Add a set of VFP method functions which can do various sanity asserts

for us in a single place.

bin/varnishd/cache/cache_esi_fetch.c

@@ -346,7 +346,6 @@ vfp_esi_bytes(struct busyobj *bo, struct http_conn *htc, ssize_t bytes)
 	vef = bo->vef_priv;
 	CHECK_OBJ_NOTNULL(vef, VEF_MAGIC);
 
-	AZ(bo->fetch_failed);
 	AN(bo->vep);
 	assert(&bo->htc == htc);
 	if (bo->is_gzip && bo->do_gunzip)

bin/varnishd/cache/cache_fetch.c

@@ -72,6 +72,40 @@ FetchError(struct busyobj *bo, const char *error)
 	return(FetchError2(bo, error, NULL));
 }
 
+/*--------------------------------------------------------------------
+ * VFP method functions
+ */
+
+static void
+VFP_Begin(struct busyobj *bo, size_t estimate)
+{
+	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
+	AN(bo->vfp);
+
+	bo->vfp->begin(bo, estimate);
+}
+
+static int
+VFP_Bytes(struct busyobj *bo, struct http_conn *htc, ssize_t sz)
+{
+	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
+	AN(bo->vfp);
+	CHECK_OBJ_NOTNULL(htc, HTTP_CONN_MAGIC);
+	AZ(bo->fetch_failed);
+
+	return (bo->vfp->bytes(bo, htc, sz));
+}
+
+static int
+VFP_End(struct busyobj *bo)
+{
+	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
+	AN(bo->vfp);
+
+	return (bo->vfp->end(bo));
+}
+
+
 /*--------------------------------------------------------------------
  * VFP_NOP
  *
@@ -235,7 +269,7 @@ fetch_straight(struct busyobj *bo, struct http_conn *htc, ssize_t cl)
 	} else if (cl == 0)
 		return (0);
 
-	i = bo->vfp->bytes(bo, htc, cl);
+	i = VFP_Bytes(bo, htc, cl);
 	if (i <= 0)
 		return (FetchError(bo, "straight insufficient bytes"));
 	return (0);
@@ -292,7 +326,7 @@ fetch_chunked(struct busyobj *bo, struct http_conn *htc)
 		if (cl < 0)
 			return (FetchError(bo,"chunked header number syntax"));
 
-		if (cl > 0 && bo->vfp->bytes(bo, htc, cl) <= 0)
+		if (cl > 0 && VFP_Bytes(bo, htc, cl) <= 0)
 			return (-1);
 
 		i = HTC_Read(htc, buf, 1);
@@ -314,7 +348,7 @@ fetch_eof(struct busyobj *bo, struct http_conn *htc)
 	int i;
 
 	assert(bo->body_status == BS_EOF);
-	i = bo->vfp->bytes(bo, htc, SSIZE_MAX);
+	i = VFP_Bytes(bo, htc, SSIZE_MAX);
 	if (i < 0)
 		return (-1);
 	return (0);
@@ -541,24 +575,24 @@ FetchBody(struct worker *wrk, struct busyobj *bo)
 		break;
 	case BS_LENGTH:
 		cl = fetch_number(bo->h_content_length, 10);
-		bo->vfp->begin(bo, cl > 0 ? cl : 0);
+		VFP_Begin(bo, cl > 0 ? cl : 0);
 		cls = fetch_straight(bo, htc, cl);
 		mklen = 1;
-		if (bo->vfp->end(bo))
+		if (VFP_End(bo))
 			cls = -1;
 		break;
 	case BS_CHUNKED:
-		bo->vfp->begin(bo, cl);
+		VFP_Begin(bo, cl);
 		cls = fetch_chunked(bo, htc);
 		mklen = 1;
-		if (bo->vfp->end(bo))
+		if (VFP_End(bo))
 			cls = -1;
 		break;
 	case BS_EOF:
-		bo->vfp->begin(bo, cl);
+		VFP_Begin(bo, cl);
 		cls = fetch_eof(bo, htc);
 		mklen = 1;
-		if (bo->vfp->end(bo))
+		if (VFP_End(bo))
 			cls = -1;
 		break;
 	case BS_ERROR:

bin/varnishd/cache/cache_gzip.c

@@ -448,7 +448,6 @@ vfp_gunzip_bytes(struct busyobj *bo, struct http_conn *htc, ssize_t bytes)
 	const void *dp;
 
 	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
-	AZ(bo->fetch_failed);
 	vg = bo->vgz_rx;
 	CHECK_OBJ_NOTNULL(vg, VGZ_MAGIC);
 	AZ(vg->vz.avail_in);
@@ -526,7 +525,6 @@ vfp_gzip_bytes(struct busyobj *bo, struct http_conn *htc, ssize_t bytes)
 	const void *dp;
 
 	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
-	AZ(bo->fetch_failed);
 	vg = bo->vgz_rx;
 	CHECK_OBJ_NOTNULL(vg, VGZ_MAGIC);
 	AZ(vg->vz.avail_in);
@@ -613,7 +611,6 @@ vfp_testgzip_bytes(struct busyobj *bo, struct http_conn *htc, ssize_t bytes)
 	struct storage *st;
 
 	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
-	AZ(bo->fetch_failed);
 	vg = bo->vgz_rx;
 	CHECK_OBJ_NOTNULL(vg, VGZ_MAGIC);
 	AZ(vg->vz.avail_in);