/**
    * 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.replication.regionserver;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
  import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
  
  /**
   * This class is for maintaining the various replication statistics for a source and publishing them
   * through the metrics interfaces.
   */
  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION)
  public class MetricsSource {
  
    private static final Log LOG = LogFactory.getLog(MetricsSource.class);
  
    // tracks last shipped timestamp for each wal group
    private Map<String, Long> lastTimeStamps = new HashMap<String, Long>();
    private int lastQueueSize = 0;
    private String id;
  
    private final MetricsReplicationSourceSource singleSourceSource;
    private final MetricsReplicationSourceSource globalSourceSource;
  
    /**
     * Constructor used to register the metrics
     *
     * @param id Name of the source this class is monitoring
     */
    public MetricsSource(String id) {
      this.id = id;
      singleSourceSource =
          CompatibilitySingletonFactory.getInstance(MetricsReplicationSourceFactory.class)
              .getSource(id);
      globalSourceSource = CompatibilitySingletonFactory.getInstance(MetricsReplicationSourceFactory.class).getGlobalSource();
    }
  
    /**
     * Set the age of the last edit that was shipped
     * @param timestamp write time of the edit
     * @param walGroup which group we are setting
     */
    public void setAgeOfLastShippedOp(long timestamp, String walGroup) {
      long age = EnvironmentEdgeManager.currentTime() - timestamp;
      singleSourceSource.setLastShippedAge(age);
      globalSourceSource.setLastShippedAge(Math.max(age, globalSourceSource.getLastShippedAge()));
      this.lastTimeStamps.put(walGroup, timestamp);
    }
  
    /**
     * Convenience method to use the last given timestamp to refresh the age of the last edit. Used
     * when replication fails and need to keep that metric accurate.
     * @param walGroupId id of the group to update
     */
    public void refreshAgeOfLastShippedOp(String walGroupId) {
      Long lastTimestamp = this.lastTimeStamps.get(walGroupId);
      if (lastTimestamp == null) {
        this.lastTimeStamps.put(walGroupId, 0L);
        lastTimestamp = 0L;
      }
      if (lastTimestamp > 0) {
        setAgeOfLastShippedOp(lastTimestamp, walGroupId);
      }
    }
  
    /**
     * Set the size of the log queue
     *
     * @param size the size.
     */
    public void setSizeOfLogQueue(int size) {
      singleSourceSource.setSizeOfLogQueue(size);
      globalSourceSource.incrSizeOfLogQueue(size - lastQueueSize);
      lastQueueSize = size;
    }
  
   /**
    * Add on the the number of log edits read
    *
    * @param delta the number of log edits read.
    */
   private void incrLogEditsRead(long delta) {
     singleSourceSource.incrLogReadInEdits(delta);
     globalSourceSource.incrLogReadInEdits(delta);
   }
 
   /** Increment the number of log edits read by one. */
   public void incrLogEditsRead() {
     incrLogEditsRead(1);
   }
 
   /**
    * Add on the number of log edits filtered
    *
    * @param delta the number filtered.
    */
   public void incrLogEditsFiltered(long delta) {
     singleSourceSource.incrLogEditsFiltered(delta);
     globalSourceSource.incrLogEditsFiltered(delta);
   }
 
   /** The number of log edits filtered out. */
   public void incrLogEditsFiltered() {
     incrLogEditsFiltered(1);
   }
 
   /**
    * Convience method to apply changes to metrics do to shipping a batch of logs.
    *
    * @param batchSize the size of the batch that was shipped to sinks.
    */
   public void shipBatch(long batchSize, int sizeInKB) {
     singleSourceSource.incrBatchesShipped(1);
     globalSourceSource.incrBatchesShipped(1);
 
     singleSourceSource.incrOpsShipped(batchSize);
     globalSourceSource.incrOpsShipped(batchSize);
 
     singleSourceSource.incrShippedKBs(sizeInKB);
     globalSourceSource.incrShippedKBs(sizeInKB);
   }
 
   /** increase the byte number read by source from log file */
   public void incrLogReadInBytes(long readInBytes) {
     singleSourceSource.incrLogReadInBytes(readInBytes);
     globalSourceSource.incrLogReadInBytes(readInBytes);
   }
 
   /** Removes all metrics about this Source. */
   public void clear() {
     singleSourceSource.clear();
     globalSourceSource.decrSizeOfLogQueue(lastQueueSize);
     lastTimeStamps.clear();
     lastQueueSize = 0;
   }
 
   /**
    * Get AgeOfLastShippedOp
    * @return AgeOfLastShippedOp
    */
   public Long getAgeOfLastShippedOp() {
     return singleSourceSource.getLastShippedAge();
   }
 
   /**
    * Get the sizeOfLogQueue
    * @return sizeOfLogQueue
    */
   public int getSizeOfLogQueue() {
     return this.lastQueueSize;
   }
 
   /**
    * Get the timeStampsOfLastShippedOp, if there are multiple groups, return the latest one
    * @return lastTimestampForAge
    */
   public long getTimeStampOfLastShippedOp() {
     long lastTimestamp = 0L;
     for (long ts : lastTimeStamps.values()) {
       if (ts > lastTimestamp) {
         lastTimestamp = ts;
       }
     }
     return lastTimestamp;
   }
 
   /**
    * Get the slave peer ID
    * @return peerID
    */
   public String getPeerID() {
     return id;
   }
 
   public void incrUnknownFileLengthForClosedWAL() {
     singleSourceSource.incrUnknownFileLengthForClosedWAL();
     globalSourceSource.incrUnknownFileLengthForClosedWAL();
   }
 
   public void incrUncleanlyClosedWALs() {
     singleSourceSource.incrUncleanlyClosedWALs();
     globalSourceSource.incrUncleanlyClosedWALs();
   }
 
   public void incrBytesSkippedInUncleanlyClosedWALs(final long bytes) {
     singleSourceSource.incrBytesSkippedInUncleanlyClosedWALs(bytes);
     globalSourceSource.incrBytesSkippedInUncleanlyClosedWALs(bytes);
   }
 
   public void incrRestartedWALReading() {
     singleSourceSource.incrRestartedWALReading();
     globalSourceSource.incrRestartedWALReading();
   }
 
   public void incrRepeatedFileBytes(final long bytes) {
     singleSourceSource.incrRepeatedFileBytes(bytes);
     globalSourceSource.incrRepeatedFileBytes(bytes);
   }
 
   public void incrCompletedWAL() {
     singleSourceSource.incrCompletedWAL();
     globalSourceSource.incrCompletedWAL();
   }
 
   public void incrCompletedRecoveryQueue() {
     singleSourceSource.incrCompletedRecoveryQueue();
     globalSourceSource.incrCompletedRecoveryQueue();
   }
 }