sdgui: load dictionaries in parallel, as sdtui did

Also, resolve some use-after-frees in GTK+.

src/sdgui.c

@@ -26,16 +26,6 @@
 #include "utils.h"
 #include "stardict-view.h"
 
-typedef struct dictionary Dictionary;
-
-struct dictionary
-{
-	const gchar  *filename;          ///< Filename
-	StardictDict *dict;              ///< Stardict dictionary data
-	gchar        *name;              ///< Name to show
-	guint         position;          ///< Current position
-};
-
 static struct
 {
 	GtkWidget    *window;            ///< Top-level window
@@ -44,8 +34,7 @@ static struct
 	GtkWidget    *view;              ///< Entries view
 
 	gint          dictionary;        ///< Index of the current dictionary
-	Dictionary   *dictionaries;      ///< All open dictionaries
-	gsize         dictionaries_len;  ///< Total number of dictionaries
+	GPtrArray    *dictionaries;      ///< All open dictionaries
 
 	gboolean      watch_selection;   ///< Following X11 PRIMARY?
 }
@@ -53,37 +42,62 @@ g;
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-static gboolean
-dictionary_load (Dictionary *self, gchar *filename, GError **e)
+static void
+init (gchar **filenames)
 {
-	self->filename = filename;
-	if (!(self->dict = stardict_dict_new (self->filename, e)))
+	for (gsize i = 0; filenames[i]; i++)
+	{
+		Dictionary *dict = g_malloc0 (sizeof *dict);
+		dict->filename = g_strdup (filenames[i]);
+		g_ptr_array_add (g.dictionaries, dict);
+	}
+}
+
+// TODO: try to deduplicate, similar to app_load_config_values()
+static gboolean
+init_from_key_file (GKeyFile *kf, GError **error)
+{
+	const gchar *dictionaries = "Dictionaries";
+	gchar **names = g_key_file_get_keys (kf, dictionaries, NULL, NULL);
+	if (!names)
+		return TRUE;
+
+	for (gsize i = 0; names[i]; i++)
+	{
+		Dictionary *dict = g_malloc0 (sizeof *dict);
+		dict->name = names[i];
+		g_ptr_array_add (g.dictionaries, dict);
+	}
+	g_free (names);
+
+	for (gsize i = 0; i < g.dictionaries->len; i++)
+	{
+		Dictionary *dict = g_ptr_array_index (g.dictionaries, i);
+		gchar *path =
+			g_key_file_get_string (kf, dictionaries, dict->name, error);
+		if (!path)
 			return FALSE;
 
-	if (!self->name)
-	{
-		self->name = g_strdup (stardict_info_get_book_name
-			(stardict_dict_get_info (self->dict)));
+		// Try to resolve relative paths and expand tildes
+		if (!(dict->filename =
+			resolve_filename (path, resolve_relative_config_filename)))
+			dict->filename = path;
+		else
+			g_free (path);
 	}
 	return TRUE;
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
 static gboolean
-init (gchar **filenames, GError **e)
+init_from_config (GError **error)
 {
-	while (filenames[g.dictionaries_len])
-		g.dictionaries_len++;
-
-	g.dictionaries = g_malloc0_n (sizeof *g.dictionaries, g.dictionaries_len);
-	for (gsize i = 0; i < g.dictionaries_len; i++)
-	{
-		Dictionary *dict = &g.dictionaries[i];
-		if (!dictionary_load (dict, filenames[i], e))
+	GKeyFile *key_file = load_project_config_file (error);
+	if (!key_file)
 		return FALSE;
-	}
-	return TRUE;
+
+	gboolean result = init_from_key_file (key_file, error);
+	g_key_file_free (key_file);
+	return result;
 }
 
 static void
@@ -94,18 +108,17 @@ search (Dictionary *dict)
 
