[tracker/wip/rishi/non-native: 7/8] libtracker-miner: Don't mix sync & async GFileEnumerator APIs

[Debarshi Ray <debarshir src gnome org>]

commit 082eb36e12452f2c6fb791cd46a2bb8eb49f616b
Author: Debarshi Ray <debarshir gnome org>
Date:   Tue Jan 9 13:50:50 2018 +0100

    libtracker-miner: Don't mix sync & async GFileEnumerator APIs
    
    This enables enumeration of non-native files because GVfs doesn't like
    to mix asynchronous & synchronous GFileEnumerators. If an enumerator
    is obtained through one API variant, then it should be used via the
    same API variant.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=792337

 src/libtracker-miner/tracker-file-data-provider.c |   93 +++++++++------------
 1 files changed, 39 insertions(+), 54 deletions(-)
---
diff --git a/src/libtracker-miner/tracker-file-data-provider.c 
b/src/libtracker-miner/tracker-file-data-provider.c
index 889f2b0..97ee9cc 100644
--- a/src/libtracker-miner/tracker-file-data-provider.c
+++ b/src/libtracker-miner/tracker-file-data-provider.c
@@ -29,12 +29,6 @@ struct _TrackerFileDataProvider {
        GObject parent_instance;
 };
 
-typedef struct {
-       GFile *url;
-       gchar *attributes;
-       TrackerDirectoryFlags flags;
-} BeginData;
-
 /**
  * SECTION:tracker-file-data-provider
  * @short_description: File based data provider for file:// descendant URIs
@@ -72,34 +66,6 @@ tracker_file_data_provider_init (TrackerFileDataProvider *fe)
 {
 }
 
-static BeginData *
-begin_data_new (GFile                 *url,
-                const gchar           *attributes,
-                TrackerDirectoryFlags  flags)
-{
-       BeginData *data;
-
-       data = g_slice_new0 (BeginData);
-       data->url = g_object_ref (url);
-       /* FIXME: inefficient */
-       data->attributes = g_strdup (attributes);
-       data->flags = flags;
-
-       return data;
-}
-
-static void
-begin_data_free (BeginData *data)
-{
-       if (!data) {
-               return;
-       }
-
-       g_object_unref (data->url);
-       g_free (data->attributes);
-       g_slice_free (BeginData, data);
-}
-
 static GFileEnumerator *
 file_data_provider_begin (TrackerDataProvider    *data_provider,
                           GFile                  *url,
@@ -152,32 +118,32 @@ file_data_provider_begin (TrackerDataProvider    *data_provider,
 }
 
 static void
-file_data_provider_begin_thread (GTask        *task,
-                                 gpointer      source_object,
-                                 gpointer      task_data,
-                                 GCancellable *cancellable)
+enumerate_children_cb (GObject       *source_object,
+                       GAsyncResult  *res,
+                       gpointer       user_data)
 {
-       TrackerDataProvider *data_provider = source_object;
+       GFile *url = G_FILE (source_object);
        GFileEnumerator *enumerator = NULL;
-       BeginData *data = task_data;
+       GTask *task = G_TASK (user_data);
        GError *error = NULL;
 
-       if (g_cancellable_set_error_if_cancelled (cancellable, &error)) {
-               enumerator = NULL;
-       } else {
-               enumerator = file_data_provider_begin (data_provider,
-                                                      data->url,
-                                                      data->attributes,
-                                                      data->flags,
-                                                      cancellable,
-                                                      &error);
-       }
-
+       enumerator = g_file_enumerate_children_finish (url, res, &error);
        if (error) {
+               if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+                       gchar *uri;
+
+                       uri = g_file_get_uri (url);
+                       g_warning ("Could not open directory '%s': %s",
+                                  uri, error->message);
+                       g_free (uri);
+               }
+
                g_task_return_error (task, error);
        } else {
                g_task_return_pointer (task, enumerator, (GDestroyNotify) g_object_unref);
        }
+
+       g_object_unref (task);
 }
 
 static void
@@ -190,12 +156,31 @@ file_data_provider_begin_async (TrackerDataProvider   *data_provider,
                                 GAsyncReadyCallback    callback,
                                 gpointer               user_data)
 {
+       GFileQueryInfoFlags file_flags;
        GTask *task;
 
        task = g_task_new (data_provider, cancellable, callback, user_data);
-       g_task_set_task_data (task, begin_data_new (url, attributes, flags), (GDestroyNotify) 
begin_data_free);
-       g_task_set_priority (task, io_priority);
-       g_task_run_in_thread (task, file_data_provider_begin_thread);
+
+       /* We ignore the TRACKER_DIRECTORY_FLAG_NO_STAT here, it makes
+        * no sense to be at this point with that flag. So we warn
+        * about it...
+        */
+       if ((flags & TRACKER_DIRECTORY_FLAG_NO_STAT) != 0) {
+               g_warning ("Did not expect to have TRACKER_DIRECTORY_FLAG_NO_STAT "
+                          "flag in %s(), continuing anyway...",
+                          __FUNCTION__);
+       }
+
+       file_flags = G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS;
+
+       g_file_enumerate_children_async (url,
+                                        attributes,
+                                        file_flags,
+                                        io_priority,
+                                        cancellable,
+                                        enumerate_children_cb,
+                                        g_object_ref (task));
+
        g_object_unref (task);
 }