mutter/clutter/json/json-object.c
2009-03-17 14:13:31 +00:00

304 lines
7.8 KiB
C

/* json-object.c - JSON object implementation
*
* This file is part of JSON-GLib
* Copyright (C) 2007 OpenedHand Ltd.
*
* 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.
*
* Author:
* Emmanuele Bassi <ebassi@openedhand.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib.h>
#include "json-types.h"
/**
* SECTION:json-object
* @short_description: a JSON object representation
*
* #JsonArray is the representation of the object type inside JSON. It contains
* #JsonNode<!-- -->s, which may contain fundamental types, arrays or other
* objects. Each member of an object is accessed using its name.
*
* Since objects can be expensive, they are reference counted. You can control
* the lifetime of a #JsonObject using json_object_ref() and json_object_unref().
*
* To add a member with a given name, use json_object_add_member().
* To extract a member with a given name, use json_object_get_member().
* To retrieve the list of members, use json_object_get_members().
* To retrieve the size of the object (that is, the number of members it has), use
* json_object_get_size().
*/
struct _JsonObject
{
GHashTable *members;
volatile gint ref_count;
};
GType
json_object_get_type (void)
{
static GType object_type = 0;
if (G_UNLIKELY (!object_type))
object_type = g_boxed_type_register_static ("JsonObject",
(GBoxedCopyFunc) json_object_ref,
(GBoxedFreeFunc) json_object_unref);
return object_type;
}
/**
* json_object_new:
*
* Creates a new #JsonObject, an JSON object type representation.
*
* Return value: the newly created #JsonObject
*/
JsonObject *
json_object_new (void)
{
JsonObject *object;
object = g_slice_new (JsonObject);
object->ref_count = 1;
object->members = g_hash_table_new_full (g_str_hash, g_str_equal,
g_free,
(GDestroyNotify) json_node_free);
return object;
}
/**
* json_object_ref:
* @object: a #JsonObject
*
* Increase by one the reference count of a #JsonObject.
*
* Return value: the passed #JsonObject, with the reference count
* increased by one.
*/
JsonObject *
json_object_ref (JsonObject *object)
{
g_return_val_if_fail (object != NULL, NULL);
g_return_val_if_fail (object->ref_count > 0, NULL);
g_atomic_int_exchange_and_add (&object->ref_count, 1);
return object;
}
/**
* json_object_unref:
* @object: a #JsonObject
*
* Decreases by one the reference count of a #JsonObject. If the
* reference count reaches zero, the object is destroyed and all
* its allocated resources are freed.
*/
void
json_object_unref (JsonObject *object)
{
gint old_ref;
g_return_if_fail (object != NULL);
g_return_if_fail (object->ref_count > 0);
old_ref = g_atomic_int_get (&object->ref_count);
if (old_ref > 1)
g_atomic_int_compare_and_exchange (&object->ref_count, old_ref, old_ref - 1);
else
{
g_hash_table_destroy (object->members);
object->members = NULL;
g_slice_free (JsonObject, object);
}
}
/**
* json_object_add_member:
* @object: a #JsonObject
* @member_name: the name of the member
* @node: the value of the member
*
* Adds a member named @member_name and containing @node into a #JsonObject.
* The object will take ownership of the #JsonNode.
*/
void
json_object_add_member (JsonObject *object,
const gchar *member_name,
JsonNode *node)
{
gchar *name;
g_return_if_fail (object != NULL);
g_return_if_fail (member_name != NULL);
g_return_if_fail (node != NULL);
if (json_object_has_member (object, member_name))
{
g_warning ("JsonObject already has a '%s' member of type '%s'",
member_name,
json_node_type_name (node));
return;
}
name = g_strdelimit (g_strdup (member_name), G_STR_DELIMITERS, '_');
g_hash_table_replace (object->members, name, node);
}
/* FIXME: yuck. we really need to depend on GLib 2.14 */
#if GLIB_MAJOR_VERSION == 2 && GLIB_MINOR_VERSION < 14
static void
get_keys (gpointer key,
gpointer value,
gpointer user_data)
{
GList **keys = user_data;
*keys = g_list_prepend (*keys, key);
}
static GList *
g_hash_table_get_keys (GHashTable *hash_table)
{
GList *retval = NULL;
g_return_val_if_fail (hash_table != NULL, NULL);
g_hash_table_foreach (hash_table, get_keys, &retval);
return retval;
}
#endif /* GLIB_MAJOR_VERSION == 2 && GLIB_MINOR_VERSION < 14 */
/**
* json_object_get_members:
* @object: a #JsonObject
*
* Retrieves all the names of the members of a #JsonObject. You can
* obtain the value for each member using json_object_get_member().
*
* Return value: (transfer container) (element-type utf8): a #GList of
* member names. The content of the list is owned by the #JsonObject
* and should never be modified or freed. When you have finished using
* the returned list, use g_list_free() to free the resources it has
* allocated.
*/
GList *
json_object_get_members (JsonObject *object)
{
g_return_val_if_fail (object != NULL, NULL);
return g_hash_table_get_keys (object->members);
}
/**
* json_object_get_member:
* @object: a #JsonObject
* @member_name: the name of the JSON object member to access
*
* Retrieves the #JsonNode containing the value of @member_name inside
* a #JsonObject.
*
* Return value: (transfer none): a pointer to the node for the requested object
* member, or %NULL
*/
JsonNode *
json_object_get_member (JsonObject *object,
const gchar *member_name)
{
gchar *name;
JsonNode *retval;
g_return_val_if_fail (object != NULL, NULL);
g_return_val_if_fail (member_name != NULL, NULL);
name = g_strdelimit (g_strdup (member_name), G_STR_DELIMITERS, '_');
retval = g_hash_table_lookup (object->members, name);
g_free (name);
return retval;
}
/**
* json_object_has_member:
* @object: a #JsonObject
* @member_name: the name of a JSON object member
*
* Checks whether @object has a member named @member_name.
*
* Return value: %TRUE if the JSON object has the requested member
*/
gboolean
json_object_has_member (JsonObject *object,
const gchar *member_name)
{
gchar *name;
gboolean retval;
g_return_val_if_fail (object != NULL, FALSE);
g_return_val_if_fail (member_name != NULL, FALSE);
name = g_strdelimit (g_strdup (member_name), G_STR_DELIMITERS, '_');
retval = (g_hash_table_lookup (object->members, name) != NULL);
g_free (name);
return retval;
}
/**
* json_object_get_size:
* @object: a #JsonObject
*
* Retrieves the number of members of a #JsonObject.
*
* Return value: the number of members
*/
guint
json_object_get_size (JsonObject *object)
{
g_return_val_if_fail (object != NULL, 0);
return g_hash_table_size (object->members);
}
/**
* json_object_remove_member:
* @object: a #JsonObject
* @member_name: the name of the member to remove
*
* Removes @member_name from @object, freeing its allocated resources.
*/
void
json_object_remove_member (JsonObject *object,
const gchar *member_name)
{
gchar *name;
g_return_if_fail (object != NULL);
g_return_if_fail (member_name != NULL);
name = g_strdelimit (g_strdup (member_name), G_STR_DELIMITERS, '_');
g_hash_table_remove (object->members, name);
g_free (name);
}