/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2010 Sun Microsystems, Inc.
 */

package org.opends.sdk;



import com.sun.opends.sdk.util.CompletedFutureResult;
import com.sun.opends.sdk.util.Validator;



/**
 * A load balancing connection factory allocates connections using the provided
 * algorithm.
 */
final class LoadBalancer extends AbstractConnectionFactory
{
  private final LoadBalancingAlgorithm algorithm;



  /**
   * Creates a new load balancer using the provided algorithm.
   *
   * @param algorithm
   *          The load balancing algorithm which will be used to obtain the next
   *          connection factory.
   */
  public LoadBalancer(final LoadBalancingAlgorithm algorithm)
  {
    Validator.ensureNotNull(algorithm);
    this.algorithm = algorithm;
  }



  /**
   * {@inheritDoc}
   */
  @Override
  public FutureResult<AsynchronousConnection> getAsynchronousConnection(
      final ResultHandler<? super AsynchronousConnection> resultHandler)
  {
    final ConnectionFactory factory;

    try
    {
      factory = algorithm.getConnectionFactory();
    }
    catch (final ErrorResultException e)
    {
      if (resultHandler != null)
      {
        resultHandler.handleErrorResult(e);
      }
      return new CompletedFutureResult<AsynchronousConnection>(e);
    }

    return factory.getAsynchronousConnection(resultHandler);
  }



  /**
   * {@inheritDoc}
   */
  public String toString()
  {
    final StringBuilder builder = new StringBuilder();
    builder.append("LoadBalancer(");
    builder.append(String.valueOf(algorithm));
    builder.append(')');
    return builder.toString();
  }
}