new interface method ObjectCache.getStatistics

the statistics of a cache instance for an application can be retrieved
by calling `app.__app__.getCacheStatistics()`. That's not very useful for the 
default `ObjectCache` but essential for looking into what more complex cache
impls like `SwarmCache` do

we could remove all the other cache statistics methods like `getCacheUsage` 
and output that info in the map returned by `getCacheStatistics()`

i had to bump java to 1.5 for the generics.. if that's a problem we can
remove the generics

build.xml

@@ -102,8 +102,8 @@
         <replace file="${build.work}/src/helma/main/Server.java"
             token="__builddate__" value="${TODAY}"/>
         <javac srcdir="${build.work}/src"
-            source="1.4"
+            source="1.5"
-            target="1.4"
+            target="1.5"
             destdir="${build.classes}"
             debug="${debug}"
             deprecation="${deprecation}"

src/helma/framework/core/Application.java

@@ -37,7 +37,7 @@ import java.util.ArrayList;
 
 
 /**
- * The central class of a Helma application. This class keeps a pool of 
+ * The central class of a Helma application. This class keeps a pool of
  * request evaluators (threads with JavaScript interpreters), waits for
  * requests from the Web server or XML-RPC port and dispatches them to
  * the evaluators.
@@ -227,7 +227,7 @@ public final class Application implements Runnable {
         }
 
         this.name = name;
-        
+
         this.caseInsensitive = "true".equalsIgnoreCase(server.getAppsProperties(name).getProperty("caseInsensitive"));
 
         this.repositories = new ArrayList();
@@ -456,7 +456,7 @@ public final class Application implements Runnable {
                     releaseEvaluator(ev);
                 }
             }
-            
+
             // preallocate minThreads request evaluators
             int minThreads = 0;
 
@@ -834,6 +834,13 @@ public final class Application implements Runnable {
         return nmgr.countCacheEntries();
     }
 
+    /**
+     * Returns a map of cache statistics
+     */
+    public Map getCacheStatistics() {
+        return nmgr.getCacheStatistics();
+    }
+
     /**
      *  Set the application's root element to an arbitrary object. After this is called
      *  with a non-null object, the helma node manager will be bypassed. This function
@@ -1389,7 +1396,7 @@ public final class Application implements Runnable {
         }
         return null;
     }
-    
+
     /**
      * Returns the correct property name which is either case sensitive or case insensitive
      * @param propName the raw property name

src/helma/objectmodel/ObjectCache.java

@@ -110,4 +110,8 @@ public interface ObjectCache {
      */
     Object[] getCachedObjects();
 
+    /**
+     * Returns a map of statistics about the cache
+     */
+    java.util.Map<String,Object> getStatistics();
 }

src/helma/objectmodel/db/NodeManager.java

@@ -56,7 +56,7 @@ public final class NodeManager {
     }
 
     /**
-     * Initialize the NodeManager for the given dbHome and 
+     * Initialize the NodeManager for the given dbHome and
      * application properties. An embedded database will be
      * created in dbHome if one doesn't already exist.
      */
@@ -112,7 +112,7 @@ public final class NodeManager {
     }
 
     /**
-     *  Shut down this node manager. This is called when the application 
+     *  Shut down this node manager. This is called when the application
      *  using this node manager is stopped.
      */
     public void shutdown() throws DatabaseException {
@@ -295,7 +295,7 @@ public final class NodeManager {
                 synchronized (cache) {
                     Node old = (Node) cache.put(node.getKey(), node);
 
-                    if (old != node && old != null && !old.isNullNode() && 
+                    if (old != node && old != null && !old.isNullNode() &&
                             old.getState() != Node.INVALID) {
                         cache.put(node.getKey(), old);
                         cache.put(key, old);
@@ -432,14 +432,14 @@ public final class NodeManager {
     /**
      *  Insert a node into a different (relational) database than its default one.
      */
-    public void exportNode(Node node, DbSource dbs) 
+    public void exportNode(Node node, DbSource dbs)
                     throws SQLException, ClassNotFoundException {
         if (node == null) {
             throw new IllegalArgumentException("Node can't be null in exportNode");
         }
-        
+
         DbMapping dbm = node.getDbMapping();
-        
+
         if (dbs == null) {
             throw new IllegalArgumentException("DbSource can't be null in exportNode");
         } else if ((dbm == null) || !dbm.isRelational()) {
@@ -448,7 +448,7 @@ public final class NodeManager {
             insertRelationalNode(node, dbm, dbs.getConnection());
         }
     }
-    
+
     /**
      *  Insert a node into a different (relational) database than its default one.
      */
@@ -493,7 +493,7 @@ public final class NodeManager {
 
