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Diffstat (limited to 'src/core/pool_type.hpp')
-rw-r--r-- | src/core/pool_type.hpp | 284 |
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 */ |