[tracker/wip/carlosg/notifier-service-queries: 10/12] libtracker-sparql: Perform notifier queries on the right service

[Carlos Garnacho <carlosg src gnome org>]

commit 9d46bf7aae2c51463cf9e67751029ffed7fa0b53
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Jun 21 14:45:19 2020 +0200

    libtracker-sparql: Perform notifier queries on the right service
    
    We must figure out (and shortcut) the cases where the service matches
    our own connection one (In the case of a bus TrackerSparqlConnection).
    In any other case, perform the queries on the same service that issued
    the GraphUpdated signal.
    
    Also ensure we set a coherent "service" argument in the ::events signal
    for those same connections.
    
    Fixes: https://gitlab.gnome.org/GNOME/tracker/-/issues/227

 src/libtracker-direct/tracker-direct.c           |  2 +-
 src/libtracker-sparql/tracker-notifier-private.h |  1 -
 src/libtracker-sparql/tracker-notifier.c         | 89 +++++++++++++++++++-----
 3 files changed, 74 insertions(+), 18 deletions(-)
---
diff --git a/src/libtracker-direct/tracker-direct.c b/src/libtracker-direct/tracker-direct.c
index ebae03d95..355c5debf 100644
--- a/src/libtracker-direct/tracker-direct.c
+++ b/src/libtracker-direct/tracker-direct.c
@@ -405,7 +405,7 @@ lookup_event_cache (TrackerNotifier *notifier,
        cache = g_hash_table_lookup (events, GINT_TO_POINTER (graph_id));
 
        if (!cache) {
-               cache = _tracker_notifier_event_cache_new (notifier, NULL, graph);
+               cache = _tracker_notifier_event_cache_new (notifier, graph);
                g_hash_table_insert (events, GINT_TO_POINTER (graph_id), cache);
        }
 
diff --git a/src/libtracker-sparql/tracker-notifier-private.h 
b/src/libtracker-sparql/tracker-notifier-private.h
index 9d019f6ca..aabe9f1bc 100644
--- a/src/libtracker-sparql/tracker-notifier-private.h
+++ b/src/libtracker-sparql/tracker-notifier-private.h
@@ -27,7 +27,6 @@
 typedef struct _TrackerNotifierEventCache TrackerNotifierEventCache;
 
 TrackerNotifierEventCache * _tracker_notifier_event_cache_new (TrackerNotifier *notifier,
-                                                               const gchar     *service,
                                                                const gchar     *graph);
 void _tracker_notifier_event_cache_free (TrackerNotifierEventCache *event_cache);
 
diff --git a/src/libtracker-sparql/tracker-notifier.c b/src/libtracker-sparql/tracker-notifier.c
index 7601e1aea..1f529f584 100644
--- a/src/libtracker-sparql/tracker-notifier.c
+++ b/src/libtracker-sparql/tracker-notifier.c
@@ -71,6 +71,7 @@
 #include "tracker-private.h"
 #include "tracker-sparql-enum-types.h"
 #include <libtracker-common/tracker-common.h>
+#include <libtracker-bus/tracker-bus.h>
 
 typedef struct _TrackerNotifierPrivate TrackerNotifierPrivate;
 typedef struct _TrackerNotifierSubscription TrackerNotifierSubscription;
@@ -91,7 +92,7 @@ struct _TrackerNotifierPrivate {
 };
 
 struct _TrackerNotifierEventCache {
-       gchar *service;
+       TrackerNotifierSubscription *subscription;
        gchar *graph;
        TrackerNotifier *notifier;
        GSequence *sequence;
@@ -192,29 +193,35 @@ compare_event_cb (gconstpointer a,
        return event1->id - event2->id;
 }
 
-TrackerNotifierEventCache *
-_tracker_notifier_event_cache_new (TrackerNotifier *notifier,
-                                   const gchar     *service,
-                                   const gchar     *graph)
+static TrackerNotifierEventCache *
+_tracker_notifier_event_cache_new_full (TrackerNotifier             *notifier,
+                                        TrackerNotifierSubscription *subscription,
+                                        const gchar                 *graph)
 {
        TrackerNotifierEventCache *event_cache;
 
        event_cache = g_new0 (TrackerNotifierEventCache, 1);
        event_cache->notifier = g_object_ref (notifier);
-       event_cache->service = g_strdup (service);
+       event_cache->subscription = subscription;
        event_cache->graph = g_strdup (graph);
        event_cache->sequence = g_sequence_new ((GDestroyNotify) tracker_notifier_event_unref);
 
        return event_cache;
 }
 
+TrackerNotifierEventCache *
+_tracker_notifier_event_cache_new (TrackerNotifier *notifier,
+                                   const gchar     *graph)
+{
+       return _tracker_notifier_event_cache_new_full (notifier, NULL, graph);
+}
+
 void
 _tracker_notifier_event_cache_free (TrackerNotifierEventCache *event_cache)
 {
        g_sequence_free (event_cache->sequence);
        g_object_unref (event_cache->notifier);
        g_free (event_cache->graph);
-       g_free (event_cache->service);
        g_free (event_cache);
 }
 
