pygi-cache.c

/* -*- Mode: C; c-basic-offset: 4 -*-
 * vim: tabstop=4 shiftwidth=4 expandtab
 *
 * Copyright (C) 2011 John (J5) Palmieri <johnp@redhat.com>
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 * USA
 */

#include "pygi-info.h"
#include "pygi-cache.h"
#include "pygi-marshal-to-py.h"
#include "pygi-marshal-from-py.h"
#include "pygi-marshal-cleanup.h"
#include "pygi-type.h"
#include <girepository.h>

PyGIArgCache * _arg_cache_new (GITypeInfo *type_info,
                               PyGICallableCache *callable_cache,
                               GIArgInfo *arg_info,
                               GITransfer transfer,
                               PyGIDirection direction,
                               gssize c_arg_index,
                               gssize py_arg_index);

PyGIArgCache * _arg_cache_new_for_interface (GIInterfaceInfo *iface_info,
                                             PyGICallableCache *callable_cache,
                                             GIArgInfo *arg_info,
                                             GITransfer transfer,
                                             PyGIDirection direction,
                                             gssize c_arg_index,
                                             gssize py_arg_index);

/* cleanup */
static void
_pygi_arg_cache_free (PyGIArgCache *cache)
{
    if (cache == NULL)
        return;

    if (cache->type_info != NULL)
        g_base_info_unref ( (GIBaseInfo *)cache->type_info);
    if (cache->destroy_notify)
        cache->destroy_notify (cache);
    else
        g_slice_free (PyGIArgCache, cache);
}

static void
_interface_cache_free_func (PyGIInterfaceCache *cache)
{
    if (cache != NULL) {
        Py_XDECREF (cache->py_type);
        if (cache->type_name != NULL)
            g_free (cache->type_name);
        if (cache->interface_info != NULL)
            g_base_info_unref ( (GIBaseInfo *)cache->interface_info);
        g_slice_free (PyGIInterfaceCache, cache);
    }
}

static void
_hash_cache_free_func (PyGIHashCache *cache)
{
    if (cache != NULL) {
        _pygi_arg_cache_free (cache->key_cache);
        _pygi_arg_cache_free (cache->value_cache);
        g_slice_free (PyGIHashCache, cache);
    }
}

static void
_sequence_cache_free_func (PyGISequenceCache *cache)
{
    if (cache != NULL) {
        _pygi_arg_cache_free (cache->item_cache);
        g_slice_free (PyGISequenceCache, cache);
    }
}

static void
_callback_cache_free_func (PyGICallbackCache *cache)
{
    if (cache != NULL) {
        if (cache->interface_info != NULL)
            g_base_info_unref ( (GIBaseInfo *)cache->interface_info);

        g_slice_free (PyGICallbackCache, cache);
    }
}

void
_pygi_callable_cache_free (PyGICallableCache *cache)
{
    if (cache == NULL)
        return;

    g_slist_free (cache->to_py_args);
    g_slist_free (cache->arg_name_list);
    g_hash_table_destroy (cache->arg_name_hash);
    g_ptr_array_unref (cache->args_cache);

    if (cache->return_cache != NULL)
        _pygi_arg_cache_free (cache->return_cache);

    g_slice_free (PyGICallableCache, cache);
}

/* cache generation */

static PyGIInterfaceCache *
_interface_cache_new (GIInterfaceInfo *iface_info)
{
    PyGIInterfaceCache *ic;

    ic = g_slice_new0 (PyGIInterfaceCache);
    ( (PyGIArgCache *)ic)->destroy_notify = (GDestroyNotify)_interface_cache_free_func;
    ic->g_type = g_registered_type_info_get_g_type ( (GIRegisteredTypeInfo *)iface_info);
    ic->py_type = _pygi_type_import_by_gi_info ( (GIBaseInfo *) iface_info);

    if (ic->py_type == NULL)
        return NULL;

