OF-668: Ensure Pubsub write cache is persisted during Openfire shutdown

- Improved exception handling during shutdown
- Refactored LinkedList / LinkedListNode to use generics
- Refactored PublishedItem to remove persistence-specific retry attribute
- Added RetryWrapper to improve pubsub item persistence

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@13651 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/openfire/XMPPServer.java

@@ -42,6 +42,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 
 import org.dom4j.Document;
 import org.dom4j.io.SAXReader;
+import org.eclipse.jetty.util.log.Log;
 import org.jivesoftware.database.DbConnectionManager;
 import org.jivesoftware.openfire.admin.AdminManager;
 import org.jivesoftware.openfire.audit.AuditManager;
@@ -361,6 +362,7 @@ public class XMPPServer {
         }
 
         if (isStandAlone()) {
+        	Log.info("Registering shutdown hook (standalone mode)");
             Runtime.getRuntime().addShutdownHook(new ShutdownHookThread());
         }
 
@@ -682,6 +684,7 @@ public class XMPPServer {
      * inside of another server.
      */
     public void stop() {
+    	Log.info("Initiating shutdown ...");
         // Only do a system exit if we're running standalone
         if (isStandAlone()) {
             // if we're in a wrapper, we have to tell the wrapper to shut us down
@@ -934,24 +937,42 @@ public class XMPPServer {
         ClusterManager.shutdown();
         // Notify server listeners that the server is about to be stopped
         for (XMPPServerListener listener : listeners) {
-            listener.serverStopping();
+        	try {
+        		listener.serverStopping();
+        	} catch (Exception ex) {
+        		Log.error("Exception during listener shutdown", ex);
+        	}
         }
         // If we don't have modules then the server has already been shutdown
         if (modules.isEmpty()) {
             return;
         }
+    	Log.info("Shutting down " + modules.size() + " modules ...");
         // Get all modules and stop and destroy them
         for (Module module : modules.values()) {
-            module.stop();
-            module.destroy();
+        	try {
+	            module.stop();
+	            module.destroy();
+        	} catch (Exception ex) {
+        		Log.error("Exception during module shutdown", ex);
+        	}
         }
         // Stop all plugins
+    	Log.info("Shutting down plugins ...");
         if (pluginManager != null) {
-            pluginManager.shutdown();
+        	try {
+        		pluginManager.shutdown();
+        	} catch (Exception ex) {
+        		Log.error("Exception during plugin shutdown", ex);
+        	}
         }
         modules.clear();
         // Stop the Db connection manager.
-        DbConnectionManager.destroyConnectionProvider();
+        try {	
+        	DbConnectionManager.destroyConnectionProvider();
+        } catch (Exception ex) {
+    		Log.error("Exception during DB shutdown", ex);
+        }
 
         // Shutdown the task engine.
         TaskEngine.getInstance().shutdown();

src/java/org/jivesoftware/openfire/pubsub/PublishedItem.java

@@ -101,10 +101,6 @@ public class PublishedItem implements Serializable {
      * XML representation of the payload (for serialization)
      */
     private String payloadXML;
-    /**
-     * Persistence retry counter
-     */
-    private volatile transient int retryCount = 0;
     
     /**
      * Creates a published item
@@ -292,14 +288,6 @@ public class PublishedItem implements Serializable {
     	return getItemKey(nodeId,id);
     }
 
-    /**
-     * Returns (and increments) the item persistence retry counter
-     * @return Number of attempts made to persist this item to the DB
-     */
-	public int getRetryCount() {
-		return retryCount++;
-	}
-
 	/**
      * Returns a string that uniquely identifies this published item
      * in the following format: <i>nodeId:itemId</i>

src/java/org/jivesoftware/util/LinkedList.java

@@ -27,20 +27,21 @@ package org.jivesoftware.util;
  * reference to the node that is to be deleted.<p>
  *
  * @author Jive Software
+ * @param <E>
  */
-public class LinkedList {
+public class LinkedList<E> {
 
     /**
      * The root of the list keeps a reference to both the first and last
      * elements of the list.
      */
-    private LinkedListNode head;
+    private LinkedListNode<E> head;
 
     /**
      * Creates a new linked list.
      */
     public LinkedList() {
-    	head = new LinkedListNode("head");
+    	head = new LinkedListNode<E>();
     }
 
