package org.drools.reteoo;
/*
* $Id: ReteTuple.java,v 1.66 2005/02/02 00:23:22 mproctor Exp $
*
* Copyright 2001-2003 (C) The Werken Company. All Rights Reserved.
*
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain copyright statements and
* notices. Redistributions must also contain a copy of this document.
*
* 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 name "drools" must not be used to endorse or promote products derived
* from this Software without prior written permission of The Werken Company.
* For written permission, please contact bob@werken.com.
*
* 4. Products derived from this Software may not be called "drools" nor may
* "drools" appear in their names without prior written permission of The Werken
* Company. "drools" is a trademark of The Werken Company.
*
* 5. Due credit should be given to The Werken Company. (http://werken.com/)
*
* THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE WERKEN COMPANY OR ITS CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND 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.
*
*/
import java.io.Serializable;
import org.drools.FactHandle;
import org.drools.NoSuchFactHandleException;
import org.drools.NoSuchFactObjectException;
import org.drools.WorkingMemory;
import org.drools.rule.Declaration;
import org.drools.spi.Tuple;
/**
* Base Rete-OO <code>Tuple</code> implementation.
*
* @see Tuple
*
* @author <a href="mailto:bob@werken.com">bob mcwhirter </a>
*/
class ReteTuple
implements
Tuple,
Serializable
{
// ------------------------------------------------------------
// Instance members
// ------------------------------------------------------------
private final WorkingMemoryImpl workingMemory;
private final TupleKey key;
private FactHandleImpl mostRecentFact;
private FactHandleImpl leastRecentFact;
// ------------------------------------------------------------
// Constructors
// ------------------------------------------------------------
ReteTuple( WorkingMemoryImpl workingMemory )
{
this.workingMemory = workingMemory;
this.key = TupleKey.EMPTY_KEY;
}
ReteTuple(ReteTuple left,
ReteTuple right)
{
this.workingMemory = left.workingMemory;
this.key = new TupleKey( left.key,
right.key );
}
ReteTuple( WorkingMemoryImpl workingMemory,
Declaration declaration,
FactHandle handle )
{
this.workingMemory = workingMemory;
this.key = new TupleKey( declaration,
handle );
}
public String toString()
{
return "{" + key.getDeclarations( ) + "}";
}
// ------------------------------------------------------------
// Instance methods
// ------------------------------------------------------------
/**
* Retrieve the key for this tuple.
*
* @return The key.
*/
TupleKey getKey()
{
return this.key;
}
/**
* Determine if this tuple depends upon a specified object.
*
* @param handle
* The object handle to test.
*
* @return <code>true</code> if this tuple depends upon the specified
* object, otherwise <code>false</code>.
*/
boolean dependsOn(FactHandle handle)
{
return this.key.containsFactHandle( handle );
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
/**
* @see Tuple
*/
public Object get(Declaration declaration)
{
FactHandle handle = this.key.get( declaration );
if (handle != null)
{
try
{
return this.workingMemory.getObject( handle );
}
catch ( NoSuchFactObjectException e )
{
}
}
return null;
}
/**
* @see Tuple
*/
public FactHandle getFactHandleForObject(Object object)
{
try
{
return this.workingMemory.getFactHandle( object );
}
catch ( NoSuchFactHandleException e )
{
return null;
}
}
public WorkingMemory getWorkingMemory()
{
return this.workingMemory;
}
public long getMostRecentFactTimeStamp()
{
if ( this.mostRecentFact == null )
{
this.mostRecentFact = this.key.getMostRecentFact( );
}
return this.mostRecentFact.getRecency( );
}
public long getLeastRecentFactTimeStamp()
{
if ( this.leastRecentFact == null )
{
this.leastRecentFact = this.key.getLeastRecentFact( );
}
return this.leastRecentFact.getRecency( );
}
}