zstd_v06.h 7.5 KB

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  1. /*
  2. * Copyright (c) 2016-present, 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. #ifndef ZSTDv06_H
  11. #define ZSTDv06_H
  12. #if defined (__cplusplus)
  13. extern "C" {
  14. #endif
  15. /*====== Dependency ======*/
  16. #include <stddef.h> /* size_t */
  17. /*====== Export for Windows ======*/
  18. /*!
  19. * ZSTDv06_DLL_EXPORT :
  20. * Enable exporting of functions when building a Windows DLL
  21. */
  22. #if defined(_WIN32) && defined(ZSTDv06_DLL_EXPORT) && (ZSTDv06_DLL_EXPORT==1)
  23. # define ZSTDLIBv06_API __declspec(dllexport)
  24. #else
  25. # define ZSTDLIBv06_API
  26. #endif
  27. /* *************************************
  28. * Simple functions
  29. ***************************************/
  30. /*! ZSTDv06_decompress() :
  31. `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
  32. `dstCapacity` must be large enough, equal or larger than originalSize.
  33. @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
  34. or an errorCode if it fails (which can be tested using ZSTDv06_isError()) */
  35. ZSTDLIBv06_API size_t ZSTDv06_decompress( void* dst, size_t dstCapacity,
  36. const void* src, size_t compressedSize);
  37. /**
  38. ZSTDv06_getFrameSrcSize() : get the source length of a ZSTD frame
  39. compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
  40. return : the number of bytes that would be read to decompress this frame
  41. or an errorCode if it fails (which can be tested using ZSTDv06_isError())
  42. */
  43. size_t ZSTDv06_findFrameCompressedSize(const void* src, size_t compressedSize);
  44. /* *************************************
  45. * Helper functions
  46. ***************************************/
  47. ZSTDLIBv06_API size_t ZSTDv06_compressBound(size_t srcSize); /*!< maximum compressed size (worst case scenario) */
  48. /* Error Management */
  49. ZSTDLIBv06_API unsigned ZSTDv06_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
  50. ZSTDLIBv06_API const char* ZSTDv06_getErrorName(size_t code); /*!< provides readable string for an error code */
  51. /* *************************************
  52. * Explicit memory management
  53. ***************************************/
  54. /** Decompression context */
  55. typedef struct ZSTDv06_DCtx_s ZSTDv06_DCtx;
  56. ZSTDLIBv06_API ZSTDv06_DCtx* ZSTDv06_createDCtx(void);
  57. ZSTDLIBv06_API size_t ZSTDv06_freeDCtx(ZSTDv06_DCtx* dctx); /*!< @return : errorCode */
  58. /** ZSTDv06_decompressDCtx() :
  59. * Same as ZSTDv06_decompress(), but requires an already allocated ZSTDv06_DCtx (see ZSTDv06_createDCtx()) */
  60. ZSTDLIBv06_API size_t ZSTDv06_decompressDCtx(ZSTDv06_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
  61. /*-***********************
  62. * Dictionary API
  63. *************************/
  64. /*! ZSTDv06_decompress_usingDict() :
  65. * Decompression using a pre-defined Dictionary content (see dictBuilder).
  66. * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
  67. * Note : dict can be NULL, in which case, it's equivalent to ZSTDv06_decompressDCtx() */
  68. ZSTDLIBv06_API size_t ZSTDv06_decompress_usingDict(ZSTDv06_DCtx* dctx,
  69. void* dst, size_t dstCapacity,
  70. const void* src, size_t srcSize,
  71. const void* dict,size_t dictSize);
  72. /*-************************
  73. * Advanced Streaming API
  74. ***************************/
  75. struct ZSTDv06_frameParams_s { unsigned long long frameContentSize; unsigned windowLog; };
  76. typedef struct ZSTDv06_frameParams_s ZSTDv06_frameParams;
  77. ZSTDLIBv06_API size_t ZSTDv06_getFrameParams(ZSTDv06_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
  78. ZSTDLIBv06_API size_t ZSTDv06_decompressBegin_usingDict(ZSTDv06_DCtx* dctx, const void* dict, size_t dictSize);
  79. ZSTDLIBv06_API void ZSTDv06_copyDCtx(ZSTDv06_DCtx* dctx, const ZSTDv06_DCtx* preparedDCtx);
  80. ZSTDLIBv06_API size_t ZSTDv06_nextSrcSizeToDecompress(ZSTDv06_DCtx* dctx);
  81. ZSTDLIBv06_API size_t ZSTDv06_decompressContinue(ZSTDv06_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
  82. /* *************************************
  83. * ZBUFF API
  84. ***************************************/
  85. typedef struct ZBUFFv06_DCtx_s ZBUFFv06_DCtx;
  86. ZSTDLIBv06_API ZBUFFv06_DCtx* ZBUFFv06_createDCtx(void);
  87. ZSTDLIBv06_API size_t ZBUFFv06_freeDCtx(ZBUFFv06_DCtx* dctx);
  88. ZSTDLIBv06_API size_t ZBUFFv06_decompressInit(ZBUFFv06_DCtx* dctx);
  89. ZSTDLIBv06_API size_t ZBUFFv06_decompressInitDictionary(ZBUFFv06_DCtx* dctx, const void* dict, size_t dictSize);
  90. ZSTDLIBv06_API size_t ZBUFFv06_decompressContinue(ZBUFFv06_DCtx* dctx,
  91. void* dst, size_t* dstCapacityPtr,
  92. const void* src, size_t* srcSizePtr);
  93. /*-***************************************************************************
  94. * Streaming decompression howto
  95. *
  96. * A ZBUFFv06_DCtx object is required to track streaming operations.
  97. * Use ZBUFFv06_createDCtx() and ZBUFFv06_freeDCtx() to create/release resources.
  98. * Use ZBUFFv06_decompressInit() to start a new decompression operation,
  99. * or ZBUFFv06_decompressInitDictionary() if decompression requires a dictionary.
  100. * Note that ZBUFFv06_DCtx objects can be re-init multiple times.
  101. *
  102. * Use ZBUFFv06_decompressContinue() repetitively to consume your input.
  103. * *srcSizePtr and *dstCapacityPtr can be any size.
  104. * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
  105. * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
  106. * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
  107. * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
  108. * or 0 when a frame is completely decoded,
  109. * or an error code, which can be tested using ZBUFFv06_isError().
  110. *
  111. * Hint : recommended buffer sizes (not compulsory) : ZBUFFv06_recommendedDInSize() and ZBUFFv06_recommendedDOutSize()
  112. * output : ZBUFFv06_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
  113. * input : ZBUFFv06_recommendedDInSize == 128KB + 3;
  114. * just follow indications from ZBUFFv06_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
  115. * *******************************************************************************/
  116. /* *************************************
  117. * Tool functions
  118. ***************************************/
  119. ZSTDLIBv06_API unsigned ZBUFFv06_isError(size_t errorCode);
  120. ZSTDLIBv06_API const char* ZBUFFv06_getErrorName(size_t errorCode);
  121. /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
  122. * These sizes are just hints, they tend to offer better latency */
  123. ZSTDLIBv06_API size_t ZBUFFv06_recommendedDInSize(void);
  124. ZSTDLIBv06_API size_t ZBUFFv06_recommendedDOutSize(void);
  125. /*-*************************************
  126. * Constants
  127. ***************************************/
  128. #define ZSTDv06_MAGICNUMBER 0xFD2FB526 /* v0.6 */
  129. #if defined (__cplusplus)
  130. }
  131. #endif
  132. #endif /* ZSTDv06_BUFFERED_H */