/*
 * Nabil Fadili
 * TCSS 333A
 * March 3 2014
 */

#include <stdio.h>
#include <stdlib.h>
#include "mallok.h"


static memBlock *mainBlock;
static memBlock *front;
static int totalBlocks = 0;										//counter for memBlocks not including mainBlock

void create_pool(int size) {
	mainBlock = malloc(size);
	mainBlock->start = mainBlock;
	mainBlock->size = size;
	mainBlock->free = TRUE;
	mainBlock->next = NULL;
	mainBlock->prev = NULL;
	front = mainBlock;
}

void *my_malloc(int size) {
	memBlock ptr = front;
	while(!ptr->free) {
		ptr = ptr->next;
	}
	//if (ptr->)
	if (size > mainBlock->size) {
		printf("Not enough memory to allocate.\n");
		return NULL;
	}
	if (size <= mainBlock->size) {								//greater than OR equal. keep an eye on this
		memBlock *newBlock = malloc(sizeof(memBlock));

		newBlock->start = mainBlock->start;
		mainBlock->start += size;

		mainBlock->size -= size;

		newBlock->size = size;
		newBlock->free = FALSE;

		newBlock->next = mainBlock;
		newBlock->prev = NULL;
		mainBlock->prev = newBlock;

		totalBlocks++;											//increment count of used blocks

		printf("Memory allocated. Bytes left = %d\n", mainBlock->size);
		printf("Total blocks = %d\n", totalBlocks);

		front = newBlock;

		return newBlock;
	}
	//return NULL;
}
void my_free(void *block) {
	memBlock *freeBlock = block;
	int flag = FALSE;

	freeBlock->free = TRUE;

	if (freeBlock->prev->free) {
		freeBlock->prev->size += freeBlock->size;
		freeBlock->prev->next = freeBlock->next;
		freeBlock->next->prev = freeBlock->prev;
		flag = TRUE;
	}
	if (freeBlock->next->free) {
		if (flag) {
			freeBlock->prev->size += freeBlock->next->size;
			freeBlock->prev->next = freeBlock->next->next;
			freeBlock->next->next->prev = freeBlock->prev;
		}
		else {
			freeBlock->size += freeBlock->next->size;
			freeBlock->next = freeBlock->next->next;
			freeBlock->next->prev = freeBlock;
		}
	}
}