2 * Copyright (c) Yann Collet, Meta Platforms, Inc. and affiliates.
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.
14 #if defined (__cplusplus)
18 /*-*************************************
20 ***************************************/
21 #include <stddef.h> /* size_t */
22 #include "../common/mem.h" /* U64, U32 */
25 /* *************************************
27 ***************************************/
28 /*! ZSTDv05_decompress() :
29 `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
30 `dstCapacity` must be large enough, equal or larger than originalSize.
31 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
32 or an errorCode if it fails (which can be tested using ZSTDv05_isError()) */
33 size_t ZSTDv05_decompress( void* dst, size_t dstCapacity,
34 const void* src, size_t compressedSize);
37 ZSTDv05_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.5.x format
38 srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
39 cSize (output parameter) : the number of bytes that would be read to decompress this frame
40 or an error code if it fails (which can be tested using ZSTDv01_isError())
41 dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
42 or ZSTD_CONTENTSIZE_ERROR if an error occurs
44 note : assumes `cSize` and `dBound` are _not_ NULL.
46 void ZSTDv05_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
47 size_t* cSize, unsigned long long* dBound);
49 /* *************************************
51 ***************************************/
52 /* Error Management */
53 unsigned ZSTDv05_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
54 const char* ZSTDv05_getErrorName(size_t code); /*!< provides readable string for an error code */
57 /* *************************************
58 * Explicit memory management
59 ***************************************/
60 /** Decompression context */
61 typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx;
62 ZSTDv05_DCtx* ZSTDv05_createDCtx(void);
63 size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx); /*!< @return : errorCode */
65 /** ZSTDv05_decompressDCtx() :
66 * Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */
67 size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
70 /*-***********************
71 * Simple Dictionary API
72 *************************/
73 /*! ZSTDv05_decompress_usingDict() :
74 * Decompression using a pre-defined Dictionary content (see dictBuilder).
75 * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
76 * Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */
77 size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx,
78 void* dst, size_t dstCapacity,
79 const void* src, size_t srcSize,
80 const void* dict,size_t dictSize);
82 /*-************************
83 * Advanced Streaming API
84 ***************************/
85 typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy;
88 U32 windowLog; /* the only useful information to retrieve */
89 U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy;
91 size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize);
93 size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize);
94 void ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx);
95 size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx);
96 size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
99 /*-***********************
101 *************************/
102 typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx;
103 ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void);
104 size_t ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx);
106 size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx);
107 size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize);
109 size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx,
110 void* dst, size_t* dstCapacityPtr,
111 const void* src, size_t* srcSizePtr);
113 /*-***************************************************************************
114 * Streaming decompression
116 * A ZBUFFv05_DCtx object is required to track streaming operations.
117 * Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources.
118 * Use ZBUFFv05_decompressInit() to start a new decompression operation,
119 * or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary.
120 * Note that ZBUFFv05_DCtx objects can be reused multiple times.
122 * Use ZBUFFv05_decompressContinue() repetitively to consume your input.
123 * *srcSizePtr and *dstCapacityPtr can be any size.
124 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
125 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
126 * The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst.
127 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency)
128 * or 0 when a frame is completely decoded
129 * or an error code, which can be tested using ZBUFFv05_isError().
131 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize()
132 * output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
133 * input : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
134 * *******************************************************************************/
137 /* *************************************
139 ***************************************/
140 unsigned ZBUFFv05_isError(size_t errorCode);
141 const char* ZBUFFv05_getErrorName(size_t errorCode);
143 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
144 * These sizes are just hints, and tend to offer better latency */
145 size_t ZBUFFv05_recommendedDInSize(void);
146 size_t ZBUFFv05_recommendedDOutSize(void);
150 /*-*************************************
152 ***************************************/
153 #define ZSTDv05_MAGICNUMBER 0xFD2FB525 /* v0.5 */
158 #if defined (__cplusplus)
162 #endif /* ZSTDv0505_H */