--- ray/src/hd/holofile.c	1997/10/31 15:48:32	3.2
+++ ray/src/hd/holofile.c	1997/12/29 15:17:45	3.15
@@ -16,45 +16,56 @@ static char SCCSid[] = "$SunId$ SGI";
 #define CACHESIZE	16	/* default cache size (Mbytes, 0==inf) */
 #endif
 #ifndef FREEBEAMS
-#define FREEBEAMS	1024	/* maximum beams to free at a time */
+#define FREEBEAMS	512	/* maximum beams to free at a time */
 #endif
 #ifndef PCTFREE
-#define PCTFREE		12	/* maximum fraction to free (%) */
+#define PCTFREE		20	/* maximum fraction to free (%) */
 #endif
-#ifndef FFDMAX
-#define FFDMAX		64	/* max. file descriptor for tracking */
-#endif
 #ifndef MAXFRAG
-#define MAXFRAG		2048	/* maximum fragments tracked in each file */
+#define MAXFRAG		131000	/* maximum fragments/file to track (0==inf) */
 #endif
 
-int	hdcachesize = CACHESIZE*1024*1024;	/* target cache size (bytes) */
+#ifndef BSD
+#define write	writebuf	/* safe i/o routines */
+#define read	readbuf
+#endif
+
+#define FRAGBLK		64	/* number of fragments to allocate at a time */
+
+unsigned	hdcachesize = CACHESIZE*1024*1024;	/* target cache size */
 unsigned long	hdclock;	/* clock value */
 
 HOLO	*hdlist[HDMAX+1];	/* holodeck pointers (NULL term.) */
 
 static struct fragment {
 	short	nlinks;		/* number of holodeck sections using us */
-	short	nfrags;		/* number of known fragments */
-	BEAMI	fi[MAXFRAG];	/* fragments, descending file position */
+	short	writerr;	/* write error encountered */
+	int	nfrags;		/* number of known fragments */
+	BEAMI	*fi;		/* fragments, descending file position */
 	long	flen;		/* last known file length */
-} *hdfrag[FFDMAX];	/* fragment lists, indexed by file descriptor */
+} *hdfrag;		/* fragment lists, indexed by file descriptor */
 
+static int	nhdfrags;	/* size of hdfrag array */
 
+
 hdattach(fd)		/* start tracking file fragments for some section */
 register int	fd;
 {
-	if (fd >= FFDMAX)
-		return;				/* descriptor out of range */
-	if (hdfrag[fd] == NULL) {
-		if ((hdfrag[fd] = (struct fragment *)
-				malloc(sizeof(struct fragment))) == NULL)
-			return;			/* should flag error? */
-		hdfrag[fd]->nlinks = 0;
-		hdfrag[fd]->nfrags = 0;
+	if (fd >= nhdfrags) {
+		if (nhdfrags)
+			hdfrag = (struct fragment *)realloc((char *)hdfrag,
+					(fd+1)*sizeof(struct fragment));
+		else
+			hdfrag = (struct fragment *)malloc(
+					(fd+1)*sizeof(struct fragment));
+		if (hdfrag == NULL)
+			error(SYSTEM, "out of memory in hdattach");
+		bzero((char *)(hdfrag+nhdfrags),
+				(fd+1-nhdfrags)*sizeof(struct fragment));
+		nhdfrags = fd+1;
 	}
-	hdfrag[fd]->nlinks++;
-	hdfrag[fd]->flen = lseek(fd, 0L, 2);	/* get file length */
+	hdfrag[fd].nlinks++;
+	hdfrag[fd].flen = lseek(fd, 0L, 2);	/* get file length */
 }
 
 
@@ -64,15 +75,31 @@ register int	fd;
 hdrelease(fd)		/* stop tracking file fragments for some section */
 register int	fd;
 {
-	if (fd >= FFDMAX || hdfrag[fd] == NULL)
+	if (fd < 0 | fd >= nhdfrags || !hdfrag[fd].nlinks)
 		return;
-	if (!--hdfrag[fd]->nlinks) {
-		free((char *)hdfrag[fd]);
-		hdfrag[fd] = NULL;
+	if (!--hdfrag[fd].nlinks && hdfrag[fd].nfrags) {
+		free((char *)hdfrag[fd].fi);
+		hdfrag[fd].fi = NULL;
+		hdfrag[fd].nfrags = 0;
 	}
 }
 
