MaxOff;
      size_t dictID;
  
      ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<<MAX(MLFSELog,LLFSELog)));
      assert(dictSize >= 8);
      assert(MEM_readLE32(dictPtr) == ZSTD_MAGIC_DICTIONARY);
  
      dictPtr += 4;   /* skip magic number */
      dictID = params->fParams.noDictIDFlag ? 0 :  MEM_readLE32(dictPtr);
      dictPtr += 4;
  
      {   unsigned maxSymbolValue = 255;
          size_t const hufHeaderSize = HUF_readCTable((HUF_CElt*)bs->entropy.huf.CTable, &maxSymbolValue, dictPtr, dictEnd-dictPtr);
          RETURN_ERROR_IF(HUF_isError(hufHeaderSize), dictionary_corrupted);
          RETURN_ERROR_IF(maxSymbolValue < 255, dictionary_corrupted);
          dictPtr += hufHeaderSize;
      }
  
      {   unsigned offcodeLog;
          size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
          RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted);
          RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted);
          /* Defer checking offcodeMaxValue because we need to know the size of the dictionary content */
          /* fill all offset symbols to avoid garbage at end of table */
          RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
                  bs->entropy.fse.offcodeCTable,
                  offcodeNCount, MaxOff, offcodeLog,
                  workspace, HUF_WORKSPACE_SIZE)),
              dictionary_corrupted);
          dictPtr += offcodeHeaderSize;
      }
  
      {   short matchlengthNCount[MaxML+1];
          unsigned matchlengthMaxValue = MaxML, matchlengthLog;
          size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
          RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted);
          RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted);
          /* Every match length code must have non-zero probability */
          FORWARD_IF_ERROR( ZSTD_checkDictNCount(matchlengthNCount, matchlengthMaxValue, MaxML));
          RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
                  bs->entropy.fse.matchlengthCTable,
                  matchlengthNCount, matchlengthMaxValue, matchlengthLog,
                  workspace, HUF_WORKSPACE_SIZE)),
              dictionary_corrupted);
          dictPtr += matchlengthHeaderSize;
      }
  
      {   short litlengthNCount[MaxLL+1];
          unsigned litlengthMaxValue = MaxLL, litlengthLog;
          size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
          RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted);
          RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted);
          /* Every literal length code must have non-zero probability */
          FORWARD_IF_ERROR( ZSTD_checkDictNCount(litlengthNCount, litlengthMaxValue, MaxLL));
          RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
                  bs->entropy.fse.litlengthCTable,
                  litlengthNCount, litlengthMaxValue, litlengthLog,
                  workspace, HUF_WORKSPACE_SIZE)),
              dictionary_corrupted);
          dictPtr += litlengthHeaderSize;
      }
  
      RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted);
      bs->rep[0] = MEM_readLE32(dictPtr+0);
      bs->rep[1] = MEM_readLE32(dictPtr+4);
      bs->rep[2] = MEM_readLE32(dictPtr+8);
      dictPtr += 12;
  
      {   size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
          U32 offcodeMax = MaxOff;
          if (dictContentSize <= ((U32)-1) - 128 KB) {
              U32 const maxOffset = (U32)dictContentSize + 128 KB; /* The maximum offset that must be supported */
              offcodeMax = ZSTD_highbit32(maxOffset); /* Calculate minimum offset code required to represent maxOffset */
          }
          /* All offset values <= dictContentSize + 128 KB must be representable */
          FORWARD_IF_ERROR(ZSTD_checkDictNCount(offcodeNCount, offcodeMaxValue, MIN(offcodeMax, MaxOff)));
          /* All repCodes must be <= dictContentSize and != 0*/
          {   U32 u;
              for (u=0; u<3; u++) {
                  RETURN_ERROR_IF(bs->rep[u] == 0, dictionary_corrupted);
                  RETURN_ERROR_IF(bs->rep[u] > dictContentSize, dictionary_corrupted);
          }   }
  
          bs->entropy.huf.repeatMode = HUF_repeat_valid;
          bs->entropy.fse.offcode_repeatMode = FSE_repeat_valid;
          bs->entropy.fse.matchlength_repeatMode = FSE_repeat_valid;
          bs->entropy.fse.litlength_repeatMode = FSE_repeat_valid;
          FORWARD_IF_ERROR(ZSTD_loadDictionaryContent(
              ms, ws, params, dictPtr, dictContentSize, dtlm));
          return dictID;
      }
  }
  
  /** ZSTD_compress_insertDictionary() :
  *   @return : dictID, or an error code */
  static size_t
  ZSTD_compress_insertDictionary(ZSTD_compressedBlockState_t* bs,
                                 ZSTD_matchState_t* ms,
                                 ZSTD_cwksp* ws,
                           const ZSTD_CCtx_params* params,
                           const void* dict, size_t dictSize,
                                 ZSTD_dictContentType_e dictContentType,
                                 ZSTD_dictTableLoadMethod_e dtlm,
                                 void* workspace)
  {
      DEBUGLOG(4, "ZSTD_compress_insertDictionary (dictSize=%u)", (U32)dictSize);
      if ((dict==NULL) || (dictSize<8)) {
          RETURN_ERROR_IF(dictContentType == ZSTD_dct_fullDict, dictionary_wrong);
          return 0;
      }
  
      ZSTD_reset_compressedBlockState(bs);
  
      /* dict restricted modes */
      if (dictContentType == ZSTD_dct_rawContent)
          return ZSTD_loadDictionaryContent(ms, ws, params, dict, dictSize, dtlm);
  
      if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) {
          if (dictContentType == ZSTD_dct_auto) {
              DEBUGLOG(4, "raw content dictionary detected");
              return ZSTD_loadDictionaryContent(
                  ms, ws, params, dict, dictSize, dtlm);
          }
          RETURN_ERROR_IF(dictContentType == ZSTD_dct_fullDict, dictionary_wrong);
          assert(0);   /* impossible */
      }
  
      /* dict as full zstd dictionary */
      return ZSTD_loadZstdDictionary(
          bs, ms, ws, params, dict, dictSize, dtlm, workspace);
  }
  
  #define ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF (128 KB)
  #define ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER (6)
  
  /*! ZSTD_compressBegin_internal() :
   * @return : 0, or an error code */
  static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
                                      const void* dict, size_t dictSize,
                                      ZSTD_dictContentType_e dictContentType,
                                      ZSTD_dictTableLoadMethod_e dtlm,
                                      const ZSTD_CDict* cdict,
                                      const ZSTD_CCtx_params* params, U64 pledgedSrcSize,
                                      ZSTD_buffered_policy_e zbuff)
  {
      DEBUGLOG(4, "ZSTD_compressBegin_internal: wlog=%u", params->cParams.windowLog);
      /* params are supposed to be fully validated at this point */
      assert(!ZSTD_isError(ZSTD_checkCParams(params->cParams)));
      assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
      if ( (cdict)
        && (cdict->dictContentSize > 0)
        && ( pledgedSrcSize < ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF
          || pledgedSrcSize < cdict->dictContentSize * ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER
          || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
          || cdict->compressionLevel == 0)
        && (params->attachDictPref != ZSTD_dictForceLoad) ) {
          return ZSTD_resetCCtx_usingCDict(cctx, cdict, params, pledgedSrcSize, zbuff);
      }
  
