zstd_v05.h 7.0 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 ZSTDv05_H
  11. #define ZSTDv05_H
  12. #if defined (__cplusplus)
  13. extern "C" {
  14. #endif
  15. /*-*************************************
  16. * Dependencies
  17. ***************************************/
  18. #include <stddef.h> /* size_t */
  19. #include "mem.h" /* U64, U32 */
  20. /* *************************************
  21. * Simple functions
  22. ***************************************/
  23. /*! ZSTDv05_decompress() :
  24. `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
  25. `dstCapacity` must be large enough, equal or larger than originalSize.
  26. @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
  27. or an errorCode if it fails (which can be tested using ZSTDv05_isError()) */
  28. size_t ZSTDv05_decompress( void* dst, size_t dstCapacity,
  29. const void* src, size_t compressedSize);
  30. /**
  31. ZSTDv05_getFrameSrcSize() : get the source length of a ZSTD frame
  32. compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
  33. return : the number of bytes that would be read to decompress this frame
  34. or an errorCode if it fails (which can be tested using ZSTDv05_isError())
  35. */
  36. size_t ZSTDv05_findFrameCompressedSize(const void* src, size_t compressedSize);
  37. /* *************************************
  38. * Helper functions
  39. ***************************************/
  40. /* Error Management */
  41. unsigned ZSTDv05_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
  42. const char* ZSTDv05_getErrorName(size_t code); /*!< provides readable string for an error code */
  43. /* *************************************
  44. * Explicit memory management
  45. ***************************************/
  46. /** Decompression context */
  47. typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx;
  48. ZSTDv05_DCtx* ZSTDv05_createDCtx(void);
  49. size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx); /*!< @return : errorCode */
  50. /** ZSTDv05_decompressDCtx() :
  51. * Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */
  52. size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
  53. /*-***********************
  54. * Simple Dictionary API
  55. *************************/
  56. /*! ZSTDv05_decompress_usingDict() :
  57. * Decompression using a pre-defined Dictionary content (see dictBuilder).
  58. * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
  59. * Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */
  60. size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx,
  61. void* dst, size_t dstCapacity,
  62. const void* src, size_t srcSize,
  63. const void* dict,size_t dictSize);
  64. /*-************************
  65. * Advanced Streaming API
  66. ***************************/
  67. typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy;
  68. typedef struct {
  69. U64 srcSize;
  70. U32 windowLog; /* the only useful information to retrieve */
  71. U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy;
  72. } ZSTDv05_parameters;
  73. size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize);
  74. size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize);
  75. void ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx);
  76. size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx);
  77. size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
  78. /*-***********************
  79. * ZBUFF API
  80. *************************/
  81. typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx;
  82. ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void);
  83. size_t ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx);
  84. size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx);
  85. size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize);
  86. size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx,
  87. void* dst, size_t* dstCapacityPtr,
  88. const void* src, size_t* srcSizePtr);
  89. /*-***************************************************************************
  90. * Streaming decompression
  91. *
  92. * A ZBUFFv05_DCtx object is required to track streaming operations.
  93. * Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources.
  94. * Use ZBUFFv05_decompressInit() to start a new decompression operation,
  95. * or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary.
  96. * Note that ZBUFFv05_DCtx objects can be reused multiple times.
  97. *
  98. * Use ZBUFFv05_decompressContinue() repetitively to consume your input.
  99. * *srcSizePtr and *dstCapacityPtr can be any size.
  100. * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
  101. * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
  102. * The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst.
  103. * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency)
  104. * or 0 when a frame is completely decoded
  105. * or an error code, which can be tested using ZBUFFv05_isError().
  106. *
  107. * Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize()
  108. * output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
  109. * input : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
  110. * *******************************************************************************/
  111. /* *************************************
  112. * Tool functions
  113. ***************************************/
  114. unsigned ZBUFFv05_isError(size_t errorCode);
  115. const char* ZBUFFv05_getErrorName(size_t errorCode);
  116. /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
  117. * These sizes are just hints, and tend to offer better latency */
  118. size_t ZBUFFv05_recommendedDInSize(void);
  119. size_t ZBUFFv05_recommendedDOutSize(void);
  120. /*-*************************************
  121. * Constants
  122. ***************************************/
  123. #define ZSTDv05_MAGICNUMBER 0xFD2FB525 /* v0.5 */
  124. #if defined (__cplusplus)
  125. }
  126. #endif
  127. #endif /* ZSTDv0505_H */