ceph/src/zstd/lib/deprecated/zbuff_compress.c

   1 /*
   2  * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under both the BSD-style license (found in the
   6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
   7  * in the COPYING file in the root directory of this source tree).
   8  * You may select, at your option, one of the above-listed licenses.
   9  */
  10
  11
  12
  13 /* *************************************
  14 *  Dependencies
  15 ***************************************/
  16 #define ZBUFF_STATIC_LINKING_ONLY
  17 #include "zbuff.h"
  18
  19
  20 /*-***********************************************************
  21 *  Streaming compression
  22 *
  23 *  A ZBUFF_CCtx object is required to track streaming operation.
  24 *  Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.
  25 *  Use ZBUFF_compressInit() to start a new compression operation.
  26 *  ZBUFF_CCtx objects can be reused multiple times.
  27 *
  28 *  Use ZBUFF_compressContinue() repetitively to consume your input.
  29 *  *srcSizePtr and *dstCapacityPtr can be any size.
  30 *  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
  31 *  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.
  32 *  The content of dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change dst .
  33 *  @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency)
  34 *            or an error code, which can be tested using ZBUFF_isError().
  35 *
  36 *  ZBUFF_compressFlush() can be used to instruct ZBUFF to compress and output whatever remains within its buffer.
  37 *  Note that it will not output more than *dstCapacityPtr.
  38 *  Therefore, some content might still be left into its internal buffer if dst buffer is too small.
  39 *  @return : nb of bytes still present into internal buffer (0 if it's empty)
  40 *            or an error code, which can be tested using ZBUFF_isError().
  41 *
  42 *  ZBUFF_compressEnd() instructs to finish a frame.
  43 *  It will perform a flush and write frame epilogue.
  44 *  Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
  45 *  @return : nb of bytes still present into internal buffer (0 if it's empty)
  46 *            or an error code, which can be tested using ZBUFF_isError().
  47 *
  48 *  Hint : recommended buffer sizes (not compulsory)
  49 *  input : ZSTD_BLOCKSIZE_MAX (128 KB), internal unit size, it improves latency to use this value.
  50 *  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.
  51 * ***********************************************************/
  52
  53 ZBUFF_CCtx* ZBUFF_createCCtx(void)
  54 {
  55     return ZSTD_createCStream();
  56 }
  57
  58 ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem)
  59 {
  60     return ZSTD_createCStream_advanced(customMem);
  61 }
  62
  63 size_t ZBUFF_freeCCtx(ZBUFF_CCtx* zbc)
  64 {
  65     return ZSTD_freeCStream(zbc);
  66 }
  67
  68
  69 /* ======   Initialization   ====== */
  70
  71 size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,
  72                                    const void* dict, size_t dictSize,
  73                                    ZSTD_parameters params, unsigned long long pledgedSrcSize)
  74 {
  75     if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* preserve "0 == unknown" behavior */
  76     return ZSTD_initCStream_advanced(zbc, dict, dictSize, params, pledgedSrcSize);
  77 }
  78
  79
  80 size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* zbc, const void* dict, size_t dictSize, int compressionLevel)
  81 {
  82     return ZSTD_initCStream_usingDict(zbc, dict, dictSize, compressionLevel);
  83 }
  84
  85 size_t ZBUFF_compressInit(ZBUFF_CCtx* zbc, int compressionLevel)
  86 {
  87     return ZSTD_initCStream(zbc, compressionLevel);
  88 }
  89
  90 /* ======   Compression   ====== */
  91
  92
  93 size_t ZBUFF_compressContinue(ZBUFF_CCtx* zbc,
  94                               void* dst, size_t* dstCapacityPtr,
  95                         const void* src, size_t* srcSizePtr)
  96 {
  97     size_t result;
  98     ZSTD_outBuffer outBuff;
  99     ZSTD_inBuffer inBuff;
 100     outBuff.dst = dst;
 101     outBuff.pos = 0;
 102     outBuff.size = *dstCapacityPtr;
 103     inBuff.src = src;
 104     inBuff.pos = 0;
 105     inBuff.size = *srcSizePtr;
 106     result = ZSTD_compressStream(zbc, &outBuff, &inBuff);
 107     *dstCapacityPtr = outBuff.pos;
 108     *srcSizePtr = inBuff.pos;
 109     return result;
 110 }
 111
 112
 113
 114 /* ======   Finalize   ====== */
 115
 116 size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
 117 {
 118     size_t result;
 119     ZSTD_outBuffer outBuff;
 120     outBuff.dst = dst;
 121     outBuff.pos = 0;
 122     outBuff.size = *dstCapacityPtr;
 123     result = ZSTD_flushStream(zbc, &outBuff);
 124     *dstCapacityPtr = outBuff.pos;
 125     return result;
 126 }
 127
 128
 129 size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
 130 {
 131     size_t result;
 132     ZSTD_outBuffer outBuff;
 133     outBuff.dst = dst;
 134     outBuff.pos = 0;
 135     outBuff.size = *dstCapacityPtr;
 136     result = ZSTD_endStream(zbc, &outBuff);
 137     *dstCapacityPtr = outBuff.pos;
 138     return result;
 139 }
 140
 141
 142
 143 /* *************************************
 144 *  Tool functions
 145 ***************************************/
 146 size_t ZBUFF_recommendedCInSize(void)  { return ZSTD_CStreamInSize(); }
 147 size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_CStreamOutSize(); }