计算新浪Weibo消息长度(还可以输入119字)

var getMessageLength = (function() {
var byteLength = function(b) {
if(typeof b == "undefined") {
return 0;
}
var a = b.match(/[^/x00-/x80]/g);
return(b.length + (!a ? 0 : a.length));
};
return function(message) {
message = message || '';
message = message.replace(//r/n/g, "/n");
var c = 41,
d = 140,
e = 20,
f = message,
g = message.match(/http:////[a-zA-Z0-9]+(/.[a-zA-Z0-9]+)+([-A-Z0-9a-z_/$/./+/!/*/(/)//,:;@&=/?/~/#/%]*)*/gi) || [],
h = 0;

for(var i = 0, j = g.length; i < j; i++) {
var k = byteLength(g[i]);
if(/^(http:////t.cn)/.test(g[i])) {
continue;
}
/^(http:////)+(t.sina.com.cn|t.sina.cn)/.test(g[i]) || /^(http:////)+(weibo.com|weibo.cn)/.test(g[i]) ? h += k <= c ? k : k <= d ? e : k - d + e : h += k <= d ? e : k - d + e;
f = f.replace(g[i], "");
}
var l = Math.ceil((h + byteLength(f)) / 2);
return l;
};
})();