1 /*
2 * Copyright (c) 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 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 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 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 package java.net.http;
26
27 import java.net.http.WSFrame.HeaderBuilder;
28 import java.net.http.WSFrame.Masker;
29 import java.net.http.WSOutgoingMessage.Binary;
30 import java.net.http.WSOutgoingMessage.Close;
31 import java.net.http.WSOutgoingMessage.Ping;
32 import java.net.http.WSOutgoingMessage.Pong;
33 import java.net.http.WSOutgoingMessage.Text;
34 import java.net.http.WSOutgoingMessage.Visitor;
35 import java.nio.ByteBuffer;
36 import java.nio.CharBuffer;
37 import java.nio.charset.CharacterCodingException;
38 import java.security.SecureRandom;
39 import java.util.function.Consumer;
40
41 import static java.net.http.WSFrame.MAX_HEADER_SIZE_BYTES;
42 import static java.net.http.WSFrame.Opcode.BINARY;
43 import static java.net.http.WSFrame.Opcode.CLOSE;
44 import static java.net.http.WSFrame.Opcode.CONTINUATION;
45 import static java.net.http.WSFrame.Opcode.PING;
46 import static java.net.http.WSFrame.Opcode.PONG;
47 import static java.net.http.WSFrame.Opcode.TEXT;
48 import static java.util.Objects.requireNonNull;
49
50 /*
51 * A Sender of outgoing messages. Given a message,
52 *
53 * 1) constructs the frame
54 * 2) initiates the channel write
55 * 3) notifies when the message has been sent
56 */
57 final class WSMessageSender {
58
59 private final Visitor frameBuilderVisitor;
60 private final Consumer<Throwable> completionEventConsumer;
61 private final WSWriter writer;
62 private final ByteBuffer[] buffers = new ByteBuffer[2];
63
64 WSMessageSender(RawChannel channel, Consumer<Throwable> completionEventConsumer) {
65 // Single reusable buffer that holds a header
66 this.buffers[0] = ByteBuffer.allocateDirect(MAX_HEADER_SIZE_BYTES);
67 this.frameBuilderVisitor = new FrameBuilderVisitor();
68 this.completionEventConsumer = completionEventConsumer;
69 this.writer = new WSWriter(channel, this.completionEventConsumer);
70 }
71
72 /*
73 * Tries to send the given message fully. Invoked once per message.
74 */
75 boolean trySendFully(WSOutgoingMessage m) {
76 requireNonNull(m);
77 synchronized (this) {
78 try {
79 return sendNow(m);
80 } catch (Exception e) {
81 completionEventConsumer.accept(e);
82 return false;
83 }
84 }
85 }
86
87 private boolean sendNow(WSOutgoingMessage m) {
88 buffers[0].clear();
89 m.accept(frameBuilderVisitor);
90 buffers[0].flip();
91 return writer.tryWriteFully(buffers);
92 }
93
94 /*
95 * Builds and initiates a write of a frame, from a given message.
96 */
97 class FrameBuilderVisitor implements Visitor {
98
99 private final SecureRandom random = new SecureRandom();
100 private final WSCharsetToolkit.Encoder encoder = new WSCharsetToolkit.Encoder();
101 private final Masker masker = new Masker();
102 private final HeaderBuilder headerBuilder = new HeaderBuilder();
103 private boolean previousIsLast = true;
104
105 @Override
106 public void visit(Text message) {
107 try {
108 buffers[1] = encoder.encode(CharBuffer.wrap(message.characters));
109 } catch (CharacterCodingException e) {
110 completionEventConsumer.accept(e);
111 return;
112 }
113 int mask = random.nextInt();
114 maskAndRewind(buffers[1], mask);
115 headerBuilder
116 .fin(message.isLast)
117 .opcode(previousIsLast ? TEXT : CONTINUATION)
118 .payloadLen(buffers[1].remaining())
119 .mask(mask)
120 .build(buffers[0]);
121 previousIsLast = message.isLast;
122 }
123
124 @Override
125 public void visit(Binary message) {
126 buffers[1] = message.bytes;
127 int mask = random.nextInt();
128 maskAndRewind(buffers[1], mask);
129 headerBuilder
130 .fin(message.isLast)
131 .opcode(previousIsLast ? BINARY : CONTINUATION)
132 .payloadLen(message.bytes.remaining())
133 .mask(mask)
134 .build(buffers[0]);
135 previousIsLast = message.isLast;
136 }
137
138 @Override
139 public void visit(Ping message) {
140 buffers[1] = message.bytes;
141 int mask = random.nextInt();
142 maskAndRewind(buffers[1], mask);
143 headerBuilder
144 .fin(true)
145 .opcode(PING)
146 .payloadLen(message.bytes.remaining())
147 .mask(mask)
148 .build(buffers[0]);
149 }
150
151 @Override
152 public void visit(Pong message) {
153 buffers[1] = message.bytes;
154 int mask = random.nextInt();
155 maskAndRewind(buffers[1], mask);
156 headerBuilder
157 .fin(true)
158 .opcode(PONG)
159 .payloadLen(message.bytes.remaining())
160 .mask(mask)
161 .build(buffers[0]);
162 }
163
164 @Override
165 public void visit(Close message) {
166 buffers[1] = message.bytes;
167 int mask = random.nextInt();
168 maskAndRewind(buffers[1], mask);
169 headerBuilder
170 .fin(true)
171 .opcode(CLOSE)
172 .payloadLen(buffers[1].remaining())
173 .mask(mask)
174 .build(buffers[0]);
175 }
176
177 private void maskAndRewind(ByteBuffer b, int mask) {
178 int oldPos = b.position();
179 masker.mask(mask).applyMask(b, b);
180 b.position(oldPos);
181 }
182 }
183 }