/* ====================================================================
* Loom Software License, version 1.1
*
* Copyright (c) 2003, Loom Group. 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. Neither the name of the Loom Group nor the name "Loom" nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS 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
* COPYRIGHT OWNER OR 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.
*
* ====================================================================
*
* Loom includes code from the Apache Software Foundation
*
* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 1997-2003 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 "Jakarta", "Avalon", and "Apache Software Foundation"
* 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",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``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 APACHE SOFTWARE FOUNDATION 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.
*/
package org.codehaus.loom.components.application;
import java.util.ArrayList;
import org.codehaus.loom.components.util.info.DependencyDescriptor;
import org.codehaus.loom.components.util.metadata.DependencyDirective;
import org.codehaus.loom.components.util.profile.ComponentProfile;
/**
* @author Peter Donald
*/
class DependencyGraph
{
///Private constructor to block instantiation
private DependencyGraph()
{
}
/**
* Method to generate an ordering of nodes to traverse. It is expected that
* the specified Blocks have passed verification tests and are well formed.
*
* @param forward true if forward dependencys traced, false if dependencies
* reversed
* @param blocks the blocks to traverse
* @return the ordered node names
*/
public static String[] walkGraph( final boolean forward,
final ComponentProfile[] blocks )
{
final ArrayList result = new ArrayList();
//temporary storage to record those
//that are already traversed
final ArrayList done = new ArrayList();
for( int i = 0; i < blocks.length; i++ )
{
visitBlock( blocks[ i ], blocks, forward, done, result );
}
return (String[])result.toArray( new String[ 0 ] );
}
private static void visitBlock( final ComponentProfile block,
final ComponentProfile[] blocks,
final boolean forward,
final ArrayList done,
final ArrayList order )
{
//If already visited this block then bug out early
final String name = block.getTemplate().getName();
if( done.contains( name ) )
{
return;
}
done.add( name );
if( forward )
{
visitDependencies( block, blocks, done, order );
}
else
{
visitReverseDependencies( block, blocks, done, order );
}
order.add( name );
}
/**
* Traverse dependencies of specified block.
*
* @param block the BlockMetaData
*/
private static void visitDependencies( final ComponentProfile block,
final ComponentProfile[] blocks,
final ArrayList done,
final ArrayList order )
{
final DependencyDescriptor[] descriptors = block.getInfo()
.getDependencies();
for( int i = 0; i < descriptors.length; i++ )
{
final String key = descriptors[ i ].getKey();
final DependencyDirective[] dependencySet = block.getTemplate()
.getDependencies( key );
for( int j = 0; j < dependencySet.length; j++ )
{
final DependencyDirective dependency = dependencySet[ j ];
final ComponentProfile other = getBlock(
dependency.getProviderName(), blocks );
visitBlock( other, blocks, true, done, order );
}
}
}
/**
* Traverse all reverse dependencies of specified block. A reverse
* dependency are those that dependend on block.
*
* @param block the ComponentProfile
*/
private static void visitReverseDependencies( final ComponentProfile block,
final ComponentProfile[] blocks,
final ArrayList done,
final ArrayList order )
{
final String name = block.getTemplate().getName();
for( int i = 0; i < blocks.length; i++ )
{
final ComponentProfile other = blocks[ i ];
final DependencyDirective[] roles = other.getTemplate()
.getDependencies();
for( int j = 0; j < roles.length; j++ )
{
final String depends = roles[ j ].getProviderName();
if( depends.equals( name ) )
{
visitBlock( other, blocks, false, done, order );
}
}
}
}
/**
* Utility method to get block with specified name from specified array.
*
* @param name the name of block
* @param blocks the Block array
* @return the Block
*/
private static ComponentProfile getBlock( final String name,
final ComponentProfile[] blocks )
{
for( int i = 0; i < blocks.length; i++ )
{
if( blocks[ i ].getTemplate().getName().equals( name ) )
{
return blocks[ i ];
}
}
//Should never happen if Verifier passed checks
throw new IllegalStateException();
}
}