synchServerTime.js

/**
 * [synchServerTime   弱心跳渐强同步服务器时间]
 * @author ThomasChan
 * @param  {int}      beginTime   [当前时间]
 * @param  {int}      endTime     [结束时间]
 * @param  {function} iterator    [每次同步完时间要做的事]
 * @return
 * @usage 
 *  synchServerTime(
 *      +new Date()
 *      ,+new Date() + 3600
 *      ,function(){ console.log(this.timeNow) }
 *  );
 *  this will console 5 times timestamp
 */
synchServerTime = function( beginTime, endTime, iterator ) {
    var
    obj = {
        'timePublish' : endTime
        ,'timeNow' : beginTime
    }
    ,timeGap = function() { return obj.timePublish - obj.timeNow }
    ,timeSynch = function( callbacks ) { itz.getTimeStamp(function( d ) { obj.timeNow = d.data,callbacks(); }.bind( obj )) }
    // ,timeSynch = function( callbacks ) { /*ajax get server time && exec callbacks*/ }
    ,timerFn = function(){
        var timer = setTimeout( function() {
            clearTimeout(timer)
            ,timeSynch( function() {
                iterator.call(obj)
                ,reSynch()
            })
        } ,timeGap() * 500 )
    }
    ,reSynch = function() { timeGap() >= 10 && timerFn() };
    reSynch();
}