id_mm.c

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		startseg = lastscan->start + lastscan->length;

		while (scan != endscan)
		{
			if (scan->start - startseg >= needed)
			{
			//
			// got enough space between the end of lastscan and
			// the start of scan, so throw out anything in the middle
			// and allocate the new block
			//
				purge = lastscan->next;
				lastscan->next = mmnew;
				mmnew->start = *(unsigned *)baseptr = startseg;
				mmnew->next = scan;
				while ( purge != scan)
				{	// free the purgable block
					next = purge->next;
					FREEBLOCK(purge);
					purge = next;		// purge another if not at scan
				}
				mmrover = mmnew;
				return;	// good allocation!
			}

			//
			// if this block is purge level zero or locked, skip past it
			//
			if ( (scan->attributes & LOCKBIT)
				|| !(scan->attributes & PURGEBITS) )
			{
				lastscan = scan;
				startseg = lastscan->start + lastscan->length;
			}


			scan=scan->next;		// look at next line
		}
	}

	if (bombonerror)
	{

extern char configname[];
extern	boolean	insetupscaling;
extern	int	viewsize;
boolean SetViewSize (unsigned width, unsigned height);
#define HEIGHTRATIO		0.50
//
// wolf hack -- size the view down
//
		if (!insetupscaling && viewsize>10)
		{
mmblocktype	far *savedmmnew;
			savedmmnew = mmnew;
			viewsize -= 2;
			SetViewSize (viewsize*16,viewsize*16*HEIGHTRATIO);
			mmnew = savedmmnew;
			goto tryagain;
		}

//		unlink(configname);
		Quit ("MM_GetPtr: Out of memory!");
	}
	else
		mmerror = true;
}

//==========================================================================

/*
====================
=
= MM_FreePtr
=
= Deallocates an unlocked, purgable block
=
====================
*/

void MM_FreePtr (memptr *baseptr)
{
	mmblocktype far *scan,far *last;

	last = mmhead;
	scan = last->next;

	if (baseptr == mmrover->useptr)	// removed the last allocated block
		mmrover = mmhead;

	while (scan->useptr != baseptr && scan)
	{
		last = scan;
		scan = scan->next;
	}

	if (!scan)
		Quit ("MM_FreePtr: Block not found!");

	last->next = scan->next;

	FREEBLOCK(scan);
}
//==========================================================================

/*
=====================
=
= MM_SetPurge
=
= Sets the purge level for a block (locked blocks cannot be made purgable)
=
=====================
*/

void MM_SetPurge (memptr *baseptr, int purge)
{
	mmblocktype far *start;

	start = mmrover;

	do
	{
		if (mmrover->useptr == baseptr)
			break;

		mmrover = mmrover->next;

		if (!mmrover)
			mmrover = mmhead;
		else if (mmrover == start)
			Quit ("MM_SetPurge: Block not found!");

	} while (1);

	mmrover->attributes &= ~PURGEBITS;
	mmrover->attributes |= purge;
}

//==========================================================================

/*
=====================
=
= MM_SetLock
=
= Locks / unlocks the block
=
=====================
*/

void MM_SetLock (memptr *baseptr, boolean locked)
{
	mmblocktype far *start;

	start = mmrover;

	do
	{
		if (mmrover->useptr == baseptr)
			break;

		mmrover = mmrover->next;

		if (!mmrover)
			mmrover = mmhead;
		else if (mmrover == start)
			Quit ("MM_SetLock: Block not found!");

	} while (1);

	mmrover->attributes &= ~LOCKBIT;
	mmrover->attributes |= locked*LOCKBIT;
}

//==========================================================================

/*
=====================
=
= MM_SortMem
=
= Throws out all purgable stuff and compresses movable blocks
=
=====================
*/

void MM_SortMem (void)
{
	mmblocktype far *scan,far *last,far *next;
	unsigned	start,length,source,dest;
	int			playing;

	//
	// lock down a currently playing sound
	//
	playing = SD_SoundPlaying ();
	if (playing)
	{
		switch (SoundMode)
		{
		case sdm_PC:
			playing += STARTPCSOUNDS;
			break;
		case sdm_AdLib:
			playing += STARTADLIBSOUNDS;
			break;
		}
		MM_SetLock(&(memptr)audiosegs[playing],true);
	}


