source: trip-planner-front/node_modules/range-parser/index.js@ eed0bf8

Last change on this file since eed0bf8 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

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1/*!
2 * range-parser
3 * Copyright(c) 2012-2014 TJ Holowaychuk
4 * Copyright(c) 2015-2016 Douglas Christopher Wilson
5 * MIT Licensed
6 */
7
8'use strict'
9
10/**
11 * Module exports.
12 * @public
13 */
14
15module.exports = rangeParser
16
17/**
18 * Parse "Range" header `str` relative to the given file `size`.
19 *
20 * @param {Number} size
21 * @param {String} str
22 * @param {Object} [options]
23 * @return {Array}
24 * @public
25 */
26
27function rangeParser (size, str, options) {
28 if (typeof str !== 'string') {
29 throw new TypeError('argument str must be a string')
30 }
31
32 var index = str.indexOf('=')
33
34 if (index === -1) {
35 return -2
36 }
37
38 // split the range string
39 var arr = str.slice(index + 1).split(',')
40 var ranges = []
41
42 // add ranges type
43 ranges.type = str.slice(0, index)
44
45 // parse all ranges
46 for (var i = 0; i < arr.length; i++) {
47 var range = arr[i].split('-')
48 var start = parseInt(range[0], 10)
49 var end = parseInt(range[1], 10)
50
51 // -nnn
52 if (isNaN(start)) {
53 start = size - end
54 end = size - 1
55 // nnn-
56 } else if (isNaN(end)) {
57 end = size - 1
58 }
59
60 // limit last-byte-pos to current length
61 if (end > size - 1) {
62 end = size - 1
63 }
64
65 // invalid or unsatisifiable
66 if (isNaN(start) || isNaN(end) || start > end || start < 0) {
67 continue
68 }
69
70 // add range
71 ranges.push({
72 start: start,
73 end: end
74 })
75 }
76
77 if (ranges.length < 1) {
78 // unsatisifiable
79 return -1
80 }
81
82 return options && options.combine
83 ? combineRanges(ranges)
84 : ranges
85}
86
87/**
88 * Combine overlapping & adjacent ranges.
89 * @private
90 */
91
92function combineRanges (ranges) {
93 var ordered = ranges.map(mapWithIndex).sort(sortByRangeStart)
94
95 for (var j = 0, i = 1; i < ordered.length; i++) {
96 var range = ordered[i]
97 var current = ordered[j]
98
99 if (range.start > current.end + 1) {
100 // next range
101 ordered[++j] = range
102 } else if (range.end > current.end) {
103 // extend range
104 current.end = range.end
105 current.index = Math.min(current.index, range.index)
106 }
107 }
108
109 // trim ordered array
110 ordered.length = j + 1
111
112 // generate combined range
113 var combined = ordered.sort(sortByRangeIndex).map(mapWithoutIndex)
114
115 // copy ranges type
116 combined.type = ranges.type
117
118 return combined
119}
120
121/**
122 * Map function to add index value to ranges.
123 * @private
124 */
125
126function mapWithIndex (range, index) {
127 return {
128 start: range.start,
129 end: range.end,
130 index: index
131 }
132}
133
134/**
135 * Map function to remove index value from ranges.
136 * @private
137 */
138
139function mapWithoutIndex (range) {
140 return {
141 start: range.start,
142 end: range.end
143 }
144}
145
146/**
147 * Sort function to sort ranges by index.
148 * @private
149 */
150
151function sortByRangeIndex (a, b) {
152 return a.index - b.index
153}
154
155/**
156 * Sort function to sort ranges by start position.
157 * @private
158 */
159
160function sortByRangeStart (a, b) {
161 return a.start - b.start
162}
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