/******************************************************************************* * Copyright 2011 Netflix * * 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. ******************************************************************************/ package com.netflix.astyanax.connectionpool; import java.math.BigInteger; import com.netflix.astyanax.connectionpool.exceptions.ConnectionException; import com.netflix.astyanax.connectionpool.exceptions.OperationException; /** * Callback interface to perform an operation on a client associated with a * connection pool's connection resource * * @author elandau * * @param <C> * @param <R> */ public interface Operation<CL, R> { /** * Execute the operation on the client object and return the results * * @param client * @return * @throws OperationException * @throws NetflixCassandraException */ R execute(CL client) throws ConnectionException; /** * Return the unique key on which the operation is performed or null if the * operation is performed on multiple keys. * * @return */ BigInteger getToken(); /** * Return keyspace for this operation. Return null if using the current * keyspace, or a keyspace is not needed for the operation. * * @return */ String getKeyspace(); /** * Return the host to run on or null to select a host using the load * blancer. Failover is disabled for this scenario. * * @param host * @return */ Host getPinnedHost(); }