 
+markdirty(hp)			/* mark holodeck section directory dirty */
+register HOLO	*hp;
+{
+	static BEAMI	smudge = {0, -1};
+
+	if (hp->dirty)		/* already marked? */
+		return;
+	hp->dirty = 1;
+	if (lseek(hp->fd, biglob(hp)->fo+(nbeams(hp)-1)*sizeof(BEAMI), 0) < 0
+			|| write(hp->fd, (char *)&smudge,
+					sizeof(BEAMI)) != sizeof(BEAMI))
+		error(SYSTEM, "seek/write error in markdirty");
+}
+
+
 HOLO *
 hdinit(fd, hproto)	/* initialize a holodeck section in a file */
 int	fd;			/* corresponding file descriptor */
@@ -97,6 +124,9 @@ HDGRID	*hproto;		/* holodeck section grid */
 		n = nbeams(hp)*sizeof(BEAMI);
 		if (read(fd, (char *)(hp->bi+1), n) != n)
 			error(SYSTEM, "failure loading holodeck directory");
+						/* check that it's clean */
+		if (hp->bi[nbeams(hp)].fo < 0)
+			error(USER, "dirty holodeck section");
 	} else {			/* assume we're creating it */
 		if ((hp = hdalloc(hproto)) == NULL)
 			goto memerr;
@@ -110,17 +140,23 @@ HDGRID	*hproto;		/* holodeck section grid */
 	hp->fd = fd;	
 	hp->dirty = 0;
 	biglob(hp)->fo = fpos + sizeof(HDGRID);
-	biglob(hp)->nrd = 0;		/* count rays on disk */
-	for (n = nbeams(hp); n > 0; n--)
-		biglob(hp)->nrd += hp->bi[n].nrd;
+					/* start tracking fragments */
+	hdattach(fd);
+					/* check rays on disk */
+	fpos = hdfilen(fd);
+	biglob(hp)->nrd = 0;
+	for (n = hproto == NULL ? nbeams(hp) : 0; n > 0; n--)
+		if (hp->bi[n].nrd)
+			if (hp->bi[n].fo + hp->bi[n].nrd > fpos)
+				hp->bi[n].nrd = 0;	/* off end */
+			else
+				biglob(hp)->nrd += hp->bi[n].nrd;
 					/* add to holodeck list */
 	for (n = 0; n < HDMAX; n++)
 		if (hdlist[n] == NULL) {
 			hdlist[n] = hp;
 			break;
 		}
-					/* start tracking fragments (last) */
-	hdattach(fd);
 					/* all done */
 	return(hp);
 memerr:
@@ -129,19 +165,25 @@ memerr:
 
 
 int
-hdsync(hp)			/* update directory on disk if necessary */
+hdsync(hp, all)			/* update beams and directory on disk */
 register HOLO	*hp;
+int	all;
 {
 	register int	j, n;
 
-	if (hp == NULL) {		/* do all */
+	if (hp == NULL) {		/* do all holodecks */
 		n = 0;
 		for (j = 0; hdlist[j] != NULL; j++)
-			n += hdsync(hdlist[j]);
+			n += hdsync(hdlist[j], all);
 		return(n);
 	}
-	if (!hp->dirty)			/* check first */
+					/* sync the beams */
+	for (j = (all ? nbeams(hp) : 0); j > 0; j--)
+		if (hp->bl[j] != NULL)
+			hdsyncbeam(hp, j);
+	if (!hp->dirty)			/* directory clean? */
 		return(0);
+	errno = 0;
 	if (lseek(hp->fd, biglob(hp)->fo, 0) < 0)
 		error(SYSTEM, "cannot seek on holodeck file");
 	n = nbeams(hp)*sizeof(BEAMI);
@@ -152,7 +194,7 @@ register HOLO	*hp;
 }
 
