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/**
* jQuery.byteLength
*
* Calculate the byte length of a string (accounting for UTF-8).
*
* @author Jan Paul Posma, 2011
* @author Timo Tijhof, 2012
* @author David Chan, 2013
*/
jQuery.byteLength = function ( str ) {
// This basically figures out how many bytes a UTF-16 string (which is what js sees)
// will take in UTF-8 by replacing a 2 byte character with 2 *'s, etc, and counting that.
// Note, surrogate (\uD800-\uDFFF) characters are counted as 2 bytes, since there's two of them
// and the actual character takes 4 bytes in UTF-8 (2*2=4). Might not work perfectly in
// edge cases such as illegal sequences, but that should never happen.
// https://en.wikipedia.org/wiki/UTF-8#Description
// The mapping from UTF-16 code units to UTF-8 bytes is as follows:
// > Range 0000-007F: codepoints that become 1 byte of UTF-8
// > Range 0080-07FF: codepoints that become 2 bytes of UTF-8
// > Range 0800-D7FF: codepoints that become 3 bytes of UTF-8
// > Range D800-DFFF: Surrogates (each pair becomes 4 bytes of UTF-8)
// > Range E000-FFFF: codepoints that become 3 bytes of UTF-8 (continued)
return str
.replace( /[\u0080-\u07FF\uD800-\uDFFF]/g, '**' )
.replace( /[\u0800-\uD7FF\uE000-\uFFFF]/g, '***' )
.length;
};
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