org.argeo.slc.repo/src/org/eclipse/aether/collection/DependencySelector.java

   1 /*******************************************************************************
   2  * Copyright (c) 2010, 2014 Sonatype, Inc.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *    Sonatype, Inc. - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.aether.collection;
  12
  13 import org.eclipse.aether.graph.Dependency;
  14
  15 /**
  16  * Decides what dependencies to include in the dependency graph.
  17  * <p>
  18  * <strong>Note:</strong> Implementations must be stateless.
  19  * <p>
  20  * <em>Warning:</em> This hook is called from a hot spot and therefore implementations should pay attention to
  21  * performance. Among others, implementations should provide a semantic {@link Object#equals(Object) equals()} method.
  22  *
  23  * @see org.eclipse.aether.RepositorySystemSession#getDependencySelector()
  24  * @see org.eclipse.aether.RepositorySystem#collectDependencies(org.eclipse.aether.RepositorySystemSession,
  25  *      CollectRequest)
  26  */
  27 public interface DependencySelector
  28 {
  29
  30     /**
  31      * Decides whether the specified dependency should be included in the dependency graph.
  32      *
  33      * @param dependency The dependency to check, must not be {@code null}.
  34      * @return {@code false} if the dependency should be excluded from the children of the current node, {@code true}
  35      *         otherwise.
  36      */
  37     boolean selectDependency( Dependency dependency );
  38
  39     /**
  40      * Derives a dependency selector for the specified collection context. When calculating the child selector,
  41      * implementors are strongly advised to simply return the current instance if nothing changed to help save memory.
  42      *
  43      * @param context The dependency collection context, must not be {@code null}.
  44      * @return The dependency selector for the target node or {@code null} if dependencies should be unconditionally
  45      *         included in the sub graph.
  46      */
  47     DependencySelector deriveChildSelector( DependencyCollectionContext context );
  48
  49 }