#ifndef __STACK__
#define __STACK__

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

typedef struct block_starter
{
  struct block_starter *prev;
  struct block_starter *next;
} BLOCK_STARTER;

typedef struct stack
{
  BLOCK_STARTER *block_list;
  int index_in_block;
  int items_per_block;
  int item_c;
  size_t item_size;
  BLOCK_STARTER *block_backup;
  int index_backup;
  int item_c_backup;
} STACK;

void stackBackup(STACK *astack);
void stackRecover(STACK *astack);
void *stackPush(STACK *astack);
void *stackPop(STACK *astack);
void freeStack(STACK *astack);
void emptyStack(STACK *astack);
STACK *createStack(int num_items, size_t unit_size);


#endif