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diff --git a/doc/zstd_manual.html b/doc/zstd_manual.html index f1628b50d08d3..f281120060c36 100644 --- a/doc/zstd_manual.html +++ b/doc/zstd_manual.html @@ -1,46 +1,36 @@ <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> -<title>zstd 1.4.0 Manual</title> +<title>zstd 1.4.1 Manual</title> </head> <body> -<h1>zstd 1.4.0 Manual</h1> +<h1>zstd 1.4.1 Manual</h1> <hr> <a name="Contents"></a><h2>Contents</h2> <ol> <li><a href="#Chapter1">Introduction</a></li> <li><a href="#Chapter2">Version</a></li> -<li><a href="#Chapter3">Default constant</a></li> -<li><a href="#Chapter4">Constants</a></li> -<li><a href="#Chapter5">Simple API</a></li> -<li><a href="#Chapter6">Explicit context</a></li> -<li><a href="#Chapter7">Advanced compression API</a></li> -<li><a href="#Chapter8">Advanced decompression API</a></li> -<li><a href="#Chapter9">Streaming</a></li> -<li><a href="#Chapter10">Streaming compression - HowTo</a></li> -<li><a href="#Chapter11">This is a legacy streaming API, and can be replaced by ZSTD_CCtx_reset() and</a></li> -<li><a href="#Chapter12">Equivalent to:</a></li> -<li><a href="#Chapter13">Alternative for ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue).</a></li> -<li><a href="#Chapter14">Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_flush).</a></li> -<li><a href="#Chapter15">Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_end).</a></li> -<li><a href="#Chapter16">Streaming decompression - HowTo</a></li> -<li><a href="#Chapter17">Simple dictionary API</a></li> -<li><a href="#Chapter18">Bulk processing dictionary API</a></li> -<li><a href="#Chapter19">Dictionary helper functions</a></li> -<li><a href="#Chapter20">Advanced dictionary and prefix API</a></li> -<li><a href="#Chapter21">ADVANCED AND EXPERIMENTAL FUNCTIONS</a></li> -<li><a href="#Chapter22">experimental API (static linking only)</a></li> -<li><a href="#Chapter23">Frame size functions</a></li> -<li><a href="#Chapter24">ZSTD_decompressBound() :</a></li> -<li><a href="#Chapter25">Memory management</a></li> -<li><a href="#Chapter26">Advanced compression functions</a></li> -<li><a href="#Chapter27">Advanced decompression functions</a></li> -<li><a href="#Chapter28">Advanced streaming functions</a></li> -<li><a href="#Chapter29">Buffer-less and synchronous inner streaming functions</a></li> -<li><a href="#Chapter30">Buffer-less streaming compression (synchronous mode)</a></li> -<li><a href="#Chapter31">Buffer-less streaming decompression (synchronous mode)</a></li> -<li><a href="#Chapter32">ZSTD_getFrameHeader() :</a></li> -<li><a href="#Chapter33">Block level API</a></li> +<li><a href="#Chapter3">Simple API</a></li> +<li><a href="#Chapter4">Explicit context</a></li> +<li><a href="#Chapter5">Advanced compression API</a></li> +<li><a href="#Chapter6">Advanced decompression API</a></li> +<li><a href="#Chapter7">Streaming</a></li> +<li><a href="#Chapter8">Streaming compression - HowTo</a></li> +<li><a href="#Chapter9">Streaming decompression - HowTo</a></li> +<li><a href="#Chapter10">Simple dictionary API</a></li> +<li><a href="#Chapter11">Bulk processing dictionary API</a></li> +<li><a href="#Chapter12">Dictionary helper functions</a></li> +<li><a href="#Chapter13">Advanced dictionary and prefix API</a></li> +<li><a href="#Chapter14">experimental API (static linking only)</a></li> +<li><a href="#Chapter15">Frame size functions</a></li> +<li><a href="#Chapter16">Memory management</a></li> +<li><a href="#Chapter17">Advanced compression functions</a></li> +<li><a href="#Chapter18">Advanced decompression functions</a></li> +<li><a href="#Chapter19">Advanced streaming functions</a></li> +<li><a href="#Chapter20">Buffer-less and synchronous inner streaming functions</a></li> +<li><a href="#Chapter21">Buffer-less streaming compression (synchronous mode)</a></li> +<li><a href="#Chapter22">Buffer-less streaming decompression (synchronous mode)</a></li> +<li><a href="#Chapter23">Block level API</a></li> </ol> <hr> <a name="Chapter1"></a><h2>Introduction</h2><pre> @@ -78,11 +68,7 @@ <pre><b>unsigned ZSTD_versionNumber(void); </b>/**< to check runtime library version */<b> </b></pre><BR> -<a name="Chapter3"></a><h2>Default constant</h2><pre></pre> - -<a name="Chapter4"></a><h2>Constants</h2><pre></pre> - -<a name="Chapter5"></a><h2>Simple API</h2><pre></pre> +<a name="Chapter3"></a><h2>Simple API</h2><pre></pre> <pre><b>size_t ZSTD_compress( void* dst, size_t dstCapacity, const void* src, size_t srcSize, @@ -152,12 +138,17 @@ const char* ZSTD_getErrorName(size_t code); </b>/*!