1 files changed, 158 insertions, 0 deletions
diff --git a/web/bundles/org.eclipse.jst.jsp.core/src/org/eclipse/jst/jsp/core/internal/java/StackMap.java b/web/bundles/org.eclipse.jst.jsp.core/src/org/eclipse/jst/jsp/core/internal/java/StackMap.java
new file mode 100644
index 0000000000..24126871d2
--- /dev/null
+++ b/web/bundles/org.eclipse.jst.jsp.core/src/org/eclipse/jst/jsp/core/internal/java/StackMap.java
@@ -0,0 +1,158 @@
+/*******************************************************************************
+ * Copyright (c) 2007 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.jst.jsp.core.internal.java;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Stack;
+
+/**
+ * @author nitin
+ * 
+ */
+class StackMap {
+
+	private Map fInternalMap = null;
+
+	public StackMap() {
+		fInternalMap = new HashMap();
+	}
+
+	/**
+	 * Removes all mappings from this StackMap
+	 */
+	public void clear() {
+		fInternalMap.clear();
+	}
+
+	/**
+	 * Returns the most recently pushed value to which this map maps the
+	 * specified key. Returns <tt>null</tt> if the map contains no mapping
+	 * for this key.
+	 * 
+	 * @param key
+	 *            key whose associated value is to be returned.
+	 * @return the most recently put value to which this map maps the
+	 *         specified key, or <tt>null</tt> if the map contains no
+	 *         mapping for this key.
+	 */
+	public Object peek(Object key) {
+		Stack stack = (Stack) fInternalMap.get(key);
+		if (stack != null) {
+			Object o = stack.peek();
+			if (stack.isEmpty()) {
+				fInternalMap.remove(key);
+			}
+			return o;
+		}
+		return null;
+	}
+
+	/**
+	 * Associates the specified value with the specified key in this map. If
+	 * the map previously contained a mapping for this key, the old value is
+	 * pushed onto the top of this key's private stack.
+	 * 
+	 * @param key
+	 *            key with which the specified value is to be associated.
+	 * @param value
+	 *            value to be associated with the specified key.
+	 * @return newest value associated with specified key
+	 * 
+	 * @throws UnsupportedOperationException
+	 *             if the <tt>put</tt> operation is not supported by this
+	 *             StackMap.
+	 * @throws ClassCastException
+	 *             if the class of the specified key or value prevents it from
+	 *             being stored in this StackMap.
+	 * @throws IllegalArgumentException
+	 *             if some aspect of this key or value prevents it from being
+	 *             stored in this StackMap.
+	 * @throws NullPointerException,
+	 *             as this map does not permit <tt>null</tt> keys or values
+	 */
+	public Object push(Object key, Object value) {
+		Stack stack = (Stack) fInternalMap.get(key);
+		if (stack == null) {
+			stack = new Stack();
+			fInternalMap.put(key, stack);
+		}
+		Object o = stack.push(value);
+		return o;
+	}
+
+	/**
+	 * Removes the most-recent mapping for this key from this StackMap if it
+	 * is present.
+	 * 
+	 * <p>
+	 * Returns the value to which the map previously associated the key, or
+	 * <tt>null</tt> if the map contained no mapping for this key. The map
+	 * will not contain a mapping for the specified key once the call returns.
+	 * 
+	 * @param key
+	 *            key whose stack is to be popped
+	 * @return most-recently pushed value associated with specified key, or
+	 *         <tt>null</tt> if there was no mapping for key.
+	 * 
+	 * @throws ClassCastException
+	 *             if the key is of an inappropriate type for this map.
+	 * @throws NullPointerException
+	 *             if the key is <tt>null</tt> as this class does not permit
+	 *             <tt>null</tt> keys
+	 */
+	public Object pop(Object key) {
+		Stack stack = (Stack) fInternalMap.get(key);
+		if (stack != null) {
+			Object o = stack.pop();
+			if (stack.isEmpty()) {
+				fInternalMap.remove(key);
+			}
+			return o;
+		}
+		return null;
+	}
+
+    /**
+	 * Returns the number of entries in this StackMap, the sum of the sizes of
+	 * every remembered stack.
+	 * 
+	 * @return the number of entries in this map.
+	 */
+	int size() {
+		int size = 0;
+		Iterator i = fInternalMap.values().iterator();
+		while (i.hasNext()) {
+			Collection c = (Collection) i.next();
+			size += c.size();
+		}
+		return size;
+	}
+
+	/**
+	 * Returns all of the values of this StackMap.
+	 * 
+	 * @return the values of every Stack within this StackMap.
+	 */
+	Collection values() {
+		Collection values = new LinkedList();
+		Iterator i = fInternalMap.values().iterator();
+		while (i.hasNext()) {
+			Collection c = (Collection) i.next();
+			values.addAll(c);
+		}
+		return values;
+	}
+}