/* GObject - GLib Type, Object, Parameter and Signal Library
* Copyright (C) 1997, 1998, 1999, 2000 Tim Janik and Red Hat, Inc.
*
* 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 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., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* FIXME: MT-safety
*/
#include <string.h>
#include "gvalue.h"
#include "gvaluecollector.h"
/* --- typedefs & structures --- */
typedef struct
{
GType value_type1;
GType value_type2;
GValueExchange func;
GType first_type;
} ExchangeEntry;
/* --- variables --- */
static GHashTable *param_exchange_ht = NULL;
/* --- functions --- */
void
g_value_init (GValue *value,
GType g_type)
{
GTypeValueTable *value_table = g_type_value_table_peek (g_type);
g_return_if_fail (value != NULL);
g_return_if_fail (G_VALUE_TYPE (value) == 0);
if (value_table)
{
memset (value, 0, sizeof (*value));
value->g_type = g_type;
value_table->value_init (value);
}
else
g_warning (G_STRLOC ": cannot initialize value of type `%s' which has no GTypeValueTable",
g_type_name (g_type));
}
void
g_value_copy (const GValue *src_value,
GValue *dest_value)
{
GTypeValueTable *value_table;
g_return_if_fail (G_IS_VALUE (src_value));
g_return_if_fail (G_IS_VALUE (dest_value));
g_return_if_fail (g_type_is_a (G_VALUE_TYPE (src_value), G_VALUE_TYPE (dest_value)));
value_table = g_type_value_table_peek (G_VALUE_TYPE (dest_value));
if (!value_table)
g_return_if_fail (g_type_value_table_peek (G_VALUE_TYPE (dest_value)) != NULL);
if (src_value != dest_value)
{
/* make sure dest_value's value is free()d and zero initialized */
g_value_reset (dest_value);
value_table->value_copy (src_value, dest_value);
}
}
gboolean
g_value_fits_pointer (const GValue *value)
{
GTypeValueTable *value_table;
g_return_val_if_fail (G_IS_VALUE (value), FALSE);
value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
if (!value_table)
g_return_val_if_fail (g_type_value_table_peek (G_VALUE_TYPE (value)) != NULL, FALSE);
return value_table->value_peek_pointer != NULL;
}
gpointer
g_value_get_as_pointer (const GValue *value)
{
GTypeValueTable *value_table;
g_return_val_if_fail (G_IS_VALUE (value), NULL);
value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
if (!value_table)
g_return_val_if_fail (g_type_value_table_peek (G_VALUE_TYPE (value)) != NULL, NULL);
if (!value_table->value_peek_pointer)
g_return_val_if_fail (g_value_fits_pointer (value) == TRUE, NULL);
return value_table->value_peek_pointer (value);
}
void
g_value_set_instance (GValue *value,
gpointer instance)
{
g_return_if_fail (G_IS_VALUE (value));
g_value_reset (value);
if (instance)
{
GType g_type = G_VALUE_TYPE (value);
GTypeValueTable *value_table = g_type_value_table_peek (g_type);
GTypeCValue cvalue = { 0, };
gchar *error_msg;
g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance));
g_return_if_fail (g_type_is_a (G_TYPE_FROM_INSTANCE (instance), G_VALUE_TYPE (value)));
g_return_if_fail (strcmp (value_table->collect_format, "p") == 0);
cvalue.v_pointer = instance;
error_msg = value_table->collect_value (value, 1, &cvalue, 0);
if (error_msg)
{
g_warning ("%s: %s", G_STRLOC, error_msg);
g_free (error_msg);
/* we purposely leak the value here, it might not be
* in a sane state if an error condition occoured
*/
memset (value, 0, sizeof (*value));
value->g_type = g_type;
value_table->value_init (value);
}
}
}
void
g_value_unset (GValue *value)
{
GTypeValueTable *value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
g_return_if_fail (G_IS_VALUE (value));
if (!value_table)
g_return_if_fail (g_type_value_table_peek (G_VALUE_TYPE (value)) != NULL);
if (value_table->value_free)
value_table->value_free (value);
memset (value, 0, sizeof (*value));
}
void
g_value_reset (GValue *value)
{
GTypeValueTable *value_table;
GType g_type;
