/**
 * @file allocator.c
 * 
 * @brief Memory allocation with LEAK_DETECTION support
 * 
 * Thread-save implementation 
 */

/*
 * 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 <stddef.h>


/**
 * Function to allocate a special type
 * 
 * @param thing object on it a sizeof is performed
 */
#define allocator_alloc_thing(thing) (allocator_alloc(sizeof(thing)))

#ifdef LEAK_DETECTIVE

	typedef struct allocator_s allocator_t;
	
	struct allocator_s {
	
		/**
		 * 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 allocated memory area
		 */ 
		void * (*allocate) (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 reallocated memory area
		 */ 
		void * (*reallocate) (allocator_t *this,void * old, 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);
	};

	#ifndef ALLOCATOR_C_
		extern allocator_t *global_allocator;
	#endif
	
	#define allocator_alloc(bytes) (global_allocator->allocate(global_allocator,bytes,__FILE__,__LINE__))
	#define allocator_realloc(old,bytes) (global_allocator->reallocate(global_allocator,old,bytes,__FILE__, __LINE__))
	#define allocator_free(pointer) (global_allocator->free_pointer(global_allocator,pointer))
	#define allocator_free_chunk(chunk){	\
		global_allocator->free_pointer(global_allocator,chunk.ptr);			\
		chunk.ptr = NULL;				\
		chunk.len = 0;					\
	}
	#define report_memory_leaks(void) global_allocator->report_memory_leaks(global_allocator);
#else
	#define allocator_alloc(bytes) (malloc(bytes))
	#define allocator_realloc(old,bytes) (realloc(old,bytes))
	#define allocator_free(pointer) (free(pointer))
	#define allocator_free_chunk(chunk){	\
		free(chunk.ptr);					\
		chunk.ptr = NULL;				\
		chunk.len = 0;					\
	}
	#define report_memory_leaks(void) {}
#endif

#endif /*ALLOCATOR_H_*/