dmmlib/LeaHeader.c

#include "LeaHeader.h"

//returns a pointer to the header of the block	
leaHdr *getHeader(const char * ptr) {
	return (leaHdr *) (ptr - HDR_SIZE);
}

size_t getSize (void *ptr) {
	return (getHeader(ptr)->size >> 1);
}

size_t getPrevSize (void *ptr) {
	size_t sz = getHeader(ptr)->prevSize;
	return sz >> 1;
}

void *getNext(void *ptr) {
	return (void *)((char *) ptr + HDR_SIZE + getSize(ptr));
}

void setSize(void *ptr, size_t sz) {
	size_t size = getSize(ptr);
	size = ((size & 1) | (sz << 1));
	getHeader(ptr)->size = size;
}

void setPrevSize (void *ptr, size_t sz) {
	size_t prevSize = getHeader(ptr)->prevSize;
	prevSize = (prevSize & 1) | (sz << 1);
	getHeader(ptr)->prevSize = prevSize;
}

void markPrevFree (char * ptr) {
	getHeader(ptr)->prevSize &= (size_t) (~ 1);
}

void markPrevInUse (char * ptr) {
	getHeader(ptr)->prevSize |= 1;
}

size_t isPrevFree (char * ptr) {
	size_t free = ~(getHeader(ptr)->prevSize & 1);
	return (free & 1) ;
}

void markInUse (char * ptr) {
	markPrevInUse(getNext(ptr));
}

void markFree (char * ptr) {
	markPrevFree(getNext(ptr));
}
	

size_t isFree (char * ptr) {
	return isPrevFree(getNext(ptr));
}