From 67fdec20726e48ba3a934cb25bb30d47ec4a4f29 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Yaroslav=20De=20La=20Pe=C3=B1a=20Smirnov?= Date: Wed, 29 Nov 2017 11:44:34 +0300 Subject: Initial commit, version 0.5.3 --- node_modules/negotiator/lib/encoding.js | 184 ++++++++++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 node_modules/negotiator/lib/encoding.js (limited to 'node_modules/negotiator/lib/encoding.js') diff --git a/node_modules/negotiator/lib/encoding.js b/node_modules/negotiator/lib/encoding.js new file mode 100644 index 0000000..70ac3de --- /dev/null +++ b/node_modules/negotiator/lib/encoding.js @@ -0,0 +1,184 @@ +/** + * negotiator + * Copyright(c) 2012 Isaac Z. Schlueter + * Copyright(c) 2014 Federico Romero + * Copyright(c) 2014-2015 Douglas Christopher Wilson + * MIT Licensed + */ + +'use strict'; + +/** + * Module exports. + * @public + */ + +module.exports = preferredEncodings; +module.exports.preferredEncodings = preferredEncodings; + +/** + * Module variables. + * @private + */ + +var simpleEncodingRegExp = /^\s*([^\s;]+)\s*(?:;(.*))?$/; + +/** + * Parse the Accept-Encoding header. + * @private + */ + +function parseAcceptEncoding(accept) { + var accepts = accept.split(','); + var hasIdentity = false; + var minQuality = 1; + + for (var i = 0, j = 0; i < accepts.length; i++) { + var encoding = parseEncoding(accepts[i].trim(), i); + + if (encoding) { + accepts[j++] = encoding; + hasIdentity = hasIdentity || specify('identity', encoding); + minQuality = Math.min(minQuality, encoding.q || 1); + } + } + + if (!hasIdentity) { + /* + * If identity doesn't explicitly appear in the accept-encoding header, + * it's added to the list of acceptable encoding with the lowest q + */ + accepts[j++] = { + encoding: 'identity', + q: minQuality, + i: i + }; + } + + // trim accepts + accepts.length = j; + + return accepts; +} + +/** + * Parse an encoding from the Accept-Encoding header. + * @private + */ + +function parseEncoding(str, i) { + var match = simpleEncodingRegExp.exec(str); + if (!match) return null; + + var encoding = match[1]; + var q = 1; + if (match[2]) { + var params = match[2].split(';'); + for (var i = 0; i < params.length; i ++) { + var p = params[i].trim().split('='); + if (p[0] === 'q') { + q = parseFloat(p[1]); + break; + } + } + } + + return { + encoding: encoding, + q: q, + i: i + }; +} + +/** + * Get the priority of an encoding. + * @private + */ + +function getEncodingPriority(encoding, accepted, index) { + var priority = {o: -1, q: 0, s: 0}; + + for (var i = 0; i < accepted.length; i++) { + var spec = specify(encoding, accepted[i], index); + + if (spec && (priority.s - spec.s || priority.q - spec.q || priority.o - spec.o) < 0) { + priority = spec; + } + } + + return priority; +} + +/** + * Get the specificity of the encoding. + * @private + */ + +function specify(encoding, spec, index) { + var s = 0; + if(spec.encoding.toLowerCase() === encoding.toLowerCase()){ + s |= 1; + } else if (spec.encoding !== '*' ) { + return null + } + + return { + i: index, + o: spec.i, + q: spec.q, + s: s + } +}; + +/** + * Get the preferred encodings from an Accept-Encoding header. + * @public + */ + +function preferredEncodings(accept, provided) { + var accepts = parseAcceptEncoding(accept || ''); + + if (!provided) { + // sorted list of all encodings + return accepts + .filter(isQuality) + .sort(compareSpecs) + .map(getFullEncoding); + } + + var priorities = provided.map(function getPriority(type, index) { + return getEncodingPriority(type, accepts, index); + }); + + // sorted list of accepted encodings + return priorities.filter(isQuality).sort(compareSpecs).map(function getEncoding(priority) { + return provided[priorities.indexOf(priority)]; + }); +} + +/** + * Compare two specs. + * @private + */ + +function compareSpecs(a, b) { + return (b.q - a.q) || (b.s - a.s) || (a.o - b.o) || (a.i - b.i) || 0; +} + +/** + * Get full encoding string. + * @private + */ + +function getFullEncoding(spec) { + return spec.encoding; +} + +/** + * Check if a spec has any quality. + * @private + */ + +function isQuality(spec) { + return spec.q > 0; +} -- cgit v1.2.3