nodejs 封装自己的log模块

var fs = require("fs");function fix2num(n) {    return [0, n].join('').slice(-2);}function getTime(format) {    var curdate = new Date();    if (format == undefined) return curdate;    format = format.replace(/Y/i, curdate.getFullYear());    format = format.replace(/m/i, fix2num(curdate.getMonth() + 1));    format = format.replace(/d/i, fix2num(curdate.getDate()));    format = format.replace(/H/i, fix2num(curdate.getHours()));    format = format.replace(/i/i, fix2num(curdate.getMinutes()));    format = format.replace(/s/i, fix2num(curdate.getSeconds()));    format = format.replace(/ms/i, curdate.getMilliseconds());    return format;}var options = {    logLevel: {        debug: true,        error: true,        warn: true,        info: true    },    consoleLevel: {        debug: true,        error: true,        warn: true,        info: true    },    buffer: {        interval: 1000,        tag: true    },    path: './',    timeFormat: 'Ymd',    file: 'log',    format: 'time: [file] content'};var consoleColorTag = {    "error_prefix": "\u001B[31m",    "error_suffix": "\u001B[39m",    "warn_prefix": "\u001B[32m",    "warn_suffix": "\u001B[39m",    "info_prefix": "\u001B[1m",    "info_suffix": "\u001B[22m",    "debug_prefix": "\u001B[35m",    "debug_suffix": "\u001B[39m"};function Log(options) {    this.options = options;    this.buf = [];    if (this.options.buffer.tag) {        var self = this;        setInterval(function () {            if (self.buf.length) {                for (var i = 0, len = self.buf.length; i < len; ++i) {                    self.write(self.buf[i][0], self.buf[i][1]);                }                self.buf.length = 0;            }        }, self.options.buffer.interval);    }}Log.prototype.debug = function (str) {    this._log("debug", str);};Log.prototype.error = function (str) {    this._log("error", str);};Log.prototype.warn = function (str) {    this._log("warn", str);};Log.prototype.info = function (str) {    this._log("info", str);};Log.prototype.write = function (level, str) {    if (str) {        fs.appendFile(this.getFilename(level), str, {flat: 'a'});    }};Log.prototype.console = function (l, str) {    if (this.options.consoleLevel[l]) {        var l = l.toLowerCase();        var lPrefix = consoleColorTag[l + "_prefix"];        var lSuffix = consoleColorTag[l + "_suffix"];        var cStr = [lPrefix, getTime("Y-m-d h:i:s"), "[", l, "]", "[", this.options.file, "]", str, lSuffix, "\n"].join("");        console.log(cStr);    }};Log.prototype._log = function (level, str) {    var fStr = [getTime("Y-m-d h:i:s"), "[", this.options.file, "]", str, "\n"].join("");    if (!this.options.buffer.tag) {        this.write(level, fStr);    } else {        this.buf.push([level, fStr]);    }    this.console(level, str);};Log.prototype.getFilename = function (level) {    var format = getTime(this.options.timeFormat);    return [this.options.path, level, this.options.file, format, '.log'].join('');};var logs = new Log(options);logs.debug("haha");logs.warn("haha");logs.info("haha");logs.error("haha");