      FORWARD_IF_ERROR( ZSTD_resetCCtx_internal(cctx, *params, pledgedSrcSize,
                                       ZSTDcrp_makeClean, zbuff) );
      {   size_t const dictID = cdict ?
                  ZSTD_compress_insertDictionary(
                          cctx->blockState.prevCBlock, &cctx->blockState.matchState,
                          &cctx->workspace, params, cdict->dictContent, cdict->dictContentSize,
                          dictContentType, dtlm, cctx->entropyWorkspace)
                : ZSTD_compress_insertDictionary(
                          cctx->blockState.prevCBlock, &cctx->blockState.matchState,
                          &cctx->workspace, params, dict, dictSize,
                          dictContentType, dtlm, cctx->entropyWorkspace);
          FORWARD_IF_ERROR(dictID);
          assert(dictID <= UINT_MAX);
          cctx->dictID = (U32)dictID;
      }
      return 0;
  }
  
  size_t ZSTD_compressBegin_advanced_internal(ZSTD_CCtx* cctx,
                                      const void* dict, size_t dictSize,
                                      ZSTD_dictContentType_e dictContentType,
                                      ZSTD_dictTableLoadMethod_e dtlm,
                                      const ZSTD_CDict* cdict,
                                      const ZSTD_CCtx_params* params,
                                      unsigned long long pledgedSrcSize)
  {
      DEBUGLOG(4, "ZSTD_compressBegin_advanced_internal: wlog=%u", params->cParams.windowLog);
      /* compression parameters verification and optimization */
      FORWARD_IF_ERROR( ZSTD_checkCParams(params->cParams) );
      return ZSTD_compressBegin_internal(cctx,
                                         dict, dictSize, dictContentType, dtlm,
                                         cdict,
                                         params, pledgedSrcSize,
                                         ZSTDb_not_buffered);
  }
  
  /*! ZSTD_compressBegin_advanced() :
  *   @return : 0, or an error code */
  size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx,
                               const void* dict, size_t dictSize,
                                     ZSTD_parameters params, unsigned long long pledgedSrcSize)
  {
      ZSTD_CCtx_params const cctxParams =
              ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
      return ZSTD_compressBegin_advanced_internal(cctx,
                                              dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast,
                                              NULL /*cdict*/,
                                              &cctxParams, pledgedSrcSize);
  }
  
  size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel)
  {
      ZSTD_parameters const params = ZSTD_getParams(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize);
      ZSTD_CCtx_params const cctxParams =
              ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
      DEBUGLOG(4, "ZSTD_compressBegin_usingDict (dictSize=%u)", (unsigned)dictSize);
      return ZSTD_compressBegin_internal(cctx, dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
                                         &cctxParams, ZSTD_CONTENTSIZE_UNKNOWN, ZSTDb_not_buffered);
  }
  
  size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel)
  {
      return ZSTD_compressBegin_usingDict(cctx, NULL, 0, compressionLevel);
  }
  
  
  /*! ZSTD_writeEpilogue() :
  *   Ends a frame.
  *   @return : nb of bytes written into dst (or an error code) */
  static size_t ZSTD_writeEpilogue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity)
  {
      BYTE* const ostart = (BYTE*)dst;
      BYTE* op = ostart;
      size_t fhSize = 0;
  
      DEBUGLOG(4, "ZSTD_writeEpilogue");
      RETURN_ERROR_IF(cctx->stage == ZSTDcs_created, stage_wrong, "init missing");
  
      /* special case : empty frame */
      if (cctx->stage == ZSTDcs_init) {
          fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, &cctx->appliedParams, 0, 0);
          FORWARD_IF_ERROR(fhSize);
          dstCapacity -= fhSize;
          op += fhSize;
          cctx->stage = ZSTDcs_ongoing;
      }
  
      if (cctx->stage != ZSTDcs_ending) {
          /* write one last empty block, make it the "last" block */
          U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1) + 0;
          RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall);
          MEM_writeLE32(op, cBlockHeader24);
          op += ZSTD_blockHeaderSize;
          dstCapacity -= ZSTD_blockHeaderSize;
      }
  
      if (cctx->appliedParams.fParams.checksumFlag) {
          U32 const checksum = (U32) XXH64_digest(&cctx->xxhState);
          RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall);
          DEBUGLOG(4, "ZSTD_writeEpilogue: write checksum : %08X", (unsigned)checksum);
          MEM_writeLE32(op, checksum);
          op += 4;
      }
  
      cctx->stage = ZSTDcs_created;  /* return to "created but no init" status */
      return op-ostart;
  }
  
  size_t ZSTD_compressEnd (ZSTD_CCtx* cctx,
                           void* dst, size_t dstCapacity,
                     const void* src, size_t srcSize)
  {
      size_t endResult;
      size_t const cSize = ZSTD_compressContinue_internal(cctx,
                                  dst, dstCapacity, src, srcSize,
                                  1 /* frame mode */, 1 /* last chunk */);
      FORWARD_IF_ERROR(cSize);
      endResult = ZSTD_writeEpilogue(cctx, (char*)dst + cSize, dstCapacity-cSize);
      FORWARD_IF_ERROR(endResult);
      assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
      if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
          ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
          DEBUGLOG(4, "end of frame : controlling src size");
          RETURN_ERROR_IF(
              cctx->pledgedSrcSizePlusOne != cctx->consumedSrcSize+1,
              srcSize_wrong,
               "error : pledgedSrcSize = %u, while realSrcSize = %u",
              (unsigned)cctx->pledgedSrcSizePlusOne-1,
              (unsigned)cctx->consumedSrcSize);
      }
      return cSize + endResult;
  }
  
  
  static size_t ZSTD_compress_internal (ZSTD_CCtx* cctx,
                                        void* dst, size_t dstCapacity,
                                  const void* src, size_t srcSize,
                                  const void* dict,size_t dictSize,
                                        ZSTD_parameters params)
  {
      ZSTD_CCtx_params const cctxParams =
              ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
      DEBUGLOG(4, "ZSTD_compress_internal");
      return ZSTD_compress_advanced_internal(cctx,
                                             dst, dstCapacity,
                                             src, srcSize,
                                             dict, dictSize,
                                             &cctxParams);
  }
  
  size_t ZSTD_compress_advanced (ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize,
                           const void* dict,size_t dictSize,
                                 ZSTD_parameters params)
  {
      DEBUGLOG(4, "ZSTD_compress_advanced");
      FORWARD_IF_ERROR(ZSTD_checkCParams(params.cParams));
      return ZSTD_compress_internal(cctx,
                                    dst, dstCapacity,
                                    src, srcSize,
                                    dict, dictSize,
                                    params);
  }
  
  /* Internal */
  size_t ZSTD_compress_advanced_internal(
          ZSTD_CCtx* cctx,
          void* dst, size_t dstCapacity,
          const void* src, size_t srcSize,
          const void* dict,size_t dictSize,
          const ZSTD_CCtx_params* params)
  {
      DEBUGLOG(4, "ZSTD_compress_advanced_internal (srcSize:%u)", (unsigned)srcSize);
      FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
                           dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
                           params, srcSize, ZSTDb_not_buffered) );
      return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
  }
  
  size_t ZSTD_compress_usingDict(ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize,
                           const void* dict, size_t dictSize,
                                 int compressionLevel)
  {
      ZSTD_parameters const params = ZSTD_getParams(compressionLevel, srcSize + (!srcSize), dict ? dictSize : 0);
      ZSTD_CCtx_params cctxParams = ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
      assert(params.fParams.contentSizeFlag == 1);
      return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, dict, dictSize, &cctxParams);
  }
  
  size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
                           void* dst, size_t dstCapacity,
                     const void* src, size_t srcSize,
                           int compressionLevel)
  {
      DEBUGLOG(4, "ZSTD_compressCCtx (srcSize=%u)", (unsigned)srcSize);
      assert(cctx != NULL);
      return ZSTD_compress_usingDict(cctx, dst, dstCapacity, src, srcSize, NULL, 0, compressionLevel);
  }
  
  size_t ZSTD_compress(void* dst, size_t dstCapacity,
                 const void* src, size_t srcSize,
                       int compressionLevel)
  {
      size_t result;
      ZSTD_CCtx ctxBody;
      ZSTD_initCCtx(&ctxBody, ZSTD_defaultCMem);
      result = ZSTD_compressCCtx(&ctxBody, dst, dstCapacity, src, srcSize, compressionLevel);
      ZSTD_freeCCtxContent(&ctxBody);   /* can't free ctxBody itself, as it's on stack; free only heap content */
      return result;
  }
  
