Beginnings of a new, better portable FS shell with Haiku FS interface.

Doesn't do anything ATM, but already provides the required system
interface (VFS, caches, POSIX functions).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20859 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/fs_shell/Stack.h

@@ -0,0 +1,87 @@
+/* Stack - a template stack class (plus some handy methods)
+ *
+ * Copyright 2001-2005, Axel Dörfler, [email protected].
+ * This file may be used under the terms of the MIT License.
+ */
+#ifndef _FSSH_STACK_H
+#define _FSSH_STACK_H
+
+
+#include "fssh_defs.h"
+#include "fssh_errors.h"
+
+
+namespace FSShell {
+
+
+template<class T> class Stack {
+	public:
+		Stack()
+			:
+			fArray(NULL),
+			fUsed(0),
+			fMax(0)
+		{
+		}
+
+		~Stack()
+		{
+			free(fArray);
+		}
+
+		bool IsEmpty() const
+		{
+			return fUsed == 0;
+		}
+
+		void MakeEmpty()
+		{
+			// could also free the memory
+			fUsed = 0;
+		}
+
+		fssh_status_t Push(T value)
+		{
+			if (fUsed >= fMax) {
+				fMax += 16;
+				T *newArray = (T *)realloc(fArray, fMax * sizeof(T));
+				if (newArray == NULL)
+					return FSSH_B_NO_MEMORY;
+
+				fArray = newArray;
+			}
+			fArray[fUsed++] = value;
+			return FSSH_B_OK;
+		}
+
+		bool Pop(T *value)
+		{
+			if (fUsed == 0)
+				return false;
+
+			*value = fArray[--fUsed];
+			return true;
+		}
+
+		T *Array()
+		{
+			return fArray;
+		}
+
+		int32_t CountItems() const
+		{
+			return fUsed;
+		}
+
+	private:
+		T		*fArray;
+		int32_t	fUsed;
+		int32_t	fMax;
+};
+
+}	// namespace FSShell
+
+using FSShell::Stack;
+
+
+#endif	/* _FSSH_STACK_H */