Store VSC exposed state per segment

This moves the exposed flag handling to the segment level, rather than the
point level. This enables not having to iterate over each point when there
is no change from the previous.

lib/libvarnishapi/vsc.c

@@ -62,7 +62,6 @@ VTAILQ_HEAD(vsc_sf_head, vsc_sf);
 struct vsc_pt {
 	struct VSC_point	point;
 	char			*name;
-	int			exposed;
 };
 
 struct vsc_seg {
@@ -77,6 +76,7 @@ struct vsc_seg {
 
 	unsigned		npoints;
 	struct vsc_pt		*points;
+	int			exposed;
 };
 
 struct vsc {
@@ -367,26 +367,31 @@ vsc_add_seg(const struct vsc *vsc, struct vsm *vsm, const struct vsm_fantom *fp)
  */
 
 static void
-vsc_expose(const struct vsc *vsc, const struct vsc_seg *sp, int del)
+vsc_expose(const struct vsc *vsc, struct vsc_seg *sp, int del)
 {
 	struct vsc_pt *pp;
 	unsigned u;
+	int expose;
+
+	if (vsc->fnew != NULL && !sp->exposed &&
+	    !del && sp->head->ready == 1)
+		expose = 1;
+	else if (vsc->fdestroy != NULL && sp->exposed &&
+	    (del || sp->head->ready == 2))
+		expose = 0;
+	else
+		return;
 
 	pp = sp->points;
 	for (u = 0; u < sp->npoints; u++, pp++) {
 		if (pp->name == NULL)
 			continue;
-		if (vsc->fdestroy != NULL && pp->exposed &&
-		    (del || sp->head->ready == 2)) {
-			vsc->fdestroy(vsc->priv, &pp->point);
-			pp->exposed = 0;
-		}
-		if (vsc->fnew != NULL && !pp->exposed &&
-		    !del && sp->head->ready == 1) {
+		if (expose)
 			pp->point.priv = vsc->fnew(vsc->priv, &pp->point);
-			pp->exposed = 1;
-		}
+		else
+			vsc->fdestroy(vsc->priv, &pp->point);
 	}
+	sp->exposed = expose;
 }
 
 /*--------------------------------------------------------------------