content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.metrics.sink;
  
  import alluxio.metrics.MetricsSystem;
  
  import com.codahale.metrics.MetricRegistry;
  import com.codahale.metrics.graphite.Graphite;
  import com.codahale.metrics.graphite.GraphiteReporter;
  
  import java.util.Properties;
  import java.util.concurrent.TimeUnit;
  import javax.annotation.concurrent.ThreadSafe;
  
  /**
   * A sink which publishes metric values to a Graphite server.
   */
  @ThreadSafe
  public class GraphiteSink implements Sink {
    private static final int GRAPHITE_DEFAULT_PERIOD = 10;
    private static final String GRAPHITE_DEFAULT_UNIT = "SECONDS";
    private static final String GRAPHITE_DEFAULT_PREFIX = "";
  
    private static final String GRAPHITE_KEY_HOST = "host";
    private static final String GRAPHITE_KEY_PORT = "port";
    private static final String GRAPHITE_KEY_PERIOD = "period";
    private static final String GRAPHITE_KEY_UNIT = "unit";
    private static final String GRAPHITE_KEY_PREFIX = "prefix";
  
    private GraphiteReporter mReporter;
    private Properties mProperties;
  
    /**
     * Creates a new {@link GraphiteSink} with a {@link Properties} and {@link MetricRegistry}.
     *
     * @param properties the properties which may contain polling period and unit properties
     * @param registry the metric registry to register
     * @throws IllegalArgumentException if the {@code host} or {@code port} property is missing
     */
    public GraphiteSink(Properties properties, MetricRegistry registry)
        throws IllegalArgumentException {
      mProperties = properties;
      String host = properties.getProperty(GRAPHITE_KEY_HOST);
      String port = properties.getProperty(GRAPHITE_KEY_PORT);
      if (host == null || port == null) {
        throw new IllegalArgumentException("Graphite sink requires 'host' and 'port' properties");
      }
      String prefix = properties.getProperty(GRAPHITE_KEY_PREFIX);
      if (prefix == null) {
        prefix = GRAPHITE_DEFAULT_PREFIX;
      }
      Graphite graphite = new Graphite(host, Integer.parseInt(port));
      mReporter =
          GraphiteReporter.forRegistry(registry).convertDurationsTo(TimeUnit.MILLISECONDS)
              .convertRatesTo(TimeUnit.SECONDS).prefixedWith(prefix).build(graphite);
      MetricsSystem.checkMinimalPollingPeriod(getPollUnit(), getPollPeriod());
    }
  
    @Override
    public void start() {
      mReporter.start(getPollPeriod(), getPollUnit());
    }
  
    @Override
    public void stop() {
      mReporter.stop();
    }
  
    @Override
    public void report() {
      mReporter.report();
    }
  
    /**
     * Gets the polling period.
     *
     * @return the polling period set by properties. If it is not set, a default value 10 is
     *         returned.
     */
    private int getPollPeriod() {
      String period = mProperties.getProperty(GRAPHITE_KEY_PERIOD);
      return period != null ? Integer.parseInt(period) : GRAPHITE_DEFAULT_PERIOD;
    }
  
    /**
     * Gets the polling time unit.
     *
     * @return the polling time unit set by properties, If it is not set, a default value SECONDS is
     *         returned.
     */
    private TimeUnit getPollUnit() {
      String unit = mProperties.getProperty(GRAPHITE_KEY_UNIT);
      if (unit == null) {
        unit = GRAPHITE_DEFAULT_UNIT;
      }
      return TimeUnit.valueOf(unit.toUpperCase());
    }
  }
  