  
  /* =====  Dictionary API  ===== */
  
  /*! ZSTD_estimateCDictSize_advanced() :
   *  Estimate amount of memory that will be needed to create a dictionary with following arguments */
  size_t ZSTD_estimateCDictSize_advanced(
          size_t dictSize, ZSTD_compressionParameters cParams,
          ZSTD_dictLoadMethod_e dictLoadMethod)
  {
      DEBUGLOG(5, "sizeof(ZSTD_CDict) : %u", (unsigned)sizeof(ZSTD_CDict));
      return ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict))
           + ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE)
           + ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0)
           + (dictLoadMethod == ZSTD_dlm_byRef ? 0
              : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void *))));
  }
  
  size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel)
  {
      ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
      return ZSTD_estimateCDictSize_advanced(dictSize, cParams, ZSTD_dlm_byCopy);
  }
  
  size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict)
  {
      if (cdict==NULL) return 0;   /* support sizeof on NULL */
      DEBUGLOG(5, "sizeof(*cdict) : %u", (unsigned)sizeof(*cdict));
      /* cdict may be in the workspace */
      return (cdict->workspace.workspace == cdict ? 0 : sizeof(*cdict))
          + ZSTD_cwksp_sizeof(&cdict->workspace);
  }
  
  static size_t ZSTD_initCDict_internal(
                      ZSTD_CDict* cdict,
                const void* dictBuffer, size_t dictSize,
                      ZSTD_dictLoadMethod_e dictLoadMethod,
                      ZSTD_dictContentType_e dictContentType,
                      ZSTD_compressionParameters cParams)
  {
      DEBUGLOG(3, "ZSTD_initCDict_internal (dictContentType:%u)", (unsigned)dictContentType);
      assert(!ZSTD_checkCParams(cParams));
      cdict->matchState.cParams = cParams;
      if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dictBuffer) || (!dictSize)) {
          cdict->dictContent = dictBuffer;
      } else {
           void *internalBuffer = ZSTD_cwksp_reserve_object(&cdict->workspace, ZSTD_cwksp_align(dictSize, sizeof(void*)));
          RETURN_ERROR_IF(!internalBuffer, memory_allocation);
          cdict->dictContent = internalBuffer;
          memcpy(internalBuffer, dictBuffer, dictSize);
      }
      cdict->dictContentSize = dictSize;
  
      cdict->entropyWorkspace = (U32*)ZSTD_cwksp_reserve_object(&cdict->workspace, HUF_WORKSPACE_SIZE);
  
  
      /* Reset the state to no dictionary */
      ZSTD_reset_compressedBlockState(&cdict->cBlockState);
      FORWARD_IF_ERROR(ZSTD_reset_matchState(
          &cdict->matchState,
          &cdict->workspace,
          &cParams,
          ZSTDcrp_makeClean,
          ZSTDirp_reset,
          ZSTD_resetTarget_CDict));
      /* (Maybe) load the dictionary
       * Skips loading the dictionary if it is < 8 bytes.
       */
      {   ZSTD_CCtx_params params;
          memset(&params, 0, sizeof(params));
          params.compressionLevel = ZSTD_CLEVEL_DEFAULT;
          params.fParams.contentSizeFlag = 1;
          params.cParams = cParams;
          {   size_t const dictID = ZSTD_compress_insertDictionary(
                      &cdict->cBlockState, &cdict->matchState, &cdict->workspace,
                      &params, cdict->dictContent, cdict->dictContentSize,
                      dictContentType, ZSTD_dtlm_full, cdict->entropyWorkspace);
              FORWARD_IF_ERROR(dictID);
              assert(dictID <= (size_t)(U32)-1);
              cdict->dictID = (U32)dictID;
          }
      }
  
      return 0;
  }
  
  ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize,
                                        ZSTD_dictLoadMethod_e dictLoadMethod,
                                        ZSTD_dictContentType_e dictContentType,
                                        ZSTD_compressionParameters cParams, ZSTD_customMem customMem)
  {
      DEBUGLOG(3, "ZSTD_createCDict_advanced, mode %u", (unsigned)dictContentType);
      if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
  
      {   size_t const workspaceSize =
              ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict)) +
              ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE) +
              ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0) +
              (dictLoadMethod == ZSTD_dlm_byRef ? 0
               : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void*))));
          void* const workspace = ZSTD_malloc(workspaceSize, customMem);
          ZSTD_cwksp ws;
          ZSTD_CDict* cdict;
  
          if (!workspace) {
              ZSTD_free(workspace, customMem);
              return NULL;
          }
  
          ZSTD_cwksp_init(&ws, workspace, workspaceSize);
  
          cdict = (ZSTD_CDict*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CDict));
          assert(cdict != NULL);
          ZSTD_cwksp_move(&cdict->workspace, &ws);
          cdict->customMem = customMem;
          cdict->compressionLevel = 0; /* signals advanced API usage */
  
          if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
                                          dictBuffer, dictSize,
                                          dictLoadMethod, dictContentType,
                                          cParams) )) {
              ZSTD_freeCDict(cdict);
              return NULL;
          }
  
          return cdict;
      }
  }
  
  ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel)
  {
      ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
      ZSTD_CDict* cdict = ZSTD_createCDict_advanced(dict, dictSize,
                                                    ZSTD_dlm_byCopy, ZSTD_dct_auto,
                                                    cParams, ZSTD_defaultCMem);
      if (cdict)
          cdict->compressionLevel = compressionLevel == 0 ? ZSTD_CLEVEL_DEFAULT : compressionLevel;
      return cdict;
  }
  
  ZSTD_CDict* ZSTD_createCDict_byReference(const void* dict, size_t dictSize, int compressionLevel)
  {
      ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
      return ZSTD_createCDict_advanced(dict, dictSize,
                                       ZSTD_dlm_byRef, ZSTD_dct_auto,
                                       cParams, ZSTD_defaultCMem);
  }
  
  size_t ZSTD_freeCDict(ZSTD_CDict* cdict)
  {
      if (cdict==NULL) return 0;   /* support free on NULL */
      {   ZSTD_customMem const cMem = cdict->customMem;
          int cdictInWorkspace = ZSTD_cwksp_owns_buffer(&cdict->workspace, cdict);
          ZSTD_cwksp_free(&cdict->workspace, cMem);
          if (!cdictInWorkspace) {
              ZSTD_free(cdict, cMem);
          }
          return 0;
      }
  }
  
