64 lines
1.1 KiB
JavaScript
64 lines
1.1 KiB
JavaScript
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/*!
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* range-parser
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* Copyright(c) 2012-2014 TJ Holowaychuk
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* MIT Licensed
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*/
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'use strict';
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/**
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* Module exports.
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* @public
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*/
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module.exports = rangeParser;
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/**
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* Parse "Range" header `str` relative to the given file `size`.
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*
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* @param {Number} size
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* @param {String} str
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* @return {Array}
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* @public
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*/
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function rangeParser(size, str) {
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var valid = true;
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var i = str.indexOf('=');
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if (-1 == i) return -2;
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var arr = str.slice(i + 1).split(',').map(function(range){
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var range = range.split('-')
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, start = parseInt(range[0], 10)
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, end = parseInt(range[1], 10);
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// -nnn
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if (isNaN(start)) {
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start = size - end;
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end = size - 1;
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// nnn-
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} else if (isNaN(end)) {
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end = size - 1;
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}
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// limit last-byte-pos to current length
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if (end > size - 1) end = size - 1;
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// invalid
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if (isNaN(start)
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|| isNaN(end)
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|| start > end
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|| start < 0) valid = false;
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return {
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start: start,
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end: end
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};
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});
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arr.type = str.slice(0, i);
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return valid ? arr : -1;
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}
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