Tweak the file transfer portal _again_

This is a neverending story. I was seeing problems in tests where
the nested mainloop was picking up unrelated timeouts.

Break down and make this async. This changes the ordering in which
the (de)serializers are registered. If this is causing issues, we
can introduce priorities or something else.

1 files changed, 239 insertions, 149 deletions

diff --git a/gdk/filetransferportal.c b/gdk/filetransferportal.c
index ba5f6d4ef0..541fd85a24 100644
--- a/gdk/filetransferportal.c
+++ b/gdk/filetransferportal.c
@@ -23,6 +23,10 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include "gdkcontentformats.h"
+#include "gdkcontentserializer.h"
+#include "gdkcontentdeserializer.h"
+
 #include <gio/gio.h>
 
 #ifdef G_OS_UNIX
@@ -42,145 +46,6 @@
 #include "filetransferportalprivate.h"
 
 static GDBusProxy *file_transfer_proxy = NULL;
-static gboolean done;
-static guint timeout_id;
-
-static void
-got_proxy (GObject *source,
-           GAsyncResult *result,
-           gpointer data)
-{
-  GError *error = NULL;
-
-  file_transfer_proxy = g_dbus_proxy_new_for_bus_finish (result, &error);
-  if (!file_transfer_proxy)
-    {
-      g_message ("failed to get file transfer portal proxy: %s", error->message);
-      g_error_free (error);
-    }
-
-  if (timeout_id)
-    {
-      g_source_remove (timeout_id);
-      timeout_id = 0;
-    }
-
-  done = TRUE;
-  g_main_context_wakeup (NULL);
-}
-
-static void
-got_bus (GObject *source,
-         GAsyncResult *result,
-         gpointer data)
-{
-  GDBusConnection **bus = data;
-  GError *error = NULL;
-
-  *bus = g_bus_get_finish (result, &error);
-  if (!*bus)
-    {
-      g_message ("failed to get session bus connection: %s", error->message);
-      g_error_free (error);
-    }
-
-  if (timeout_id)
-    {
-      g_source_remove (timeout_id);
-      timeout_id = 0;
-    }
-
-  done = TRUE;
-  g_main_context_wakeup (NULL);
-}
-
-static gboolean
-give_up_on_proxy (gpointer data)
-{
-  GCancellable *cancellable = data;
-
-  g_cancellable_cancel (cancellable);
-
-  timeout_id = 0;
-
-  done = TRUE;
-  g_main_context_wakeup (NULL);
-
-  return G_SOURCE_REMOVE;
-}
-
-static GDBusProxy *
-ensure_file_transfer_portal (void)
-{
-  if (file_transfer_proxy == NULL)
-    {
-      GCancellable *cancellable;
-      GDBusConnection *bus = NULL;
-
-      cancellable = g_cancellable_new ();
- 
-      done = FALSE;
-      timeout_id = g_timeout_add (500, give_up_on_proxy, cancellable);
-      g_bus_get (G_BUS_TYPE_SESSION,
-                 cancellable,
-                 got_bus,
-                 &bus);
-
-      while (!done)
-        g_main_context_iteration (NULL, TRUE);
-
-      if (bus)
-        {
-          done = FALSE;
-          timeout_id = g_timeout_add (500, give_up_on_proxy, cancellable);
-          g_dbus_proxy_new (bus,
-                            G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES
-                            | G_DBUS_PROXY_FLAGS_DO_NOT_CONNECT_SIGNALS
-                            | G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
-                            NULL,
-                            "org.freedesktop.portal.Documents",
-                            "/org/freedesktop/portal/documents",
-                            "org.freedesktop.portal.FileTransfer",
-                            cancellable,
-                            got_proxy,
-                            NULL);
-
-          while (!done)
-            g_main_context_iteration (NULL, TRUE);
-
-          g_clear_object (&bus);
-        }
-
-      g_clear_object (&cancellable);
-    }
-
-  if (file_transfer_proxy)
-    {
-      char *owner = g_dbus_proxy_get_name_owner (file_transfer_proxy);
-
-      if (owner)
-        {
-          g_free (owner);
-          return file_transfer_proxy;
-        }
-    }
-
-  return NULL;
-}
-
-gboolean
-file_transfer_portal_available (void)
-{
-  gboolean available;
-
-  ensure_file_transfer_portal ();
-
-  available = file_transfer_proxy != NULL;
-
-  g_clear_object (&file_transfer_proxy);
-
-  return available;
-}
 
 typedef struct {
   GTask *task;
@@ -328,15 +193,12 @@ file_transfer_portal_register_files (const char          **files,
                                      gpointer              data)
 {
   GTask *task;
-  GDBusProxy *proxy;
   AddFileData *afd;
   GVariantBuilder options;
 
   task = g_task_new (NULL, NULL, callback, data);
 
