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.hc.core5.http.impl.nio;
29
30 import java.io.IOException;
31 import java.nio.ByteBuffer;
32 import java.nio.channels.ReadableByteChannel;
33 import java.util.List;
34
35 import org.apache.hc.core5.http.Header;
36 import org.apache.hc.core5.http.impl.BasicHttpTransportMetrics;
37 import org.apache.hc.core5.http.nio.ContentDecoder;
38 import org.apache.hc.core5.http.nio.SessionInputBuffer;
39 import org.apache.hc.core5.util.Args;
40
41 /**
42 * Abstract {@link ContentDecoder} that serves as a base for all content
43 * decoder implementations.
44 *
45 * @since 4.0
46 */
47 public abstract class AbstractContentDecoder implements ContentDecoder {
48
49 final ReadableByteChannel channel;
50 final SessionInputBuffer buffer;
51 final BasicHttpTransportMetrics metrics;
52
53 protected boolean completed;
54
55 /**
56 * Creates an instance of this class.
57 *
58 * @param channel the source channel.
59 * @param buffer the session input buffer that can be used to store
60 * session data for intermediate processing.
61 * @param metrics Transport metrics of the underlying HTTP transport.
62 */
63 public AbstractContentDecoder(
64 final ReadableByteChannel channel,
65 final SessionInputBuffer buffer,
66 final BasicHttpTransportMetrics metrics) {
67 super();
68 Args.notNull(channel, "Channel");
69 Args.notNull(buffer, "Session input buffer");
70 Args.notNull(metrics, "Transport metrics");
71 this.buffer = buffer;
72 this.channel = channel;
73 this.metrics = metrics;
74 }
75
76 protected ReadableByteChannel channel() {
77 return this.channel;
78 }
79
80 protected SessionInputBuffer buffer() {
81 return this.buffer;
82 }
83
84 protected BasicHttpTransportMetrics metrics() {
85 return this.metrics;
86 }
87
88 @Override
89 public boolean isCompleted() {
90 return this.completed;
91 }
92
93 /**
94 * Sets the completed status of this decoder. 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 * @param completed the completed status of this decoder.
101 * @since 4.4.11
102 */
103 public void setCompleted(final boolean completed) {
104 this.completed = completed;
105 }
106
107 /**
108 * Sets the completed status of this decoder to true. Normally this is not necessary
109 * (the decoder will automatically complete when the underlying channel
110 * returns EOF). It is useful to mark the decoder as completed if you have
111 * some other means to know all the necessary data has been read and want to
112 * reuse the underlying connection for more messages.
113 *
114 * @since 4.4.11
115 */
116 protected void setCompleted() {
117 this.completed = true;
118 }
119
120 /**
121 * Reads from the channel to the destination.
122 *
123 * @param dst destination.
124 * @return number of bytes transferred.
125 * @throws IOException If an I/O error occurs.
126 *
127 * @since 4.3
128 */
129 protected int readFromChannel(final ByteBuffer dst) throws IOException {
130 final int bytesRead = this.channel.read(dst);
131 if (bytesRead > 0) {
132 this.metrics.incrementBytesTransferred(bytesRead);
133 }
134 return bytesRead;
135 }
136
137 /**
138 * Reads from the channel to the session buffer.
139 *
140 * @return number of bytes transferred, possibly zero, or {@code -1} if the channel has reached end-of-stream.
141 * @throws IOException If an I/O error occurs.
142 *
143 * @since 4.3
144 */
145 protected int fillBufferFromChannel() throws IOException {
146 final int bytesRead = this.buffer.fill(this.channel);
147 if (bytesRead > 0) {
148 this.metrics.incrementBytesTransferred(bytesRead);
149 }
150 return bytesRead;
151 }
152
153 /**
154 * Reads from the channel to the destination.
155 *
156 * @param dst destination.
157 * @param limit max number of bytes to transfer.
158 * @return number of bytes transferred, possibly zero, or {@code -1} if the channel has reached end-of-stream.
159 * @throws IOException If an I/O error occurs.
160 *
161 * @since 4.3
162 */
163 protected int readFromChannel(final ByteBuffer dst, final int limit) throws IOException {
164 final int bytesRead;
165 if (dst.remaining() > limit) {
166 final int oldLimit = dst.limit();
167 final int newLimit = oldLimit - (dst.remaining() - limit);
168 dst.limit(newLimit);
169 bytesRead = this.channel.read(dst);
170 dst.limit(oldLimit);
171 } else {
172 bytesRead = this.channel.read(dst);
173 }
174 if (bytesRead > 0) {
175 this.metrics.incrementBytesTransferred(bytesRead);
176 }
177 return bytesRead;
178 }
179
180 @Override
181 public List<? extends Header> getTrailers() {
182 return null;
183 }
184
185 }