/**
* Copyright 2007-2008 University Of Southern California
*
* Licensed 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 edu.isi.pegasus.planner.mapper;
import edu.isi.pegasus.planner.classes.ADag;
import edu.isi.pegasus.common.util.DynamicLoader;
import edu.isi.pegasus.planner.classes.PegasusBag;
import edu.isi.pegasus.planner.common.PegasusProperties;
/**
* The factory class that loads an appropriate Transfer OutputMapper class,
* as specified by the properties.
*
* @author Karan Vahi
* @version $Revision$
*/
public class OutputMapperFactory {
/**
* The default package where the implementations reside, which this factory
* loads.
*/
public static final String DEFAULT_PACKAGE_NAME =
"edu.isi.pegasus.planner.mapper.output";
/**
* The prefix for the property subset for connecting to the individual
* catalogs.
*/
public static final String PROPERTY_KEY = "pegasus.dir.storage.mapper";
/**
* The default mapper implementation that is picked up.
*/
public static final String DEFAULT_OUTPUT_MAPPER_IMPLEMENTATION = "Flat";
/**
* The Hashed mapper implementation to be used.
*/
public static final String HASHED_OUTPUT_MAPPER_IMPLEMENTATION = "Hashed";
/**
* Loads the implementing class corresponding to the value specified in the
* properties. If the package name is not specified with the class, then
* class is assumed to be in the DEFAULT_PACKAGE. The properties object passed
* should not be null.
* <p>
* In addition it ends up loading the appropriate Transfer Implementation
* that is required by the mapper.
*
* @param dag the workflow that is being refined.
* @param bag the bag of initialization objects
*
* @return the instance of the class implementing this interface.
*
* @exception TransferOutputMapperException that nests any error that
* might occur during the instantiation.
*
* @see #DEFAULT_PACKAGE_NAME
*/
public static OutputMapper loadInstance( ADag dag,
PegasusBag bag )
throws OutputMapperFactoryException{
PegasusProperties props = bag.getPegasusProperties();
if( props == null ){
throw new OutputMapperFactoryException( "Null Properties passed in the bag ");
}
String className = props.getProperty(PROPERTY_KEY ); //rely on the new mapper property
if( className == null && props.useDeepStorageDirectoryStructure() ){
//if the legacy property is specified, use that to set to HashedMapper
className = HASHED_OUTPUT_MAPPER_IMPLEMENTATION;
}
//fall back to default if not determined from properties
className = ( className == null )?
DEFAULT_OUTPUT_MAPPER_IMPLEMENTATION:
className;
return loadInstance( className, bag, dag );
}
/**
* Loads the implementing class corresponding to the class. If the package
* name is not specified with the class, then class is assumed to be
* in the DEFAULT_PACKAGE. The properties object passed should not be null.
* In addition it ends up loading the appropriate Transfer Implementation
* that is required by the mapper.
*
* @param className the name of the class that implements the mode.It can or
* cannot be with the package name.
* @param bag the bag of initialization objects
* @param dag the workflow that is being refined.
*
* @return the instance of the class implementing this interface.
*
* @exception OutputMapperFactoryException that nests any error that
* might occur during the instantiation.
*
* @see #DEFAULT_PACKAGE_NAME
*/
public static OutputMapper loadInstance( String className,
PegasusBag bag,
ADag dag )
throws OutputMapperFactoryException{
OutputMapper mapper = null;
try{
//sanity check
if ( bag.getPegasusProperties() == null) {
throw new RuntimeException("Invalid properties passed");
}
if (dag == null) {
throw new RuntimeException("Invalid workflow passed");
}
//set the mapper to default if required
if( className == null ){
className = OutputMapperFactory.DEFAULT_OUTPUT_MAPPER_IMPLEMENTATION;
}
//prepend the package name
className = (className.indexOf('.') == -1) ?
//pick up from the default package
DEFAULT_PACKAGE_NAME + "." + className :
//load directly
className;
//try loading the class dynamically
DynamicLoader dl = new DynamicLoader(className);
mapper = (OutputMapper) dl.instantiate( new Object[0]);
//we got the mapper try to load the appropriate
//transfer implementation also
mapper.initialize( bag, dag );
}
catch (Exception e){
throw new OutputMapperFactoryException("Instantiating Output Mapper",
className,
e);
}
return mapper;
}
}