/*
    * 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 java.io.PrintStream;
  
  import org.apache.giraph.bsp.BspService;
  import org.apache.giraph.conf.GiraphConfiguration;
  
  import com.yammer.metrics.core.Histogram;
  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.reporting.ConsoleReporter;
  import com.yammer.metrics.reporting.JmxReporter;
  
  /**
   * Wrapper around MetricsRegistry for per-superstep metrics.
   */
  public class SuperstepMetricsRegistry extends GiraphMetricsRegistry {
    /** Number of superstep to use for group of metrics created */
    private long superstep = BspService.INPUT_SUPERSTEP;
  
    /**
     * Constructor
     * @param registry {@link com.yammer.metrics.core.MetricsRegistry} to use
     * @param reporter {@link com.yammer.metrics.reporting.JmxReporter} to use
     * @param groupName String grouping for metrics
     * @param type String type name for metrics
     */
    protected SuperstepMetricsRegistry(MetricsRegistry registry,
        JmxReporter reporter, String groupName, String type) {
      super(registry, reporter, groupName, type);
    }
  
    /**
     * Create with Hadoop Configuration and superstep number.
     *
     * @param conf Hadoop Configuration to use.
     * @param superstep number of superstep to use as group for metrics.
     * @return new metrics registry
     */
    public static SuperstepMetricsRegistry create(GiraphConfiguration conf,
        long superstep) {
      if (conf.metricsEnabled()) {
        MetricsRegistry registry = new MetricsRegistry();
        SuperstepMetricsRegistry superstepMetrics = new SuperstepMetricsRegistry(
            registry, new JmxReporter(registry),
            "giraph.superstep", String.valueOf(superstep));
        superstepMetrics.superstep = superstep;
        return superstepMetrics;
      } else {
        return createFake();
      }
    }
  
    /**
     * Create an empty registry
     * @return fake metrics registry that returns no op metrics
     */
    public static SuperstepMetricsRegistry createFake() {
      return new SuperstepMetricsRegistry(new NoOpMetricsRegistry(), null,
          "", "");
    }
  
    /**
     * Get superstep stored here
     * @return long superstep
     */
    public long getSuperstep() {
      return superstep;
    }
  
    /**
     * Set superstep number used. Internally sets the group for metrics created.
     *
     * @param superstep long number of superstep to use.
     */
    public void setSuperstep(long superstep) {
      super.setType(String.valueOf(superstep));
      this.superstep = superstep;
    }
 
   /**
    * Print human readable summary of superstep metrics.
    *
    * @param out PrintStream to write to.
    */
   public void printSummary(PrintStream out) {
     new WorkerSuperstepMetrics().readFromRegistry().print(superstep, out);
     out.println("");
     MetricPredicate superstepFilter = new MetricPredicate() {
       @Override
       public boolean matches(MetricName name, Metric metric) {
         return name.getType().equals(getType());
       }
     };
     new ConsoleReporter(getInternalRegistry(), out, superstepFilter) {
       @Override
       public void processHistogram(MetricName name, Histogram histogram,
           PrintStream stream) {
         stream.printf("               sum = %,2.2f%n", histogram.sum());
         super.processHistogram(name, histogram, stream);
         stream.printf("             count = %d%n", histogram.count());
       }
     } .run();
   }
 }