/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.accumulo.core.iteratorsImpl.system;

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

import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Range;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.iterators.SortedKeyValueIterator;

/**
 * An iterator capable of iterating over other iterators in sorted order while shuffling the initial
 * seek ordering to avoid thread contention.
 */
public class MultiShuffledIterator extends MultiIterator {

  public MultiShuffledIterator(List<SortedKeyValueIterator<Key,Value>> readers) {
    super(readers);
  }

  public MultiShuffledIterator(List<SortedKeyValueIterator<Key,Value>> iters, Range seekFence) {
    super(iters, seekFence);
  }

  public MultiShuffledIterator(List<SortedKeyValueIterator<Key,Value>> readers, boolean init) {
    super(readers, init);
  }

  @Override
  protected void setIters(List<SortedKeyValueIterator<Key,Value>> iters) {
    var copy = new ArrayList<>(iters);
    Collections.shuffle(copy);
    super.setIters(copy);
  }
}