    ic->type_name = _pygi_g_base_info_get_fullname (iface_info);
    return ic;
}

static PyGISequenceCache *
_sequence_cache_new (GITypeInfo *type_info,
                     GIDirection direction,
                     GITransfer transfer,
                     gssize child_offset)
{
    PyGISequenceCache *sc;
    GITypeInfo *item_type_info;
    GITransfer item_transfer;

    sc = g_slice_new0 (PyGISequenceCache);
    ( (PyGIArgCache *)sc)->destroy_notify = (GDestroyNotify)_sequence_cache_free_func;

    sc->is_zero_terminated = g_type_info_is_zero_terminated (type_info);
    sc->fixed_size = g_type_info_get_array_fixed_size (type_info);
    sc->len_arg_index = g_type_info_get_array_length (type_info);
    if (sc->len_arg_index >= 0)
        sc->len_arg_index += child_offset;

    item_type_info = g_type_info_get_param_type (type_info, 0);

    item_transfer =
        transfer == GI_TRANSFER_CONTAINER ? GI_TRANSFER_NOTHING : transfer;

    sc->item_cache = _arg_cache_new (item_type_info,
                                     NULL,
                                     NULL,
                                     item_transfer,
                                     direction,
                                     0, 0);

    if (sc->item_cache == NULL) {
        _pygi_arg_cache_free ( (PyGIArgCache *)sc);
        return NULL;
    }

    sc->item_size = _pygi_g_type_info_size (item_type_info);
    g_base_info_unref ( (GIBaseInfo *)item_type_info);

    return sc;
}
static PyGIHashCache *
_hash_cache_new (GITypeInfo *type_info,
                 GIDirection direction,
                 GITransfer transfer)
{
    PyGIHashCache *hc;
    GITypeInfo *key_type_info;
    GITypeInfo *value_type_info;
    GITransfer item_transfer;

    hc = g_slice_new0 (PyGIHashCache);
    ( (PyGIArgCache *)hc)->destroy_notify = (GDestroyNotify)_hash_cache_free_func;
    key_type_info = g_type_info_get_param_type (type_info, 0);
    value_type_info = g_type_info_get_param_type (type_info, 1);

    item_transfer =
        transfer == GI_TRANSFER_CONTAINER ? GI_TRANSFER_NOTHING : transfer;

    hc->key_cache = _arg_cache_new (key_type_info,
                                    NULL,
                                    NULL,
                                    item_transfer,
                                    direction,
                                    0, 0);

    if (hc->key_cache == NULL) {
        _pygi_arg_cache_free ( (PyGIArgCache *)hc);
        return NULL;
    }

    hc->value_cache = _arg_cache_new (value_type_info,
                                      NULL,
                                      NULL,
                                      item_transfer,
                                      direction,
                                      0, 0);

    if (hc->value_cache == NULL) {
        _pygi_arg_cache_free ( (PyGIArgCache *)hc);
        return NULL;
    }

    g_base_info_unref( (GIBaseInfo *)key_type_info);
    g_base_info_unref( (GIBaseInfo *)value_type_info);

    return hc;
}

static PyGICallbackCache *
_callback_cache_new (GIArgInfo *arg_info,
                     GIInterfaceInfo *iface_info,
                     gssize child_offset)
{
   PyGICallbackCache *cc;

   cc = g_slice_new0 (PyGICallbackCache);
   ( (PyGIArgCache *)cc)->destroy_notify = (GDestroyNotify)_callback_cache_free_func;

   cc->user_data_index = g_arg_info_get_closure (arg_info);
   if (cc->user_data_index != -1)
       cc->user_data_index += child_offset;
   cc->destroy_notify_index = g_arg_info_get_destroy (arg_info);
   if (cc->destroy_notify_index != -1)
       cc->destroy_notify_index += child_offset;
   cc->scope = g_arg_info_get_scope (arg_info);
   g_base_info_ref( (GIBaseInfo *)iface_info);
   cc->interface_info = iface_info;
   return cc;
}

static PyGIArgCache *
_arg_cache_alloc (void)
{
    return g_slice_new0 (PyGIArgCache);
}

static void
_arg_cache_from_py_basic_type_setup (PyGIArgCache *arg_cache)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_basic_type_cache_adapter;
}

