Author: agilliland
Date: Tue Jan 17 22:50:27 2006
New Revision: 370070
URL: http://svn.apache.org/viewcvs?rev=370070&view=rev
Log:
last-modified-since checking for weblog pages.
Added:
incubator/roller/trunk/src/org/roller/presentation/filters/IfModifiedWeblogPageCacheFilter.java
Added:
incubator/roller/trunk/src/org/roller/presentation/filters/IfModifiedWeblogPageCacheFilter.java
URL:
http://svn.apache.org/viewcvs/incubator/roller/trunk/src/org/roller/presentation/filters/IfModifiedWeblogPageCacheFilter.java?rev=370070&view=auto
==============================================================================
---
incubator/roller/trunk/src/org/roller/presentation/filters/IfModifiedWeblogPageCacheFilter.java
(added)
+++
incubator/roller/trunk/src/org/roller/presentation/filters/IfModifiedWeblogPageCacheFilter.java
Tue Jan 17 22:50:27 2006
@@ -0,0 +1,372 @@
+/*
+ * IfModifiedWeblogPageCacheFilter.java
+ *
+ * Created on November 9, 2005, 9:02 PM
+ */
+
+package org.roller.presentation.filters;
+
+import java.io.IOException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Map;
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.roller.config.RollerConfig;
+import org.roller.pojos.BookmarkData;
+import org.roller.pojos.CommentData;
+import org.roller.pojos.FolderData;
+import org.roller.pojos.RefererData;
+import org.roller.pojos.UserData;
+import org.roller.pojos.WeblogCategoryData;
+import org.roller.pojos.WeblogEntryData;
+import org.roller.pojos.WeblogTemplate;
+import org.roller.pojos.WebsiteData;
+import org.roller.presentation.WeblogPageRequest;
+import org.roller.presentation.cache.Cache;
+import org.roller.presentation.cache.CacheHandler;
+import org.roller.presentation.cache.CacheManager;
+import org.roller.presentation.cache.LazyExpiringCacheEntry;
+
+
+/**
+ * A filter used for caching last modified dates.
+ *
+ * @web.filter name="IfModifiedWeblogPageCacheFilter"
+ *
+ * @author Allen Gilliland
+ */
+public class IfModifiedWeblogPageCacheFilter implements Filter, CacheHandler {
+
+ private static Log mLogger =
+ LogFactory.getLog(IfModifiedWeblogPageCacheFilter.class);
+
+ // a unique identifier for this cache, this is used as the prefix for
+ // roller config properties that apply to this cache
+ private static final String CACHE_ID = "cache.ifmodified.page";
+
+ private Cache mCache = null;
+
+ SimpleDateFormat dateFormatter =
+ new SimpleDateFormat("EEE MMM d HH:mm:ss z yyyy");
+
+
+ /**
+ * Process filter.
+ */
+ public void doFilter(ServletRequest req,
+ ServletResponse res,
+ FilterChain chain)
+ throws IOException, ServletException {
+
+ mLogger.debug("entering");
+
+ HttpServletRequest request = (HttpServletRequest) req;
+ HttpServletResponse response = (HttpServletResponse) res;
+
+ WeblogPageRequest pageRequest = null;
+ try {
+ pageRequest = new WeblogPageRequest(request);
+ } catch(Exception e) {
+ mLogger.error("error creating page request", e);
+ response.sendError(HttpServletResponse.SC_NOT_FOUND);
+ return;
+ }
+
+ String key = this.CACHE_ID+":"+this.generateKey(pageRequest);
+
+ Date updateTime = null;
+ try {
+ // we need the last expiration time for the given weblog
+ long lastExpiration = 0;
+ Date lastExpirationDate =
+ (Date)
CacheManager.getLastExpiredDate(pageRequest.getWeblogHandle());
+ if(lastExpirationDate != null)
+ lastExpiration = lastExpirationDate.getTime();
+
+ LazyExpiringCacheEntry entry =
+ (LazyExpiringCacheEntry) this.mCache.get(key);
+ if(entry != null) {
+ updateTime = (Date) entry.getValue(lastExpiration);
+
+ if(updateTime == null)
+ mLogger.debug("HIT-INVALID "+key);
+ }
+
+ if (updateTime == null) {
+ mLogger.debug("MISS "+key);
+
+ if(pageRequest.getWeblogHandle() != null) {
+ // just set updateTime to now
+ updateTime = new Date();
+ this.mCache.put(key, new
LazyExpiringCacheEntry(updateTime));
+ }
+
+ } else {
+ mLogger.debug("HIT "+key);
+ }
+
+ // Check the incoming if-modified-since header
+ Date sinceDate =
+ new Date(request.getDateHeader("If-Modified-Since"));
+
+ if (updateTime != null) {
+ // convert date (JDK 1.5 workaround)
+ String date = dateFormatter.format(updateTime);
+ updateTime = new Date(date);
+ if (updateTime.compareTo(sinceDate) <= 0) {
+ mLogger.debug("NOT_MODIFIED "+key);
+ response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
+ return;
+ }
+ }
+
+ } catch (IllegalArgumentException e) {
+ // Thrown by getDateHeader if not in valid format. This can be
+ // safely ignored, the only consequence is that the NOT MODIFIED
+ // response is not set.
+ }
+
+ // Set outgoing last modified header
+ if (updateTime != null) {
+ response.setDateHeader("Last-Modified", updateTime.getTime());
+ }
+
+ chain.doFilter(request, response);
+
+ mLogger.debug("exiting");
+ }
+
+
+ /**
+ * Generate a cache key from a parsed weblog page request.
+ * This generates a key of the form ...
