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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;
    21
    22  import java.util.Queue;
    23  import java.util.concurrent.ConcurrentLinkedQueue;
    24
    25  import org.apache.mina.core.buffer.IoBuffer;
    26
    27  /**
    28   * A {@link ProtocolEncoderOutput} based on queue.
    29   *
    30   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
    31   */
    32  public abstract class AbstractProtocolEncoderOutput implements ProtocolEncoderOutput {
    33      private final Queue<Object> messageQueue = new ConcurrentLinkedQueue<Object>();
    34
    35      private boolean buffersOnly = true;
    36
    37      public AbstractProtocolEncoderOutput() {
    38          // Do nothing
    39      }
    40
    41      public Queue<Object> getMessageQueue() {
    42          return messageQueue;
    43      }
    44
    45      public void write(Object encodedMessage) {
    46          if (encodedMessage instanceof IoBuffer) {
    47              IoBuffer buf = (IoBuffer) encodedMessage;
    48              if (buf.hasRemaining()) {
    49                  messageQueue.offer(buf);
    50              } else {
    51                  throw new IllegalArgumentException("buf is empty. Forgot to call flip()?");
    52              }
    53          } else {
    54              messageQueue.offer(encodedMessage);
    55              buffersOnly = false;
    56          }
    57      }
    58
    59      public void mergeAll() {
    60          if (!buffersOnly) {
    61              throw new IllegalStateException("the encoded message list contains a non-buffer.");
    62          }
    63
    64          final int size = messageQueue.size();
    65
    66          if (size < 2) {
    67              // no need to merge!
    68              return;
    69          }
    70
    71          // Get the size of merged BB
    72          int sum = 0;
    73          for (Object b : messageQueue) {
    74              sum += ((IoBuffer) b).remaining();
    75          }
    76
    77          // Allocate a new BB that will contain all fragments
    78          IoBuffer newBuf = IoBuffer.allocate(sum);
    79
    80          // and merge all.
    81          for (;;) {
    82              IoBuffer buf = (IoBuffer) messageQueue.poll();
    83              if (buf == null) {
    84                  break;
    85              }
    86
    87              newBuf.put(buf);
    88          }
    89
    90          // Push the new buffer finally.
    91          newBuf.flip();
    92          messageQueue.add(newBuf);
    93      }
    94  }