  /*! ZSTD_initStaticCDict_advanced() :
   *  Generate a digested dictionary in provided memory area.
   *  workspace: The memory area to emplace the dictionary into.
   *             Provided pointer must 8-bytes aligned.
   *             It must outlive dictionary usage.
   *  workspaceSize: Use ZSTD_estimateCDictSize()
   *                 to determine how large workspace must be.
   *  cParams : use ZSTD_getCParams() to transform a compression level
   *            into its relevants cParams.
   * @return : pointer to ZSTD_CDict*, or NULL if error (size too small)
   *  Note : there is no corresponding "free" function.
   *         Since workspace was allocated externally, it must be freed externally.
   */
  const ZSTD_CDict* ZSTD_initStaticCDict(
                                   void* workspace, size_t workspaceSize,
                             const void* dict, size_t dictSize,
                                   ZSTD_dictLoadMethod_e dictLoadMethod,
                                   ZSTD_dictContentType_e dictContentType,
                                   ZSTD_compressionParameters cParams)
  {
      size_t const matchStateSize = ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0);
      size_t const neededSize = ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict))
                              + (dictLoadMethod == ZSTD_dlm_byRef ? 0
                                 : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void*))))
                              + ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE)
                              + matchStateSize;
      ZSTD_CDict* cdict;
  
      if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
  
      {
          ZSTD_cwksp ws;
          ZSTD_cwksp_init(&ws, workspace, workspaceSize);
          cdict = (ZSTD_CDict*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CDict));
          if (cdict == NULL) return NULL;
          ZSTD_cwksp_move(&cdict->workspace, &ws);
      }
  
      DEBUGLOG(4, "(workspaceSize < neededSize) : (%u < %u) => %u",
          (unsigned)workspaceSize, (unsigned)neededSize, (unsigned)(workspaceSize < neededSize));
      if (workspaceSize < neededSize) return NULL;
  
      if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
                                                dict, dictSize,
                                                dictLoadMethod, dictContentType,
                                                cParams) ))
          return NULL;
  
      return cdict;
  }
  
  ZSTD_compressionParameters ZSTD_getCParamsFromCDict(const ZSTD_CDict* cdict)
  {
      assert(cdict != NULL);
      return cdict->matchState.cParams;
  }
  
  /* ZSTD_compressBegin_usingCDict_advanced() :
   * cdict must be != NULL */
  size_t ZSTD_compressBegin_usingCDict_advanced(
      ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict,
      ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize)
  {
      DEBUGLOG(4, "ZSTD_compressBegin_usingCDict_advanced");
      RETURN_ERROR_IF(cdict==NULL, dictionary_wrong);
      {   ZSTD_CCtx_params params = cctx->requestedParams;
          params.cParams = ( pledgedSrcSize < ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF
                          || pledgedSrcSize < cdict->dictContentSize * ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER
                          || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
                          || cdict->compressionLevel == 0 )
                        && (params.attachDictPref != ZSTD_dictForceLoad) ?
                  ZSTD_getCParamsFromCDict(cdict)
                : ZSTD_getCParams(cdict->compressionLevel,
                                  pledgedSrcSize,
                                  cdict->dictContentSize);
          /* Increase window log to fit the entire dictionary and source if the
           * source size is known. Limit the increase to 19, which is the
           * window log for compression level 1 with the largest source size.
           */
          if (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN) {
              U32 const limitedSrcSize = (U32)MIN(pledgedSrcSize, 1U << 19);
              U32 const limitedSrcLog = limitedSrcSize > 1 ? ZSTD_highbit32(limitedSrcSize - 1) + 1 : 1;
              params.cParams.windowLog = MAX(params.cParams.windowLog, limitedSrcLog);
          }
          params.fParams = fParams;
          return ZSTD_compressBegin_internal(cctx,
                                             NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast,
                                             cdict,
                                             &params, pledgedSrcSize,
                                             ZSTDb_not_buffered);
      }
  }
  
  /* ZSTD_compressBegin_usingCDict() :
   * pledgedSrcSize=0 means "unknown"
   * if pledgedSrcSize>0, it will enable contentSizeFlag */
  size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
  {
      ZSTD_frameParameters const fParams = { 0 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
      DEBUGLOG(4, "ZSTD_compressBegin_usingCDict : dictIDFlag == %u", !fParams.noDictIDFlag);
      return ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, ZSTD_CONTENTSIZE_UNKNOWN);
  }
  
  size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
                                  void* dst, size_t dstCapacity,
                                  const void* src, size_t srcSize,
                                  const ZSTD_CDict* cdict, ZSTD_frameParameters fParams)
  {
      FORWARD_IF_ERROR(ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, srcSize));   /* will check if cdict != NULL */
      return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
  }
  
  /*! ZSTD_compress_usingCDict() :
   *  Compression using a digested Dictionary.
   *  Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
   *  Note that compression parameters are decided at CDict creation time
   *  while frame parameters are hardcoded */
  size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
                                  void* dst, size_t dstCapacity,
                                  const void* src, size_t srcSize,
                                  const ZSTD_CDict* cdict)
  {
      ZSTD_frameParameters const fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
      return ZSTD_compress_usingCDict_advanced(cctx, dst, dstCapacity, src, srcSize, cdict, fParams);
  }
  
  
  
  /* ******************************************************************
  *  Streaming
  ********************************************************************/
  
  ZSTD_CStream* ZSTD_createCStream(void)
  {
      DEBUGLOG(3, "ZSTD_createCStream");
      return ZSTD_createCStream_advanced(ZSTD_defaultCMem);
  }
  
  ZSTD_CStream* ZSTD_initStaticCStream(void *workspace, size_t workspaceSize)
  {
      return ZSTD_initStaticCCtx(workspace, workspaceSize);
  }
  
  ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem)
  {   /* CStream and CCtx are now same object */
      return ZSTD_createCCtx_advanced(customMem);
  }
  
  size_t ZSTD_freeCStream(ZSTD_CStream* zcs)
  {
      return ZSTD_freeCCtx(zcs);   /* same object */
  }
  
  
  
  /*======   Initialization   ======*/
  
  size_t ZSTD_CStreamInSize(void)  { return ZSTD_BLOCKSIZE_MAX; }
  
  size_t ZSTD_CStreamOutSize(void)
  {
      return ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + 4 /* 32-bits hash */ ;
  }
  
  static size_t ZSTD_resetCStream_internal(ZSTD_CStream* cctx,
                      const void* const dict, size_t const dictSize, ZSTD_dictContentType_e const dictContentType,
                      const ZSTD_CDict* const cdict,
                      ZSTD_CCtx_params params, unsigned long long const pledgedSrcSize)
  {
      DEBUGLOG(4, "ZSTD_resetCStream_internal");
      /* Finalize the compression parameters */
      params.cParams = ZSTD_getCParamsFromCCtxParams(&params, pledgedSrcSize, dictSize);
      /* params are supposed to be fully validated at this point */
      assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
      assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
  
      FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
                                           dict, dictSize, dictContentType, ZSTD_dtlm_fast,
                                           cdict,
                                           &params, pledgedSrcSize,
                                           ZSTDb_buffered) );
  
      cctx->inToCompress = 0;
      cctx->inBuffPos = 0;
      cctx->inBuffTarget = cctx->blockSize
                        + (cctx->blockSize == pledgedSrcSize);   /* for small input: avoid automatic flush on reaching end of block, since it would require to add a 3-bytes null block to end frame */
      cctx->outBuffContentSize = cctx->outBuffFlushedSize = 0;
      cctx->streamStage = zcss_load;
      cctx->frameEnded = 0;
      return 0;   /* ready to go */
  }
  
