/*

  * 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.giraph.metrics;

 import org.apache.giraph.conf.GiraphConfiguration;

 import com.yammer.metrics.core.Counter;

 import com.yammer.metrics.core.Gauge;

 import com.yammer.metrics.core.Histogram;

 import com.yammer.metrics.core.Meter;

 import com.yammer.metrics.core.Metric;

 import com.yammer.metrics.core.MetricName;

 import com.yammer.metrics.core.MetricPredicate;

 import com.yammer.metrics.core.MetricsRegistry;

 import com.yammer.metrics.core.Timer;

 import com.yammer.metrics.reporting.ConsoleReporter;

 import com.yammer.metrics.reporting.JmxReporter;

 import java.io.PrintStream;

 import java.util.Map;

 import java.util.concurrent.TimeUnit;

 /**

  * A holder for MetricsRegistry together with a JmxReporter.

  */

 public class GiraphMetricsRegistry {

   /** String name of group to use for metrics created */

   private String groupName;

   /** String type to use for metrics created */

   private String type;

   /** Internal Yammer registry used */

   private final MetricsRegistry registry;

   /** JmxReporter that send metrics to JMX */

   private final JmxReporter jmxReporter;

   /**

    * Constructor

    * @param registry {@link MetricsRegistry} to use

    * @param reporter {@link JmxReporter} to use

    * @param groupName String grouping for metrics

    * @param type String type name for metrics

    */

   protected GiraphMetricsRegistry(MetricsRegistry registry,

       JmxReporter reporter, String groupName, String type) {

     this.registry = registry;

     this.jmxReporter = reporter;

     this.groupName = groupName;

     this.type = type;

     if (jmxReporter != null) {

       jmxReporter.start();

     }

   }

   /**

    * Create no-op empty registry that makes no-op metrics.

    * @return fake registry that makes no-op metrics

    */

   public static GiraphMetricsRegistry createFake() {

     return new GiraphMetricsRegistry(new NoOpMetricsRegistry(), null, "", "");

   }

   /**

    * Create registry with group to use for metrics.

    *

    * @param groupName String group to use for metrics.

    * @param type String type to use for metrics.

    * @return new metrics registry

    */

   public static GiraphMetricsRegistry createWithOptional(String groupName,

     String type) {

     MetricsRegistry registry = new MetricsRegistry();

     return new GiraphMetricsRegistry(registry, new JmxReporter(registry),

         groupName, type);

   }

   /**

    * Create registry with Hadoop Configuration and group to use for metrics.

    * Checks the configuration object for whether the optional metrics are

    * enabled, and optionally creates those.

    *

    * @param conf Hadoop Configuration to use.

    * @param groupName String group to use for metrics.

    * @param type String type to use for metrics.

    * @return new metrics registry

    */

   public static GiraphMetricsRegistry create(GiraphConfiguration conf,

     String groupName, String type) {

     if (conf.metricsEnabled()) {

       return createWithOptional(groupName, type);

     } else {

       return createFake();

     }

   }

   /**

    * Get map of all metrics.

    *

    * @return Map of all metrics held.

    */

   public Map<MetricName, Metric> getAll() {

     return registry.allMetrics();

   }

   /**

    * Get group name used for metrics.

    *

    * @return String group name.

    */

   public String getGroupName() {

     return groupName;

   }

   /**

    * Set group name used by this MetricsRegistry. Used for incrementing

    * superstep number to create a new hierarchy of metrics per superstep.

    *

    * @param groupName String group name to use.

    */

   protected void setGroupName(String groupName) {

     this.groupName = groupName;

   }

   /**

    * Get type used for new metrics created

    *

    * @return String type to use for metrics

    */

   public String getType() {

     return type;

   }

   /**

    * Set type to use for new metrics

    *

    * @param type String type to use

    */

   public void setType(String type) {

     this.type = type;

   }

   /**

    * Dump all the metrics to the PrintStream provided.

    *

    * @param out PrintStream to write metrics to.