 	StardictIterator *iterator =
 		stardict_dict_search (dict->dict, input_utf8, NULL);
-	dict->position = stardict_iterator_get_offset (iterator);
+	stardict_view_set_position (STARDICT_VIEW (g.view),
+		dict->dict, stardict_iterator_get_offset (iterator));
 	g_object_unref (iterator);
 
-	stardict_view_set_position (STARDICT_VIEW (g.view),
-		dict->dict, dict->position);
 	stardict_view_set_matched (STARDICT_VIEW (g.view), input_utf8);
 }
 
 static void
 on_changed (G_GNUC_UNUSED GtkWidget *widget, G_GNUC_UNUSED gpointer data)
 {
-	search (&g.dictionaries[g.dictionary]);
+	search (g_ptr_array_index (g.dictionaries, g.dictionary));
 }
 
 static void
@@ -141,7 +154,7 @@ on_switch_page (G_GNUC_UNUSED GtkWidget *widget, G_GNUC_UNUSED GtkWidget *page,
 	guint page_num, G_GNUC_UNUSED gpointer data)
 {
 	g.dictionary = page_num;
-	search (&g.dictionaries[g.dictionary]);
+	search (g_ptr_array_index (g.dictionaries, g.dictionary));
 }
 
 static gboolean
@@ -205,7 +218,7 @@ main (int argc, char *argv[])
 	GOptionEntry option_entries[] =
 	{
 		{G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames,
-			NULL, N_("FILE...")},
+			NULL, N_("[FILE]...")},
 		{},
 	};
 
@@ -219,12 +232,18 @@ main (int argc, char *argv[])
 		return 1;
 	}
 
-	if (!filenames)
-	{
-		// TODO: eventually just load all dictionaries from configuration
-		die_with_dialog ("No arguments have been passed.");
-	}
-	if (!init (filenames, &error))
+	g.dictionaries =
+		g_ptr_array_new_with_free_func ((GDestroyNotify) dictionary_destroy);
+	if (filenames)
+		init (filenames);
+	else if (!init_from_config (&error) && error)
+		die_with_dialog (error->message);
+	g_strfreev (filenames);
+
+	if (!g.dictionaries->len)
+		die_with_dialog (_("No dictionaries found either in "
+			"the configuration or on the command line"));
+	if (!load_dictionaries (g.dictionaries, &error))
 		die_with_dialog (error->message);
 
 	// Some Adwaita stupidity
@@ -290,9 +309,9 @@ main (int argc, char *argv[])
 	g.view = stardict_view_new ();
 	gtk_box_pack_end (GTK_BOX (superbox), g.view, TRUE, TRUE, 0);
 
-	for (gsize i = 0; i < g.dictionaries_len; i++)
+	for (gsize i = 0; i < g.dictionaries->len; i++)
 	{
-		Dictionary *dict = &g.dictionaries[i];
+		Dictionary *dict = g_ptr_array_index (g.dictionaries, i);
 		GtkWidget *dummy = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 		GtkWidget *label = gtk_label_new (dict->name);
 		gtk_notebook_append_page (GTK_NOTEBOOK (g.notebook), dummy, label);
@@ -305,7 +324,5 @@ main (int argc, char *argv[])
 	gtk_widget_grab_focus (g.entry);
 	gtk_widget_show_all (g.window);
 	gtk_main ();
-
-	g_strfreev (filenames);
 	return 0;
 }

src/sdtui.c

@@ -28,13 +28,11 @@
 #include <gio/gio.h>
 #include <pango/pango.h>
 #include <glib/gi18n.h>
-#include <glib/gstdio.h>
 
 #include <unistd.h>
 #include <poll.h>
 #include <errno.h>
 #include <signal.h>
-#include <pwd.h>
 
 #include <termo.h>  // input
 #include <ncurses.h>  // output
@@ -96,94 +94,6 @@ add_read_watch (int fd, GIOFunc func, gpointer user_data)
 	return res;
 }
 
