View Javadoc
1   /*
2    * Copyright 2012 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package io.netty.channel;
17  
18  /**
19   * The {@link RecvByteBufAllocator} that always yields the same buffer
20   * size prediction.  This predictor ignores the feed back from the I/O thread.
21   */
22  public class FixedRecvByteBufAllocator extends DefaultMaxMessagesRecvByteBufAllocator {
23  
24      private final int bufferSize;
25  
26      private final class HandleImpl extends MaxMessageHandle {
27          private final int bufferSize;
28  
29          public HandleImpl(int bufferSize) {
30              this.bufferSize = bufferSize;
31          }
32  
33          @Override
34          public int guess() {
35              return bufferSize;
36          }
37      }
38  
39      /**
40       * Creates a new predictor that always returns the same prediction of
41       * the specified buffer size.
42       */
43      public FixedRecvByteBufAllocator(int bufferSize) {
44          if (bufferSize <= 0) {
45              throw new IllegalArgumentException(
46                      "bufferSize must greater than 0: " + bufferSize);
47          }
48          this.bufferSize = bufferSize;
49      }
50  
51      @SuppressWarnings("deprecation")
52      @Override
53      public Handle newHandle() {
54          return new HandleImpl(bufferSize);
55      }
56  
57      @Override
58      public FixedRecvByteBufAllocator respectMaybeMoreData(boolean respectMaybeMoreData) {
59          super.respectMaybeMoreData(respectMaybeMoreData);
60          return this;
61      }
62  }