g_return_if_fail (G_IS_VALUE (value));
value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
g_type = G_VALUE_TYPE (value);
if (value_table->value_free)
value_table->value_free (value);
memset (value, 0, sizeof (*value));
value->g_type = g_type;
value_table->value_init (value);
}
static gboolean
exchange_entries_equal (gconstpointer v1,
gconstpointer v2)
{
const ExchangeEntry *entry1 = v1;
const ExchangeEntry *entry2 = v2;
return (entry1->value_type1 == entry2->value_type1 &&
entry1->value_type2 == entry2->value_type2);
}
static guint
exchange_entry_hash (gconstpointer key)
{
const ExchangeEntry *entry = key;
return entry->value_type1 ^ entry->value_type2;
}
static void
value_exchange_memcpy (GValue *value1,
GValue *value2)
{
GValue tmp_value;
memcpy (&tmp_value.data, &value1->data, sizeof (value1->data));
memcpy (&value1->data, &value2->data, sizeof (value1->data));
memcpy (&value2->data, &tmp_value.data, sizeof (value2->data));
}
static inline GValueExchange
exchange_func_lookup (GType value_type1,
GType value_type2,
gboolean *need_swap)
{
if (value_type1 == value_type2)
return value_exchange_memcpy;
else
{
GType type1 = value_type1;
do
{
GType type2 = value_type2;
do
{
ExchangeEntry entry, *ret;
entry.value_type1 = MIN (type1, type2);
entry.value_type2 = MAX (type1, type2);
ret = g_hash_table_lookup (param_exchange_ht, &entry);
if (ret)
{
if (need_swap)
*need_swap = ret->first_type == type2;
return ret->func;
}
type2 = g_type_parent (type2);
}
while (type2);
type1 = g_type_parent (type1);
}
while (type1);
}
return NULL;
}
void
g_value_register_exchange_func (GType value_type1,
GType value_type2,
GValueExchange func)
{
ExchangeEntry entry;
g_return_if_fail (g_type_name (value_type1) != NULL);
g_return_if_fail (g_type_name (value_type2) != NULL);
g_return_if_fail (func != NULL);
entry.value_type1 = MIN (value_type1, value_type2);
entry.value_type2 = MAX (value_type1, value_type2);
if (param_exchange_ht && g_hash_table_lookup (param_exchange_ht, &entry))
g_warning (G_STRLOC ": cannot re-register param value exchange function "
"for `%s' and `%s'",
g_type_name (value_type1),
g_type_name (value_type2));
else
{
ExchangeEntry *entry = g_new (ExchangeEntry, 1);
if (!param_exchange_ht)
param_exchange_ht = g_hash_table_new (exchange_entry_hash, exchange_entries_equal);
entry->value_type1 = MIN (value_type1, value_type2);
entry->value_type2 = MAX (value_type1, value_type2);
entry->func = func;
entry->first_type = value_type1;
g_hash_table_insert (param_exchange_ht, entry, entry);
}
}
gboolean
g_value_types_exchangable (GType value_type1,
GType value_type2)
{
g_return_val_if_fail (G_TYPE_IS_VALUE (value_type1), FALSE); /* these might bite us, think G_TYPE_ENUM */
g_return_val_if_fail (G_TYPE_IS_VALUE (value_type2), FALSE);
return exchange_func_lookup (value_type1, value_type2, NULL) != NULL;
}
gboolean
g_values_exchange (GValue *value1,
GValue *value2)
{
g_return_val_if_fail (G_IS_VALUE (value1), FALSE);
g_return_val_if_fail (G_IS_VALUE (value2), FALSE);
if (value1 != value2)
{
gboolean need_swap;
GValueExchange value_exchange = exchange_func_lookup (G_VALUE_TYPE (value1),
G_VALUE_TYPE (value2),
&need_swap);
if (value_exchange)
{
if (need_swap)
value_exchange (value2, value1);
else
value_exchange (value1, value2);
}
return value_exchange != NULL;
}
return TRUE;
}
gboolean
g_value_convert (const GValue *src_value,
GValue *dest_value)
{
gboolean success = TRUE;
g_return_val_if_fail (G_IS_VALUE (src_value), FALSE);
g_return_val_if_fail (G_IS_VALUE (dest_value), FALSE);
if (src_value != dest_value)
{
GValue tmp_value = { 0, };
g_value_init (&tmp_value, G_VALUE_TYPE (src_value));
g_value_copy (src_value, &tmp_value);
success = g_values_exchange (&tmp_value, dest_value);
g_value_unset (&tmp_value);
}
return success;
}