1. 压缩与解压缩处理
可以使用zlib模块进行压缩及解压缩处理,压缩文件以后可以减少体积，加快传输速度和节约带宽 代码
2. 压缩对象
压缩和解压缩对象都是一个可读可写流
| 方法 | 说明 |
|---|---|
| zlib.createGzip | 返回Gzip流对象，使用Gzip算法对数据进行压缩处理 |
| zlib.createGunzip | 返回Gzip流对象，使用Gzip算法对压缩的数据进行解压缩处理 |
| zlib.createDeflate | 返回Deflate流对象，使用Deflate算法对数据进行压缩处理 |
| zlib.createInflate | 返回Deflate流对象，使用Deflate算法对数据进行解压缩处理 |
3. 压缩和解压缩
var zlib = require('zlib');
var fs = require('fs');function zip(src) {var gzip = zlib.createGzip();//创建压缩流var inputStream = fs.createReadStream(src);var outputStream = fs.createWriteStream(src+'.gz');inputStream.pipe(gzip).pipe(outputStream);
}
zip('source.txt');function unzip(src){var gunzip = zlib.createGunzip();var inputStream = fs.createReadStream(src);var outputStream = fs.createWriteStream(src.slice(0,-3));inputStream.pipe(gunzip).pipe(outputStream);
}unzip('source.txt.gz');复制代码4. 在http中的应用
var zlib = require('zlib');
var fs = require('fs');
var http = require('http');
http.createServer(function (request, response) {var raw = fs.createReadStream('.' + request.url);var acceptEncoding = request.headers['accept-encoding'];if (!acceptEncoding) {acceptEncoding = '';}if (acceptEncoding.match(/\bdeflate\b/)) {response.setHeader('Content-Encoding','deflate');raw.pipe(zlib.createDeflate()).pipe(response);} else if (acceptEncoding.match(/\bgzip\b/)) {response.setHeader('Content-Encoding','gzip');raw.pipe(zlib.createGzip()).pipe(response);} else {raw.pipe(response);}
}).listen(9090)
复制代码var zlib = require('zlib');
var fs = require('fs');
var http = require('http');var request = http.get({host: 'localhost',path: '/index.html',port: 9090,headers: {'accept-encoding': 'gzip,deflate'}
})request.on('response', function (response) {var output = fs.createWriteStream('test.txt');switch (response.headers['content-encoding']) {case 'gzip':response.pipe(zlib.createGunzip()).pipe(output);break;case 'deflate':response.pipe(zlib.createInflate()).pipe(output);break;default:response.pipe(output);break;}
});
request.end();
复制代码5. 方法调用
var zlib = require('zlib');
var fs = require('fs');var out = fs.createWriteStream('input.log');
var input = 'input';
zlib.gzip(input, function (err, buffer) {if (!err) {zlib.unzip(buffer, function (err, buffer) {if (!err) {console.log(buffer.toString());out.end(buffer);}})}
})复制代码
