1 files changed, 122 insertions, 0 deletions
diff --git a/dom/xslt/base/txStack.h b/dom/xslt/base/txStack.h
new file mode 100644
index 000000000..53ce29862
--- /dev/null
+++ b/dom/xslt/base/txStack.h
@@ -0,0 +1,122 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef txStack_h___
+#define txStack_h___
+
+#include "nsTArray.h"
+
+class txStack : private nsTArray<void*>
+{
+public:
+    /**
+     * Returns the specified object from the top of this stack,
+     * without removing it from the stack.
+     *
+     * @return a pointer to the object that is the top of this stack.
+     */
+    inline void* peek()
+    {
+        NS_ASSERTION(!isEmpty(), "peeking at empty stack");
+        return !isEmpty() ? ElementAt(Length() - 1) : nullptr;
+    }
+
+    /**
+     * Adds the specified object to the top of this stack.
+     *
+     * @param obj a pointer to the object that is to be added to the
+     * top of this stack.
+     */
+    inline nsresult push(void* aObject)
+    {
+        return AppendElement(aObject) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    /**
+     * Removes and returns the specified object from the top of this
+     * stack.
+     *
+     * @return a pointer to the object that was the top of this stack.
+     */
+    inline void* pop()
+    {
+        void* object = nullptr;
+        NS_ASSERTION(!isEmpty(), "popping from empty stack");
+        if (!isEmpty())
+        {
+            const uint32_t count = Length() - 1;
+            object = ElementAt(count);
+            RemoveElementAt(count);
+        }
+        return object;
+    }
+
+    /**
+     * Returns true if there are no objects in the stack.
+     *
+     * @return true if there are no objects in the stack.
+     */
+    inline bool isEmpty()
+    {
+        return IsEmpty();
+    }
+
+    /**
+     * Returns the number of elements in the Stack.
+     *
+     * @return the number of elements in the Stack.
+     */
+    inline int32_t size()
+    {
+        return Length();
+    }
+
+private:
+    friend class txStackIterator;
+};
+
+class txStackIterator
+{
+public:
+    /**
+     * Creates an iterator for the given stack.
+     *
+     * @param aStack the stack to create an iterator for.
+     */
+    inline
+    explicit txStackIterator(txStack* aStack) : mStack(aStack),
+                                                mPosition(0)
+    {
+    }
+
+    /**
+     * Returns true if there is more objects on the stack.
+     *
+     * @return .
+     */
+    inline bool hasNext()
+    {
+        return (mPosition < mStack->Length());
+    }
+
+    /**
+     * Returns the next object pointer from the stack.
+     *
+     * @return .
+     */
+    inline void* next()
+    {
+        if (mPosition == mStack->Length()) {
+            return nullptr;
+        }
+        return mStack->ElementAt(mPosition++);
+    }
+
+private:
+    txStack* mStack;
+    uint32_t mPosition;
+};
+
+#endif /* txStack_h___ */