Saner (internal) query API, though still needs work.

Preliminary (untested) support for host features/extensions/whatever.
Documentation fixes and minor cleanups.


git-svn-id: http://svn.drobilla.net/lad/libslv2@113 a436a847-0d15-0410-975c-d299462d15a1

5 files changed, 233 insertions, 87 deletions

diff --git a/slv2/plugin.h b/slv2/plugin.h
index 57fa266..95d933e 100644
--- a/slv2/plugin.h
+++ b/slv2/plugin.h
@@ -179,6 +179,50 @@ slv2_plugin_has_latency(const SLV2Plugin* p);
 uint32_t
 slv2_plugin_get_latency_port(const SLV2Plugin* p);
 
+#if 0
+/** Return whether or not a plugin supports the given host feature / extension.
+ *
+ * This will return true for both supported and required host features.
+ */
+bool
+slv2_plugin_supports_feature(const SLV2Plugin* p, const char* feature_uri);
+
+
+/** Return whether or not a plugin requires the given host feature / extension.
+ *
+ * If a plugin requires a feature, that feature MUST be passed to the plugin's
+ * instantiate method or the plugin will fail to instantiate.
+ */
+bool
+slv2_plugin_requires_features(const SLV2Plugin* p, const char* feature_uri);
+#endif
+
+/** Get a plugin's supported host features / extensions.
+ *
+ * This returns a list of all supported features (both required and optional).
+ */
+SLV2Property
+slv2_plugin_get_supported_features(const SLV2Plugin* p);
+
+
+/** Get a plugin's requires host features / extensions.
+ *
+ * All feature URI's returned by this call MUST be passed to the plugin's
+ * instantiate method for the plugin to instantiate successfully.
+ */
+SLV2Property
+slv2_plugin_get_required_features(const SLV2Plugin* p);
+
+
+/** Get a plugin's optional host features / extensions.
+ *
+ * If the feature URI's returned by this method are passed to the plugin's
+ * instantiate method, those features will be used by the function, otherwise
+ * the plugin will act as it would if it did not support that feature at all.
+ */
+SLV2Property
+slv2_plugin_get_optional_features(const SLV2Plugin* p);
+
 
 /** @} */
 
diff --git a/slv2/query.h b/slv2/query.h
index 9f1c93d..a23df0e 100644
--- a/slv2/query.h
+++ b/slv2/query.h
@@ -74,23 +74,32 @@ char*
 slv2_query_lang_filter(const char* variable);
 
 
-/** Run a SPARQL query on a plugin's data file.
+/** Run a SPARQL query on a plugin's data file and return variable matches.
  *
  * Header from slv2query_header will be prepended to passed query string (so
  * the default prefixes will be already defined, you don't need to add them
  * yourself).
  *
- * rasqal_init() must be called by the caller before calling this function.
+ * Returned is a list of all matches for the query variable \a var_name.
  */
-rasqal_query_results*
-slv2_plugin_run_query(const SLV2Plugin* p,
-                      const char*       query_string);
+SLV2Property
+slv2_query_get_results(const SLV2Plugin* p,
+                       const char*       query_string,
+                       const char*       var_name);
+
 
+/** Run a SPARQL query on a plugin's data file and just count the matches.
+ *
+ * Header from slv2query_header will be prepended to passed query string (so
+ * the default prefixes will be already defined, you don't need to add them
+ * yourself).
+ *
+ * Returned is the total of all variable matches resulting from the query.
+ */
 size_t
-slv2_query_get_num_results(rasqal_query_results* results, const char* var_name);
+slv2_query_count_results(const SLV2Plugin* p,
+                         const char*       query_string);
 
-SLV2Property
-slv2_query_get_results(rasqal_query_results* results, const char* var_name);
 
 /** Free an SLV2Property. */
 void
diff --git a/src/plugin.c b/src/plugin.c
index a024077..65903da 100644
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -130,7 +130,6 @@ SLV2Property
 slv2_plugin_get_property(const SLV2Plugin* p,
                          const char*      property)
 {
-	assert(p);
 	assert(property);
 
