/**
    *
    * 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.client;
  
  import com.google.common.annotations.VisibleForTesting;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
  
  import java.io.IOException;
  import java.io.InterruptedIOException;
  import java.util.Arrays;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.concurrent.ConcurrentLinkedQueue;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * <p>
   * Used to communicate with a single HBase table similar to {@link HTable}
   * but meant for batched, potentially asynchronous puts. Obtain an instance from
   * a {@link Connection} and call {@link #close()} afterwards.
   * </p>
   *
   * <p>
   * While this can be used accross threads, great care should be used when doing so.
   * Errors are global to the buffered mutator and the Exceptions can be thrown on any
   * thread that causes the flush for requests.
   * </p>
   *
   * @see ConnectionFactory
   * @see Connection
   * @since 1.0.0
   */
  @InterfaceAudience.Private
  @InterfaceStability.Evolving
  public class BufferedMutatorImpl implements BufferedMutator {
  
    private static final Log LOG = LogFactory.getLog(BufferedMutatorImpl.class);
    
    private final ExceptionListener listener;
  
    protected ClusterConnection connection; // non-final so can be overridden in test
    private final TableName tableName;
    private volatile Configuration conf;
    @VisibleForTesting
    final ConcurrentLinkedQueue<Mutation> writeAsyncBuffer = new ConcurrentLinkedQueue<Mutation>();
    @VisibleForTesting
    AtomicLong currentWriteBufferSize = new AtomicLong(0);
  
    private long writeBufferSize;
    private final int maxKeyValueSize;
    private boolean closed = false;
    private final ExecutorService pool;
  
    @VisibleForTesting
    protected AsyncProcess ap; // non-final so can be overridden in test
  
    BufferedMutatorImpl(ClusterConnection conn, RpcRetryingCallerFactory rpcCallerFactory,
        RpcControllerFactory rpcFactory, BufferedMutatorParams params) {
      if (conn == null || conn.isClosed()) {
        throw new IllegalArgumentException("Connection is null or closed.");
      }
  
      this.tableName = params.getTableName();
      this.connection = conn;
      this.conf = connection.getConfiguration();
      this.pool = params.getPool();
      this.listener = params.getListener();
  
      ConnectionConfiguration tableConf = new ConnectionConfiguration(conf);
      this.writeBufferSize = params.getWriteBufferSize() != BufferedMutatorParams.UNSET ?
          params.getWriteBufferSize() : tableConf.getWriteBufferSize();
      this.maxKeyValueSize = params.getMaxKeyValueSize() != BufferedMutatorParams.UNSET ?
          params.getMaxKeyValueSize() : tableConf.getMaxKeyValueSize();
  
      // puts need to track errors globally due to how the APIs currently work.
      ap = new AsyncProcess(connection, conf, pool, rpcCallerFactory, true, rpcFactory);
    }
  
   @Override
   public TableName getName() {
     return tableName;
   }
 
   @Override
   public Configuration getConfiguration() {
     return conf;
   }
 
   @Override
   public void mutate(Mutation m) throws InterruptedIOException,
       RetriesExhaustedWithDetailsException {
     mutate(Arrays.asList(m));
   }
 
   @Override
   public void mutate(List<? extends Mutation> ms) throws InterruptedIOException,
       RetriesExhaustedWithDetailsException {
 
     if (closed) {
       throw new IllegalStateException("Cannot put when the BufferedMutator is closed.");
     }
 
     long toAddSize = 0;
     for (Mutation m : ms) {
       if (m instanceof Put) {
         validatePut((Put) m);
       }
       toAddSize += m.heapSize();
     }
 
     // This behavior is highly non-intuitive... it does not protect us against
     // 94-incompatible behavior, which is a timing issue because hasError, the below code
     // and setter of hasError are not synchronized. Perhaps it should be removed.
     if (ap.hasError()) {
       currentWriteBufferSize.addAndGet(toAddSize);
       writeAsyncBuffer.addAll(ms);
       backgroundFlushCommits(true);
     } else {
       currentWriteBufferSize.addAndGet(toAddSize);
       writeAsyncBuffer.addAll(ms);
     }
 
     // Now try and queue what needs to be queued.
     while (currentWriteBufferSize.get() > writeBufferSize) {
       backgroundFlushCommits(false);
     }
   }
 
   // validate for well-formedness
   public void validatePut(final Put put) throws IllegalArgumentException {
     HTable.validatePut(put, maxKeyValueSize);
   }
 
