Add classes from org.eclipse.oomph.p2.core to read eclipse index files

tycho-baseline-plugin/src/main/java/org/eclipse/tycho/copyfrom/oomph/P2Index.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2014, 2016 Eike Stepper (Loehne, Germany) and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v20.html
+ *
+ * Contributors:
+ *    Eike Stepper - initial API and implementation
+ */
+package org.eclipse.oomph.p2.internal.core;
+
+import org.eclipse.emf.common.util.URI;
+
+import org.eclipse.equinox.p2.metadata.Version;
+
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * @author Eike Stepper
+ */
+public interface P2Index
+{
+  public static final int SIMPLE_REPOSITORY = 0;
+
+  public static final int COMPOSED_REPOSITORY = 1;
+
+  public static final P2Index INSTANCE = P2IndexImpl.INSTANCE;
+
+  public Repository[] getRepositories();
+
+  public Map<String, Set<String>> getCapabilities();
+
+  public Map<Repository, Set<Version>> lookupCapabilities(String namespace, String name);
+
+  public Map<Repository, Set<Version>> generateCapabilitiesFromComposedRepositories(Map<Repository, Set<Version>> capabilitiesFromSimpleRepositories);
+
+  /**
+   * @author Eike Stepper
+   */
+  public interface Repository extends Comparable<Repository>
+  {
+    public URI getLocation();
+
+    public int getID();
+
+    public boolean isComposed();
+
+    public boolean isCompressed();
+
+    public long getTimestamp();
+
+    public int getCapabilityCount();
+
+    public int getUnresolvedChildren();
+
+    public Repository[] getChildren();
+
+    public Repository[] getComposites();
+  }
+}