/**
 * @file allocator.h
 * 
 * @brief Interface of allocator_t.
 */

/*
 * Copyright (C) 2005 Jan Hutter, Martin Willi
 * Hochschule fuer Technik Rapperswil
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

#ifndef ALLOCATOR_H_
#define ALLOCATOR_H_

#include <stdlib.h>
#include <stddef.h>
#include <string.h>

#include <types.h>


/**
 * Macro to allocate a special type.
 * 
 * @param thing 		object on which a sizeof is performed
 * @return 
 * 					- Pointer to allocated memory
 * 					- NULL if out of ressources.
 * 
 * @ingroup utils
 */
#define allocator_alloc_thing_as_chunk(thing) (allocator_alloc_as_chunk(sizeof(thing)))

/**
 * Macro to allocate a special type as chunk_t.
 * 
 * @param thing 		object on which a sizeof is performed
 * @return 
 * 					- chunk_t pointing to allocated memory if successful
 * 					- chunk_t containing empty pointer if out of ressources
 *
 * @ingroup utils
 */
#define allocator_alloc_thing(thing) (allocator_alloc(sizeof(thing)))

#ifdef LEAK_DETECTIVE

	typedef struct allocator_t allocator_t;

	/**
 	 *@brief Allocater object use to detect memory leaks.
	 *
	 * @ingroup utils
	 */
	struct allocator_t {
	
		/**
		 * Allocates memory with LEAK_DETECTION and 
		 * returns an empty data area filled with zeros.
		 * 
		 * @warning 		Use this function not directly, only with assigned macros 
		 * 				#allocator_alloc and #allocator_alloc_thing.
		 * 
		 * @param this 	allocator_t object
		 * @param bytes number of bytes to allocate
		 * @param file 	filename from which the memory is allocated
		 * @param line 	line number in specific file
		 * @return 		
		 * 				- pointer to allocated memory area
		 * 				- NULL if out of ressources
		 */ 
		void * (*allocate) (allocator_t *this,size_t bytes, char * file,int line);

		/**
		 * Allocates memory with LEAK_DETECTION and 
		 * returns an chunk pointing to an empy data area filled with zeros.
		 * 
		 * @warning 		Use this function not directly, only with assigned 
		 * 				macros #allocator_alloc_as_chunk and 
		 * 				#allocator_alloc_thing_as_chunk.
		 * 
		 * @param this 	allocator_t object
		 * @param bytes number of bytes to allocate
		 * @param file 	filename from which the memory is allocated
		 * @param line 	line number in specific file
		 * @return 		
		 * 				- pointer to allocated memory area
		 * 				- NULL if out of ressources
		 */ 
		chunk_t (*allocate_as_chunk) (allocator_t *this,size_t bytes, char * file,int line);
	
		/**
		 * Reallocates memory with LEAK_DETECTION and 
		 * returns an empty data area filled with zeros.
		 * 
		 * @warning 		Use this function not directly, only with assigned macro 
		 * 				#allocator_realloc.
		 * 
		 * @param this 	allocator_t object
		 * @param old 	pointer to the old data area
		 * @param bytes number of bytes to allocate
		 * @param file 	filename from which the memory is allocated
		 * @param line 	line number in specific file
		 * @return 		
		 * 				- pointer to reallocated memory area
		 * 				- NULL if out of ressources
		 */ 
		void * (*reallocate) (allocator_t *this,void * old, size_t bytes, char * file, int line);
		
		/**
		 * Clones memory with LEAK_DETECTION and returns a cloned data area.
		 * 
		 * @warning 		Use this function not directly, only with assigned macro 
		 * 				#allocator_clone_bytes.
		 * 
		 * @param this 	allocator_t object
		 * @param old 	pointer to the old data area
		 * @param bytes number of bytes to allocate
		 * @param file 	filename from which the memory is allocated
		 * @param line 	line number in specific file
		 * @return 		
		 * 				- pointer to reallocated memory area if successful
		 * 				- NULL if out of ressources
		 */ 
		void * (*clone_bytes) (allocator_t *this,void * to_clone, size_t bytes, char * file, int line);		
				