< provides readable strin int ZSTD_minCLevel(void); </b>/*!< minimum negative compression level allowed */<b> int ZSTD_maxCLevel(void); </b>/*!< maximum compression level available */<b> </pre></b><BR> -<a name="Chapter6"></a><h2>Explicit context</h2><pre></pre> +<a name="Chapter4"></a><h2>Explicit context</h2><pre></pre> <h3>Compression context</h3><pre> When compressing many times, - it is recommended to allocate a context just once, and re-use it for each successive compression operation. + it is recommended to allocate a context just once, + and re-use it for each successive compression operation. This will make workload friendlier for system's memory. - Use one context per thread for parallel execution in multi-threaded environments. + Note : re-using context is just a speed / resource optimization. + It doesn't change the compression ratio, which remains identical. + Note 2 : In multi-threaded environments, + use one different context per thread for parallel execution. + </pre><b><pre>typedef struct ZSTD_CCtx_s ZSTD_CCtx; ZSTD_CCtx* ZSTD_createCCtx(void); size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx); @@ -189,7 +180,7 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); </p></pre><BR> -<a name="Chapter7"></a><h2>Advanced compression API</h2><pre></pre> +<a name="Chapter5"></a><h2>Advanced compression API</h2><pre></pre> <pre><b>typedef enum { ZSTD_fast=1, ZSTD_dfast=2, @@ -332,6 +323,7 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); * ZSTD_c_forceMaxWindow * ZSTD_c_forceAttachDict * ZSTD_c_literalCompressionMode + * ZSTD_c_targetCBlockSize * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them. * note : never ever use experimentalParam? names directly; * also, the enums values themselves are unstable and can still change. @@ -341,6 +333,7 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); ZSTD_c_experimentalParam3=1000, ZSTD_c_experimentalParam4=1001, ZSTD_c_experimentalParam5=1002, + ZSTD_c_experimentalParam6=1003, } ZSTD_cParameter; </b></pre><BR> <pre><b>typedef struct { @@ -424,7 +417,7 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); </p></pre><BR> -<a name="Chapter8"></a><h2>Advanced decompression API</h2><pre></pre> +<a name="Chapter6"></a><h2>Advanced decompression API</h2><pre></pre> <pre><b>typedef enum { @@ -472,7 +465,7 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); </p></pre><BR> -<a name="Chapter9"></a><h2>Streaming</h2><pre></pre> +<a name="Chapter7"></a><h2>Streaming</h2><pre></pre> <pre><b>typedef struct ZSTD_inBuffer_s { const void* src; </b>/**< start of input buffer */<b> @@ -486,7 +479,7 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx); size_t pos; </b>/**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */<b> } ZSTD_outBuffer; </b></pre><BR> -<a name="Chapter10"></a><h2>Streaming compression - HowTo</h2><pre> +<a name="Chapter8"></a><h2>Streaming compression - HowTo</h2><pre> A ZSTD_CStream object is required to track streaming operation. Use ZSTD_createCStream() and ZSTD_freeCStream() to create/release resources. ZSTD_CStream objects can be reused multiple times on consecutive compression operations. @@ -592,31 +585,28 @@ size_t ZSTD_freeCStream(ZSTD_CStream* zcs); <pre><b>size_t ZSTD_CStreamInSize(void); </b>/**< recommended size for input buffer */<b> </b></pre><BR> -<pre><b>size_t ZSTD_CStreamOutSize(void); </b>/**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block in all circumstances. */<b> +<pre><b>size_t ZSTD_CStreamOutSize(void); </b>/**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block. */<b> </b></pre><BR> -<a name="Chapter11"></a><h2>This is a legacy streaming API, and can be replaced by ZSTD_CCtx_reset() and</h2><pre> ZSTD_compressStream2(). It is redundent, but is still fully supported. - Advanced parameters and dictionary compression can only be used through the - new API. -<BR></pre> - -<a name="Chapter12"></a><h2>Equivalent to:</h2><pre> +<pre><b>size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel); +</b>/*!