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src.rivoreo.one / lz4 / 9517bd9234f1a8978490b04719e6b704fb8e3686
commit9517bd9234f1a8978490b04719e6b704fb8e3686[log] [download]
authorYann Collet <yann.collet.73@gmail.com>Thu Aug 06 03:49:29 2015 +0100
committerYann Collet <yann.collet.73@gmail.com>Thu Aug 06 03:49:29 2015 +0100
treebece7ef8260820ee6d93069df8d551c57eb1e71e
parenta60d11e468168c53740df6674bf610d05c70a3fb [diff]
minor simplification lz4_readarch()
2 files changed
tree: bece7ef8260820ee6d93069df8d551c57eb1e71e
  1. .gitattributes
  2. .travis.yml
  3. Makefile
  4. NEWS
  5. README.md
  6. cmake_unofficial/
  7. contrib/djgpp/
  8. examples/
  9. lib/
  10. lz4_Block_format.md
  11. lz4_Frame_format.md
  12. programs/
  13. versionsTest/
  14. visual/2012/
README.md

LZ4 - Extremely fast compression

LZ4 is lossless compression algorithm, providing compression speed at 400 MB/s per core, scalable with multi-cores CPU. It also features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.

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.

BranchStatus
masterBuild Status Build status coverity
devBuild Status Build status

Branch Policy:

  • The “master” branch is considered stable, at all times.
  • The “dev” branch is the one where all contributions must be merged before being promoted to master.
    • If you plan to propose a patch, please commit into the “dev” branch, or its own feature branch. Direct commit to “master” are not permitted.

Benchmarks

The benchmark uses the Open-Source Benchmark program by m^2 (v0.14.3) compiled with GCC v4.8.2 on Linux Mint 64-bits v17. The reference system uses a Core i5-4300U @1.9GHz. Benchmark evaluates the compression of reference Silesia Corpus in single-thread mode.

CompressorRatioCompressionDecompression
memcpy1.0004200 MB/s4200 MB/s
LZ4 fast 17 (r129)1.607690 MB/s2220 MB/s
LZ4 default (r129)2.101385 MB/s1850 MB/s
LZO 2.062.108350 MB/s510 MB/s
QuickLZ 1.5.1.b62.238320 MB/s380 MB/s
Snappy 1.1.02.091250 MB/s960 MB/s
LZF v3.62.073175 MB/s500 MB/s
zlib 1.2.8 -12.73059 MB/s250 MB/s
LZ4 HC (r129)2.72022 MB/s1830 MB/s
zlib 1.2.8 -63.09918 MB/s270 MB/s

Documentation

The raw LZ4 block compression format is detailed within lz4_Block_format.

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.

Other source versions

Beyond the C reference source, many contributors have created versions of lz4 in multiple languages (Java, C#, Python, Perl, Ruby, etc.). A list of known source ports is maintained on the LZ4 Homepage.