-// At times, GLib even with its sheer size is surprisingly useless,
-// and I need to port some code over from "liberty".
-
-static gchar **
-get_xdg_config_dirs (void)
-{
-	GPtrArray *paths = g_ptr_array_new ();
-	g_ptr_array_add (paths, (gpointer) g_get_user_config_dir ());
-	for (const gchar *const *system = g_get_system_config_dirs ();
-		*system; system++)
-		g_ptr_array_add (paths, (gpointer) *system);
-	g_ptr_array_add (paths, NULL);
-	return (gchar **) g_ptr_array_free (paths, FALSE);
-}
-
-static gchar *
-resolve_relative_filename_generic
-	(gchar **paths, const gchar *tail, const gchar *filename)
-{
-	for (; *paths; paths++)
-	{
-		// As per XDG spec, relative paths are ignored
-		if (**paths != '/')
-			continue;
-
-		gchar *file = g_build_filename (*paths, tail, filename, NULL);
-		GStatBuf st;
-		if (!g_stat (file, &st))
-			return file;
-		g_free (file);
-	}
-	return NULL;
-}
-
-static gchar *
-resolve_relative_config_filename (const gchar *filename)
-{
-	gchar **paths = get_xdg_config_dirs ();
-	gchar *result = resolve_relative_filename_generic
-		(paths, PROJECT_NAME, filename);
-	g_strfreev (paths);
-	return result;
-}
-
-static gchar *
-try_expand_tilde (const gchar *filename)
-{
-	size_t until_slash = strcspn (filename, "/");
-	if (!until_slash)
-		return g_build_filename (g_get_home_dir () ?: "", filename, NULL);
-
-	long buf_len = sysconf (_SC_GETPW_R_SIZE_MAX);
-	if (buf_len < 0)
-		buf_len = 1024;
-	struct passwd pwd, *success = NULL;
-
-	gchar *user = g_strndup (filename, until_slash);
-	gchar *buf = g_malloc (buf_len);
-	while (getpwnam_r (user, &pwd, buf, buf_len, &success) == ERANGE)
-		buf = g_realloc (buf, buf_len <<= 1);
-	g_free (user);
-
-	gchar *result = NULL;
-	if (success)
-		result = g_strdup_printf ("%s%s", pwd.pw_dir, filename + until_slash);
-	g_free (buf);
-	return result;
-}
-
-static gchar *
-resolve_filename (const gchar *filename, gchar *(*relative_cb) (const char *))
-{
-	// Absolute path is absolute
-	if (*filename == '/')
-		return g_strdup (filename);
-
-	// We don't want to use wordexp() for this as it may execute /bin/sh
-	if (*filename == '~')
-	{
-		// Paths to home directories ought to be absolute
-		char *expanded = try_expand_tilde (filename + 1);
-		if (expanded)
-			return expanded;
-		g_debug ("failed to expand the home directory in `%s'", filename);
-	}
-	return relative_cb (filename);
-}
-
 // --- Application -------------------------------------------------------------
 
 #define ATTRIBUTE_TABLE(XX)                               \
@@ -215,7 +125,7 @@ struct attrs
 /// Data relating to one entry within the dictionary.
 typedef struct view_entry               ViewEntry;
 /// Data relating to a dictionary file.
-typedef struct dictionary               Dictionary;
+typedef struct app_dictionary           AppDictionary;
 /// Encloses application data.
 typedef struct application              Application;
 
@@ -226,12 +136,10 @@ struct view_entry
 	GPtrArray * formatting;             ///< chtype * or NULL per definition
 };
 
-struct dictionary
+struct app_dictionary
 {
-	gchar         * name;               ///< Visible identifier
+	Dictionary  super;                  ///< Superclass
 	gsize       name_width;             ///< Visible width of the name
-	gchar         * filename;           ///< Path to the dictionary
-	StardictDict  * dict;               ///< Dictionary
 };
 
 struct application
@@ -243,7 +151,7 @@ struct application
 	gboolean        locale_is_utf8;     ///< The locale is Unicode
 	gboolean        focused;            ///< Whether the terminal has focus
 
