Make generic functions for OA's in double format.

bin/varnishd/cache/cache.h

@@ -1065,8 +1065,9 @@ void *ObjSetattr(struct objcore *oc, struct dstat *ds, enum obj_attr attr,
     ssize_t len);
 int ObjCopyAttr(struct objcore *ocd, struct objcore *ocs, struct dstat *ds,
     enum obj_attr attr);
-int ObjSetLastModified(struct objcore *oc, struct dstat *ds, double t);
-double ObjGetLastModified(struct objcore *oc, struct dstat *ds);
+
+int ObjSetDouble(struct objcore *, struct dstat *, enum obj_attr, double);
+int ObjGetDouble(struct objcore *, struct dstat *, enum obj_attr, double *);
 
 /* cache_panic.c */
 void PAN_Init(void);

bin/varnishd/cache/cache_fetch.c

@@ -165,10 +165,10 @@ vbf_beresp2obj(struct busyobj *bo)
 	http_CopyHome(hp2);
 
 	if (http_GetHdr(hp, H_Last_Modified, &b))
-		AZ(ObjSetLastModified(bo->fetch_objcore, bo->stats,
+		AZ(ObjSetDouble(bo->fetch_objcore, bo->stats, OA_LASTMODIFIED,
 		    VTIM_parse(b)));
 	else
-		AZ(ObjSetLastModified(bo->fetch_objcore, bo->stats,
+		AZ(ObjSetDouble(bo->fetch_objcore, bo->stats, OA_LASTMODIFIED,
 		    floor(bo->fetch_objcore->exp.t_origin)));
 
 	/* Disassociate the obj from the bo's workspace */

bin/varnishd/cache/cache_obj.c

@@ -307,36 +307,43 @@ ObjGetXID(struct objcore *oc, struct dstat *ds)
 }
 
 /*--------------------------------------------------------------------
- * NB: Copying double <--> uint64_t for endian encoding is unverified
+ * There is no well-defined byteorder for IEEE-754 double and the
+ * correct solution (frexp(3) and manual encoding) is more work
+ * than our (weak) goal of being endian-agnostic requires at this point.
+ * We give it a shot by memcpy'ing doubles over a uint64_t and then
+ * BE encode that.
  */
 
 int
-ObjSetLastModified(struct objcore *oc, struct dstat *ds, double t)
+ObjSetDouble(struct objcore *oc, struct dstat *ds, enum obj_attr a, double t)
 {
 	void *vp;
 	uint64_t u;
 
 	assert(sizeof t == sizeof u);
 	memcpy(&u, &t, sizeof u);
-	vp = ObjSetattr(oc, ds, OA_LASTMODIFIED, sizeof u);
+	vp = ObjSetattr(oc, ds, a, sizeof u);
 	if (vp == NULL)
 		return (-1);
 	vbe64enc(vp, u);
 	return (0);
 }
 
-double
-ObjGetLastModified(struct objcore *oc, struct dstat *ds)
+int
+ObjGetDouble(struct objcore *oc, struct dstat *ds, enum obj_attr a, double *d)
 {
 	void *vp;
 	uint64_t u;
-	double d;
 	ssize_t l;
 
-	vp = ObjGetattr(oc, ds, OA_LASTMODIFIED, &l);
-	AN(vp);
-	assert(l == sizeof u);
-	u = vbe64dec(vp);
-	memcpy(&d, &u, sizeof d);
-	return (d);
+	assert(sizeof *d == sizeof u);
+	vp = ObjGetattr(oc, ds, a, &l);
+	if (vp == NULL)
+		return (-1);
+	if (d != NULL) {
+		assert(l == sizeof u);
+		u = vbe64dec(vp);
+		memcpy(d, &u, sizeof *d);
+	}
+	return (0);
 }

bin/varnishd/cache/cache_rfc2616.c

@@ -355,7 +355,8 @@ RFC2616_Do_Cond(const struct req *req)
 		ims = VTIM_parse(p);
 		if (ims > req->t_req)	/* [RFC2616 14.25] */
 			return (0);
-		lm = ObjGetLastModified(req->objcore, &req->wrk->stats);
+		AZ(ObjGetDouble(req->objcore,  &req->wrk->stats,
+		    OA_LASTMODIFIED, &lm));
 		if (lm > ims)
 			return (0);
 		do_cond = 1;