1 /*
2 * Copyright 2000-2004 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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.CharsetDecoder;
32 import java.nio.charset.CharsetEncoder;
33 import java.nio.charset.CoderResult;
34 import java.util.Arrays;
35
36 public class US_ASCII
37 extends Charset
38 implements HistoricallyNamedCharset
39 {
40
41 public US_ASCII() {
42 super("US-ASCII", StandardCharsets.aliases_US_ASCII);
43 }
44
45 public String historicalName() {
46 return "ASCII";
47 }
48
49 public boolean contains(Charset cs) {
50 return (cs instanceof US_ASCII);
51 }
52
53 public CharsetDecoder newDecoder() {
54 return new Decoder(this);
55 }
56
57 public CharsetEncoder newEncoder() {
58 return new Encoder(this);
59 }
60
61 private static class Decoder extends CharsetDecoder
62 implements ArrayDecoder {
63
64 private Decoder(Charset cs) {
65 super(cs, 1.0f, 1.0f);
66 }
67
68 private CoderResult decodeArrayLoop(ByteBuffer src,
69 CharBuffer dst)
70 {
71 byte[] sa = src.array();
72 int sp = src.arrayOffset() + src.position();
73 int sl = src.arrayOffset() + src.limit();
74 assert (sp <= sl);
75 sp = (sp <= sl ? sp : sl);
76 char[] da = dst.array();
77 int dp = dst.arrayOffset() + dst.position();
78 int dl = dst.arrayOffset() + dst.limit();
79 assert (dp <= dl);
80 dp = (dp <= dl ? dp : dl);
81
82 try {
83 while (sp < sl) {
84 byte b = sa[sp];
85 if (b >= 0) {
86 if (dp >= dl)
87 return CoderResult.OVERFLOW;
88 da[dp++] = (char)b;
89 sp++;
90 continue;
91 }
92 return CoderResult.malformedForLength(1);
93 }
94 return CoderResult.UNDERFLOW;
95 } finally {
96 src.position(sp - src.arrayOffset());
97 dst.position(dp - dst.arrayOffset());
98 }
99 }
100
101 private CoderResult decodeBufferLoop(ByteBuffer src,
102 CharBuffer dst)
103 {
104 int mark = src.position();
105 try {
106 while (src.hasRemaining()) {
107 byte b = src.get();
108 if (b >= 0) {
109 if (!dst.hasRemaining())
110 return CoderResult.OVERFLOW;
111 dst.put((char)b);
112 mark++;
113 continue;
114 }
115 return CoderResult.malformedForLength(1);
116 }
117 return CoderResult.UNDERFLOW;
118 } finally {
119 src.position(mark);
120 }
121 }
122
123 protected CoderResult decodeLoop(ByteBuffer src,
124 CharBuffer dst)
125 {
126 if (src.hasArray() && dst.hasArray())
127 return decodeArrayLoop(src, dst);
128 else
129 return decodeBufferLoop(src, dst);
130 }
131
132 private char repl = '\uFFFD';
133 protected void implReplaceWith(String newReplacement) {
134 repl = newReplacement.charAt(0);
135 }
136
137 public int decode(byte[] src, int sp, int len, char[] dst) {
138 int dp = 0;
139 len = Math.min(len, dst.length);
140 while (dp < len) {
141 byte b = src[sp++];
142 if (b >= 0)
143 dst[dp++] = (char)b;
144 else
145 dst[dp++] = repl;
146 }
147 return dp;
148 }
149 }
150
151 private static class Encoder extends CharsetEncoder
152 implements ArrayEncoder {
153
154 private Encoder(Charset cs) {
155 super(cs, 1.0f, 1.0f);
156 }
157
158 public boolean canEncode(char c) {
159 return c < 0x80;
160 }
161
162 public boolean isLegalReplacement(byte[] repl) {
163 return (repl.length == 1 && repl[0] >= 0);
164 }
165
166 private final Surrogate.Parser sgp = new Surrogate.Parser();
167 private CoderResult encodeArrayLoop(CharBuffer src,
168 ByteBuffer dst)
169 {
170 char[] sa = src.array();
171 int sp = src.arrayOffset() + src.position();
172 int sl = src.arrayOffset() + src.limit();
173 assert (sp <= sl);
174 sp = (sp <= sl ? sp : sl);
175 byte[] da = dst.array();
176 int dp = dst.arrayOffset() + dst.position();
177 int dl = dst.arrayOffset() + dst.limit();
178 assert (dp <= dl);
179 dp = (dp <= dl ? dp : dl);
180
181 try {
182 while (sp < sl) {
183 char c = sa[sp];
184 if (c < 0x80) {
185 if (dp >= dl)
186 return CoderResult.OVERFLOW;
187 da[dp] = (byte)c;
188 sp++; dp++;
189 continue;
190 }
191 if (sgp.parse(c, sa, sp, sl) < 0)
192 return sgp.error();
193 return sgp.unmappableResult();
194 }
195 return CoderResult.UNDERFLOW;
196 } finally {
197 src.position(sp - src.arrayOffset());
198 dst.position(dp - dst.arrayOffset());
199 }
200 }
201
202 private CoderResult encodeBufferLoop(CharBuffer src,
203 ByteBuffer dst)
204 {
205 int mark = src.position();
206 try {
207 while (src.hasRemaining()) {
208 char c = src.get();
209 if (c < 0x80) {
210 if (!dst.hasRemaining())
211 return CoderResult.OVERFLOW;
212 dst.put((byte)c);
213 mark++;
214 continue;
215 }
216 if (sgp.parse(c, src) < 0)
217 return sgp.error();
218 return sgp.unmappableResult();
219 }
220 return CoderResult.UNDERFLOW;
221 } finally {
222 src.position(mark);
223 }
224 }
225
226 protected CoderResult encodeLoop(CharBuffer src,
227 ByteBuffer dst)
228 {
229 if (src.hasArray() && dst.hasArray())
230 return encodeArrayLoop(src, dst);
231 else
232 return encodeBufferLoop(src, dst);
233 }
234
235 private byte repl = (byte)'?';
236 protected void implReplaceWith(byte[] newReplacement) {
237 repl = newReplacement[0];
238 }
239
240 public int encode(char[] src, int sp, int len, byte[] dst) {
241 int dp = 0;
242 int sl = sp + Math.min(len, dst.length);
243 while (sp < sl) {
244 char c = src[sp++];
245 if (c < 0x80) {
246 dst[dp++] = (byte)c;
247 continue;
248 }
249 if (Surrogate.isHigh(c) && sp < sl &&
250 Surrogate.isLow(src[sp])) {
251 if (len > dst.length) {
252 sl++;
253 len--;
254 }
255 sp++;
256 }
257 dst[dp++] = repl;
258 }
259 return dp;
260 }
261 }
262
263 }