 	/*
@@ -147,19 +146,13 @@ slv2_plugin_get_property(const SLV2Plugin* p,
 	free(header);
 	free(lang_filter);*/
 
-	rasqal_init();
-	
     char* query = strjoin(
 		"SELECT DISTINCT ?value FROM data: WHERE { \n"
 		"plugin: ", property, " ?value . \n"
 		"} \n", NULL);
 
-	rasqal_query_results* results = slv2_plugin_run_query(p, query);
+	SLV2Property result = slv2_query_get_results(p, query, "value");
 	
-	SLV2Property result = slv2_query_get_results(results, "value");
-
-	rasqal_free_query_results(results);
-	rasqal_finish();
 	free(query);
 
 	return result;
@@ -169,54 +162,45 @@ slv2_plugin_get_property(const SLV2Plugin* p,
 uint32_t
 slv2_plugin_get_num_ports(const SLV2Plugin* p)
 {
-	rasqal_init();
-	
     char* query = strjoin(
 		"SELECT DISTINCT ?value FROM data: WHERE { \n"
 		"plugin: lv2:port ?value . \n"
 		"} \n", NULL);
 
-	rasqal_query_results* results = slv2_plugin_run_query(p, query);
-	const size_t result = slv2_query_get_num_results(results, "value");
+	SLV2Property results = slv2_query_get_results(p, query, "value");
+	
+	size_t count = results->num_values;
 	
-	rasqal_free_query_results(results);
-	rasqal_finish();
 	free(query);
+	slv2_property_free(results);
 
-	return result;
+	return count;
 }
 
 
 bool
 slv2_plugin_has_latency(const SLV2Plugin* p)
 {
-	assert(p);
-
-	rasqal_init();
-	
     char* query = 
 		"SELECT DISTINCT ?value FROM data: WHERE { \n"
 		"	plugin: lv2:port     ?port . \n"
 		"	?port   lv2:portHint lv2:reportsLatency . \n"
 		"}\n";
 
-	rasqal_query_results* results = slv2_plugin_run_query(p, query);
-	bool result = ( rasqal_query_results_get_bindings_count(results) > 0 );
+	SLV2Property results = slv2_query_get_results(p, query, "port");
+	
+	bool exists = (results->num_values > 0);
 	
-	rasqal_free_query_results(results);
-	rasqal_finish();
-    free(query);
+	free(query);
+	slv2_property_free(results);
 
-	return result;
+	return exists;
 }
 
+
 uint32_t
 slv2_plugin_get_latency_port(const SLV2Plugin* p)
 {
-	assert(p);
-
-	rasqal_init();
-	
     char* query = 
 		"SELECT DISTINCT ?value FROM data: WHERE { \n"
 		"	plugin: lv2:port     ?port . \n"
@@ -224,9 +208,7 @@ slv2_plugin_get_latency_port(const SLV2Plugin* p)
 		"           lv2:index    ?index . \n"
 		"}\n";
 
-	rasqal_query_results* results = slv2_plugin_run_query(p, query);
-	
-	struct _Property* result = slv2_query_get_results(results, "index");
+	SLV2Property result = slv2_query_get_results(p, query, "index");
 	
 	// FIXME: need a sane error handling strategy
 	assert(result->num_values == 1);
@@ -234,10 +216,70 @@ slv2_plugin_get_latency_port(const SLV2Plugin* p)
 	uint32_t index = strtol(result->values[0], &endptr, 10);
 	// FIXME: check.. stuff..
 	