  /* ZSTD_resetCStream():
   * pledgedSrcSize == 0 means "unknown" */
  size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pss)
  {
      /* temporary : 0 interpreted as "unknown" during transition period.
       * Users willing to specify "unknown" **must** use ZSTD_CONTENTSIZE_UNKNOWN.
       * 0 will be interpreted as "empty" in the future.
       */
      U64 const pledgedSrcSize = (pss==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
      DEBUGLOG(4, "ZSTD_resetCStream: pledgedSrcSize = %u", (unsigned)pledgedSrcSize);
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
      return 0;
  }
  
  /*! ZSTD_initCStream_internal() :
   *  Note : for lib/compress only. Used by zstdmt_compress.c.
   *  Assumption 1 : params are valid
   *  Assumption 2 : either dict, or cdict, is defined, not both */
  size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
                      const void* dict, size_t dictSize, const ZSTD_CDict* cdict,
                      const ZSTD_CCtx_params* params,
                      unsigned long long pledgedSrcSize)
  {
      DEBUGLOG(4, "ZSTD_initCStream_internal");
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
      assert(!ZSTD_isError(ZSTD_checkCParams(params->cParams)));
      zcs->requestedParams = *params;
      assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
      if (dict) {
          FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) );
      } else {
          /* Dictionary is cleared if !cdict */
          FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) );
      }
      return 0;
  }
  
  /* ZSTD_initCStream_usingCDict_advanced() :
   * same as ZSTD_initCStream_usingCDict(), with control over frame parameters */
  size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs,
                                              const ZSTD_CDict* cdict,
                                              ZSTD_frameParameters fParams,
                                              unsigned long long pledgedSrcSize)
  {
      DEBUGLOG(4, "ZSTD_initCStream_usingCDict_advanced");
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
      zcs->requestedParams.fParams = fParams;
      FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) );
      return 0;
  }
  
  /* note : cdict must outlive compression session */
  size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict)
  {
      DEBUGLOG(4, "ZSTD_initCStream_usingCDict");
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) );
      return 0;
  }
  
  
  /* ZSTD_initCStream_advanced() :
   * pledgedSrcSize must be exact.
   * if srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN.
   * dict is loaded with default parameters ZSTD_dct_auto and ZSTD_dlm_byCopy. */
  size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
                                   const void* dict, size_t dictSize,
                                   ZSTD_parameters params, unsigned long long pss)
  {
      /* for compatibility with older programs relying on this behavior.
       * Users should now specify ZSTD_CONTENTSIZE_UNKNOWN.
       * This line will be removed in the future.
       */
      U64 const pledgedSrcSize = (pss==0 && params.fParams.contentSizeFlag==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
      DEBUGLOG(4, "ZSTD_initCStream_advanced");
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
      FORWARD_IF_ERROR( ZSTD_checkCParams(params.cParams) );
      zcs->requestedParams = ZSTD_assignParamsToCCtxParams(&zcs->requestedParams, params);
      FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) );
      return 0;
  }
  
  size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel)
  {
      DEBUGLOG(4, "ZSTD_initCStream_usingDict");
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) );
      FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) );
      return 0;
  }
  
  size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pss)
  {
      /* temporary : 0 interpreted as "unknown" during transition period.
       * Users willing to specify "unknown" **must** use ZSTD_CONTENTSIZE_UNKNOWN.
       * 0 will be interpreted as "empty" in the future.
       */
      U64 const pledgedSrcSize = (pss==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
      DEBUGLOG(4, "ZSTD_initCStream_srcSize");
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, NULL) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
      return 0;
  }
  
  size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel)
  {
      DEBUGLOG(4, "ZSTD_initCStream");
      FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
      FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, NULL) );
      FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) );
      return 0;
  }
  
  /*======   Compression   ======*/
  
  static size_t ZSTD_nextInputSizeHint(const ZSTD_CCtx* cctx)
  {
      size_t hintInSize = cctx->inBuffTarget - cctx->inBuffPos;
      if (hintInSize==0) hintInSize = cctx->blockSize;
      return hintInSize;
  }
  
  static size_t ZSTD_limitCopy(void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize)
  {
      size_t const length = MIN(dstCapacity, srcSize);
      if (length) memcpy(dst, src, length);
      return length;
  }
  
  /** ZSTD_compressStream_generic():
   *  internal function for all *compressStream*() variants
   *  non-static, because can be called from zstdmt_compress.c
   * @return : hint size for next input */
  static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                            ZSTD_outBuffer* output,
                                            ZSTD_inBuffer* input,
                                            ZSTD_EndDirective const flushMode)
  {
      const char* const istart = (const char*)input->src;
      const char* const iend = istart + input->size;
      const char* ip = istart + input->pos;
      char* const ostart = (char*)output->dst;
      char* const oend = ostart + output->size;
      char* op = ostart + output->pos;
      U32 someMoreWork = 1;
  
      /* check expectations */
      DEBUGLOG(5, "ZSTD_compressStream_generic, flush=%u", (unsigned)flushMode);
      assert(zcs->inBuff != NULL);
      assert(zcs->inBuffSize > 0);
      assert(zcs->outBuff !=  NULL);
      assert(zcs->outBuffSize > 0);
      assert(output->pos <= output->size);
      assert(input->pos <= input->size);
  
      while (someMoreWork) {
          switch(zcs->streamStage)
          {
          case zcss_init:
              RETURN_ERROR(init_missing, "call ZSTD_initCStream() first!");
  
