source: trip-planner-front/node_modules/base64-js/index.js@ 6a3a178

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

initial commit

  • Property mode set to 100644
File size: 3.8 KB
Line 
1'use strict'
2
3exports.byteLength = byteLength
4exports.toByteArray = toByteArray
5exports.fromByteArray = fromByteArray
6
7var lookup = []
8var revLookup = []
9var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array
10
11var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
12for (var i = 0, len = code.length; i < len; ++i) {
13 lookup[i] = code[i]
14 revLookup[code.charCodeAt(i)] = i
15}
16
17// Support decoding URL-safe base64 strings, as Node.js does.
18// See: https://en.wikipedia.org/wiki/Base64#URL_applications
19revLookup['-'.charCodeAt(0)] = 62
20revLookup['_'.charCodeAt(0)] = 63
21
22function getLens (b64) {
23 var len = b64.length
24
25 if (len % 4 > 0) {
26 throw new Error('Invalid string. Length must be a multiple of 4')
27 }
28
29 // Trim off extra bytes after placeholder bytes are found
30 // See: https://github.com/beatgammit/base64-js/issues/42
31 var validLen = b64.indexOf('=')
32 if (validLen === -1) validLen = len
33
34 var placeHoldersLen = validLen === len
35 ? 0
36 : 4 - (validLen % 4)
37
38 return [validLen, placeHoldersLen]
39}
40
41// base64 is 4/3 + up to two characters of the original data
42function byteLength (b64) {
43 var lens = getLens(b64)
44 var validLen = lens[0]
45 var placeHoldersLen = lens[1]
46 return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
47}
48
49function _byteLength (b64, validLen, placeHoldersLen) {
50 return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
51}
52
53function toByteArray (b64) {
54 var tmp
55 var lens = getLens(b64)
56 var validLen = lens[0]
57 var placeHoldersLen = lens[1]
58
59 var arr = new Arr(_byteLength(b64, validLen, placeHoldersLen))
60
61 var curByte = 0
62
63 // if there are placeholders, only get up to the last complete 4 chars
64 var len = placeHoldersLen > 0
65 ? validLen - 4
66 : validLen
67
68 var i
69 for (i = 0; i < len; i += 4) {
70 tmp =
71 (revLookup[b64.charCodeAt(i)] << 18) |
72 (revLookup[b64.charCodeAt(i + 1)] << 12) |
73 (revLookup[b64.charCodeAt(i + 2)] << 6) |
74 revLookup[b64.charCodeAt(i + 3)]
75 arr[curByte++] = (tmp >> 16) & 0xFF
76 arr[curByte++] = (tmp >> 8) & 0xFF
77 arr[curByte++] = tmp & 0xFF
78 }
79
80 if (placeHoldersLen === 2) {
81 tmp =
82 (revLookup[b64.charCodeAt(i)] << 2) |
83 (revLookup[b64.charCodeAt(i + 1)] >> 4)
84 arr[curByte++] = tmp & 0xFF
85 }
86
87 if (placeHoldersLen === 1) {
88 tmp =
89 (revLookup[b64.charCodeAt(i)] << 10) |
90 (revLookup[b64.charCodeAt(i + 1)] << 4) |
91 (revLookup[b64.charCodeAt(i + 2)] >> 2)
92 arr[curByte++] = (tmp >> 8) & 0xFF
93 arr[curByte++] = tmp & 0xFF
94 }
95
96 return arr
97}
98
99function tripletToBase64 (num) {
100 return lookup[num >> 18 & 0x3F] +
101 lookup[num >> 12 & 0x3F] +
102 lookup[num >> 6 & 0x3F] +
103 lookup[num & 0x3F]
104}
105
106function encodeChunk (uint8, start, end) {
107 var tmp
108 var output = []
109 for (var i = start; i < end; i += 3) {
110 tmp =
111 ((uint8[i] << 16) & 0xFF0000) +
112 ((uint8[i + 1] << 8) & 0xFF00) +
113 (uint8[i + 2] & 0xFF)
114 output.push(tripletToBase64(tmp))
115 }
116 return output.join('')
117}
118
119function fromByteArray (uint8) {
120 var tmp
121 var len = uint8.length
122 var extraBytes = len % 3 // if we have 1 byte left, pad 2 bytes
123 var parts = []
124 var maxChunkLength = 16383 // must be multiple of 3
125
126 // go through the array every three bytes, we'll deal with trailing stuff later
127 for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
128 parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength)))
129 }
130
131 // pad the end with zeros, but make sure to not forget the extra bytes
132 if (extraBytes === 1) {
133 tmp = uint8[len - 1]
134 parts.push(
135 lookup[tmp >> 2] +
136 lookup[(tmp << 4) & 0x3F] +
137 '=='
138 )
139 } else if (extraBytes === 2) {
140 tmp = (uint8[len - 2] << 8) + uint8[len - 1]
141 parts.push(
142 lookup[tmp >> 10] +
143 lookup[(tmp >> 4) & 0x3F] +
144 lookup[(tmp << 2) & 0x3F] +
145 '='
146 )
147 }
148
149 return parts.join('')
150}
Note: See TracBrowser for help on using the repository browser.