[tracker/wip/carlosg/tracker-3.0-api-breaks: 75/100] libtracker-sparql: Prepare for doing asynchronous queries

[Carlos Garnacho <carlosg src gnome org>]

commit f871c2ade34e29c11e55452458cf0f3085d36471
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Jan 26 23:37:00 2020 +0100

    libtracker-sparql: Prepare for doing asynchronous queries
    
    Operate on the cached elements as they are stored in the sequence
    and the cache struct, we will see it being passed along asynchronous
    queries soon.

 src/libtracker-direct/tracker-direct.c   |  1 -
 src/libtracker-sparql/tracker-notifier.c | 63 ++++++++++++++++----------------
 2 files changed, 31 insertions(+), 33 deletions(-)
---
diff --git a/src/libtracker-direct/tracker-direct.c b/src/libtracker-direct/tracker-direct.c
index 9270f74e8..1009701dc 100644
--- a/src/libtracker-direct/tracker-direct.c
+++ b/src/libtracker-direct/tracker-direct.c
@@ -457,7 +457,6 @@ commit_statement_cb (gpointer user_data)
        while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &cache)) {
                g_hash_table_iter_steal (&iter);
                _tracker_notifier_event_cache_flush_events (cache);
-               _tracker_notifier_event_cache_free (cache);
        }
 }
 
diff --git a/src/libtracker-sparql/tracker-notifier.c b/src/libtracker-sparql/tracker-notifier.c
index 6ee186109..a1381a817 100644
--- a/src/libtracker-sparql/tracker-notifier.c
+++ b/src/libtracker-sparql/tracker-notifier.c
@@ -284,39 +284,37 @@ tracker_notifier_event_cache_take_events (TrackerNotifierEventCache *cache)
        return events;
 }
 
-static TrackerNotifierEvent *
-find_event_in_array (GPtrArray *events,
-                     gint64     id,
-                     gint      *idx)
+static void
+tracker_notifier_emit_events (TrackerNotifierEventCache *cache)
 {
-       TrackerNotifierEvent *event;
+       GPtrArray *events;
 
-       while (*idx < events->len) {
-               event = g_ptr_array_index (events, *idx);
-               (*idx)++;
-               if (event->id == id)
-                       return event;
-       }
+       events = tracker_notifier_event_cache_take_events (cache);
 
-       return NULL;
+       if (events) {
+               g_signal_emit (cache->notifier, signals[EVENTS], 0, cache->service, cache->graph, events);
+               g_ptr_array_unref (events);
+       }
 }
 
 static gchar *
-create_extra_info_query (TrackerNotifier *notifier,
-                         GPtrArray       *events)
+create_extra_info_query (TrackerNotifier           *notifier,
+                         TrackerNotifierEventCache *cache)
 {
        TrackerNotifierPrivate *priv;
        GString *sparql, *filter;
        gboolean has_elements = FALSE;
-       gint idx;
+       GSequenceIter *iter;
 
        priv = tracker_notifier_get_instance_private (notifier);
        filter = g_string_new (NULL);
 
-       for (idx = 0; idx < events->len; idx++) {
+       for (iter = g_sequence_get_begin_iter (cache->sequence);
+            !g_sequence_iter_is_end (iter);
+            iter = g_sequence_iter_next (iter)) {
                TrackerNotifierEvent *event;
 
-               event = g_ptr_array_index (events, idx);
+               event = g_sequence_get (iter);
 
                if (has_elements)
                        g_string_append_c (filter, ' ');
@@ -344,17 +342,18 @@ create_extra_info_query (TrackerNotifier *notifier,
 }
 
 static void
-tracker_notifier_query_extra_info (TrackerNotifier *notifier,
-                                   GPtrArray       *events)
+tracker_notifier_query_extra_info (TrackerNotifier           *notifier,
+                                   TrackerNotifierEventCache *cache)
 {
        TrackerNotifierPrivate *priv;
        TrackerSparqlCursor *cursor;
        TrackerNotifierEvent *event;
+       GSequenceIter *iter;
        gchar *sparql;
-       gint idx = 0, col;
+       gint col;
        gint64 id;
 
-       sparql = create_extra_info_query (notifier, events);
+       sparql = create_extra_info_query (notifier, cache);
        if (!sparql)
                return;
 
@@ -363,6 +362,8 @@ tracker_notifier_query_extra_info (TrackerNotifier *notifier,
                                                  NULL, NULL);
        g_free (sparql);
 
+       iter = g_sequence_get_begin_iter (cache->sequence);
+
        /* We rely here in both the GPtrArray and the query items being
         * sorted by tracker:id, the former will be so because the way it's
         * extracted from the GSequence, the latter because of the ORDER BY
@@ -371,9 +372,10 @@ tracker_notifier_query_extra_info (TrackerNotifier *notifier,
        while (tracker_sparql_cursor_next (cursor, NULL, NULL)) {
                col = 0;
                id = tracker_sparql_cursor_get_integer (cursor, col++);
-               event = find_event_in_array (events, id, &idx);
+               event = g_sequence_get (iter);
+               iter = g_sequence_iter_next (iter);
 
-               if (!event) {
+               if (!event || event->id != id) {
                        g_critical ("Queried for id %" G_GINT64_FORMAT " but it is not "
                                    "found, bailing out", id);
                        break;
@@ -391,17 +393,15 @@ _tracker_notifier_event_cache_flush_events (TrackerNotifierEventCache *cache)
 {
        TrackerNotifier *notifier = cache->notifier;
        TrackerNotifierPrivate *priv = tracker_notifier_get_instance_private (notifier);
-       GPtrArray *events;
 
-       events = tracker_notifier_event_cache_take_events (cache);
+       if (g_sequence_is_empty (cache->sequence))
+               _tracker_notifier_event_cache_free (cache);
 
-       if (events) {
-               if (priv->flags & TRACKER_NOTIFIER_FLAG_QUERY_URN)
-                       tracker_notifier_query_extra_info (notifier, events);
+       if (priv->flags & TRACKER_NOTIFIER_FLAG_QUERY_URN)
+               tracker_notifier_query_extra_info (notifier, cache);
 
-               g_signal_emit (notifier, signals[EVENTS], 0, cache->service, cache->graph, events);
-               g_ptr_array_unref (events);
-       }
+       tracker_notifier_emit_events (cache);
+       _tracker_notifier_event_cache_free (cache);
 }
 
 static void
@@ -429,7 +429,6 @@ graph_updated_cb (GDBusConnection *connection,
        g_variant_iter_free (events);
 
        _tracker_notifier_event_cache_flush_events (cache);
-       _tracker_notifier_event_cache_free (cache);
 }
 
 static void