159 lines
4.6 KiB
Markdown
159 lines
4.6 KiB
Markdown
# node-zopfli
|
|
|
|
[![NPM version][npm-image]][npm-url]
|
|
[![Linux Build Status][travis-image]][travis-url]
|
|
[![Windows Build Status][appveyor-image]][appveyor-url]
|
|
[![Coverage Status][coveralls-image]][coveralls-url]
|
|
[![Dependency Status][dep-image]][dep-url]
|
|
[![devDependency Status][devDep-image]][devDep-url]
|
|
[![Stories in Ready][waffle-image]][waffle-url]
|
|
|
|
Node.js bindings for [Zopfli](https://en.wikipedia.org/wiki/Zopfli) compressing library.
|
|
Compress gzip files 5% better compared to gzip.
|
|
|
|
It is considerably slower than gzip (~100x) so you may want to use it only for static content and cached resources.
|
|
|
|
|
|
## Prerequisites for building
|
|
|
|
* Python 2.7
|
|
* GCC (Unix) or Visual Studio Express (Windows), see [Node Building tools](https://github.com/TooTallNate/node-gyp#installation)
|
|
|
|
## Usage
|
|
|
|
### Install
|
|
|
|
```shell
|
|
npm install node-zopfli
|
|
```
|
|
|
|
or if you want zopfli binary globally
|
|
|
|
```shell
|
|
npm install -g node-zopfli
|
|
```
|
|
|
|
### Binary (from command line)
|
|
To gzip a file
|
|
|
|
```shell
|
|
zopfli file.txt
|
|
```
|
|
|
|
To compress a png file
|
|
|
|
```shell
|
|
zopflipng file.png out.png
|
|
```
|
|
|
|
### Usage examples
|
|
#### Stream (async):
|
|
|
|
```js
|
|
var zopfli = require('node-zopfli');
|
|
fs.createReadStream('file.js')
|
|
.pipe(zopfli.createGzip(options))
|
|
.pipe(fs.createWriteStream('file.js.gz'));
|
|
```
|
|
|
|
Instead of `zopfli.createGzip`, you can also use
|
|
|
|
```js
|
|
new Zopfli('gzip', options);
|
|
```
|
|
|
|
#### Buffer (async):
|
|
|
|
```js
|
|
var zopfli = require('node-zopfli');
|
|
var input = new Buffer('I want to be compressed');
|
|
zopfli.deflate(input, options, function(err, deflated) {});
|
|
zopfli.zlib(input, options, function(err, zlibed) {});
|
|
zopfli.gzip(input, options, function(err, gziped) {});
|
|
```
|
|
|
|
#### Buffer (sync):
|
|
|
|
```js
|
|
var zopfli = require('node-zopfli');
|
|
var input = new Buffer('I want to be compressed');
|
|
var deflated = zopfli.deflateSync(input, options);
|
|
var zlibed = zopfli.zlibSync(input, options);
|
|
var gziped = zopfli.gzipSync(input, options);
|
|
```
|
|
|
|
### API
|
|
|
|
#### compress(input, format, [options, callback])
|
|
|
|
`input` is the input buffer
|
|
|
|
`format` can be one of `deflate`, `zlib` and `gzip`
|
|
|
|
`callback`, if present, gets two arguments `(err, buffer)` where `err` is an error object, if any, and `buffer` is the resultant compressed data.
|
|
|
|
If no callback is provided, it returns an A+ Promise.
|
|
|
|
##### aliases
|
|
|
|
`deflate`, `zlib` and `gzip` methods are aliases on `compress` without `format` argument.
|
|
|
|
#### Options
|
|
|
|
Here are the options with defaults values you can pass to zopfli:
|
|
|
|
```js
|
|
{
|
|
verbose: false,
|
|
verbose_more: false,
|
|
numiterations: 15,
|
|
blocksplitting: true,
|
|
blocksplittinglast: false,
|
|
blocksplittingmax: 15
|
|
}
|
|
```
|
|
|
|
##### numiterations
|
|
Maximum amount of times to rerun forward and backward pass to optimize LZ77 compression cost. Good values: 10, 15 for small files, 5 for files over several MB in size or it will be too slow.
|
|
|
|
##### blocksplitting
|
|
If true, splits the data in multiple deflate blocks with optimal choice for the block boundaries. Block splitting gives better compression.
|
|
|
|
##### blocksplittinglast
|
|
If true, chooses the optimal block split points only after doing the iterative LZ77 compression. If false, chooses the block split points first, then does iterative LZ77 on each individual block. Depending on the file, either first or last gives the best compression.
|
|
|
|
##### blocksplittingmax
|
|
Maximum amount of blocks to split into (0 for unlimited, but this can give extreme results that hurt compression on some files).
|
|
|
|
|
|
## Build from sources
|
|
|
|
```shell
|
|
git clone https://github.com/pierreinglebert/node-zopfli --recursive
|
|
cd node-zopfli
|
|
npm install
|
|
```
|
|
|
|
## Tests
|
|
mocha is used for tests, you can run them with:
|
|
|
|
```shell
|
|
npm test
|
|
```
|
|
|
|
|
|
[npm-image]: https://img.shields.io/npm/v/node-zopfli.svg
|
|
[npm-url]: https://www.npmjs.com/package/node-zopfli
|
|
[waffle-image]: https://badge.waffle.io/pierreinglebert/node-zopfli.svg
|
|
[waffle-url]: https://waffle.io/pierreinglebert/node-zopfli
|
|
[travis-image]: https://img.shields.io/travis/pierreinglebert/node-zopfli/master.svg?label=Linux%20build
|
|
[travis-url]: https://travis-ci.org/pierreinglebert/node-zopfli
|
|
[appveyor-image]: https://img.shields.io/appveyor/ci/pierreinglebert/node-zopfli/master.svg?label=Windows%20build
|
|
[appveyor-url]: https://ci.appveyor.com/project/pierreinglebert/node-zopfli/branch/master
|
|
[coveralls-image]: https://img.shields.io/coveralls/pierreinglebert/node-zopfli.svg
|
|
[coveralls-url]: https://coveralls.io/r/pierreinglebert/node-zopfli?branch=master
|
|
[dep-image]: https://img.shields.io/david/pierreinglebert/node-zopfli.svg
|
|
[dep-url]: https://david-dm.org/pierreinglebert/node-zopfli
|
|
[devDep-image]: https://img.shields.io/david/dev/pierreinglebert/node-zopfli.svg
|
|
[devDep-url]: https://david-dm.org/pierreinglebert/node-zopfli#info=devDependencies
|