<b> + * Alternative for ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue). + * NOTE: The return value is different. ZSTD_compressStream() returns a hint for + * the next read size (if non-zero and not an error). ZSTD_compressStream2() + * returns the minimum nb of bytes left to flush (if non-zero and not an error). + */ +size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input); +</b>/*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_flush). */<b> +size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output); +</b>/*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_end). */<b> +size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output); +</b><p> ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only); ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any) ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel); -<BR></pre> - -<a name="Chapter13"></a><h2>Alternative for ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue).</h2><pre> NOTE: The return value is different. ZSTD_compressStream() returns a hint for - the next read size (if non-zero and not an error). ZSTD_compressStream2() - returns the number of bytes left to flush (if non-zero and not an error). - -<BR></pre> - -<a name="Chapter14"></a><h2>Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_flush).</h2><pre></pre> - -<a name="Chapter15"></a><h2>Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_end).</h2><pre></pre> +</p></pre><BR> -<a name="Chapter16"></a><h2>Streaming decompression - HowTo</h2><pre> +<a name="Chapter9"></a><h2>Streaming decompression - HowTo</h2><pre> A ZSTD_DStream object is required to track streaming operations. Use ZSTD_createDStream() and ZSTD_freeDStream() to create/release resources. ZSTD_DStream objects can be re-used multiple times. @@ -647,14 +637,12 @@ size_t ZSTD_freeCStream(ZSTD_CStream* zcs); <h3>ZSTD_DStream management functions</h3><pre></pre><b><pre>ZSTD_DStream* ZSTD_createDStream(void); size_t ZSTD_freeDStream(ZSTD_DStream* zds); </pre></b><BR> -<h3>Streaming decompression functions</h3><pre></pre><b><pre>size_t ZSTD_initDStream(ZSTD_DStream* zds); -size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input); -</pre></b><BR> +<h3>Streaming decompression functions</h3><pre></pre><b><pre></pre></b><BR> <pre><b>size_t ZSTD_DStreamInSize(void); </b>/*!< recommended size for input buffer */<b> </b></pre><BR> <pre><b>size_t ZSTD_DStreamOutSize(void); </b>/*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */<b> </b></pre><BR> -<a name="Chapter17"></a><h2>Simple dictionary API</h2><pre></pre> +<a name="Chapter10"></a><h2>Simple dictionary API</h2><pre></pre> <pre><b>size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx, void* dst, size_t dstCapacity, @@ -680,7 +668,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB Note : When `dict == NULL || dictSize < 8` no dictionary is used. </p></pre><BR> -<a name="Chapter18"></a><h2>Bulk processing dictionary API</h2><pre></pre> +<a name="Chapter11"></a><h2>Bulk processing dictionary API</h2><pre></pre> <pre><b>ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize, int compressionLevel); @@ -723,7 +711,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB Recommended when same dictionary is used multiple times. </p></pre><BR> -<a name="Chapter19"></a><h2>Dictionary helper functions</h2><pre></pre> +<a name="Chapter12"></a><h2>Dictionary helper functions</h2><pre></pre> <pre><b>unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize); </b><p> Provides the dictID stored within dictionary. @@ -749,7 +737,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. </p></pre><BR> -<a name="Chapter20"></a><h2>Advanced dictionary and prefix API</h2><pre> +<a name="Chapter13"></a><h2>Advanced dictionary and prefix API</h2><pre> This API allows dictionaries to be used with ZSTD_compress2(), ZSTD_compressStream2(), and ZSTD_decompress(). Dictionaries are sticky, and only reset with the context is reset with ZSTD_reset_parameters or @@ -867,15 +855,7 @@ size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict); Note that object memory usage can evolve (increase or decrease) over time. </p></pre><BR> -<a name="Chapter21"></a><h2>ADVANCED AND EXPERIMENTAL FUNCTIONS</h2><pre> - The definitions in the following section are considered experimental. - They are provided for advanced scenarios. - They should never be used with a dynamic library, as prototypes may change in the future. - Use them only in association with static linking. - -<BR></pre> - -<a name="Chapter22"></a><h2>experimental API (static linking