Implement lv2:relation.

git-svn-id: http://svn.drobilla.net/lad/trunk/lilv@4002 a436a847-0d15-0410-975c-d299462d15a1

5 files changed, 43 insertions, 9 deletions

diff --git a/lilv/lilv.h b/lilv/lilv.h
index f41a4a9..fb9a7d9 100644
--- a/lilv/lilv.h
+++ b/lilv/lilv.h
@@ -899,15 +899,14 @@ lilv_plugin_get_port_by_symbol(const LilvPlugin* plugin,
                                const LilvNode*   symbol);
 
 /**
-   Get a port on @c plugin by an lv2:PortProperty.
-   This function only makes sense for port properties which apply to a single
-   port per plugin (like lv2:reportsLatency).  Otherwise, the matching port
-   with the lowest index will be returned.
+   Get a port on @c plugin by the lv2:relation it represents.
+   If the plugin has multiple ports with the same relation (which it should
+   not), the one with the lowest index will be returned.
 */
 LILV_API
 LilvPort*
-lilv_plugin_get_port_by_property(const LilvPlugin* plugin,
-                                 const LilvNode*   port_property);
+lilv_plugin_get_port_by_relation(const LilvPlugin* plugin,
+                                 const LilvNode*   relation);
 
 /**
    Get the full name of the plugin's author.
diff --git a/src/lilv_internal.h b/src/lilv_internal.h
index 18aaed5..a6d53f7 100644
--- a/src/lilv_internal.h
+++ b/src/lilv_internal.h
@@ -150,6 +150,7 @@ struct LilvWorldImpl {
 		SordNode* lv2_Plugin;
 		SordNode* lv2_port;
 		SordNode* lv2_portProperty;
+		SordNode* lv2_relation;
 		SordNode* lv2_reportsLatency;
 		SordNode* lv2_requiredFeature;
 		SordNode* lv2_Specification;
diff --git a/src/plugin.c b/src/plugin.c
index c6d36a7..df113a0 100644
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -585,8 +585,7 @@ lilv_plugin_has_latency(const LilvPlugin* p)
 	return ret;
 }
 
-LILV_API
-LilvPort*
+static LilvPort*
 lilv_plugin_get_port_by_property(const LilvPlugin* plugin,
                                  const LilvNode*   port_property)
 {
@@ -611,6 +610,31 @@ lilv_plugin_get_port_by_property(const LilvPlugin* plugin,
 }
 
 LILV_API
+LilvPort*
+lilv_plugin_get_port_by_relation(const LilvPlugin* plugin,
+                                 const LilvNode*   relation)
+{
+	lilv_plugin_load_ports_if_necessary(plugin);
+	for (uint32_t i = 0; i < plugin->num_ports; ++i) {
+		LilvPort* port = plugin->ports[i];
+		SordIter* iter = lilv_world_query_internal(
+			plugin->world,
+			port->node,
+			plugin->world->uris.lv2_relation,
+			relation->val.uri_val);
+
+		const bool found = !lilv_matches_end(iter);
+		lilv_match_end(iter);
+
+		if (found) {
+			return port;
+		}
+	}
+
+	return NULL;
+}
+
+LILV_API
 uint32_t
 lilv_plugin_get_latency_port_index(const LilvPlugin* p)
 {
diff --git a/src/world.c b/src/world.c
index 28a58c5..198a02a 100644
--- a/src/world.c
+++ b/src/world.c
@@ -62,6 +62,7 @@ lilv_world_new(void)
 	world->uris.lv2_Plugin          = NEW_URI(LILV_NS_LV2  "Plugin");
 	world->uris.lv2_port            = NEW_URI(LILV_NS_LV2  "port");
 	world->uris.lv2_portProperty    = NEW_URI(LILV_NS_LV2  "portProperty");
+	world->uris.lv2_relation        = NEW_URI(LILV_NS_LV2  "relation");
 	world->uris.lv2_reportsLatency  = NEW_URI(LILV_NS_LV2  "reportsLatency");
 	world->uris.lv2_requiredFeature = NEW_URI(LILV_NS_LV2  "requiredFeature");
 	world->uris.lv2_Specification   = NEW_URI(LILV_NS_LV2  "Specification");
diff --git a/test/lilv_test.c b/test/lilv_test.c
index b20b9df..b73d9e6 100644
--- a/test/lilv_test.c
+++ b/test/lilv_test.c
@@ -544,7 +544,8 @@ test_plugin(void)
 			"] , [ "
 			"  a lv2:ControlPort ; a lv2:OutputPort ; "
 			"  lv2:index 2 ; lv2:symbol \"latency\" ; lv2:name \"Latency\" ; "
-			"  lv2:portProperty lv2:reportsLatency "
+			"  lv2:portProperty lv2:reportsLatency ; "
+			"  lv2:relation lv2:latency "
 			"] . \n"
 			":thing doap:name \"Something else\" .\n"))
 		return 0;
@@ -612,6 +613,14 @@ test_plugin(void)
 	TEST_ASSERT(lilv_plugin_has_latency(plug));
 	TEST_ASSERT(lilv_plugin_get_latency_port_index(plug) == 2);
 
+	LilvNode* lv2_latency = lilv_new_uri(world,
+			"http://lv2plug.in/ns/lv2core#latency");
+	LilvPort* latency_port = lilv_plugin_get_port_by_relation(
+		plug, lv2_latency);
+
+	TEST_ASSERT(latency_port);
+	TEST_ASSERT(lilv_port_get_index(plug, latency_port) == 2);
+
 	LilvNode* rt_feature = lilv_new_uri(world,
 			"http://lv2plug.in/ns/lv2core#hardRTCapable");
 	LilvNode* event_feature = lilv_new_uri(world,