1 | /* |
2 | * @(#) $Id: AbstractIoFilterChain.java 357871 2005-12-20 01:56:40Z trustin $ |
3 | * |
4 | * Copyright 2004 The Apache Software Foundation |
5 | * |
6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
7 | * you may not use this file except in compliance with the License. |
8 | * You may obtain a copy of the License at |
9 | * |
10 | * http://www.apache.org/licenses/LICENSE-2.0 |
11 | * |
12 | * Unless required by applicable law or agreed to in writing, software |
13 | * distributed under the License is distributed on an "AS IS" BASIS, |
14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
15 | * See the License for the specific language governing permissions and |
16 | * limitations under the License. |
17 | * |
18 | */ |
19 | package org.apache.mina.io; |
20 | |
21 | import java.util.ArrayList; |
22 | import java.util.HashMap; |
23 | import java.util.IdentityHashMap; |
24 | import java.util.Iterator; |
25 | import java.util.List; |
26 | import java.util.Map; |
27 | |
28 | import org.apache.mina.common.ByteBuffer; |
29 | import org.apache.mina.common.IdleStatus; |
30 | import org.apache.mina.io.IoFilter.NextFilter; |
31 | import org.apache.mina.util.SessionLog; |
32 | |
33 | /** |
34 | * An abstract implementation of {@link IoFilterChain} that provides |
35 | * common operations for developers to support specific transport types. |
36 | * <p> |
37 | * All methods has been implemented. The list of filters is maintained |
38 | * as a doublely linked list. You can fire any MINA events which is filtered |
39 | * by this chain using these public methods: |
40 | * <ul> |
41 | * <li></li> |
42 | * </ul> |
43 | * |
44 | * The only method a developer should implement is {@link #doWrite(IoSession, ByteBuffer, Object)}. |
45 | * This method is invoked when filter chain is evaluated for |
46 | * {@link IoFilter#filterWrite(NextFilter, IoSession, ByteBuffer, Object)} and |
47 | * finally to be written to the underlying transport layer (e.g. socket) |
48 | * |
49 | * @author The Apache Directory Project |
50 | * @version $Rev: 357871 $, $Date: 2005-12-20 10:56:40 +0900 (Tue, 20 Dec 2005) $ |
51 | */ |
52 | public abstract class AbstractIoFilterChain implements IoFilterChain |
53 | { |
54 | private final Map name2entry = new HashMap(); |
55 | |
56 | private final Map filter2entry = new IdentityHashMap(); |
57 | |
58 | private final Entry head; |
59 | |
60 | private final Entry tail; |
61 | |
62 | protected AbstractIoFilterChain() |
63 | { |
64 | head = new Entry( null, null, "head", createHeadFilter() ); |
65 | tail = new Entry( head, null, "tail", createTailFilter() ); |
66 | head.nextEntry = tail; |
67 | } |
68 | |
69 | /** |
70 | * Override this method to create custom head of this filter chain. |
71 | */ |
72 | protected IoFilter createHeadFilter() |
73 | { |
74 | return new IoFilter() |
75 | { |
76 | public void sessionOpened( NextFilter nextFilter, IoSession session ) throws Exception |
77 | { |
78 | nextFilter.sessionOpened( session ); |
79 | } |
80 | |
81 | public void sessionClosed( NextFilter nextFilter, IoSession session ) throws Exception |
82 | { |
83 | nextFilter.sessionClosed( session ); |
84 | } |
85 | |
86 | public void sessionIdle( NextFilter nextFilter, IoSession session, |
87 | IdleStatus status ) throws Exception |
88 | { |
89 | nextFilter.sessionIdle( session, status ); |
90 | } |
91 | |
92 | public void exceptionCaught( NextFilter nextFilter, |
93 | IoSession session, Throwable cause ) throws Exception |
94 | { |
95 | nextFilter.exceptionCaught( session, cause ); |
96 | } |
97 | |
98 | public void dataRead( NextFilter nextFilter, IoSession session, |
99 | ByteBuffer buf ) throws Exception |
100 | { |
101 | nextFilter.dataRead( session, buf ); |
102 | } |
103 | |
104 | public void dataWritten( NextFilter nextFilter, IoSession session, |
105 | Object marker ) throws Exception |
106 | { |
107 | nextFilter.dataWritten( session, marker ); |
108 | } |
109 | |
110 | public void filterWrite( NextFilter nextFilter, IoSession session, |
111 | ByteBuffer buf, Object marker ) throws Exception |
112 | { |
