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/*
 * Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
 *
 * Licensed 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. See accompanying
 * LICENSE file.
 */

package com.gemstone.gemfire.internal.cache;

import com.gemstone.gemfire.internal.DataSerializableFixedID;

/**
 * Interface that can be implemented by region keys to allow passing the region
 * after deserialization for any region specific initialization. Note that the
 * {@link LocalRegion#setKeyRequiresRegionContext(boolean)} should also be set
 * for {@link #setRegionContext(LocalRegion)} to be invoked by the GemFire
 * layer. It is required that either all keys of the region implement this
 * interface (and the flag
 * {@link LocalRegion#setKeyRequiresRegionContext(boolean)} is set) or none do.
 * 
 * Currently used by GemFireXD for the optimized
 * CompactCompositeRegionKey key implementations that keeps the key
 * as a reference to the raw row bytes and requires a handle of the table schema
 * to interpret those in hashCode/equals/compareTo methods that have no region
 * context information.
 * 
 * @author swale
 */
public interface KeyWithRegionContext extends DataSerializableFixedID {

  /**
   * Pass the region of the key for setting up of any region specific context
   * for the key. In case of recovery from disk the region may not have been
   * fully initialized yet, so the implementation needs to take that into
   * consideration.
   * 
   * @param region
   *          the region of this key
   */
  public void setRegionContext(LocalRegion region);

  /**
   * Changes required to be done to the key, if any, to optimize serialization
   * for sending across when value is also available.
   * 
   * GemFireXD will make the value bytes as null in the key so as to avoid
   * serializing the row twice.
   */
  public KeyWithRegionContext beforeSerializationWithValue(boolean valueIsToken);

  /**
   * Changes required to be done to the key, if any, to after deserializing the
   * key in reply with value available. The value is required to be provided in
   * deserialized format (e.g. for {@link CachedDeserializable}s the
   * deserialized value being wrapped must be passed). This should always be
   * invoked before {@link #setRegionContext(LocalRegion)} to set the meta-data
   * from value correctly.
   * 
   * GemFireXD will restore the value bytes that were set as null in
   * {@link #beforeSerializationWithValue}.
   */
  public void afterDeserializationWithValue(Object val);
}