-	GArray        * dictionaries;       ///< All loaded dictionaries
+	GPtrArray     * dictionaries;       ///< All loaded AppDictionaries
 
 	StardictDict  * dict;               ///< The current dictionary
 	guint           show_help : 1;      ///< Whether help can be shown
@@ -442,42 +350,6 @@ view_entry_free (ViewEntry *ve)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-static gboolean
-dictionary_load (Dictionary *self, Application *app, GError **e)
-{
-	if (!(self->dict = stardict_dict_new (self->filename, e)))
-		return FALSE;
-
-	if (!self->name)
-	{
-		self->name = g_strdup (stardict_info_get_book_name
-			(stardict_dict_get_info (self->dict)));
-	}
-
-	// Add some padding for decorative purposes
-	gchar *tmp = g_strdup_printf (" %s ", self->name);
-	g_free (self->name);
-	self->name = tmp;
-
-	gunichar *ucs4 = g_utf8_to_ucs4_fast (self->name, -1, NULL);
-	for (gunichar *it = ucs4; *it; it++)
-		self->name_width += app_char_width (app, *it);
-	g_free (ucs4);
-	return TRUE;
-}
-
-static void
-dictionary_free (Dictionary *self)
-{
-	g_free (self->name);
-	g_free (self->filename);
-
-	if (self->dict)
-		g_object_unref (self->dict);
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
 /// Reload view items.
 static void
 app_reload_view (Application *self)
@@ -574,44 +446,32 @@ app_load_config_values (Application *self, GKeyFile *kf)
 			continue;
 
 		// Try to resolve relative paths and expand tildes
-		gchar *resolved = resolve_filename
-			(path, resolve_relative_config_filename);
+		gchar *resolved =
+			resolve_filename (path, resolve_relative_config_filename);
 		if (resolved)
 			g_free (path);
 		else
 			resolved = path;
 
-		Dictionary dict = { .name = g_strdup (*it), .filename = resolved };
-		g_array_append_val (self->dictionaries, dict);
+		AppDictionary *dict = g_malloc0 (sizeof *dict);
+		dict->super.name = g_strdup (*it);
+		dict->super.filename = resolved;
+		g_ptr_array_add (self->dictionaries, dict);
 	}
 	g_strfreev (names);
 }
 
 static void
-app_load_config (Application *self, GError **e)
+app_load_config (Application *self, GError **error)
 {
-	GKeyFile *kf = g_key_file_new ();
-	gchar **paths = get_xdg_config_dirs ();
-
-	// XXX: if there are dashes in the final path component,
-	//   the function tries to replace them with directory separators,
-	//   which is completely undocumented
-	GError *error = NULL;
-	g_key_file_load_from_dirs (kf,
-		PROJECT_NAME G_DIR_SEPARATOR_S PROJECT_NAME ".conf",
-		(const gchar **) paths, NULL, 0, &error);
-	g_strfreev (paths);
-
 	// TODO: proper error handling showing all relevant information;
 	//   we can afford that here since the terminal hasn't been initialized yet
-	if (!error)
-		app_load_config_values (self, kf);
-	else if (error->code == G_KEY_FILE_ERROR_NOT_FOUND)
-		g_error_free (error);
-	else
-		g_propagate_error (e, error);
-
-	g_key_file_free (kf);
+	GKeyFile *key_file = load_project_config_file (error);
+	if (key_file)
+	{
+		app_load_config_values (self, key_file);
+		g_key_file_free (key_file);
+	}
 }
 
