SingleByte.java revision 12745:f068a4ffddd2 
1/*
2 * Copyright (c) 2008, 2012, 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
26package sun.nio.cs;
27
28import java.nio.Buffer;
29import java.nio.ByteBuffer;
30import java.nio.CharBuffer;
31import java.nio.charset.Charset;
32import java.nio.charset.CharsetDecoder;
33import java.nio.charset.CharsetEncoder;
34import java.nio.charset.CoderResult;
35import java.util.Arrays;
36import static sun.nio.cs.CharsetMapping.*;
37
38public class SingleByte
39{
40    private static final CoderResult withResult(CoderResult cr,
41                                                Buffer src, int sp,
42                                                Buffer dst, int dp)
43    {
44        src.position(sp - src.arrayOffset());
45        dst.position(dp - dst.arrayOffset());
46        return cr;
47    }
48
49    public static final class Decoder extends CharsetDecoder
50                                      implements ArrayDecoder {
51        private final char[] b2c;
52
53        public Decoder(Charset cs, char[] b2c) {
54            super(cs, 1.0f, 1.0f);
55            this.b2c = b2c;
56        }
57
58        private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) {
59            byte[] sa = src.array();
60            int sp = src.arrayOffset() + src.position();
61            int sl = src.arrayOffset() + src.limit();
62
63            char[] da = dst.array();
64            int dp = dst.arrayOffset() + dst.position();
65            int dl = dst.arrayOffset() + dst.limit();
66
67            CoderResult cr = CoderResult.UNDERFLOW;
68            if ((dl - dp) < (sl - sp)) {
69                sl = sp + (dl - dp);
70                cr = CoderResult.OVERFLOW;
71            }
72
73            while (sp < sl) {
74                char c = decode(sa[sp]);
75                if (c == UNMAPPABLE_DECODING) {
76                    return withResult(CoderResult.unmappableForLength(1),
77                               src, sp, dst, dp);
78                }
79                da[dp++] = c;
80                sp++;
81            }
82            return withResult(cr, src, sp, dst, dp);
83        }
84
85        private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {
86            int mark = src.position();
87            try {
88                while (src.hasRemaining()) {
89                    char c = decode(src.get());
90                    if (c == UNMAPPABLE_DECODING)
91                        return CoderResult.unmappableForLength(1);
92                    if (!dst.hasRemaining())
93                        return CoderResult.OVERFLOW;
94                    dst.put(c);
95                    mark++;
96                }
97                return CoderResult.UNDERFLOW;
98            } finally {
99                src.position(mark);
100            }
101        }
102
103        protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {
104            if (src.hasArray() && dst.hasArray())
105                return decodeArrayLoop(src, dst);
106            else
107                return decodeBufferLoop(src, dst);
108        }
109
110        public final char decode(int b) {
111            return b2c[b + 128];
112        }
113
114        private char repl = '\uFFFD';
115        protected void implReplaceWith(String newReplacement) {
116            repl = newReplacement.charAt(0);
117        }
118
119        public int decode(byte[] src, int sp, int len, char[] dst) {
120            if (len > dst.length)
121                len = dst.length;
122            int dp = 0;
123            while (dp < len) {
124                dst[dp] = decode(src[sp++]);
125                if (dst[dp] == UNMAPPABLE_DECODING) {
126                    dst[dp] = repl;
127                }
128                dp++;
129            }
130            return dp;
131        }
132    }
133
134    public static final class Encoder extends CharsetEncoder
135                                      implements ArrayEncoder {
136        private Surrogate.Parser sgp;
137        private final char[] c2b;
138        private final char[] c2bIndex;
139
140        public Encoder(Charset cs, char[] c2b, char[] c2bIndex) {
141            super(cs, 1.0f, 1.0f);
142            this.c2b = c2b;
143            this.c2bIndex = c2bIndex;
144        }
145
146        public boolean canEncode(char c) {
147            return encode(c) != UNMAPPABLE_ENCODING;
148        }
149
150        public boolean isLegalReplacement(byte[] repl) {
151            return ((repl.length == 1 && repl[0] == (byte)'?') ||
152                    super.isLegalReplacement(repl));
153        }
154
155        private CoderResult encodeArrayLoop(CharBuffer src, ByteBuffer dst) {
156            char[] sa = src.array();
157            int sp = src.arrayOffset() + src.position();
158            int sl = src.arrayOffset() + src.limit();
159
160            byte[] da = dst.array();
161            int dp = dst.arrayOffset() + dst.position();
162            int dl = dst.arrayOffset() + dst.limit();
163            int len  = Math.min(dl - dp, sl - sp);
164
165            while (len-- > 0) {
