Line data    Source code

       1             : // Copyright (C) 2015 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.metrics.dropwizard;
      16             : 
      17             : import com.codahale.metrics.Gauge;
      18             : import com.codahale.metrics.Metric;
      19             : import com.codahale.metrics.MetricRegistry;
      20             : import com.google.common.collect.ImmutableList;
      21             : import com.google.common.collect.Maps;
      22             : import com.google.gerrit.metrics.Description;
      23             : import com.google.gerrit.metrics.Field;
      24             : import java.util.Iterator;
      25             : import java.util.Map;
      26             : import java.util.concurrent.ConcurrentHashMap;
      27             : 
      28             : /** Abstract callback metric broken down into buckets. */
      29             : abstract class BucketedCallback<V> implements BucketedMetric {
      30             :   private final DropWizardMetricMaker metrics;
      31             :   private final MetricRegistry registry;
      32             :   private final String name;
      33             :   private final Description.FieldOrdering ordering;
      34             :   protected final Field<?>[] fields;
      35             :   private final V zero;
      36             :   private final Map<Object, ValueGauge> cells;
      37             :   protected volatile Runnable trigger;
      38          16 :   private final Object lock = new Object();
      39             : 
      40             :   BucketedCallback(
      41             :       DropWizardMetricMaker metrics,
      42             :       MetricRegistry registry,
      43             :       String name,
      44             :       Class<V> valueType,
      45             :       Description desc,
      46          16 :       Field<?>... fields) {
      47          16 :     this.metrics = metrics;
      48          16 :     this.registry = registry;
      49          16 :     this.name = name;
      50          16 :     this.ordering = desc.getFieldOrdering();
      51          16 :     this.fields = fields;
      52          16 :     this.zero = CallbackMetricImpl0.zeroFor(valueType);
      53          16 :     this.cells = new ConcurrentHashMap<>();
      54          16 :   }
      55             : 
      56             :   void doRemove() {
      57           0 :     for (Object key : cells.keySet()) {
      58           0 :       registry.remove(submetric(key));
      59           0 :     }
      60           0 :     metrics.remove(name);
      61           0 :   }
      62             : 
      63             :   void doBeginSet() {
      64          16 :     for (ValueGauge g : cells.values()) {
      65           0 :       g.set = false;
      66           0 :     }
      67          16 :   }
      68             : 
      69             :   void doPrune() {
      70          15 :     Iterator<Map.Entry<Object, ValueGauge>> it = cells.entrySet().iterator();
      71          15 :     while (it.hasNext()) {
      72          15 :       Map.Entry<Object, ValueGauge> e = it.next();
      73          15 :       if (!e.getValue().set) {
      74           0 :         it.remove();
      75           0 :         registry.remove(submetric(e.getKey()));
      76             :       }
      77          15 :     }
      78          15 :   }
      79             : 
      80             :   void doEndSet() {
      81          16 :     for (ValueGauge g : cells.values()) {
      82          16 :       if (!g.set) {
      83          16 :         g.value = zero;
      84             :       }
      85          16 :     }
      86          16 :   }
      87             : 
      88             :   ValueGauge getOrCreate(Object f1, Object f2) {
      89           0 :     return getOrCreate(ImmutableList.of(f1, f2));
      90             :   }
      91             : 
      92             :   ValueGauge getOrCreate(Object f1, Object f2, Object f3) {
      93           0 :     return getOrCreate(ImmutableList.of(f1, f2, f3));
      94             :   }
      95             : 
      96             :   ValueGauge getOrCreate(Object key) {
      97          16 :     ValueGauge c = cells.get(key);
      98          16 :     if (c != null) {
      99           0 :       return c;
     100             :     }
     101             : 
     102          16 :     synchronized (lock) {
     103          16 :       c = cells.get(key);
     104          16 :       if (c == null) {
     105          16 :         c = new ValueGauge();
     106          16 :         registry.register(submetric(key), c);
     107          16 :         cells.put(key, c);
     108             :       }
     109          16 :       return c;
     110             :     }
     111             :   }
     112             : 
     113             :   private String submetric(Object key) {
     114          16 :     return DropWizardMetricMaker.name(ordering, name, name(key));
     115             :   }
     116             : 
     117             :   abstract String name(Object key);
     118             : 
     119             :   @Override
     120             :   public Metric getTotal() {
     121           0 :     return null;
     122             :   }
     123             : 
     124             :   @Override
     125             :   public Field<?>[] getFields() {
     126           0 :     return fields;
     127             :   }
     128             : 
     129             :   @Override
     130             :   public Map<Object, Metric> getCells() {
     131           0 :     return Maps.transformValues(cells, in -> in);
     132             :   }
     133             : 
     134          16 :   final class ValueGauge implements Gauge<V> {
     135          16 :     volatile V value = zero;
     136             :     boolean set;
     137             : 
     138             :     @Override
     139             :     public V getValue() {
     140           0 :       Runnable t = trigger;
     141           0 :       if (t != null) {
     142           0 :         t.run();
     143             :       }
     144           0 :       return value;
     145             :     }
     146             :   }
     147             : }