mongo fd test

mongofdtest.js

var MongoClient = require('mongodb').MongoClient;
var mongoUri = "mongodb://192.168.11.2:27017/hoge";

function mapM(fs, cb) {
  var xs = [];
  function _mapM(fs, cb) {
    var f = fs.shift();
    f(function(x) {
      xs.push(x);
      if (fs.length == 0) {
        cb(xs);
      } else {
        _mapM(fs, cb);
      }
    });
  }
  _mapM(fs, cb);
}

function connectDB(cb) {
  MongoClient.connect(mongoUri, function(err, db) {
    cb({err: err, db: db});
  });                
}
var fs = [];
var max = 500;
for (var i = 0; i < max; i++) {
  fs.push(connectDB);
  //fs.push(function(f) { f(i); }); // debug
}

mapM(fs, function(results) {
  var succeeded = 0;
  var failed = 0;

  console.log('done');
  require('fs').readFileSync('/dev/stdin', 'utf8'); // press Ctrl-D to quit 

  for (var i = 0; i < max; i++) {
    var db = results[i].db;
    var err = results[i].err;
    if (db) { db.close(); succeeded++; }
    if (err) { console.log(err); failed++; }
  }

  console.log("succeeded: " + succeeded + ", failed: " + failed + ".");
});