 static void
@@ -625,67 +485,29 @@ app_init_attrs (Application *self)
 #undef XX
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
 static gboolean
 app_load_dictionaries (Application *self, GError **e)
 {
-	for (guint i = 0; i < self->dictionaries->len; i++)
-		if (!dictionary_load (&g_array_index (self->dictionaries,
-			Dictionary, i), self, e))
+	if (!load_dictionaries (self->dictionaries, e))
 		return FALSE;
+
+	for (gsize i = 0; i < self->dictionaries->len; i++)
+	{
+		AppDictionary *dict = g_ptr_array_index (self->dictionaries, i);
+
+		// Add some padding for decorative purposes
+		gchar *tmp = g_strdup_printf (" %s ", dict->super.name);
+		g_free (dict->super.name);
+		dict->super.name = tmp;
+
+		gunichar *ucs4 = g_utf8_to_ucs4_fast (dict->super.name, -1, NULL);
+		for (gunichar *it = ucs4; *it; it++)
+			dict->name_width += app_char_width (self, *it);
+		g_free (ucs4);
+	}
 	return TRUE;
 }
 
-// Parallelize dictionary loading if possible, because of collation reindexing
-#if GLIB_CHECK_VERSION (2, 36, 0)
-struct load_ctx
-{
-	Application *self;                  ///< Application context
-	GAsyncQueue *error_queue;           ///< Errors
-};
-
-static void
-app_load_worker (gpointer data, gpointer user_data)
-{
-	struct load_ctx *ctx = user_data;
-	GError *e = NULL;
-	dictionary_load (&g_array_index (ctx->self->dictionaries, Dictionary,
-		GPOINTER_TO_UINT (data) - 1), ctx->self, &e);
-	if (e)
-		g_async_queue_push (ctx->error_queue, e);
-}
-
-static gboolean
-app_load_dictionaries_parallel (Application *self, GError **e)
-{
-	struct load_ctx ctx;
-	GThreadPool *pool = g_thread_pool_new (app_load_worker, &ctx,
-		g_get_num_processors (), TRUE, NULL);
-	if G_UNLIKELY (!g_thread_pool_get_num_threads (pool))
-	{
-		g_thread_pool_free (pool, TRUE, TRUE);
-		return app_load_dictionaries (self, e);
-	}
-
-	ctx.self = self;
-	ctx.error_queue = g_async_queue_new_full ((GDestroyNotify) g_error_free);
-	for (guint i = 0; i < self->dictionaries->len; i++)
-		g_thread_pool_push (pool, GUINT_TO_POINTER (i + 1), NULL);
-
-	g_thread_pool_free (pool, FALSE, TRUE);
-
-	gboolean result = TRUE;
-	if ((*e = g_async_queue_try_pop (ctx.error_queue)))
-		result = FALSE;
-
-	g_async_queue_unref (ctx.error_queue);
-	return result;
-}
-
-#define app_load_dictionaries app_load_dictionaries_parallel
-#endif  // GLib >= 2.36
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
 /// Initialize the application core.
@@ -727,9 +549,8 @@ app_init (Application *self, char **filenames)
 	self->focused = TRUE;
 
 	app_init_attrs (self);
-	self->dictionaries = g_array_new (FALSE, TRUE, sizeof (Dictionary));
-	g_array_set_clear_func
-		(self->dictionaries, (GDestroyNotify) dictionary_free);
+	self->dictionaries =
+		g_ptr_array_new_with_free_func ((GDestroyNotify) dictionary_destroy);
 
 	GError *error = NULL;
 	app_load_config (self, &error);
@@ -744,11 +565,12 @@ app_init (Application *self, char **filenames)
 	// Dictionaries given on the command line override the configuration
 	if (*filenames)
 	{
-		g_array_set_size (self->dictionaries, 0);
+		g_ptr_array_set_size (self->dictionaries, 0);
 		while (*filenames)
 		{
-			Dictionary dict = { .filename = g_strdup (*filenames++) };
-			g_array_append_val (self->dictionaries, dict);
+			AppDictionary *dict = g_malloc0 (sizeof *dict);
+			dict->super.filename = g_strdup (*filenames++);
+			g_ptr_array_add (self->dictionaries, dict);
 		}
 	}
 