 
-long
+unsigned
 hdmemuse(all)		/* return memory usage (in bytes) */
 int	all;			/* include overhead (painful) */
 {
@@ -171,14 +213,36 @@ int	all;			/* include overhead (painful) */
 		}
 	}
 	if (all)
-		for (j = 0; j < FFDMAX; j++)
-			if (hdfrag[j] != NULL)
-				total += sizeof(struct fragment);
+		for (j = 0; j < nhdfrags; j++) {
+			total += sizeof(struct fragment);
+			if (hdfrag[j].nfrags)
+				total += FRAGBLK*sizeof(BEAMI) *
+					((hdfrag[j].nfrags-1)/FRAGBLK + 1) ;
+		}
 	return(total);
 }
 
 
 long
+hdfilen(fd)		/* return file length for fd */
+int	fd;
+{
+	long	fpos, flen;
+
+	if (fd < 0)
+		return(-1);
+	if (fd >= nhdfrags || !hdfrag[fd].nlinks) {
+		if ((fpos = lseek(fd, 0L, 1)) < 0)
+			return(-1);
+		flen = lseek(fd, 0L, 2);
+		lseek(fd, fpos, 0);
+		return(flen);
+	}
+	return(hdfrag[fd].flen);
+}
+
+
+long
 hdfiluse(fd, all)	/* compute file usage (in bytes) */
 int	fd;			/* open file descriptor to check */
 int	all;			/* include overhead and unflushed data */
@@ -221,6 +285,7 @@ int	nr;			/* number of new rays desired */
 		hp->bl[i]->tick = hdclock;	/* preempt swap */
 	if (hdcachesize > 0 && hdmemuse(0) >= hdcachesize)
 		hdfreecache(PCTFREE, NULL);	/* free some space */
+	errno = 0;
 	if (hp->bl[i] == NULL) {		/* allocate (and load) */
 		n = hp->bi[i].nrd + nr;
 		if ((hp->bl[i] = (BEAM *)malloc(hdbsiz(n))) == NULL)
@@ -244,8 +309,8 @@ int	nr;			/* number of new rays desired */
 	p = hdbray(hp->bl[i]) + hp->bl[i]->nrm;
 	hp->bl[i]->nrm += nr;			/* update in-core structure */
 	bzero((char *)p, nr*sizeof(RAYVAL));
-	hp->bl[i]->tick = ++hdclock;		/* update LRU clock */
-	blglob(hp)->tick = hdclock;
+	hp->bl[i]->tick = hdclock;		/* update LRU clock */
+	blglob(hp)->tick = hdclock++;
 	return(p);				/* point to new rays */
 memerr:
 	error(SYSTEM, "out of memory in hdnewrays");
@@ -276,80 +341,173 @@ register int	i;
 		if (read(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
 			error(SYSTEM, "error reading beam from holodeck file");
 	}
-	hp->bl[i]->tick = ++hdclock;	/* update LRU clock */
-	blglob(hp)->tick = hdclock;
+	hp->bl[i]->tick = hdclock;	/* update LRU clock */
+	blglob(hp)->tick = hdclock++;
 	return(hp->bl[i]);
 }
 