only)</h2><pre> +<a name="Chapter14"></a><h2>experimental API (static linking only)</h2><pre> The following symbols and constants are not planned to join "stable API" status in the near future. They can still change in future versions. @@ -973,7 +953,7 @@ size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict); ZSTD_lcm_uncompressed = 2, </b>/**< Always emit uncompressed literals. */<b> } ZSTD_literalCompressionMode_e; </b></pre><BR> -<a name="Chapter23"></a><h2>Frame size functions</h2><pre></pre> +<a name="Chapter15"></a><h2>Frame size functions</h2><pre></pre> <pre><b>unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize); </b><p> `src` should point to the start of a series of ZSTD encoded and/or skippable frames @@ -998,7 +978,8 @@ size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict); however it does mean that all frame data must be present and valid. </p></pre><BR> -<a name="Chapter24"></a><h2>ZSTD_decompressBound() :</h2><pre> `src` should point to the start of a series of ZSTD encoded and/or skippable frames +<pre><b>unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize); +</b><p> `src` should point to the start of a series of ZSTD encoded and/or skippable frames `srcSize` must be the _exact_ size of this series (i.e. there should be a frame boundary at `src + srcSize`) @return : - upper-bound for the decompressed size of all data in all successive frames @@ -1010,7 +991,7 @@ size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict); note 3 : when the decompressed size field isn't available, the upper-bound for that frame is calculated by: upper-bound = # blocks * min(128 KB, Window_Size) -<BR></pre> +</p></pre><BR> <pre><b>size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize); </b><p> srcSize must be >= ZSTD_FRAMEHEADERSIZE_PREFIX. @@ -1018,7 +999,7 @@ size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict); or an error code (if srcSize is too small) </p></pre><BR> -<a name="Chapter25"></a><h2>Memory management</h2><pre></pre> +<a name="Chapter16"></a><h2>Memory management</h2><pre></pre> <pre><b>size_t ZSTD_estimateCCtxSize(int compressionLevel); size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams); @@ -1098,7 +1079,7 @@ static ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL }; </b>/**< t </p></pre><BR> -<a name="Chapter26"></a><h2>Advanced compression functions</h2><pre></pre> +<a name="Chapter17"></a><h2>Advanced compression functions</h2><pre></pre> <pre><b>ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel); </b><p> Create a digested dictionary for compression @@ -1243,7 +1224,7 @@ size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params); </p></pre><BR> -<a name="Chapter27"></a><h2>Advanced decompression functions</h2><pre></pre> +<a name="Chapter18"></a><h2>Advanced decompression functions</h2><pre></pre> <pre><b>unsigned ZSTD_isFrame(const void* buffer, size_t size); </b><p> Tells if the content of `buffer` starts with a valid Frame Identifier. @@ -1305,7 +1286,7 @@ size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params); </p></pre><BR> -<a name="Chapter28"></a><h2>Advanced streaming functions</h2><pre> Warning : most of these functions are now redundant with the Advanced API. +<a name="Chapter19"></a><h2>Advanced streaming functions</h2><pre> Warning : most of these functions are now redundant with the Advanced API. Once Advanced API reaches "stable" status, redundant functions will be deprecated, and then at some point removed. <BR></pre> @@ -1407,18 +1388,41 @@ size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, const ZSTD_CDict* </p></pre><BR> -<h3>Advanced Streaming decompression functions</h3><pre></pre><b><pre>size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); </b>/**< note: no dictionary will be used if dict == NULL or dictSize < 8 */<b> -size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict); </b>/**< note : ddict is referenced, it must outlive decompression session */<b> -size_t ZSTD_resetDStream(ZSTD_DStream* zds); </b>/**< re-use decompression parameters from previous init; saves dictionary loading */<b> +<h3>Advanced Streaming decompression functions</h3><pre></pre><b><pre></b>/**<b> + * This function is deprecated, and is equivalent to: + * + * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only); + * ZSTD_DCtx_loadDictionary(zds, dict, dictSize); + * + * note: no