113 | doWrite( session, buf, marker ); |
114 | } |
115 | }; |
116 | } |
117 | |
118 | /** |
119 | * Override this method to create custom tail of this filter chain. |
120 | */ |
121 | protected IoFilter createTailFilter() |
122 | { |
123 | return new IoFilter() |
124 | { |
125 | public void sessionOpened( NextFilter nextFilter, IoSession session ) throws Exception |
126 | { |
127 | session.getHandler().sessionOpened( session ); |
128 | } |
129 | |
130 | public void sessionClosed( NextFilter nextFilter, IoSession session ) throws Exception |
131 | { |
132 | session.getHandler().sessionClosed( session ); |
133 | } |
134 | |
135 | public void sessionIdle( NextFilter nextFilter, IoSession session, |
136 | IdleStatus status ) throws Exception |
137 | { |
138 | session.getHandler().sessionIdle( session, status ); |
139 | } |
140 | |
141 | public void exceptionCaught( NextFilter nextFilter, |
142 | IoSession session, Throwable cause ) throws Exception |
143 | { |
144 | session.getHandler().exceptionCaught( session, cause ); |
145 | } |
146 | |
147 | public void dataRead( NextFilter nextFilter, IoSession session, |
148 | ByteBuffer buf ) throws Exception |
149 | { |
150 | IoHandler handler = session.getHandler(); |
151 | try |
152 | { |
153 | handler.dataRead( session, buf ); |
154 | } |
155 | finally |
156 | { |
157 | buf.release(); |
158 | } |
159 | } |
160 | |
161 | public void dataWritten( NextFilter nextFilter, IoSession session, |
162 | Object marker ) throws Exception |
163 | { |
164 | session.getHandler().dataWritten( session, marker ); |
165 | } |
166 | |
167 | public void filterWrite( NextFilter nextFilter, |
168 | IoSession session, ByteBuffer buf, Object marker ) throws Exception |
169 | { |
170 | nextFilter.filterWrite( session, buf, marker ); |
171 | } |
172 | }; |
173 | } |
174 | |
175 | public IoFilter getChild( String name ) |
176 | { |
177 | Entry e = ( Entry ) name2entry.get( name ); |
178 | if ( e == null ) |
179 | { |
180 | return null; |
181 | } |
182 | return e.filter; |
183 | } |
184 | |
185 | /** |
186 | * Adds the specified interceptor with the specified name at the beginning of this chain. |
187 | */ |
188 | public synchronized void addFirst( String name, |
189 | IoFilter filter ) |
190 | { |
191 | checkAddable( name ); |
192 | register( head, name, filter ); |
193 | } |
194 | |
195 | |
196 | /** |
197 | * Adds the specified interceptor with the specified name at the end of this chain. |
198 | */ |
199 | public synchronized void addLast( String name, |
200 | IoFilter filter ) |
201 | { |
202 | checkAddable( name ); |
203 | register( tail.prevEntry, name, filter ); |
204 | } |
205 | |
206 | |
207 | /** |
208 | * Adds the specified interceptor with the specified name just before the interceptor whose name is |
209 | * <code>baseName</code> in this chain. |
210 | */ |
211 | public synchronized void addBefore( String baseName, |
212 | String name, |
213 | IoFilter filter ) |
214 | { |
215 | Entry baseEntry = checkOldName( baseName ); |
216 | checkAddable( name ); |
217 | register( baseEntry.prevEntry, name, filter ); |
218 | } |
219 | |
220 | |
221 | /** |
222 | * Adds the specified interceptor with the specified name just after the interceptor whose name is |
223 | * <code>baseName</code> in this chain. |
224 | */ |
225 | public synchronized void addAfter( String baseName, |
226 | String name, |
227 | IoFilter filter ) |
228 | { |
229 | Entry baseEntry = checkOldName( baseName ); |
230 | checkAddable( name ); |
231 | register( baseEntry, name, filter ); |
232 | } |
233 | |
234 | |
235 | /** |
236 | * Removes the interceptor with the specified name from this chain. |
237 | */ |
238 | public synchronized IoFilter remove( String name ) |
239 | { |
240 | Entry entry = checkOldName( name ); |
241 | Entry prevEntry = entry.prevEntry; |
242 | Entry nextEntry = entry.nextEntry; |
243 | prevEntry.nextEntry = nextEntry; |
244 | nextEntry.prevEntry = prevEntry; |
245 | |
246 | name2entry.remove( name ); |
247 | IoFilter filter = entry.filter; |
248 | filter2entry.remove( filter ); |
249 | |
250 | return filter; |
251 | } |
252 | |
253 | |