 
 int
-hdgetbi(hp, i)			/* allocate a file fragment */
+hdfilord(hb1, hb2)	/* order beams for optimal loading */
+register HDBEAMI	*hb1, *hb2;
+{
+	register int	c;
+				/* sort by file descriptor first */
+	if ((c = hb1->h->fd - hb2->h->fd))
+		return(c);
+				/* then by position in file */
+	return(hb1->h->bi[hb1->b].fo - hb2->h->bi[hb2->b].fo);
+}
+
+
+hdloadbeams(hb, n, bf)	/* load a list of beams in optimal order */
+register HDBEAMI	*hb;	/* list gets sorted by hdfilord() */
+int	n;			/* list length */
+int	(*bf)();		/* callback function (optional) */
+{
+	unsigned	origcachesize, memuse;
+	register BEAM	*bp;
+	int	bytesloaded, needbytes, bytes2free;
+	register int	i;
+					/* precheck consistency */
+	for (i = n; i--; )
+		if (hb[i].h == NULL || hb[i].b < 1 | hb[i].b > nbeams(hb[i].h))
+			error(CONSISTENCY, "bad beam in hdloadbeams");
+					/* sort list for optimal access */
+	qsort((char *)hb, n, sizeof(HDBEAMI), hdfilord);
+	bytesloaded = needbytes = 0;	/* figure out memory needs */
+	if ((origcachesize = hdcachesize) > 0) {
+		for (i = n; i--; )
+			if ((bp = hb[i].h->bl[hb[i].b]) != NULL) {
+				bp->tick = hdclock;	/* preempt swap */
+				bytesloaded += bp->nrm;
+			} else				/* prepare to load */
+				needbytes += hb[i].h->bi[hb[i].b].nrd;
+		bytesloaded *= sizeof(RAYVAL);
+		needbytes *= sizeof(RAYVAL);
+		do {				/* free enough memory */
+			memuse = hdmemuse(0);
+			bytes2free = needbytes - (signed)(hdcachesize-memuse);
+			if (bytes2free > (signed)(memuse - bytesloaded))
+				bytes2free = memuse - bytesloaded;
+		} while (bytes2free > 0 &&
+				hdfreecache(100*bytes2free/memuse, NULL) < 0);
+	}
+	hdcachesize = 0;		/* load the ordered beams w/o swap */
+	for (i = 0; i < n; i++)
+		if ((bp = hdgetbeam(hb[i].h, hb[i].b)) != NULL && bf != NULL)
+			(*bf)(bp, hb[i].h, hb[i].b);
+	hdcachesize = origcachesize;	/* resume dynamic swapping */
+}
+
+
+int
+hdsyncbeam(hp, i)		/* sync beam in memory with beam on disk */
 register HOLO	*hp;
 register int	i;
 {
-	int	nrays = hp->bl[i]->nrm;
-
-	if (hp->bi[i].nrd == nrays)	/* current one will do? */
+	unsigned int	nrays;
+	long	nfo;
+	unsigned int	n;
+					/* check file status */
+	if (hdfrag[hp->fd].writerr)
+		return(-1);
+#ifdef DEBUG
+	if (i < 1 | i > nbeams(hp))
+		error(CONSISTENCY, "bad beam index in hdsyncbeam");
+#endif
+					/* is current fragment OK? */
+	if (hp->bl[i] == NULL || (nrays = hp->bl[i]->nrm) == hp->bi[i].nrd)
 		return(0);
-
-	if (hp->fd >= FFDMAX || hdfrag[hp->fd] == NULL)	/* untracked */
+					/* locate fragment */
+	if (hp->fd >= nhdfrags || !hdfrag[hp->fd].nlinks) /* untracked */
 		hp->bi[i].fo = lseek(hp->fd, 0L, 2);
 
 	else if (hp->bi[i].fo + hp->bi[i].nrd*sizeof(RAYVAL) ==
-			hdfrag[hp->fd]->flen)		/* EOF special case */
-		hdfrag[hp->fd]->flen = hp->bi[i].fo + nrays*sizeof(RAYVAL);
+			hdfrag[hp->fd].flen)		/* EOF special case */
+		hdfrag[hp->fd].flen = (nfo=hp->bi[i].fo) + nrays*sizeof(RAYVAL);
 