          case zcss_load:
              if ( (flushMode == ZSTD_e_end)
                && ((size_t)(oend-op) >= ZSTD_compressBound(iend-ip))  /* enough dstCapacity */
                && (zcs->inBuffPos == 0) ) {
                  /* shortcut to compression pass directly into output buffer */
                  size_t const cSize = ZSTD_compressEnd(zcs,
                                                  op, oend-op, ip, iend-ip);
                  DEBUGLOG(4, "ZSTD_compressEnd : cSize=%u", (unsigned)cSize);
                  FORWARD_IF_ERROR(cSize);
                  ip = iend;
                  op += cSize;
                  zcs->frameEnded = 1;
                  ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
                  someMoreWork = 0; break;
              }
              /* complete loading into inBuffer */
              {   size_t const toLoad = zcs->inBuffTarget - zcs->inBuffPos;
                  size_t const loaded = ZSTD_limitCopy(
                                          zcs->inBuff + zcs->inBuffPos, toLoad,
                                          ip, iend-ip);
                  zcs->inBuffPos += loaded;
                  ip += loaded;
                  if ( (flushMode == ZSTD_e_continue)
                    && (zcs->inBuffPos < zcs->inBuffTarget) ) {
                      /* not enough input to fill full block : stop here */
                      someMoreWork = 0; break;
                  }
                  if ( (flushMode == ZSTD_e_flush)
                    && (zcs->inBuffPos == zcs->inToCompress) ) {
                      /* empty */
                      someMoreWork = 0; break;
                  }
              }
              /* compress current block (note : this stage cannot be stopped in the middle) */
              DEBUGLOG(5, "stream compression stage (flushMode==%u)", flushMode);
              {   void* cDst;
                  size_t cSize;
                  size_t const iSize = zcs->inBuffPos - zcs->inToCompress;
                  size_t oSize = oend-op;
                  unsigned const lastBlock = (flushMode == ZSTD_e_end) && (ip==iend);
                  if (oSize >= ZSTD_compressBound(iSize))
                      cDst = op;   /* compress into output buffer, to skip flush stage */
                  else
                      cDst = zcs->outBuff, oSize = zcs->outBuffSize;
                  cSize = lastBlock ?
                          ZSTD_compressEnd(zcs, cDst, oSize,
                                      zcs->inBuff + zcs->inToCompress, iSize) :
                          ZSTD_compressContinue(zcs, cDst, oSize,
                                      zcs->inBuff + zcs->inToCompress, iSize);
                  FORWARD_IF_ERROR(cSize);
                  zcs->frameEnded = lastBlock;
                  /* prepare next block */
                  zcs->inBuffTarget = zcs->inBuffPos + zcs->blockSize;
                  if (zcs->inBuffTarget > zcs->inBuffSize)
                      zcs->inBuffPos = 0, zcs->inBuffTarget = zcs->blockSize;
                  DEBUGLOG(5, "inBuffTarget:%u / inBuffSize:%u",
                           (unsigned)zcs->inBuffTarget, (unsigned)zcs->inBuffSize);
                  if (!lastBlock)
                      assert(zcs->inBuffTarget <= zcs->inBuffSize);
                  zcs->inToCompress = zcs->inBuffPos;
                  if (cDst == op) {  /* no need to flush */
                      op += cSize;
                      if (zcs->frameEnded) {
                          DEBUGLOG(5, "Frame completed directly in outBuffer");
                          someMoreWork = 0;
                          ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
                      }
                      break;
                  }
                  zcs->outBuffContentSize = cSize;
                  zcs->outBuffFlushedSize = 0;
                  zcs->streamStage = zcss_flush; /* pass-through to flush stage */
              }
  	    /* fall-through */
          case zcss_flush:
              DEBUGLOG(5, "flush stage");
              {   size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
                  size_t const flushed = ZSTD_limitCopy(op, (size_t)(oend-op),
                              zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
                  DEBUGLOG(5, "toFlush: %u into %u ==> flushed: %u",
                              (unsigned)toFlush, (unsigned)(oend-op), (unsigned)flushed);
                  op += flushed;
                  zcs->outBuffFlushedSize += flushed;
                  if (toFlush!=flushed) {
                      /* flush not fully completed, presumably because dst is too small */
                      assert(op==oend);
                      someMoreWork = 0;
                      break;
                  }
                  zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
                  if (zcs->frameEnded) {
                      DEBUGLOG(5, "Frame completed on flush");
                      someMoreWork = 0;
                      ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
                      break;
                  }
                  zcs->streamStage = zcss_load;
                  break;
              }
  
          default: /* impossible */
              assert(0);
          }
      }
  
      input->pos = ip - istart;
      output->pos = op - ostart;
      if (zcs->frameEnded) return 0;
      return ZSTD_nextInputSizeHint(zcs);
  }
  
  static size_t ZSTD_nextInputSizeHint_MTorST(const ZSTD_CCtx* cctx)
  {
  #ifdef ZSTD_MULTITHREAD
      if (cctx->appliedParams.nbWorkers >= 1) {
          assert(cctx->mtctx != NULL);
          return ZSTDMT_nextInputSizeHint(cctx->mtctx);
      }
  #endif
      return ZSTD_nextInputSizeHint(cctx);
  
  }
  
  size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
  {
      FORWARD_IF_ERROR( ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue) );
      return ZSTD_nextInputSizeHint_MTorST(zcs);
  }
  
  
  size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
                               ZSTD_outBuffer* output,
                               ZSTD_inBuffer* input,
                               ZSTD_EndDirective endOp)
  {
      DEBUGLOG(5, "ZSTD_compressStream2, endOp=%u ", (unsigned)endOp);
      /* check conditions */
      RETURN_ERROR_IF(output->pos > output->size, GENERIC);
      RETURN_ERROR_IF(input->pos  > input->size, GENERIC);
      assert(cctx!=NULL);
  
      /* transparent initialization stage */
      if (cctx->streamStage == zcss_init) {
          ZSTD_CCtx_params params = cctx->requestedParams;
          ZSTD_prefixDict const prefixDict = cctx->prefixDict;
          FORWARD_IF_ERROR( ZSTD_initLocalDict(cctx) ); /* Init the local dict if present. */
          memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));   /* single usage */
          assert(prefixDict.dict==NULL || cctx->cdict==NULL);    /* only one can be set */
          DEBUGLOG(4, "ZSTD_compressStream2 : transparent init stage");
          if (endOp == ZSTD_e_end) cctx->pledgedSrcSizePlusOne = input->size + 1;  /* auto-fix pledgedSrcSize */
          params.cParams = ZSTD_getCParamsFromCCtxParams(
                  &cctx->requestedParams, cctx->pledgedSrcSizePlusOne-1, 0 /*dictSize*/);
  
  
  #ifdef ZSTD_MULTITHREAD
          if ((cctx->pledgedSrcSizePlusOne-1) <= ZSTDMT_JOBSIZE_MIN) {
              params.nbWorkers = 0; /* do not invoke multi-threading when src size is too small */
          }
          if (params.nbWorkers > 0) {
              /* mt context creation */
              if (cctx->mtctx == NULL) {
                  DEBUGLOG(4, "ZSTD_compressStream2: creating new mtctx for nbWorkers=%u",
                              params.nbWorkers);
                  cctx->mtctx = ZSTDMT_createCCtx_advanced((U32)params.nbWorkers, cctx->customMem);
                  RETURN_ERROR_IF(cctx->mtctx == NULL, memory_allocation);
              }
              /* mt compression */
              DEBUGLOG(4, "call ZSTDMT_initCStream_internal as nbWorkers=%u", params.nbWorkers);
              FORWARD_IF_ERROR( ZSTDMT_initCStream_internal(
                          cctx->mtctx,
                          prefixDict.dict, prefixDict.dictSize, ZSTD_dct_rawContent,
                          cctx->cdict, params, cctx->pledgedSrcSizePlusOne-1) );
              cctx->streamStage = zcss_load;
              cctx->appliedParams.nbWorkers = params.nbWorkers;
          } else
  #endif
          {   FORWARD_IF_ERROR( ZSTD_resetCStream_internal(cctx,
                              prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType,
                              cctx->cdict,
                              params, cctx->pledgedSrcSizePlusOne-1) );
              assert(cctx->streamStage == zcss_load);
              assert(cctx->appliedParams.nbWorkers == 0);
      }   }
      /* end of transparent initialization stage */
  
