ceph/src/zstd/lib/legacy/zstd_v07.h

   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 #ifndef ZSTDv07_H_235446
  12 #define ZSTDv07_H_235446
  13
  14 #if defined (__cplusplus)
  15 extern "C" {
  16 #endif
  17
  18 /*======  Dependency  ======*/
  19 #include <stddef.h>   /* size_t */
  20
  21
  22 /*======  Export for Windows  ======*/
  23 /*!
  24 *  ZSTDv07_DLL_EXPORT :
  25 *  Enable exporting of functions when building a Windows DLL
  26 */
  27 #if defined(_WIN32) && defined(ZSTDv07_DLL_EXPORT) && (ZSTDv07_DLL_EXPORT==1)
  28 #  define ZSTDLIBv07_API __declspec(dllexport)
  29 #else
  30 #  define ZSTDLIBv07_API
  31 #endif
  32
  33
  34 /* *************************************
  35 *  Simple API
  36 ***************************************/
  37 /*! ZSTDv07_getDecompressedSize() :
  38 *   @return : decompressed size if known, 0 otherwise.
  39        note 1 : if `0`, follow up with ZSTDv07_getFrameParams() to know precise failure cause.
  40        note 2 : decompressed size could be wrong or intentionally modified !
  41                 always ensure results fit within application's authorized limits */
  42 unsigned long long ZSTDv07_getDecompressedSize(const void* src, size_t srcSize);
  43
  44 /*! ZSTDv07_decompress() :
  45     `compressedSize` : must be _exact_ size of compressed input, otherwise decompression will fail.
  46     `dstCapacity` must be equal or larger than originalSize.
  47     @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
  48               or an errorCode if it fails (which can be tested using ZSTDv07_isError()) */
  49 ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity,
  50                                     const void* src, size_t compressedSize);
  51
  52 /**
  53 ZSTDv07_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.7.x format
  54     srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
  55     cSize (output parameter)  : the number of bytes that would be read to decompress this frame
  56                                 or an error code if it fails (which can be tested using ZSTDv01_isError())
  57     dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
  58                                 or ZSTD_CONTENTSIZE_ERROR if an error occurs
  59
  60     note : assumes `cSize` and `dBound` are _not_ NULL.
  61 */
  62 void ZSTDv07_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
  63                                      size_t* cSize, unsigned long long* dBound);
  64
  65 /*======  Helper functions  ======*/
  66 ZSTDLIBv07_API unsigned    ZSTDv07_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
  67 ZSTDLIBv07_API const char* ZSTDv07_getErrorName(size_t code);     /*!< provides readable string from an error code */
  68
  69
  70 /*-*************************************
  71 *  Explicit memory management
  72 ***************************************/
  73 /** Decompression context */
  74 typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx;
  75 ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void);
  76 ZSTDLIBv07_API size_t     ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx);      /*!< @return : errorCode */
  77
  78 /** ZSTDv07_decompressDCtx() :
  79 *   Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */
  80 ZSTDLIBv07_API size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
  81
  82
  83 /*-************************
  84 *  Simple dictionary API
  85 ***************************/
  86 /*! ZSTDv07_decompress_usingDict() :
  87 *   Decompression using a pre-defined Dictionary content (see dictBuilder).
  88 *   Dictionary must be identical to the one used during compression.
  89 *   Note : This function load the dictionary, resulting in a significant startup time */
  90 ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx* dctx,
  91                                                    void* dst, size_t dstCapacity,
  92                                              const void* src, size_t srcSize,
  93                                              const void* dict,size_t dictSize);
  94
  95
  96 /*-**************************
  97 *  Advanced Dictionary API
  98 ****************************/
  99 /*! ZSTDv07_createDDict() :
 100 *   Create a digested dictionary, ready to start decompression operation without startup delay.
 101 *   `dict` can be released after creation */
 102 typedef struct ZSTDv07_DDict_s ZSTDv07_DDict;
 103 ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize);
 104 ZSTDLIBv07_API size_t      ZSTDv07_freeDDict(ZSTDv07_DDict* ddict);
 105
 106 /*! ZSTDv07_decompress_usingDDict() :
 107 *   Decompression using a pre-digested Dictionary
 108 *   Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */
 109 ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx* dctx,
 110                                                     void* dst, size_t dstCapacity,
 111                                               const void* src, size_t srcSize,
 112                                               const ZSTDv07_DDict* ddict);
 113
 114 typedef struct {
 115     unsigned long long frameContentSize;
 116     unsigned windowSize;
 117     unsigned dictID;
 118     unsigned checksumFlag;
 119 } ZSTDv07_frameParams;
 120
 121 ZSTDLIBv07_API size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize);   /**< doesn't consume input */
 122
 123
 124
 125
 126 /* *************************************
 127 *  Streaming functions
 128 ***************************************/
 129 typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx;
 130 ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void);
 131 ZSTDLIBv07_API size_t      ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx);
 132
 133 ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx);
 134 ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize);
 135
 136 ZSTDLIBv07_API size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* dctx,
 137                                             void* dst, size_t* dstCapacityPtr,
 138                                       const void* src, size_t* srcSizePtr);
 139
 140 /*-***************************************************************************
 141 *  Streaming decompression howto
 142 *
 143 *  A ZBUFFv07_DCtx object is required to track streaming operations.
 144 *  Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources.
 145 *  Use ZBUFFv07_decompressInit() to start a new decompression operation,
 146 *   or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary.
 147 *  Note that ZBUFFv07_DCtx objects can be re-init multiple times.
 148 *
 149 *  Use ZBUFFv07_decompressContinue() repetitively to consume your input.
 150 *  *srcSizePtr and *dstCapacityPtr can be any size.
 151 *  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
 152 *  Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
 153 *  The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
 154 *  @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
 155 *            or 0 when a frame is completely decoded,
 156 *            or an error code, which can be tested using ZBUFFv07_isError().
 157 *
 158 *  Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize()
 159 *  output : ZBUFFv07_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
 160 *  input  : ZBUFFv07_recommendedDInSize == 128KB + 3;
 161 *           just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
 162 * *******************************************************************************/
 163
 164
 165 /* *************************************
 166 *  Tool functions
 167 ***************************************/
 168 ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode);
 169 ZSTDLIBv07_API const char* ZBUFFv07_getErrorName(size_t errorCode);
 170
 171 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
 172 *   These sizes are just hints, they tend to offer better latency */
 173 ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void);
 174 ZSTDLIBv07_API size_t ZBUFFv07_recommendedDOutSize(void);
 175
 176
 177 /*-*************************************
 178 *  Constants
 179 ***************************************/
 180 #define ZSTDv07_MAGICNUMBER            0xFD2FB527   /* v0.7 */
 181
 182
 183 #if defined (__cplusplus)
 184 }
 185 #endif
 186
 187 #endif  /* ZSTDv07_H_235446 */