 	else {						/* general case */
-		register struct fragment	*f = hdfrag[hp->fd];
+		register struct fragment	*f = &hdfrag[hp->fd];
 		register int	j, k;
 					/* relinquish old fragment */
 		if (hp->bi[i].nrd) {
-			if ((j = ++f->nfrags) >= MAXFRAG)
+			j = f->nfrags++;
+#if MAXFRAG
+			if (j >= MAXFRAG-1)
 				f->nfrags--;
-			for ( ; ; ) {	/* stick it in our descending list */
-				if (!--j || hp->bi[i].fo < f->fi[j-1].fo) {
+#endif
+			if (j % FRAGBLK == 0) {		/* more frag. space */
+				if (f->fi == NULL)
+					f->fi = (BEAMI *)malloc(
+							FRAGBLK*sizeof(BEAMI));
+				else
+					f->fi = (BEAMI *)realloc((char *)f->fi,
+						(j+FRAGBLK)*sizeof(BEAMI));
+				if (f->fi == NULL)
+					error(SYSTEM,
+						"out of memory in hdsyncbeam");
+			}
+			for ( ; ; j--) {	/* insert in descending list */
+				if (!j || hp->bi[i].fo < f->fi[j-1].fo) {
 					f->fi[j].fo = hp->bi[i].fo;
 					f->fi[j].nrd = hp->bi[i].nrd;
 					break;
 				}
-				copystruct(f->fi+j, f->fi+j-1);
+				copystruct(f->fi+j, f->fi+(j-1));
 			}
 					/* coalesce adjacent fragments */
-			for (j = k = 0; k < f->nfrags; j++, k++) {
-				if (j != k)
-					copystruct(f->fi+j, f->fi+k);
-				while (k+1 < f->nfrags &&
-				f->fi[k+1].fo + f->fi[k+1].nrd*sizeof(RAYVAL)
-						== f->fi[j].fo)
-					f->fi[j].fo -=
-						f->fi[++k].nrd*sizeof(RAYVAL);
+			if (j && f->fi[j-1].fo == f->fi[j].fo +
+					f->fi[j].nrd*sizeof(RAYVAL)) {
+				f->fi[j].nrd += f->fi[j-1].nrd;
+				f->fi[j-1].nrd = 0;
 			}
-			f->nfrags = j;
+			if (j+1 < f->nfrags && f->fi[j].fo == f->fi[j+1].fo +
+					f->fi[j+1].nrd*sizeof(RAYVAL)) {
+				f->fi[j+1].nrd += f->fi[j].nrd;
+				f->fi[j].nrd = 0;
+			}
 		}
 		k = -1;			/* find closest-sized fragment */
-		for (j = f->nfrags; j-- > 0; )
+		for (j = (nrays ? f->nfrags : 0); j-- > 0; )
 			if (f->fi[j].nrd >= nrays &&
-					(k < 0 || f->fi[j].nrd < f->fi[k].nrd)
-					&& f->fi[k=j].nrd == nrays)
-				break;
+					(k < 0 || f->fi[j].nrd < f->fi[k].nrd))
+				if (f->fi[k=j].nrd == nrays)
+					break;
 		if (k < 0) {		/* no fragment -- extend file */
-			hp->bi[i].fo = f->flen;
+			nfo = f->flen;
 			f->flen += nrays*sizeof(RAYVAL);
 		} else {		/* else use fragment */
-			hp->bi[i].fo = f->fi[k].fo;
-			if (f->fi[k].nrd == nrays) {	/* delete fragment */
-				f->nfrags--;
-				for (j = k; j < f->nfrags; j++)
-					copystruct(f->fi+j, f->fi+j+1);
-			} else {			/* else shrink it */
-				f->fi[k].fo += nrays*sizeof(RAYVAL);
-				f->fi[k].nrd -= nrays;
-			}
+			nfo = f->fi[k].fo;
+			f->fi[k].fo += nrays*sizeof(RAYVAL);
+			f->fi[k].nrd -= nrays;
 		}
+					/* delete empty remnants */
+		for (j = k = 0; k < f->nfrags; j++, k++) {
+			while (f->fi[k].nrd == 0)
+				if (++k >= f->nfrags)
+					goto endloop;
+			if (k > j)
+				copystruct(f->fi+j, f->fi+k);
+		}
+	endloop:
+		f->nfrags = j;
 	}
+	if (nrays) {		/* write the new fragment */
+		errno = 0;
+		if (lseek(hp->fd, nfo, 0) < 0)
+			error(SYSTEM, "cannot seek on holodeck file");
+		n = hp->bl[i]->nrm * sizeof(RAYVAL);
+		if (write(hp->fd, (char *)hdbray(hp->bl[i]), n) != n) {
+			hdfrag[hp->fd].writerr++;
+			hdsync(hp, 0);		/* sync directory */
+			error(SYSTEM, "write error in hdsyncbeam");
+		}
+	}
 	biglob(hp)->nrd += nrays - hp->bi[i].nrd;
 	hp->bi[i].nrd = nrays;
-	hp->dirty++;		/* section directory now out of date */
+	hp->bi[i].fo = nfo;
+	markdirty(hp);		/* section directory now out of date */
 	return(1);
 }
 
