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author | Yann Collet <cyan@fb.com> | 2018-01-31 14:33:16 -0800 |
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committer | Yann Collet <cyan@fb.com> | 2018-01-31 14:33:16 -0800 |
commit | 87fb7a1d031a7e6df72d5ca50ab543a57ddca21f (patch) | |
tree | 4fb328b79a82c18cbb458e677681b80b40bb03d5 /doc | |
parent | 8258f4d9cba4c163f0c63a60a79d14d8aef90c4e (diff) | |
download | lz4-87fb7a1d031a7e6df72d5ca50ab543a57ddca21f.tar.gz lz4-87fb7a1d031a7e6df72d5ca50ab543a57ddca21f.tar.bz2 lz4-87fb7a1d031a7e6df72d5ca50ab543a57ddca21f.zip |
refactored frameCompress example
to better reflect LZ4F API usage.
Diffstat (limited to 'doc')
-rw-r--r-- | doc/lz4_manual.html | 4 | ||||
-rw-r--r-- | doc/lz4frame_manual.html | 44 |
2 files changed, 26 insertions, 22 deletions
diff --git a/doc/lz4_manual.html b/doc/lz4_manual.html index 6b7935d..46e6c3d 100644 --- a/doc/lz4_manual.html +++ b/doc/lz4_manual.html @@ -176,8 +176,8 @@ int LZ4_freeStream (LZ4_stream_t* streamPtr); If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster. Important : Up to 64KB of previously compressed data is assumed to remain present and unmodified in memory ! - Special 1 : If input buffer is a double-buffer, it can have any size, including < 64 KB. - Special 2 : If input buffer is a ring-buffer, it can have any size, including < 64 KB. + Special 1 : If input buffer is a double-buffer, it can have any size, including < 64 KB. + Special 2 : If input buffer is a ring-buffer, it can have any size, including < 64 KB. @return : size of compressed block or 0 if there is an error (typically, compressed data cannot fit into 'dst') diff --git a/doc/lz4frame_manual.html b/doc/lz4frame_manual.html index 590c632..1ddf6d8 100644 --- a/doc/lz4frame_manual.html +++ b/doc/lz4frame_manual.html @@ -101,8 +101,10 @@ <a name="Chapter5"></a><h2>Simple compression function</h2><pre></pre> <pre><b>size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr); -</b><p> Returns the maximum possible size of a frame compressed with LZ4F_compressFrame() given srcSize content and preferences. - Note : this result is only usable with LZ4F_compressFrame(), not with multi-segments compression. +</b><p> Returns the maximum possible compressed size with LZ4F_compressFrame() given srcSize and preferences. + `preferencesPtr` is optional. It can be replaced by NULL, in which case, the function will assume default preferences. + Note : this result is only usable with LZ4F_compressFrame(). + It may also be used with LZ4F_compressUpdate() _if no flush() operation_ is performed. </p></pre><BR> @@ -151,19 +153,21 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx); </p></pre><BR> <pre><b>size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr); -</b><p> Provides dstCapacity given a srcSize to guarantee operation success in worst case situations. - prefsPtr is optional : you can provide NULL as argument, preferences will be set to cover worst case scenario. - Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers. - When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations. +</b><p> Provides minimum dstCapacity for a given srcSize to guarantee operation success in worst case scenarios. + Estimation includes frame footer, which would be generated by LZ4F_compressEnd(). + Estimation doesn't include frame header, already generated by LZ4F_compressBegin(). + prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario. + Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers. + When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations. </p></pre><BR> <pre><b>size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr); -</b><p> LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary. - An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations. - This value is provided by LZ4F_compressBound(). - If this condition is not respected, LZ4F_compress() will fail (result is an errorCode). - LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized. +</b><p> LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary. + An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations. + This value is provided by LZ4F_compressBound(). + If this condition is not respected, LZ4F_compress() will fail (result is an errorCode). + LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized. `cOptPtr` is optional : NULL can be provided, in which case all options are set to default. @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered). or an error code if it fails (which can be tested using LZ4F_isError()) @@ -171,8 +175,8 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx); </p></pre><BR> <pre><b>size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr); -</b><p> When data must be generated and sent immediately, without waiting for a block to be completely filled, - it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx. +</b><p> When data must be generated and sent immediately, without waiting for a block to be completely filled, + it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx. `dstCapacity` must be large enough to ensure the operation will be successful. `cOptPtr` is optional : it's possible to provide NULL, all options will be set to default. @return : number of bytes written into dstBuffer (it can be zero, which means there was no data stored within cctx) @@ -200,13 +204,13 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx); </b></pre><BR> <pre><b>LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version); LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx); -</b><p> Create an LZ4F_dctx object, to track all decompression operations. - The version provided MUST be LZ4F_VERSION. - The function provides a pointer to an allocated and initialized LZ4F_dctx object. - The result is an errorCode, which can be tested using LZ4F_isError(). - dctx memory can be released using LZ4F_freeDecompressionContext(); - The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released. - That is, it should be == 0 if decompression has been completed fully and correctly. +</b><p> Create an LZ4F_dctx object, to track all decompression operations. + The version provided MUST be LZ4F_VERSION. + The function provides a pointer to an allocated and initialized LZ4F_dctx object. + The result is an errorCode, which can be tested using LZ4F_isError(). + dctx memory can be released using LZ4F_freeDecompressionContext(); + The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released. + That is, it should be == 0 if decompression has been completed fully and correctly. </p></pre><BR> |