     /**
@@ -48,8 +49,8 @@ public class LinkedList {
      *
      * @return the first element of the list.
      */
-    public LinkedListNode getFirst() {
-        LinkedListNode node = head.next;
+    public LinkedListNode<E> getFirst() {
+        LinkedListNode<E> node = head.next;
         if (node == head) {
             return null;
         }
@@ -61,8 +62,8 @@ public class LinkedList {
      *
      * @return the last element of the list.
      */
-    public LinkedListNode getLast() {
-        LinkedListNode node = head.previous;
+    public LinkedListNode<E> getLast() {
+        LinkedListNode<E> node = head.previous;
         if (node == head) {
             return null;
         }
@@ -74,7 +75,7 @@ public class LinkedList {
      *
      * @param node the node to add to the beginning of the list.
      */
-    public LinkedListNode addFirst(LinkedListNode node) {
+    public LinkedListNode<E> addFirst(LinkedListNode<E> node) {
     	return node.insert(head.next, head);
     }
 
@@ -85,8 +86,8 @@ public class LinkedList {
      * @param object the object to add to the beginning of the list.
      * @return the node created to wrap the object.
      */
-    public LinkedListNode addFirst(Object object) {
-        return new LinkedListNode(object, head.next, head);
+    public LinkedListNode<E> addFirst(E object) {
+        return new LinkedListNode<E>(object, head.next, head);
     }
 
     /**
@@ -94,7 +95,7 @@ public class LinkedList {
      *
      * @param node the node to add to the beginning of the list.
      */
-    public LinkedListNode addLast(LinkedListNode node) {
+    public LinkedListNode<E> addLast(LinkedListNode<E> node) {
     	return node.insert(head, head.previous);
     }
 
@@ -105,8 +106,8 @@ public class LinkedList {
      * @param object the object to add to the end of the list.
      * @return the node created to wrap the object.
      */
-    public LinkedListNode addLast(Object object) {
-        return new LinkedListNode(object, head, head.previous);
+    public LinkedListNode<E> addLast(E object) {
+        return new LinkedListNode<E>(object, head, head.previous);
     }
 
     /**
@@ -114,7 +115,7 @@ public class LinkedList {
      */
     public void clear() {
         //Remove all references in the list.
-        LinkedListNode node = getLast();
+        LinkedListNode<E> node = getLast();
         while (node != null) {
             node.remove();
             node = getLast();
@@ -132,7 +133,7 @@ public class LinkedList {
      */
     @Override
 	public String toString() {
-        LinkedListNode node = head.next;
+        LinkedListNode<E> node = head.next;
         StringBuilder buf = new StringBuilder();
         while (node != head) {
             buf.append(node.toString()).append(", ");

src/java/org/jivesoftware/util/LinkedListNode.java

@@ -38,11 +38,11 @@ package org.jivesoftware.util;
  * @author Jive Software
  * @see org.jivesoftware.util.LinkedList
  */
-public class LinkedListNode {
+public class LinkedListNode<E> {
 
-    public LinkedListNode previous;
-    public LinkedListNode next;
-    public Object object;
+    public LinkedListNode<E> previous;
+    public LinkedListNode<E> next;
+    public E object;
 
     /**
      * This class is further customized for the CoolServlets cache system. It
@@ -61,9 +61,8 @@ public class LinkedListNode {
      * Constructs an self-referencing node. This node acts as a start/end
      * sentinel when traversing nodes in a LinkedList.
      */
-    public LinkedListNode(Object object) {
+    public LinkedListNode() {
     	previous = next = this;
-    	this.object = object;
     }
 
     /**
@@ -73,7 +72,7 @@ public class LinkedListNode {
      * @param next     a reference to the next LinkedListNode in the list.
      * @param previous a reference to the previous LinkedListNode in the list.
      */
-    public LinkedListNode(Object object, LinkedListNode next, LinkedListNode previous) {
+    public LinkedListNode(E object, LinkedListNode<E> next, LinkedListNode<E> previous) {
     	if (next != null && previous != null) {
     		this.insert(next, previous);
     	}
@@ -84,7 +83,7 @@ public class LinkedListNode {
      * Removes this node from the linked list that it was a part of.
      * @return This node; next and previous references dropped
      */
-    public LinkedListNode remove() {
+    public LinkedListNode<E> remove() {
         previous.next = next;
         next.previous = previous;
         previous = next = null;
@@ -95,7 +94,7 @@ public class LinkedListNode {
      * Inserts this node into the linked list that it will be a part of.
      * @return This node, updated to reflect previous/next changes
      */
-    public LinkedListNode insert(LinkedListNode next, LinkedListNode previous) {
+    public LinkedListNode<E> insert(LinkedListNode<E> next, LinkedListNode<E> previous) {
         this.next = next;
         this.previous = previous;
         this.previous.next = this.next.previous = this;

src/java/org/jivesoftware/util/cache/DefaultCache.java

@@ -70,13 +70,13 @@ public class DefaultCache<K, V> implements Cache<K, V> {
      * Linked list to maintain order that cache objects are accessed
      * in, most used to least used.
      */
-    protected org.jivesoftware.util.LinkedList lastAccessedList;
+    protected org.jivesoftware.util.LinkedList<K> lastAccessedList;
 