@@ -763,7 +585,8 @@ app_init (Application *self, char **filenames)
 			"the configuration or on the command line"));
 		exit (EXIT_FAILURE);
 	}
-	self->dict = g_array_index (self->dictionaries, Dictionary, 0).dict;
+	self->dict = ((AppDictionary *)
+		g_ptr_array_index (self->dictionaries, 0))->super.dict;
 	app_reload_view (self);
 }
 
@@ -819,7 +642,7 @@ app_destroy (Application *self)
 	g_ptr_array_free (self->entries, TRUE);
 	g_free (self->search_label);
 	g_array_free (self->input, TRUE);
-	g_array_free (self->dictionaries, TRUE);
+	g_ptr_array_free (self->dictionaries, TRUE);
 
 	g_iconv_close (self->ucs4_to_locale);
 }
@@ -1039,7 +862,7 @@ app_redraw_top (Application *self)
 
 	for (guint i = 0; i < self->dictionaries->len; i++)
 	{
-		Dictionary *dict = &g_array_index (self->dictionaries, Dictionary, i);
+		Dictionary *dict = g_ptr_array_index (self->dictionaries, i);
 		row_buffer_append (&buf, dict->name,
 			APP_ATTR_IF (self->dictionaries->len > 1
 				&& self->dict == dict->dict, ACTIVE, HEADER));
@@ -1514,7 +1337,7 @@ app_goto_dictionary (Application *self, guint n)
 	if (n >= self->dictionaries->len)
 		return FALSE;
 
-	Dictionary *dict = &g_array_index (self->dictionaries, Dictionary, n);
+	Dictionary *dict = g_ptr_array_index (self->dictionaries, n);
 	self->dict = dict->dict;
 	app_search_for_entry (self);
 	app_redraw_top (self);
@@ -1525,13 +1348,13 @@ app_goto_dictionary (Application *self, guint n)
 static gboolean
 app_goto_dictionary_delta (Application *self, gint n)
 {
-	GArray *dicts = self->dictionaries;
+	GPtrArray *dicts = self->dictionaries;
 	if (dicts->len <= 1)
 		return FALSE;
 
 	guint i = 0;
 	while (i < dicts->len &&
-		g_array_index (dicts, Dictionary, i).dict != self->dict)
+		((Dictionary *) g_ptr_array_index (dicts, i))->dict != self->dict)
 		i++;
 
 	return app_goto_dictionary (self, (i + dicts->len + n) % dicts->len);
@@ -1962,10 +1785,10 @@ app_process_left_mouse_click (Application *self, int line, int column)
 		if (column < indent)
 			return;
 
-		Dictionary *dicts = (Dictionary *) self->dictionaries->data;
 		for (guint i = 0; i < self->dictionaries->len; i++)
 		{
-			if (column < (indent += dicts[i].name_width))
+			AppDictionary *dict = g_ptr_array_index (self->dictionaries, i);
+			if (column < (indent += dict->name_width))
 			{
 				app_goto_dictionary (self, i);
 				return;

src/utils.c

@@ -19,10 +19,14 @@
 #include <glib.h>
 #include <glib/gprintf.h>
 #include <gio/gio.h>
+#include <glib/gstdio.h>
+
 #include <stdlib.h>
 #include <errno.h>
 #include <stdarg.h>
 
+#include <pwd.h>
+
 #include "config.h"
 #include "utils.h"
 
