[totem-pl-parser/wip/hadess/async-save: 1/2] plparser: Add async versions of playlist saving

[Bastien Nocera <hadess src gnome org>]

commit 8005ecbd62eb6c72bf24fa00fa57c7cdc23f6f92
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Feb 27 17:27:11 2020 +0100

    plparser: Add async versions of playlist saving

 docs/reference/totem-pl-parser-sections.txt |   2 +
 plparse/plparser.map                        |   2 +
 plparse/totem-pl-parser.c                   | 206 ++++++++++++++++++++++++----
 plparse/totem-pl-parser.h                   |  11 ++
 4 files changed, 191 insertions(+), 30 deletions(-)
---
diff --git a/docs/reference/totem-pl-parser-sections.txt b/docs/reference/totem-pl-parser-sections.txt
index 23b77af..aff75bb 100644
--- a/docs/reference/totem-pl-parser-sections.txt
+++ b/docs/reference/totem-pl-parser-sections.txt
@@ -14,6 +14,8 @@ totem_pl_parser_parse_finish
 totem_pl_parser_parse_with_base
 totem_pl_parser_parse_with_base_async
 totem_pl_parser_save
+totem_pl_parser_save_async
+totem_pl_parser_save_finish
 totem_pl_parser_parse_duration
 totem_pl_parser_parse_date
 totem_pl_parser_add_ignored_scheme
diff --git a/plparse/plparser.map b/plparse/plparser.map
index 280308b..73d7568 100644
--- a/plparse/plparser.map
+++ b/plparse/plparser.map
@@ -31,6 +31,8 @@ LIBTOTEM_PL_PARSER_MINI_1.0 {
     totem_pl_parser_result_get_type;
     totem_pl_parser_type_get_type;
     totem_pl_parser_save;
+    totem_pl_parser_save_async;
+    totem_pl_parser_save_finish;
     totem_pl_parser_metadata_get_type;
     totem_pl_playlist_get_type;
     totem_pl_playlist_new;
diff --git a/plparse/totem-pl-parser.c b/plparse/totem-pl-parser.c
index 282e65a..0628f53 100644
--- a/plparse/totem-pl-parser.c
+++ b/plparse/totem-pl-parser.c
@@ -1108,6 +1108,92 @@ totem_pl_parser_resolve_uri (GFile *base_gfile,
 }
 
