--- ray/src/hd/holofile.c	1999/02/10 17:09:20	3.37
+++ ray/src/hd/holofile.c	1999/08/05 15:53:09	3.41
@@ -1,4 +1,4 @@
-/* Copyright (c) 1999 Silicon Graphics, Inc. */
+/* Copyright (c) 1999 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ SGI";
@@ -14,9 +14,9 @@ static char SCCSid[] = "$SunId$ SGI";
 
 #ifndef CACHESIZE
 #ifdef BIGMEM
-#define CACHESIZE	32	/* default cache size (Mbytes, 0==inf) */
+#define CACHESIZE	17	/* default cache size (Mbytes, 0==inf) */
 #else
-#define CACHESIZE	12
+#define CACHESIZE	5
 #endif
 #endif
 #ifndef FREEBEAMS
@@ -30,7 +30,7 @@ static char SCCSid[] = "$SunId$ SGI";
 #endif
 #ifndef FF_DEFAULT
 				/* when to free a beam fragment */
-#define FF_DEFAULT	(FF_ALLOC|FF_WRITE|FF_KILL)
+#define FF_DEFAULT	(FF_WRITE|FF_KILL)
 #endif
 #ifndef MINDIRSEL
 				/* minimum directory seek length */
@@ -52,7 +52,7 @@ HOLO	*hdlist[HDMAX+1];	/* holodeck pointers (NULL term
 
 static struct fraglist {
 	short	nlinks;		/* number of holodeck sections using us */
-	short	writerr;	/* write error encountered */
+	short	writable;	/* 0 read-only, <0 write error encountered */
 	int	nfrags;		/* number of known fragments */
 	BEAMI	*fi;		/* fragments, descending file position */
 	long	flen;		/* last known file length */
@@ -61,6 +61,40 @@ static struct fraglist {
 static int	nhdfragls;	/* size of hdfragl array */
 
 
+HOLO *
+hdalloc(hproto)		/* allocate and set holodeck section based on grid */
+HDGRID	*hproto;
+{
+	HOLO	hdhead;
+	register HOLO	*hp;
+	int	n;
+				/* copy grid to temporary header */
+	bcopy((char *)hproto, (char *)&hdhead, sizeof(HDGRID));
+				/* compute grid vectors and sizes */
+	hdcompgrid(&hdhead);
+				/* allocate header with directory */
+	n = sizeof(HOLO)+nbeams(&hdhead)*sizeof(BEAMI);
+	if ((hp = (HOLO *)malloc(n)) == NULL)
+		return(NULL);
+				/* copy header information */
+	copystruct(hp, &hdhead);
+				/* allocate and clear beam list */
+	hp->bl = (BEAM **)malloc((nbeams(hp)+1)*sizeof(BEAM *)+sizeof(BEAM));
+	if (hp->bl == NULL) {
+		free((char *)hp);
+		return(NULL);
+	}
+	bzero((char *)hp->bl, (nbeams(hp)+1)*sizeof(BEAM *)+sizeof(BEAM));
+	hp->bl[0] = (BEAM *)(hp->bl+nbeams(hp)+1);	/* set blglob(hp) */
+	hp->fd = -1;
+	hp->dirty = 0;
+	hp->priv = NULL;
+				/* clear beam directory */
+	bzero((char *)hp->bi, (nbeams(hp)+1)*sizeof(BEAMI));
+	return(hp);		/* all is well */
+}
+
+
 char *
 hdrealloc(ptr, siz, rout)	/* (re)allocate memory, retry then error */
 char	*ptr;
@@ -85,8 +119,9 @@ char	*rout;
 }
 
 
-hdattach(fd)		/* start tracking file fragments for some section */
+hdattach(fd, wr)	/* start tracking file fragments for some section */
 register int	fd;
+int	wr;
 {
 	if (fd >= nhdfragls) {
 		hdfragl = (struct fraglist *)hdrealloc((char *)hdfragl,
@@ -96,6 +131,7 @@ register int	fd;
 		nhdfragls = fd+1;
 	}
 	hdfragl[fd].nlinks++;
+	hdfragl[fd].writable = wr;		/* set writable flag */
 	hdfragl[fd].flen = lseek(fd, 0L, 2);	/* get file length */
 }
 