static void
_arg_cache_to_py_basic_type_setup (PyGIArgCache *arg_cache)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_basic_type_cache_adapter;
}

static void
_arg_cache_from_py_void_setup (PyGIArgCache *arg_cache)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_void;
}

static void
_arg_cache_to_py_void_setup (PyGIArgCache *arg_cache)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_void;
}

static void
_arg_cache_from_py_utf8_setup (PyGIArgCache *arg_cache,
                               GITransfer transfer)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_basic_type_cache_adapter;
    arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_utf8;
}

static void
_arg_cache_to_py_utf8_setup (PyGIArgCache *arg_cache,
                               GITransfer transfer)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_basic_type_cache_adapter;
    arg_cache->to_py_cleanup = _pygi_marshal_cleanup_to_py_utf8;
}

static gboolean
_arg_cache_from_py_array_setup (PyGIArgCache *arg_cache,
                                PyGICallableCache *callable_cache,
                                GITypeInfo *type_info,
                                GITransfer transfer,
                                PyGIDirection direction,
                                gssize arg_index)
{
    PyGISequenceCache *seq_cache = (PyGISequenceCache *)arg_cache;
    seq_cache->array_type = g_type_info_get_array_type (type_info);

    arg_cache->from_py_marshaller = _pygi_marshal_from_py_array;

    if (seq_cache->len_arg_index >= 0) {
        PyGIArgCache *child_cache = 
            _pygi_callable_cache_get_arg (callable_cache, seq_cache->len_arg_index);

        if (child_cache == NULL) {
            child_cache = _arg_cache_alloc ();
        } else if (child_cache->meta_type == PYGI_META_ARG_TYPE_CHILD ||
                   child_cache->meta_type == PYGI_META_ARG_TYPE_CHILD_NEEDS_UPDATE) {
            arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_array;
            return TRUE;
        }

        if (seq_cache->len_arg_index < arg_index)
            child_cache->meta_type = PYGI_META_ARG_TYPE_CHILD_NEEDS_UPDATE;
        else
            child_cache->meta_type = PYGI_META_ARG_TYPE_CHILD;

        child_cache->direction = direction;
        child_cache->to_py_marshaller = NULL;
        child_cache->from_py_marshaller = NULL;

        _pygi_callable_cache_set_arg (callable_cache, seq_cache->len_arg_index, child_cache);
    }

    arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_array;

    return TRUE;
}

static gboolean
_arg_cache_to_py_array_setup (PyGIArgCache *arg_cache,
                              PyGICallableCache *callable_cache,
                              GITypeInfo *type_info,
                              GITransfer transfer,
                              PyGIDirection direction,
                              gssize arg_index)
{
    PyGISequenceCache *seq_cache = (PyGISequenceCache *)arg_cache;
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_array;
    arg_cache->to_py_cleanup = _pygi_marshal_cleanup_to_py_array;

    seq_cache->array_type = g_type_info_get_array_type (type_info);

    if (seq_cache->len_arg_index >= 0) {
        PyGIArgCache *child_cache = _pygi_callable_cache_get_arg (callable_cache,
                                                                  seq_cache->len_arg_index);
        if (seq_cache->len_arg_index < arg_index)
             callable_cache->n_to_py_child_args++;

        if (child_cache != NULL) {
            callable_cache->to_py_args =
                g_slist_remove (callable_cache->to_py_args, child_cache);

            if (child_cache->meta_type == PYGI_META_ARG_TYPE_CHILD ||
                child_cache->meta_type == PYGI_META_ARG_TYPE_CHILD_NEEDS_UPDATE)
                return TRUE;
        } else {
            child_cache = _arg_cache_alloc ();
        }

        child_cache->meta_type = PYGI_META_ARG_TYPE_CHILD;
        child_cache->direction = direction;
        child_cache->to_py_marshaller = NULL;
        child_cache->from_py_marshaller = NULL;