@@ -105,3 +109,198 @@ fatal (const gchar *format, ...)
 	exit (EXIT_FAILURE);
 	va_end (ap);
 }
+
+// At times, GLib even with its sheer size is surprisingly useless,
+// and I need to port some code over from "liberty".
+
+static const gchar **
+get_xdg_config_dirs (void)
+{
+	GPtrArray *paths = g_ptr_array_new ();
+	g_ptr_array_add (paths, (gpointer) g_get_user_config_dir ());
+	for (const gchar *const *system = g_get_system_config_dirs ();
+		*system; system++)
+		g_ptr_array_add (paths, (gpointer) *system);
+	g_ptr_array_add (paths, NULL);
+	return (const gchar **) g_ptr_array_free (paths, FALSE);
+}
+
+gchar *
+resolve_relative_filename_generic
+	(const gchar **paths, const gchar *tail, const gchar *filename)
+{
+	for (; *paths; paths++)
+	{
+		// As per XDG spec, relative paths are ignored
+		if (**paths != '/')
+			continue;
+
+		gchar *file = g_build_filename (*paths, tail, filename, NULL);
+		GStatBuf st;
+		if (!g_stat (file, &st))
+			return file;
+		g_free (file);
+	}
+	return NULL;
+}
+
+gchar *
+resolve_relative_config_filename (const gchar *filename)
+{
+	const gchar **paths = get_xdg_config_dirs ();
+	gchar *result =
+		resolve_relative_filename_generic (paths, PROJECT_NAME, filename);
+	g_free (paths);
+	return result;
+}
+
+static gchar *
+try_expand_tilde (const gchar *filename)
+{
+	size_t until_slash = strcspn (filename, "/");
+	if (!until_slash)
+		return g_build_filename (g_get_home_dir () ?: "", filename, NULL);
+
+	long buf_len = sysconf (_SC_GETPW_R_SIZE_MAX);
+	if (buf_len < 0)
+		buf_len = 1024;
+	struct passwd pwd, *success = NULL;
+
+	gchar *user = g_strndup (filename, until_slash);
+	gchar *buf = g_malloc (buf_len);
+	while (getpwnam_r (user, &pwd, buf, buf_len, &success) == ERANGE)
+		buf = g_realloc (buf, buf_len <<= 1);
+	g_free (user);
+
+	gchar *result = NULL;
+	if (success)
+		result = g_strdup_printf ("%s%s", pwd.pw_dir, filename + until_slash);
+	g_free (buf);
+	return result;
+}
+
+gchar *
+resolve_filename (const gchar *filename, gchar *(*relative_cb) (const char *))
+{
+	// Absolute path is absolute
+	if (*filename == '/')
+		return g_strdup (filename);
+
+	// We don't want to use wordexp() for this as it may execute /bin/sh
+	if (*filename == '~')
+	{
+		// Paths to home directories ought to be absolute
+		char *expanded = try_expand_tilde (filename + 1);
+		if (expanded)
+			return expanded;
+		g_debug ("failed to expand the home directory in `%s'", filename);
+	}
+	return relative_cb (filename);
+}
+
+GKeyFile *
+load_project_config_file (GError **error)
+{
+	GKeyFile *key_file = g_key_file_new ();
+	const gchar **paths = get_xdg_config_dirs ();
+	GError *e = NULL;
+
+	// XXX: if there are dashes in the final path component,
+	//   the function tries to replace them with directory separators,
+	//   which is completely undocumented
+	g_key_file_load_from_dirs (key_file,
+		PROJECT_NAME G_DIR_SEPARATOR_S PROJECT_NAME ".conf",
+		paths, NULL, 0, &e);
+	g_free (paths);
+	if (!e)
+		return key_file;
+
+	if (e->code == G_KEY_FILE_ERROR_NOT_FOUND)
+		g_error_free (e);
+	else
+		g_propagate_error (error, e);
+
+	g_key_file_free (key_file);
+	return NULL;
+}
+
+// --- Loading -----------------------------------------------------------------
+
+void
+dictionary_destroy (Dictionary *self)
+{
+	g_free (self->name);
+	g_free (self->filename);
+
+	if (self->dict)
+		g_object_unref (self->dict);
+
+	g_free (self);
+}
+
+static gboolean
+dictionary_load (Dictionary *self, GError **e)
+{
+	if (!(self->dict = stardict_dict_new (self->filename, e)))
+		return FALSE;
+
+	if (!self->name)
+	{
+		self->name = g_strdup (stardict_info_get_book_name
+			(stardict_dict_get_info (self->dict)));
+	}
+	return TRUE;
+}
+
+static gboolean
+load_dictionaries_sequentially (GPtrArray *dictionaries, GError **e)
+{
+	for (guint i = 0; i < dictionaries->len; i++)
+		if (!dictionary_load (g_ptr_array_index (dictionaries, i), e))
+			return FALSE;
+	return TRUE;
+}
+
+// Parallelize dictionary loading if possible, because of collation reindexing
+#if GLIB_CHECK_VERSION (2, 36, 0)
+static void
+load_worker (gpointer data, gpointer user_data)
+{
+	GError *e = NULL;
+	dictionary_load (data, &e);
+	if (e)
+		g_async_queue_push (user_data, e);
+}
+
+gboolean
+load_dictionaries (GPtrArray *dictionaries, GError **e)
+{
+	GAsyncQueue *error_queue =
+		g_async_queue_new_full ((GDestroyNotify) g_error_free);
+	GThreadPool *pool = g_thread_pool_new (load_worker, error_queue,
+		g_get_num_processors (), TRUE, NULL);
+	if G_UNLIKELY (!g_thread_pool_get_num_threads (pool))
+	{
+		g_thread_pool_free (pool, TRUE, TRUE);
+		g_async_queue_unref (error_queue);
+		return load_dictionaries_sequentially (dictionaries, e);
+	}
+
+	for (guint i = 0; i < dictionaries->len; i++)
+		g_thread_pool_push (pool, g_ptr_array_index (dictionaries, i), NULL);
+	g_thread_pool_free (pool, FALSE, TRUE);
+
+	gboolean result = TRUE;
+	if ((*e = g_async_queue_try_pop (error_queue)))
+		result = FALSE;
+
+	g_async_queue_unref (error_queue);
+	return result;
+}
+#else  // GLib < 2.36
+gboolean
+load_dictionaries (GPtrArray *dictionaries, GError **e)
+{
+	return load_dictionaries_sequentially (dictionaries, e);
+}
+#endif  // GLib < 2.36

