a-results.js

// Find: id-127948013911961470649950206280740122937131673124230331368744372

// Array
{ id: 'id-127948013911961470649950206280740122937131673124230331368744372'
, name: 'mape-id-127948013911961470649950206280740122937131673124230331368744372'
}
// Fetch using array: 30ms

// Object
{ name: 'mape-id-127948013911961470649950206280740122937131673124230331368744372' }
// Fetch using object: 0ms

// Manager
id-127948013911961470649950206280740122937131673124230331368744372
// Fetch using manager: 33ms

bench.js

console.timeStore = {};
console.time = function(str)
{
  console.timeStore[str] = new Date().getTime();
};
console.timeEnd = function(str)
{
  var diff = new Date().getTime()-console.timeStore[str];
  console.log(str+': '+diff+'ms');
};

/*-----------------------------------------------
  Connection Manager
-----------------------------------------------*/
function Manager(){
  this._head = null;
  this._tail = null;
  this._length = 0;
};

Object.defineProperty(Manager.prototype, "length", {
  get: function(){
    return this._length;
  }
});


Manager.prototype.attach = function(id, client){
  var connection = {
    id:     id,
    _next:  null,
    client: client
  };
  
  if(this._length == 0) {
    this._head = connection;
    this._tail = connection;
  } else {
    this._tail._next = connection;
    this._tail = connection;
  }
  
  ++this._length;
  };

Manager.prototype.detach = function(id, callback){
  var previous = current = this._head;
  
  while(current !== null){
    if(current.id === id){
      previous._next = current._next;
      this._length--;
      
      if(current.id === this._head.id){
        this._head = current._next;
      }
      if(current.id === this._tail.id){
        this._tail = previous;
      }
      
      break;
    } else {
      previous = current;
      current = current._next;
    }
  }
  
  delete current, previous;
  
  callback();
};

Manager.prototype.find = function(id, callback){
  var current = this._head;
  
  while(current !== null){
    if(current.id === id){
      callback(current.id);
      break;
    } else {
      current = current._next;
    }
  }
};

Manager.prototype.forEach = function(callback){
  var current = this._head;
  
  while(current !== null){
    callback(current.client);
    current = current._next;
  }
};


var man = new Manager();

var userIds = [];

// Create dummy ids
for (var i=0; i < 1000000; i++) {
  userIds.push('id-'+new Date().getTime()+Math.random()*100000000000000000+''+(Math.random()*100000000000000000)+''+(Math.random()*100000000000000000));
};

// Populate array with ids and users attached
var usersArr = []
for (var i=0,l=userIds.length; i < l; i++) {
  usersArr.push({
    'id': userIds[i]
    , 'name': 'mape-'+userIds[i]
  });
};

// Populate object with ids and users attached
var usersObj = []
for (var i=0,l=userIds.length; i < l; i++) {
  usersObj[userIds[i]] = {
    'name': 'mape-'+userIds[i]
  }
};

// Populate manager with ids and users attached
for (var i=0,l=userIds.length; i < l; i++) {
  man.attach(userIds[i], {
    'name': 'mape-'+userIds[i]
  });
};

// Generate an id to find
var randomId = userIds[Math.floor(Math.random()*userIds.length)];

console.log('\033[33m\nFind: '+randomId+'\033[39m');
console.log('\033[31m\nArray\033[39m');
console.time('Fetch using array')
for (var i=0,l=userIds.length; i < l; i++) {
  if (usersArr[i].id === randomId)
  {
    console.dir(usersArr[i]);
    break;
  }
};
console.timeEnd('Fetch using array')

console.time('Fetch using object')
console.log('\033[31m\nObject\033[39m');
console.dir(usersObj[randomId]);
console.timeEnd('Fetch using object')

console.time('Fetch using manager')
console.log('\033[31m\nManager\033[39m');
man.find(randomId, function(id){console.log(id);})
console.timeEnd('Fetch using manager')