Sha256: cce8f1829a498ea272fc9662496e950e9391d5909be6e7bae9f568b8b6c301a3
Contents?: true
Size: 1.7 KB
Versions: 5
Compression:
Stored size: 1.7 KB
Contents
'use strict';
/**
* btoa() as defined by the HTML5 spec, which mostly just references RFC4648.
*/
function btoa(s) {
var i;
// String conversion as required by WebIDL.
s = String(s);
// "The btoa() method must throw an INVALID_CHARACTER_ERR exception if the
// method's first argument contains any character whose code point is
// greater than U+00FF."
for (i = 0; i < s.length; i++) {
if (s.charCodeAt(i) > 255) {
return null;
}
}
var out = '';
for (i = 0; i < s.length; i += 3) {
var groupsOfSix = [undefined, undefined, undefined, undefined];
groupsOfSix[0] = s.charCodeAt(i) >> 2;
groupsOfSix[1] = (s.charCodeAt(i) & 0x03) << 4;
if (s.length > i + 1) {
groupsOfSix[1] |= s.charCodeAt(i + 1) >> 4;
groupsOfSix[2] = (s.charCodeAt(i + 1) & 0x0f) << 2;
}
if (s.length > i + 2) {
groupsOfSix[2] |= s.charCodeAt(i + 2) >> 6;
groupsOfSix[3] = s.charCodeAt(i + 2) & 0x3f;
}
for (var j = 0; j < groupsOfSix.length; j++) {
if (typeof groupsOfSix[j] == 'undefined') {
out += '=';
} else {
out += btoaLookup(groupsOfSix[j]);
}
}
}
return out;
}
/**
* Lookup table for btoa(), which converts a six-bit number into the
* corresponding ASCII character.
*/
function btoaLookup(idx) {
if (idx < 26) {
return String.fromCharCode(idx + 'A'.charCodeAt(0));
}
if (idx < 52) {
return String.fromCharCode(idx - 26 + 'a'.charCodeAt(0));
}
if (idx < 62) {
return String.fromCharCode(idx - 52 + '0'.charCodeAt(0));
}
if (idx == 62) {
return '+';
}
if (idx == 63) {
return '/';
}
// Throw INVALID_CHARACTER_ERR exception here -- won't be hit in the tests.
}
module.exports = btoa;
Version data entries
5 entries across 4 versions & 4 rubygems