/*
 * 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
 *
 *     http://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.iterators.system;

import java.io.IOException;
import java.util.Collection;
import java.util.concurrent.atomic.AtomicLong;

import org.apache.accumulo.core.data.ByteSequence;
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.IteratorEnvironment;
import org.apache.accumulo.core.iterators.ServerWrappingIterator;
import org.apache.accumulo.core.iterators.SortedKeyValueIterator;

/**
 *
 */
public class StatsIterator extends ServerWrappingIterator {

  private int numRead = 0;
  private AtomicLong seekCounter;
  private AtomicLong readCounter;

  public StatsIterator(SortedKeyValueIterator<Key,Value> source, AtomicLong seekCounter, AtomicLong readCounter) {
    super(source);
    this.seekCounter = seekCounter;
    this.readCounter = readCounter;
  }

  @Override
  public void next() throws IOException {
    source.next();
    numRead++;

    if (numRead % 23 == 0) {
      readCounter.addAndGet(numRead);
      numRead = 0;
    }
  }

  @Override
  public SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment env) {
    return new StatsIterator(source.deepCopy(env), seekCounter, readCounter);
  }

  @Override
  public void seek(Range range, Collection<ByteSequence> columnFamilies, boolean inclusive) throws IOException {
    source.seek(range, columnFamilies, inclusive);
    seekCounter.incrementAndGet();
    readCounter.addAndGet(numRead);
    numRead = 0;
  }

  public void report() {
    readCounter.addAndGet(numRead);
    numRead = 0;
  }
}