--- ray/src/hd/holofile.c	1997/11/05 17:28:49	3.5
+++ ray/src/hd/holofile.c	1997/12/12 21:29:34	3.13
@@ -22,8 +22,13 @@ static char SCCSid[] = "$SunId$ SGI";
 #define PCTFREE		20	/* maximum fraction to free (%) */
 #endif
 
-#define MAXFRAG		(128*FRAGBLK)	/* maximum fragments per file */
+/* define MAXFRAG if you want to limit fragment tracking memory */
 
+#ifndef BSD
+#define write	writebuf	/* safe i/o routines */
+#define read	readbuf
+#endif
+
 #define FRAGBLK		64	/* number of fragments to allocate at a time */
 
 int	hdcachesize = CACHESIZE*1024*1024;	/* target cache size (bytes) */
@@ -33,7 +38,8 @@ 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 */
+	short	writerr;	/* write error encountered */
+	int	nfrags;		/* number of known fragments */
 	BEAMI	*fi;		/* fragments, descending file position */
 	long	flen;		/* last known file length */
 } *hdfrag;		/* fragment lists, indexed by file descriptor */
@@ -68,7 +74,7 @@ register int	fd;
 hdrelease(fd)		/* stop tracking file fragments for some section */
 register int	fd;
 {
-	if (fd >= nhdfrags || !hdfrag[fd].nlinks)
+	if (fd < 0 | fd >= nhdfrags || !hdfrag[fd].nlinks)
 		return;
 	if (!--hdfrag[fd].nlinks && hdfrag[fd].nfrags) {
 		free((char *)hdfrag[fd].fi);
@@ -78,6 +84,21 @@ register int	fd;
 }
 
 
+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 */
@@ -102,6 +123,9 @@ 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;
@@ -115,17 +139,23 @@ 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:
@@ -134,18 +164,23 @@ 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)
@@ -188,6 +223,25 @@ int	all;			/* include overhead (painful) */
 
 
 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 */
@@ -293,21 +347,30 @@ register int	i;
 
 
 int
-hdgetbi(hp, i)			/* allocate a file fragment */
+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);
-
+					/* 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 = (nfo=hp->bi[i].fo) + nrays*sizeof(RAYVAL);
 
 	else {						/* general case */
 		register struct fragment	*f = &hdfrag[hp->fd];
@@ -328,7 +391,7 @@ register int	i;
 						(j+FRAGBLK)*sizeof(BEAMI));
 				if (f->fi == NULL)
 					error(SYSTEM,
-						"out of memory in hdgetbi");
+						"out of memory in hdsyncbeam");
 			}
 			for ( ; ; j--) {	/* insert in descending list */
 				if (!j || hp->bi[i].fo < f->fi[j-1].fo) {
@@ -353,16 +416,16 @@ register int	i;
 			f->nfrags = j;
 		}
 		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))
 				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;
+			nfo = f->fi[k].fo;
 			if (f->fi[k].nrd == nrays) {	/* delete fragment */
 				f->nfrags--;
 				for (j = k; j < f->nfrags; j++)
@@ -373,9 +436,21 @@ register int	i;
 			}
 		}
 	}
+	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);
 }
 
@@ -385,7 +460,7 @@ 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;
@@ -393,27 +468,25 @@ 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;
@@ -421,6 +494,49 @@ register int	i;
 }
 
 
+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);
+}
+
+
 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 */
@@ -434,7 +550,7 @@ register HOLO	*hp;			/* section we're adding from */
 		;
 	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 */
@@ -481,7 +597,7 @@ register HOLO	*honly;			/* NULL means check all */
 		if ((freetarget -= hp[i]->bi[bn[i]].nrd) <= 0)
 			break;
 	}
-	hdsync(honly);		/* synchronize directories as necessary */
+	hdsync(honly, 0);	/* synchronize directories as necessary */
 }