   @Override
   public synchronized void close() throws IOException {
     try {
       if (this.closed) {
         return;
       }
       // As we can have an operation in progress even if the buffer is empty, we call
       // backgroundFlushCommits at least one time.
       backgroundFlushCommits(true);
       this.pool.shutdown();
       boolean terminated;
       int loopCnt = 0;
       do {
         // wait until the pool has terminated
         terminated = this.pool.awaitTermination(60, TimeUnit.SECONDS);
         loopCnt += 1;
         if (loopCnt >= 10) {
           LOG.warn("close() failed to terminate pool after 10 minutes. Abandoning pool.");
           break;
         }
       } while (!terminated);
 
     } catch (InterruptedException e) {
       LOG.warn("waitForTermination interrupted");
 
     } finally {
       this.closed = true;
     }
   }
 
   @Override
   public synchronized void flush() throws InterruptedIOException,
       RetriesExhaustedWithDetailsException {
     // As we can have an operation in progress even if the buffer is empty, we call
     // backgroundFlushCommits at least one time.
     backgroundFlushCommits(true);
   }
 
   /**
    * Send the operations in the buffer to the servers. Does not wait for the server's answer. If
    * the is an error (max retried reach from a previous flush or bad operation), it tries to send
    * all operations in the buffer and sends an exception.
    *
    * @param synchronous - if true, sends all the writes and wait for all of them to finish before
    *        returning.
    */
   private void backgroundFlushCommits(boolean synchronous) throws
       InterruptedIOException,
       RetriesExhaustedWithDetailsException {
 
     LinkedList<Mutation> buffer = new LinkedList<>();
     // Keep track of the size so that this thread doesn't spin forever
     long dequeuedSize = 0;
 
     try {
       // Grab all of the available mutations.
       Mutation m;
 
       // If there's no buffer size drain everything. If there is a buffersize drain up to twice
       // that amount. This should keep the loop from continually spinning if there are threads
       // that keep adding more data to the buffer.
       while (
           (writeBufferSize <= 0 || dequeuedSize < (writeBufferSize * 2) || synchronous)
               && (m = writeAsyncBuffer.poll()) != null) {
         buffer.add(m);
         long size = m.heapSize();
         dequeuedSize += size;
         currentWriteBufferSize.addAndGet(-size);
       }
 
       if (!synchronous && dequeuedSize == 0) {
         return;
       }
 
       if (!synchronous) {
         ap.submit(tableName, buffer, true, null, false);
         if (ap.hasError()) {
           LOG.debug(tableName + ": One or more of the operations have failed -"
               + " waiting for all operation in progress to finish (successfully or not)");
         }
       }
       if (synchronous || ap.hasError()) {
         while (!buffer.isEmpty()) {
           ap.submit(tableName, buffer, true, null, false);
         }
         RetriesExhaustedWithDetailsException error =
             ap.waitForAllPreviousOpsAndReset(null, tableName.getNameAsString());
         if (error != null) {
           if (listener == null) {
             throw error;
           } else {
             this.listener.onException(error, this);
           }
         }
       }
     } finally {
       for (Mutation mut : buffer) {
         long size = mut.heapSize();
         currentWriteBufferSize.addAndGet(size);
         dequeuedSize -= size;
         writeAsyncBuffer.add(mut);
       }
     }
   }
 
   /**
    * This is used for legacy purposes in {@link HTable#setWriteBufferSize(long)} only. This ought
    * not be called for production uses.
    * @deprecated Going away when we drop public support for {@link HTableInterface}.
    */
   @Deprecated
   public void setWriteBufferSize(long writeBufferSize) throws RetriesExhaustedWithDetailsException,
       InterruptedIOException {
     this.writeBufferSize = writeBufferSize;
     if (currentWriteBufferSize.get() > writeBufferSize) {
       flush();
     }
   }
 
   /**
    * {@inheritDoc}
    */
   @Override
   public long getWriteBufferSize() {
     return this.writeBufferSize;
   }
 
   /**
    * This is used for legacy purposes in {@link HTable#getWriteBuffer()} only. This should not beÓ
    * called from production uses.
    * @deprecated Going away when we drop public support for {@link HTableInterface}.
 Ó   */
   @Deprecated
   public List<Row> getWriteBuffer() {
     return Arrays.asList(writeAsyncBuffer.toArray(new Row[0]));
   }
 }