| /* |
| * 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.geode.cache; |
| |
| |
| /** |
| * Contains information about an event affecting an entry, including its identity and the the |
| * circumstances of the event. It is passed in to <code>CacheListener</code>, |
| * <code>CapacityController</code>, and <code>CacheWriter</code>. |
| * <p> |
| * If this event originated from a region stored off heap then this event can only be used as long |
| * as the notification method that obtained it has not returned. For example in your implementation |
| * of {@link CacheListener#afterUpdate(EntryEvent)} the event parameter is only valid until your |
| * afterUpdate method returns. It is not safe to store instances of this class and use them later |
| * when using off heap storage. Attempts to access off-heap data from this event after it has |
| * expired will result in an IllegalStateException. |
| * |
| * |
| * |
| * @see CacheListener |
| * @see CacheWriter |
| * @see RegionEvent |
| * @since GemFire 3.0 |
| */ |
| public interface EntryEvent<K, V> extends CacheEvent<K, V> { |
| |
| /** |
| * Returns the key. |
| * |
| * @return the key |
| */ |
| K getKey(); |
| |
| |
| /** |
| * Returns the value in the cache prior to this event. When passed to an event handler after an |
| * event occurs, this value reflects the value that was in the cache in this VM, not necessarily |
| * the value that was in the cache VM that initiated the operation. In certain scenarios the old |
| * value may no longer be available in which case <code>null</code> is returned. This can happen |
| * for disk regions when the old value is on disk only. |
| * |
| * @return the old value in the cache prior to this event. If the entry did not exist, was |
| * invalid, or was not available, then null is returned. |
| * @throws IllegalStateException if off-heap and called after the method that was passed this |
| * EntryEvent returns. |
| */ |
| V getOldValue(); |
| |
| /** |
| * Returns the serialized form of the value in the cache before this event. |
| * |
| * @return the serialized form of the value in the cache before this event |
| * @throws IllegalStateException if off-heap and called after the method that was passed this |
| * EntryEvent returns. |
| * |
| * @since GemFire 5.5 |
| */ |
| SerializedCacheValue<V> getSerializedOldValue(); |
| |
| /** |
| * Returns the value in the cache after this event. |
| * |
| * @return the value in the cache after this event |
| * @throws IllegalStateException if off-heap and called after the method that was passed this |
| * EntryEvent returns. |
| */ |
| V getNewValue(); |
| |
| /** |
| * Returns the serialized form of the value in the cache after this event. |
| * |
| * @return the serialized form of the value in the cache after this event |
| * @throws IllegalStateException if off-heap and called after the method that was passed this |
| * EntryEvent returns. |
| * |
| * @since GemFire 5.5 |
| */ |
| SerializedCacheValue<V> getSerializedNewValue(); |
| |
| /** |
| * Gets the TransactionId for this EntryEvent. |
| * |
| * @return the ID of the transaction that performed the operation that generated this event; null |
| * if no transaction involved. |
| * @since GemFire 4.0 |
| */ |
| TransactionId getTransactionId(); |
| |
| /** |
| * Returns true if this event originated on a client. |
| * |
| * @since GemFire 5.7 |
| * @return true if this event originated on a client. |
| */ |
| boolean hasClientOrigin(); |
| |
| /** |
| * Returns <code>true</code> if the old value is "available". Not available means that an old |
| * value existed but it could not be obtained or it was deemed too expensive to obtain. Note that |
| * {@link #getOldValue} will return <code>null</code> when this method returns <code>false</code>. |
| * |
| * @since GemFire 6.0 |
| */ |
| boolean isOldValueAvailable(); |
| } |