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1
4 package org.roller.presentation.pagecache.rollercache;
5 import org.apache.commons.logging.Log;
6 import org.apache.commons.logging.LogFactory;
7 import org.roller.pojos.UserData;
8 import org.roller.presentation.LanguageUtil;
9 import org.roller.presentation.pagecache.FilterHandler;
10 import org.roller.util.LRUCache;
11
12 import java.io.IOException  ;
13 import java.util.ArrayList ;
14 import java.util.Collections ;
15 import java.util.Iterator ;
16 import java.util.List ;
17 import java.util.Locale ;
18 import java.util.Map ;
19 import java.util.Set ;
20 import java.util.Timer ;
21 import java.util.TimerTask ;
22 import java.util.TreeMap ;
23
24 import javax.servlet.FilterChain ;
25 import javax.servlet.FilterConfig ;
26 import javax.servlet.ServletException ;
27 import javax.servlet.ServletRequest ;
28 import javax.servlet.ServletResponse ;
29 import javax.servlet.http.HttpServletRequest ;
30 import javax.servlet.http.HttpServletResponse ;
31 import org.roller.config.RollerConfig;
32
33
51 public class LRUCacheHandler implements FilterHandler
52 {
53 private static Log mLogger =
54 LogFactory.getFactory().getInstance(LRUCacheHandler.class);
55
56 private Map mPageCache = null;
57
58 private String mName = null;
59
60
61 private long mTimeoutInterval = 30 * 60 * 1000;
63
64 private float mTimeoutRatio = 1.0F;
65
66 private int misses = 0;
68 private int hits = 0;
69
70 private final static String FILE_SEPARATOR = "/";
71 private final static char FILE_SEPARATOR_CHAR = FILE_SEPARATOR.charAt(0);
72 private final static short AVERAGE_KEY_LENGTH = 30;
73 private static final String m_strBase64Chars =
74 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
75
76
77 public LRUCacheHandler(FilterConfig config)
78 {
79 mName = config.getFilterName();
80 mLogger.info("Initializing for: " + mName);
81
82 String cacheSize = RollerConfig.getProperty("cache.filter.page.size");
83 String cacheTimeout = RollerConfig.getProperty("cache.filter.page.timeout");
84
85 int size = 200;
86 try
87 {
88 size = Integer.parseInt(cacheSize);
89 }
90 catch (Exception e)
91 {
92 mLogger.warn(config.getFilterName()
93 + "Can't read cache size parameter, using default...");
94 }
95 mLogger.info(mName + " size=" + size);
96 mPageCache = Collections.synchronizedMap(new LRUCache(size));
97
98 long intervalSeconds = mTimeoutInterval / 1000L;
99 try
100 {
101 mTimeoutInterval = 1000L * Long.parseLong(cacheTimeout);
102
103 if (mTimeoutInterval == -1)
104 {
105 mLogger.info(config.getFilterName()
106 + "timeoutInterval of -1: timeouts are disabled");
107 }
108 else if (mTimeoutInterval < (30 * 1000))
109 {
110 mTimeoutInterval = 30 * 1000;
111 mLogger.warn(config.getFilterName()
112 + "timeoutInterval cannot be less than 30 seconds");
113 }
114 }
115 catch (Exception e)
116 {
117 mLogger.warn(config.getFilterName()
118 + "Can't read timeoutInterval parameter, disabling timeout.");
119 mTimeoutInterval = -1;
120 }
121 mLogger.info(mName + " timeoutInterval=" + intervalSeconds);
122
123 try
124 {
125 mTimeoutRatio = Float.parseFloat(
126 config.getInitParameter("timeoutRatio"));
127 }
128 catch (Exception e)
129 {
130 mLogger.warn(config.getFilterName()
131 + "Can't read timeoutRatio parameter, using default...");
132 }
133 mLogger.info(mName + " timeoutRatio=" + mTimeoutRatio);
134
135 if (mTimeoutInterval != -1 && mTimeoutRatio != 0.0)
136 {
137 Timer timer = new Timer ();
138 timer.scheduleAtFixedRate(new TimerTask () {
139 public void run() {
140 timeoutCache();
141 }
142 }, mTimeoutInterval, mTimeoutInterval);
