/* json-node.c - JSON object model node
*
* This file is part of JSON-GLib
* Copyright (C) 2007 OpenedHand Ltd.
* Copyright (C) 2009 Intel Corp.
* Copyright (C) 2015 Collabora 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 2.1 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, see <http://www.gnu.org/licenses/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
* Philip Withnall <philip.withnall@collabora.co.uk>
*/
#include "config.h"
#include <glib.h>
#include "json-types.h"
#include "json-types-private.h"
#include "json-debug.h"
/**
* SECTION:json-node
* @short_description: Node in a JSON object model
*
* A #JsonNode is a generic container of elements inside a JSON stream.
* It can contain fundamental types (integers, booleans, floating point
* numbers, strings) and complex types (arrays and objects).
*
* When parsing a JSON data stream you extract the root node and walk
* the node tree by retrieving the type of data contained inside the
* node with the %JSON_NODE_TYPE macro. If the node contains a fundamental
* type you can retrieve a copy of the #GValue holding it with the
* json_node_get_value() function, and then use the #GValue API to extract
* the data; if the node contains a complex type you can retrieve the
* #JsonObject or the #JsonArray using json_node_get_object() or
* json_node_get_array() respectively, and then retrieve the nodes
* they contain.
*
* A #JsonNode may be marked as immutable using json_node_seal(). This marks the
* node and all its descendents as read-only, and means that subsequent calls to
* setter functions (such as json_node_set_array()) on them will abort as a
* programmer error. By marking a node tree as immutable, it may be referenced
* in multiple places and its hash value cached for fast lookups, without the
* possibility of a value deep within the tree changing and affecting hash
* values. Immutable #JsonNodes may be passed to functions which retain a
* reference to them without needing to take a copy.
*
* #JsonNode supports two types of memory management: alloc/free semantics, and
* ref/unref semantics. The two may be mixed to a limited extent: nodes may be
* allocated (which gives them a reference count of 1), referenced zero or more
* times, unreferenced exactly that number of times (using json_node_unref()),
* then either unreferenced exactly once more or freed (using json_node_free())
* to destroy them. json_node_free() must not be used when a node might have a
* reference count not equal to 1. To this end, json-glib uses json_node_copy()
* and json_node_unref() internally.
*/
G_DEFINE_BOXED_TYPE (JsonNode, json_node, json_node_copy, json_node_unref);
/**
* json_node_get_value_type:
* @node: a #JsonNode
*
* Returns the #GType of the payload of the node.
*
* Return value: a #GType for the payload.
*
* Since: 0.4
*/
GType
json_node_get_value_type (JsonNode *node)
{
g_return_val_if_fail (node != NULL, G_TYPE_INVALID);
switch (node->type)
{
case JSON_NODE_OBJECT:
return JSON_TYPE_OBJECT;
case JSON_NODE_ARRAY:
return JSON_TYPE_ARRAY;
case JSON_NODE_NULL:
return G_TYPE_INVALID;
case JSON_NODE_VALUE:
if (node->data.value)
return JSON_VALUE_TYPE (node->data.value);
else
return G_TYPE_INVALID;
default:
g_assert_not_reached ();
return G_TYPE_INVALID;
}
}
/**
* json_node_alloc: (constructor)
*
* Allocates a new #JsonNode. Use json_node_init() and its variants
* to initialize the returned value.
*
* Return value: (transfer full): the newly allocated #JsonNode. Use
* json_node_free() to free the resources allocated by this function
*
* Since: 0.16
*/
JsonNode *
json_node_alloc (void)
{
JsonNode *node = NULL;
node = g_slice_new0 (JsonNode);
node->ref_count = 1;
node->allocated = TRUE;
return node;
}
static void
json_node_unset (JsonNode *node)
{
/* Note: Don't use JSON_NODE_IS_VALID here because this may legitimately be
* called with (node->ref_count == 0) from json_node_unref(). */
g_assert (node != NULL);
switch (node->type)
{
case JSON_NODE_OBJECT:
if (node->data.object)
json_object_unref (node->data.object);
break;
case JSON_NODE_ARRAY:
if (node->data.array)
json_array_unref (node->data.array);
break;
case JSON_NODE_VALUE:
if (node->data.value)
json_value_unref (node->data.value);
break;
case JSON_NODE_NULL:
break;
}
}
/**
* json_node_init:
* @node: the #JsonNode to initialize
* @type: the type of JSON node to initialize @node to
*
* Initializes a @node to a specific @type.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init (JsonNode *node,
JsonNodeType type)
{
g_return_val_if_fail (type >= JSON_NODE_OBJECT &&
type <= JSON_NODE_NULL, NULL);
g_return_val_if_fail (node->ref_count == 1, NULL);
json_node_unset (node);
node->type = type;
return node;
}
/**
* json_node_init_object:
* @node: the #JsonNode to initialize
* @object: (allow-none): the #JsonObject to initialize @node with, or %NULL
*
* Initializes @node to %JSON_NODE_OBJECT and sets @object into it.
