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-rw-r--r-- | NEWS | 8 | ||||
-rw-r--r-- | README.md | 48 |
2 files changed, 37 insertions, 19 deletions
@@ -1,14 +1,14 @@ r129: -New : LZ4 CLI improved performance when compressing/decompressing multiple files (#86, kind contribution from Kyle J. Harper & Takayuki Matsuoka) Added : LZ4_compress_fast() +Changed: New lz4 and lz4hc compression API. Previous function prototypes still supported. Changed: Sparse file support enabled by default -Changed: New function names LZ4_compress_safe() - Suggested by Evan Nemerson & Takayuki Matsuoka +New : LZ4 CLI improved performance compressing/decompressing multiple files (#86, kind contribution from Kyle J. Harper & Takayuki Matsuoka) Fixed : GCC 4.9+ optimization bug - Reported by Markus Trippelsdorf, Greg Slazinski & Evan Nemerson Changed: Enums converted to LZ4F_ namespace convention - by Takayuki Matsuoka Added : AppVeyor CI environment, for Visual tests - Suggested by Takayuki Matsuoka -Modified:Obsolete functions generate warnings - Suggested by Evan Nemerson & Takayuki Matsuoka +Modified:Obsolete functions generate warnings - Suggested by Evan Nemerson, contributed by Takayuki Matsuoka Fixed : Bug #75 (unfinished stream), reported by Yongwoon Cho -Updated: Documentation converted to MarkDown +Updated: Documentation converted to MarkDown format r128: New : lz4cli sparse file support (Requested by Neil Wilson, and contributed by Takayuki Matsuoka) @@ -8,8 +8,12 @@ It also features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limits on multi-core systems. -A high compression derivative, called LZ4_HC, is also provided. -It trades CPU time for compression ratio. +Speed can be tuned dynamically, selecting an "acceleration" factor +which trades compression ratio for more speed up. +On the other end, a high compression derivative, LZ4_HC, is also provided, +trading CPU time for improved compression ratio. +All versions feature the same excellent decompression speed. + |Branch |Status | |------------|---------| @@ -37,26 +41,40 @@ The reference system uses a Core i5-4300U @1.9GHz. Benchmark evaluates the compression of reference [Silesia Corpus] in single-thread mode. -| Compressor | Ratio | Compression | Decompression | -| ---------- | ----- | ----------- | ------------- | -| memcpy | 1.000 | 4200 MB/s | 4200 MB/s | -|**LZ4 fast (r129)**| 1.607 |**680 MB/s** | **2220 MB/s** | -|**LZ4 (r129)** |**2.101**|**385 MB/s** | **1850 MB/s** | -| LZO 2.06 | 2.108 | 350 MB/s | 510 MB/s | -| QuickLZ 1.5.1.b6 | 2.238 | 320 MB/s | 380 MB/s | -| Snappy 1.1.0 | 2.091 | 250 MB/s | 960 MB/s | -| zlib 1.2.8 -1 | 2.730 | 59 MB/s | 250 MB/s | -|**LZ4 HC (r129)** |**2.720**| 22 MB/s | **1830 MB/s** | -| zlib 1.2.8 -6 | 3.099 | 18 MB/s | 270 MB/s | +| Compressor | Ratio | Compression | Decompression | +| ---------- | ----- | ----------- | ------------- | +| memcpy | 1.000 | 4200 MB/s | 4200 MB/s | +|**LZ4 fast 17 (r129)**| 1.607 |**690 MB/s** | **2220 MB/s** | +|**LZ4 default (r129)**|**2.101**|**385 MB/s** | **1850 MB/s** | +| LZO 2.06 | 2.108 | 350 MB/s | 510 MB/s | +| QuickLZ 1.5.1.b6 | 2.238 | 320 MB/s | 380 MB/s | +| Snappy 1.1.0 | 2.091 | 250 MB/s | 960 MB/s | +| zlib 1.2.8 -1 | 2.730 | 59 MB/s | 250 MB/s | +|**LZ4 HC (r129)** |**2.720**| 22 MB/s | **1830 MB/s** | +| zlib 1.2.8 -6 | 3.099 | 18 MB/s | 270 MB/s | + + +Documentation +------------------------- The raw LZ4 block compression format is detailed within [lz4_Block_format]. -Compressing an arbitrarily long file or data stream requires multiple blocks. +To compress an arbitrarily long file or data stream, multiple blocks are required. Organizing these blocks and providing a common header format to handle their content is the purpose of the Frame format, defined into [lz4_Frame_format]. -Interoperable versions of LZ4 must respect this frame format too. +Interoperable versions of LZ4 must respect this frame format. + + +Other source versions +------------------------- + +Beyond the C reference source, +many contributors have created versions of lz4 in multiple languages. +A list of these sources is maintained on the [LZ4 Homepage]. + [Open-Source Benchmark program by m^2 (v0.14.3)]: http://encode.ru/threads/1371-Filesystem-benchmark?p=34029&viewfull=1#post34029 [Silesia Corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia [lz4_Block_format]: lz4_Block_format.md [lz4_Frame_format]: lz4_Frame_format.md +[LZ4 Homepage]: http://www.lz4.info |