/**
    *
    * 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.wal;
  
  import java.io.IOException;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.wal.WALKey;
  import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
  import org.apache.hadoop.util.StringUtils;
  
  /**
   * Class used to push numbers about the WAL into the metrics subsystem.  This will take a
   * single function call and turn it into multiple manipulations of the hadoop metrics system.
   */
  @InterfaceAudience.Private
  public class MetricsWAL extends WALActionsListener.Base {
    private static final Log LOG = LogFactory.getLog(MetricsWAL.class);
  
    private final MetricsWALSource source;
  
    public MetricsWAL() {
      this(CompatibilitySingletonFactory.getInstance(MetricsWALSource.class));
    }
  
    MetricsWAL(MetricsWALSource s) {
      this.source = s;
    }
  
    @Override
    public void postSync(final long timeInNanos, final int handlerSyncs) {
      source.incrementSyncTime(timeInNanos/1000000L);
    }
  
    @Override
    public void postAppend(final long size, final long time, final WALKey logkey,
        final WALEdit logEdit) throws IOException {
      TableName tableName = logkey.getTablename();
      source.incrementAppendCount(tableName);
      source.incrementAppendTime(time);
      source.incrementAppendSize(tableName, size);
      source.incrementWrittenBytes(size);
  
      if (time > 1000) {
        source.incrementSlowAppendCount();
        LOG.warn(String.format("%s took %d ms appending an edit to wal; len~=%s",
            Thread.currentThread().getName(),
            time,
            StringUtils.humanReadableInt(size)));
      }
    }
  
    @Override
    public void logRollRequested(WALActionsListener.RollRequestReason reason) {
      source.incrementLogRollRequested();
      switch (reason) {
        case ERROR:
          source.incrementErrorLogRoll();
          break;
        case LOW_REPLICATION:
          source.incrementLowReplicationLogRoll();
          break;
        case SIZE:
          source.incrementSizeLogRoll();
          break;
        case SLOW_SYNC:
          source.incrementSlowSyncLogRoll();
          break;
        default:
          break;
      }
    }
  
    @Override
    public void postLogRoll(Path oldPath, Path newPath) {
      // oldPath can be null if this is the first time we created a wal
      // Also newPath can be equal to oldPath if AbstractFSWAL#replaceWriter fails
      if (newPath != oldPath) {
       source.incrementSuccessfulLogRolls();
     }
   }
 }