src/utils.h

@@ -1,7 +1,7 @@
 /*
  * utils.h: miscellaneous utilities
  *
- * Copyright (c) 2013 - 2020, Přemysl Eric Janouch <p@janouch.name>
+ * Copyright (c) 2013 - 2021, Přemysl Eric Janouch <p@janouch.name>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted.
@@ -19,6 +19,11 @@
 #ifndef UTILS_H
 #define UTILS_H
 
+#include <glib.h>
+#include <gio/gio.h>
+
+#include "stardict.h"
+
 /// After this statement, the element has been found and its index is stored
 /// in the variable "imid".
 #define BINARY_SEARCH_BEGIN(max, compare)                                     \
@@ -43,4 +48,25 @@ gchar *stream_read_string (GDataInputStream *dis, GError **error);
 gboolean xstrtoul (unsigned long *out, const char *s, int base);
 void fatal (const gchar *format, ...) G_GNUC_PRINTF (1, 2) G_GNUC_NORETURN;
 
+gchar *resolve_relative_filename_generic
+	(const gchar **paths, const gchar *tail, const gchar *filename);
+gchar *resolve_relative_config_filename (const gchar *filename);
+gchar *resolve_filename
+	(const gchar *filename, gchar *(*relative_cb) (const char *));
+GKeyFile *load_project_config_file (GError **error);
+
+// --- Loading -----------------------------------------------------------------
+
+typedef struct dictionary Dictionary;
+
+struct dictionary
+{
+	gchar        *filename;          ///< Path to the dictionary
+	StardictDict *dict;              ///< StarDict dictionary data
+	gchar        *name;              ///< Name to show
+};
+
+void dictionary_destroy (Dictionary *self);
+gboolean load_dictionaries (GPtrArray *dictionaries, GError **e);
+
 #endif  // ! UTILS_H