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author | Yann Collet <cyan@fb.com> | 2019-04-11 15:19:48 -0700 |
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committer | Yann Collet <cyan@fb.com> | 2019-04-11 15:20:46 -0700 |
commit | bcb26565a732062759a2428e167e27ad3c2f6e96 (patch) | |
tree | 7b192662cba336b688b23ea04fcd6f48cbb3fc48 /doc | |
parent | 8d76c8a44a15cc7c0c1f345ba750e44edac7abb7 (diff) | |
download | lz4-bcb26565a732062759a2428e167e27ad3c2f6e96.tar.gz lz4-bcb26565a732062759a2428e167e27ad3c2f6e96.tar.bz2 lz4-bcb26565a732062759a2428e167e27ad3c2f6e96.zip |
improved documentation for LZ4 dictionary compression
Diffstat (limited to 'doc')
-rw-r--r-- | doc/lz4_manual.html | 11 | ||||
-rw-r--r-- | doc/lz4frame_manual.html | 2 |
2 files changed, 9 insertions, 4 deletions
diff --git a/doc/lz4_manual.html b/doc/lz4_manual.html index ef1a8b5..4cd21fc 100644 --- a/doc/lz4_manual.html +++ b/doc/lz4_manual.html @@ -180,10 +180,15 @@ int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int src </p></pre><BR> <pre><b>int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize); -</b><p> Use this function to load a static dictionary into LZ4_stream_t. - Any previous data will be forgotten, only 'dictionary' will remain in memory. +</b><p> Use this function to reference a static dictionary into LZ4_stream_t. + The dictionary must remain available during compression. + LZ4_loadDict() triggers a reset, so any previous data will be forgotten. + The same dictionary will have to be loaded on decompression side for successful decoding. + Dictionary are useful for better compression of small data (KB range). + While LZ4 accept any input as dictionary, + results are generally better when using Zstandard's Dictionary Builder. Loading a size of 0 is allowed, and is the same as reset. - @return : dictionary size, in bytes (necessarily <= 64 KB) + @return : loaded dictionary size, in bytes (necessarily <= 64 KB) </p></pre><BR> diff --git a/doc/lz4frame_manual.html b/doc/lz4frame_manual.html index d5496a1..914405f 100644 --- a/doc/lz4frame_manual.html +++ b/doc/lz4frame_manual.html @@ -343,7 +343,7 @@ LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx); <pre><b>LZ4FLIB_STATIC_API LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize); LZ4FLIB_STATIC_API void LZ4F_freeCDict(LZ4F_CDict* CDict); -</b><p> When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once. +</b><p> When compressing multiple messages / blocks using the same dictionary, it's recommended to load it just once. LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay. LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only. `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict |