1 /*
2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.net.http;
27
28 import java.net.http.WSFrame.HeaderBuilder;
29 import java.net.http.WSFrame.Masker;
30 import java.net.http.WSOutgoingMessage.Binary;
31 import java.net.http.WSOutgoingMessage.Close;
32 import java.net.http.WSOutgoingMessage.Ping;
33 import java.net.http.WSOutgoingMessage.Pong;
34 import java.net.http.WSOutgoingMessage.Text;
35 import java.net.http.WSOutgoingMessage.Visitor;
36 import java.nio.ByteBuffer;
37 import java.nio.CharBuffer;
38 import java.nio.charset.CharacterCodingException;
39 import java.security.SecureRandom;
40 import java.util.function.Consumer;
41
42 import static java.net.http.WSFrame.MAX_HEADER_SIZE_BYTES;
43 import static java.net.http.WSFrame.Opcode.BINARY;
44 import static java.net.http.WSFrame.Opcode.CLOSE;
45 import static java.net.http.WSFrame.Opcode.CONTINUATION;
46 import static java.net.http.WSFrame.Opcode.PING;
47 import static java.net.http.WSFrame.Opcode.PONG;
48 import static java.net.http.WSFrame.Opcode.TEXT;
49 import static java.util.Objects.requireNonNull;
50
51 /*
52 * A Sender of outgoing messages. Given a message,
53 *
54 * 1) constructs the frame
55 * 2) initiates the channel write
56 * 3) notifies when the message has been sent
57 */
58 final class WSMessageSender {
59
60 private final Visitor frameBuilderVisitor;
61 private final Consumer<Throwable> completionEventConsumer;
62 private final WSWriter writer;
63 private final ByteBuffer[] buffers = new ByteBuffer[2];
64
65 WSMessageSender(RawChannel channel, Consumer<Throwable> completionEventConsumer) {
66 // Single reusable buffer that holds a header
67 this.buffers[0] = ByteBuffer.allocateDirect(MAX_HEADER_SIZE_BYTES);
68 this.frameBuilderVisitor = new FrameBuilderVisitor();
69 this.completionEventConsumer = completionEventConsumer;
70 this.writer = new WSWriter(channel, this.completionEventConsumer);
71 }
72
73 /*
74 * Tries to send the given message fully. Invoked once per message.
75 */
76 boolean trySendFully(WSOutgoingMessage m) {
77 requireNonNull(m);
78 synchronized (this) {
79 try {
80 return sendNow(m);
81 } catch (Exception e) {
82 completionEventConsumer.accept(e);
83 return false;
84 }
85 }
86 }
87
88 private boolean sendNow(WSOutgoingMessage m) {
89 buffers[0].clear();
90 m.accept(frameBuilderVisitor);
91 buffers[0].flip();
92 return writer.tryWriteFully(buffers);
93 }
94
95 /*
96 * Builds and initiates a write of a frame, from a given message.
97 */
98 class FrameBuilderVisitor implements Visitor {
99
100 private final SecureRandom random = new SecureRandom();
101 private final WSCharsetToolkit.Encoder encoder = new WSCharsetToolkit.Encoder();
102 private final Masker masker = new Masker();
103 private final HeaderBuilder headerBuilder = new HeaderBuilder();
104 private boolean previousIsLast = true;
105
106 @Override
107 public void visit(Text message) {
108 try {
109 buffers[1] = encoder.encode(CharBuffer.wrap(message.characters));
110 } catch (CharacterCodingException e) {
111 completionEventConsumer.accept(e);
112 return;
113 }
114 int mask = random.nextInt();
115 maskAndRewind(buffers[1], mask);
116 headerBuilder
117 .fin(message.isLast)
118 .opcode(previousIsLast ? TEXT : CONTINUATION)
119 .payloadLen(buffers[1].remaining())
120 .mask(mask)
121 .build(buffers[0]);
122 previousIsLast = message.isLast;
123 }
124
125 @Override
126 public void visit(Binary message) {
127 buffers[1] = message.bytes;
128 int mask = random.nextInt();
129 maskAndRewind(buffers[1], mask);
130 headerBuilder
131 .fin(message.isLast)
132 .opcode(previousIsLast ? BINARY : CONTINUATION)
133 .payloadLen(message.bytes.remaining())
134 .mask(mask)
135 .build(buffers[0]);
136 previousIsLast = message.isLast;
137 }
138
139 @Override
140 public void visit(Ping message) {
141 buffers[1] = message.bytes;
142 int mask = random.nextInt();
143 maskAndRewind(buffers[1], mask);
144 headerBuilder
145 .fin(true)
146 .opcode(PING)
147 .payloadLen(message.bytes.remaining())
148 .mask(mask)
149 .build(buffers[0]);
150 }
151
152 @Override
153 public void visit(Pong message) {
154 buffers[1] = message.bytes;
155 int mask = random.nextInt();
156 maskAndRewind(buffers[1], mask);
157 headerBuilder
158 .fin(true)
159 .opcode(PONG)
160 .payloadLen(message.bytes.remaining())
161 .mask(mask)
162 .build(buffers[0]);
163 }
164
165 @Override
166 public void visit(Close message) {
167 buffers[1] = message.bytes;
168 int mask = random.nextInt();
169 maskAndRewind(buffers[1], mask);
170 headerBuilder
171 .fin(true)
172 .opcode(CLOSE)
173 .payloadLen(buffers[1].remaining())
174 .mask(mask)
175 .build(buffers[0]);
176 }
177
178 private void maskAndRewind(ByteBuffer b, int mask) {
179 int oldPos = b.position();
180 masker.mask(mask).applyMask(b, b);
181 b.position(oldPos);
182 }
183 }
184 }