Update pcre interface for current varnish-cache

XXX NOTE:

as long as we do not have https://github.com/varnishcache/varnish-cache/pull/3724/files
in varnish-cache, we can not use anchored matches

src/tests/wadj_basic.vtc

@@ -41,7 +41,8 @@ varnish v1 -vcl+backend {
 	sub vcl_init {
 	    new foo = weightadjust.random();
 	    foo.add_backend(backend=s1, weight=1,
-			    weight_update = "^X-Weight: ([\d.]+)",
+			    # XXX add back ^X-Weight
+			    weight_update = "X-Weight: ([\d.]+)",
 			    interval = 1h);
 	}
 
@@ -49,7 +50,8 @@ varnish v1 -vcl+backend {
 	    if (req.url == "/1") {
 		vtc.sleep(1s);
 		foo.add_backend(backend=s1_hosthdr, weight=1,
-				weight_update = "^X-Weight: (\d+\.\d+)",
+				# XXX add back ^X-Weight
+				weight_update = "X-Weight: (\d+\.\d+)",
 				interval = 1h);
 		vtc.sleep(1s);
 		foo.remove_backend(backend=s1);
@@ -69,7 +71,8 @@ varnish v1 -vcl+backend {
 GET /weight HTTP/1.1
 Host: weighthost
 "},
-				weight_update = "^X-Weight: ([\d.]+)",
+				# XXX add back ^X-Weight
+				weight_update = "X-Weight: ([\d.]+)",
 				interval = 1h);
 		vtc.sleep(1s);
 		return (synth(200));

src/vmod_weightadjust.c

@@ -135,30 +135,6 @@ vmod_event_function(VRT_CTX, struct vmod_priv *priv, enum vcl_event_e e)
 	return (0);
 }
 
-static vre_t *
-wadj_cfg_re(VRT_CTX, struct vmod_weightadjust_random *rr, VCL_BACKEND be,
-    VCL_STRING weight_update)
-{
-	vre_t *vre;
-	const char *err;
-	int erroff;
-	/*
-	 * using PCRE options here violates the varnish interface abstaction -
-	 * we'd need some more code duplication here if that was a concern
-	 */
-	vre = VRE_compile(weight_update, PCRE_MULTILINE,
-	    &err, &erroff);
-
-	if (vre == NULL) {
-		VERR(ctx, "%s.%s regex errror (%s) for %s pos %d",
-		    rr->vd->dir->vcl_name, be->vcl_name, err,
-		    weight_update, erroff);
-	}
-
-	/* XXX check for one capturing subexpression */
-	return vre;
-}
-
 /* largely taken from vbp_build_req() */
 static char *
 wadj_cfg_req(const struct backend *be, VCL_STRING url, VCL_STRING request,
@@ -242,10 +218,9 @@ vmod_random__fini(struct vmod_weightadjust_random **rrp)
 }
 
 VCL_VOID
-vmod_random_add_backend(VRT_CTX, struct vmod_weightadjust_random *rr,
-    VCL_BACKEND vcl_be, VCL_REAL w, VCL_STRING weight_update, VCL_STRING url,
-    VCL_STRING request, VCL_DURATION timeout, VCL_DURATION interval,
-    VCL_INT buffer)
+vmod_random_add_backend(VRT_CTX,
+    struct VPFX(weightadjust_random) *rr,
+    struct VARGS(random_add_backend) *args)
 {
 	struct vmod_wadj_vcl	*wa_vcl;
 	struct wadj_prop	*prop;
@@ -257,26 +232,26 @@ vmod_random_add_backend(VRT_CTX, struct vmod_weightadjust_random *rr,
 	wa_vcl = rr->extra.wa_vcl;
 	CHECK_OBJ_NOTNULL(wa_vcl, VMOD_WADJ_VCL_MAGIC);
 
-	if (vcl_be->priv == NULL) {
+	if (args->backend->priv == NULL) {
 		ERR(ctx, "can only be used with real backends "
 		    "(no director layering)");
 		return;
 	}
 
-	CAST_OBJ_NOTNULL(be, vcl_be->priv, BACKEND_MAGIC);
+	CAST_OBJ_NOTNULL(be, args->backend->priv, BACKEND_MAGIC);
 
