| package org.apache.cassandra.triggers; |
| /* |
| * |
| * 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. |
| * |
| */ |
| |
| |
| import java.nio.ByteBuffer; |
| import java.util.Collection; |
| |
| import org.apache.cassandra.db.Mutation; |
| import org.apache.cassandra.db.partitions.Partition; |
| |
| /** |
| * Trigger interface, For every partition update received by the coordinator {@link #augment(Partition)} |
| * is called.<p> |
| * |
| * <b> Contract:</b><br> |
| * 1) Implementation of this interface should only have a constructor without parameters <br> |
| * 2) ITrigger implementation can be instantiated multiple times during the server life time. |
| * (Depends on the number of times trigger folder is updated.)<br> |
| * 3) ITrigger implementation should be state-less (avoid dependency on instance variables).<br> |
| * |
| * <br><b>The API is still beta and can change.</b> |
| */ |
| public interface ITrigger |
| { |
| /** |
| * Called exactly once per CF update, returned mutations are atomically updated. |
| * |
| * @param update - update received for the CF |
| * @return additional modifications to be applied along with the supplied update |
| */ |
| public Collection<Mutation> augment(Partition update); |
| } |