-  proxy = ensure_file_transfer_portal ();
-
-  if (proxy == NULL)
+  if (file_transfer_proxy == NULL)
     {
       g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
                                "No portal found");
@@ -354,7 +216,7 @@ file_transfer_portal_register_files (const char          **files,
   g_variant_builder_add (&options, "{sv}", "writable", g_variant_new_boolean (writable));
   g_variant_builder_add (&options, "{sv}", "autostop", g_variant_new_boolean (TRUE));
 
-  g_dbus_proxy_call (proxy, "StartTransfer",
+  g_dbus_proxy_call (file_transfer_proxy, "StartTransfer",
                      g_variant_new ("(a{sv})", &options),
                      0, -1, NULL, start_session_done, afd);
 }
@@ -406,15 +268,12 @@ file_transfer_portal_retrieve_files (const char          *key,
                                      GAsyncReadyCallback  callback,
                                      gpointer             data)
 {
-  GDBusProxy *proxy;
   GTask *task;
   GVariantBuilder options;
 
   task = g_task_new (NULL, NULL, callback, data);
 
-  proxy = ensure_file_transfer_portal ();
-
-  if (proxy == NULL)
+  if (file_transfer_proxy == NULL)
     {
       g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
                                "No portal found");
@@ -423,7 +282,7 @@ file_transfer_portal_retrieve_files (const char          *key,
     }
 
   g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
-  g_dbus_proxy_call (proxy,
+  g_dbus_proxy_call (file_transfer_proxy,
                      "RetrieveFiles",
                      g_variant_new ("(sa{sv})", key, &options),
                      0, -1, NULL,
@@ -444,4 +303,235 @@ file_transfer_portal_retrieve_files_finish (GAsyncResult   *result,
   return FALSE;
 }
 