@@ -359,7 +517,7 @@ hdfreebeam(hp, i)		/* free beam, writing if dirty */
 register HOLO	*hp;
 register int	i;
 {
-	int	nchanged, n;
+	int	nchanged;
 
 	if (hp == NULL) {		/* clear all holodecks */
 		nchanged = 0;
@@ -367,27 +525,25 @@ register int	i;
 			nchanged += hdfreebeam(hdlist[i], 0);
 		return(nchanged);
 	}
+	if (hdfrag[hp->fd].writerr)	/* check for file error */
+		return(0);
 	if (i == 0) {			/* clear entire holodeck */
 		nchanged = 0;
-		for (i = 1; i <= nbeams(hp); i++)
-			nchanged += hdfreebeam(hp, i);
+		for (i = nbeams(hp); i > 0; i--)
+			if (hp->bl[i] != NULL)
+				nchanged += hdfreebeam(hp, i);
 		return(nchanged);
 	}
+#ifdef DEBUG
 	if (i < 1 | i > nbeams(hp))
 		error(CONSISTENCY, "bad beam index to hdfreebeam");
+#endif
 	if (hp->bl[i] == NULL)
 		return(0);
 					/* check for additions */
 	nchanged = hp->bl[i]->nrm - hp->bi[i].nrd;
-	if (nchanged) {
-		hdgetbi(hp, i);			/* allocate a file position */
-		errno = 0;
-		if (lseek(hp->fd, hp->bi[i].fo, 0) < 0)
-			error(SYSTEM, "cannot seek on holodeck file");
-		n = hp->bl[i]->nrm * sizeof(RAYVAL);
-		if (write(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
-			error(SYSTEM, "write error in hdfreebeam");
-	}
+	if (nchanged)
+		hdsyncbeam(hp, i);		/* write new fragment */
 	blglob(hp)->nrm -= hp->bl[i]->nrm;
 	free((char *)hp->bl[i]);		/* free memory */
 	hp->bl[i] = NULL;
@@ -395,67 +551,111 @@ register int	i;
 }
 