*
* This function will take a reference on @object.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init_object (JsonNode *node,
JsonObject *object)
{
g_return_val_if_fail (node != NULL, NULL);
json_node_init (node, JSON_NODE_OBJECT);
json_node_set_object (node, object);
return node;
}
/**
* json_node_init_array:
* @node: the #JsonNode to initialize
* @array: (allow-none): the #JsonArray to initialize @node with, or %NULL
*
* Initializes @node to %JSON_NODE_ARRAY and sets @array into it.
*
* This function will take a reference on @array.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init_array (JsonNode *node,
JsonArray *array)
{
g_return_val_if_fail (node != NULL, NULL);
json_node_init (node, JSON_NODE_ARRAY);
json_node_set_array (node, array);
return node;
}
/**
* json_node_init_int:
* @node: the #JsonNode to initialize
* @value: an integer
*
* Initializes @node to %JSON_NODE_VALUE and sets @value into it.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init_int (JsonNode *node,
gint64 value)
{
g_return_val_if_fail (node != NULL, NULL);
json_node_init (node, JSON_NODE_VALUE);
json_node_set_int (node, value);
return node;
}
/**
* json_node_init_double:
* @node: the #JsonNode to initialize
* @value: a floating point value
*
* Initializes @node to %JSON_NODE_VALUE and sets @value into it.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init_double (JsonNode *node,
gdouble value)
{
g_return_val_if_fail (node != NULL, NULL);
json_node_init (node, JSON_NODE_VALUE);
json_node_set_double (node, value);
return node;
}
/**
* json_node_init_boolean:
* @node: the #JsonNode to initialize
* @value: a boolean value
*
* Initializes @node to %JSON_NODE_VALUE and sets @value into it.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init_boolean (JsonNode *node,
gboolean value)
{
g_return_val_if_fail (node != NULL, NULL);
json_node_init (node, JSON_NODE_VALUE);
json_node_set_boolean (node, value);
return node;
}
/**
* json_node_init_string:
* @node: the #JsonNode to initialize
* @value: (allow-none): a string value
*
* Initializes @node to %JSON_NODE_VALUE and sets @value into it.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init_string (JsonNode *node,
const char *value)
{
g_return_val_if_fail (node != NULL, NULL);
json_node_init (node, JSON_NODE_VALUE);
json_node_set_string (node, value);
return node;
}
/**
* json_node_init_null:
* @node: the #JsonNode to initialize
*
* Initializes @node to %JSON_NODE_NULL.
*
* If the node has already been initialized once, it will be reset to
* the given type, and any data contained will be cleared.
*
* Return value: (transfer none): the initialized #JsonNode
*
* Since: 0.16
*/
JsonNode *
json_node_init_null (JsonNode *node)
{
g_return_val_if_fail (node != NULL, NULL);
return json_node_init (node, JSON_NODE_NULL);
}
/**
* json_node_new: (constructor)
* @type: a #JsonNodeType
*
* Creates a new #JsonNode of @type.
*
* This is a convenience function for json_node_alloc() and json_node_init(),
* and it's the equivalent of:
*
* |[<!-- language="C" -->
json_node_init (json_node_alloc (), type);
* ]|
*
* Return value: (transfer full): the newly created #JsonNode
*/
JsonNode *
json_node_new (JsonNodeType type)
{
g_return_val_if_fail (type >= JSON_NODE_OBJECT &&
type <= JSON_NODE_NULL, NULL);
return json_node_init (json_node_alloc (), type);
}
/**
* json_node_copy:
* @node: a #JsonNode
*
* Copies @node. If the node contains complex data types, their reference
* counts are increased, regardless of whether the node is mutable or
* immutable.
*
* The copy will be immutable if, and only if, @node is immutable. However,
* there should be no need to copy an immutable node.
