1 files changed, 104 insertions, 0 deletions
diff --git a/bundles/org.eclipse.equinox.registry/src/org/eclipse/core/internal/registry/RegistryIndexChildren.java b/bundles/org.eclipse.equinox.registry/src/org/eclipse/core/internal/registry/RegistryIndexChildren.java
new file mode 100644
index 000000000..705c4574a
--- /dev/null
+++ b/bundles/org.eclipse.equinox.registry/src/org/eclipse/core/internal/registry/RegistryIndexChildren.java
@@ -0,0 +1,104 @@
+/*******************************************************************************
+ * Copyright (c) 2006 IBM Corporation and others.
+ * 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:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.core.internal.registry;
+
+public class RegistryIndexChildren {
+
+	static final int[] EMPTY_ARRAY = new int[0];
+
+	private int[] children;
+
+	public RegistryIndexChildren() {
+		children = EMPTY_ARRAY;
+	}
+
+	public RegistryIndexChildren(int[] children) {
+		this.children = children;
+	}
+
+	public int[] getChildren() {
+		return children;
+	}
+
+	public int findChild(int id) {
+		for (int i = 0; i < children.length; i++) {
+			if (children[i] == id)
+				return i;
+		}
+		return -1;
+	}
+
+	public boolean unlinkChild(int id) {
+		int index = findChild(id);
+		if (index == -1)
+			return false; // there is no such element
+
+		// copy the array except one element at index
+		int[] result = new int[children.length - 1];
+		System.arraycopy(children, 0, result, 0, index);
+		System.arraycopy(children, index + 1, result, index, children.length - index - 1);
+		children = result;
+		return true;
+	}
+
+	public boolean linkChild(int id) {
+		if (children.length == 0) {
+			children = new int[] {id};
+			return true;
+		}
+
+		// add new element at the end
+		int[] result = new int[children.length + 1];
+		System.arraycopy(children, 0, result, 0, children.length);
+		result[children.length] = id;
+		children = result;
+		return true;
+	}
+
+	public boolean linkChildren(int[] IDs) {
+		if (children.length == 0) {
+			children = IDs;
+			return true;
+		}
+		int[] result = new int[children.length + IDs.length];
+		System.arraycopy(children, 0, result, 0, children.length);
+		System.arraycopy(IDs, 0, result, children.length, IDs.length);
+		children = result;
+		return true;
+	}
+
+	public boolean unlinkChildren(int[] IDs) {
+		if (children.length == 0)
+			return (IDs.length == 0);
+
+		int size = children.length;
+		for (int i = 0; i < IDs.length; i++) {
+			int index = findChild(IDs[i]);
+			if (index != -1) {
+				children[i] = -1;
+				size--;
+			}
+		}
+		if (size == 0) {
+			children = EMPTY_ARRAY;
+			return true;
+		}
+		int[] result = new int[size];
+		int pos = 0;
+		for (int i = 0; i < children.length; i++) {
+			if (children[i] == -1)
+				continue;
+			result[pos] = children[i];
+			pos++;
+		}
+		return true;
+	}
+}