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Diffstat (limited to 'node_modules/express/node_modules/connect/lib/middleware/compress.js')
| -rw-r--r-- | node_modules/express/node_modules/connect/lib/middleware/compress.js | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/node_modules/express/node_modules/connect/lib/middleware/compress.js b/node_modules/express/node_modules/connect/lib/middleware/compress.js new file mode 100644 index 0000000..e71ea8c --- /dev/null +++ b/node_modules/express/node_modules/connect/lib/middleware/compress.js @@ -0,0 +1,152 @@ +/*! + * Connect - compress + * Copyright(c) 2010 Sencha Inc. + * Copyright(c) 2011 TJ Holowaychuk + * MIT Licensed + */ + +/** + * Module dependencies. + */ + +var zlib = require('zlib'); + +/** + * Supported content-encoding methods. + */ + +exports.methods = { + gzip: zlib.createGzip + , deflate: zlib.createDeflate +}; + +/** + * Default filter function. + */ + +exports.filter = function(req, res){ + return /json|text|javascript/.test(res.getHeader('Content-Type')); +}; + +/** + * Compress: + * + * Compress response data with gzip/deflate. + * + * Filter: + * + * A `filter` callback function may be passed to + * replace the default logic of: + * + * exports.filter = function(req, res){ + * return /json|text|javascript/.test(res.getHeader('Content-Type')); + * }; + * + * Options: + * + * All remaining options are passed to the gzip/deflate + * creation functions. Consult node's docs for additional details. + * + * - `chunkSize` (default: 16*1024) + * - `windowBits` + * - `level`: 0-9 where 0 is no compression, and 9 is slow but best compression + * - `memLevel`: 1-9 low is slower but uses less memory, high is fast but uses more + * - `strategy`: compression strategy + * + * @param {Object} options + * @return {Function} + * @api public + */ + +module.exports = function compress(options) { + options = options || {}; + var names = Object.keys(exports.methods) + , filter = options.filter || exports.filter; + + return function compress(req, res, next){ + var accept = req.headers['accept-encoding'] + , vary = res.getHeader('Vary') + , write = res.write + , end = res.end + , stream + , method; + + // vary + if (!vary) { + res.setHeader('Vary', 'Accept-Encoding'); + } else if (!~vary.indexOf('Accept-Encoding')) { + res.setHeader('Vary', vary + ', Accept-Encoding'); + } + + // proxy + + res.write = function(chunk, encoding){ + if (!this.headerSent) this._implicitHeader(); + return stream + ? stream.write(new Buffer(chunk, encoding)) + : write.call(res, chunk, encoding); + }; + + res.end = function(chunk, encoding){ + if (chunk) this.write(chunk, encoding); + return stream + ? stream.end() + : end.call(res); + }; + + res.on('header', function(){ + var encoding = res.getHeader('Content-Encoding') || 'identity'; + + // already encoded + if ('identity' != encoding) return; + + // default request filter + if (!filter(req, res)) return; + + // SHOULD use identity + if (!accept) return; + + // head + if ('HEAD' == req.method) return; + + // default to gzip + if ('*' == accept.trim()) method = 'gzip'; + + // compression method + if (!method) { + for (var i = 0, len = names.length; i < len; ++i) { + if (~accept.indexOf(names[i])) { + method = names[i]; + break; + } + } + } + + // compression method + if (!method) return; + + // compression stream + stream = exports.methods[method](options); + + // header fields + res.setHeader('Content-Encoding', method); + res.removeHeader('Content-Length'); + + // compression + + stream.on('data', function(chunk){ + write.call(res, chunk); + }); + + stream.on('end', function(){ + end.call(res); + }); + + stream.on('drain', function() { + res.emit('drain'); + }); + }); + + next(); + }; +}; |