-	rasqal_free_query_results(results);
-	rasqal_finish();
 	free(query);
 
 	return index;
 }
 
+/*
+bool
+slv2_plugin_supports_feature(const SLV2Plugin* p, const char* feature_uri)
+{
+}
+
+
+bool
+slv2_plugin_requires_feature(const SLV2Plugin* p, const char* feature_uri)
+{
+}
+*/
+
+SLV2Property
+slv2_plugin_get_supported_features(const SLV2Plugin* p)
+{
+    char* query = 
+		"SELECT DISTINCT ?feature FROM data: WHERE { \n"
+		"	{ plugin:  lv2:requiredHostFeature  ?feature } \n"
+		"		UNION \n"
+		"	{ plugin:  lv2:supportedHostFeature  ?feature } \n"
+		"}\n";
+
+	SLV2Property result = slv2_query_get_results(p, query, "feature");
+	
+	free(query);
+
+	return result;
+}
+
+
+SLV2Property
+slv2_plugin_get_optional_features(const SLV2Plugin* p)
+{
+    char* query = 
+		"SELECT DISTINCT ?feature FROM data: WHERE { \n"
+		"	plugin:  lv2:supportedHostFeature  ?feature . \n"
+		"}\n";
+
+	SLV2Property result = slv2_query_get_results(p, query, "feature");
+	
+	free(query);
+
+	return result;
+}
+
+
+SLV2Property
+slv2_plugin_get_required_features(const SLV2Plugin* p)
+{
+    char* query = 
+		"SELECT DISTINCT ?feature FROM data: WHERE { \n"
+		"	plugin:  lv2:requiredHostFeature  ?feature . \n"
+		"}\n";
+
+	SLV2Property result = slv2_query_get_results(p, query, "feature");
+	
+	free(query);
+
+	return result;
+}
+
diff --git a/src/port.c b/src/port.c
index 111517d..1ca149d 100644
--- a/src/port.c
+++ b/src/port.c
@@ -73,13 +73,10 @@ slv2_port_get_property(SLV2Plugin* p,
                        uint32_t    index,
                        const char* property)
 {
-	assert(p);
 	assert(property);
 
-	char index_str[4];
-	snprintf(index_str, (size_t)4, "%u", index);
-	
-	rasqal_init();
+	char index_str[16];
+	snprintf(index_str, (size_t)16, "%u", index);
 	
     char* query = strjoin(
 		"SELECT DISTINCT ?value FROM data: WHERE { \n"
@@ -87,12 +84,8 @@ slv2_port_get_property(SLV2Plugin* p,
 		"?port lv2:index ", index_str, " . \n"
 		"?port ", property, " ?value . \n}\n", NULL);
 
-	rasqal_query_results* results = slv2_plugin_run_query(p, query);
+	SLV2Property result = slv2_query_get_results(p, query, "value");
 	
-	SLV2Property result = slv2_query_get_results(results, "value");
-
-	rasqal_free_query_results(results);
-	rasqal_finish();
 	free(query);
 
 	return result;
@@ -103,7 +96,6 @@ char*
 slv2_port_get_symbol(SLV2Plugin* p,
                      uint32_t    index)
 {
-	// FIXME: leaks
 	char* result = NULL;
 	
 	SLV2Property prop
diff --git a/src/query.c b/src/query.c
index 56903ac..177d06e 100644
--- a/src/query.c
+++ b/src/query.c
@@ -58,9 +58,55 @@ slv2_query_lang_filter(const char* variable)
 }
 