*
* Return value: (transfer full): the copied #JsonNode
*/
JsonNode *
json_node_copy (JsonNode *node)
{
JsonNode *copy;
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
copy = json_node_alloc ();
copy->type = node->type;
copy->immutable = node->immutable;
#ifdef JSON_ENABLE_DEBUG
if (node->immutable)
{
JSON_NOTE (NODE, "Copying immutable JsonNode %p of type %s",
node,
json_node_type_name (node));
}
#endif
switch (copy->type)
{
case JSON_NODE_OBJECT:
copy->data.object = json_node_dup_object (node);
break;
case JSON_NODE_ARRAY:
copy->data.array = json_node_dup_array (node);
break;
case JSON_NODE_VALUE:
if (node->data.value)
copy->data.value = json_value_ref (node->data.value);
break;
case JSON_NODE_NULL:
break;
default:
g_assert_not_reached ();
}
return copy;
}
/**
* json_node_ref:
* @node: a #JsonNode
*
* Increment the reference count of @node.
*
* Since: 1.2
* Returns: (transfer full): a pointer to @node
*/
JsonNode *
json_node_ref (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
g_atomic_int_inc (&node->ref_count);
return node;
}
/**
* json_node_unref:
* @node: (transfer full): a #JsonNode
*
* Decrement the reference count of @node. If it reaches zero, the node is
* freed.
*
* Since: 1.2
*/
void
json_node_unref (JsonNode *node)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
if (g_atomic_int_dec_and_test (&node->ref_count))
{
json_node_unset (node);
if (node->allocated)
g_slice_free (JsonNode, node);
}
}
/**
* json_node_set_object:
* @node: a #JsonNode initialized to %JSON_NODE_OBJECT
* @object: (nullable): a #JsonObject
*
* Sets @objects inside @node. The reference count of @object is increased.
*
* If @object is %NULL, the node’s existing object is cleared.
*
* It is an error to call this on an immutable node, or on a node which is not
* an object node.
*/
void
json_node_set_object (JsonNode *node,
JsonObject *object)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_OBJECT);
g_return_if_fail (!node->immutable);
if (node->data.object != NULL)
json_object_unref (node->data.object);
if (object)
node->data.object = json_object_ref (object);
else
node->data.object = NULL;
}
/**
* json_node_take_object:
* @node: a #JsonNode initialized to %JSON_NODE_OBJECT
* @object: (transfer full): a #JsonObject
*
* Sets @object inside @node. The reference count of @object is not increased.
*
* It is an error to call this on an immutable node, or on a node which is not
* an object node.
*/
void
json_node_take_object (JsonNode *node,
JsonObject *object)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_OBJECT);
g_return_if_fail (!node->immutable);
if (node->data.object)
{
json_object_unref (node->data.object);
node->data.object = NULL;
}
if (object)
node->data.object = object;
}
/**
* json_node_get_object:
* @node: a #JsonNode
*
* Retrieves the #JsonObject stored inside a #JsonNode. It is a programmer error
* to call this on a node which doesn’t hold an object value. Use
* %JSON_NODE_HOLDS_OBJECT first.
*
* Return value: (transfer none) (nullable): the #JsonObject
*/
JsonObject *
json_node_get_object (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
g_return_val_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_OBJECT, NULL);
return node->data.object;
}
/**
* json_node_dup_object:
* @node: a #JsonNode
*
* Retrieves the #JsonObject inside @node. The reference count of
* the returned object is increased. It is a programmer error
* to call this on a node which doesn’t hold an object value. Use
* %JSON_NODE_HOLDS_OBJECT first.
*
* Return value: (transfer full) (nullable): the #JsonObject
*/
JsonObject *
json_node_dup_object (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
g_return_val_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_OBJECT, NULL);
if (node->data.object)
return json_object_ref (node->data.object);
return NULL;
}
/**
* json_node_set_array:
* @node: a #JsonNode initialized to %JSON_NODE_ARRAY
* @array: a #JsonArray
*
* Sets @array inside @node and increases the #JsonArray reference count.
*
* It is an error to call this on an immutable node, or on a node which is not
* an array node.
*/
void
json_node_set_array (JsonNode *node,
JsonArray *array)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_ARRAY);
g_return_if_fail (!node->immutable);
if (node->data.array)
json_array_unref (node->data.array);
if (array)
node->data.array = json_array_ref (array);
else
node->data.array = NULL;
}
/**
* json_node_take_array:
* @node: a #JsonNode initialized to %JSON_NODE_ARRAY
* @array: (transfer full): a #JsonArray
*
* Sets @array into @node without increasing the #JsonArray reference count.
*
* It is an error to call this on an immutable node, or a node which is not
* an array node.