    */

   public void printToStream(PrintStream out) {

     out.println("");

     new ConsoleReporter(registry, out, MetricPredicate.ALL).run();

   }

   /**

    * Get internal MetricsRegistry used.

    *

    * @return MetricsRegistry being used.

    */

   protected MetricsRegistry getInternalRegistry() {

     return registry;

   }

   /**

    * Creates a new {@link com.yammer.metrics.core.Counter} and registers it

    * under the given group and name.

    *

    * @param name the name of the metric

    * @return a new {@link com.yammer.metrics.core.Counter}

    */

   public Counter getCounter(String name) {

     return registry.newCounter(makeMetricName(name));

   }

   /**

    * Given a new {@link com.yammer.metrics.core.Gauge}, registers it under the

    * given group and name.

    *

    * @param name   the name of the metric

    * @param metric the metric

    * @param <T>    the type of the value returned by the metric

    * @return {@code metric}

    */

   public <T> Gauge<T> getGauge(String name, Gauge<T> metric) {

     return registry.newGauge(makeMetricName(name), metric);

   }

   /**

    * Creates a new biased {@link Histogram} and registers it under the given

    * group and name

    *

    * @param name name of metric

    * @return new {@link Histogram}

    */

   public Histogram getBiasedHistogram(String name) {

     return getHistogram(name, true);

   }

   /**

    * Creates a new uniform {@link Histogram} and registers it under the given

    * group and name

    *

    * @param name name of metric

    * @return new {@link Histogram}

    */

   public Histogram getUniformHistogram(String name) {

     return getHistogram(name, false);

   }

   /**

    * Creates a new {@link Histogram} and registers it under the given group

    * and name.

    *

    * @param name   the name of the metric

    * @param biased whether or not the histogram should be biased

    * @return a new {@link Histogram}

    */

   private Histogram getHistogram(String name, boolean biased) {

     return registry.newHistogram(makeMetricName(name), biased);

   }

   /**

    * Creates a new {@link com.yammer.metrics.core.Meter} and registers it under

    * the given group and name.

    *

    * @param meterDesc description of meter

    * @return new {@link com.yammer.metrics.core.Meter}

    */

   public Meter getMeter(MeterDesc meterDesc) {

     return getMeter(meterDesc.getName(), meterDesc.getType(),

         meterDesc.getTimeUnit());

   }

   /**

    * Creates a new {@link com.yammer.metrics.core.Meter} and registers it under

    * the given group and name.

    *

    * @param name      the name of the metric

    * @param eventType the plural name of the type of events the meter is

    *                  measuring (e.g., {@code "requests"})

    * @param timeUnit  the rate unit of the new meter

    * @return a new {@link com.yammer.metrics.core.Meter}

    */

   public Meter getMeter(String name, String eventType, TimeUnit timeUnit) {

     return registry.newMeter(makeMetricName(name), eventType, timeUnit);

   }

   /**

    * Creates a new {@link Timer} and registers it under the given

    * group and name.

    *

    * @param name         the name of the metric

    * @param durationUnit the duration scale unit of the new timer

    * @param rateUnit     the rate scale unit of the new timer

    * @return a new {@link Timer}

    */

   public Timer getTimer(String name, TimeUnit durationUnit, TimeUnit rateUnit) {

     return registry.newTimer(makeMetricName(name), durationUnit, rateUnit);

   }

   /**

    * Get a Gauge that is already present in the MetricsRegistry

    *

    * @param name String name of Gauge

    * @param <T> type of gauge

    * @return Gauge, from MetricsRegistry

    */

   public <T> Gauge<T> getExistingGauge(String name) {

     Metric metric = registry.allMetrics().get(makeMetricName(name));

     return metric instanceof Gauge ? (Gauge<T>) metric : null;

   }

   /**

    * Create a MetricName using the job ID, group, and name.

    *

    * @param name String name given to metric

    * @return MetricName for use with MetricsRegistry

    */

   protected MetricName makeMetricName(String name) {

     return new MetricName(groupName, type, name);

   }

   /**

    * Nothing will be captured after this is called.

    */

   public void shutdown() {

     registry.shutdown();

   }

 }