143 }
144 }
145
146
149 public void destroy()
150 {
151 }
152
153
158 public void doFilter(ServletRequest req, ServletResponse res,
159 FilterChain chain) throws ServletException , IOException
160 {
161 HttpServletRequest request = (HttpServletRequest ) req;
162 HttpServletResponse response = (HttpServletResponse ) res;
163
164 Locale locale = LanguageUtil.getViewLocale(request);
166
167 String generatedKey = null;
169 if (locale != null)
170 {
171 generatedKey = generateEntryKey(null,
172 request, 1, locale.getLanguage());
173 }
174 else
175 {
176 generatedKey = generateEntryKey(null,
177 request, 1, null);
178 }
179
180 java.security.Principal prince = request.getUserPrincipal();
182 StringBuffer keyb = new StringBuffer ();
183 keyb.append(generatedKey);
184 if (prince != null)
185 {
186 keyb.append("_");
187 keyb.append(prince);
188 }
189 String key = keyb.toString();
190
191 ResponseContent respContent = (ResponseContent)getFromCache(key);
192 if (respContent == null)
193 {
194 try
195 {
196 CacheHttpServletResponseWrapper cacheResponse =
197 new CacheHttpServletResponseWrapper(response);
198 chain.doFilter(request, cacheResponse);
199
200 if (request.getAttribute("DisplayException") == null)
203 {
204 ResponseContent rc = cacheResponse.getContent();
205 putToCache(key, rc);
206 }
207 else
208 {
209 StringBuffer sb = new StringBuffer ();
210 sb.append("Display exception, cache, key=");
211 sb.append(key);
212 mLogger.error(sb.toString());
213 }
214 }
215 catch (java.net.SocketException se)
216 {
217 }
219 catch (Exception e)
220 {
221 StringBuffer sb = new StringBuffer ();
223 sb.append("Error rendering page, key=");
224 sb.append(key);
225 mLogger.error(sb.toString());
226 }
227 }
228 else
229 {
230 try
231 {
232 respContent.writeTo(response);
233 }
234 catch (java.net.SocketException se)
235 {
236 }
238 catch (Exception e)
239 {
240 if (mLogger.isDebugEnabled())
241 {
242 StringBuffer sb = new StringBuffer ();
243 sb.append("Probably a client abort exception, key=");
244 sb.append(key);
245 mLogger.error(sb.toString());
246 }
247 }
248
249 }
250 }
251
252
255 public synchronized void flushCache(HttpServletRequest req)
256 {
257 mPageCache.clear();
258 }
259
260
263 public synchronized void removeFromCache(HttpServletRequest req, UserData user)
264 {
265 String rssString = "/rss/" + user.getUserName(); String pageString = "/page/" + user.getUserName(); String mainRssString = "/rss_"; List purgeList = new ArrayList ();
270
271 Iterator keys = mPageCache.keySet().iterator();
272 while (keys.hasNext())
273 {
274 String key = (String ) keys.next();
275
276 if (key.indexOf(rssString)!=-1 || key.indexOf(pageString)!=-1 || key.indexOf(mainRssString)!=-1)
277 {
278 purgeList.add(key);
279 }
280 }
281
282 Iterator purgeIter = purgeList.iterator();
283 while (purgeIter.hasNext())
284 {
285 String key = (String ) purgeIter.next();
286 mPageCache.remove(key);
287 }
288
289 if (mLogger.isDebugEnabled())
290 {
291 StringBuffer sb = new StringBuffer ();
292 sb.append("Purged, count=");
293 sb.append(purgeList.size());
294 sb.append(", user=");
295 sb.append(user.getUserName());
296 mLogger.debug(sb.toString());
297 }
298 }
299
300 public synchronized void timeoutCache()
301 {
302 if (mTimeoutRatio == 1.0)
303 {
304 mLogger.debug("Timing out whole cache: " + mName);
305 mPageCache.clear();
306 }
307 else
308 {
309 int numToTimeout = (int)(mTimeoutRatio * mPageCache.size());
310 mLogger.debug(
311 "Timing out " + numToTimeout + " of " + mPageCache.size()
312 + " entries from cache: " + mName);
313 ArrayList allKeys = new ArrayList (mPageCache.keySet());