	SD_StopSound();

	if (beforesort)
		beforesort();

	scan = mmhead;

	last = NULL;		// shut up compiler warning

	while (scan)
	{
		if (scan->attributes & LOCKBIT)
		{
		//
		// block is locked, so try to pile later blocks right after it
		//
			start = scan->start + scan->length;
		}
		else
		{
			if (scan->attributes & PURGEBITS)
			{
			//
			// throw out the purgable block
			//
				next = scan->next;
				FREEBLOCK(scan);
				last->next = next;
				scan = next;
				continue;
			}
			else
			{
			//
			// push the non purgable block on top of the last moved block
			//
				if (scan->start != start)
				{
					length = scan->length;
					source = scan->start;
					dest = start;
					while (length > 0xf00)
					{
						movedata(source,0,dest,0,0xf00*16);
						length -= 0xf00;
						source += 0xf00;
						dest += 0xf00;
					}
					movedata(source,0,dest,0,length*16);

					scan->start = start;
					*(unsigned *)scan->useptr = start;
				}
				start = scan->start + scan->length;
			}
		}

		last = scan;
		scan = scan->next;		// go to next block
	}

	mmrover = mmhead;

	if (aftersort)
		aftersort();

	if (playing)
		MM_SetLock(&(memptr)audiosegs[playing],false);
}


//==========================================================================

/*
=====================
=
= MM_ShowMemory
=
=====================
*/

void MM_ShowMemory (void)
{
	mmblocktype far *scan;
	unsigned color,temp,x,y;
	long	end,owner;
	char    scratch[80],str[10];

	temp = bufferofs;
	bufferofs = displayofs;
	scan = mmhead;

	end = -1;

	while (scan)
	{
		if (scan->attributes & PURGEBITS)
			color = 5;		// dark purple = purgable
		else
			color = 9;		// medium blue = non purgable
		if (scan->attributes & LOCKBIT)
			color = 12;		// red = locked
		if (scan->start<=end)
			Quit ("MM_ShowMemory: Memory block order currupted!");
		end = scan->length-1;
		y = scan->start/320;
		x = scan->start%320;
		VW_Hlin(x,x+end,y,color);
		VW_Plot(x,y,15);
		if (scan->next && scan->next->start > end+1)
			VW_Hlin(x+end+1,x+(scan->next->start-scan->start),y,0);	// black = free

		scan = scan->next;
	}

	VW_FadeIn ();
	IN_Ack();

	bufferofs = temp;
}

//==========================================================================

/*
=====================
=
= MM_DumpData
=
=====================
*/

void MM_DumpData (void)
{
	mmblocktype far *scan,far *best;
	long	lowest,oldlowest;
	unsigned	owner;
	char	lock,purge;
	FILE	*dumpfile;


	free (nearheap);
	dumpfile = fopen ("MMDUMP.TXT","w");
	if (!dumpfile)
		Quit ("MM_DumpData: Couldn't open MMDUMP.TXT!");

	lowest = -1;
	do
	{
		oldlowest = lowest;
		lowest = 0xffff;

		scan = mmhead;
		while (scan)
		{
			owner = (unsigned)scan->useptr;

			if (owner && owner<lowest && owner > oldlowest)
			{
				best = scan;
				lowest = owner;
			}

			scan = scan->next;
		}

		if (lowest != 0xffff)
		{
			if (best->attributes & PURGEBITS)
				purge = 'P';
			else
				purge = '-';
			if (best->attributes & LOCKBIT)
				lock = 'L';
			else
				lock = '-';
			fprintf (dumpfile,"0x%p (%c%c) = %u\n"
			,(unsigned)lowest,lock,purge,best->length);
		}

	} while (lowest != 0xffff);

	fclose (dumpfile);
	Quit ("MMDUMP.TXT created.");
}

//==========================================================================


/*
======================
=
= MM_UnusedMemory
=
= Returns the total free space without purging
=
======================
*/

long MM_UnusedMemory (void)
{
	unsigned free;
	mmblocktype far *scan;

	free = 0;
	scan = mmhead;

	while (scan->next)
	{
		free += scan->next->start - (scan->start + scan->length);
		scan = scan->next;
	}

	return free*16l;
}

//==========================================================================


/*
======================
=
= MM_TotalFree
=
= Returns the total free space with purging
=
======================
*/

long MM_TotalFree (void)
{
	unsigned free;
	mmblocktype far *scan;

	free = 0;
	scan = mmhead;

	while (scan->next)
	{
		if ((scan->attributes&PURGEBITS) && !(scan->attributes&LOCKBIT))
			free += scan->length;
		free += scan->next->start - (scan->start + scan->length);
		scan = scan->next;
	}

	return free*16l;
}

//==========================================================================

/*
=====================
=
= MM_BombOnError
=
=====================
*/

void MM_BombOnError (boolean bomb)
{
	bombonerror = bomb;
}