 #ifndef TOTEM_PL_PARSER_MINI
+typedef struct {
+       TotemPlPlaylist   *playlist;
+       GFile             *dest;
+       char              *title;
+       TotemPlParserType  type;
+} PlParserSaveData;
+
+static void
+pl_parser_save_data_free (PlParserSaveData *data)
+{
+       g_clear_object (&data->playlist);
+       g_clear_object (&data->dest);
+       g_clear_pointer (&data->title, g_free);
+       g_free (data);
+}
+
+static void
+pl_parser_save_thread (GTask        *task,
+                      gpointer      source_object,
+                      gpointer      task_data,
+                      GCancellable *cancellable)
+{
+       PlParserSaveData *data = task_data;
+       GError *error = NULL;
+       gboolean ret = FALSE;
+
+       switch (data->type) {
+       case TOTEM_PL_PARSER_PLS:
+               ret = totem_pl_parser_save_pls (source_object,
+                                               data->playlist,
+                                               data->dest,
+                                               data->title,
+                                               cancellable,
+                                               &error);
+               break;
+       case TOTEM_PL_PARSER_M3U:
+       case TOTEM_PL_PARSER_M3U_DOS:
+               ret = totem_pl_parser_save_m3u (source_object,
+                                               data->playlist,
+                                               data->dest,
+                                               (data->type == TOTEM_PL_PARSER_M3U_DOS),
+                                               cancellable,
+                                               &error);
+               break;
+       case TOTEM_PL_PARSER_XSPF:
+               ret = totem_pl_parser_save_xspf (source_object,
+                                                data->playlist,
+                                                data->dest,
+                                                data->title,
+                                                cancellable,
+                                                &error);
+               break;
+       case TOTEM_PL_PARSER_IRIVER_PLA:
+               ret = totem_pl_parser_save_pla (source_object,
+                                               data->playlist,
+                                               data->dest,
+                                               data->title,
+                                               cancellable,
+                                               &error);
+               break;
+       default:
+               g_assert_not_reached ();
+       }
+
+       if (ret == FALSE)
+               g_task_return_error (task, error);
+       else
+               g_task_return_boolean (task, TRUE);
+}
+
+static gboolean
+pl_parser_save_check_size (TotemPlPlaylist *playlist,
+                          GTask           *task)
+{
+       if (totem_pl_playlist_size (playlist) > 0)
+               return TRUE;
+
+       /* FIXME add translation */
+       g_task_return_new_error (task,
+                                TOTEM_PL_PARSER_ERROR,
+                                TOTEM_PL_PARSER_ERROR_EMPTY_PLAYLIST,
+                                "Playlist selected for saving is empty");
+       g_object_unref (task);
+       return FALSE;
+}
+
 /**
  * totem_pl_parser_save:
  * @parser: a #TotemPlParser
@@ -1145,38 +1231,98 @@ totem_pl_parser_save (TotemPlParser      *parser,
                       TotemPlParserType   type,
                       GError            **error)
 {
-        g_return_val_if_fail (TOTEM_PL_IS_PARSER (parser), FALSE);
-        g_return_val_if_fail (TOTEM_PL_IS_PLAYLIST (playlist), FALSE);
-        g_return_val_if_fail (G_IS_FILE (dest), FALSE);
-
-        if (totem_pl_playlist_size (playlist) == 0) {
-               /* FIXME add translation */
-               g_set_error (error,
-                            TOTEM_PL_PARSER_ERROR,
-                            TOTEM_PL_PARSER_ERROR_EMPTY_PLAYLIST,
-                            "Playlist selected for saving is empty");
-                return FALSE;
-        }
+       GTask *task;
+       PlParserSaveData *data;
 
-        switch (type)
-        {
-       case TOTEM_PL_PARSER_PLS:
-               return totem_pl_parser_save_pls (parser, playlist, dest, title, NULL, error);
-       case TOTEM_PL_PARSER_M3U:
-       case TOTEM_PL_PARSER_M3U_DOS:
-               return totem_pl_parser_save_m3u (parser, playlist, dest,
-                                                 (type == TOTEM_PL_PARSER_M3U_DOS),
-                                                 NULL,
-                                                 error);
-       case TOTEM_PL_PARSER_XSPF:
-               return totem_pl_parser_save_xspf (parser, playlist, dest, title, NULL, error);
-       case TOTEM_PL_PARSER_IRIVER_PLA:
-               return totem_pl_parser_save_pla (parser, playlist, dest, title, NULL, error);
-       default:
-               g_assert_not_reached ();
-       }
+       g_return_val_if_fail (TOTEM_PL_IS_PARSER (parser), FALSE);
+       g_return_val_if_fail (TOTEM_PL_IS_PLAYLIST (playlist), FALSE);
+       g_return_val_if_fail (G_IS_FILE (dest), FALSE);
 
