/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache Jetspeed" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache" or
* "Apache Jetspeed", nor may "Apache" appear in their name, without
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*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.jetspeed.om.registry.base;
import org.apache.jetspeed.om.registry.RegistryEntry;
import org.apache.jetspeed.om.registry.InvalidEntryException;
import java.util.Map;
import java.util.TreeMap;
import java.util.List;
import java.util.Iterator;
import java.util.Enumeration;
import java.util.Vector;
/**
* Provides a basic registry implementation that keep the elements
* ordered.
*
* @author <a href="mailto:raphael@apache.org">Rapha�l Luta</a>
* @version $Id: BaseOrderedRegistry.java,v 1.1 2002/11/07 20:20:32 raphael Exp $
*/
public class BaseOrderedRegistry implements LocalRegistry
{
protected static final boolean DEBUG = false;
protected List entries = new Vector();
protected Map idx = null;
/** @see Registry#getEntryCount */
public int getEntryCount()
{
return this.entries.size();
}
/** @see Registry#getEntry */
public RegistryEntry getEntry( String name ) throws InvalidEntryException
{
RegistryEntry entry = null;
try
{
if (idx == null)
{
synchronized (entries)
{
buildIdx();
}
}
if (name != null)
{
synchronized (entries)
{
Integer pos = ((Integer)idx.get(name));
if (pos == null)
{
throw new InvalidEntryException( InvalidEntryException.ENTRY_DOES_NOT_EXIST+" "+name );
}
entry = (RegistryEntry)entries.get(pos.intValue()) ;
}
}
}
catch(Exception e)
{
// this will happen if for some reasons the index and vector are desynchronized.
// before throwing an exception, rebuild the idx to prevent further errors
synchronized(entries)
{
buildIdx();
}
throw new InvalidEntryException( InvalidEntryException.ENTRY_DOES_NOT_EXIST+" "+name );
}
return entry;
}
/**
@see Registry#setEntry
*/
public void setEntry( RegistryEntry entry ) throws InvalidEntryException
{
setLocalEntry( entry );
}
/**
@see Registry#addEntry
*/
public void addEntry( RegistryEntry entry ) throws InvalidEntryException
{
addLocalEntry( entry );
}
/**
@see Registry#removeEntry
*/
public void removeEntry( String name )
{
removeLocalEntry( name );
}
/**
@see Registry#removeEntry
*/
public void removeEntry( RegistryEntry entry )
{
removeLocalEntry( entry );
}
/**
@see Registry#hasEntry
*/
public boolean hasEntry( String name )
{
synchronized (entries)
{
if (idx == null)
{
buildIdx();
}
}
return this.idx.containsKey( name );
}
/**
@see Registry#getEntries
*/
public Enumeration getEntries()
{
Vector v = new Vector(entries);
return v.elements();
}
/**
@see Registry#listEntryNames
*/
public Iterator listEntryNames()
{
synchronized (entries)
{
if (idx == null)
{
buildIdx();
}
}
return this.idx.keySet().iterator();
}
/**
@see Registry#toArray
*/
public RegistryEntry[] toArray()
{
RegistryEntry[] array = new RegistryEntry[ entries.size() ];
return (RegistryEntry[])entries.toArray(array);
}
/**
* Creates a new RegistryEntry instance compatible with the current
* Registry instance implementation
*
* @return the newly created RegistryEntry
*/
public RegistryEntry createEntry()
{
return new BaseRegistryEntry();
}
// RegistryService specific methods
/**
* This method is used to only set the entry in the local
* memory cache of the registry without any coherency check with
* persistent storage
*
* @param entry the RegistryEntry to store
*/
public void setLocalEntry( RegistryEntry entry ) throws InvalidEntryException
{
synchronized (entries)
{
if (idx == null)
{
buildIdx();
}
if ( this.idx.containsKey( entry.getName() ) == false )
{
throw new InvalidEntryException( InvalidEntryException.ENTRY_DOES_NOT_EXIST+" "+entry.getName());
}
int pos = ((Integer)idx.get(entry.getName())).intValue();
this.entries.set( pos, entry );
}
}
/**
* This method is used to only add the entry in the local
* memory cache of the registry without any coherency check with
* persistent storage
*
* @param entry the RegistryEntry to store
*/
public void addLocalEntry( RegistryEntry entry ) throws InvalidEntryException
{
synchronized (entries)
{
if (idx == null)
{
buildIdx();
}
if ( this.idx.containsKey( entry.getName() ) )
{
throw new InvalidEntryException( InvalidEntryException.ENTRY_ALREADY_PRESENT );
}
int pos = this.entries.size();
this.entries.add( entry );
this.idx.put( entry.getName(), new Integer(pos) );
}
}
/**
* This method is used to only remove the entry from the local
* memory cache of the registry without any coherency check with
* persistent storage
*
* @param name the name of the RegistryEntry to remove
*/
public void removeLocalEntry( String name )
{
synchronized(entries)
{
if (idx == null)
{
buildIdx();
}
if (this.idx.containsKey(name))
{
int pos = ((Integer)idx.get(name)).intValue();
this.entries.remove( pos );
buildIdx();
}
}
}
/**
* This method is used to only remove the entry from the local
* memory cache of the registry without any coherency check with
* persistent storage
*
* @param entry the RegistryEntry to remove
*/
public void removeLocalEntry( RegistryEntry entry )
{
synchronized(entries)
{
if (entries.remove( entry ))
{
buildIdx();
}
}
}
/**
* Build a lookup index of entries
*/
private void buildIdx()
{
Map map = new TreeMap();
for (int i=0; i < entries.size(); i++)
{
RegistryEntry entry = (RegistryEntry)entries.get(i);
map.put( entry.getName(), new Integer(i));
}
this.idx = map;
}
}