xunfeiAI/node_modules/base-64/base64.js

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2023-09-12 20:19:08 +08:00
/*! https://mths.be/base64 v1.0.0 by @mathias | MIT license */
;(function(root) {
// Detect free variables `exports`.
var freeExports = typeof exports == 'object' && exports;
// Detect free variable `module`.
var freeModule = typeof module == 'object' && module &&
module.exports == freeExports && module;
// Detect free variable `global`, from Node.js or Browserified code, and use
// it as `root`.
var freeGlobal = typeof global == 'object' && global;
if (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal) {
root = freeGlobal;
}
/*--------------------------------------------------------------------------*/
var InvalidCharacterError = function(message) {
this.message = message;
};
InvalidCharacterError.prototype = new Error;
InvalidCharacterError.prototype.name = 'InvalidCharacterError';
var error = function(message) {
// Note: the error messages used throughout this file match those used by
// the native `atob`/`btoa` implementation in Chromium.
throw new InvalidCharacterError(message);
};
var TABLE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
// http://whatwg.org/html/common-microsyntaxes.html#space-character
var REGEX_SPACE_CHARACTERS = /[\t\n\f\r ]/g;
// `decode` is designed to be fully compatible with `atob` as described in the
// HTML Standard. http://whatwg.org/html/webappapis.html#dom-windowbase64-atob
// The optimized base64-decoding algorithm used is based on @atks excellent
// implementation. https://gist.github.com/atk/1020396
var decode = function(input) {
input = String(input)
.replace(REGEX_SPACE_CHARACTERS, '');
var length = input.length;
if (length % 4 == 0) {
input = input.replace(/==?$/, '');
length = input.length;
}
if (
length % 4 == 1 ||
// http://whatwg.org/C#alphanumeric-ascii-characters
/[^+a-zA-Z0-9/]/.test(input)
) {
error(
'Invalid character: the string to be decoded is not correctly encoded.'
);
}
var bitCounter = 0;
var bitStorage;
var buffer;
var output = '';
var position = -1;
while (++position < length) {
buffer = TABLE.indexOf(input.charAt(position));
bitStorage = bitCounter % 4 ? bitStorage * 64 + buffer : buffer;
// Unless this is the first of a group of 4 characters…
if (bitCounter++ % 4) {
// …convert the first 8 bits to a single ASCII character.
output += String.fromCharCode(
0xFF & bitStorage >> (-2 * bitCounter & 6)
);
}
}
return output;
};
// `encode` is designed to be fully compatible with `btoa` as described in the
// HTML Standard: http://whatwg.org/html/webappapis.html#dom-windowbase64-btoa
var encode = function(input) {
input = String(input);
if (/[^\0-\xFF]/.test(input)) {
// Note: no need to special-case astral symbols here, as surrogates are
// matched, and the input is supposed to only contain ASCII anyway.
error(
'The string to be encoded contains characters outside of the ' +
'Latin1 range.'
);
}
var padding = input.length % 3;
var output = '';
var position = -1;
var a;
var b;
var c;
var buffer;
// Make sure any padding is handled outside of the loop.
var length = input.length - padding;
while (++position < length) {
// Read three bytes, i.e. 24 bits.
a = input.charCodeAt(position) << 16;
b = input.charCodeAt(++position) << 8;
c = input.charCodeAt(++position);
buffer = a + b + c;
// Turn the 24 bits into four chunks of 6 bits each, and append the
// matching character for each of them to the output.
output += (
TABLE.charAt(buffer >> 18 & 0x3F) +
TABLE.charAt(buffer >> 12 & 0x3F) +
TABLE.charAt(buffer >> 6 & 0x3F) +
TABLE.charAt(buffer & 0x3F)
);
}
if (padding == 2) {
a = input.charCodeAt(position) << 8;
b = input.charCodeAt(++position);
buffer = a + b;
output += (
TABLE.charAt(buffer >> 10) +
TABLE.charAt((buffer >> 4) & 0x3F) +
TABLE.charAt((buffer << 2) & 0x3F) +
'='
);
} else if (padding == 1) {
buffer = input.charCodeAt(position);
output += (
TABLE.charAt(buffer >> 2) +
TABLE.charAt((buffer << 4) & 0x3F) +
'=='
);
}
return output;
};
var base64 = {
'encode': encode,
'decode': decode,
'version': '1.0.0'
};
// Some AMD build optimizers, like r.js, check for specific condition patterns
// like the following:
if (
typeof define == 'function' &&
typeof define.amd == 'object' &&
define.amd
) {
define(function() {
return base64;
});
} else if (freeExports && !freeExports.nodeType) {
if (freeModule) { // in Node.js or RingoJS v0.8.0+
freeModule.exports = base64;
} else { // in Narwhal or RingoJS v0.7.0-
for (var key in base64) {
base64.hasOwnProperty(key) && (freeExports[key] = base64[key]);
}
}
} else { // in Rhino or a web browser
root.base64 = base64;
}
}(this));