CappedObject for Nic

capped-object.js

var CappedObject = function( limit ){
  items   = {};
  length  = 0 ;
  this.put = function( string ) {   
    if( items[string] ) return string;
    items[string] = string;
    length++;
    if( length > limit ){
      delete items[ Object.keys( items )[0]];
      length --;
    };
    return string;
  };
  this.has = function( string ) {
    return Boolean( items[string] );
  };
  this.getLength = function() {
    return length
  };
  this.getItems = function() {
    return Object.keys( items )
  }
  return this;
};

/* Usage */

var cache = new CappedObject( 2 );

cache.put( "Bleh Bleh")
console.log( cache.getLength())
cache.put( "Mah Mah")
console.log( cache.getLength())
cache.put( "Ooo Ooo")
console.log( cache.getLength())
cache.put( "Bleh Ooo")
console.log( cache.getLength())

console.log( cache.getItems())