mongodb 连接池

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  //MyMongo.js
  1 var mongodb = require('mongodb');
  2 
  3 function MyMongo(host, port, dbname) {
  4     this.host = host;
  5     this.port = port;
  6     this.dbname = dbname;                                                                                                                                                      
  7 
  8     this.server = new mongodb.Server(this.host,this.port,{auto_reconnect: true,safe:true});
  9 
 10     this.db_connector = new mongodb.Db(this.dbname, this.server,{safe:true});
        //加上{safe:true}之后就不会提示
        //Please ensure that you set the default write concern for the database by setting one of the options
 11 
 12     var self = this;
 13 
 14     this.db = undefined;
 15     this.queue = [];
 16 
 17     this.db_connector.open(function(err, db) {
 18         if( err ) {
 19             console.log(err);
 20             return;
 21         }
 22         self.db = db;
 23         for (var i = 0; i < self.queue.length; i++) {
 24             var collection = new mongodb.Collection(self.db, self.queue[i].cn);//cn  collectionName
 25             self.queue[i].cb(collection);
 26         }
 27         self.queue = [];
 28 
 29     });
 30 }
 31 exports.MyMongo = MyMongo;
 32 
 33 MyMongo.prototype.query = function(collectionName, callback) {
 34     if (this.db != undefined) {
 35         var collection = new mongodb.Collection(this.db, collectionName);
 36         callback(collection);
 37         return;
 38     }
 39     this.queue.push({ "cn" : collectionName, "cb" : callback});
 40 }
//config.js
  1 var mongo = require('./lib/MyMongo.js').MyMongo;                                                                                                                               
  2 
  3 var db = new mongo('localhost',27017,'operation');
  4 
  5 exports = module.exports = {
  6     db_name:'operation',
  7     db:db
  8 
  9 };
//use.js
 1 var config = require('config.js');
  2 
  3 var db = config.db;
  4 
  7 //nodejs下的col集合                                                                                                                                                       
  8 var COL = 'col';
  9 
 10 db.query(COL, function(collection) {
 11     collection.insert({a:1,b:2,c:3},function(err, docs) {
 12         console.log("First:\n", docs);
 13     });
 14 });
 15 
 16 
 17 db.query(COL, function(collection) {
 18     collection.find({}, {
 19         limit: 10
 20     }).toArray(function(err, docs) {
 21         console.log("\nSecond:\n", docs);
 22     });
 23 });
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