@@ -123,6 +159,7 @@ HDGRID	*hproto;		/* holodeck section grid */
 {
 	long	rtrunc;
 	long	fpos;
+	int	writable;
 	register HOLO	*hp;
 	register int	n;
 					/* prepare for system errors */
@@ -148,7 +185,14 @@ HDGRID	*hproto;		/* holodeck section grid */
 				error(WARNING, "dirty holodeck section");
 				break;
 			}
-	} else {			/* assume we're creating it */
+						/* check writability */
+		if (fd < nhdfragls && hdfragl[fd].nlinks)
+			writable = hdfragl[fd].writable;
+		else
+			writable = lseek(fd, fpos, 0) == fpos &&
+				write(fd, (char *)hp, sizeof(HDGRID)) ==
+							sizeof(HDGRID);
+	} else {			/* else assume we're creating it */
 		if ((hp = hdalloc(hproto)) == NULL)
 			goto memerr;
 						/* write header and skeleton */
@@ -157,12 +201,13 @@ HDGRID	*hproto;		/* holodeck section grid */
 					sizeof(HDGRID) ||
 				write(fd, (char *)(hp->bi+1), n) != n)
 			error(SYSTEM, "cannot write header to holodeck file");
+		writable = 1;
 	}
 	hp->fd = fd;	
 	hp->dirty = 0;
 	biglob(hp)->fo = fpos + sizeof(HDGRID);
 					/* start tracking fragments */
-	hdattach(fd);
+	hdattach(fd, writable);
 					/* check rays on disk */
 	fpos = hdfilen(fd);
 	biglob(hp)->nrd = rtrunc = 0;
@@ -501,6 +546,8 @@ int	i;
 	DCHECK(hp->fd < 0 | hp->fd >= nhdfragls || !hdfragl[hp->fd].nlinks,
 			CONSISTENCY, "bad file descriptor in hdfreefrag");
 	f = &hdfragl[hp->fd];
+	if (!f->writable)
+		return(0);
 	if (f->nfrags % FRAGBLK == 0) {	/* delete empty remnants */
 		for (j = k = 0; k < f->nfrags; j++, k++) {
 			while (f->fi[k].nrd == 0)
@@ -559,6 +606,7 @@ int	i;
 	biglob(hp)->nrd -= bi->nrd;		/* tell fragment it's free */
 	bi->nrd = 0;
 	bi->fo = 0L;
+	hdmarkdirty(hp, i);			/* assume we'll reallocate */
 	return(1);
 }
 
@@ -621,19 +669,20 @@ hdsyncbeam(hp, i)		/* sync beam in memory with beam on
 register HOLO	*hp;
 register int	i;
 {
+	int	fragfreed;
 	unsigned int4	nrays;
 	unsigned int	n;
 	long	nfo;
 					/* check file status */
-	if (hdfragl[hp->fd].writerr)
-		return(-1);
+	if (hdfragl[hp->fd].writable <= 0)
+		return(hdfragl[hp->fd].writable);
 	DCHECK(i < 1 | i > nbeams(hp),
 			CONSISTENCY, "bad beam index in hdsyncbeam");
 					/* is current fragment OK? */
 	if (hp->bl[i] == NULL || (nrays = hp->bl[i]->nrm) == hp->bi[i].nrd)
 		return(0);
-	if (hdfragflags&FF_WRITE && hp->bi[i].nrd)
-		hdfreefrag(hp, i);	/* relinquish old fragment */
+					/* relinquish old fragment? */
+	fragfreed = hdfragflags&FF_WRITE && hp->bi[i].nrd && hdfreefrag(hp,i);
 	if (nrays) {			/* get and write new fragment */
 		nfo = hdallocfrag(hp->fd, nrays);
 		errno = 0;
@@ -641,7 +690,7 @@ register int	i;
 			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) {
-			hdfragl[hp->fd].writerr++;
+			hdfragl[hp->fd].writable = -1;
 			hdsync(NULL, 0);	/* sync directories */
 			error(SYSTEM, "write error in hdsyncbeam");
 		}
@@ -650,7 +699,8 @@ register int	i;
 		hp->bi[i].fo = 0L;
 	biglob(hp)->nrd += nrays - hp->bi[i].nrd;
 	hp->bi[i].nrd = nrays;
-	hdmarkdirty(hp, i);		/* section directory now out of date */
+	if (!fragfreed)
+		hdmarkdirty(hp, i);		/* need to flag dir. ent. */
 	return(1);
 }
 
@@ -668,7 +718,7 @@ register int	i;
 			nchanged += hdfreebeam(hdlist[i], 0);
 		return(nchanged);
 	}
-	if (hdfragl[hp->fd].writerr)	/* check for file error */
+	if (hdfragl[hp->fd].writable < 0)	/* check for file error */
 		return(0);
 	if (i == 0) {			/* clear entire holodeck */
 		if (blglob(hp)->nrm == 0)
@@ -721,21 +771,22 @@ register int	i;
 				CONSISTENCY, "bad beam count in hdkillbeam");
 		return(nchanged);
 	}
-	DCHECK(i < 1 | i > nbeams(hp),
-			CONSISTENCY, "bad beam index to hdkillbeam");
+	DCHECK(i < 1 | i > nbeams(hp), CONSISTENCY,
+			"bad beam index to hdkillbeam");
+	DCHECK(!hdfragl[hp->fd].writable, CONSISTENCY,
+			"hdkillbeam called on read-only holodeck");
 	if (hp->bl[i] != NULL) {	/* free memory */
 		blglob(hp)->nrm -= nchanged = hp->bl[i]->nrm;
 		free((char *)hp->bl[i]);
+		hp->bl[i] = NULL;
 	} else
 		nchanged = hp->bi[i].nrd;
-	if (hp->bi[i].nrd) {
-		if (hdfragflags&FF_KILL)
-			hdfreefrag(hp, i);
-		biglob(hp)->nrd -= hp->bi[i].nrd;
-		hp->bi[i].nrd = 0;	/* make sure it's gone */
+	if (hp->bi[i].nrd && !(hdfragflags&FF_KILL && hdfreefrag(hp,i))) {
+		biglob(hp)->nrd -= hp->bi[i].nrd;	/* free failed */
+		hp->bi[i].nrd = 0;
 		hp->bi[i].fo = 0L;
+		hdmarkdirty(hp, i);
 	}
-	hp->bl[i] = NULL;
 	return(nchanged);
 }