minor readme formatting update

This commit is contained in:
Yann Collet 2017-12-15 13:26:39 -08:00
parent f0b0789215
commit 78de28239f
2 changed files with 24 additions and 23 deletions

View File

@ -1,14 +1,15 @@
__Zstandard__, or `zstd` as short version, is a fast lossless compression algorithm, <p align="center"><img src="https://raw.githubusercontent.com/facebook/zstd/readme/doc/images/zstd_logo86.png" alt="Zstandard"></p>
targeting real-time compression scenarios at zlib-level and better compression ratios.
It is provided as an open-source BSD-licensed **C** library, __Zstandard__, or `zstd` as short version, is a fast lossless compression algorithm,
and a command line utility producing and decoding `.zst` and `.gz` files. targeting real-time compression scenarios at zlib-level and better compression ratios.
For other programming languages, It's backed by a very fast entropy stage, provided by [Huff0 and FSE library](https://github.com/Cyan4973/FiniteStateEntropy).
you can consult a list of known ports on [Zstandard homepage](http://www.zstd.net/#other-languages).
| dev branch status | The project is provided as an open-source BSD-licensed **C** library,
|-------------------| and a command line utility producing and decoding `.zst`, `.gz`, `.xz` and `.lz4` files.
| [![Build Status][travisDevBadge]][travisLink] [![Build status][AppveyorDevBadge]][AppveyorLink] [![Build status][CircleDevBadge]][CircleLink] Should your project require another programming language,
a list of known ports and bindings is provided on [Zstandard homepage](http://www.zstd.net/#other-languages).
Development branch status : [![Build Status][travisDevBadge]][travisLink] [![Build status][AppveyorDevBadge]][AppveyorLink] [![Build status][CircleDevBadge]][CircleLink]
[travisDevBadge]: https://travis-ci.org/facebook/zstd.svg?branch=dev "Continuous Integration test suite" [travisDevBadge]: https://travis-ci.org/facebook/zstd.svg?branch=dev "Continuous Integration test suite"
[travisLink]: https://travis-ci.org/facebook/zstd [travisLink]: https://travis-ci.org/facebook/zstd
@ -17,8 +18,9 @@ you can consult a list of known ports on [Zstandard homepage](http://www.zstd.ne
[CircleDevBadge]: https://circleci.com/gh/facebook/zstd/tree/dev.svg?style=shield "Short test suite" [CircleDevBadge]: https://circleci.com/gh/facebook/zstd/tree/dev.svg?style=shield "Short test suite"
[CircleLink]: https://circleci.com/gh/facebook/zstd [CircleLink]: https://circleci.com/gh/facebook/zstd
### Benchmarks
As a reference, several fast compression algorithms were tested and compared For reference, several fast compression algorithms were tested and compared
on a server running Linux Debian (`Linux version 4.8.0-1-amd64`), on a server running Linux Debian (`Linux version 4.8.0-1-amd64`),
with a Core i7-6700K CPU @ 4.0GHz, with a Core i7-6700K CPU @ 4.0GHz,
using [lzbench], an open-source in-memory benchmark by @inikep using [lzbench], an open-source in-memory benchmark by @inikep
@ -43,7 +45,9 @@ on the [Silesia compression corpus].
[LZ4]: http://www.lz4.org/ [LZ4]: http://www.lz4.org/
Zstd can also offer stronger compression ratios at the cost of compression speed. Zstd can also offer stronger compression ratios at the cost of compression speed.
Speed vs Compression trade-off is configurable by small increments. Decompression speed is preserved and remains roughly the same at all settings, a property shared by most LZ compression algorithms, such as [zlib] or lzma. Speed vs Compression trade-off is configurable by small increments.
Decompression speed is preserved and remains roughly the same at all settings,
a property shared by most LZ compression algorithms, such as [zlib] or lzma.
The following tests were run The following tests were run
on a server running Linux Debian (`Linux version 4.8.0-1-amd64`) on a server running Linux Debian (`Linux version 4.8.0-1-amd64`)
@ -56,8 +60,8 @@ Compression Speed vs Ratio | Decompression Speed
---------------------------|-------------------- ---------------------------|--------------------
![Compression Speed vs Ratio](doc/images/Cspeed4.png "Compression Speed vs Ratio") | ![Decompression Speed](doc/images/Dspeed4.png "Decompression Speed") ![Compression Speed vs Ratio](doc/images/Cspeed4.png "Compression Speed vs Ratio") | ![Decompression Speed](doc/images/Dspeed4.png "Decompression Speed")
Several algorithms can produce higher compression ratios, but at slower speeds, falling outside of the graph. A few other algorithms can produce higher compression ratios at slower speeds, falling outside of the graph.
For a larger picture including very slow modes, [click on this link](doc/images/DCspeed5.png). For a larger picture including slow modes, [click on this link](doc/images/DCspeed5.png).
### The case for Small Data compression ### The case for Small Data compression
@ -99,19 +103,16 @@ Dictionary gains are mostly effective in the first few KB. Then, the compression
`zstd -D dictionaryName --decompress FILE.zst` `zstd -D dictionaryName --decompress FILE.zst`
### Build ### Build instructions
Once you have the repository cloned, there are multiple ways provided to build Zstandard.
#### Makefile #### Makefile
If your system is compatible with a standard `make` (or `gmake`) binary generator, If your system is compatible with standard `make` (or `gmake`),
you can simply run it at the root directory. invoking `make` in root directory will generate `zstd` cli in root directory.
It will generate `zstd` within root directory.
Other available options include: Other available options include:
- `make install` : create and install zstd binary, library and man page - `make install` : create and install zstd cli, library and man pages
- `make test` : create and run `zstd` and test tools on local platform - `make check` : create and run `zstd`, tests its behavior on local platform
#### cmake #### cmake
@ -143,8 +144,8 @@ Zstandard is dual-licensed under [BSD](LICENSE) and [GPLv2](COPYING).
### Contributing ### Contributing
The "dev" branch is the one where all contributions will be merged before reaching "master". The "dev" branch is the one where all contributions are merged before reaching "master".
If you plan to propose a patch, please commit into the "dev" branch or its own feature branch. 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. Direct commit to "master" are not permitted.
For more information, please read [CONTRIBUTING](CONTRIBUTING.md). For more information, please read [CONTRIBUTING](CONTRIBUTING.md).

BIN
doc/images/zstd_logo86.png Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 5.8 KiB