2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
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 "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_getFrameSrcSize() : get the source length of a ZSTD frame
38 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
39 return : the number of bytes that would be read to decompress this frame
40 or an errorCode if it fails (which can be tested using ZSTDv05_isError())
42 size_t ZSTDv05_findFrameCompressedSize(const void* src, size_t compressedSize);
44 /* *************************************
46 ***************************************/
47 /* Error Management */
48 unsigned ZSTDv05_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
49 const char* ZSTDv05_getErrorName(size_t code); /*!< provides readable string for an error code */
52 /* *************************************
53 * Explicit memory management
54 ***************************************/
55 /** Decompression context */
56 typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx;
57 ZSTDv05_DCtx* ZSTDv05_createDCtx(void);
58 size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx); /*!< @return : errorCode */
60 /** ZSTDv05_decompressDCtx() :
61 * Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */
62 size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
65 /*-***********************
66 * Simple Dictionary API
67 *************************/
68 /*! ZSTDv05_decompress_usingDict() :
69 * Decompression using a pre-defined Dictionary content (see dictBuilder).
70 * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
71 * Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */
72 size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx,
73 void* dst, size_t dstCapacity,
74 const void* src, size_t srcSize,
75 const void* dict,size_t dictSize);
77 /*-************************
78 * Advanced Streaming API
79 ***************************/
80 typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy;
83 U32 windowLog; /* the only useful information to retrieve */
84 U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy;
86 size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize);
88 size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize);
89 void ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx);
90 size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx);
91 size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
94 /*-***********************
96 *************************/
97 typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx;
98 ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void);
99 size_t ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx);
101 size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx);
102 size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize);
104 size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx,
105 void* dst, size_t* dstCapacityPtr,
106 const void* src, size_t* srcSizePtr);
108 /*-***************************************************************************
109 * Streaming decompression
111 * A ZBUFFv05_DCtx object is required to track streaming operations.
112 * Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources.
113 * Use ZBUFFv05_decompressInit() to start a new decompression operation,
114 * or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary.
115 * Note that ZBUFFv05_DCtx objects can be reused multiple times.
117 * Use ZBUFFv05_decompressContinue() repetitively to consume your input.
118 * *srcSizePtr and *dstCapacityPtr can be any size.
119 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
120 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
121 * The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst.
122 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency)
123 * or 0 when a frame is completely decoded
124 * or an error code, which can be tested using ZBUFFv05_isError().
126 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize()
127 * output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
128 * input : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
129 * *******************************************************************************/
132 /* *************************************
134 ***************************************/
135 unsigned ZBUFFv05_isError(size_t errorCode);
136 const char* ZBUFFv05_getErrorName(size_t errorCode);
138 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
139 * These sizes are just hints, and tend to offer better latency */
140 size_t ZBUFFv05_recommendedDInSize(void);
141 size_t ZBUFFv05_recommendedDOutSize(void);
145 /*-*************************************
147 ***************************************/
148 #define ZSTDv05_MAGICNUMBER 0xFD2FB525 /* v0.5 */
153 #if defined (__cplusplus)
157 #endif /* ZSTDv0505_H */