 
-hdlrulist(ha, ba, n, hp)	/* add beams from holodeck to LRU list */
-register HOLO	*ha[];			/* section list (NULL terminated) */
-register int	ba[];			/* beam index to go with section */
-int	n;				/* length of arrays minus 1 */
+int
+hdkillbeam(hp, i)		/* delete beam from holodeck */
+register HOLO	*hp;
+register int	i;
+{
+	static BEAM	emptybeam;
+	int	nchanged;
+
+	if (hp == NULL) {		/* clobber all holodecks */
+		nchanged = 0;
+		for (i = 0; hdlist[i] != NULL; i++)
+			nchanged += hdkillbeam(hdlist[i], 0);
+		return(nchanged);
+	}
+	if (i == 0) {			/* clobber entire holodeck */
+		nchanged = 0;
+		for (i = nbeams(hp); i > 0; i--)
+			if (hp->bi[i].nrd > 0 || hp->bl[i] != NULL)
+				nchanged += hdkillbeam(hp, i);
+#ifdef DEBUG
+		if (biglob(hp)->nrd != 0 | blglob(hp)->nrm != 0)
+			error(CONSISTENCY, "bad beam count in hdkillbeam");
+#endif
+		return(nchanged);
+	}
+#ifdef DEBUG
+	if (i < 1 | i > nbeams(hp))
+		error(CONSISTENCY, "bad beam index to hdkillbeam");
+#endif
+	if (hp->bl[i] != NULL) {	/* free memory */
+		blglob(hp)->nrm -= nchanged = hp->bl[i]->nrm;
+		free((char *)hp->bl[i]);
+	} else
+		nchanged = hp->bi[i].nrd;
+	if (hp->bi[i].nrd) {		/* free file fragment */
+		hp->bl[i] = &emptybeam;
+		hdsyncbeam(hp, i);
+	}
+	hp->bl[i] = NULL;
+	return(nchanged);
+}
+
+
+int
+hdlrulist(hb, nents, n, hp)	/* add beams from holodeck to LRU list */
+register HDBEAMI	*hb;		/* beam list */
+int	nents;				/* current list length */
+int	n;				/* maximum list length */
 register HOLO	*hp;			/* section we're adding from */
 {
 	register int	i, j;
-	int	nents;
-					/* find last entry in LRU list */
-	for (j = 0; ha[j] != NULL; j++)
-		;
-	nents = j;
 					/* insert each beam from hp */
-	for (i = nbeams(hp); i > 0; i-- ) {
+	for (i = nbeams(hp); i > 0; i--) {
 		if (hp->bl[i] == NULL)		/* check if loaded */
 			continue;
-		if ((j = ++nents) > n)		/* grow list if we can */
+#if 0
+		if (hp->bl[i]->tick == hdclock)	/* preempt swap? */
+			continue;
+#endif
+		if ((j = ++nents) >= n)		/* grow list if we can */
 			nents--;
 		for ( ; ; ) {			/* bubble into place */
 			if (!--j || hp->bl[i]->tick >=
-					ha[j-1]->bl[ba[j-1]]->tick) {
-				ha[j] = hp;
-				ba[j] = i;
+					hb[j-1].h->bl[hb[j-1].b]->tick) {
+				hb[j].h = hp;
+				hb[j].b = i;
 				break;
 			}
-			ha[j] = ha[j-1];
-			ba[j] = ba[j-1];
+			copystruct(hb+j, hb+(j-1));
 		}
 	}
-	ha[nents] = NULL;		/* all done */
-	ba[nents] = 0;
+	return(nents);			/* return new list length */
 }
 
 
+int
 hdfreecache(pct, honly)		/* free up cache space, writing changes */
 int	pct;				/* maximum percentage to free */
 register HOLO	*honly;			/* NULL means check all */
 {
-	HOLO	*hp[FREEBEAMS+1];
-	int	bn[FREEBEAMS+1];
+	HDBEAMI	hb[FREEBEAMS];
 	int	freetarget;
+	int	n;
 	register int	i;
 						/* compute free target */
 	freetarget = (honly != NULL) ? blglob(honly)->nrm :
 			hdmemuse(0)/sizeof(RAYVAL) ;
 	freetarget = freetarget*pct/100;
+	if (freetarget <= 0)
+		return(0);
 						/* find least recently used */
-	hp[0] = NULL;
-	bn[0] = 0;
+	n = 0;
 	if (honly != NULL)
-		hdlrulist(hp, bn, FREEBEAMS, honly);
+		n = hdlrulist(hb, n, FREEBEAMS, honly);
 	else
 		for (i = 0; hdlist[i] != NULL; i++)
-			hdlrulist(hp, bn, FREEBEAMS, hdlist[i]);
+			n = hdlrulist(hb, n, FREEBEAMS, hdlist[i]);
 						/* free LRU beams */
-	for (i = 0; hp[i] != NULL; i++) {
-		hdfreebeam(hp[i], bn[i]);
-		if ((freetarget -= hp[i]->bi[bn[i]].nrd) <= 0)
+	for (i = 0; i < n; i++) {
+		hdfreebeam(hb[i].h, hb[i].b);
+		if ((freetarget -= hb[i].h->bi[hb[i].b].nrd) <= 0)
 			break;
 	}
-	hdsync(honly);		/* synchronize directories as necessary */
+	hdsync(honly, 0);	/* synchronize directories as necessary */
+	return(-freetarget);	/* return how far past goal we went */
 }