Java tutorial
/* * 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.omid.tso; import com.google.common.util.concurrent.ThreadFactoryBuilder; import com.google.inject.Inject; import org.apache.omid.committable.CommitTable; import org.apache.omid.metrics.MetricsRegistry; import org.apache.omid.metrics.Timer; import java.io.IOException; import java.util.concurrent.Callable; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import static org.apache.omid.metrics.MetricsUtils.name; public class LowWatermarkWriterImpl implements LowWatermarkWriter { private static final Logger LOG = LoggerFactory.getLogger(LowWatermarkWriterImpl.class); private final Timer lwmWriteTimer; private final CommitTable.Writer lowWatermarkWriter; private final ExecutorService lowWatermarkWriterExecutor; private MetricsRegistry metrics; @Inject LowWatermarkWriterImpl(TSOServerConfig config, CommitTable commitTable, MetricsRegistry metrics) throws Exception { this.metrics = metrics; this.lowWatermarkWriter = commitTable.getWriter(); // Low Watermark writer ThreadFactoryBuilder lwmThreadFactory = new ThreadFactoryBuilder().setNameFormat("lwm-writer-%d"); this.lowWatermarkWriterExecutor = Executors.newSingleThreadExecutor(lwmThreadFactory.build()); // Metrics config this.lwmWriteTimer = metrics.timer(name("tso", "lwmWriter", "latency")); LOG.info("PersistentProcessor initialized"); } @Override public Future<Void> persistLowWatermark(final long lowWatermark) { return lowWatermarkWriterExecutor.submit(new Callable<Void>() { @Override public Void call() throws IOException { try { lwmWriteTimer.start(); lowWatermarkWriter.updateLowWatermark(lowWatermark); lowWatermarkWriter.flush(); } finally { lwmWriteTimer.stop(); } return null; } }); } }