allow calling .policy multiple times on the cached result

README.rst

@@ -449,7 +449,7 @@ hosts.policy
 
 ::
 
-	INT hosts.policy(PRIV_TASK, STRING host, STRING path)
+	INT hosts.policy(PRIV_TASK, STRING host=0, STRING path=0)
 
 Determine the policy type that holds for ``host`` and ``path``. The
 return values are:
@@ -460,9 +460,8 @@ return values are:
 * -1 if no matching policy can be found
 * -2 if there was an internal error
 
-The ``host`` and ``path`` parameters are required, and must be
-non-empty. This method MAY NOT be called in ``vcl_init``. If it is,
-then the VCL load fails.
+This method MAY NOT be called in ``vcl_init``. If it is, then the VCL
+load fails.
 
 The method searches for host names added by the ``.add()`` method that
 match ``host``, possibly matching the suffix if the host name in
@@ -502,6 +501,13 @@ Subsequent calls to the ``.token()``, ``.secret()`` or ``.explain()``
 methods refer to the most recent invocation of ``.policy()`` in the
 same task scope, that is in the same client or backend transaction.
 
+Likewise, if both the ``host`` and ``path`` parameters are empty,
+``.policy()`` returns again the result of the most recent invocation
+with parameters.
+
+Calling ``.policy()`` with only one of the ``host`` and ``path``
+parameters empty is an error.
+
 .. _func_hosts.token:
 
 hosts.token

src/tests/policy_method.vtc

@@ -21,9 +21,13 @@ varnish v1 -vcl {
 	}
 
 	sub vcl_synth {
-		set resp.http.p1 = h.policy("example.com", "/foo/bar");
-		set resp.http.p2 = h.policy("example.org", "/quux/4711");
-		set resp.http.p3 = h.policy("example.com", "/bar/foo");
+		set resp.http.p0  = h.policy();
+		set resp.http.p1  = h.policy("example.com", "/foo/bar");
+		set resp.http.p1c = h.policy();
+		set resp.http.p2  = h.policy("example.org", "/quux/4711");
+		set resp.http.p2c = h.policy();
+		set resp.http.p3  = h.policy("example.com", "/bar/foo");
+		set resp.http.p3c = h.policy();
 	}
 } -start
 
@@ -31,9 +35,13 @@ client c1 {
 	txreq
 	rxresp
 	expect resp.status == 200
-	expect resp.http.p1 == "2"
-	expect resp.http.p2 == "1"
-	expect resp.http.p3 == "0"
+	expect resp.http.p0  == "-2"
+	expect resp.http.p1  == "2"
+	expect resp.http.p1c == "2"
+	expect resp.http.p2  == "1"
+	expect resp.http.p2c == "1"
+	expect resp.http.p3  == "0"
+	expect resp.http.p3c == "0"
 } -run
 
 # Examples from Akamai docs

src/vmod_hoailona.c

@@ -94,6 +94,11 @@ WS_Contains(struct ws * const restrict ws, const void * const restrict ptr,
         assert((char *)ptr >= ws->s && (char *)(ptr + len) <= ws->e);
 }
 
+static struct vmod_hoailona_policy *
+get_policy(VRT_CTX, const struct vmod_priv * restrict const,
+	   const char * restrict const,
+	   const char * restrict const);
+
 void
 errmsg(VRT_CTX, const char *fmt, ...)
 {
@@ -490,10 +495,24 @@ vmod_hosts_policy(VRT_CTX, struct vmod_hoailona_hosts *hosts,
 		return -2;
 	}
 	if (hostname == NULL || hostname[0] == '\0') {
-		VERR(ctx, "host is empty in %s.policy()", hosts->vcl_name);
-		return -2;
-	}
-	if (pathname == NULL || pathname[0] == '\0') {
+		if (! (pathname == NULL || pathname[0] == '\0')) {
+			VERR(ctx, "host is empty in %s.policy()",
+			     hosts->vcl_name);
+			return -2;
+		}
+
+		if (priv_task->priv == NULL) {
+			VERR(ctx, "%s.policy() no cached result",
+			     hosts->vcl_name);
+			return -2;
+		}
+
+		policy = get_policy(ctx, priv_task, hosts->vcl_name, "policy");
+
+		if (policy == NULL)
+			return -1;
+		return policy->type;
+	} else if (pathname == NULL || pathname[0] == '\0') {
 		VERR(ctx, "path is empty in %s.policy()", hosts->vcl_name);
 		return -2;
 	}

src/vmod_hoailona.vcc

@@ -399,7 +399,7 @@ Examples::
     h.add("evil.org", "deny", description="no access to evil.org");
   }
 
-$Method INT .policy(PRIV_TASK, STRING host, STRING path)
+$Method INT .policy(PRIV_TASK, STRING host=0, STRING path=0)
 
 Determine the policy type that holds for ``host`` and ``path``. The
 return values are:
@@ -410,9 +410,8 @@ return values are:
 * -1 if no matching policy can be found
 * -2 if there was an internal error
 
-The ``host`` and ``path`` parameters are required, and must be
-non-empty. This method MAY NOT be called in ``vcl_init``. If it is,
-then the VCL load fails.
+This method MAY NOT be called in ``vcl_init``. If it is, then the VCL
+load fails.
 
 The method searches for host names added by the ``.add()`` method that
 match ``host``, possibly matching the suffix if the host name in
@@ -452,6 +451,13 @@ Subsequent calls to the ``.token()``, ``.secret()`` or ``.explain()``
 methods refer to the most recent invocation of ``.policy()`` in the
 same task scope, that is in the same client or backend transaction.
 
+Likewise, if both the ``host`` and ``path`` parameters are empty,
+``.policy()`` returns again the result of the most recent invocation
+with parameters.
+
+Calling ``.policy()`` with only one of the ``host`` and ``path``
+parameters empty is an error.
+
 $Method STRING .token(PRIV_TASK, STRING acl=0, DURATION ttl=0, STRING data=0)
 
 If the previous invocation of ``.policy()`` determined policy type