BestFit2.cc

//#ident	"@(#)BestFit2.cc	2.1	BUA MIRZA	20150528"
/** @file BestFit2.cc
 * De implementatie van BestFit2.
 */

#include "BestFit2.h"


// ----- hulpfuncties -----

/* //////////////////////////////////////////////////////////////////////////////////////////////////// */
void	BestFit2::free(Area *ap)
{
    require(ap != 0);

    for (ALiterator  i = areas.begin() ; i != areas.end() ; )
    {
        Area  *bp = *i;							// match new ap with existing bp ...
        if (cflag)
        {
            check(!ap->overlaps(bp));    		// sanity check
        }

        // Does older area bp match new free area ap?
        if (bp->getBase() == (ap->getBase() + ap->getSize()))
        {
            // Yes, bp matches with ap ...	[ap directly before bp]
            ALiterator  next = areas.erase(i);	// remove bp from the list
            ap->join(bp);						// append area bp to ap (and destroy bp)
            ++mergers;							// update statistics
            areas.insert(next, ap);				// insert ap before next
            return;
        }
        else if (ap->getBase() == (bp->getBase() + bp->getSize()))
        {
            // Yes, ap matches with bp ... [ap directly after bp]
            ALiterator  next = areas.erase(i);	// remove bp from the list
            bp->join(ap);						// append area ap to bp (and destroy ap)
            ++mergers;							// update statistics
            ap = bp;							// now pretend this is the free'd area
            // and compare it with the new 'next item'
            i = next;							// must "revive" the 'i' iterator here
        }
        else if (ap->getBase() < bp->getBase())
        {
            // To keep the list sorted by address ap should go before bp
            areas.insert(i, ap);				// Insert ap before cursor
            return;
        }
        else
        {
            ++i;								// move on to next area in the freelist
        }
    }

    // Found no match
    areas.push_back(ap);	                    // then ap goes at the end
}
/* //////////////////////////////////////////////////////////////////////////////////////////////////// */


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