     /**
      * Linked list to maintain time that cache objects were initially added
      * to the cache, most recently added to oldest added.
      */
-    protected org.jivesoftware.util.LinkedList ageList;
+    protected org.jivesoftware.util.LinkedList<K> ageList;
 
     /**
      * Maximum size in bytes that the cache can grow to.
@@ -127,8 +127,8 @@ public class DefaultCache<K, V> implements Cache<K, V> {
         // is too small in almost all cases, so we set it bigger.
         map = new HashMap<K, CacheObject<V>>(103);
 
-        lastAccessedList = new org.jivesoftware.util.LinkedList();
-        ageList = new org.jivesoftware.util.LinkedList();
+        lastAccessedList = new org.jivesoftware.util.LinkedList<K>();
+        ageList = new org.jivesoftware.util.LinkedList<K>();
     }
 
     public synchronized V put(K key, V value) {
@@ -153,12 +153,12 @@ public class DefaultCache<K, V> implements Cache<K, V> {
         DefaultCache.CacheObject<V> cacheObject = new DefaultCache.CacheObject<V>(value, objectSize);
         map.put(key, cacheObject);
         // Make an entry into the cache order list.
-        LinkedListNode lastAccessedNode = lastAccessedList.addFirst(key);
+        LinkedListNode<K> lastAccessedNode = lastAccessedList.addFirst(key);
         // Store the cache order list entry so that we can get back to it
         // during later lookups.
         cacheObject.lastAccessedListNode = lastAccessedNode;
         // Add the object to the age list
-        LinkedListNode ageNode = ageList.addFirst(key);
+        LinkedListNode<K> ageNode = ageList.addFirst(key);
         // We make an explicit call to currentTimeMillis() so that total accuracy
         // of lifetime calculations is better than one second.
         ageNode.timestamp = System.currentTimeMillis();
@@ -191,7 +191,7 @@ public class DefaultCache<K, V> implements Cache<K, V> {
         // Remove the object from it's current place in the cache order list,
         // and re-insert it at the front of the list.
         cacheObject.lastAccessedListNode.remove();
-        lastAccessedList.addFirst(cacheObject.lastAccessedListNode);
+        lastAccessedList.addFirst((LinkedListNode<K>) cacheObject.lastAccessedListNode);
 
         return cacheObject.object;
     }
@@ -224,9 +224,9 @@ public class DefaultCache<K, V> implements Cache<K, V> {
         // Now, reset all containers.
         map.clear();
         lastAccessedList.clear();
-        lastAccessedList = new org.jivesoftware.util.LinkedList();
+        lastAccessedList = new org.jivesoftware.util.LinkedList<K>();
         ageList.clear();
-        ageList = new org.jivesoftware.util.LinkedList();
+        ageList = new org.jivesoftware.util.LinkedList<K>();
 
         cacheSize = 0;
         cacheHits = 0;
@@ -558,7 +558,7 @@ public class DefaultCache<K, V> implements Cache<K, V> {
         // of the linked list until they are no longer too old. We get to avoid
         // any hash lookups or looking at any more objects than is strictly
         // neccessary.
-        LinkedListNode node = ageList.getLast();
+        LinkedListNode<K> node = ageList.getLast();
         // If there are no entries in the age list, return.
         if (node == null) {
             return;
@@ -639,14 +639,14 @@ public class DefaultCache<K, V> implements Cache<K, V> {
          * accessed, the node is removed from its current spot in the list and
          * moved to the front.
          */
-        public LinkedListNode lastAccessedListNode;
+        public LinkedListNode<?> lastAccessedListNode;
 
         /**
          * A reference to the node in the age order list. We keep the reference
          * here to avoid linear scans of the list. The reference is used if the
          * object has to be deleted from the list.
          */
-        public LinkedListNode ageListNode;
+        public LinkedListNode<?> ageListNode;
 
         /**
          * A count of the number of times the object has been read from cache.