/** * 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 com.twitter.distributedlog.service.stream; import com.google.common.base.Stopwatch; import com.twitter.distributedlog.AsyncLogWriter; import com.twitter.distributedlog.exceptions.DLException; import com.twitter.distributedlog.thrift.service.ResponseHeader; import com.twitter.distributedlog.util.Sequencer; import com.twitter.util.Future; import java.nio.ByteBuffer; /** * An operation applied to a stream. */ public interface StreamOp { /** * Execute a stream op with the supplied writer. * * @param writer active writer for applying the change * @param sequencer sequencer used for generating transaction id for stream operations * @param txnLock transaction lock to guarantee ordering of transaction id * @return a future satisfied when the operation completes execution */ Future<Void> execute(AsyncLogWriter writer, Sequencer sequencer, Object txnLock); /** * Invoked before the stream op is executed. */ void preExecute() throws DLException; /** * Return the response header (containing the status code etc.). * * @return A future containing the response header or the exception * encountered by the op if it failed. */ Future<ResponseHeader> responseHeader(); /** * Abort the operation with the givem exception. */ void fail(Throwable t); /** * Return the stream name. */ String streamName(); /** * Stopwatch gives the start time of the operation. */ Stopwatch stopwatch(); /** * Compute checksum from arguments. */ Long computeChecksum(); }