Initial Commit

org/globalgiving/session/BetterPersistentManager.java

@@ -0,0 +1,69 @@
+package org.globalgiving.session;
+
+import java.io.IOException;
+
+import org.apache.catalina.Session;
+import org.apache.catalina.session.PersistentManagerBase;
+import org.apache.catalina.session.StandardSession;
+
+/**
+ * Implementation of the <b>Manager</b> interface that makes use of a Store to swap active Sessions to disk. It can be
+ * configured to achieve several different goals:
+ * <ul>
+ * <li>Persist sessions across restarts of the Container</li>
+ * <li>Fault tolerance, keep sessions backed up on disk to allow recovery in the event of unplanned restarts.</li>
+ * <li>Limit the number of active sessions kept in memory by swapping less active sessions out to disk.</li>
+ * </ul>
+ * GlobalGiving Modifications:
+ * <ul>
+ * <li>Don't persist session when swapping if the backup time is less than the swap time (it is already persisted).</li>
+ * <li>Run backups before swapping.</li>
+ * </ul>
+ *
+ * @author Justin Rupp ([email protected])
+ */
+public final class BetterPersistentManager extends PersistentManagerBase
+{
+   /**
+    * The descriptive name of this Manager implementation (for logging).
+    */
+   private static final String name = "BetterPersistentManager";
+
+   /** {@inheritDoc} */
+   @Override
+   public String getName()
+   {
+      return name;
+   }
+
+   /** {@inheritDoc} */
+   @Override
+   public void processPersistenceChecks()
+   {
+      super.processMaxIdleBackups();
+      super.processMaxIdleSwaps();
+      super.processMaxActiveSwaps();
+   }
+
+   /**
+    * Remove the session from the Manager's list of active sessions and write it out out to the Store if it has not
+    * already been backed up. If the session is past expiration or invalid, this method does nothing.
+    */
+   @Override
+   protected void swapOut(Session session) throws IOException
+   {
+      if (super.store == null || !session.isValid())
+      {
+         return;
+      }
+
+      ((StandardSession) session).passivate();
+      // Only write the session if idle backup is disabled, or set to run at the same or greater interval as swapping.
+      if (super.getMaxIdleBackup() < 0 || super.getMaxIdleBackup() >= super.getMaxIdleSwap())
+      {
+         super.writeSession(session);
+      }
+      super.removeSuper(session);
+      session.recycle();
+   }
+}