254 | /** |
255 | * Removes all interceptors added to this chain. |
256 | */ |
257 | public synchronized void clear() |
258 | { |
259 | Iterator it = new ArrayList( name2entry.keySet() ).iterator(); |
260 | while ( it.hasNext() ) |
261 | { |
262 | this.remove( ( String ) it.next() ); |
263 | } |
264 | } |
265 | |
266 | private void register( Entry prevEntry, String name, IoFilter filter ) |
267 | { |
268 | Entry newEntry = new Entry( prevEntry, prevEntry.nextEntry, name, filter ); |
269 | prevEntry.nextEntry.prevEntry = newEntry; |
270 | prevEntry.nextEntry = newEntry; |
271 | name2entry.put( name, newEntry ); |
272 | filter2entry.put( filter, newEntry ); |
273 | } |
274 | |
275 | /** |
276 | * Throws an exception when the specified interceptor name is not registered in this chain. |
277 | * |
278 | * @return An interceptor entry with the specified name. |
279 | */ |
280 | private Entry checkOldName( String baseName ) |
281 | { |
282 | Entry e = ( Entry ) name2entry.get( baseName ); |
283 | if ( e == null ) |
284 | { |
285 | throw new IllegalArgumentException( "Unknown interceptor name:" + |
286 | baseName ); |
287 | } |
288 | return e; |
289 | } |
290 | |
291 | |
292 | /** |
293 | * Checks the specified interceptor name is already taken and throws an exception if already taken. |
294 | */ |
295 | private void checkAddable( String name ) |
296 | { |
297 | if ( name2entry.containsKey( name ) ) |
298 | { |
299 | throw new IllegalArgumentException( "Other interceptor is using name '" + name + "'" ); |
300 | } |
301 | } |
302 | |
303 | public void sessionOpened( IoSession session ) |
304 | { |
305 | Entry head = this.head; |
306 | callNextSessionOpened(head, session); |
307 | } |
308 | |
309 | private void callNextSessionOpened( Entry entry, |
310 | IoSession session) |
311 | { |
312 | try |
313 | { |
314 | entry.filter.sessionOpened( entry.nextFilter, session ); |
315 | } |
316 | catch( Throwable e ) |
317 | { |
318 | exceptionCaught( session, e ); |
319 | } |
320 | } |
321 | |
322 | public void sessionClosed( IoSession session ) |
323 | { |
324 | Entry head = this.head; |
325 | callNextSessionClosed(head, session); |
326 | } |
327 | |
328 | private void callNextSessionClosed( Entry entry, |
329 | IoSession session ) |
330 | { |
331 | try |
332 | { |
333 | entry.filter.sessionClosed( entry.nextFilter, session ); |
334 | } |
335 | catch( Throwable e ) |
336 | { |
337 | exceptionCaught( session, e ); |
338 | } |
339 | } |
340 | |
341 | public void sessionIdle( IoSession session, IdleStatus status ) |
342 | { |
343 | Entry head = this.head; |
344 | callNextSessionIdle(head, session, status); |
345 | } |
346 | |
347 | private void callNextSessionIdle( Entry entry, |
348 | IoSession session, |
349 | IdleStatus status ) |
350 | { |
351 | try |
352 | { |
353 | entry.filter.sessionIdle( entry.nextFilter, session, status ); |
354 | } |
355 | catch( Throwable e ) |
356 | { |
357 | exceptionCaught( session, e ); |
358 | } |
359 | } |
360 | |
361 | public void dataRead( IoSession session, ByteBuffer buf ) |
362 | { |
363 | Entry head = this.head; |
364 | callNextDataRead(head, session, buf); |
365 | } |
366 | |
367 | private void callNextDataRead( Entry entry, |
368 | IoSession session, |
369 | ByteBuffer buf ) |
370 | { |
371 | try |
372 | { |
373 | entry.filter.dataRead( entry.nextFilter, session, buf ); |
374 | } |
375 | catch( Throwable e ) |
376 | { |
377 | exceptionCaught( session, e ); |
378 | } |
379 | } |
380 | |
381 | public void dataWritten( IoSession session, Object marker ) |
382 | { |
383 | Entry head = this.head; |
384 | callNextDataWritten(head, session, marker); |
385 | } |
386 | |
387 | private void callNextDataWritten( Entry entry, |
388 | IoSession session, |
389 | Object marker ) |
390 | { |
391 | try |
392 | { |
393 | entry.filter.dataWritten( entry.nextFilter, session, marker ); |
394 | } |
395 | catch( Throwable e ) |
396 | { |
397 | exceptionCaught( session, e ); |
398 | } |
399 | } |
400 | |
401 | public void exceptionCaught( IoSession session, Throwable cause ) |
402 | { |
403 | Entry head = this.head; |
