content: /*
   * 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 com.alibaba.metrics.jvm;
  
  import com.alibaba.metrics.Metric;
  import com.alibaba.metrics.MetricName;
  import com.alibaba.metrics.MetricRegistry;
  import com.alibaba.metrics.MetricSet;
  import com.alibaba.metrics.PersistentGauge;
  import com.alibaba.metrics.RatioGauge;
  
  import java.lang.management.ManagementFactory;
  import java.lang.management.MemoryMXBean;
  import java.lang.management.MemoryPoolMXBean;
  import java.lang.management.MemoryUsage;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.regex.Pattern;
  
  /**
   * A set of gauges for JVM memory usage, including stats on heap vs. non-heap memory, plus
   * GC-specific memory pools.
   * +----------------------------------------------+
   * +////////////////           |                  +
   * +////////////////           |                  +
   * +----------------------------------------------+
   *
   * |--------|
   *   init
   * |---------------|
   *        used
   * |---------------------------|
   *             committed
   * |----------------------------------------------|
   *                         max
   */
  public class MemoryUsageGaugeSet implements MetricSet {
      private static final Pattern WHITESPACE = Pattern.compile("[\\s]+");
  
      private final MemoryMXBean mxBean;
      private final List<MemoryPoolMXBean> memoryPools;
  
      public MemoryUsageGaugeSet() {
          this(ManagementFactory.getMemoryMXBean(),
               ManagementFactory.getMemoryPoolMXBeans());
      }
  
      public MemoryUsageGaugeSet(MemoryMXBean mxBean,
                                 Collection<MemoryPoolMXBean> memoryPools) {
          this.mxBean = mxBean;
          this.memoryPools = new ArrayList<MemoryPoolMXBean>(memoryPools);
      }
  
      @Override
      public Map<MetricName, Metric> getMetrics() {
          final Map<MetricName, Metric> gauges = new HashMap<MetricName, Metric>();
  
          gauges.put(MetricName.build("total.init"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getInit() +
                          mxBean.getNonHeapMemoryUsage().getInit();
              }
          });
  
          gauges.put(MetricName.build("total.used"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getUsed() +
                          mxBean.getNonHeapMemoryUsage().getUsed();
              }
          });
  
          gauges.put(MetricName.build("total.max"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getMax() +
                          mxBean.getNonHeapMemoryUsage().getMax();
              }
          });
  
          gauges.put(MetricName.build("total.committed"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getCommitted() +
                          mxBean.getNonHeapMemoryUsage().getCommitted();
              }
          });
  
  
          gauges.put(MetricName.build("heap.init"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getInit();
              }
          });
  
          gauges.put(MetricName.build("heap.used"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getUsed();
              }
          });
  
          gauges.put(MetricName.build("heap.max"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getMax();
              }
          });
  
          gauges.put(MetricName.build("heap.committed"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getHeapMemoryUsage().getCommitted();
              }
          });
  
          gauges.put(MetricName.build("heap.usage"), new RatioGauge() {
              @Override
              protected Ratio getRatio() {
                  final MemoryUsage usage = mxBean.getHeapMemoryUsage();
                  return Ratio.of(usage.getUsed(), usage.getMax() == -1 ? usage.getCommitted() : usage.getMax());
              }
          });
  
          gauges.put(MetricName.build("non_heap.init"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getNonHeapMemoryUsage().getInit();
              }
          });
  
          gauges.put(MetricName.build("non_heap.used"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getNonHeapMemoryUsage().getUsed();
              }
          });
  
          gauges.put(MetricName.build("non_heap.max"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getNonHeapMemoryUsage().getMax();
              }
          });
  
          gauges.put(MetricName.build("non_heap.committed"), new PersistentGauge<Long>() {
              @Override
              public Long getValue() {
                  return mxBean.getNonHeapMemoryUsage().getCommitted();
              }
          });
  
          gauges.put(MetricName.build("non_heap.usage"), new RatioGauge() {
              @Override
              protected Ratio getRatio() {
                  final MemoryUsage usage = mxBean.getNonHeapMemoryUsage();
                  return Ratio.of(usage.getUsed(), usage.getMax() == -1 ? usage.getCommitted() : usage.getMax());
              }
          });
  
          for (final MemoryPoolMXBean pool : memoryPools) {
              final MetricName poolName = MetricRegistry.name("pools",
                      WHITESPACE.matcher(pool.getName()).replaceAll("_").toLowerCase());
  
              gauges.put(poolName.resolve("usage"),
                      new RatioGauge() {
                             @Override
                             protected Ratio getRatio() {
                                 MemoryUsage usage = pool.getUsage();
                                 return Ratio.of(usage.getUsed(),
                                         usage.getMax() == -1 ? usage.getCommitted() : usage.getMax());
                             }
                      });
  
              gauges.put(poolName.resolve("max"),new PersistentGauge<Long>() {
                  @Override
                  public Long getValue() {
                      return pool.getUsage().getMax();
                  }
              });
  
              gauges.put(poolName.resolve("used"),new PersistentGauge<Long>() {
                  @Override
                  public Long getValue() {
                      return pool.getUsage().getUsed();
                  }
              });
  
              gauges.put(poolName.resolve("committed"),new PersistentGauge<Long>() {
                  @Override
                  public Long getValue() {
                      return pool.getUsage().getCommitted();
                  }
              });
  
              // Only register GC usage metrics if the memory pool supports usage statistics.
              if (pool.getCollectionUsage() != null) {
                  gauges.put(poolName.resolve("used_after_gc"),new PersistentGauge<Long>() {
                      @Override
                      public Long getValue() {
                          return pool.getCollectionUsage().getUsed();
                      }
                  });
              }
  
              gauges.put(poolName.resolve("init"),new PersistentGauge<Long>() {
                  @Override
                  public Long getValue() {
                      return pool.getUsage().getInit();
                  }
              });
          }
  
          return Collections.unmodifiableMap(gauges);
      }
  
      @Override
      public long lastUpdateTime() {
          return System.currentTimeMillis();
      }
  }
  