/******************************************************************************* * Copyright (c) 2013 Sonatype, Inc. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Sonatype, Inc. - initial API and implementation *******************************************************************************/ package org.eclipse.aether.util.graph.version; import java.util.Arrays; import java.util.Collection; import org.eclipse.aether.RepositoryException; import org.eclipse.aether.collection.DependencyCollectionContext; import org.eclipse.aether.collection.VersionFilter; /** * A version filter that combines multiple version filters into a chain where each filter gets invoked one after the * other, thereby accumulating their filtering effects. */ public final class ChainedVersionFilter implements VersionFilter { private final VersionFilter[] filters; private int hashCode; /** * Chains the specified version filters. * * @param filter1 The first version filter, may be {@code null}. * @param filter2 The second version filter, may be {@code null}. * @return The chained version filter or {@code null} if both input filters are {@code null}. */ public static VersionFilter newInstance( VersionFilter filter1, VersionFilter filter2 ) { if ( filter1 == null ) { return filter2; } if ( filter2 == null ) { return filter1; } return new ChainedVersionFilter( new VersionFilter[] { filter1, filter2 } ); } /** * Chains the specified version filters. * * @param filters The version filters to chain, must not be {@code null} or contain {@code null}. * @return The chained version filter or {@code null} if the input array is empty. */ public static VersionFilter newInstance( VersionFilter... filters ) { if ( filters.length <= 1 ) { if ( filters.length <= 0 ) { return null; } return filters[0]; } return new ChainedVersionFilter( filters.clone() ); } /** * Chains the specified version filters. * * @param filters The version filters to chain, must not be {@code null} or contain {@code null}. * @return The chained version filter or {@code null} if the input collection is empty. */ public static VersionFilter newInstance( Collection<? extends VersionFilter> filters ) { if ( filters.size() <= 1 ) { if ( filters.isEmpty() ) { return null; } return filters.iterator().next(); } return new ChainedVersionFilter( filters.toArray( new VersionFilter[filters.size()] ) ); } private ChainedVersionFilter( VersionFilter[] filters ) { this.filters = filters; } public void filterVersions( VersionFilterContext context ) throws RepositoryException { for ( int i = 0, n = filters.length; i < n && context.getCount() > 0; i++ ) { filters[i].filterVersions( context ); } } public VersionFilter deriveChildFilter( DependencyCollectionContext context ) { VersionFilter[] children = null; int removed = 0; for ( int i = 0, n = filters.length; i < n; i++ ) { VersionFilter child = filters[i].deriveChildFilter( context ); if ( children != null ) { children[i - removed] = child; } else if ( child != filters[i] ) { children = new VersionFilter[filters.length]; System.arraycopy( filters, 0, children, 0, i ); children[i - removed] = child; } if ( child == null ) { removed++; } } if ( children == null ) { return this; } if ( removed > 0 ) { int count = filters.length - removed; if ( count <= 0 ) { return null; } if ( count == 1 ) { return children[0]; } VersionFilter[] tmp = new VersionFilter[count]; System.arraycopy( children, 0, tmp, 0, count ); children = tmp; } return new ChainedVersionFilter( children ); } @Override public boolean equals( Object obj ) { if ( this == obj ) { return true; } else if ( null == obj || !getClass().equals( obj.getClass() ) ) { return false; } ChainedVersionFilter that = (ChainedVersionFilter) obj; return Arrays.equals( filters, that.filters ); } @Override public int hashCode() { if ( hashCode == 0 ) { int hash = getClass().hashCode(); hash = hash * 31 + Arrays.hashCode( filters ); hashCode = hash; } return hashCode; } }