        _pygi_callable_cache_set_arg (callable_cache, seq_cache->len_arg_index, child_cache);
    }

    return TRUE;
}

static void
_arg_cache_from_py_glist_setup (PyGIArgCache *arg_cache,
                                GITransfer transfer)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_glist;
    arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_glist;
}

static void
_arg_cache_to_py_glist_setup (PyGIArgCache *arg_cache,
                              GITransfer transfer)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_glist;
    arg_cache->to_py_cleanup = _pygi_marshal_cleanup_to_py_glist;
}

static void
_arg_cache_from_py_gslist_setup (PyGIArgCache *arg_cache,
                                 GITransfer transfer)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_gslist;
    arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_glist;
}

static void
_arg_cache_to_py_gslist_setup (PyGIArgCache *arg_cache,
                                 GITransfer transfer)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_gslist;
    arg_cache->to_py_cleanup = _pygi_marshal_cleanup_to_py_glist;
}

static void
_arg_cache_from_py_ghash_setup (PyGIArgCache *arg_cache)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_ghash;
    arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_ghash;
}

static void
_arg_cache_to_py_ghash_setup (PyGIArgCache *arg_cache)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_ghash;
    arg_cache->to_py_cleanup = _pygi_marshal_cleanup_to_py_ghash;
}

static void
_arg_cache_from_py_gerror_setup (PyGIArgCache *arg_cache)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_gerror;
    arg_cache->meta_type = PYGI_META_ARG_TYPE_CHILD;
}

static void
_arg_cache_to_py_gerror_setup (PyGIArgCache *arg_cache)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_gerror;
    arg_cache->meta_type = PYGI_META_ARG_TYPE_CHILD;
}

static void
_arg_cache_from_py_interface_union_setup (PyGIArgCache *arg_cache,
                                          GITransfer transfer)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_interface_struct_cache_adapter;
}

static void
_arg_cache_to_py_interface_union_setup (PyGIArgCache *arg_cache,
                                        GITransfer transfer)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_interface_struct_cache_adapter;
}

static void
_arg_cache_from_py_interface_struct_setup (PyGIArgCache *arg_cache,
                                           GIInterfaceInfo *iface_info,
                                           GITransfer transfer)
{
    PyGIInterfaceCache *iface_cache = (PyGIInterfaceCache *)arg_cache;
    iface_cache->is_foreign = g_struct_info_is_foreign ( (GIStructInfo*)iface_info);
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_interface_struct_cache_adapter;

    if (iface_cache->g_type == G_TYPE_VALUE)
        arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_interface_struct_gvalue;
    else if (iface_cache->is_foreign)
        arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_interface_struct_foreign;
}

static void
_arg_cache_to_py_interface_struct_setup (PyGIArgCache *arg_cache,
                                         GIInterfaceInfo *iface_info,
                                         GITransfer transfer)
{
    PyGIInterfaceCache *iface_cache = (PyGIInterfaceCache *)arg_cache;
    iface_cache->is_foreign = g_struct_info_is_foreign ( (GIStructInfo*)iface_info);
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_interface_struct_cache_adapter;

    if (iface_cache->is_foreign)
        arg_cache->to_py_cleanup = _pygi_marshal_cleanup_to_py_interface_struct_foreign;
}

static void
_arg_cache_from_py_interface_object_setup (PyGIArgCache *arg_cache,
                                           GITransfer transfer)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_interface_object;
    arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_interface_object;
}

static void
_arg_cache_to_py_interface_object_setup (PyGIArgCache *arg_cache,
                                         GITransfer transfer)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_interface_object_cache_adapter;
    arg_cache->to_py_cleanup = _pygi_marshal_cleanup_to_py_interface_object;
}

static void
_arg_cache_from_py_interface_callback_setup (PyGIArgCache *arg_cache,
                                             PyGICallableCache *callable_cache)
{
    PyGICallbackCache *callback_cache = (PyGICallbackCache *)arg_cache;
    if (callback_cache->user_data_index >= 0) {
        PyGIArgCache *user_data_arg_cache = _arg_cache_alloc ();
        user_data_arg_cache->meta_type = PYGI_META_ARG_TYPE_CHILD_WITH_PYARG;
        user_data_arg_cache->direction = PYGI_DIRECTION_FROM_PYTHON;
        _pygi_callable_cache_set_arg (callable_cache, callback_cache->user_data_index,
                                      user_data_arg_cache);
    }

