MYSQL切断時にリトライするモジュール

mysql_client.js

var mysql = require('mysql');
var DefaultEvent = {
    onConnected : function(){
        console.log('MYSQL[%s] connected', this.conf.host);
    },
    onClosed : function(reason){
        console.log('MYSQL[%s] closed reason: %s', this.conf.host, reason);
    },
    onError : function(err){
        console.log(err.stack);
    },
    onQuery : function(sql){
        console.log('MYSQL[%s] query: %s', this.conf.host, sql);
    },
    doReconnect : function(err){
        console.log('MYSQL[%s] re-connecting lost connection: %s', this.conf.host, err.code);
        return true;
    },
};
var mysqlCreateConnect = function(ref) {
    var conn = ref.conn = mysql.createConnection(ref.conf);
    conn.on('end', function(err){
        var reason = "APP_CLOSE";
        if(err){
            reason = err.code;
        }
        ref.event.onClosed.bind(ref)(reason);
    });
    conn.on('error', function(err) {
        if (!err.fatal) {
            return;
        }
        if (err.code !== 'PROTOCOL_CONNECTION_LOST') {
            throw err;
        }
        if(ref.isConnect && ref.event.doReconnect.bind(ref)(err)){
            mysqlCreateConnect(ref);
        }
    });
    conn.connect(function(err){
        if(err){
            switch(err.errno){
            case "ECONNREFUSED":
                mysqlCreateConnect(ref);
                break;
            case "ENOTFOUND":
                ref.event.onError.bind(ref)(err);
                break;
            }
        }else{
            ref.event.onConnected.bind(ref)();
        }
    });
}
var MysqlClient = module.exports = function(conf, event){
    if(!event){
        event = DefaultEvent;
    }
    this.conn = null;
    this.isConnect = false;
    this.event = event;
    this.conf = conf;
};
MysqlClient.prototype = {
    connect : function(){
        if(this.isConnect){
            return;
        }
        this.isConnect = true;
        mysqlCreateConnect(this);
    },
    close : function(){
        if(this.isConnect){
            this.isConnect = false;
            this.conn.end();
        }
    },
    query : function(sql, arg1, arg2){
        var log = sql;
        if(!(arg1 instanceof Function)){
            if(arg1 instanceof Array){
                arg1.forEach(function(v){
                    log = log.replace('?', '"'+v.toString()+'"');
                });
            }else{
                log = log.replace('?', '"'+arg1.toString()+'"');
            }
        }
        this.event.onQuery.bind(this)(log);
        this.conn.query(sql, arg1, arg2);
    },
};

test.js

var MysqlClient = require("./mysql_client.js");
function test(){
    var conf = {
        host : "127.0.0.1",
        user : "root",
        database : "test",
    };
    var cl = new MysqlClient(conf);
    cl.connect();
    setTimeout(function T(){
        cl.query('select * from test1 where id = ?;',[Math.random()*100|0],function(err,val){
            console.log(val);
        });
        setTimeout(T, Math.random()*12000|0);
    }, 0);
}
test();