/**
 * This software is licensed to you under the Apache License, Version 2.0 (the
 * "Apache License").
 *
 * LinkedIn's contributions are made under the Apache License. If you contribute
 * to the Software, the contributions will be deemed to have been made under the
 * Apache License, unless you expressly indicate otherwise. Please do not make any
 * contributions that would be inconsistent with the Apache License.
 *
 * You may obtain a copy of the Apache License at http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, this software
 * distributed under the Apache License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the Apache
 * License for the specific language governing permissions and limitations for the
 * software governed under the Apache License.
 *
 * © 2012 LinkedIn Corp. All Rights Reserved.  
 */
package com.senseidb.indexing.activity;

import java.util.ArrayList;
import java.util.List;

/**
 * Keeps track of all the changes not yet persisted
 * @author vzhabiuk
 *
 * @param <T>
 */
public class UpdateBatch<T> {
  int batchSize = 50000;
  protected volatile List<T> updates = new ArrayList<T>(2000);
  long delay = 15 * 1000;
  long time = System.currentTimeMillis();
  private UpdateBatch() {
  }
  public UpdateBatch(ActivityConfig activityConfig) {
    batchSize = activityConfig.getFlushBufferSize();
    delay = activityConfig.getFlushBufferMaxDelayInSeconds() * 1000;
  }
  public boolean addFieldUpdate(T fieldUpdate) {
    updates.add(fieldUpdate);
    if (flushNeeded()) {
      return true;
    }
    return false;
  }
  public boolean flushNeeded() {
    return updates.size() >= batchSize || ((System.currentTimeMillis() - time) > delay && !updates.isEmpty());
  }
  public List<T> getUpdates() {
    return updates;
  }
}