From 9a73b698d4045fcf19a46193cecde62bb9626bae Mon Sep 17 00:00:00 2001
From: rubidium <rubidium@openttd.org>
Date: Sun, 13 Apr 2008 19:25:14 +0000
Subject: (svn r12695) -Codechange: only allocate window structs when needed.
 Based on a patch by Alberth.

---
 src/core/alloc_type.hpp | 102 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 src/core/alloc_type.hpp

(limited to 'src/core/alloc_type.hpp')

diff --git a/src/core/alloc_type.hpp b/src/core/alloc_type.hpp
new file mode 100644
index 000000000..4146e5ca3
--- /dev/null
+++ b/src/core/alloc_type.hpp
@@ -0,0 +1,102 @@
+
+/* $Id$ */
+
+/** @file alloc_type.hpp Helper types related to the allocation of memory */
+
+#ifndef ALLOC_TYPE_HPP
+#define ALLOC_TYPE_HPP
+
+#include "alloc_func.hpp"
+
+/**
+ * A small 'wrapper' for allocations that can be done on most OSes on the
+ * stack, but are just too large to fit in the stack on devices with a small
+ * stack such as the NDS.
+ * So when it is possible a stack allocation is made, otherwise a heap
+ * allocation is made and this is freed once the struct goes out of scope.
+ * @param T      the type to make the allocation for
+ * @param length the amount of items to allocate
+ */
+template <typename T, size_t length>
+struct SmallStackSafeStackAlloc {
+#if !defined(__NDS__)
+	/** Storing the data on the stack */
+	T data[length];
+#else
+	/** Storing it on the heap */
+	T *data;
+	/** The length (in elements) of data in this allocator. */
+	size_t len;
+
+	/** Allocating the memory */
+	SmallStackSafeStackAlloc() : data(MallocT<T>(length)), len(length) {}
+	/** And freeing when it goes out of scope */
+	~SmallStackSafeStackAlloc() { free(data); }
+#endif
+
+	/**
+	 * Gets a pointer to the data stored in this wrapper.
+	 * @return the pointer.
+	 */
+	inline operator T* () { return data; }
+
+	/**
+	 * Gets a pointer to the data stored in this wrapper.
+	 * @return the pointer.
+	 */
+	inline T* operator -> () { return data; }
+
+	/**
+	 * Gets a pointer to the last data element stored in this wrapper.
+	 * @note needed because endof does not work properly for pointers.
+	 * @return the 'endof' pointer.
+	 */
+	inline T* EndOf() {
+#if !defined(__NDS__)
+		return endof(data);
+#else
+		return &data[len];
+#endif
+	}
+};
+
+/**
+ * Base class that provides memory initialization on dynamically created objects.
+ * All allocated memory will be zeroed.
+ */
+class ZeroedMemoryAllocator
+{
+public:
+	ZeroedMemoryAllocator() {}
+	virtual ~ZeroedMemoryAllocator() {}
+
+	/**
+	 * Memory allocator for a single class instance.
+	 * @param size the amount of bytes to allocate.
+	 * @return the given amounts of bytes zeroed.
+	 */
+	void *operator new(size_t size) { return CallocT<byte>(size); }
+
+	/**
+	 * Memory allocator for an array of class instances.
+	 * @param size the amount of bytes to allocate.
+	 * @return the given amounts of bytes zeroed.
+	 */
+	void *operator new[](size_t size) { return CallocT<byte>(size); }
+
+	/**
+	 * Memory release for a single class instance.
+	 * @param ptr  the memory to free.
+	 * @param size the amount of allocated memory (unused).
+	 */
+	void operator delete(void *ptr, size_t size) { free(ptr); }
+
+	/**
+	 * Memory release for an array of class instances.
+	 * @param ptr  the memory to free.
+	 * @param size the amount of allocated memory (unused).
+	 */
+	void operator delete[](void *ptr, size_t size) { free(ptr); }
+};
+
+#endif /* ALLOC_TYPE_HPP */
-- 
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