[gnome-software] shell search provider: Rewrite concurrent search handling logic

[Kalev Lember <klember src gnome org>]

commit 27588054ad6bb527166a7d2d2eecb3f12523c4ac
Author: Kalev Lember <kalevlember gmail com>
Date:   Sun Oct 5 20:07:09 2014 +0200

    shell search provider: Rewrite concurrent search handling logic
    
    I failed to wrap my head around the current logic. This commit rewrites
    the concurrency handling and simplifies it considerably, following
    similar patterns as in the rest of gnome-software.
    
    Not sure if this fixes the multitude of crashes reported against the
    search provider, but it should definitely make it easier for me to debug
    them in the future.

 src/gs-shell-search-provider.c |   77 +++++++++++----------------------------
 1 files changed, 22 insertions(+), 55 deletions(-)
---
diff --git a/src/gs-shell-search-provider.c b/src/gs-shell-search-provider.c
index 8f379bf..b2ae7aa 100644
--- a/src/gs-shell-search-provider.c
+++ b/src/gs-shell-search-provider.c
@@ -35,7 +35,6 @@
 typedef struct {
        GsShellSearchProvider *provider;
        GDBusMethodInvocation *invocation;
-       gint ref_count;
 } PendingSearch;
 
 struct _GsShellSearchProvider {
@@ -46,47 +45,17 @@ struct _GsShellSearchProvider {
        GsShellSearchProvider2 *skeleton;
        GsPluginLoader *plugin_loader;
        GCancellable *cancellable;
-       PendingSearch *current_search;
 
        GHashTable *metas_cache;
 };
 
 G_DEFINE_TYPE (GsShellSearchProvider, gs_shell_search_provider, G_TYPE_OBJECT)
 
-static PendingSearch *
-pending_search_ref (PendingSearch *search)
-{
-       search->ref_count++;
-
-       return search;
-}
-
 static void
-pending_search_unref (PendingSearch *search)
+pending_search_free (PendingSearch *search)
 {
-       search->ref_count--;
-
-       if (search->ref_count == 0)
-               g_slice_free (PendingSearch, search);
-}
-
-static void
-cancel_current_search (GsShellSearchProvider *self)
-{
-       if (self->current_search) {
-               PendingSearch *search;
-
-               g_cancellable_cancel (self->cancellable);
-               g_cancellable_reset (self->cancellable);
-
-               search = self->current_search;
-               self->current_search = NULL;
-
-               g_dbus_method_invocation_return_value (search->invocation, g_variant_new ("(as)", NULL));
-               search->invocation = NULL;
-
-               pending_search_unref (search);
-       }
+       g_object_unref (search->invocation);
+       g_slice_free (PendingSearch, search);
 }
 
 /**
@@ -115,17 +84,10 @@ search_done_cb (GObject *source,
        GList *list, *l;
        GVariantBuilder builder;
 
-       if (self->current_search != search) {
-               /* canceled */
-               pending_search_unref (search);
-               return;
-       }
-
-       pending_search_unref (search);
-
        list = gs_plugin_loader_search_finish (self->plugin_loader, res, NULL);
        if (list == NULL) {
-               cancel_current_search (self);
+               g_dbus_method_invocation_return_value (search->invocation, g_variant_new ("(as)", NULL));
+               pending_search_free (search);
                return; 
        }
 
@@ -139,12 +101,10 @@ search_done_cb (GObject *source,
                        continue;
                g_variant_builder_add (&builder, "s", gs_app_get_id (app));
        }
-       g_dbus_method_invocation_return_value (self->current_search->invocation, g_variant_new ("(as)", 
&builder));
+       g_dbus_method_invocation_return_value (search->invocation, g_variant_new ("(as)", &builder));
 
        g_list_free_full (list, g_object_unref);
-
-       pending_search_unref (self->current_search);
-       self->current_search = NULL;
+       pending_search_free (search);
 }
 
 static void
@@ -152,11 +112,15 @@ execute_search (GsShellSearchProvider  *self,
                GDBusMethodInvocation  *invocation,
                gchar                 **terms)
 {
+       PendingSearch *pending_search;
        gchar *string;
 
        string = g_strjoinv (" ", terms);
 
-       cancel_current_search (self);
+       if (self->cancellable != NULL) {
+               g_cancellable_cancel (self->cancellable);
+               g_clear_object (&self->cancellable);
+       }
 
        /* don't attempt searches for a single character */
        if (g_strv_length (terms) == 1 &&
@@ -165,15 +129,15 @@ execute_search (GsShellSearchProvider  *self,
                return;
        }
 
-       self->current_search = g_slice_new (PendingSearch);
-       self->current_search->provider = self;
-       self->current_search->invocation = invocation;
-       self->current_search->ref_count = 1;
+       pending_search = g_slice_new (PendingSearch);
+       pending_search->provider = self;
+       pending_search->invocation = g_object_ref (invocation);
 
+       self->cancellable = g_cancellable_new ();
        gs_plugin_loader_search_async (self->plugin_loader,
                                       string, 0, self->cancellable,
                                       search_done_cb,
-                                      pending_search_ref (self->current_search));
+                                      pending_search);
        g_free (string);
 }
 
@@ -364,11 +328,15 @@ search_provider_dispose (GObject *obj)
                g_clear_object (&self->skeleton);
        }
 
+       if (self->cancellable != NULL) {
+               g_cancellable_cancel (self->cancellable);
+               g_clear_object (&self->cancellable);
+       }
+
        g_clear_object (&self->object_manager);
        g_clear_object (&self->plugin_loader);
        g_clear_object (&self->cancellable);
        g_hash_table_destroy (self->metas_cache);
-       cancel_current_search (self);
        g_application_release (g_application_get_default ());
 
        G_OBJECT_CLASS (gs_shell_search_provider_parent_class)->dispose (obj);
@@ -409,5 +377,4 @@ gs_shell_search_provider_setup (GsShellSearchProvider *provider,
                                GsPluginLoader *loader)
 {
        provider->plugin_loader = g_object_ref (loader);
-       provider->cancellable = g_cancellable_new ();
 }