ceph/src/zstd/lib/legacy/zstd_v05.h

   1 /**
   2  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the BSD-style license found in the
   6  * LICENSE file in the root directory of this source tree. An additional grant
   7  * of patent rights can be found in the PATENTS file in the same directory.
   8  */
   9
  10 #ifndef ZSTDv05_H
  11 #define ZSTDv05_H
  12
  13 #if defined (__cplusplus)
  14 extern "C" {
  15 #endif
  16
  17 /*-*************************************
  18 *  Dependencies
  19 ***************************************/
  20 #include <stddef.h>   /* size_t */
  21 #include "mem.h"      /* U64, U32 */
  22
  23
  24 /* *************************************
  25 *  Simple functions
  26 ***************************************/
  27 /*! ZSTDv05_decompress() :
  28     `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
  29     `dstCapacity` must be large enough, equal or larger than originalSize.
  30     @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
  31               or an errorCode if it fails (which can be tested using ZSTDv05_isError()) */
  32 size_t ZSTDv05_decompress( void* dst, size_t dstCapacity,
  33                      const void* src, size_t compressedSize);
  34
  35
  36 /* *************************************
  37 *  Helper functions
  38 ***************************************/
  39 /* Error Management */
  40 unsigned    ZSTDv05_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
  41 const char* ZSTDv05_getErrorName(size_t code);     /*!< provides readable string for an error code */
  42
  43
  44 /* *************************************
  45 *  Explicit memory management
  46 ***************************************/
  47 /** Decompression context */
  48 typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx;
  49 ZSTDv05_DCtx* ZSTDv05_createDCtx(void);
  50 size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx);      /*!< @return : errorCode */
  51
  52 /** ZSTDv05_decompressDCtx() :
  53 *   Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */
  54 size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
  55
  56
  57 /*-***********************
  58 *  Simple Dictionary API
  59 *************************/
  60 /*! ZSTDv05_decompress_usingDict() :
  61 *   Decompression using a pre-defined Dictionary content (see dictBuilder).
  62 *   Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
  63 *   Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */
  64 size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx,
  65                                             void* dst, size_t dstCapacity,
  66                                       const void* src, size_t srcSize,
  67                                       const void* dict,size_t dictSize);
  68
  69 /*-************************
  70 *  Advanced Streaming API
  71 ***************************/
  72 typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy;
  73 typedef struct {
  74     U64 srcSize;
  75     U32 windowLog;     /* the only useful information to retrieve */
  76     U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy;
  77 } ZSTDv05_parameters;
  78 size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize);
  79
  80 size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize);
  81 void   ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx);
  82 size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx);
  83 size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
  84
  85
  86 /*-***********************
  87 *  ZBUFF API
  88 *************************/
  89 typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx;
  90 ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void);
  91 size_t         ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx);
  92
  93 size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx);
  94 size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize);
  95
  96 size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx,
  97                                             void* dst, size_t* dstCapacityPtr,
  98                                       const void* src, size_t* srcSizePtr);
  99
 100 /*-***************************************************************************
 101 *  Streaming decompression
 102 *
 103 *  A ZBUFFv05_DCtx object is required to track streaming operations.
 104 *  Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources.
 105 *  Use ZBUFFv05_decompressInit() to start a new decompression operation,
 106 *   or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary.
 107 *  Note that ZBUFFv05_DCtx objects can be reused multiple times.
 108 *
 109 *  Use ZBUFFv05_decompressContinue() repetitively to consume your input.
 110 *  *srcSizePtr and *dstCapacityPtr can be any size.
 111 *  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
 112 *  Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
 113 *  The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst.
 114 *  @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency)
 115 *            or 0 when a frame is completely decoded
 116 *            or an error code, which can be tested using ZBUFFv05_isError().
 117 *
 118 *  Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize()
 119 *  output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
 120 *  input  : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
 121 * *******************************************************************************/
 122
 123
 124 /* *************************************
 125 *  Tool functions
 126 ***************************************/
 127 unsigned ZBUFFv05_isError(size_t errorCode);
 128 const char* ZBUFFv05_getErrorName(size_t errorCode);
 129
 130 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
 131 *   These sizes are just hints, and tend to offer better latency */
 132 size_t ZBUFFv05_recommendedDInSize(void);
 133 size_t ZBUFFv05_recommendedDOutSize(void);
 134
 135
 136
 137 /*-*************************************
 138 *  Constants
 139 ***************************************/
 140 #define ZSTDv05_MAGICNUMBER 0xFD2FB525   /* v0.5 */
 141
 142
 143
 144
 145 #if defined (__cplusplus)
 146 }
 147 #endif
 148
 149 #endif  /* ZSTDv0505_H */