Merge tag 'v2.3.20' into testing

[gpl/argeo-jcr.git] / org.argeo.slc.repo / src / org / eclipse / aether / graph / DependencyCycle.java

diff --git a/org.argeo.slc.repo/src/org/eclipse/aether/graph/DependencyCycle.java b/org.argeo.slc.repo/src/org/eclipse/aether/graph/DependencyCycle.java
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+/*******************************************************************************
+ * Copyright (c) 2013, 2014 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.graph;
+
+import java.util.List;
+
+/**
+ * A cycle within a dependency graph, that is a sequence of dependencies d_1, d_2, ..., d_n where d_1 and d_n have the
+ * same versionless coordinates. In more practical terms, a cycle occurs when a project directly or indirectly depends
+ * on its own output artifact.
+ * 
+ * @noimplement This interface is not intended to be implemented by clients.
+ * @noextend This interface is not intended to be extended by clients.
+ */
+public interface DependencyCycle
+{
+
+    /**
+     * Gets the dependencies that lead to the first dependency on the cycle, starting from the root of the dependency
+     * graph.
+     * 
+     * @return The (read-only) sequence of dependencies that precedes the cycle in the graph, potentially empty but
+     *         never {@code null}.
+     */
+    List<Dependency> getPrecedingDependencies();
+
+    /**
+     * Gets the dependencies that actually form the cycle. For example, a -&gt; b -&gt; c -&gt; a, i.e. the last
+     * dependency in this sequence duplicates the first element and closes the cycle. Hence the length of the cycle is
+     * the size of the returned sequence minus 1.
+     * 
+     * @return The (read-only) sequence of dependencies that forms the cycle, never {@code null}.
+     */
+    List<Dependency> getCyclicDependencies();
+
+}