Add lilv_nodes_merge() to API (address part of #835).

More lightweight version of lilv_plugin_has_feature() and lilv_world_find_nodes().


git-svn-id: http://svn.drobilla.net/lad/trunk/lilv@4860 a436a847-0d15-0410-975c-d299462d15a1

3 files changed, 46 insertions, 41 deletions

diff --git a/src/collections.c b/src/collections.c
index f7a035a..a4ac744 100644
--- a/src/collections.c
+++ b/src/collections.c
@@ -143,6 +143,25 @@ lilv_nodes_contains(const LilvNodes* list, const LilvNode* value)
 	return false;
 }
 
+LILV_API
+LilvNodes*
+lilv_nodes_merge(const LilvNodes* a, const LilvNodes* b)
+{
+	LilvNodes* result = lilv_nodes_new();
+
+	LILV_FOREACH(nodes, i, a)
+		zix_tree_insert((ZixTree*)result,
+		                lilv_node_duplicate(lilv_nodes_get(a, i)),
+		                NULL);
+
+	LILV_FOREACH(nodes, i, b)
+		zix_tree_insert((ZixTree*)result,
+		                lilv_node_duplicate(lilv_nodes_get(b, i)),
+		                NULL);
+
+	return result;
+}
+
 /* Iterator */
 
 #define LILV_COLLECTION_IMPL(prefix, CT, ET) \
diff --git a/src/plugin.c b/src/plugin.c
index 9912112..c284d98 100644
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -680,13 +680,17 @@ bool
 lilv_plugin_has_feature(const LilvPlugin* p,
                         const LilvNode*   feature)
 {
-	LilvNodes* features = lilv_plugin_get_supported_features(p);
+	const SordNode* predicates[] = { p->world->uris.lv2_requiredFeature,
+	                                 p->world->uris.lv2_optionalFeature,
+	                                 NULL };
 
-	const bool ret = (features && feature
-	                  && lilv_nodes_contains(features, feature));
-
-	lilv_nodes_free(features);
-	return ret;
+	for (const SordNode** pred = predicates; *pred; ++pred) {
+		if (lilv_world_ask_internal(
+			    p->world, p->plugin_uri->node, *pred, feature->node)) {
+			return true;
+		}
+	}
+	return false;
 }
 
 LILV_API
@@ -695,20 +699,9 @@ lilv_plugin_get_supported_features(const LilvPlugin* p)
 {
 	LilvNodes* optional = lilv_plugin_get_optional_features(p);
 	LilvNodes* required = lilv_plugin_get_required_features(p);
-	LilvNodes* result   = lilv_nodes_new();
-
-	LILV_FOREACH(nodes, i, optional)
-		zix_tree_insert((ZixTree*)result,
-		                lilv_node_duplicate(lilv_nodes_get(optional, i)),
-		                NULL);
-	LILV_FOREACH(nodes, i, required)
-		zix_tree_insert((ZixTree*)result,
-		                lilv_node_duplicate(lilv_nodes_get(required, i)),
-		                NULL);
-
+	LilvNodes* result   = lilv_nodes_merge(optional, required);
 	lilv_nodes_free(optional);
 	lilv_nodes_free(required);
-
 	return result;
 }
 
@@ -716,16 +709,20 @@ LILV_API
 LilvNodes*
 lilv_plugin_get_optional_features(const LilvPlugin* p)
 {
-	return lilv_plugin_get_value_internal(
-		p, p->world->uris.lv2_optionalFeature);
+	return lilv_world_query_values_internal(p->world,
+	                                        p->plugin_uri->node,
+	                                        p->world->uris.lv2_optionalFeature,
+	                                        NULL);
 }
 
 LILV_API
 LilvNodes*
 lilv_plugin_get_required_features(const LilvPlugin* p)
 {
-	return lilv_plugin_get_value_internal(
-		p, p->world->uris.lv2_requiredFeature);
+	return lilv_world_query_values_internal(p->world,
+	                                        p->plugin_uri->node,
+	                                        p->world->uris.lv2_requiredFeature,
+	                                        NULL);
 }
 
 LILV_API
diff --git a/src/world.c b/src/world.c
index afa3422..121f59c 100644
--- a/src/world.c
+++ b/src/world.c
@@ -185,31 +185,20 @@ lilv_world_find_nodes(LilvWorld*      world,
 		LILV_ERRORF("Subject `%s' is not a resource\n",
 		            sord_node_get_string(subject->node));
 		return NULL;
-	}
-	if (!lilv_node_is_uri(predicate)) {
+	} else if (!lilv_node_is_uri(predicate)) {
 		LILV_ERRORF("Predicate `%s' is not a URI\n",
 		            sord_node_get_string(predicate->node));
 		return NULL;
-	}
-	if (!subject && !object) {
+	} else if (!subject && !object) {
 		LILV_ERROR("Both subject and object are NULL\n");
 		return NULL;
 	}
-
-	SordNode* const subject_node = subject
-		? sord_node_copy(subject->node)
-		: NULL;
-
-	SordNode* const object_node = object
-		? sord_node_copy(object->node)
-		: NULL;
-
-	LilvNodes* ret = lilv_world_query_values_internal(
-		world, subject_node, predicate->node, object_node);
-
-	sord_node_free(world->world, subject_node);
-	sord_node_free(world->world, object_node);
-	return ret;
+	
+	return lilv_world_query_values_internal(
+		world,
+		subject ? subject->node : NULL,
+		predicate->node,
+		object ? object->node : NULL);
 }
 
 SordIter*