1 /*
2 * Copyright (c) 2005, 2010, 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 sun.nio.cs;
27
28 import java.nio.ByteBuffer;
29 import java.nio.CharBuffer;
30 import java.nio.charset.Charset;
31 import java.nio.charset.CoderResult;
32 import java.nio.charset.CharsetDecoder;
33 import java.nio.charset.CharsetEncoder;
34
35 class UTF_32Coder {
36 protected static final int BOM_BIG = 0xFEFF;
37 protected static final int BOM_LITTLE = 0xFFFE0000;
38 protected static final int NONE = 0;
39 protected static final int BIG = 1;
40 protected static final int LITTLE = 2;
41
42 protected static class Decoder extends CharsetDecoder {
43 private int currentBO;
44 private int expectedBO;
45
46 protected Decoder(Charset cs, int bo) {
47 super(cs, 0.25f, 1.0f);
48 this.expectedBO = bo;
49 this.currentBO = NONE;
50 }
51
52 private int getCP(ByteBuffer src) {
53 return (currentBO==BIG)
54 ?(((src.get() & 0xff) << 24) |
55 ((src.get() & 0xff) << 16) |
56 ((src.get() & 0xff) << 8) |
57 (src.get() & 0xff))
58 :((src.get() & 0xff) |
59 ((src.get() & 0xff) << 8) |
60 ((src.get() & 0xff) << 16) |
61 ((src.get() & 0xff) << 24));
62 }
63
64 protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {
65 if (src.remaining() < 4)
66 return CoderResult.UNDERFLOW;
67 int mark = src.position();
68 int cp;
69 try {
70 if (currentBO == NONE) {
71 cp = ((src.get() & 0xff) << 24) |
72 ((src.get() & 0xff) << 16) |
73 ((src.get() & 0xff) << 8) |
74 (src.get() & 0xff);
75 if (cp == BOM_BIG && expectedBO != LITTLE) {
76 currentBO = BIG;
77 mark += 4;
78 } else if (cp == BOM_LITTLE && expectedBO != BIG) {
79 currentBO = LITTLE;
80 mark += 4;
81 } else {
82 if (expectedBO == NONE)
83 currentBO = BIG;
84 else
85 currentBO = expectedBO;
86 src.position(mark);
87 }
88 }
89 while (src.remaining() >= 4) {
90 cp = getCP(src);
91 if (Character.isBmpCodePoint(cp)) {
92 if (!dst.hasRemaining())
93 return CoderResult.OVERFLOW;
94 mark += 4;
95 dst.put((char) cp);
96 } else if (Character.isValidCodePoint(cp)) {
97 if (dst.remaining() < 2)
98 return CoderResult.OVERFLOW;
99 mark += 4;
100 dst.put(Character.highSurrogate(cp));
101 dst.put(Character.lowSurrogate(cp));
102 } else {
103 return CoderResult.malformedForLength(4);
104 }
105 }
106 return CoderResult.UNDERFLOW;
107 } finally {
108 src.position(mark);
109 }
110 }
111 protected void implReset() {
112 currentBO = NONE;
113 }
114 }
115
116 protected static class Encoder extends CharsetEncoder {
117 private boolean doBOM = false;
118 private boolean doneBOM = true;
119 private int byteOrder;
120
121 protected void put(int cp, ByteBuffer dst) {
122 if (byteOrder==BIG) {
123 dst.put((byte)(cp >> 24));
124 dst.put((byte)(cp >> 16));
125 dst.put((byte)(cp >> 8));
126 dst.put((byte)cp);
127 } else {
128 dst.put((byte)cp);
129 dst.put((byte)(cp >> 8));
130 dst.put((byte)(cp >> 16));
131 dst.put((byte)(cp >> 24));
132 }
133 }
134
135 protected Encoder(Charset cs, int byteOrder, boolean doBOM) {
136 super(cs, 4.0f,
137 doBOM?8.0f:4.0f,
138 (byteOrder==BIG)?new byte[]{(byte)0, (byte)0, (byte)0xff, (byte)0xfd}
139 :new byte[]{(byte)0xfd, (byte)0xff, (byte)0, (byte)0});
140 this.byteOrder = byteOrder;
141 this.doBOM = doBOM;
142 this.doneBOM = !doBOM;
143 }
144
145 protected CoderResult encodeLoop(CharBuffer src, ByteBuffer dst) {
146 int mark = src.position();
147 if (!doneBOM && src.hasRemaining()) {
148 if (dst.remaining() < 4)
149 return CoderResult.OVERFLOW;
150 put(BOM_BIG, dst);
151 doneBOM = true;
152 }
153 try {
154 while (src.hasRemaining()) {
155 char c = src.get();
156 if (!Character.isSurrogate(c)) {
157 if (dst.remaining() < 4)
158 return CoderResult.OVERFLOW;
159 mark++;
160 put(c, dst);
161 } else if (Character.isHighSurrogate(c)) {
162 if (!src.hasRemaining())
163 return CoderResult.UNDERFLOW;
164 char low = src.get();
165 if (Character.isLowSurrogate(low)) {
166 if (dst.remaining() < 4)
167 return CoderResult.OVERFLOW;
168 mark += 2;
169 put(Character.toCodePoint(c, low), dst);
170 } else {
171 return CoderResult.malformedForLength(1);
172 }
173 } else {
174 // assert Character.isLowSurrogate(c);
175 return CoderResult.malformedForLength(1);
176 }
177 }
178 return CoderResult.UNDERFLOW;
179 } finally {
180 src.position(mark);
181 }
182 }
183
184 protected void implReset() {
185 doneBOM = !doBOM;
186 }
187
188 }
189 }