README.md - lz4 - Rivoreo Source Code Repositories

 LZ4 - Extremely fast compression
 ================================

 LZ4 is lossless compression algorithm,
 providing compression speed at 400 MB/s per core,
 scalable with multi-cores CPU.
 It 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 decompression speed.

 LZ4 library is provided as open-source software using BSD 2-Clause license.


 |Branch      |Status   |
 |------------|---------|
 |master      | [![Build Status][travisMasterBadge]][travisLink] [![Build status][AppveyorMasterBadge]][AppveyorLink] [![coverity][coverBadge]][coverlink] |
 |dev         | [![Build Status][travisDevBadge]][travisLink]    [![Build status][AppveyorDevBadge]][AppveyorLink]                                         |

 [travisMasterBadge]: https://travis-ci.org/lz4/lz4.svg?branch=master "Continuous Integration test suite"
 [travisDevBadge]: https://travis-ci.org/lz4/lz4.svg?branch=dev "Continuous Integration test suite"
 [travisLink]: https://travis-ci.org/lz4/lz4
 [AppveyorMasterBadge]: https://ci.appveyor.com/api/projects/status/github/lz4/lz4?branch=master&svg=true "Windows test suite"
 [AppveyorDevBadge]: https://ci.appveyor.com/api/projects/status/github/lz4/lz4?branch=dev&svg=true "Windows test suite"
 [AppveyorLink]: https://ci.appveyor.com/project/YannCollet/lz4-1lndh
 [coverBadge]: https://scan.coverity.com/projects/4735/badge.svg "Static code analysis of Master branch"
 [coverlink]: https://scan.coverity.com/projects/4735

 > **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 [lzbench], from @inikep
 compiled with GCC v6.2.0 on Linux 64-bits.
 The reference system uses a Core i7-3930K CPU @ 4.5GHz.
 Benchmark evaluates the compression of reference [Silesia Corpus]
 in single-thread mode.

 [lzbench]: https://github.com/inikep/lzbench
 [Silesia Corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia

 |  Compressor            | Ratio   | Compression | Decompression |
 |  ----------            | -----   | ----------- | ------------- |
 |  memcpy                |  1.000  | 7300 MB/s   |   7300 MB/s   |
 |**LZ4 fast 8  (v1.7.3)**|  1.799  |**911 MB/s** | **3360 MB/s** |
 |**LZ4 default (v1.7.3)**|**2.101**|**625 MB/s** | **3220 MB/s** |
 |  LZO 2.09              |  2.108  |  620 MB/s   |    845 MB/s   |
 |  QuickLZ 1.5.0         |  2.238  |  510 MB/s   |    600 MB/s   |
 |  Snappy 1.1.3          |  2.091  |  450 MB/s   |   1550 MB/s   |
 |  LZF v3.6              |  2.073  |  365 MB/s   |    820 MB/s   |
 |  [Zstandard] 1.1.1 -1  |  2.876  |  330 MB/s   |    930 MB/s   |
 |  [Zstandard] 1.1.1 -3  |  3.164  |  200 MB/s   |    810 MB/s   |
 | [zlib] deflate 1.2.8 -1|  2.730  |  100 MB/s   |    370 MB/s   |
 |**LZ4 HC -9 (v1.7.3)**  |**2.720**|   34 MB/s   | **3240 MB/s** |
 | [zlib] deflate 1.2.8 -6|  3.099  |   33 MB/s   |    390 MB/s   |

 [zlib]: http://www.zlib.net/
 [Zstandard]: http://www.zstd.net/

 LZ4 is also compatible and well optimized for x32 mode, for which it provides an additional +10% speed performance.


 Installation
 -------------------------

 ```
 make
 make install     # this command may require root access
 ```

 LZ4's `Makefile` supports standard [Makefile conventions],
 including [staged installs], [redirection], or [command redefinition].
 It is compatible with parallel builds (`'-j#'`).

 [Makefile conventions]: https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html
 [staged installs]: https://www.gnu.org/prep/standards/html_node/DESTDIR.html
 [redirection]: https://www.gnu.org/prep/standards/html_node/Directory-Variables.html
 [command redefinition]: https://www.gnu.org/prep/standards/html_node/Utilities-in-Makefiles.html


 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.

 [lz4_Block_format]: doc/lz4_Block_format.md
 [lz4_Frame_format]: doc/lz4_Frame_format.md


 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].