      /* compression stage */
  #ifdef ZSTD_MULTITHREAD
      if (cctx->appliedParams.nbWorkers > 0) {
          int const forceMaxProgress = (endOp == ZSTD_e_flush || endOp == ZSTD_e_end);
          size_t flushMin;
          assert(forceMaxProgress || endOp == ZSTD_e_continue /* Protection for a new flush type */);
          if (cctx->cParamsChanged) {
              ZSTDMT_updateCParams_whileCompressing(cctx->mtctx, &cctx->requestedParams);
              cctx->cParamsChanged = 0;
          }
          do {
              flushMin = ZSTDMT_compressStream_generic(cctx->mtctx, output, input, endOp);
              if ( ZSTD_isError(flushMin)
                || (endOp == ZSTD_e_end && flushMin == 0) ) { /* compression completed */
                  ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
              }
              FORWARD_IF_ERROR(flushMin);
          } while (forceMaxProgress && flushMin != 0 && output->pos < output->size);
          DEBUGLOG(5, "completed ZSTD_compressStream2 delegating to ZSTDMT_compressStream_generic");
          /* Either we don't require maximum forward progress, we've finished the
           * flush, or we are out of output space.
           */
          assert(!forceMaxProgress || flushMin == 0 || output->pos == output->size);
          return flushMin;
      }
  #endif
      FORWARD_IF_ERROR( ZSTD_compressStream_generic(cctx, output, input, endOp) );
      DEBUGLOG(5, "completed ZSTD_compressStream2");
      return cctx->outBuffContentSize - cctx->outBuffFlushedSize; /* remaining to flush */
  }
  
  size_t ZSTD_compressStream2_simpleArgs (
                              ZSTD_CCtx* cctx,
                              void* dst, size_t dstCapacity, size_t* dstPos,
                        const void* src, size_t srcSize, size_t* srcPos,
                              ZSTD_EndDirective endOp)
  {
      ZSTD_outBuffer output = { dst, dstCapacity, *dstPos };
      ZSTD_inBuffer  input  = { src, srcSize, *srcPos };
      /* ZSTD_compressStream2() will check validity of dstPos and srcPos */
      size_t const cErr = ZSTD_compressStream2(cctx, &output, &input, endOp);
      *dstPos = output.pos;
      *srcPos = input.pos;
      return cErr;
  }
  
  size_t ZSTD_compress2(ZSTD_CCtx* cctx,
                        void* dst, size_t dstCapacity,
                        const void* src, size_t srcSize)
  {
      ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
      {   size_t oPos = 0;
          size_t iPos = 0;
          size_t const result = ZSTD_compressStream2_simpleArgs(cctx,
                                          dst, dstCapacity, &oPos,
                                          src, srcSize, &iPos,
                                          ZSTD_e_end);
          FORWARD_IF_ERROR(result);
          if (result != 0) {  /* compression not completed, due to lack of output space */
              assert(oPos == dstCapacity);
              RETURN_ERROR(dstSize_tooSmall);
          }
          assert(iPos == srcSize);   /* all input is expected consumed */
          return oPos;
      }
  }
  
  /*======   Finalize   ======*/
  
  /*! ZSTD_flushStream() :
   * @return : amount of data remaining to flush */
  size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
  {
      ZSTD_inBuffer input = { NULL, 0, 0 };
      return ZSTD_compressStream2(zcs, output, &input, ZSTD_e_flush);
  }
  
  
  size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
  {
      ZSTD_inBuffer input = { NULL, 0, 0 };
      size_t const remainingToFlush = ZSTD_compressStream2(zcs, output, &input, ZSTD_e_end);
      FORWARD_IF_ERROR( remainingToFlush );
      if (zcs->appliedParams.nbWorkers > 0) return remainingToFlush;   /* minimal estimation */
      /* single thread mode : attempt to calculate remaining to flush more precisely */
      {   size_t const lastBlockSize = zcs->frameEnded ? 0 : ZSTD_BLOCKHEADERSIZE;
          size_t const checksumSize = (size_t)(zcs->frameEnded ? 0 : zcs->appliedParams.fParams.checksumFlag * 4);
          size_t const toFlush = remainingToFlush + lastBlockSize + checksumSize;
          DEBUGLOG(4, "ZSTD_endStream : remaining to flush : %u", (unsigned)toFlush);
          return toFlush;
      }
  }
  
  
  /*-=====  Pre-defined compression levels  =====-*/
  
  #define ZSTD_MAX_CLEVEL     22
  int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
  int ZSTD_minCLevel(void) { return (int)-ZSTD_TARGETLENGTH_MAX; }
  