 
-rasqal_query_results*
-slv2_plugin_run_query(const SLV2Plugin* p,
-                      const char*       query)
+SLV2Property
+slv2_query_get_variable_bindings(rasqal_query_results* results, const char* var_name)
+{
+	struct _Property* result = NULL;
+
+    if (rasqal_query_results_get_bindings_count(results) > 0) {
+        result = malloc(sizeof(struct _Property));
+        result->num_values = 0;
+        result->values = NULL;
+    }
+
+    while (!rasqal_query_results_finished(results)) {
+
+        rasqal_literal* literal =
+            rasqal_query_results_get_binding_value_by_name(results, (const unsigned char*)var_name);
+        assert(literal != NULL);
+
+        // Add value on to the array, reallocing all the way.
+		// Yes, this is disgusting.  Roughly as disgusting as the rasqal query
+		// results API.  coincidentally.
+        result->num_values++;
+        result->values = realloc(result->values, result->num_values * sizeof(char*));
+        result->values[result->num_values-1] = strdup((const char*)rasqal_literal_as_string(literal));
+
+        rasqal_query_results_next(results);
+    }
+
+    return result;
+}
+
+
+size_t
+slv2_query_count_variable_bindings(rasqal_query_results* results)
+{
+	size_t count = 0;
+
+    while (!rasqal_query_results_finished(results)) {
+		++count;
+        rasqal_query_results_next(results);
+    }
+
+    return count;
+}
+
+
+SLV2Property
+slv2_query_get_results(const SLV2Plugin* p,
+                       const char*       query,
+                       const char*       var_name)
 {
 	char* header    = slv2_query_header(p);
 	char* query_str = strjoin(header, query, NULL);
@@ -68,21 +114,63 @@ slv2_plugin_run_query(const SLV2Plugin* p,
 	assert(p);
 	assert(query_str);
 
+	rasqal_init();
+
 	rasqal_query *rq = rasqal_new_query("sparql", NULL);
 
 	//printf("Query: \n%s\n\n", query_str);
 
 	rasqal_query_prepare(rq, (unsigned char*)query_str, NULL);
 	rasqal_query_results* results = rasqal_query_execute(rq);
+	assert(results);
 	
+	SLV2Property ret = slv2_query_get_variable_bindings(results, var_name);
+	rasqal_free_query_results(results);
 	rasqal_free_query(rq);
 	
+	rasqal_finish();
+	
 	free(query_str);
 	free(header);
+
+	return ret;
+}
+
+
+size_t
+slv2_query_count_results(const SLV2Plugin* p,
+                         const char*       query)
+{
+	char* header    = slv2_query_header(p);
+	char* query_str = strjoin(header, query, NULL);
+
+	assert(p);
+	assert(query_str);
+
+	rasqal_init();
+
+	rasqal_query *rq = rasqal_new_query("sparql", NULL);
+
+	//printf("Query: \n%s\n\n", query_str);
+
+	rasqal_query_prepare(rq, (unsigned char*)query_str, NULL);
+	rasqal_query_results* results = rasqal_query_execute(rq);
+	assert(results);
 	
-	return results;
+	size_t count = slv2_query_count_variable_bindings(results);
+	
+	rasqal_free_query_results(results);
+	rasqal_free_query(rq);
+	
+	rasqal_finish();
+	
+	free(query_str);
+	free(header);
+
+	return count;
 }
 
+/*
 size_t
 slv2_query_get_num_results(rasqal_query_results* results, const char* var_name)
 {
@@ -97,36 +185,7 @@ slv2_query_get_num_results(rasqal_query_results* results, const char* var_name)
 
 	return result;
 }
-
-SLV2Property
-slv2_query_get_results(rasqal_query_results* results, const char* var_name)
-{
-	struct _Property* result = NULL;
-
-    if (rasqal_query_results_get_bindings_count(results) > 0) {
-        result = malloc(sizeof(struct _Property));
-        result->num_values = 0;
-        result->values = NULL;
-    }
-
-    while (!rasqal_query_results_finished(results)) {
-
-        rasqal_literal* literal =
-            rasqal_query_results_get_binding_value_by_name(results, (const unsigned char*)var_name);
-        assert(literal != NULL);
-
-        // Add value on to the array, reallocing all the way.
-		// Yes, this is disgusting.  Roughly as disgusting as the rasqal query
-		// results API.  coincidentally.
-        result->num_values++;
-        result->values = realloc(result->values, result->num_values * sizeof(char*));
-        result->values[result->num_values-1] = strdup((const char*)rasqal_literal_as_string(literal));
-
-        rasqal_query_results_next(results);
-    }
-
-    return result;
-}
+*/
 
 void
 slv2_property_free(struct _Property* prop)