javascript日期处理函数，性能优化批处理

(function(window) {  var sinojh = {    Version : "1.2",    Copyright : "Copyright© sino-jh 2012",    Author : "Jeff Lan",    Email : "jefflan@live.cn"  };  /**   * 方便于添加和重写类的属性   * @param {Object} attributes 添加的属性   */  Function.prototype.prototypes = function(attributes) {    for ( var a in attributes) {      this.prototype[a] = attributes[a];    }  };  /**   * 获取Url参数   * @param {String} parameter 参数名   * @return {String} 参数值   */  sinojh.getUrlParameter = function(parameter) {    if (!sinojh.getUrlParameter.cache) {      var url = window.location.href;      var paraString = url.substring(url.indexOf("?") + 1, url.length).split("&");      var cache = {};      for ( var i in paraString) {        var j = paraString[i];        cache[j.substring(0, j.indexOf("="))] = j.substring(j.indexOf("=") + 1, j.length);      }      sinojh.getUrlParameter.cache = cache;    }    return sinojh.getUrlParameter.cache[parameter];  };  /**   * 日期格式化   * @param {Date} date 日期对象   * @param {String} formatStyle 格式化样式   * @return {String} 日期型字符串   */  sinojh.dateFormat = function(date, formatStyle) {    formatStyle = formatStyle ? formatStyle : sinojh.dateFormat.settings.formatStyle;    var time = {      "M+" : date.getMonth() + 1,      "d+" : date.getDate(),      "h+" : date.getHours(),      "m+" : date.getMinutes(),      "s+" : date.getSeconds(),      "S" : date.getMilliseconds()    };    if (formatStyle == sinojh.dateFormat.formatStyleCache) {      var replaceCache = sinojh.dateFormat.replaceCache;      if (replaceCache["y+"]) {        formatStyle = formatStyle.replace(replaceCache["y+"].replace, (date.getFullYear() + "").substring(replaceCache["y+"].index));      }      for ( var k in time) {        if (replaceCache[k]) {          formatStyle = formatStyle.replace(replaceCache[k].replace, replaceCache[k].replace.length == 1 ? time[k] : ("00" + time[k]).substring(("" + time[k]).length));        }      }    } else {      sinojh.dateFormat.formatStyleCache = formatStyle;      var replaceCache = {};      if (new RegExp("(y+)").test(formatStyle)) {        var index = 4 - RegExp.$1.length;        replaceCache["y+"] = {          replace : RegExp.$1,          index : index        };        formatStyle = formatStyle.replace(RegExp.$1, (date.getFullYear() + "").substring(index));      }      for ( var k in time) {        if (new RegExp("(" + k + ")").test(formatStyle)) {          replaceCache[k] = {            replace : RegExp.$1          };          formatStyle = formatStyle.replace(RegExp.$1, RegExp.$1.length == 1 ? time[k] : ("00" + time[k]).substring(("" + time[k]).length));        }      }      sinojh.dateFormat.replaceCache = replaceCache;    }    return formatStyle;  };  sinojh.dateFormat.settings = {    formatStyle : "yyyy-MM-dd hh:mm:ss"  };  /**   * 将日期格式的字符串转换成Date对象   * @param {String} dateStr 日期格式字符串   * @param {String} dateStyle 日期格式   * @return {Date} 日期对象   */  sinojh.toDate = function(dateStr, dateStyle) {    dateStyle = dateStyle ? dateStyle : sinojh.toDate.settings.dateStyle;    var compare = sinojh.toDate.compare;    var result = new sinojh.toDate.result();    if (dateStyle == sinojh.toDate.settings.dateStyleCache) {      var indexCache = sinojh.toDate.indexCache;      for ( var k in compare) {        if (indexCache[k]) {          result[compare[k]] = dateStr.substring(indexCache[k].index, indexCache[k].index + indexCache[k].length);        }      }    } else {      var indexCache = {};      for ( var k in compare) {        if (new RegExp("(" + k + ")").test(dateStyle)) {          var index = dateStyle.indexOf(RegExp.$1);          var length = RegExp.$1.length;          indexCache[k] = {            index : index,            length : length          };          result[compare[k]] = dateStr.substring(index, index + length);        }      }      sinojh.toDate.indexCache = indexCache;      sinojh.toDate.settings.dateStyleCache = dateStyle;    }    return new Date(result["y"], result["M"] - 1, result["d"], result["h"], result["m"], result["s"], result["S"]);  };  sinojh.toDate.compare = {    "y+" : "y",    "M+" : "M",    "d+" : "d",    "h+" : "h",    "m+" : "m",    "s+" : "s",    "S" : "S"  };  sinojh.toDate.result = function() {  };  sinojh.toDate.result.prototypes( {    "y" : "",    "M" : "",    "d" : "",    "h" : "00",    "m" : "00",    "s" : "00",    "S" : "000"  });  sinojh.toDate.settings = {    dateStyle : "yyyy-MM-dd hh:mm:ss"  };  delete Function.prototype.prototypes;  window.jh = sinojh;}(this);