FreeBSD/Linux Kernel Cross Reference
sys/contrib/zstd/lib/deprecated/zbuff_compress.c

     /*
      * Copyright (c) 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
    ***************************************/
    #define ZBUFF_STATIC_LINKING_ONLY
    #include "zbuff.h"
    #include "../common/error_private.h"
    
    
    /*-***********************************************************
    *  Streaming compression
    *
    *  A ZBUFF_CCtx object is required to track streaming operation.
    *  Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.
    *  Use ZBUFF_compressInit() to start a new compression operation.
    *  ZBUFF_CCtx objects can be reused multiple times.
    *
    *  Use ZBUFF_compressContinue() repetitively to consume your input.
    *  *srcSizePtr and *dstCapacityPtr can be any size.
    *  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
    *  Note that it may not consume the entire input, in which case it's up to the caller to call again the function with remaining input.
    *  The content of dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change dst .
    *  @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency)
    *            or an error code, which can be tested using ZBUFF_isError().
    *
    *  ZBUFF_compressFlush() can be used to instruct ZBUFF to compress and output whatever remains within its buffer.
    *  Note that it will not output more than *dstCapacityPtr.
    *  Therefore, some content might still be left into its internal buffer if dst buffer is too small.
    *  @return : nb of bytes still present into internal buffer (0 if it's empty)
    *            or an error code, which can be tested using ZBUFF_isError().
    *
    *  ZBUFF_compressEnd() instructs to finish a frame.
    *  It will perform a flush and write frame epilogue.
    *  Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
    *  @return : nb of bytes still present into internal buffer (0 if it's empty)
    *            or an error code, which can be tested using ZBUFF_isError().
    *
    *  Hint : recommended buffer sizes (not compulsory)
    *  input : ZSTD_BLOCKSIZE_MAX (128 KB), internal unit size, it improves latency to use this value.
    *  output : ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + ZBUFF_endFrameSize : ensures it's always possible to write/flush/end a full block at best speed.
    * ***********************************************************/
    
    ZBUFF_CCtx* ZBUFF_createCCtx(void)
    {
        return ZSTD_createCStream();
    }
    
    ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem)
    {
        return ZSTD_createCStream_advanced(customMem);
    }
    
    size_t ZBUFF_freeCCtx(ZBUFF_CCtx* zbc)
    {
        return ZSTD_freeCStream(zbc);
    }
    
    
    /* ======   Initialization   ====== */
    
    size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,
                                       const void* dict, size_t dictSize,
                                       ZSTD_parameters params, unsigned long long pledgedSrcSize)
    {
        if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* preserve "0 == unknown" behavior */
        FORWARD_IF_ERROR(ZSTD_CCtx_reset(zbc, ZSTD_reset_session_only), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setPledgedSrcSize(zbc, pledgedSrcSize), "");
    
        FORWARD_IF_ERROR(ZSTD_checkCParams(params.cParams), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_windowLog, params.cParams.windowLog), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_hashLog, params.cParams.hashLog), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_chainLog, params.cParams.chainLog), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_searchLog, params.cParams.searchLog), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_minMatch, params.cParams.minMatch), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_targetLength, params.cParams.targetLength), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_strategy, params.cParams.strategy), "");
    
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_contentSizeFlag, params.fParams.contentSizeFlag), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_checksumFlag, params.fParams.checksumFlag), "");
        FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_dictIDFlag, params.fParams.noDictIDFlag), "");
    
        FORWARD_IF_ERROR(ZSTD_CCtx_loadDictionary(zbc, dict, dictSize), "");
        return 0;
    }
    
    size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* zbc, const void* dict, size_t dictSize, int compressionLevel)
    {
        FORWARD_IF_ERROR(ZSTD_CCtx_reset(zbc, ZSTD_reset_session_only), "");
       FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_compressionLevel, compressionLevel), "");
       FORWARD_IF_ERROR(ZSTD_CCtx_loadDictionary(zbc, dict, dictSize), "");
       return 0;
   }
   
   size_t ZBUFF_compressInit(ZBUFF_CCtx* zbc, int compressionLevel)
   {
       return ZSTD_initCStream(zbc, compressionLevel);
   }
   
   /* ======   Compression   ====== */
   
   
   size_t ZBUFF_compressContinue(ZBUFF_CCtx* zbc,
                                 void* dst, size_t* dstCapacityPtr,
                           const void* src, size_t* srcSizePtr)
   {
       size_t result;
       ZSTD_outBuffer outBuff;
       ZSTD_inBuffer inBuff;
       outBuff.dst = dst;
       outBuff.pos = 0;
       outBuff.size = *dstCapacityPtr;
       inBuff.src = src;
       inBuff.pos = 0;
       inBuff.size = *srcSizePtr;
       result = ZSTD_compressStream(zbc, &outBuff, &inBuff);
       *dstCapacityPtr = outBuff.pos;
       *srcSizePtr = inBuff.pos;
       return result;
   }
   
   
   
   /* ======   Finalize   ====== */
   
   size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
   {
       size_t result;
       ZSTD_outBuffer outBuff;
       outBuff.dst = dst;
       outBuff.pos = 0;
       outBuff.size = *dstCapacityPtr;
       result = ZSTD_flushStream(zbc, &outBuff);
       *dstCapacityPtr = outBuff.pos;
       return result;
   }
   
   
   size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
   {
       size_t result;
       ZSTD_outBuffer outBuff;
       outBuff.dst = dst;
       outBuff.pos = 0;
       outBuff.size = *dstCapacityPtr;
       result = ZSTD_endStream(zbc, &outBuff);
       *dstCapacityPtr = outBuff.pos;
       return result;
   }
   
   
   
   /* *************************************
   *  Tool functions
   ***************************************/
   size_t ZBUFF_recommendedCInSize(void)  { return ZSTD_CStreamInSize(); }
   size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_CStreamOutSize(); }

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