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1
28
29 package com.caucho.server.host;
30
31 import com.caucho.log.Log;
32 import com.caucho.util.CharBuffer;
33 import com.caucho.util.L10N;
34
35 import java.util.logging.Level  ;
36 import java.util.logging.Logger ;
37
38
39
42 public class DomainName {
43 static final Logger log = Log.open(DomainName.class);
44 static final L10N L = new L10N(DomainName.class);
45
46 private final static char ENCODE[];
47 private final static int DECODE[];
48
49 private final static int base = 36;
50 private final static int tmin = 1;
51 private final static int tmax = 26;
52 private final static int skew = 38;
53 private final static int damp = 700;
54 private final static int initialBias = 72;
55 private final static int initialN = 128;
56
57
60 public static String fromAscii(String source)
61 {
62 CharBuffer result = CharBuffer.allocate();
63 CharBuffer cb = CharBuffer.allocate();
64
65 int index = 0;
66 int length = source.length();
67 boolean isFirst = true;
68
69 try {
70 while (index < length) {
71 char ch = source.charAt(index + 0);
72
73 if (isFirst && index + 4 < length &&
74 source.charAt(index + 0) == 'x' &&
75 source.charAt(index + 1) == 'n' &&
76 source.charAt(index + 2) == '-' &&
77 source.charAt(index + 3) == '-') {
78 int p = source.indexOf('.', index);
79 String seq;
80
81 if (p < 0)
82 seq = source.substring(index + 4);
83 else
84 seq = source.substring(index + 4, p);
85
86 decode(result, cb, seq);
87
88 index += 4 + seq.length();
89 continue;
90 }
91
92 index++;
93
94 isFirst = false;
95
96 if (ch == '.') {
97 isFirst = true;
98
99 result.append(ch);
100 }
101 else
102 result.append(Character.toLowerCase(ch));
103 }
104
105 return result.close();
106 } catch (Throwable e) {
107 log.log(Level.WARNING, e.toString(), e);
108
109 throw new RuntimeException (e);
110 }
111 }
112
113
116 public static String toAscii(String source)
117 {
118 CharBuffer result = CharBuffer.allocate();
119 CharBuffer cb = CharBuffer.allocate();
120
121 int head = 0;
122 int length = source.length();
123
124 while (head < length) {
125 boolean isAscii = true;
126
127 cb.clear();
128
129 int i = head;
130 for (; i < length; i++) {
131 char ch = source.charAt(i);
132
133 if (ch == '.') {
134 cb.append(ch);
135 break;
136 }
137 else if (ch <= 0x7f)
138 cb.append(ch);
139 else {
140 isAscii = false;
141 break;
142 }
143 }
144
145 if (isAscii) {
146 head = i + 1;
147 result.append(cb);
148 continue;
149 }
150
151 cb.clear();
152 i = head;
153 for (; i < length; i++) {
154 char ch = source.charAt(i);
155
156 if (ch == '.')
157 break;
158
159 cb.append(ch);
161 }
162 head = i;
163
164 String seq = cb.toString();
165
166 cb.clear();
167
168 toAscii(cb, seq);
169
170 result.append(cb);
171 }
172
173 return result.close();
174 }
175
176 private static void decode(CharBuffer result, CharBuffer cb, String seq)
177 {
178 int length = seq.length();
179 int b = 0;
180
181 for (int i = 0; i < length; i++) {
182 char ch = seq.charAt(i);
183
184 if (ch == '-')
185 b = i;
186 }
187
188 for (int i = 0; i < b; i++) {
189 char ch = seq.charAt(i);
190
191 cb.append(Character.toLowerCase(ch));
192 }
193
194 int in = b > 0 ? b + 1 : 0;
195 int i = 0;
196 int bias = initialBias;
197 int out = cb.length();
198 int n = initialN;
199
200 while (in < length) {
201 int oldi = i;
202 int w = 1;
203
204 for (int k = base; true; k += base) {
205 char ch = seq.charAt(in++);
206 int digit = DECODE[ch];
207
208 i += digit * w;
209
210 int t;
211 if (k <= bias)
212 t = tmin;
213 else if (bias + tmax <= k)
214 t = tmax;
215 else
216 t = k - bias;
217
218 if (digit < t)
219 break;
220
221 w *= (base - t);
222 }
223
224 bias = adapt(i - oldi, out + 1, oldi == 0);
225
226 n += i / (out + 1);
227 i %= (out + 1);
228
229 cb.append(' ');
230 char []cBuf = cb.getBuffer();
231
232 System.arraycopy(cBuf, i, cBuf, i + 1, out - i);
233 cBuf[i++] = Character.toLowerCase((char) n);
234
235 out++;
236 }
237
238 result.append(cb);
239 }
240
241 private static void toAscii(CharBuffer cb, String seq)
242 {
243 cb.append("xn--");
244
245 int length = seq.length();
246
247 int index = 0;
248 int n = initialN;
249 int delta = 0;
250 int bias = initialBias;
251 int b = 0;
253 for (int i = 0; i < length; i++) {
254 char ch = seq.charAt(i);
255 if (ch < 0x80) {
256 cb.append(ch);
257 b++;
258 }
259 }
260
261 if (b > 0)
262 cb.append('-');
263
264 int h = b;
265
266 while (h < length) {
267 int m = 0xffff;
268
269 for (int i = 0; i < length; i++) {
270 char ch = seq.charAt(i);
271
272 if (n <= ch && ch < m)
273 m = ch;
274 }
275
276 delta = delta + (m - n) * (h + 1);
278 n = m;
279
280 for (int i = 0; i < length; i++) {
281 int ch = seq.charAt(i);
282
283 if (ch < n) {
284 delta++;
285 }
286
287 if (ch == n) {
288 int q = delta;
289
290 for (int k = base; true; k += base) {
291 int t;
292
293 if (k <= bias)
294 t = tmin;
295 else if (bias + tmax <= k)
296 t = tmax;
297 else
298 t = k - bias;
299
300 if (q < t)
301 break;
302
303 cb.append(ENCODE[t + (q - t) % (base - t)]);
304 q = (q - t) / (base - t);
305 }
306
307 cb.append(ENCODE[q]);
308 bias = adapt(delta, h + 1, h == b);
309 delta = 0;
310 h++;
311 }
312 }
313
314 delta++;
315 n++;
316 }
317 }
318
319 private static int adapt(int delta, int nPoints, boolean isFirst)
320 {
321 int k;
322
323 delta = isFirst ? delta / damp : delta / 2;
324 delta += delta / nPoints;
325
326 for (k = 0; ((base - tmin) * tmax) / 2 < delta; k += base) {
327 delta /= base - tmin;
328 }
329
330 return k + (base - tmin + 1) * delta / (delta + skew);
331 }
332
333 static {
334 ENCODE = new char[36];
335
336 for (int i = 0; i < 26; i++) {
337 ENCODE[i] = (char) ('a' + i);
338 }
339
340 for (int i = 0; i < 10; i++) {
341 ENCODE[i + 26] = (char) ('0' + i);
342 }
343
344 DECODE = new int[0x80];
345
346 for (int i = 0; i < 26; i++) {
347 DECODE[(char) ('a' + i)] = i;
348 DECODE[(char) ('A' + i)] = i;
349 }
350
351 for (int i = 0; i < 10; i++) {
352 DECODE[(char) ('0' + i)] = 26 + i;
353 }
354 }
355 }
356 |
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