+++ /dev/null
-module.exports = preferredCharsets;
-preferredCharsets.preferredCharsets = preferredCharsets;
-
-function parseAcceptCharset(accept) {
- var accepts = accept.split(',');
-
- for (var i = 0, j = 0; i < accepts.length; i++) {
- var charset = parseCharset(accepts[i].trim(), i);
-
- if (charset) {
- accepts[j++] = charset;
- }
- }
-
- // trim accepts
- accepts.length = j;
-
- return accepts;
-}
-
-function parseCharset(s, i) {
- var match = s.match(/^\s*(\S+?)\s*(?:;(.*))?$/);
- if (!match) return null;
-
- var charset = 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 {
- charset: charset,
- q: q,
- i: i
- };
-}
-
-function getCharsetPriority(charset, accepted, index) {
- var priority = {o: -1, q: 0, s: 0};
-
- for (var i = 0; i < accepted.length; i++) {
- var spec = specify(charset, accepted[i], index);
-
- if (spec && (priority.s - spec.s || priority.q - spec.q || priority.o - spec.o) < 0) {
- priority = spec;
- }
- }
-
- return priority;
-}
-
-function specify(charset, spec, index) {
- var s = 0;
- if(spec.charset.toLowerCase() === charset.toLowerCase()){
- s |= 1;
- } else if (spec.charset !== '*' ) {
- return null
- }
-
- return {
- i: index,
- o: spec.i,
- q: spec.q,
- s: s
- }
-}
-
-function preferredCharsets(accept, provided) {
- // RFC 2616 sec 14.2: no header = *
- var accepts = parseAcceptCharset(accept === undefined ? '*' : accept || '');
-
- if (!provided) {
- // sorted list of all charsets
- return accepts.filter(isQuality).sort(compareSpecs).map(function getCharset(spec) {
- return spec.charset;
- });
- }
-
- var priorities = provided.map(function getPriority(type, index) {
- return getCharsetPriority(type, accepts, index);
- });
-
- // sorted list of accepted charsets
- return priorities.filter(isQuality).sort(compareSpecs).map(function getCharset(priority) {
- return provided[priorities.indexOf(priority)];
- });
-}
-
-function compareSpecs(a, b) {
- return (b.q - a.q) || (b.s - a.s) || (a.o - b.o) || (a.i - b.i) || 0;
-}
-
-function isQuality(spec) {
- return spec.q > 0;
-}