Changeset 2081

Timestamp:

06/03/09 12:38:56 (9 months ago)

Author:

drobilla

Message:

Avoid sorting/searching during plugin discovery if results happen to be in order (without actually requesting this with ORDER BY, which can be slower).
This should perform relatively well with any RDF backend, which tend to return sorted results anyway as an implementation detail (and redland with trees does).

Files:

• trunk/slv2/src/world.c (modified) (4 diffs)

trunk/slv2/src/world.c

@@ -518 +518 @@
 
         // Find all plugins and associated data files
-        unsigned char* query_string = (unsigned char*)
+        const unsigned char* query_string = (unsigned char*)
                 "PREFIX : <http://lv2plug.in/ns/lv2core#>\n"
                 "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>\n"
@@ -524 +524 @@
                 "SELECT DISTINCT ?plugin ?data ?bundle\n"
                 "WHERE { ?plugin a :Plugin; slv2:bundleURI ?bundle; rdfs:seeAlso ?data }\n";
-                //"ORDER BY ?plugin\n";
 
         librdf_query* q = librdf_new_query(world->world, "sparql",
@@ -532 +531 @@
 
         while (!librdf_query_results_finished(results)) {
-
                 librdf_node* plugin_node = librdf_query_results_get_binding_value(results, 0);
                 librdf_uri*  plugin_uri  = librdf_node_get_uri(plugin_node);
@@ -540 +538 @@
                 librdf_uri*  bundle_uri  = librdf_node_get_uri(bundle_node);
 
-                assert(plugin_uri);
-                assert(data_uri);
-
-                SLV2Value   uri    = slv2_value_new_librdf_uri(world, plugin_uri);
-                SLV2Plugin  plugin = slv2_plugins_get_by_uri(world->plugins, uri);
-
-                // Create a new SLV2Plugin
-                if (!plugin) {
-                        plugin = slv2_plugin_new(world, uri, bundle_uri);
-                        raptor_sequence_push(world->plugins, plugin);
-                        // FIXME: Slow!  ORDER BY broken in certain versions of redland?
-                        raptor_sequence_sort(world->plugins, slv2_plugin_compare_by_uri);
-                } else {
-                        slv2_value_free(uri);
+                if (plugin_uri && data_uri) {
+                        SLV2Plugin plugin = NULL;
+
+                        // Check if this is another match for the last plugin (avoid search)
+                        const unsigned n_plugins = raptor_sequence_size(world->plugins);
+                        if (n_plugins >= 1) {
+                                SLV2Plugin prev = raptor_sequence_get_at(world->plugins, n_plugins - 1);
+                                if (librdf_uri_equals(plugin_uri, prev->plugin_uri->val.uri_val))
+                                        plugin = prev;
+                        }
+
+                        SLV2Value uri = slv2_value_new_librdf_uri(world, plugin_uri);
+
+                        // If this plugin differs from the last, append a new SLV2Plugin
+                        if (!plugin) {
+                                if (n_plugins == 0) {
+                                        plugin = slv2_plugin_new(world, uri, bundle_uri);
+                                        raptor_sequence_push(world->plugins, plugin);
+                                } else {
+                                        SLV2Plugin first = raptor_sequence_get_at(world->plugins, 0);
+                                        SLV2Plugin prev  = raptor_sequence_get_at(world->plugins, n_plugins - 1);
+
+                                        // If the URI is > the last in the list, just append (avoid sort)
+                                        if (strcmp(
+                                                        slv2_value_as_string(slv2_plugin_get_uri(prev)),
+                                                        librdf_uri_as_string(plugin_uri)) < 0) {
+                                                plugin = slv2_plugin_new(world, uri, bundle_uri);
+                                                raptor_sequence_push(world->plugins, plugin);
+
+                                        // If the URI is < the first in the list, just prepend (avoid sort)
+                                        } else if (strcmp(
+                                                        slv2_value_as_string(slv2_plugin_get_uri(first)),
+                                                        librdf_uri_as_string(plugin_uri)) > 0) {
+                                                plugin = slv2_plugin_new(world, uri, bundle_uri);
+                                                raptor_sequence_shift(world->plugins, plugin);
+
+                                        // Otherwise the query engine is giving us unsorted results :/
+                                        } else {
+                                                plugin = slv2_plugins_get_by_uri(world->plugins, uri);
+                                                if (!plugin) {
+                                                        plugin = slv2_plugin_new(world, uri, bundle_uri);
+                                                        raptor_sequence_push(world->plugins, plugin);
+                                                        raptor_sequence_sort(world->plugins, slv2_plugin_compare_by_uri);
+                                                }
+                                        }
+                                }
+                        }
+
+                        plugin->world = world;
+
+                        // FIXME: check for duplicates
+                        raptor_sequence_push(plugin->data_uris,
+                                        slv2_value_new_librdf_uri(plugin->world, data_uri));
                 }
-
-                plugin->world = world;
-
-                // FIXME: check for duplicates
-                raptor_sequence_push(plugin->data_uris,
-                                slv2_value_new_librdf_uri(plugin->world, data_uri));
 
                 librdf_free_node(plugin_node);