svn commit: r988929 - in /felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl: CachingPersistenceManagerProxy.java ConfigurationManager.java PersistenceManagerProxy.java

[fm...@apache.org]

Author: fmeschbe
Date: Wed Aug 25 09:32:36 2010
New Revision: 988929

URL: http://svn.apache.org/viewvc?rev=988929&view=rev
Log:
FELIX-2552 Add chaching layer for the PersistenceManager services and remove unused PeristenceManagerProxy class

Added:
    felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/CachingPersistenceManagerProxy.java   (with props)
Removed:
    felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/PersistenceManagerProxy.java
Modified:
    felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/ConfigurationManager.java

Added: felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/CachingPersistenceManagerProxy.java
URL: http://svn.apache.org/viewvc/felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/CachingPersistenceManagerProxy.java?rev=988929&view=auto
==============================================================================
--- felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/CachingPersistenceManagerProxy.java (added)
+++ felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/CachingPersistenceManagerProxy.java Wed Aug 25 09:32:36 2010
@@ -0,0 +1,201 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.felix.cm.impl;
+
+
+import java.io.IOException;
+import java.util.Dictionary;
+import java.util.Enumeration;
+import java.util.Hashtable;
+import java.util.Map;
+
+import org.apache.felix.cm.PersistenceManager;
+import org.osgi.framework.Constants;
+
+
+/**
+ * The <code>CachingPersistenceManagerProxy</code> adds a caching layer to the
+ * underlying actual {@link PersistenceManager} implementation. All API calls
+ * are also (or primarily) routed through a local cache of dictionaries indexed
+ * by the <code>service.pid</code>.
+ */
+class CachingPersistenceManagerProxy implements PersistenceManager
+{
+
+    /** the actual PersistenceManager */
+    private final PersistenceManager pm;
+
+    /** cached dictionaries */
+    private final Hashtable cache;
+
+    /**
+     * Indicates whether the getDictionaries method has already been called
+     * and the cache is complete with respect to the contents of the underlying
+     * persistence manager.
+     */
+    private boolean fullyLoaded;
+
+
+    /**
+     * Creates a new caching layer for the given actual {@link PersistenceManager}.
+     * @param pm The actual {@link PersistenceManager}
+     */
+    public CachingPersistenceManagerProxy( final PersistenceManager pm )
+    {
+        this.pm = pm;
+        this.cache = new Hashtable();
+    }
+
+
+    /**
+     * Remove the configuration with the given PID. This implementation removes
+     * the entry from the cache before calling the underlying persistence
+     * manager.
+     */
+    public void delete( String pid ) throws IOException
+    {
+        cache.remove( pid );
+        pm.delete( pid );
+    }
+
+
+    /**
+     * Checks whether a dictionary with the given pid exists. First checks for
+     * the existence in the cache. If not in the cache the underlying
+     * persistence manager is asked.
+     */
+    public boolean exists( String pid )
+    {
+        return cache.containsKey( pid ) || pm.exists( pid );
+    }
+
+
+    /**
+     * Returns an <code>Enumeration</code> of <code>Dictionary</code> objects
+     * representing the configurations stored in the underlying persistence
+     * managers. The dictionaries returned are garanteed to contain the
+     * <code>service.pid</code> property.
+     * <p>
+     * Note, that each call to this method will return new dictionary objects.
+     * That is modifying the contents of a dictionary returned from this method
+     * has no influence on the dictionaries stored in the cache.
+     */
+    public Enumeration getDictionaries() throws IOException
+    {
+        // if not fully loaded, call back to the underlying persistence
+        // manager and cach all dictionaries whose service.pid is set
+        if ( !fullyLoaded )
+        {
+            Enumeration fromPm = pm.getDictionaries();
+            while ( fromPm.hasMoreElements() )
+            {
+                Dictionary next = ( Dictionary ) fromPm.nextElement();
+                String pid = ( String ) next.get( Constants.SERVICE_PID );
+                if ( pid != null )
+                {
+                    cache.put( pid, next );
+                }
+            }
+            fullyLoaded = true;
+        }
+
+        return new Enumeration()
+        {
+            final Enumeration base = cache.elements();
+
+
+            public boolean hasMoreElements()
+            {
+                return base.hasMoreElements();
+            }
+
+
+            public Object nextElement()
+            {
+                return copy( ( Dictionary ) base.nextElement() );
+            }
+        };
+    }
+
+
+    /**
+     * Returns the dictionary for the given PID or <code>null</code> if no
+     * such dictionary is stored by the underyling persistence manager. This
+     * method caches the returned dictionary for future use after retrieving
+     * if from the persistence manager.
+     * <p>
+     * Note, that each call to this method will return new dictionary instance.
+     * That is modifying the contents of a dictionary returned from this method
+     * has no influence on the dictionaries stored in the cache.
+     */
+    public Dictionary load( String pid ) throws IOException
+    {
+        Dictionary loaded = ( Dictionary ) cache.get( pid );
+        if ( loaded == null )
+        {
+            loaded = pm.load( pid );
+            if ( loaded != null )
+            {
+                cache.put( pid, loaded );
+            }
+        }
+        return copy( loaded );
+    }
+
+
+    /**
+     * Stores the dictionary in the cache and in the underlying persistence
+     * manager. This method first calls the underlying persistence manager
+     * before updating the dictionary in the cache.
+     * <p>
+     * Note, that actually a copy of the dictionary is stored in the cache. That
+     * is subsequent modification to the given dictionary has no influence on
+     * the cached data.
+     */
+    public void store( String pid, Dictionary properties ) throws IOException
+    {
+        pm.store( pid, properties );
+        cache.put( pid, copy( properties ) );
+    }
+
+
+    /**
+     * Creates and returns a copy of the given dictionary. This method simply
+     * copies all entries from the source dictionary to the newly created
+     * target.
+     */
+    Dictionary copy( final Dictionary source )
+    {
+        Hashtable copy = new Hashtable();
+        if ( source instanceof Map )
+        {
+            copy.putAll( ( Map ) source );
+        }
+        else
+        {
+            Enumeration keys = source.keys();
+            while ( keys.hasMoreElements() )
+            {
+                Object key = keys.nextElement();
+                copy.put( key, source.get( key ) );
+            }
+        }
+        return copy;
+    }
+}

Propchange: felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/CachingPersistenceManagerProxy.java
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    svn:eol-style = native

Propchange: felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/CachingPersistenceManagerProxy.java
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    svn:keywords = Author Date Id Revision Rev Url

Modified: felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/ConfigurationManager.java
URL: http://svn.apache.org/viewvc/felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/ConfigurationManager.java?rev=988929&r1=988928&r2=988929&view=diff
==============================================================================
--- felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/ConfigurationManager.java (original)
+++ felix/trunk/configadmin/src/main/java/org/apache/felix/cm/impl/ConfigurationManager.java Wed Aug 25 09:32:36 2010
@@ -665,7 +665,7 @@ public class ConfigurationManager implem
                     Object service = persistenceManagerTracker.getService( ref );
                     if ( service != null )
                     {
-                        pmList.add( service );
+                        pmList.add( new CachingPersistenceManagerProxy( ( PersistenceManager ) service ) );
                     }
                 }