dictionary will be used if dict == NULL or dictSize < 8 + */ +size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); +</b>/**<b> + * This function is deprecated, and is equivalent to: + * + * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only); + * ZSTD_DCtx_refDDict(zds, ddict); + * + * note : ddict is referenced, it must outlive decompression session + */ +size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict); +</b>/**<b> + * This function is deprecated, and is equivalent to: + * + * ZSTD_DCtx_reset(zds, ZSTD_reset_session_only); + * + * re-use decompression parameters from previous init; saves dictionary loading + */ +size_t ZSTD_resetDStream(ZSTD_DStream* zds); </pre></b><BR> -<a name="Chapter29"></a><h2>Buffer-less and synchronous inner streaming functions</h2><pre> +<a name="Chapter20"></a><h2>Buffer-less and synchronous inner streaming functions</h2><pre> This is an advanced API, giving full control over buffer management, for users which need direct control over memory. But it's also a complex one, with several restrictions, documented below. Prefer normal streaming API for an easier experience. <BR></pre> -<a name="Chapter30"></a><h2>Buffer-less streaming compression (synchronous mode)</h2><pre> +<a name="Chapter21"></a><h2>Buffer-less streaming compression (synchronous mode)</h2><pre> A ZSTD_CCtx object is required to track streaming operations. Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage resource. ZSTD_CCtx object can be re-used multiple times within successive compression operations. @@ -1454,7 +1458,7 @@ size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict); size_t ZSTD_compressBegin_usingCDict_advanced(ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict, ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize); </b>/* compression parameters are already set within cdict. pledgedSrcSize must be correct. If srcSize is not known, use macro ZSTD_CONTENTSIZE_UNKNOWN */<b> size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); </b>/**< note: if pledgedSrcSize is not known, use ZSTD_CONTENTSIZE_UNKNOWN */<b> </pre></b><BR> -<a name="Chapter31"></a><h2>Buffer-less streaming decompression (synchronous mode)</h2><pre> +<a name="Chapter22"></a><h2>Buffer-less streaming decompression (synchronous mode)</h2><pre> A ZSTD_DCtx object is required to track streaming operations. Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it. A ZSTD_DCtx object can be re-used multiple times. @@ -1536,23 +1540,21 @@ typedef struct { unsigned checksumFlag; } ZSTD_frameHeader; </pre></b><BR> -<a name="Chapter32"></a><h2>ZSTD_getFrameHeader() :</h2><pre> decode Frame Header, or requires larger `srcSize`. +<pre><b>size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize); </b>/**< doesn't consume input */<b> +</b>/*! ZSTD_getFrameHeader_advanced() :<b> + * same as ZSTD_getFrameHeader(), + * with added capability to select a format (like ZSTD_f_zstd1_magicless) */ +size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format); +size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize); </b>/**< when frame content size is not known, pass in frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN */<b> +</b><p> decode Frame Header, or requires larger `srcSize`. @return : 0, `zfhPtr` is correctly filled, >0, `srcSize` is too small, value is wanted `srcSize` amount, or an error code, which can be tested using ZSTD_isError() -<BR></pre> - -<pre><b>size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize); </b>/**< doesn't consume input */<b> -</b></pre><BR> -<pre><b>size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format); -size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize); </b>/**< when frame content size is not known, pass in frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN */<b> -</b><p> same as ZSTD_getFrameHeader(), - with added capability to select a format (like ZSTD_f_zstd1_magicless) </p></pre><BR> <pre><b>typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e; </b></pre><BR> -<a name="Chapter33"></a><h2>Block level API</h2><pre></pre> +<a name="Chapter23"></a><h2>Block level API</h2><pre></pre> <pre><b></b><p> Frame metadata cost is typically ~18 bytes, which can be non-negligible for very small blocks (< 100 bytes). User will have to take in charge required information to regenerate data, such as compressed and content sizes. |