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    1   /*
    2    *  Licensed to the Apache Software Foundation (ASF) under one
    3    *  or more contributor license agreements.  See the NOTICE file
    4    *  distributed with this work for additional information
    5    *  regarding copyright ownership.  The ASF licenses this file
    6    *  to you under the Apache License, Version 2.0 (the
    7    *  "License"); you may not use this file except in compliance
    8    *  with the License.  You may obtain a copy of the License at
    9    *
    10   *    http://www.apache.org/licenses/LICENSE-2.0
    11   *
    12   *  Unless required by applicable law or agreed to in writing,
    13   *  software distributed under the License is distributed on an
    14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    15   *  KIND, either express or implied.  See the License for the
    16   *  specific language governing permissions and limitations
    17   *  under the License.
    18   *
    19   */
    20  package org.apache.mina.filter.codec.support;
    21
    22  import java.util.LinkedList;
    23  import java.util.Queue;
    24
    25  import org.apache.mina.common.ByteBuffer;
    26  import org.apache.mina.common.WriteFuture;
    27  import org.apache.mina.filter.codec.ProtocolEncoderOutput;
    28
    29  /**
    30   * A {@link ProtocolEncoderOutput} based on queue.
    31   *
    32   * @author The Apache Directory Project (mina-dev@directory.apache.org)
    33   * @version $Rev: 555855 $, $Date: 2007-07-13 05:19:00 +0200 (Fri, 13 Jul 2007) $
    34   */
    35  public abstract class SimpleProtocolEncoderOutput implements
    36          ProtocolEncoderOutput {
    37      private final Queue<ByteBuffer> bufferQueue = new LinkedList<ByteBuffer>();
    38
    39      public SimpleProtocolEncoderOutput() {
    40      }
    41
    42      public Queue<ByteBuffer> getBufferQueue() {
    43          return bufferQueue;
    44      }
    45
    46      public void write(ByteBuffer buf) {
    47          bufferQueue.add(buf);
    48      }
    49
    50      public void mergeAll() {
    51          int sum = 0;
    52          final int size = bufferQueue.size();
    53
    54          if (size < 2) {
    55              // no need to merge!
    56              return;
    57          }
    58
    59          // Get the size of merged BB
    60          for (Object o : bufferQueue) {
    61              sum += ((ByteBuffer) o).remaining();
    62          }
    63
    64          // Allocate a new BB that will contain all fragments
    65          ByteBuffer newBuf = ByteBuffer.allocate(sum);
    66
    67          // and merge all.
    68          for (;;) {
    69              ByteBuffer buf = bufferQueue.poll();
    70              if (buf == null) {
    71                  break;
    72              }
    73
    74              newBuf.put(buf);
    75              buf.release();
    76          }
    77
    78          // Push the new buffer finally.
    79          newBuf.flip();
    80          bufferQueue.offer(newBuf);
    81      }
    82
    83      public WriteFuture flush() {
    84          Queue<ByteBuffer> bufferQueue = this.bufferQueue;
    85          WriteFuture future = null;
    86          if (bufferQueue.isEmpty()) {
    87              return null;
    88          } else {
    89              for (;;) {
    90                  ByteBuffer buf = bufferQueue.poll();
    91                  if (buf == null) {
    92                      break;
    93                  }
    94
    95                  // Flush only when the buffer has remaining.
    96                  if (buf.hasRemaining()) {
    97                      future = doFlush(buf);
    98                  }
    99              }
    100         }
    101
    102         return future;
    103     }
    104
    105     protected abstract WriteFuture doFlush(ByteBuffer buf);
    106 }