 [LZ4 Homepage]: http://www.lz4.org
	LZ4 - Extremely fast compression
	================================

	LZ4 is lossless compression algorithm,
	providing compression speed at 400 MB/s per core,
	scalable with multi-cores CPU.
	It 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 decompression speed.

	LZ4 library is provided as open-source software using BSD 2-Clause license.


	\|Branch \|Status \|
	\|------------\|---------\|
	\|master \| [![Build Status][travisMasterBadge]][travisLink] [![Build status][AppveyorMasterBadge]][AppveyorLink] [![coverity][coverBadge]][coverlink] \|
	\|dev \| [![Build Status][travisDevBadge]][travisLink] [![Build status][AppveyorDevBadge]][AppveyorLink] \|

	[travisMasterBadge]: https://travis-ci.org/lz4/lz4.svg?branch=master "Continuous Integration test suite"
	[travisDevBadge]: https://travis-ci.org/lz4/lz4.svg?branch=dev "Continuous Integration test suite"
	[travisLink]: https://travis-ci.org/lz4/lz4
	[AppveyorMasterBadge]: https://ci.appveyor.com/api/projects/status/github/lz4/lz4?branch=master&svg=true "Windows test suite"
	[AppveyorDevBadge]: https://ci.appveyor.com/api/projects/status/github/lz4/lz4?branch=dev&svg=true "Windows test suite"
	[AppveyorLink]: https://ci.appveyor.com/project/YannCollet/lz4-1lndh
	[coverBadge]: https://scan.coverity.com/projects/4735/badge.svg "Static code analysis of Master branch"
	[coverlink]: https://scan.coverity.com/projects/4735

	> 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 [lzbench], from @inikep
	compiled with GCC v6.2.0 on Linux 64-bits.
	The reference system uses a Core i7-3930K CPU @ 4.5GHz.
	Benchmark evaluates the compression of reference [Silesia Corpus]
	in single-thread mode.

	[lzbench]: https://github.com/inikep/lzbench
	[Silesia Corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia

	\| Compressor \| Ratio \| Compression \| Decompression \|
	\| ---------- \| ----- \| ----------- \| ------------- \|
	\| memcpy \| 1.000 \| 7300 MB/s \| 7300 MB/s \|
	\|LZ4 fast 8 (v1.7.3)\| 1.799 \|911 MB/s \| 3360 MB/s \|
	\|LZ4 default (v1.7.3)\|2.101\|625 MB/s \| 3220 MB/s \|
	\| LZO 2.09 \| 2.108 \| 620 MB/s \| 845 MB/s \|
	\| QuickLZ 1.5.0 \| 2.238 \| 510 MB/s \| 600 MB/s \|
	\| Snappy 1.1.3 \| 2.091 \| 450 MB/s \| 1550 MB/s \|
	\| LZF v3.6 \| 2.073 \| 365 MB/s \| 820 MB/s \|
	\| [Zstandard] 1.1.1 -1 \| 2.876 \| 330 MB/s \| 930 MB/s \|
	\| [Zstandard] 1.1.1 -3 \| 3.164 \| 200 MB/s \| 810 MB/s \|
	\| [zlib] deflate 1.2.8 -1\| 2.730 \| 100 MB/s \| 370 MB/s \|
	\|LZ4 HC -9 (v1.7.3) \|2.720\| 34 MB/s \| 3240 MB/s \|
	\| [zlib] deflate 1.2.8 -6\| 3.099 \| 33 MB/s \| 390 MB/s \|

	[zlib]: http://www.zlib.net/
	[Zstandard]: http://www.zstd.net/

	LZ4 is also compatible and well optimized for x32 mode, for which it provides an additional +10% speed performance.


	Installation
	-------------------------

	```
	make
	make install # this command may require root access
	```

	LZ4's `Makefile` supports standard [Makefile conventions],
	including [staged installs], [redirection], or [command redefinition].
	It is compatible with parallel builds (`'-j#'`).

	[Makefile conventions]: https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html
	[staged installs]: https://www.gnu.org/prep/standards/html_node/DESTDIR.html
	[redirection]: https://www.gnu.org/prep/standards/html_node/Directory-Variables.html
	[command redefinition]: https://www.gnu.org/prep/standards/html_node/Utilities-in-Makefiles.html


	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.

	[lz4_Block_format]: doc/lz4_Block_format.md
	[lz4_Frame_format]: doc/lz4_Frame_format.md


	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].

	[LZ4 Homepage]: http://www.lz4.org