/*
* e-module.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) version 3.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with the program; if not, see <http://www.gnu.org/licenses/>
*
*
* Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
*
*/
/**
* SECTION: e-module
* @short_description: a module loader
* @include: e-util/e-module.h
**/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "e-module.h"
#include <glib/gi18n.h>
/* This is the symbol we call when loading a module. */
#define LOAD_SYMBOL "e_module_load"
/* This is the symbol we call when unloading a module. */
#define UNLOAD_SYMBOL "e_module_unload"
struct _EModulePrivate {
GModule *module;
gchar *filename;
void (*load) (GTypeModule *type_module);
void (*unload) (GTypeModule *type_module);
};
enum {
PROP_0,
PROP_FILENAME
};
G_DEFINE_TYPE (
EModule,
e_module,
G_TYPE_TYPE_MODULE)
static void
module_set_filename (EModule *module,
const gchar *filename)
{
g_return_if_fail (module->priv->filename == NULL);
module->priv->filename = g_strdup (filename);
}
static void
module_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
switch (property_id) {
case PROP_FILENAME:
module_set_filename (
E_MODULE (object),
g_value_get_string (value));
return;
}
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}
static void
module_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
switch (property_id) {
case PROP_FILENAME:
g_value_set_string (
value, e_module_get_filename (
E_MODULE (object)));
return;
}
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}
static void
module_finalize (GObject *object)
{
EModulePrivate *priv;
priv = E_MODULE (object)->priv;
g_free (priv->filename);
/* Chain up to parent's finalize() method. */
G_OBJECT_CLASS (e_module_parent_class)->finalize (object);
}
static gboolean
module_load (GTypeModule *type_module)
{
EModulePrivate *priv;
gpointer symbol;
priv = E_MODULE (type_module)->priv;
g_return_val_if_fail (priv->filename != NULL, FALSE);
priv->module = g_module_open (priv->filename, 0);
if (priv->module == NULL)
goto fail;
if (!g_module_symbol (priv->module, LOAD_SYMBOL, &symbol))
goto fail;
priv->load = symbol;
if (!g_module_symbol (priv->module, UNLOAD_SYMBOL, &symbol))
goto fail;
priv->unload = symbol;
priv->load (type_module);
/* XXX This is a Band-Aid for a design flaw in EExtension. If the
* "extensible_type" member of EExtensionClass is set to a GType
* that hasn't already been registered, then when the extension's
* module is unloaded the GType registration that was triggered
* by setting "extensible_type" will be invalidated and cause
* Evolution to malfunction when the module is loaded again.
*
* Extension modules get loaded and unloaded repeatedly by
* e_extensible_load_extensions(), which temporarily references
* all extension classes and picks out the ones it needs for a
* given EExtensible instance based on the "extensible_type"
* class member.
*
* Making the module resident prevents the aforementioned GType
* registration from being invalidated when the extension class
* is unreferenced.
*/
g_module_make_resident (priv->module);
return TRUE;
fail:
g_warning ("%s", g_module_error ());
if (priv->module != NULL)
g_module_close (priv->module);
return FALSE;
}
static void
module_unload (GTypeModule *type_module)
{
EModulePrivate *priv;
priv = E_MODULE (type_module)->priv;
priv->unload (type_module);
g_module_close (priv->module);
priv->module = NULL;
priv->load = NULL;
priv->unload = NULL;
}
static void
e_module_class_init (EModuleClass *class)
{
GObjectClass *object_class;
GTypeModuleClass *type_module_class;
g_type_class_add_private (class, sizeof (EModulePrivate));
object_class = G_OBJECT_CLASS (class);
object_class->set_property = module_set_property;
object_class->get_property = module_get_property;
object_class->finalize = module_finalize;
type_module_class = G_TYPE_MODULE_CLASS (class);
type_module_class->load = module_load;
type_module_class->unload = module_unload;
/**
* EModule:filename
*
* The filename of the module.
**/
g_object_class_install_property (
object_class,
PROP_FILENAME,
g_param_spec_string (
"filename",
"Filename",
"The filename of the module",
NULL,
G_PARAM_READWRITE |
G_PARAM_CONSTRUCT_ONLY));
}
static void
e_module_init (EModule *module)
{
module->priv = G_TYPE_INSTANCE_GET_PRIVATE (
module, E_TYPE_MODULE, EModulePrivate);
}
/**
* e_module_new:
* @filename: filename of the shared library module
*
* Creates a new #EModule that will load the specific shared library
* when in use.
*
* Returns: a new #EModule for @filename
**/
EModule *
e_module_new (const gchar *filename)
{
g_return_val_if_fail (filename != NULL, NULL);
return g_object_new (E_TYPE_MODULE, "filename", filename, NULL);
}
/**
* e_module_get_filename:
* @module: an #EModule
*
* Returns the filename of the shared library for @module. The
* string is owned by @module and should not be modified or freed.
*
* Returns: the filename for @module
**/
const gchar *
e_module_get_filename (EModule *module)
{
g_return_val_if_fail (E_IS_MODULE (module), NULL);
return module->priv->filename;
}
/**
* e_module_load_all_in_directory:
* @dirname: pathname for a directory containing modules to load
*
* Loads all the modules in the specified directory into memory. If
* you want to unload them (enabling on-demand loading) you must call
* g_type_module_unuse() on all the modules. Free the returned list
* with g_list_free().
*
* Returns: a list of #EModules loaded from @dirname
**/
GList *
e_module_load_all_in_directory (const gchar *dirname)
{
GDir *dir;
const gchar *basename;
GList *loaded_modules = NULL;
GError *error = NULL;
g_return_val_if_fail (dirname != NULL, NULL);
if (!g_module_supported ())
return NULL;
dir = g_dir_open (dirname, 0, &error);
if (dir == NULL) {
g_warning ("%s", error->message);
g_error_free (error);
return NULL;
}
while ((basename = g_dir_read_name (dir)) != NULL) {
EModule *module;
gchar *filename;
if (!g_str_has_suffix (basename, "." G_MODULE_SUFFIX))
continue;
filename = g_build_filename (dirname, basename, NULL);
module = e_module_new (filename);
if (!g_type_module_use (G_TYPE_MODULE (module))) {
g_printerr ("Failed to load module: %s\n", filename);
g_object_unref (module);
g_free (filename);
continue;
}
g_free (filename);
loaded_modules = g_list_prepend (loaded_modules, module);
}
g_dir_close (dir);
return loaded_modules;
}
