BasicCompositeMonitor.java

/**
 * Copyright 2013 Netflix, Inc.
 * <p/>
 * Licensed 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
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * 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.netflix.servo.monitor;

import com.netflix.servo.util.UnmodifiableList;

import java.util.List;

/**
 * Simple composite monitor type with a static list of sub-monitors. The value for the composite
 * is the number of sub-monitors.
 */
public final class BasicCompositeMonitor extends AbstractMonitor<Integer>
    implements CompositeMonitor<Integer> {
  private final List<Monitor<?>> monitors;

  /**
   * Create a new composite.
   *
   * @param config   configuration for the composite. It is recommended that the configuration
   *                 shares common tags with the sub-monitors, but it is not enforced.
   * @param monitors list of sub-monitors
   */
  public BasicCompositeMonitor(MonitorConfig config, List<Monitor<?>> monitors) {
    super(config);
    this.monitors = UnmodifiableList.copyOf(monitors);
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public Integer getValue(int pollerIdx) {
    return monitors.size();
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public List<Monitor<?>> getMonitors() {
    return monitors;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public boolean equals(Object obj) {
    if (obj == null || !(obj instanceof BasicCompositeMonitor)) {
      return false;
    }
    BasicCompositeMonitor m = (BasicCompositeMonitor) obj;
    return config.equals(m.getConfig()) && monitors.equals(m.getMonitors());
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public int hashCode() {
    int result = config.hashCode();
    result = 31 * result + monitors.hashCode();
    return result;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public String toString() {
    return "BasicCompositeMonitor{config=" + config + ", monitors=" + monitors + '}';
  }
}