/**
    *
    * 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.hadoop.hbase.coprocessor;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.metrics.MetricRegistries;
  import org.apache.hadoop.hbase.metrics.MetricRegistry;
  import org.apache.hadoop.hbase.metrics.MetricRegistryInfo;
  
  import com.google.common.annotations.VisibleForTesting;
  
  /**
   * Utility class for tracking metrics for various types of coprocessors. Each coprocessor instance
   * creates its own MetricRegistry which is exported as an individual MetricSource. MetricRegistries
   * are ref counted using the hbase-metric module interfaces.
   */
  @InterfaceAudience.Private
  public class MetricsCoprocessor {
  
    // Master coprocessor metrics
    private static final String MASTER_COPROC_METRICS_NAME = "Coprocessor.Master";
    private static final String MASTER_COPROC_METRICS_CONTEXT = "master";
    private static final String MASTER_COPROC_METRICS_DESCRIPTION
        = "Metrics about HBase MasterObservers";
    private static final String MASTER_COPROC_METRICS_JMX_CONTEXT
        = "Master,sub=" + MASTER_COPROC_METRICS_NAME;
  
    // RegionServer coprocessor metrics
    private static final String RS_COPROC_METRICS_NAME = "Coprocessor.RegionServer";
    private static final String RS_COPROC_METRICS_CONTEXT = "regionserver";
    private static final String RS_COPROC_METRICS_DESCRIPTION
        = "Metrics about HBase RegionServerObservers";
    private static final String RS_COPROC_METRICS_JMX_CONTEXT = "RegionServer,sub="
        + RS_COPROC_METRICS_NAME;
  
    // Region coprocessor metrics
    private static final String REGION_COPROC_METRICS_NAME = "Coprocessor.Region";
    private static final String REGION_COPROC_METRICS_CONTEXT = "regionserver";
    private static final String REGION_COPROC_METRICS_DESCRIPTION
        = "Metrics about HBase RegionObservers";
    private static final String REGION_COPROC_METRICS_JMX_CONTEXT
        = "RegionServer,sub=" + REGION_COPROC_METRICS_NAME;
  
    // WAL coprocessor metrics
    private static final String WAL_COPROC_METRICS_NAME = "Coprocessor.WAL";
    private static final String WAL_COPROC_METRICS_CONTEXT = "regionserver";
    private static final String WAL_COPROC_METRICS_DESCRIPTION
        = "Metrics about HBase WALObservers";
    private static final String WAL_COPROC_METRICS_JMX_CONTEXT
        = "RegionServer,sub=" + WAL_COPROC_METRICS_NAME;
  
    private static String suffix(String metricName, String cpName) {
      return new StringBuilder(metricName)
          .append(".")
          .append("CP_")
          .append(cpName)
          .toString();
    }
  
    @VisibleForTesting
    static MetricRegistryInfo createRegistryInfoForMasterCoprocessor(String clazz) {
      return new MetricRegistryInfo(
          suffix(MASTER_COPROC_METRICS_NAME, clazz),
          MASTER_COPROC_METRICS_DESCRIPTION,
          suffix(MASTER_COPROC_METRICS_JMX_CONTEXT, clazz),
          MASTER_COPROC_METRICS_CONTEXT, false);
    }
  
    public static MetricRegistry createRegistryForMasterCoprocessor(String clazz) {
      return MetricRegistries.global().create(createRegistryInfoForMasterCoprocessor(clazz));
    }
  
    @VisibleForTesting
    static MetricRegistryInfo createRegistryInfoForRSCoprocessor(String clazz) {
      return new MetricRegistryInfo(
          suffix(RS_COPROC_METRICS_NAME, clazz),
          RS_COPROC_METRICS_DESCRIPTION,
          suffix(RS_COPROC_METRICS_JMX_CONTEXT, clazz),
          RS_COPROC_METRICS_CONTEXT, false);
    }
  
   public static MetricRegistry createRegistryForRSCoprocessor(String clazz) {
     return MetricRegistries.global().create(createRegistryInfoForRSCoprocessor(clazz));
   }
 
   @VisibleForTesting
   public static MetricRegistryInfo createRegistryInfoForRegionCoprocessor(String clazz) {
     return new MetricRegistryInfo(
         suffix(REGION_COPROC_METRICS_NAME, clazz),
         REGION_COPROC_METRICS_DESCRIPTION,
         suffix(REGION_COPROC_METRICS_JMX_CONTEXT, clazz),
         REGION_COPROC_METRICS_CONTEXT, false);
   }
 
   public static MetricRegistry createRegistryForRegionCoprocessor(String clazz) {
     return MetricRegistries.global().create(createRegistryInfoForRegionCoprocessor(clazz));
   }
 
   @VisibleForTesting
   public static MetricRegistryInfo createRegistryInfoForWALCoprocessor(String clazz) {
     return new MetricRegistryInfo(
         suffix(WAL_COPROC_METRICS_NAME, clazz),
         WAL_COPROC_METRICS_DESCRIPTION,
         suffix(WAL_COPROC_METRICS_JMX_CONTEXT, clazz),
         WAL_COPROC_METRICS_CONTEXT, false);
   }
 
   public static MetricRegistry createRegistryForWALCoprocessor(String clazz) {
     return MetricRegistries.global().create(createRegistryInfoForWALCoprocessor(clazz));
   }
 
   public static void removeRegistry(MetricRegistry registry) {
     if (registry == null) {
       return;
     }
     MetricRegistries.global().remove(registry.getMetricRegistryInfo());
   }
 }