+
+/* serializer */
+
+static void
+file_serializer_finish (GObject      *source,
+                        GAsyncResult *result,
+                        gpointer      serializer)
+{
+  GOutputStream *stream = G_OUTPUT_STREAM (source);
+  GError *error = NULL;
+
+  if (!g_output_stream_write_all_finish (stream, result, NULL, &error))
+    gdk_content_serializer_return_error (serializer, error);
+  else
+    gdk_content_serializer_return_success (serializer);
+}
+
+static void
+portal_ready (GObject *object,
+              GAsyncResult *result,
+              gpointer serializer)
+{
+  GError *error = NULL;
+  char *key;
+
+  if (!file_transfer_portal_register_files_finish (result, &key, &error))
+    {
+      gdk_content_serializer_return_error (serializer, error);
+      return;
+    }
+
+  g_output_stream_write_all_async (gdk_content_serializer_get_output_stream (serializer),
+                                   key,
+                                   strlen (key) + 1,
+                                   gdk_content_serializer_get_priority (serializer),
+                                   gdk_content_serializer_get_cancellable (serializer),
+                                   file_serializer_finish,
+                                   serializer);
+  gdk_content_serializer_set_task_data (serializer, key, g_free);
+}
+
+static void
+portal_file_serializer (GdkContentSerializer *serializer)
+{
+  GFile *file;
+  const GValue *value;
+  GPtrArray *files;
+
+  files = g_ptr_array_new_with_free_func (g_free);
+
+  value = gdk_content_serializer_get_value (serializer);
+
+  if (G_VALUE_HOLDS (value, G_TYPE_FILE))
+    {
+      file = g_value_get_object (gdk_content_serializer_get_value (serializer));
+      if (file)
+        g_ptr_array_add (files, g_file_get_path (file));
+      g_ptr_array_add (files, NULL);
+    }
+  else if (G_VALUE_HOLDS (value, GDK_TYPE_FILE_LIST))
+    {
+      GSList *l;
+
+      for (l = g_value_get_boxed (value); l; l = l->next)
+        g_ptr_array_add (files, g_file_get_path (l->data));
+
+      g_ptr_array_add (files, NULL);
+    }
+
+  /* this call doesn't copy the strings, so keep the array around until the registration is done */
+  file_transfer_portal_register_files ((const char **)files->pdata, TRUE, portal_ready, serializer);
+  gdk_content_serializer_set_task_data (serializer, files, (GDestroyNotify)g_ptr_array_unref);
+}
+
+/* deserializer */
+
+static void
+portal_finish (GObject *object,
+               GAsyncResult *result,
+               gpointer deserializer)
+{
+  char **files = NULL;
+  GError *error = NULL;
+  GValue *value;
+
+  if (!file_transfer_portal_retrieve_files_finish (result, &files, &error))
+    {
+      gdk_content_deserializer_return_error (deserializer, error);
+      return;
+    }
+
+  value = gdk_content_deserializer_get_value (deserializer);
+  if (G_VALUE_HOLDS (value, G_TYPE_FILE))
+    {
+      if (files[0] != NULL)
+        g_value_take_object (value, g_file_new_for_path (files[0]));
+    }
+  else
+    {
+      GSList *l = NULL;
+      gsize i;
+
+      for (i = 0; files[i] != NULL; i++)
+        l = g_slist_prepend (l, g_file_new_for_path (files[i]));
+      g_value_take_boxed (value, g_slist_reverse (l));
+    }
+  g_strfreev (files);
+
+  gdk_content_deserializer_return_success (deserializer);
+}
+
+static void
+portal_file_deserializer_finish (GObject      *source,
+                                 GAsyncResult *result,
+                                 gpointer      deserializer)
+{
+  GOutputStream *stream = G_OUTPUT_STREAM (source);
+  GError *error = NULL;
+  gssize written;
+  char *key;
+
+  written = g_output_stream_splice_finish (stream, result, &error);
+  if (written < 0)
+    {
+      gdk_content_deserializer_return_error (deserializer, error);
+      return;
+    }
+
+  /* write terminating NULL */
+  if (!g_output_stream_write (stream, "", 1, NULL, &error))
+    {
+      gdk_content_deserializer_return_error (deserializer, error);
+      return;
+    }
+
+  key = g_memory_output_stream_steal_data (G_MEMORY_OUTPUT_STREAM (stream));
+  if (key == NULL)
+    {
+      GError *gerror = g_error_new (G_IO_ERROR,
+                                    G_IO_ERROR_NOT_FOUND,
+                                    "Could not convert data from %s to %s",
+                                    gdk_content_deserializer_get_mime_type (deserializer),
+                                    g_type_name (gdk_content_deserializer_get_gtype (deserializer)));
+      gdk_content_deserializer_return_error (deserializer, gerror);
+      return;
+    }
+
+  file_transfer_portal_retrieve_files (key, portal_finish, deserializer);
+  gdk_content_deserializer_set_task_data (deserializer, key, g_free);
+}
+
+static void
+portal_file_deserializer (GdkContentDeserializer *deserializer)
+{
+  GOutputStream *output;
+
+  output = g_memory_output_stream_new_resizable ();
+
+  g_output_stream_splice_async (output,
+                                gdk_content_deserializer_get_input_stream (deserializer),
+                                G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE | G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET,
+                                gdk_content_deserializer_get_priority (deserializer),
+                                gdk_content_deserializer_get_cancellable (deserializer),
+                                portal_file_deserializer_finish,
+                                deserializer);
+  g_object_unref (output);
+}
+
+static void
+got_proxy (GObject *source,
+           GAsyncResult *result,
+           gpointer data)
+{
+  GError *error = NULL;
+
+  file_transfer_proxy = g_dbus_proxy_new_for_bus_finish (result, &error);
+  if (!file_transfer_proxy)
+    {
+      g_message ("Failed to get file transfer portal: %s", error->message);
+      g_clear_error (&error);
+      return;
+    }
+
+  gdk_content_register_serializer (G_TYPE_FILE,
+                                   "application/vnd.portal.files",
+                                   portal_file_serializer,
+                                   NULL,
+                                   NULL);
+
+  gdk_content_register_serializer (GDK_TYPE_FILE_LIST,
+                                   "application/vnd.portal.files",
+                                   portal_file_serializer,
+                                   NULL,
+                                   NULL);
+
+  gdk_content_register_deserializer ("application/vnd.portal.files",
+                                     GDK_TYPE_FILE_LIST,
+                                     portal_file_deserializer,
+                                     NULL,
+                                     NULL);
+
+  gdk_content_register_deserializer ("application/vnd.portal.files",
+                                     G_TYPE_FILE,
+                                     portal_file_deserializer,
+                                     NULL,
+                                     NULL);
+}
+
+void
+file_transfer_portal_register (void)
+{
+  static gboolean called;
+
+  if (!called)
+    {
+      called = TRUE;
+      g_dbus_proxy_new_for_bus (G_BUS_TYPE_SESSION,
+                                G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES
+                                | G_DBUS_PROXY_FLAGS_DO_NOT_CONNECT_SIGNALS
+                                | G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+                                NULL,
+                                "org.freedesktop.portal.Documents",
+                                "/org/freedesktop/portal/documents",
+                                "org.freedesktop.portal.FileTransfer",
+                                NULL,
+                                got_proxy,
+                                NULL);
+    }
+}
+
+
 #endif /* G_OS_UNIX */