dynarr_freenodelist.h

#ifndef __dynarr_free_node_list_h__
#define __dynarr_free_node_list_h__

// the struct FreeSegNode will be used multiple times, so we do not want to redefine it
struct FreeSegNode{
	int index;
	struct FreeSegNode* next;
};
typedef struct FreeSegNode FreeSegNode;

// name of variables
#define FREESEG_LIST_NAME			pFreeSegList
#define FREESEG_INVALID_LIST_NAME	pFreeSegInvalidList


#define _FreeSegNodeMalloc() \
	( (struct FreeSegNode*) malloc(sizeof(struct FreeSegNode)) )
// Swaps two 32-bit intergers without using temporary variables
#define	_SEG_ARR_INT_SWAP(var1, var2)	(\
	(var1)	= (FreeSegNode*) (((int) (void*) var1) ^ ((int) (void*) var2) ),	\
	(var2)	= (FreeSegNode*) (((int) (void*) var1) ^ ((int) (void*) var2) ),	\
	(var1)	= (FreeSegNode*) (((int) (void*) var1) ^ ((int) (void*) var2) )	)
// Given two lists A and B, moves the head of A in front of the
// head of B. Head of A must be non-null.
//
// Before:
//		A-->1-2-3-4-5
//		B-->a-b-c-d-e
// After:
//		A-->2-3-4-5
//		B-->1-a-b-c-d-e
//
#define _SEG_ARR_MOVE_LIST_HEAD(listFrom, listTo)	(\
		_SEG_ARR_INT_SWAP( listFrom->next, listTo), \
		_SEG_ARR_INT_SWAP( listFrom, listTo )	\
	)


#define _SEG_ARR_FREE_LIST_ADD_VALIDLIST(value_seg) \
	( ( !FREESEG_LIST_NAME ) \
			?( \
				FREESEG_LIST_NAME = _FreeSegNodeMalloc(), \
				/*assert(FREESEG_LIST_NAME != NULL ),*/ \
				FREESEG_LIST_NAME->next = NULL, \
				FREESEG_LIST_NAME->index = ((value_seg).index) \
			) \
			:( \
				pTempFreeNode1 = _FreeSegNodeMalloc(), \
				/*assert(pTempFreeNode1 != NULL ),*/ \
				pTempFreeNode1->next = FREESEG_LIST_NAME, \
				FREESEG_LIST_NAME = pTempFreeNode1, \
				FREESEG_LIST_NAME->index = ((value_seg).index) \
			)\
	)

// Algorithm:
// If (an invalid node exists) Then
//		move it to the front of valid list
//		set its index as the index of value_seg
// Else
//		Allocate new node in the valid list
//
#define _SEG_ARR_FREE_LIST_ADD(value_seg) (\
	( FREESEG_INVALID_LIST_NAME )	\
	? (	\
		_SEG_ARR_MOVE_LIST_HEAD( FREESEG_INVALID_LIST_NAME, FREESEG_LIST_NAME ), \
		FREESEG_LIST_NAME->index = ((value_seg).index) \
		)	\
	: ( _SEG_ARR_FREE_LIST_ADD_VALIDLIST(value_seg) )	\
	)


#define _SEG_ARR_REMOVE_LIST_HEAD(list) (\
		pTempFreeNode1 = list, \
		list = list->next, \
		FREE_SAFE( pTempFreeNode1 ) )\

// Algorithm:
// If (a valid node exists) Then
//		output its index, and
//		move it to the front of invalid list
// Else
//		output null index
//
#define _SEG_ARR_FREE_LIST_GRAB_INDEX(value_seg)	(\
	( FREESEG_LIST_NAME ) ?(\
		(value_seg).index = FREESEG_LIST_NAME->index, \
		(value_seg).nextIndex = EMPTY_INDEX, \
		_SEG_ARR_MOVE_LIST_HEAD( FREESEG_LIST_NAME, FREESEG_INVALID_LIST_NAME ), \
		(value_seg)	\
	):(\
		( (value_seg) = NULL_SEG ) \
	) )\


#define _SEG_ARR_FREE_LIST_CLEANUP() {\
			while( FREESEG_LIST_NAME ) _SEG_ARR_REMOVE_LIST_HEAD(FREESEG_LIST_NAME); \
					while( FREESEG_INVALID_LIST_NAME ) _SEG_ARR_REMOVE_LIST_HEAD(FREESEG_INVALID_LIST_NAME); \
	} \


#endif