cvs commit: spice/sandbox/metaclass/src/java/org/realityforge/metaclass/introspector CachingMetaClassAccessor.java DefaultMetaClassRegistry.java MetaClassRegistry.java

donaldp     03/10/27 22:40:56

  Added:       sandbox/metaclass/src/java/org/realityforge/metaclass/introspector
                        CachingMetaClassAccessor.java
  Removed:     sandbox/metaclass/src/java/org/realityforge/metaclass/introspector
                        DefaultMetaClassRegistry.java
                        MetaClassRegistry.java
  Log:
  Rewrite registry as a CachingMetaClassAccessor as thats all we really need.
  
  Revision  Changes    Path
  1.1                  spice/sandbox/metaclass/src/java/org/realityforge/metaclass/introspector/CachingMetaClassAccessor.java
  
  Index: CachingMetaClassAccessor.java
  ===================================================================
  package org.realityforge.metaclass.introspector;
  
  import java.util.Map;
  import java.util.WeakHashMap;
  
  import org.realityforge.metaclass.model.ClassDescriptor;
  
  /**
   * Caching MetaClassAccessor implementation.
   *
   * @author <a href="mailto:peter at realityforge.org">Peter Donald</a>
   * @version $Revision: 1.1 $ $Date: 2003/10/28 06:40:56 $
   */
  public class CachingMetaClassAccessor
     implements MetaClassAccessor
  {
     /**
      * Class used to access the MetaData.
      */
     private MetaClassAccessor m_accessor = new DefaultMetaClassAccessor();
  
     /**
      * The cache in which info objects are stored.
      * This cache stores maps for ClassLoaders which in
      * turn stores info for particular classes in
      * classloader.
      */
     private final Map m_cache = new WeakHashMap();
  
     /**
      * Set the MetaClassAccessor to use to locate
      * ClassDescriptor objects.
      *
      * @param accessor the MetaClassAccessor
      */
     public void setAccessor( final MetaClassAccessor accessor )
     {
        if ( null == accessor )
        {
           throw new NullPointerException( "accessor" );
        }
        m_accessor = accessor;
     }
  
     /**
      * Remove all descriptors from registry.
      */
     public void clear()
     {
        m_cache.clear();
     }
  
     /**
      * @see MetaClassAccessor#getClassDescriptor
      */
     public ClassDescriptor getClassDescriptor( final String classname,
                                                final ClassLoader classLoader )
        throws MetaClassException
     {
        if ( null == classname )
        {
           throw new NullPointerException( "classname" );
        }
        if ( null == classLoader )
        {
           throw new NullPointerException( "classLoader" );
        }
        final Map cache = getClassLoaderCache( classLoader );
        ClassDescriptor descriptor = (ClassDescriptor) cache.get( classname );
        if ( null != descriptor )
        {
           return descriptor;
        }
        else
        {
           descriptor = m_accessor.getClassDescriptor( classname, classLoader );
           cache.put( classname, descriptor );
           return descriptor;
        }
     }
  
     /**
      * Register specified descriptor and associated with specified ClassLoader.
      *
      * @param descriptor the descriptor
      * @param classLoader the ClassLoader
      */
     public void registerDescriptor( final ClassDescriptor descriptor,
                                     final ClassLoader classLoader )
     {
        if ( null == descriptor )
        {
           throw new NullPointerException( "descriptor" );
        }
        if ( null == classLoader )
        {
           throw new NullPointerException( "classLoader" );
        }
        final Map cache = getClassLoaderCache( classLoader );
        cache.put( descriptor.getName(), descriptor );
     }
  
     /**
      * Get Cache for specified ClassLoader.
      *
      * @param classLoader the ClassLoader to get cache for
      * @return the Map/Cache for ClassLoader
      */
     private synchronized Map getClassLoaderCache( final ClassLoader classLoader )
     {
        Map map = (Map) m_cache.get( classLoader );
        if ( null == map )
        {
           map = new WeakHashMap();
           m_cache.put( classLoader, map );
        }
        return map;
     }
  }
  
  
  


-------------------------------------------------------
This SF.net email is sponsored by: The SF.net Donation Program.
Do you like what SourceForge.net is doing for the Open
Source Community?  Make a contribution, and help us add new
features and functionality. Click here: http://sourceforge.net/donate/