    if (callback_cache->destroy_notify_index >= 0) {
        PyGIArgCache *destroy_arg_cache = _arg_cache_alloc ();
        destroy_arg_cache->meta_type = PYGI_META_ARG_TYPE_CHILD;
        destroy_arg_cache->direction = PYGI_DIRECTION_FROM_PYTHON;
        _pygi_callable_cache_set_arg (callable_cache, callback_cache->destroy_notify_index,
                                      destroy_arg_cache);
    }
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_interface_callback;
    arg_cache->from_py_cleanup = _pygi_marshal_cleanup_from_py_interface_callback;
}

static void
_arg_cache_to_py_interface_callback_setup (void)
{
    PyErr_Format(PyExc_NotImplementedError,
                 "Callback returns are not supported");
}

static void
_arg_cache_from_py_interface_enum_setup (PyGIArgCache *arg_cache,
                                         GITransfer transfer)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_interface_enum;
}

static void
_arg_cache_to_py_interface_enum_setup (PyGIArgCache *arg_cache,
                                       GITransfer transfer)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_interface_enum;
}

static void
_arg_cache_from_py_interface_flags_setup (PyGIArgCache *arg_cache,
                                          GITransfer transfer)
{
    arg_cache->from_py_marshaller = _pygi_marshal_from_py_interface_flags;
}

static void
_arg_cache_to_py_interface_flags_setup (PyGIArgCache *arg_cache,
                                        GITransfer transfer)
{
    arg_cache->to_py_marshaller = _pygi_marshal_to_py_interface_flags;
}

PyGIArgCache *
_arg_cache_new_for_interface (GIInterfaceInfo *iface_info,
                              PyGICallableCache *callable_cache,
                              GIArgInfo *arg_info,
                              GITransfer transfer,
                              PyGIDirection direction,
                              gssize c_arg_index,
                              gssize py_arg_index)
{
    PyGIInterfaceCache *iface_cache = NULL;
    PyGIArgCache *arg_cache = NULL;
    gssize child_offset = 0;
    GIInfoType info_type;

    if (callable_cache != NULL)
        child_offset =
            (callable_cache->function_type == PYGI_FUNCTION_TYPE_METHOD ||
                 callable_cache->function_type == PYGI_FUNCTION_TYPE_VFUNC) ? 1: 0;

    info_type = g_base_info_get_type ( (GIBaseInfo *)iface_info);

    /* Callbacks are special cased */
    if (info_type != GI_INFO_TYPE_CALLBACK) {
        iface_cache = _interface_cache_new (iface_info);

        arg_cache = (PyGIArgCache *)iface_cache;
        if (arg_cache == NULL)
            return NULL;
    }

    switch (info_type) {
        case GI_INFO_TYPE_UNION:
            if (direction & PYGI_DIRECTION_FROM_PYTHON)
               _arg_cache_from_py_interface_union_setup (arg_cache, transfer);

            if (direction & PYGI_DIRECTION_TO_PYTHON)
               _arg_cache_to_py_interface_union_setup (arg_cache, transfer);

            break;
        case GI_INFO_TYPE_BOXED:
        case GI_INFO_TYPE_STRUCT:
            if (direction & PYGI_DIRECTION_FROM_PYTHON)
               _arg_cache_from_py_interface_struct_setup (arg_cache,
                                                          iface_info,
                                                          transfer);

            if (direction & PYGI_DIRECTION_TO_PYTHON)
               _arg_cache_to_py_interface_struct_setup (arg_cache,
                                                        iface_info,
                                                        transfer);
            break;
        case GI_INFO_TYPE_OBJECT:
        case GI_INFO_TYPE_INTERFACE:
            if (direction & PYGI_DIRECTION_FROM_PYTHON)
               _arg_cache_from_py_interface_object_setup (arg_cache, transfer);