		/**
		 * Frees memory with LEAK_DETECTION.
		 * 
		 * @warning 		Use this function not directly, only with assigned macro 
		 * 				#allocator_free.
		 * 
		 * @param this 		allocator_t object
		 * @param pointer 	pointer to the data area to free
		 */ 
		void (*free_pointer) (allocator_t *this,void * pointer);
		
		/**
		 * Report memory leaks to stderr.
		 *
		 * @warning 		Use this function not directly, only with assigned macro 
		 * 				#report_memory_leaks
		 * 
 		 * @param this 		allocator_t object
		 */
		void (*report_memory_leaks) (allocator_t *this);
	};

		
	/**
	 * @brief Global allocater_t object.
	 * 
	 * Only accessed over macros.
	 */
	extern allocator_t *global_allocator;

	
	/**
	 * Macro to allocate some memory.
	 * 
	 * See #allocator_t.allocate for description.
	 * 
	 * @ingroup utils
	 */
	#define allocator_alloc(bytes) (global_allocator->allocate(global_allocator,bytes,__FILE__,__LINE__))
	
	/**
	 * Macro to allocate some memory for a chunk_t.
	 * 
	 * See #allocator_t.allocate_as_chunk for description.
	 * 
	 * @ingroup utils
	 */
	#define allocator_alloc_as_chunk(bytes) (global_allocator->allocate_as_chunk(global_allocator,bytes,__FILE__,__LINE__))
	
	/**
	 * Macro to reallocate some memory.
	 * 
	 * See #allocator_t.reallocate for description.
	 * 
	 * @ingroup utils
	 */
	#define allocator_realloc(old,bytes) (global_allocator->reallocate(global_allocator,old,bytes,__FILE__, __LINE__))
	
	/**
	 * Macro to clone some memory.
	 * 
	 * See #allocator_t.*clone_bytes  for description.
	 * 
	 * @ingroup utils
	 */
	#define allocator_clone_bytes(old,bytes) (global_allocator->clone_bytes(global_allocator,old,bytes,__FILE__, __LINE__))
	
	/**
	 * Macro to free some memory.
	 * 
	 * See #allocator_t.free_pointer for description.
	 *
	 * @ingroup utils
	 */
	#define allocator_free(pointer) (global_allocator->free_pointer(global_allocator,pointer))
	/**
	 * Macro to free a chunk.
	 */
	#define allocator_free_chunk(chunk){	\
		global_allocator->free_pointer(global_allocator,(chunk)->ptr);			\
		(chunk)->ptr = NULL;				\
		(chunk)->len = 0;					\
	}
	/**
	 * Macro to report memory leaks.
	 * 
	 * See #allocator_s.report_memory_leaks for description.
	 * 
	 * @ingroup utils
	 */
	#define report_memory_leaks(void) (global_allocator->report_memory_leaks(global_allocator))
#else
	/**
	 * Macro to allocate some memory.
	 *
	 * @ingroup utils
	 */
	#define allocator_alloc(bytes) (malloc(bytes))	

	/**
	 * Allocate some memory as chunk.
	 * 
	 * @ingroup utils
	 */
	chunk_t allocator_alloc_as_chunk(size_t bytes);

	/**
	 * Reallocate some memory.
	 * 
	 * @ingroup utils
	 */
	void * allocator_realloc(void * old, size_t newsize);
	
	/**
	 * Free allocated memory.
	 * 
	 * @ingroup utils
	 */
	#define allocator_free(pointer) (free(pointer))
	
	/**
	 * Clone bytes.
	 *
	 *
 	 * @param pointer	pointer to read data from
 	 * @param size		number of bytes to clone
	 * 
	 * @ingroup utils
	 */
	void * allocator_clone_bytes(void * pointer, size_t size);
	
	/**
	 * Frees memory used by chunk.
	 * 
	 * @param chunk		pointer of chunk to free
	 * 
	 * @ingroup utils
	 */
	void allocator_free_chunk(chunk_t *chunk);
	
	/**
	 * Report memory leaks.
	 * 
	 * @ingroup utils
	 */
	#define report_memory_leaks(void) {}
#endif

#endif /*ALLOCATOR_H_*/