path: root/lib/ephy-shlib-loader.c

/*
 *  Copyright (C) 2003 Marco Pesenti Gritti
 *  Copyright (C) 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 *  $Id$
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "ephy-shlib-loader.h"
#include "ephy-loader.h"
#include "ephy-module.h"
#include "ephy-debug.h"

#include <string.h>

#define DATA_KEY "EphyShlibLoader::LoaderData"

typedef struct
{
    EphyModule *module;
    GObject *object;
} LoaderData;

static GQuark library_quark = 0;

#define EPHY_SHLIB_LOADER_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE ((object), EPHY_TYPE_SHLIB_LOADER, EphyShlibLoaderPrivate))

struct _EphyShlibLoaderPrivate
{
    GSList *data;
};

static void ephy_shlib_loader_class_init (EphyShlibLoaderClass *klass);
static void ephy_shlib_loader_iface_init (EphyLoaderIface *iface);
static void ephy_shlib_loader_init    (EphyShlibLoader *loader);

static GObjectClass *parent_class = NULL;

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

    if (G_UNLIKELY (type == 0))
    {
        static const GTypeInfo our_info =
        {
            sizeof (EphyShlibLoaderClass),
            NULL, /* base_init */
            NULL, /* base_finalize */
            (GClassInitFunc) ephy_shlib_loader_class_init,
            NULL,
            NULL, /* class_data */
            sizeof (EphyShlibLoader),
            0, /* n_preallocs */
            (GInstanceInitFunc) ephy_shlib_loader_init
        };

        static const GInterfaceInfo loader_info =
        {
            (GInterfaceInitFunc) ephy_shlib_loader_iface_init,
            NULL,
            NULL
        };

        type = g_type_register_static (G_TYPE_OBJECT,
                           "EphyShlibLoader",
                           &our_info, 0);

        g_type_add_interface_static (type,
                         EPHY_TYPE_LOADER,
                         &loader_info);
    }

    return type;
}

static void
free_loader_data (LoaderData *data)
{
    g_return_if_fail (data != NULL);

    /* data->module must NOT be unreffed! */

    if (data->object != NULL)
    {
        g_object_unref (data->object);
    }

    g_free (data);
}

static void
ephy_shlib_loader_init (EphyShlibLoader *loader)
{
    loader->priv = EPHY_SHLIB_LOADER_GET_PRIVATE (loader);

    LOG ("EphyShlibLoader initialising")
}

static void
ephy_shlib_loader_finalize (GObject *object)
{
    EphyShlibLoader *loader = EPHY_SHLIB_LOADER (object);

    LOG ("EphyShlibLoader finalising")

    g_slist_foreach (loader->priv->data, (GFunc) free_loader_data, NULL);
    g_slist_free (loader->priv->data);

    parent_class->finalize (object);
}

static int
find_library (const LoaderData *data,
          const char *library)
{
    return strcmp (ephy_module_get_path (data->module), library);
}

static int
find_object (const LoaderData *data,
         const GObject *object)
{
    return data->object != object;
}

static gboolean
idle_unref (GObject *object)
{
    g_object_unref (object);

    return FALSE;
}

static GObject *
impl_get_object (EphyLoader *eloader,
         GData **attributes)
{
    EphyShlibLoader *loader = EPHY_SHLIB_LOADER (eloader);
    GSList *l;
    LoaderData *data = NULL;
    const char *library;

    library = g_datalist_id_get_data (attributes, library_quark);
    if (library == NULL)
    {
        g_warning ("NULL library name!\n");
        return NULL;
    }

    l = g_slist_find_custom (loader->priv->data, library,
                (GCompareFunc) find_library);

    if (l != NULL)
    {
        data = l->data;
        g_return_val_if_fail (data != NULL, NULL);

        if (data->object != NULL)
        {
            return g_object_ref (data->object);
        }
    }
    else
    {
        data = g_new0 (LoaderData, 1);
        loader->priv->data = g_slist_prepend (loader->priv->data, data);
    }

    if (data->module == NULL)
    {
        data->module = ephy_module_new (library);
    }

    g_return_val_if_fail (data->object == NULL, data->object);

    if (g_type_module_use (G_TYPE_MODULE (data->module)) == FALSE)
    {
        g_warning ("Could not load extension file at %s\n",
               ephy_module_get_path (data->module));
        return NULL;
    }

    data->object = ephy_module_new_object (data->module);

    g_type_module_unuse (G_TYPE_MODULE (data->module));

    if (data->object != NULL)
    {
        g_object_set_data (G_OBJECT (data->object), DATA_KEY, data);
    }

    return data->object;
}

static void
impl_release_object (EphyLoader *eloader,
             GObject *object)
{
    EphyShlibLoader *loader = EPHY_SHLIB_LOADER (eloader);
    GSList *l;
    LoaderData *data;

    l = g_slist_find_custom (loader->priv->data, object,
                (GCompareFunc) find_object);
    g_return_if_fail (l != NULL);
    data = l->data;

    /* FIXME: should we consider those extensions broken?
     * Only unref the extension in the idle loop; if the extension has its
     * own functions queued in the idle loop, the functions must exist in
     * memory before being called.
     */
    g_idle_add ((GSourceFunc) idle_unref, data->object);
    data->object = NULL;
}

static void
ephy_shlib_loader_iface_init (EphyLoaderIface *iface)
{
    iface->type = "shlib";
    iface->get_object = impl_get_object;
    iface->release_object = impl_release_object;
}

static void
ephy_shlib_loader_class_init (EphyShlibLoaderClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);

    parent_class = g_type_class_peek_parent (klass);

    object_class->finalize = ephy_shlib_loader_finalize;

    g_type_class_add_private (object_class, sizeof (EphyShlibLoaderPrivate));

    library_quark = g_quark_from_string ("library");
}