404 | callNextExceptionCaught(head, session, cause); |
405 | } |
406 | |
407 | private void callNextExceptionCaught( Entry entry, |
408 | IoSession session, |
409 | Throwable cause ) |
410 | { |
411 | try |
412 | { |
413 | entry.filter.exceptionCaught( entry.nextFilter, session, cause ); |
414 | } |
415 | catch( Throwable e ) |
416 | { |
417 | SessionLog.warn( |
418 | session, |
419 | "Unexpected exception from exceptionCaught handler.", e ); |
420 | } |
421 | } |
422 | |
423 | public void filterWrite( IoSession session, ByteBuffer buf, Object marker ) |
424 | { |
425 | Entry tail = this.tail; |
426 | callPreviousFilterWrite( tail, session, buf, marker ); |
427 | } |
428 | |
429 | private void callPreviousFilterWrite( Entry entry, |
430 | IoSession session, |
431 | ByteBuffer buf, Object marker ) |
432 | { |
433 | if( buf == null ) |
434 | { |
435 | return; |
436 | } |
437 | |
438 | try |
439 | { |
440 | entry.filter.filterWrite( entry.nextFilter, session, buf, marker ); |
441 | } |
442 | catch( Throwable e ) |
443 | { |
444 | exceptionCaught( session, e ); |
445 | } |
446 | } |
447 | |
448 | public List getChildren() |
449 | { |
450 | List list = new ArrayList(); |
451 | Entry e = head.nextEntry; |
452 | while( e != tail ) |
453 | { |
454 | list.add( e.filter ); |
455 | e = e.nextEntry; |
456 | } |
457 | |
458 | return list; |
459 | } |
460 | |
461 | public List getChildrenReversed() |
462 | { |
463 | List list = new ArrayList(); |
464 | Entry e = tail.prevEntry; |
465 | while( e != head ) |
466 | { |
467 | list.add( e.filter ); |
468 | e = e.prevEntry; |
469 | } |
470 | return list; |
471 | } |
472 | |
473 | protected abstract void doWrite( IoSession session, ByteBuffer buffer, Object marker ); |
474 | |
475 | private class Entry |
476 | { |
477 | private Entry prevEntry; |
478 | |
479 | private Entry nextEntry; |
480 | |
481 | private final String name; |
482 | |
483 | private final IoFilter filter; |
484 | |
485 | private final NextFilter nextFilter; |
486 | |
487 | private Entry( Entry prevEntry, Entry nextEntry, |
488 | String name, IoFilter filter ) |
489 | { |
490 | if( filter == null ) |
491 | { |
492 | throw new NullPointerException( "filter" ); |
493 | } |
494 | if( name == null ) |
495 | { |
496 | throw new NullPointerException( "name" ); |
497 | } |
498 | |
499 | this.prevEntry = prevEntry; |
500 | this.nextEntry = nextEntry; |
501 | this.name = name; |
502 | this.filter = filter; |
503 | this.nextFilter = new NextFilter() |
504 | { |
505 | |
506 | public void sessionOpened( IoSession session ) |
507 | { |
508 | Entry nextEntry = Entry.this.nextEntry; |
509 | callNextSessionOpened( nextEntry, session ); |
510 | } |
511 | |
512 | public void sessionClosed( IoSession session ) |
513 | { |
514 | Entry nextEntry = Entry.this.nextEntry; |
515 | callNextSessionClosed( nextEntry, session ); |
516 | } |
517 | |
518 | public void sessionIdle( IoSession session, IdleStatus status ) |
519 | { |
520 | Entry nextEntry = Entry.this.nextEntry; |
521 | callNextSessionIdle( nextEntry, session, status ); |
522 | } |
523 | |
524 | public void exceptionCaught( IoSession session, |
525 | Throwable cause ) |
526 | { |
527 | Entry nextEntry = Entry.this.nextEntry; |
528 | callNextExceptionCaught( nextEntry, session, cause ); |
529 | } |
530 | |
531 | public void dataRead( IoSession session, ByteBuffer buf ) |
532 | { |
533 | Entry nextEntry = Entry.this.nextEntry; |
534 | callNextDataRead( nextEntry, session, buf ); |
535 | } |
536 | |
537 | public void dataWritten( IoSession session, Object marker ) |
538 | { |
539 | Entry nextEntry = Entry.this.nextEntry; |
540 | callNextDataWritten( nextEntry, session, marker ); |
541 | } |
542 | |
543 | public void filterWrite( IoSession session, ByteBuffer buf, Object marker ) |
544 | { |
545 | Entry nextEntry = Entry.this.prevEntry; |
546 | callPreviousFilterWrite( nextEntry, session, buf, marker ); |
547 | } |
548 | }; |
549 | } |
550 | |
551 | public String getName() |
552 | { |
553 | return name; |
554 | } |
555 | |
556 | public IoFilter getFilter() |
557 | { |
558 | return filter; |
559 | } |
560 | } |
561 | } |