166                char c = sa[sp];
167                int b = encode(c);
168                if (b == UNMAPPABLE_ENCODING) {
169                    if (Character.isSurrogate(c)) {
170                        if (sgp == null)
171                            sgp = new Surrogate.Parser();
172                        if (sgp.parse(c, sa, sp, sl) < 0) {
173                            return withResult(sgp.error(), src, sp, dst, dp);
174                        }
175                        return withResult(sgp.unmappableResult(), src, sp, dst, dp);
176                    }
177                    return withResult(CoderResult.unmappableForLength(1),
178                               src, sp, dst, dp);
179                }
180                da[dp++] = (byte)b;
181                sp++;
182            }
183            return withResult(sp < sl ? CoderResult.OVERFLOW : CoderResult.UNDERFLOW,
184                              src, sp, dst, dp);
185        }
186
187        private CoderResult encodeBufferLoop(CharBuffer src, ByteBuffer dst) {
188            int mark = src.position();
189            try {
190                while (src.hasRemaining()) {
191                    char c = src.get();
192                    int b = encode(c);
193                    if (b == UNMAPPABLE_ENCODING) {
194                        if (Character.isSurrogate(c)) {
195                            if (sgp == null)
196                                sgp = new Surrogate.Parser();
197                            if (sgp.parse(c, src) < 0)
198                                return sgp.error();
199                            return sgp.unmappableResult();
200                        }
201                        return CoderResult.unmappableForLength(1);
202                    }
203                    if (!dst.hasRemaining())
204                        return CoderResult.OVERFLOW;
205                    dst.put((byte)b);
206                    mark++;
207                }
208                return CoderResult.UNDERFLOW;
209            } finally {
210                src.position(mark);
211            }
212        }
213
214        protected CoderResult encodeLoop(CharBuffer src, ByteBuffer dst) {
215            if (src.hasArray() && dst.hasArray())
216                return encodeArrayLoop(src, dst);
217            else
218                return encodeBufferLoop(src, dst);
219        }
220
221        public final int encode(char ch) {
222            char index = c2bIndex[ch >> 8];
223            if (index == UNMAPPABLE_ENCODING)
224                return UNMAPPABLE_ENCODING;
225            return c2b[index + (ch & 0xff)];
226        }
227
228        private byte repl = (byte)'?';
229        protected void implReplaceWith(byte[] newReplacement) {
230            repl = newReplacement[0];
231        }
232
233        public int encode(char[] src, int sp, int len, byte[] dst) {
234            int dp = 0;
235            int sl = sp + Math.min(len, dst.length);
236            while (sp < sl) {
237                char c = src[sp++];
238                int b = encode(c);
239                if (b != UNMAPPABLE_ENCODING) {
240                    dst[dp++] = (byte)b;
241                    continue;
242                }
243                if (Character.isHighSurrogate(c) && sp < sl &&
244                    Character.isLowSurrogate(src[sp])) {
245                    if (len > dst.length) {
246                        sl++;
247                        len--;
248                    }
249                    sp++;
250                }
251                dst[dp++] = repl;
252            }
253            return dp;
254        }
255    }
256
257    // init the c2b and c2bIndex tables from b2c.
258    public static void initC2B(char[] b2c, char[] c2bNR,
259                               char[] c2b, char[] c2bIndex) {
260        for (int i = 0; i < c2bIndex.length; i++)
261            c2bIndex[i] = UNMAPPABLE_ENCODING;
262        for (int i = 0; i < c2b.length; i++)
263            c2b[i] = UNMAPPABLE_ENCODING;
264        int off = 0;
265        for (int i = 0; i < b2c.length; i++) {
266            char c = b2c[i];
267            if (c == UNMAPPABLE_DECODING)
268                continue;
269            int index = (c >> 8);
270            if (c2bIndex[index] == UNMAPPABLE_ENCODING) {
271                c2bIndex[index] = (char)off;
272                off += 0x100;
273            }
274            index = c2bIndex[index] + (c & 0xff);
275            c2b[index] = (char)((i>=0x80)?(i-0x80):(i+0x80));
276        }
277        if (c2bNR != null) {
278            // c-->b nr entries
279            int i = 0;
280            while (i < c2bNR.length) {
281                char b = c2bNR[i++];
282                char c = c2bNR[i++];
283                int index = (c >> 8);
284                if (c2bIndex[index] == UNMAPPABLE_ENCODING) {
285                    c2bIndex[index] = (char)off;
286                    off += 0x100;
287                }
288                index = c2bIndex[index] + (c & 0xff);
289                c2b[index] = b;
290            }
291        }
292    }
293}
294