Javascript UUID

代码来自“美篇”。

function UUID(){
    this.id = this.createUUID();
}
UUID.prototype.valueOf = function(){ return this.id; };
UUID.prototype.toString = function(){ return this.id; };
UUID.prototype.createUUID = function(){
    var dg = new Date(1582, 10, 15, 0, 0, 0, 0);
    var dc = new Date();
    var t = dc.getTime() - dg.getTime();
    var tl = UUID.getIntegerBits(t,0,31);
    var tm = UUID.getIntegerBits(t,32,47);
    var thv = UUID.getIntegerBits(t,48,59) + '1'; // version 1, security version is 2
    var csar = UUID.getIntegerBits(UUID.rand(4095),0,7);
    var csl = UUID.getIntegerBits(UUID.rand(4095),0,7);
    var n = UUID.getIntegerBits(UUID.rand(8191),0,7) +
            UUID.getIntegerBits(UUID.rand(8191),8,15) +
            UUID.getIntegerBits(UUID.rand(8191),0,7) +
            UUID.getIntegerBits(UUID.rand(8191),8,15) +
            UUID.getIntegerBits(UUID.rand(8191),0,15); // this last number is two octets long
    return tl + tm  + thv  + csar + csl + n;
};
UUID.getIntegerBits = function(val,start,end){
    var base16 = UUID.returnBase(val,16);
    var quadArray = [];
    var quadString = '';
    for(i=0;i< base16.length;i++){
        quadArray.push(base16.substring(i,i+1));  
    }
    for(i=Math.floor(start/4);i<=Math.floor(end/4);i++){
        if(!quadArray[i] || quadArray[i] == '') quadString += '0';
        else quadString += quadArray[i];
    }
    return quadString;
};
UUID.returnBase = function(number, base){
    return (number).toString(base).toUpperCase();
};
UUID.rand = function(max){
    return Math.floor(Math.random() * (max + 1));
};