DirectIndexInputCache.java

/**
 * 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.blur.store.blockcache_v2;

import java.util.concurrent.atomic.AtomicReferenceArray;

public class DirectIndexInputCache extends IndexInputCache {

  private final AtomicReferenceArray<CacheValue> _cacheValues;

  public DirectIndexInputCache(long fileLength, int cacheBlockSize, MeterWrapper hits) {
    super(fileLength, cacheBlockSize, hits);
    int indexLength = (int) (fileLength / cacheBlockSize);
    if (fileLength % cacheBlockSize != 0) {
      indexLength++;
    }
    _cacheValues = new AtomicReferenceArray<CacheValue>(indexLength);
  }

  @Override
  public void put(long blockId, CacheValue cacheValue) {
    _cacheValues.set((int) blockId, cacheValue);
  }

  @Override
  public CacheValue get(long blockId) {
    int id = (int) blockId;
    CacheValue cacheValue = _cacheValues.get(id);
    if (cacheValue == null) {
      return null;
    } else if (cacheValue.isEvicted()) {
      _cacheValues.compareAndSet(id, cacheValue, null);
      return null;
    }
    return cacheValue;
  }
}