/*
    * 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.regionserver;
  
  import java.util.HashMap;
  
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.metrics.BaseSourceImpl;
  import org.apache.hadoop.metrics2.MetricHistogram;
  import org.apache.hadoop.metrics2.lib.DynamicMetricsRegistry;
  
  import com.google.common.annotations.VisibleForTesting;
  
  /**
   * Implementation of {@link MetricsTableLatencies} to track latencies for one table in a
   * RegionServer.
   */
  @InterfaceAudience.Private
  public class MetricsTableLatenciesImpl extends BaseSourceImpl implements MetricsTableLatencies {
  
    private final HashMap<TableName,TableHistograms> histogramsByTable = new HashMap<>();
  
    @VisibleForTesting
    public static class TableHistograms {
      final MetricHistogram getTimeHisto;
      final MetricHistogram incrementTimeHisto;
      final MetricHistogram appendTimeHisto;
      final MetricHistogram putTimeHisto;
      final MetricHistogram putBatchTimeHisto;
      final MetricHistogram deleteTimeHisto;
      final MetricHistogram deleteBatchTimeHisto;
      final MetricHistogram scanTimeHisto;
      final MetricHistogram scanSizeHisto;
  
      TableHistograms(DynamicMetricsRegistry registry, TableName tn) {
        getTimeHisto = registry.newTimeHistogram(qualifyMetricsName(tn, GET_TIME));
        incrementTimeHisto = registry.newTimeHistogram(
            qualifyMetricsName(tn, INCREMENT_TIME));
        appendTimeHisto = registry.newTimeHistogram(qualifyMetricsName(tn, APPEND_TIME));
        putTimeHisto = registry.newTimeHistogram(qualifyMetricsName(tn, PUT_TIME));
        putBatchTimeHisto = registry.newTimeHistogram(qualifyMetricsName(tn, PUT_BATCH_TIME));
        deleteTimeHisto = registry.newTimeHistogram(qualifyMetricsName(tn, DELETE_TIME));
        deleteBatchTimeHisto = registry.newTimeHistogram(
            qualifyMetricsName(tn, DELETE_BATCH_TIME));
        scanTimeHisto = registry.newTimeHistogram(qualifyMetricsName(tn, SCAN_TIME));
        scanSizeHisto = registry.newSizeHistogram(qualifyMetricsName(tn, SCAN_SIZE));
      }
  
      public void updatePut(long time) {
        putTimeHisto.add(time);
      }
  
      public void updatePutBatch(long time) {
        putBatchTimeHisto.add(time);
      }
  
      public void updateDelete(long t) {
        deleteTimeHisto.add(t);
      }
  
      public void updateDeleteBatch(long t) {
        deleteBatchTimeHisto.add(t);
      }
  
      public void updateGet(long t) {
        getTimeHisto.add(t);
      }
  
      public void updateIncrement(long t) {
        incrementTimeHisto.add(t);
      }
  
      public void updateAppend(long t) {
        appendTimeHisto.add(t);
      }
  
      public void updateScanSize(long scanSize) {
        scanSizeHisto.add(scanSize);
      }
  
      public void updateScanTime(long t) {
        scanTimeHisto.add(t);
      }
    }
 
   @VisibleForTesting
   public static String qualifyMetricsName(TableName tableName, String metric) {
     StringBuilder sb = new StringBuilder();
     sb.append("Namespace_").append(tableName.getNamespaceAsString());
     sb.append("_table_").append(tableName.getQualifierAsString());
     sb.append("_metric_").append(metric);
     return sb.toString();
   }
 
   @VisibleForTesting
   public TableHistograms getOrCreateTableHistogram(String tableName) {
     // TODO Java8's ConcurrentHashMap#computeIfAbsent would be stellar instead
     final TableName tn = TableName.valueOf(tableName);
     TableHistograms latency = histogramsByTable.get(tn);
     if (latency == null) {
       latency = new TableHistograms(getMetricsRegistry(), tn);
       histogramsByTable.put(tn, latency);
     }
     return latency;
   }
 
   public MetricsTableLatenciesImpl() {
     this(METRICS_NAME, METRICS_DESCRIPTION, METRICS_CONTEXT, METRICS_JMX_CONTEXT);
   }
 
   public MetricsTableLatenciesImpl(String metricsName, String metricsDescription,
       String metricsContext, String metricsJmxContext) {
     super(metricsName, metricsDescription, metricsContext, metricsJmxContext);
   }
 
   @Override
   public void updatePut(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updatePut(t);
   }
 
   @Override
   public void updatePutBatch(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updatePutBatch(t);
   }
 
   @Override
   public void updateDelete(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updateDelete(t);
   }
 
   @Override
   public void updateDeleteBatch(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updateDeleteBatch(t);
   }
 
   @Override
   public void updateGet(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updateGet(t);
   }
 
   @Override
   public void updateIncrement(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updateIncrement(t);
   }
 
   @Override
   public void updateAppend(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updateAppend(t);
   }
 
   @Override
   public void updateScanSize(String tableName, long scanSize) {
     getOrCreateTableHistogram(tableName).updateScanSize(scanSize);
   }
 
   @Override
   public void updateScanTime(String tableName, long t) {
     getOrCreateTableHistogram(tableName).updateScanTime(t);
   }
 }