             for (int i = 0; i < columns.length; i++) {
                 DbColumn col = columns[i];
-                if (!col.isMapped()) 
+                if (!col.isMapped())
                     continue;
                 if (col.isIdField()) {
                     setStatementValue(stmt, columnNumber, node.getID(), col);
@@ -502,7 +502,7 @@ public final class NodeManager {
                 } else {
                     Relation rel = col.getRelation();
                     Property p = rel == null ? null : node.getProperty(rel.getPropName());
- 
+
                     if (p != null) {
                         setStatementValue(stmt, columnNumber, p, col.getType());
                     } else if (col.isNameField()) {
@@ -544,7 +544,7 @@ public final class NodeManager {
             app.logError("Error invoking onPersist()", x);
         }
     }
-    
+
     /**
      *  Updates a modified node in the embedded db or an external relational database, depending
      * on its database mapping.
@@ -554,7 +554,7 @@ public final class NodeManager {
      */
     public boolean updateNode(IDatabase db, ITransaction txn, Node node)
                     throws IOException, SQLException, ClassNotFoundException {
-        
+
         invokeOnPersist(node);
         DbMapping dbm = node.getDbMapping();
         boolean markMappingAsUpdated = false;
@@ -1023,7 +1023,7 @@ public final class NodeManager {
 
         return retval;
     }
-    
+
     protected List collectMissingKeys(SubnodeList list, int start, int length) {
         List retval = null;
         for (int i = start; i < start + length; i++) {
@@ -1318,7 +1318,7 @@ public final class NodeManager {
 
                 DbColumn[] columns = dbm.getColumns();
                 Relation[] joins = dbm.getJoins();
-                
+
                 StringBuffer b = dbm.getSelect(null).append("WHERE ");
                 dbm.appendCondition(b, idfield, kstr);
                 dbm.addJoinConstraints(b, " AND ");
@@ -1718,21 +1718,28 @@ public final class NodeManager {
         }
     }
 
-    /** 
+    /**
-     * Add a listener that is notified each time a transaction commits 
+     * Returns a map with statistics about the cache
+     */
+    public Map getCacheStatistics() {
+        return cache.getStatistics();
+    }
+
+    /**
+     * Add a listener that is notified each time a transaction commits
      * that adds, modifies or deletes any Nodes.
      */
     public void addNodeChangeListener(NodeChangeListener listener) {
         listeners.add(listener);
     }
-    
+
-    /** 
+    /**
-     * Remove a previously added NodeChangeListener. 
+     * Remove a previously added NodeChangeListener.
      */
     public void removeNodeChangeListener(NodeChangeListener listener) {
         listeners.remove(listener);
     }
-    
+
     /**
      * Let transactors know if they should collect and fire NodeChangeListener
      * events
@@ -1740,7 +1747,7 @@ public final class NodeManager {
     protected boolean hasNodeChangeListeners() {
         return listeners.size() > 0;
     }
-    
+
     /**
      * Called by transactors after committing.
      */
@@ -1757,7 +1764,7 @@ public final class NodeManager {
             }
         }
     }
-    
+
     private void setStatementValue(PreparedStatement stmt, int columnNumber, String value, DbColumn col)
             throws SQLException {
         if (value == null) {
@@ -1780,7 +1787,7 @@ public final class NodeManager {
                     stmt.setBoolean(stmtNumber, p.getBooleanValue());
 
                     break;
-                
+
                 case Types.TINYINT:
                 case Types.BIGINT:
                 case Types.SMALLINT:
@@ -1833,7 +1840,7 @@ public final class NodeManager {
                     String val = p.getStringValue();
                     Reader isr = new StringReader (val);
                     stmt.setCharacterStream (stmtNumber,isr, val.length());
-                    
+
                     break;
 
                 case Types.CHAR:

src/helma/util/CacheMap.java

@@ -277,7 +277,7 @@ public class CacheMap implements ObjectCache {
         return true;
     }
 
-    /// Called when the application using this cache is stopped. We 
+    /// Called when the application using this cache is stopped. We
     //  simply clear out our cache contents.
     public synchronized void shutdown() {
         clear();
@@ -331,6 +331,12 @@ public class CacheMap implements ObjectCache {
         return new HashMap(capacity, loadFactor);
     }
 
+    public Map<String,Object> getStatistics() {
+        Map<String,Object> stats = new HashMap<String,Object>();
+        stats.put("size", size());
+        stats.put("threshold", threshold);
+        return stats;
+    }
 }