AuroraMiddleware/zstd
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

updated doc (#269)

Browse Source
This commit is contained in:
Yann Collet 2016-08-01 02:26:20 +02:00
parent 917fe188f1
commit 3ca750372d
4 changed files with 19 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
NEWS
View File

@ -4,7 +4,7 @@ New : Build on FreeBSD and DragonFly, thanks to JrMarino
Changed : modified API : ZSTD_compressEnd()
Fixed : legacy mode with ZSTD_HEAPMODE=0, by Christopher Bergqvist
Fixed : premature end of frame when zero-sized raw block, reported by Eric Biggers
Fixed : statistics for large dictionaries (> 256 KB), reported by Ilona Papava
Fixed : large dictionaries (> 384 KB), reported by Ilona Papava
Fixed : checksum correctly checked in single-pass mode
Fixed : combined --test amd --rm, reported by Andreas M. Nilsson
Modified : minor compression level adaptations

BIN
images/Cspeed4.png
View File

Binary file not shown.
Side by Side Swipe Overlay

Before

Width:  |  Height:  |  Size: 46 KiB

After

Width:  |  Height:  |  Size: 34 KiB

2
lib/dictBuilder/zdict.c
View File

@ -879,7 +879,7 @@ size_t ZDICT_trainFromBuffer_unsafe(
U32 const dictListSize = MAX(MAX(DICTLISTSIZE, nbSamples), (U32)(maxDictSize/16));
dictItem* const dictList = (dictItem*)malloc(dictListSize * sizeof(*dictList));
unsigned const selectivity = params.selectivityLevel == 0 ? g_selectivity_default : params.selectivityLevel;
unsigned const minRep = (selectivity > 30) ? 1 : nbSamples >> selectivity;
unsigned const minRep = (selectivity > 30) ? MINRATIO : nbSamples >> selectivity;
size_t const targetDictSize = maxDictSize;
size_t const samplesBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
size_t dictSize = 0;

26
lib/zstd.h
View File

@ -79,20 +79,28 @@ ZSTDLIB_API size_t ZSTD_compress( void* dst, size_t dstCapacity,
int compressionLevel);
/*! ZSTD_getDecompressedSize() :
* @return : decompressed size if known, 0 otherwise.
* note 1 : decompressed size could be wrong or intentionally modified !
* Always ensure result fits within application's authorized limits !
* Each application can set its own limit, depending on local restrictions.
* For extended interoperability, it is recommended to support at least 8 MB.
* note 2 : when `0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more.
* note 3 : when `0`, and if no external guarantee about maximum possible decompressed size,
* it's necessary to use "streaming mode" to decompress data. */
* @return : decompressed size as a 64-bits value _if known_, 0 otherwise.
* note 1 : decompressed size can be very large (64-bits value),
* potentially larger than what local system can handle as a single memory segment.
* In which case, it's necessary to use streaming mode to decompress data.
* note 2 : decompressed size is an optional field, that may not be present.
* When `return==0`, consider data to decompress could have any size.
* In which case, it's necessary to use streaming mode to decompress data,
* or rely on application's implied limits.
* (For example, it may know that its own data is necessarily cut into blocks <= 16 KB).
* note 3 : decompressed size could be wrong or intentionally modified !
* Always ensure result fits within application's authorized limits !
* Each application can have its own set of conditions.
* If the intention is to decompress public data compressed by zstd command line utility,
* it is recommended to support at least 8 MB for extended compatibility.
* note 4 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. */
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
/*! ZSTD_decompress() :
`compressedSize` : must be the _exact_ size of compressed input, otherwise decompression will fail.
`dstCapacity` must be equal or larger than originalSize (see ZSTD_getDecompressedSize() ).
If maximum possible content size is unknown, use streaming mode to decompress data.
If originalSize is unknown, and if there is no implied application-specific limitations,
it's necessary to use streaming mode to decompress data.
@return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
or an errorCode if it fails (which can be tested using ZSTD_isError()) */
ZSTDLIB_API size_t ZSTD_decompress( void* dst, size_t dstCapacity,