314 for (int i=numToTimeout; i>0; i--)
315 {
316 mPageCache.remove(allKeys.get(i));
317 }
318 }
319 }
320
321
325 public synchronized Object getFromCache(String key)
326 {
327 Object entry = mPageCache.get(key);
328
329 if (entry != null && mLogger.isDebugEnabled())
330 {
331 hits++;
332 }
333 return entry;
334 }
335
336 public synchronized void putToCache(String key, Object entry)
337 {
338 mPageCache.put(key, entry);
339 if (mLogger.isDebugEnabled())
340 {
341 misses++;
342
343 StringBuffer sb = new StringBuffer ();
344 sb.append("Missed, cache size=");
345 sb.append(mPageCache.size());
346 sb.append(", hits=");
347 sb.append(hits);
348 sb.append(", misses=");
349 sb.append(misses);
350 sb.append(", key=");
351 sb.append(key);
352 mLogger.debug(sb.toString());
353 }
354 }
355
356 public String generateEntryKey(String key,
357 HttpServletRequest request, int scope, String language)
358 {
359 StringBuffer cBuffer = new StringBuffer (AVERAGE_KEY_LENGTH);
360 if (language != null)
362 {
363 cBuffer.append(FILE_SEPARATOR).append(language);
364 }
365
366
368 if (key != null)
369 {
370 cBuffer.append(FILE_SEPARATOR).append(key);
371 }
372 else
373 {
374 String generatedKey = request.getRequestURI();
375 if (generatedKey.charAt(0) != FILE_SEPARATOR_CHAR)
376 {
377 cBuffer.append(FILE_SEPARATOR_CHAR);
378 }
379 cBuffer.append(generatedKey);
380 cBuffer.append("_").append(request.getMethod()).append("_");
381 generatedKey = getSortedQueryString(request);
382 if (generatedKey != null)
383 {
384 try
385 {
386 java.security.MessageDigest digest =
387 java.security.MessageDigest.getInstance("MD5");
388 byte[] b = digest.digest(generatedKey.getBytes());
389 cBuffer.append("_");
390 cBuffer.append(toBase64(b).replace('/', '_'));
392 }
393 catch (Exception e)
394 {
395 }
397 }
398 }
399 return cBuffer.toString();
400 }
401
402 protected String getSortedQueryString(HttpServletRequest request)
403 {
404 Map paramMap = request.getParameterMap();
405 if (paramMap.isEmpty())
406 {
407 return null;
408 }
409 Set paramSet = new TreeMap (paramMap).entrySet();
410 StringBuffer buf = new StringBuffer ();
411 boolean first = true;
412 for (Iterator it = paramSet.iterator(); it.hasNext();)
413 {
414 Map.Entry entry = (Map.Entry ) it.next();
415 String [] values = (String []) entry.getValue();
416 for (int i = 0; i < values.length; i++)
417 {
418 String key = (String ) entry.getKey();
419 if ((key.length() != 10) || !"jsessionid".equals(key))
420 {
421 if (first)
422 {
423 first = false;
424 }
425 else
426 {
427 buf.append('&');
428 }
429 buf.append(key).append('=').append(values[i]);
430 }
431 }
432 }
433 if (buf.length() == 0)
435 {
436 return null;
437 }
438 else
439 {
440 return buf.toString();
441 }
442 }
443
444
447 private static String toBase64(byte[] aValue)
448 {
449 int byte1;
450 int byte2;
451 int byte3;
452 int iByteLen = aValue.length;
453 StringBuffer tt = new StringBuffer ();
454 for (int i = 0; i < iByteLen; i += 3)
455 {
456 boolean bByte2 = (i + 1) < iByteLen;
457 boolean bByte3 = (i + 2) < iByteLen;
458 byte1 = aValue[i] & 0xFF;
459 byte2 = (bByte2) ? (aValue[i + 1] & 0xFF) : 0;
460 byte3 = (bByte3) ? (aValue[i + 2] & 0xFF) : 0;
461 tt.append(m_strBase64Chars.charAt(byte1 / 4));
462 tt.append(m_strBase64Chars.charAt((byte2 / 16)
463 + ((byte1 & 0x3) * 16)));
464 tt.append(((bByte2) ? m_strBase64Chars.charAt((byte3 / 64)
465 + ((byte2 & 0xF) * 4)) : '='));
466 tt.append(((bByte3) ? m_strBase64Chars.charAt(byte3 & 0x3F) : '='));
467 }
468 return tt.toString();
469 }
470 }
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