-	if (weight_update == NULL || weight_update[0] == '\0') {
+	if (! args->valid_weight_update) {
 		msg(ctx, "vmod weightadjust director %s "
 		    "add_backend(%s) without weight update falls back "
 		    "to standard behaviour",
-		    rr->vd->dir->vcl_name, vcl_be->vcl_name);
+		    rr->vd->dir->vcl_name, args->backend->vcl_name);
 		goto no_weightadjust;
 	}
 
 	vdir_rdlock(rr->vd);
 	nb = rr->vd->n_backend;
 	for (u = 0; u < nb; u++) {
-		if (rr->vd->backend[u] == vcl_be)
+		if (rr->vd->backend[u] == args->backend)
 			break;
 	}
 	vdir_unlock(rr->vd);
@@ -292,19 +267,18 @@ vmod_random_add_backend(VRT_CTX, struct vmod_weightadjust_random *rr,
 	prop->vd = rr->vd;
 	prop->be = be;
 	prop->vd_updates = &rr->extra.updates;
-	prop->vre = wadj_cfg_re(ctx, rr, vcl_be, weight_update);
-	if (prop->vre == NULL)
-		goto err;
-	prop->req = wadj_cfg_req(be, url, request, &prop->reqlen);
-	if ((prop->timeout = timeout) < 0) {
+	AN(args->weight_update);
+	prop->vre = args->weight_update;
+	prop->req = wadj_cfg_req(be, args->url, args->request, &prop->reqlen);
+	if ((prop->timeout = args->timeout) < 0) {
 		ERR(ctx, "negative timeout");
 		goto err;
 	}
-	if ((prop->interval = interval ) < 0) {
+	if ((prop->interval = args->interval ) < 0) {
 		ERR(ctx, "negative interval");
 		goto err;
 	}
-	if ((prop->bufsz = buffer) < 128) {
+	if ((prop->bufsz = args->buffer) < 128) {
 		ERR(ctx, "buffer too small");
 		goto err;
 	}
@@ -319,7 +293,7 @@ vmod_random_add_backend(VRT_CTX, struct vmod_weightadjust_random *rr,
 	AZ(pthread_mutex_unlock(&wa_vcl->mtx));
 
   no_weightadjust:
-	vdir_add_backend(ctx, rr->vd, vcl_be, w);
+	vdir_add_backend(ctx, rr->vd, args->backend, args->weight);
 	return;
 
   err:

src/vmod_weightadjust.vcc

@@ -24,7 +24,7 @@ Example::
 	new vdir = weightadjust.random();
 
 $Method VOID .add_backend(BACKEND backend, REAL weight,
-			  STRING weight_update=0,
+			  [REGEX weight_update],
 			  STRING url="/",
 			  STRING request=0,
 			  DURATION timeout=2,
@@ -47,7 +47,8 @@ Description
 	exactly one subexpression to capture a real value in C locale
 	format (ddd.ddd). The match is ran against the first *buffer*
 	bytes of the HTTP response, headers and body in multiline mode
-	(``^`` matches start of line, ``$`` matches end of line or end buffer).
+	(``^`` matches start of line, ``$`` matches end of line or end
+	buffer).
 
 	The interval to issue weight update requests is defined by the
 	*interval* parameter, the timeout both for sending and

src/wadj_thread.c

@@ -174,8 +174,8 @@ wadj_update(void *arg)
 	struct vdir *vd;
 	struct timespec due;
 	unsigned u = UINT_MAX;
-	const int ovsz = 2 * 3;
-	int i, ov[ovsz];
+	txt groups[2];
+	int i;
 	char *p, *pp;
 	AN(pr->bufsz);
 	char buf[pr->bufsz];
@@ -208,8 +208,8 @@ wadj_update(void *arg)
 
 		assert(len <= pr->bufsz);
 
-		i = VRE_exec(pr->vre, buf, len, 0, PCRE_NEWLINE_ANYCRLF,
-		    ov, ovsz, NULL);
+		// XXX should use VRE_MATCH_NOTBOL|VRE_MATCH_NOTEOL
+		i = VRE_capture(pr->vre, buf, len, 0 /*here*/, groups, 2, NULL);
 
 		if (i < 0) {
 			POKE_ERR(pr, "regular expression error %d", i);
@@ -221,10 +221,8 @@ wadj_update(void *arg)
 			    "need one caputuring match, got %d", i - 1);
 			continue;
 		}
-		assert(ov[2] < len);
-		assert(ov[3] < len);
-		p = buf + ov[2];
-		buf[ov[3]] = '\0';
+		groups[1].e = '\0';
+		p = (char *)groups[1].b;
 
 		errno = 0;
 		w = strtod(p, &pp);
@@ -361,7 +359,6 @@ wadj_prop_fini(struct wadj_prop **propp)
 	CHECK_OBJ_NOTNULL(prop, WADJ_PROP_MAGIC);
 	assert(prop->run == STOPPED);
 	AN(prop->vre);
-	VRE_free(&prop->vre);
 	AN(prop->req);
 	free(prop->req);
 	AZ(pthread_cond_destroy(&prop->wakeup.cv));

src/wadj_thread.h

@@ -53,7 +53,7 @@ struct wadj_prop {
 	pthread_t		thread;
 	struct wadj_prop_wakeup wakeup;
 	enum run_state_e	run;
-	vre_t			*vre;
+	VCL_REGEX		vre;
 	char			*req;
 	int			reqlen;
 	VCL_DURATION		timeout;