path: root/lib/ephy-module.c

/*
 *  Copyright © 2003 Marco Pesenti Gritti
 *  Copyright © 2003, 2004 Christian Persch
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 *  $Id$
 */

#include "config.h"

#include "ephy-module.h"
#include "ephy-file-helpers.h"
#include "ephy-debug.h"

#include <gmodule.h>

typedef struct _EphyModuleClass EphyModuleClass;

struct _EphyModuleClass
{
    GTypeModuleClass parent_class;
};

struct _EphyModule
{
    GTypeModule parent_instance;

    GModule *library;

    char *path;
    GType type;
    guint resident : 1;
};

typedef GType (*EphyModuleRegisterFunc) (GTypeModule *);

static void ephy_module_init        (EphyModule *action);
static void ephy_module_class_init  (EphyModuleClass *class);

static GObjectClass *parent_class = NULL;

GType
ephy_module_get_type (void)
{
    static GType type = 0;

    if (G_UNLIKELY (type == 0))
    {
        const GTypeInfo type_info =
        {
            sizeof (EphyModuleClass),
            (GBaseInitFunc) NULL,
            (GBaseFinalizeFunc) NULL,
            (GClassInitFunc) ephy_module_class_init,
            (GClassFinalizeFunc) NULL,
            NULL,
            sizeof (EphyModule),
            0, /* n_preallocs */
            (GInstanceInitFunc) ephy_module_init,
        };

        type = g_type_register_static (G_TYPE_TYPE_MODULE,
                           "EphyModule",
                           &type_info, 0);
    }

    return type;
}

static gboolean
ephy_module_load (GTypeModule *gmodule)
{
    EphyModule *module = EPHY_MODULE (gmodule);
    EphyModuleRegisterFunc register_func;
    gboolean is_absolute;
    GModuleFlags flags = G_MODULE_BIND_LOCAL | G_MODULE_BIND_LAZY;

    LOG ("Loading %s", module->path);

    /* In debug builds, we bind immediately so we can find missing
     * symbols in extensions on load; otherwise we bind lazily
     */
#ifdef GNOME_ENABLE_DEBUG
    flags &= ~G_MODULE_BIND_LAZY;
#endif

    is_absolute = g_path_is_absolute (module->path);

    if (module->library == NULL && ! is_absolute)
    {
        char *path = g_build_filename (EXTENSIONS_DIR, module->path, NULL);

        module->library = g_module_open (path, flags);

        g_free (path);
    }

    if (module->library == NULL && ! is_absolute)
    {
        char *path = g_build_filename (ephy_dot_dir(), "extensions", module->path, NULL);
        
        module->library = g_module_open (path, flags);
 
        g_free (path);
    }

    if (module->library == NULL)
    {
        module->library = g_module_open (module->path, flags);
    }

    if (module->library == NULL)
    {
        g_warning ("%s", g_module_error());

        return FALSE;
    }

    /* extract symbols from the lib */
    if (!g_module_symbol (module->library, "register_module",
                  (void *) &register_func))
    {
        g_warning ("%s", g_module_error());
        g_module_close (module->library);

        return FALSE;
    }

    /* symbol can still be NULL even though g_module_symbol returned TRUE */
    if (!register_func)
    {
        g_warning ("Symbol 'register_module' is NULL!");
        g_module_close (module->library);

        return FALSE;
    }

    module->type = register_func (gmodule);

    if (module->type == 0)
    {
        return FALSE;
    }

    if (module->resident)
    {
        g_module_make_resident (module->library);
    }

    return TRUE;
}

static void
ephy_module_unload (GTypeModule *gmodule)
{
    EphyModule *module = EPHY_MODULE (gmodule);

    LOG ("Unloading %s", module->path);

    g_module_close (module->library);

    module->library = NULL;
    module->type = 0;
}

const char *
ephy_module_get_path (EphyModule *module)
{
    g_return_val_if_fail (EPHY_IS_MODULE (module), NULL);

    return module->path;
}

GObject *
ephy_module_new_object (EphyModule *module)
{
    LOG ("Creating object of type %s", g_type_name (module->type));

    if (module->type == 0)
    {
        return NULL;
    }

    return g_object_new (module->type, NULL);
}

static void
ephy_module_init (EphyModule *module)
{
    LOG ("EphyModule %p initialising", module);
}

static void
ephy_module_finalize (GObject *object)
{
    EphyModule *module = EPHY_MODULE (object);

    LOG ("EphyModule %p finalising", module);

    g_free (module->path);

    G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
ephy_module_class_init (EphyModuleClass *class)
{
    GObjectClass *object_class = G_OBJECT_CLASS (class);
    GTypeModuleClass *module_class = G_TYPE_MODULE_CLASS (class);

    parent_class = (GObjectClass *) g_type_class_peek_parent (class);

    object_class->finalize = ephy_module_finalize;

    module_class->load = ephy_module_load;
    module_class->unload = ephy_module_unload;
}

EphyModule *
ephy_module_new (const char *path,
         gboolean resident)
{
    EphyModule *result;

    if (path == NULL || path[0] == '\0')
    {
        return NULL;
    }

    result = g_object_new (EPHY_TYPE_MODULE, NULL);

    g_type_module_set_name (G_TYPE_MODULE (result), path);
    result->path = g_strdup (path);
    result->resident = resident != FALSE;

    return result;
}