1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.http.impl.nio.codecs;
29
30 import java.io.IOException;
31 import java.nio.ByteBuffer;
32 import java.nio.channels.ReadableByteChannel;
33
34 import org.apache.http.impl.io.HttpTransportMetricsImpl;
35 import org.apache.http.nio.ContentDecoder;
36 import org.apache.http.nio.reactor.SessionInputBuffer;
37 import org.apache.http.util.Args;
38
39 /**
40 * Abstract {@link ContentDecoder} that serves as a base for all content
41 * decoder implementations.
42 *
43 * @since 4.0
44 */
45 public abstract class AbstractContentDecoder implements ContentDecoder {
46
47 protected final ReadableByteChannel channel;
48 protected final SessionInputBuffer buffer;
49 protected final HttpTransportMetricsImpl metrics;
50
51 protected boolean completed;
52
53 /**
54 * Creates an instance of this class.
55 *
56 * @param channel the source channel.
57 * @param buffer the session input buffer that can be used to store
58 * session data for intermediate processing.
59 * @param metrics Transport metrics of the underlying HTTP transport.
60 */
61 public AbstractContentDecoder(
62 final ReadableByteChannel channel,
63 final SessionInputBuffer buffer,
64 final HttpTransportMetricsImpl metrics) {
65 super();
66 Args.notNull(channel, "Channel");
67 Args.notNull(buffer, "Session input buffer");
68 Args.notNull(metrics, "Transport metrics");
69 this.buffer = buffer;
70 this.channel = channel;
71 this.metrics = metrics;
72 }
73
74 @Override
75 public boolean isCompleted() {
76 return this.completed;
77 }
78
79 /**
80 * Sets the completed status of this decoder. Normally this is not necessary
81 * (the decoder will automatically complete when the underlying channel
82 * returns EOF). It is useful to mark the decoder as completed if you have
83 * some other means to know all the necessary data has been read and want to
84 * reuse the underlying connection for more messages.
85 *
86 * @param completed the completed status of this decoder.
87 * @since 4.4.11
88 */
89 public void setCompleted(final boolean completed) {
90 this.completed = completed;
91 }
92
93 /**
94 * Sets the completed status of this decoder to true. Normally this is not necessary
95 * (the decoder will automatically complete when the underlying channel
96 * returns EOF). It is useful to mark the decoder as completed if you have
97 * some other means to know all the necessary data has been read and want to
98 * reuse the underlying connection for more messages.
99 *
100 * @since 4.4.11
101 */
102 protected void setCompleted() {
103 this.completed = true;
104 }
105
106 /**
107 * Reads from the channel to the destination.
108 *
109 * @param dst destination.
110 * @return number of bytes transferred.
111 *
112 * @since 4.3
113 */
114 protected int readFromChannel(final ByteBuffer dst) throws IOException {
115 final int bytesRead = this.channel.read(dst);
116 if (bytesRead > 0) {
117 this.metrics.incrementBytesTransferred(bytesRead);
118 }
119 return bytesRead;
120 }
121
122 /**
123 * Reads from the channel to the session buffer.
124 * @return number of bytes transferred.
125 *
126 * @since 4.3
127 */
128 protected int fillBufferFromChannel() throws IOException {
129 final int bytesRead = this.buffer.fill(this.channel);
130 if (bytesRead > 0) {
131 this.metrics.incrementBytesTransferred(bytesRead);
132 }
133 return bytesRead;
134 }
135
136 /**
137 * Reads from the channel to the destination.
138 *
139 * @param dst destination.
140 * @param limit max number of bytes to transfer.
141 * @return number of bytes transferred.
142 *
143 * @since 4.3
144 */
145 protected int readFromChannel(final ByteBuffer dst, final int limit) throws IOException {
146 final int bytesRead;
147 if (dst.remaining() > limit) {
148 final int oldLimit = dst.limit();
149 final int newLimit = oldLimit - (dst.remaining() - limit);
150 dst.limit(newLimit);
151 bytesRead = this.channel.read(dst);
152 dst.limit(oldLimit);
153 } else {
154 bytesRead = this.channel.read(dst);
155 }
156 if (bytesRead > 0) {
157 this.metrics.incrementBytesTransferred(bytesRead);
158 }
159 return bytesRead;
160 }
161
162 }