(svn r16380) -Codechange: rename pool.hpp to pool_type.hpp

1 files changed, 284 insertions, 0 deletions

diff --git a/src/core/pool_type.hpp b/src/core/pool_type.hpp
new file mode 100644
index 000000000..2d32df724
--- /dev/null
+++ b/src/core/pool_type.hpp
@@ -0,0 +1,284 @@
+/* $Id$ */
+
+/** @file pool_type.hpp Defintion of Pool, structure used to access PoolItems, and PoolItem, base structure for Vehicle, Town, and other indexed items. */
+
+#ifndef POOL_TYPE_HPP
+#define POOL_TYPE_HPP
+
+template <class Titem, typename Tindex, size_t Tgrowth_step, size_t Tmax_size>
+struct Pool {
+	static const size_t MAX_SIZE = Tmax_size; ///< Make template parameter accessible from outside
+
+	const char * const name; ///< Name of this pool
+
+	size_t size;         ///< Current allocated size
+	size_t first_free;   ///< No item with index lower than this is free (doesn't say anything about this one!)
+	size_t first_unused; ///< This and all higher indexes are free (doesn't say anything about first_unused-1 !)
+	size_t items;        ///< Number of used indexes (non-NULL)
+
+	bool cleaning;       ///< True if cleaning pool (deleting all items)
+
+	Titem **data;        ///< Pointer to array of pointers to Titem
+
+	/** Constructor */
+	Pool(const char *name);
+	/** Destroys all items in the pool and resets all member variables */
+	void CleanPool();
+
+	/**
+	 * Returs Titem with given index
+	 * @param index of item to get
+	 * @return pointer to Titem
+	 * @pre index < this->first_unused
+	 */
+	FORCEINLINE Titem *Get(size_t index)
+	{
+		assert(index < this->first_unused);
+		return this->data[index];
+	}
+
+	/**
+	 * Tests whether given index can be used to get valid (non-NULL) Titem
+	 * @param index index to examine
+	 * @return true if PoolItem::Get(index) will return non-NULL pointer
+	 */
+	FORCEINLINE bool IsValidID(size_t index)
+	{
+		return index < this->first_unused && this->Get(index) != NULL;
+	}
+
+	/**
+	 * Tests whether we can allocate 'n' items
+	 * @param n number of items we want to allocate
+	 * @return true if 'n' items can be allocated
+	 */
+	FORCEINLINE bool CanAllocate(size_t n = 1)
+	{
+		return this->items <= Tmax_size - n;
+	}
+
+	/** Base class for all PoolItems */
+	template <struct Pool<Titem, Tindex, Tgrowth_step, Tmax_size> *Tpool>
+	struct PoolItem {
+		Tindex index; ///< Index of this pool item
+
+		/**
+		 * Allocates space for new Titem
+		 * @param size size of Titem
+		 * @return pointer to allocated memory
+		 * @note can never fail (return NULL), use CanAllocate() to check first!
+		 */
+		FORCEINLINE void *operator new(size_t size)
+		{
+			return Tpool->GetNew(size);
+		}
+
+		/**
+		 * Marks Titem as free. Its memory is released
+		 * @param p memory to free
+		 * @note the item has to be allocated in the pool!
+		 */
+		FORCEINLINE void operator delete(void *p)
+		{
+			Titem *pn = (Titem *)p;
+			assert(pn == Tpool->Get(pn->index));
+			Tpool->FreeItem(pn->index);
+		}
+
+		/**
+		 * Allocates space for new Titem with given index
+		 * @param size size of Titem
+		 * @param index index of item
+		 * @return pointer to allocated memory
+		 * @note can never fail (return NULL), use CanAllocate() to check first!
+		 * @pre index has to be unused! Else it will crash
+		 */
+		FORCEINLINE void *operator new(size_t size, size_t index)
+		{
+			return Tpool->GetNew(size, index);
+		}
+
+		/**
+		 * Deletes item with given index.
+		 * @param p Titem memory to release
+		 * @param index index of item
+		 * @note never use this! Only for internal use
+		 *       (called automatically when constructor of Titem uses throw())
+		 */
+		FORCEINLINE void operator delete(void *p, size_t index)
+		{
+			assert(p == Tpool->Get(index));
+			Tpool->FreeItem(index);
+		}
+
+
+		/**
+		 * Allocates space for new Titem at given memory address
+		 * @param size size of Titem
+		 * @param ptr where are we allocating the item?
+		 * @return pointer to allocated memory (== ptr)
+		 * @note use of this is strongly discouraged
+		 * @pre the memory must not be allocated in the Pool!
+		 */
+		FORCEINLINE void *operator new(size_t size, void *ptr)
+		{
+			for (size_t i = 0; i < Tpool->first_unused; i++) {
+				/* Don't allow creating new objects over existing.
+				 * Even if we called the destructor and reused this memory,
+				 * we don't know whether 'size' and size of currently allocated
+				 * memory are the same (because of possible inheritance).
