ImpactTraversal.java

/**
 * Copyright (C) 2012 Red Hat, Inc. (jdcasey@commonjava.org)
 *
 * 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 org.commonjava.cartographer.graph.traverse;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.commonjava.maven.atlas.graph.rel.DependencyRelationship;
import org.commonjava.maven.atlas.graph.rel.PluginRelationship;
import org.commonjava.maven.atlas.graph.rel.ProjectRelationship;
import org.commonjava.maven.atlas.ident.ref.ProjectVersionRef;

public class ImpactTraversal
    extends AbstractTraversal
{

    private final Map<ProjectVersionRef, Set<List<ProjectRelationship<?, ?>>>> impactedPaths =
        new HashMap<ProjectVersionRef, Set<List<ProjectRelationship<?, ?>>>>();

    private final boolean includeManagedInfo;

    public ImpactTraversal( final ProjectVersionRef... targets )
    {
        this( false, targets );
    }

    public ImpactTraversal( final boolean includeManagedInfo, final ProjectVersionRef... targets )
    {
        this.includeManagedInfo = includeManagedInfo;
        for ( final ProjectVersionRef target : targets )
        {
            impactedPaths.put( target, new HashSet<List<ProjectRelationship<?, ?>>>() );
        }
    }

    public ImpactTraversal( final Set<ProjectVersionRef> targets )
    {
        this( false, targets );
    }

    public ImpactTraversal( final boolean includeManagedInfo, final Set<ProjectVersionRef> targets )
    {
        this.includeManagedInfo = includeManagedInfo;
        for ( final ProjectVersionRef target : targets )
        {
            impactedPaths.put( target, new HashSet<List<ProjectRelationship<?, ?>>>() );
        }
    }

    public Map<ProjectVersionRef, Set<List<ProjectRelationship<?, ?>>>> getImpactedPaths()
    {
        return impactedPaths;
    }

    @Override
    public boolean traverseEdge( final ProjectRelationship<?, ?> relationship, final List<ProjectRelationship<?, ?>> path )
    {
        if ( !preCheck( relationship, path ) )
        {
            return false;
        }

        final ProjectVersionRef target = relationship.getTarget()
                                                     .asProjectVersionRef();
        final Set<List<ProjectRelationship<?, ?>>> paths = impactedPaths.get( target );
        final ArrayList<ProjectRelationship<?, ?>> p = new ArrayList<ProjectRelationship<?, ?>>( path );
        p.add( relationship );

        paths.add( p );

        // we may yet encounter the impact targets, so allow this traverse to proceed.
        return true;
    }

    @Override
    public boolean preCheck( final ProjectRelationship<?, ?> relationship, final List<ProjectRelationship<?, ?>> path )
    {
        if ( !includeManagedInfo )
        {
            if ( relationship instanceof DependencyRelationship
                && ( (DependencyRelationship) relationship ).isManaged() )
            {
                return false;
            }

            if ( relationship instanceof PluginRelationship && ( (PluginRelationship) relationship ).isManaged() )
            {
                return false;
            }
        }

        final Set<List<ProjectRelationship<?, ?>>> paths = impactedPaths.get( relationship.getTarget()
                                                                                       .asProjectVersionRef() );
        return !( paths != null && paths.isEmpty() );

    }

}