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 import io.netty.buffer.ByteBuf;
19 import io.netty.buffer.ByteBufAllocator;
20
21 /**
22 * Allocates a new receive buffer whose capacity is probably large enough to read all inbound data and small enough
23 * not to waste its space.
24 */
25 public interface RecvByteBufAllocator {
26
27 /**
28 * Creates a new handle. The handle provides the actual operations and keeps the internal information which is
29 * required for predicting an optimal buffer capacity.
30 */
31 Handle newHandle();
32
33 interface Handle {
34 /**
35 * Creates a new receive buffer whose capacity is probably large enough to read all inbound data and small
36 * enough not to waste its space.
37 */
38 ByteBuf allocate(ByteBufAllocator alloc);
39
40 /**
41 * Similar to {@link #allocate(ByteBufAllocator)} except that it does not allocate anything but just tells the
42 * capacity.
43 */
44 int guess();
45
46 /**
47 * Records the the actual number of read bytes in the previous read operation so that the allocator allocates
48 * the buffer with potentially more correct capacity.
49 *
50 * @param actualReadBytes the actual number of read bytes in the previous read operation
51 */
52 void record(int actualReadBytes);
53 }
54 }