            if (direction & PYGI_DIRECTION_TO_PYTHON)
               _arg_cache_to_py_interface_object_setup (arg_cache, transfer);

            break;
        case GI_INFO_TYPE_CALLBACK:
            {
                PyGICallbackCache *callback_cache;

                if (direction & PYGI_DIRECTION_TO_PYTHON) {
                    _arg_cache_to_py_interface_callback_setup ();
                    return NULL;
                }

                callback_cache =
                    _callback_cache_new (arg_info,
                                         iface_info,
                                         child_offset);

                arg_cache = (PyGIArgCache *)callback_cache;
                if (arg_cache == NULL)
                    return NULL;

                if (direction & PYGI_DIRECTION_FROM_PYTHON)
                    _arg_cache_from_py_interface_callback_setup (arg_cache, callable_cache);

                break;
            }
        case GI_INFO_TYPE_ENUM:
            if (direction & PYGI_DIRECTION_FROM_PYTHON)
               _arg_cache_from_py_interface_enum_setup (arg_cache, transfer);

            if (direction & PYGI_DIRECTION_TO_PYTHON)
               _arg_cache_to_py_interface_enum_setup (arg_cache, transfer);

            break;
        case GI_INFO_TYPE_FLAGS:
            if (direction & PYGI_DIRECTION_FROM_PYTHON)
               _arg_cache_from_py_interface_flags_setup (arg_cache, transfer);

            if (direction & PYGI_DIRECTION_TO_PYTHON)
               _arg_cache_to_py_interface_flags_setup (arg_cache, transfer);

            break;
        default:
            g_assert_not_reached ();
    }

    if (arg_cache != NULL) {
        arg_cache->direction = direction;
        arg_cache->transfer = transfer;
        arg_cache->type_tag = GI_TYPE_TAG_INTERFACE;
        arg_cache->py_arg_index = py_arg_index;
        arg_cache->c_arg_index = c_arg_index;

        if (iface_cache != NULL) {
            g_base_info_ref ( (GIBaseInfo *)iface_info);
            iface_cache->interface_info = iface_info;
        }
    }

    return arg_cache;
}

PyGIArgCache *
_arg_cache_new (GITypeInfo *type_info,
                PyGICallableCache *callable_cache,
                GIArgInfo *arg_info,
                GITransfer transfer,
                PyGIDirection direction,
                gssize c_arg_index,
                gssize py_arg_index)
{
    PyGIArgCache *arg_cache = NULL;
    gssize child_offset = 0;
    GITypeTag type_tag;

    type_tag = g_type_info_get_tag (type_info);

    if (callable_cache != NULL)
        child_offset =
            (callable_cache->function_type == PYGI_FUNCTION_TYPE_METHOD ||
                callable_cache->function_type == PYGI_FUNCTION_TYPE_VFUNC) ? 1: 0;

    switch (type_tag) {
       case GI_TYPE_TAG_VOID:
           arg_cache = _arg_cache_alloc ();
           if (arg_cache == NULL)
               break;

           if (direction & PYGI_DIRECTION_FROM_PYTHON)
               _arg_cache_from_py_void_setup (arg_cache);

           if (direction & PYGI_DIRECTION_TO_PYTHON)
               _arg_cache_to_py_void_setup (arg_cache);

           break;
       case GI_TYPE_TAG_BOOLEAN:
       case GI_TYPE_TAG_INT8:
       case GI_TYPE_TAG_UINT8:
       case GI_TYPE_TAG_INT16:
       case GI_TYPE_TAG_UINT16:
       case GI_TYPE_TAG_INT32:
       case GI_TYPE_TAG_UINT32:
       case GI_TYPE_TAG_INT64:
       case GI_TYPE_TAG_UINT64:
       case GI_TYPE_TAG_FLOAT:
       case GI_TYPE_TAG_DOUBLE:
       case GI_TYPE_TAG_UNICHAR:
       case GI_TYPE_TAG_GTYPE:
           arg_cache = _arg_cache_alloc ();
           if (arg_cache == NULL)
               break;

           if (direction