-       return FALSE;
+       task = g_task_new (parser, NULL, NULL, NULL);
+       if (!pl_parser_save_check_size (playlist, task))
+               return g_task_propagate_boolean (task, error);
+
+       data = g_new0 (PlParserSaveData, 1);
+       data->playlist = g_object_ref (playlist);
+       data->dest = g_object_ref (dest);
+       data->title = g_strdup (title);
+       data->type = type;
+
+       g_task_set_task_data (task, data, (GDestroyNotify) pl_parser_save_data_free);
+       g_task_run_in_thread_sync (task, pl_parser_save_thread);
+
+       return g_task_propagate_boolean (task, error);
+}
+
+/**
+ * totem_pl_parser_save_async:
+ * @parser: a #TotemPlParser
+ * @playlist: a #TotemPlPlaylist
+ * @dest: output #GFile
+ * @title: the playlist title
+ * @type: a #TotemPlParserType for the outputted playlist
+ * @cancellable: (allow-none): a #GCancellable, or %NULL
+ * @callback: (allow-none): a #GAsyncReadyCallback to call when saving has finished
+ * @user_data: data to pass to the @callback function
+ *
+ * Starts asynchronous version of totem_pl_parser_save(). For more details
+ * see totem_pl_parser_save().
+ *
+ * When the operation is finished, @callback will be called. You can then call
+ * totem_pl_parser_save_finish() to get the results of the operation.
+ **/
+void
+totem_pl_parser_save_async (TotemPlParser        *parser,
+                           TotemPlPlaylist      *playlist,
+                           GFile                *dest,
+                           const gchar          *title,
+                           TotemPlParserType     type,
+                           GCancellable         *cancellable,
+                           GAsyncReadyCallback   callback,
+                           gpointer              user_data)
+{
+       GTask *task;
+       PlParserSaveData *data;
+
+       g_return_if_fail (TOTEM_PL_IS_PARSER (parser));
+       g_return_if_fail (TOTEM_PL_IS_PLAYLIST (playlist));
+       g_return_if_fail (G_IS_FILE (dest));
+
+       task = g_task_new (parser, cancellable, callback, user_data);
+       if (!pl_parser_save_check_size (playlist, task))
+               return;
+
+       data = g_new0 (PlParserSaveData, 1);
+       data->playlist = g_object_ref (playlist);
+       data->dest = g_object_ref (dest);
+       data->title = g_strdup (title);
+       data->type = type;
+
+       g_task_set_task_data (task, data, (GDestroyNotify) pl_parser_save_data_free);
+       g_task_run_in_thread (task, pl_parser_save_thread);
+}
+
+/**
+ * totem_pl_parser_save_finish:
+ * @parser: a #TotemPlParser
+ * @async_result: a #GAsyncResult
+ * @error: a #GError, or %NULL
+ *
+ * Finishes an asynchronous playlist saving operation started with totem_pl_parser_save_async().
+ *
+ * If saving of the playlist is cancelled part-way through, %G_IO_ERROR_CANCELLED will be
+ * returned when this function is called.
+ *
+ * Return value: %TRUE on success, %FALSE on failure.
+ **/
+gboolean
+totem_pl_parser_save_finish (TotemPlParser   *parser,
+                            GAsyncResult    *async_result,
+                            GError         **error)
+{
+       g_return_val_if_fail (g_task_is_valid (async_result, parser), NULL);
+
+       return g_task_propagate_boolean (G_TASK (async_result), error);
 }
 #endif /* TOTEM_PL_PARSER_MINI */
 
diff --git a/plparse/totem-pl-parser.h b/plparse/totem-pl-parser.h
index e37dcfe..fc1397b 100644
--- a/plparse/totem-pl-parser.h
+++ b/plparse/totem-pl-parser.h
@@ -349,6 +349,17 @@ gboolean totem_pl_parser_save (TotemPlParser      *parser,
                               const gchar        *title,
                               TotemPlParserType   type,
                               GError            **error);
+void totem_pl_parser_save_async (TotemPlParser        *parser,
+                                TotemPlPlaylist      *playlist,
+                                GFile                *dest,
+                                const gchar          *title,
+                                TotemPlParserType     type,
+                                GCancellable         *cancellable,
+                                GAsyncReadyCallback   callback,
+                                gpointer              user_data);
+gboolean totem_pl_parser_save_finish (TotemPlParser   *parser,
+                                     GAsyncResult    *result,
+                                     GError         **error);
 
 void      totem_pl_parser_add_ignored_scheme (TotemPlParser *parser,
                                               const char *scheme);