+				 * Use { size_t index = item->index; delete item; new (index) item; }
+				 * instead to make sure destructor is called and no memory leaks. */
+				assert(ptr != Tpool->data[i]);
+			}
+			return ptr;
+		}
+
+		/**
+		 * Deletes item that was allocated by the function above
+		 * @param p Titem memory to release
+		 * @param ptr parameter given to operator new
+		 * @note never use this! Only for internal use
+		 *       (called automatically when constructor of Titem uses throw())
+		 */
+		FORCEINLINE void operator delete(void *p, void *ptr)
+		{
+			assert(p == ptr);
+			for (size_t i = 0; i < Tpool->first_unused; i++) {
+				assert(ptr != Tpool->data[i]);
+			}
+		}
+
+
+		/** Helper functions so we can use PoolItem::Function() instead of _poolitem_pool.Function() */
+
+		/**
+		 * Tests whether we can allocate 'n' items
+		 * @param n number of items we want to allocate
+		 * @return true if 'n' items can be allocated
+		 */
+		static FORCEINLINE bool CanAllocateItem(size_t n = 1)
+		{
+			return Tpool->CanAllocate(n);
+		}
+
+		/**
+		 * Returns current state of pool cleaning - yes or no
+		 * @return true iff we are cleaning the pool now
+		 */
+		static FORCEINLINE bool CleaningPool()
+		{
+			return Tpool->cleaning;
+		}
+
+		/**
+		 * Tests whether given index can be used to get valid (non-NULL) Titem
+		 * @param index index to examine
+		 * @return true if PoolItem::Get(index) will return non-NULL pointer
+		 */
+		static FORCEINLINE bool IsValidID(size_t index)
+		{
+			return Tpool->IsValidID(index);
+		}
+
+		/**
+		 * Returs Titem with given index
+		 * @param index of item to get
+		 * @return pointer to Titem
+		 * @pre index < this->first_unused
+		 */
+		static FORCEINLINE Titem *Get(size_t index)
+		{
+			return Tpool->Get(index);
+		}
+
+		/**
+		 * Returs Titem with given index
+		 * @param index of item to get
+		 * @return pointer to Titem
+		 * @note returns NULL for invalid index
+		 */
+		static FORCEINLINE Titem *GetIfValid(size_t index)
+		{
+			return index < Tpool->first_unused ? Tpool->Get(index) : NULL;
+		}
+
+		/**
+		 * Returns first unused index. Useful when iterating over
+		 * all pool items.
+		 * @return first unused index
+		 */
+		static FORCEINLINE size_t GetPoolSize()
+		{
+			return Tpool->first_unused;
+		}
+
+		/**
+		 * Returns number of valid items in the pool
+		 * @return number of valid items in the pool
+		 */
+		static FORCEINLINE size_t GetNumItems()
+		{
+			return Tpool->items;
+		}
+	};
+
+private:
+	static const size_t NO_FREE_ITEM = MAX_UVALUE(size_t); ///< Contant to indicate we can't allocate any more items
+
+	/**
+	 * Makes given index valid
+	 * @param size size of item
+	 * @param index index of item
+	 * @pre index < this->size
+	 * @pre this->Get(index) == NULL
+	 */
+	void *AllocateItem(size_t size, size_t index);
+
+	/**
+	 * Resizes the pool so 'index' can be addressed
+	 * @param index index we will allocate later
+	 * @pre index >= this->size
+	 * @pre index < Tmax_size
+	 */
+	void ResizeFor(size_t index);
+
+	/**
+	 * Searches for first free index
+	 * @return first free index, NO_FREE_ITEM on failure
+	 */
+	size_t FindFirstFree();
+
+	/**
+	 * Allocates new item
+	 * @param size size of item
+	 * @return pointer to allocated item
+	 * @note error() on failure! (no free item)
+	 */
+	void *GetNew(size_t size);
+
+	/**
+	 * Allocates new item with given index
+	 * @param size size of item
+	 * @param index index of item
+	 * @return pointer to allocated item
+	 * @note usererror() on failure! (index out of range or already used)
+	 */
+	void *GetNew(size_t size, size_t index);
+
+	/**
+	 * Deallocates memory used by this index and marks item as free
+	 * @param index item to deallocate
+	 * @pre unit is allocated (non-NULL)
+	 * @note 'delete NULL' doesn't cause call of this function, so it is safe
+	 */
+	void FreeItem(size_t index);
+};
+
+#define FOR_ALL_ITEMS_FROM(type, iter, var, start) \
+	for (size_t iter = start; var = NULL, iter < type::GetPoolSize(); iter++) \
+		if ((var = type::Get(iter)) != NULL)
+
+#define FOR_ALL_ITEMS(type, iter, var) FOR_ALL_ITEMS_FROM(type, iter, var, 0)
+
+#endif /* POOL_TYPE_HPP */