+ *
+ * weblog/<handle>/page/<weblogPage>/[anchor]/<language>/[user]
+ * or
+ * weblog/<handle>/page/<weblogPage>/[date]/[category]/<language>/[user]
+ *
+ *
+ * examples ...
+ *
+ * weblog/foo/page/Weblog/en
+ * weblog/foo/page/Weblog/entry_anchor/en
+ * weblog/foo/page/Weblog/20051110/en
+ * weblog/foo/page/Weblog/MyCategory/en
+ *
+ */
+ private String generateKey(WeblogPageRequest pageRequest) {
+
+ StringBuffer key = new StringBuffer();
+ key.append("weblog/");
+ key.append(pageRequest.getWeblogHandle());
+ key.append("/page/");
+ key.append(pageRequest.getWeblogPage());
+
+ if(pageRequest.getWeblogAnchor() != null) {
+ // TODO: do we need to convert to base64 here?
+ // this.weblogAnchor =
Utilities.toBase64(this.weblogAnchor.getBytes());
+ key.append("/").append(pageRequest.getWeblogAnchor());
+ } else {
+ if(pageRequest.getWeblogDate() != null) {
+ key.append("/").append(pageRequest.getWeblogDate());
+ }
+
+ if(pageRequest.getWeblogCategory() != null) {
+ String cat = pageRequest.getWeblogCategory();
+ if(cat.startsWith("/")) {
+ cat = cat.substring(1);
+ }
+
+ key.append("/").append(cat);
+ }
+ }
+
+ // add language
+ key.append("/").append(pageRequest.getLanguage());
+
+ // add login state
+ if(pageRequest.getAuthenticUser() != null) {
+ key.append("/user=").append(pageRequest.getAuthenticUser());
+ }
+
+ return key.toString();
+ }
+
+
+ /**
+ * A weblog entry has changed.
+ */
+ public void invalidate(WeblogEntryData entry) {
+
+ mLogger.debug("invalidating entry = "+entry.getAnchor());
+
+ // we need to remove the following cached items if they exist
+ // - the weblog main page
+ // - the weblog entry permalink page
+ // - the weblog entry category page
+ // - the weblog entry date archive pages
+
+ /*
+ Set removeSet = new HashSet();
+
+ // TODO: it would be nice to be able to do this without iterating
+ // over the entire cache key set
+ String key = null;
+ Iterator allKeys = this.mCache.keySet().iterator();
+ while(allKeys.hasNext()) {
+ key = (String) allKeys.next();
+ if(key.startsWith("ifmod:weblog/"+entry.getWebsite().getHandle()))
{
+ removeSet.add(key);
+ }
+ }
+
+ this.mCache.remove(removeSet);
+ */
+ }
+
+
+ /**
+ * A weblog has changed.
+ */
+ public void invalidate(WebsiteData website) {
+
+ mLogger.debug("invalidating website = "+website.getHandle());
+
+ // we need to remove the following cached items if they exist
+ // - all pages for this weblog
+
+ /*
+ Set removeSet = new HashSet();
+
+ // TODO: it would be nice to be able to do this without iterating
+ // over the entire cache key set
+ String key = null;
+ Iterator allKeys = this.mCache.keySet().iterator();
+ while(allKeys.hasNext()) {
+ key = (String) allKeys.next();
+
+ if(key.startsWith("ifmod:weblog/"+website.getHandle())) {
+ removeSet.add(key);
+ }
+ }
+
+ this.mCache.remove(removeSet);
+ */
+ }
+
+
+ /**
+ * A bookmark has changed.
+ */
+ public void invalidate(BookmarkData bookmark) {
+ this.invalidate(bookmark.getWebsite());
+ }
+
+
+ /**
+ * A folder has changed.
+ */
+ public void invalidate(FolderData folder) {
+ this.invalidate(folder.getWebsite());
+ }
+
+
+ /**
+ * A comment has changed.
+ */
+ public void invalidate(CommentData comment) {
+ this.invalidate(comment.getWeblogEntry());
+ }
+
+
+ /**
+ * A referer has changed.
+ */
+ public void invalidate(RefererData referer) {
+ // ignored
+ // TODO: we probably should invalidate the entire website?
+ }
+
+
+ /**
+ * A user profile has changed.
+ */
+ public void invalidate(UserData user) {
+ // ignored
+ // TODO: i don't think weblog pages currently have user info, but this
may change
+ }
+
+
+ /**
+ * A category has changed.
+ */
+ public void invalidate(WeblogCategoryData category) {
+ this.invalidate(category.getWebsite());
+ }
+
+
+ /**
+ * A weblog template has changed.
+ */
+ public void invalidate(WeblogTemplate template) {
+ this.invalidate(template.getWebsite());
+ }
+
+
+ public void clear() {
+ this.mCache.clear();
+ }
+
+
+ public Map getStats() {
+
+ Map stats = new HashMap();
+
+ return stats;
+ }
+
+
+ /**
+ * Destroy method for this filter
+ */
+ public void destroy() {
+ }
+
+
+ /**
+ * Init method for this filter
+ */
+ public void init(FilterConfig filterConfig) {
+
+ mLogger.info("Initializing if-modified cache");
+
+ Map cacheProps = new HashMap();
+ Enumeration allProps = RollerConfig.keys();
+ String prop = null;
+ while(allProps.hasMoreElements()) {
+ prop = (String) allProps.nextElement();
+
+ // we are only interested in props for this cache
+ if(prop.startsWith(CACHE_ID+".")) {
+ cacheProps.put(prop.substring(CACHE_ID.length()+1),
+ RollerConfig.getProperty(prop));
+ }
+ }
+
+ mLogger.info(cacheProps);
+
+ mCache = CacheManager.constructCache(this, cacheProps);
+ }
+
+}