@@ -309,16 +316,53 @@ compose_uri (const gchar *service,
                return g_strdup_printf ("dbus:%s", service);
 }
 
+static gchar *
+get_service_name (TrackerNotifier           *notifier,
+                  TrackerNotifierEventCache *cache)
+{
+       TrackerNotifierSubscription *subscription;
+       TrackerNotifierPrivate *priv;
+
+       priv = tracker_notifier_get_instance_private (notifier);
+       subscription = cache->subscription;
+
+       if (!subscription)
+               return NULL;
+
+       if (TRACKER_BUS_IS_CONNECTION (priv->connection)) {
+               gchar *bus_name, *bus_object_path;
+               gboolean is_self;
+
+               g_object_get (priv->connection,
+                             "bus-name", &bus_name,
+                             "bus-object-path", &bus_object_path,
+                             NULL);
+
+               is_self = (g_strcmp0 (bus_name, subscription->service) == 0 &&
+                          g_strcmp0 (bus_object_path, subscription->object_path) == 0);
+               g_free (bus_name);
+               g_free (bus_object_path);
+
+               if (is_self)
+                       return NULL;
+       }
+
+       return compose_uri (subscription->service, subscription->object_path);
+}
+
 static gboolean
 tracker_notifier_emit_events (TrackerNotifierEventCache *cache)
 {
        GPtrArray *events;
+       gchar *service;
 
        events = tracker_notifier_event_cache_take_events (cache);
 
        if (events) {
-               g_signal_emit (cache->notifier, signals[EVENTS], 0, cache->service, cache->graph, events);
+               service = get_service_name (cache->notifier, cache);
+               g_signal_emit (cache->notifier, signals[EVENTS], 0, service, cache->graph, events);
                g_ptr_array_unref (events);
+               g_free (service);
        }
 
        return G_SOURCE_REMOVE;
@@ -339,6 +383,7 @@ create_extra_info_query (TrackerNotifier           *notifier,
 {
        GString *sparql, *filter;
        gboolean has_elements = FALSE;
+       gchar *service;
        GSequenceIter *iter;
 
        filter = g_string_new (NULL);
@@ -362,13 +407,29 @@ create_extra_info_query (TrackerNotifier           *notifier,
                return NULL;
        }
 
-       sparql = g_string_new ("SELECT ?id tracker:uri(xsd:integer(?id)) ");
+       sparql = g_string_new ("SELECT ?id ?uri ");
+
+       service = get_service_name (notifier, cache);
+
+       if (service) {
+               g_string_append_printf (sparql,
+                                       "{ SERVICE <%s> ",
+                                       service);
+       }
 
        g_string_append_printf (sparql,
-                               "{ VALUES ?id { %s } } "
-                               "ORDER BY ?id", filter->str);
+                               "{ VALUES ?id { %s }"
+                               "  BIND (tracker:uri(?id) AS ?uri)"
+                               "}", filter->str);
        g_string_free (filter, TRUE);
 
+       if (service)
+               g_string_append (sparql, "} ");
+
+       g_string_append (sparql, "ORDER BY ?id");
+
+       g_free (service);
+
        return g_string_free (sparql, FALSE);
 }
 
@@ -474,14 +535,10 @@ graph_updated_cb (GDBusConnection *connection,
        TrackerNotifierEventCache *cache;
        GVariantIter *events;
        const gchar *graph;
-       gchar *service;
 
        g_variant_get (parameters, "(sa{ii})", &graph, &events);
 
-       service = compose_uri (subscription->service, subscription->object_path);
-       cache = _tracker_notifier_event_cache_new (notifier, service, graph);
-       g_free (service);
-
+       cache = _tracker_notifier_event_cache_new_full (notifier, subscription, graph);
        handle_events (notifier, cache, events);
        g_variant_iter_free (events);