  static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEVEL+1] = {
  {   /* "default" - for any srcSize > 256 KB */
      /* W,  C,  H,  S,  L, TL, strat */
      { 19, 12, 13,  1,  6,  1, ZSTD_fast    },  /* base for negative levels */
      { 19, 13, 14,  1,  7,  0, ZSTD_fast    },  /* level  1 */
      { 20, 15, 16,  1,  6,  0, ZSTD_fast    },  /* level  2 */
      { 21, 16, 17,  1,  5,  0, ZSTD_dfast   },  /* level  3 */
      { 21, 18, 18,  1,  5,  0, ZSTD_dfast   },  /* level  4 */
      { 21, 18, 19,  2,  5,  2, ZSTD_greedy  },  /* level  5 */
      { 21, 19, 19,  3,  5,  4, ZSTD_greedy  },  /* level  6 */
      { 21, 19, 19,  3,  5,  8, ZSTD_lazy    },  /* level  7 */
      { 21, 19, 19,  3,  5, 16, ZSTD_lazy2   },  /* level  8 */
      { 21, 19, 20,  4,  5, 16, ZSTD_lazy2   },  /* level  9 */
      { 22, 20, 21,  4,  5, 16, ZSTD_lazy2   },  /* level 10 */
      { 22, 21, 22,  4,  5, 16, ZSTD_lazy2   },  /* level 11 */
      { 22, 21, 22,  5,  5, 16, ZSTD_lazy2   },  /* level 12 */
      { 22, 21, 22,  5,  5, 32, ZSTD_btlazy2 },  /* level 13 */
      { 22, 22, 23,  5,  5, 32, ZSTD_btlazy2 },  /* level 14 */
      { 22, 23, 23,  6,  5, 32, ZSTD_btlazy2 },  /* level 15 */
      { 22, 22, 22,  5,  5, 48, ZSTD_btopt   },  /* level 16 */
      { 23, 23, 22,  5,  4, 64, ZSTD_btopt   },  /* level 17 */
      { 23, 23, 22,  6,  3, 64, ZSTD_btultra },  /* level 18 */
      { 23, 24, 22,  7,  3,256, ZSTD_btultra2},  /* level 19 */
      { 25, 25, 23,  7,  3,256, ZSTD_btultra2},  /* level 20 */
      { 26, 26, 24,  7,  3,512, ZSTD_btultra2},  /* level 21 */
      { 27, 27, 25,  9,  3,999, ZSTD_btultra2},  /* level 22 */
  },
  {   /* for srcSize <= 256 KB */
      /* W,  C,  H,  S,  L,  T, strat */
      { 18, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
      { 18, 13, 14,  1,  6,  0, ZSTD_fast    },  /* level  1 */
      { 18, 14, 14,  1,  5,  0, ZSTD_dfast   },  /* level  2 */
      { 18, 16, 16,  1,  4,  0, ZSTD_dfast   },  /* level  3 */
      { 18, 16, 17,  2,  5,  2, ZSTD_greedy  },  /* level  4.*/
      { 18, 18, 18,  3,  5,  2, ZSTD_greedy  },  /* level  5.*/
      { 18, 18, 19,  3,  5,  4, ZSTD_lazy    },  /* level  6.*/
      { 18, 18, 19,  4,  4,  4, ZSTD_lazy    },  /* level  7 */
      { 18, 18, 19,  4,  4,  8, ZSTD_lazy2   },  /* level  8 */
      { 18, 18, 19,  5,  4,  8, ZSTD_lazy2   },  /* level  9 */
      { 18, 18, 19,  6,  4,  8, ZSTD_lazy2   },  /* level 10 */
      { 18, 18, 19,  5,  4, 12, ZSTD_btlazy2 },  /* level 11.*/
      { 18, 19, 19,  7,  4, 12, ZSTD_btlazy2 },  /* level 12.*/
      { 18, 18, 19,  4,  4, 16, ZSTD_btopt   },  /* level 13 */
      { 18, 18, 19,  4,  3, 32, ZSTD_btopt   },  /* level 14.*/
      { 18, 18, 19,  6,  3,128, ZSTD_btopt   },  /* level 15.*/
      { 18, 19, 19,  6,  3,128, ZSTD_btultra },  /* level 16.*/
      { 18, 19, 19,  8,  3,256, ZSTD_btultra },  /* level 17.*/
      { 18, 19, 19,  6,  3,128, ZSTD_btultra2},  /* level 18.*/
      { 18, 19, 19,  8,  3,256, ZSTD_btultra2},  /* level 19.*/
      { 18, 19, 19, 10,  3,512, ZSTD_btultra2},  /* level 20.*/
      { 18, 19, 19, 12,  3,512, ZSTD_btultra2},  /* level 21.*/
      { 18, 19, 19, 13,  3,999, ZSTD_btultra2},  /* level 22.*/
  },
  {   /* for srcSize <= 128 KB */
      /* W,  C,  H,  S,  L,  T, strat */
      { 17, 12, 12,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
      { 17, 12, 13,  1,  6,  0, ZSTD_fast    },  /* level  1 */
      { 17, 13, 15,  1,  5,  0, ZSTD_fast    },  /* level  2 */
      { 17, 15, 16,  2,  5,  0, ZSTD_dfast   },  /* level  3 */
      { 17, 17, 17,  2,  4,  0, ZSTD_dfast   },  /* level  4 */
      { 17, 16, 17,  3,  4,  2, ZSTD_greedy  },  /* level  5 */
      { 17, 17, 17,  3,  4,  4, ZSTD_lazy    },  /* level  6 */
      { 17, 17, 17,  3,  4,  8, ZSTD_lazy2   },  /* level  7 */
      { 17, 17, 17,  4,  4,  8, ZSTD_lazy2   },  /* level  8 */
      { 17, 17, 17,  5,  4,  8, ZSTD_lazy2   },  /* level  9 */
      { 17, 17, 17,  6,  4,  8, ZSTD_lazy2   },  /* level 10 */
      { 17, 17, 17,  5,  4,  8, ZSTD_btlazy2 },  /* level 11 */
      { 17, 18, 17,  7,  4, 12, ZSTD_btlazy2 },  /* level 12 */
      { 17, 18, 17,  3,  4, 12, ZSTD_btopt   },  /* level 13.*/
      { 17, 18, 17,  4,  3, 32, ZSTD_btopt   },  /* level 14.*/
      { 17, 18, 17,  6,  3,256, ZSTD_btopt   },  /* level 15.*/
      { 17, 18, 17,  6,  3,128, ZSTD_btultra },  /* level 16.*/
      { 17, 18, 17,  8,  3,256, ZSTD_btultra },  /* level 17.*/
      { 17, 18, 17, 10,  3,512, ZSTD_btultra },  /* level 18.*/
      { 17, 18, 17,  5,  3,256, ZSTD_btultra2},  /* level 19.*/
      { 17, 18, 17,  7,  3,512, ZSTD_btultra2},  /* level 20.*/
      { 17, 18, 17,  9,  3,512, ZSTD_btultra2},  /* level 21.*/
      { 17, 18, 17, 11,  3,999, ZSTD_btultra2},  /* level 22.*/
  },
  {   /* for srcSize <= 16 KB */
      /* W,  C,  H,  S,  L,  T, strat */
      { 14, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
      { 14, 14, 15,  1,  5,  0, ZSTD_fast    },  /* level  1 */
      { 14, 14, 15,  1,  4,  0, ZSTD_fast    },  /* level  2 */
      { 14, 14, 15,  2,  4,  0, ZSTD_dfast   },  /* level  3 */
      { 14, 14, 14,  4,  4,  2, ZSTD_greedy  },  /* level  4 */
      { 14, 14, 14,  3,  4,  4, ZSTD_lazy    },  /* level  5.*/
      { 14, 14, 14,  4,  4,  8, ZSTD_lazy2   },  /* level  6 */
      { 14, 14, 14,  6,  4,  8, ZSTD_lazy2   },  /* level  7 */
      { 14, 14, 14,  8,  4,  8, ZSTD_lazy2   },  /* level  8.*/
      { 14, 15, 14,  5,  4,  8, ZSTD_btlazy2 },  /* level  9.*/
      { 14, 15, 14,  9,  4,  8, ZSTD_btlazy2 },  /* level 10.*/
      { 14, 15, 14,  3,  4, 12, ZSTD_btopt   },  /* level 11.*/
      { 14, 15, 14,  4,  3, 24, ZSTD_btopt   },  /* level 12.*/
      { 14, 15, 14,  5,  3, 32, ZSTD_btultra },  /* level 13.*/
      { 14, 15, 15,  6,  3, 64, ZSTD_btultra },  /* level 14.*/
      { 14, 15, 15,  7,  3,256, ZSTD_btultra },  /* level 15.*/
      { 14, 15, 15,  5,  3, 48, ZSTD_btultra2},  /* level 16.*/
      { 14, 15, 15,  6,  3,128, ZSTD_btultra2},  /* level 17.*/
      { 14, 15, 15,  7,  3,256, ZSTD_btultra2},  /* level 18.*/
      { 14, 15, 15,  8,  3,256, ZSTD_btultra2},  /* level 19.*/
      { 14, 15, 15,  8,  3,512, ZSTD_btultra2},  /* level 20.*/
      { 14, 15, 15,  9,  3,512, ZSTD_btultra2},  /* level 21.*/
      { 14, 15, 15, 10,  3,999, ZSTD_btultra2},  /* level 22.*/
  },
  };
  
  /*! ZSTD_getCParams() :
   * @return ZSTD_compressionParameters structure for a selected compression level, srcSize and dictSize.
   *  Size values are optional, provide 0 if not known or unused */
  ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize)
  {
      size_t const addedSize = srcSizeHint ? 0 : 500;
      U64 const rSize = srcSizeHint+dictSize ? srcSizeHint+dictSize+addedSize : ZSTD_CONTENTSIZE_UNKNOWN;  /* intentional overflow for srcSizeHint == ZSTD_CONTENTSIZE_UNKNOWN */
      U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB);
      int row = compressionLevel;
      DEBUGLOG(5, "ZSTD_getCParams (cLevel=%i)", compressionLevel);
      if (compressionLevel == 0) row = ZSTD_CLEVEL_DEFAULT;   /* 0 == default */
      if (compressionLevel < 0) row = 0;   /* entry 0 is baseline for fast mode */
      if (compressionLevel > ZSTD_MAX_CLEVEL) row = ZSTD_MAX_CLEVEL;
      {   ZSTD_compressionParameters cp = ZSTD_defaultCParameters[tableID][row];
          if (compressionLevel < 0) cp.targetLength = (unsigned)(-compressionLevel);   /* acceleration factor */
          return ZSTD_adjustCParams_internal(cp, srcSizeHint, dictSize);               /* refine parameters based on srcSize & dictSize */
      }
  }
  
  /*! ZSTD_getParams() :
   *  same idea as ZSTD_getCParams()
   * @return a `ZSTD_parameters` structure (instead of `ZSTD_compressionParameters`).
   *  Fields of `ZSTD_frameParameters` are set to default values */
  ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize) {
      ZSTD_parameters params;
      ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, srcSizeHint, dictSize);
      DEBUGLOG(5, "ZSTD_getParams (cLevel=%i)", compressionLevel);
      memset(&params, 0, sizeof(params));
      params.cParams = cParams;
      params.fParams.contentSizeFlag = 1;
      return params;
  }
  