*/
void
json_node_take_array (JsonNode *node,
JsonArray *array)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_ARRAY);
g_return_if_fail (!node->immutable);
if (node->data.array)
{
json_array_unref (node->data.array);
node->data.array = NULL;
}
if (array)
node->data.array = array;
}
/**
* json_node_get_array:
* @node: a #JsonNode
*
* Retrieves the #JsonArray stored inside a #JsonNode. It is a programmer error
* to call this on a node which doesn’t hold an array value. Use
* %JSON_NODE_HOLDS_ARRAY first.
*
* Return value: (transfer none) (nullable): the #JsonArray
*/
JsonArray *
json_node_get_array (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
g_return_val_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_ARRAY, NULL);
return node->data.array;
}
/**
* json_node_dup_array:
* @node: a #JsonNode
*
* Retrieves the #JsonArray stored inside a #JsonNode and returns it
* with its reference count increased by one. It is a programmer error
* to call this on a node which doesn’t hold an array value. Use
* %JSON_NODE_HOLDS_ARRAY first.
*
* Return value: (transfer full) (nullable): the #JsonArray with its reference
* count increased.
*/
JsonArray *
json_node_dup_array (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
g_return_val_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_ARRAY, NULL);
if (node->data.array)
return json_array_ref (node->data.array);
return NULL;
}
/**
* json_node_get_value:
* @node: a #JsonNode
* @value: (out caller-allocates): return location for an uninitialized value
*
* Retrieves a value from a #JsonNode and copies into @value. When done
* using it, call g_value_unset() on the #GValue. It is a programmer error
* to call this on a node which doesn’t hold a scalar value. Use
* %JSON_NODE_HOLDS_VALUE first.
*/
void
json_node_get_value (JsonNode *node,
GValue *value)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_VALUE);
if (node->data.value)
{
g_value_init (value, JSON_VALUE_TYPE (node->data.value));
switch (JSON_VALUE_TYPE (node->data.value))
{
case G_TYPE_INT64:
g_value_set_int64 (value, json_value_get_int (node->data.value));
break;
case G_TYPE_DOUBLE:
g_value_set_double (value, json_value_get_double (node->data.value));
break;
case G_TYPE_BOOLEAN:
g_value_set_boolean (value, json_value_get_boolean (node->data.value));
break;
case G_TYPE_STRING:
g_value_set_string (value, json_value_get_string (node->data.value));
break;
default:
break;
}
}
}
/**
* json_node_set_value:
* @node: a #JsonNode initialized to %JSON_NODE_VALUE
* @value: the #GValue to set
*
* Sets @value inside @node. The passed #GValue is copied into the #JsonNode.
*
* It is an error to call this on an immutable node, or on a node which is not
* a value node.
*/
void
json_node_set_value (JsonNode *node,
const GValue *value)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_VALUE);
g_return_if_fail (G_VALUE_TYPE (value) != G_TYPE_INVALID);
g_return_if_fail (!node->immutable);
if (node->data.value == NULL)
node->data.value = json_value_alloc ();
switch (G_VALUE_TYPE (value))
{
/* auto-promote machine integers to 64 bit integers */
case G_TYPE_INT64:
case G_TYPE_INT:
json_value_init (node->data.value, JSON_VALUE_INT);
if (G_VALUE_TYPE (value) == G_TYPE_INT64)
json_value_set_int (node->data.value, g_value_get_int64 (value));
else
json_value_set_int (node->data.value, g_value_get_int (value));
break;
case G_TYPE_BOOLEAN:
json_value_init (node->data.value, JSON_VALUE_BOOLEAN);
json_value_set_boolean (node->data.value, g_value_get_boolean (value));
break;
/* auto-promote single-precision floats to double precision floats */
case G_TYPE_DOUBLE:
case G_TYPE_FLOAT:
json_value_init (node->data.value, JSON_VALUE_DOUBLE);
if (G_VALUE_TYPE (value) == G_TYPE_DOUBLE)
json_value_set_double (node->data.value, g_value_get_double (value));
else
json_value_set_double (node->data.value, g_value_get_float (value));
break;
case G_TYPE_STRING:
json_value_init (node->data.value, JSON_VALUE_STRING);
json_value_set_string (node->data.value, g_value_get_string (value));
break;
default:
g_message ("Invalid value of type '%s'",
g_type_name (G_VALUE_TYPE (value)));
return;
}
}
/**
* json_node_free:
* @node: a #JsonNode
*
* Frees the resources allocated by @node.
*/
void
json_node_free (JsonNode *node)
{
g_return_if_fail (node == NULL || JSON_NODE_IS_VALID (node));
g_return_if_fail (node == NULL || node->allocated);
if (G_LIKELY (node))
{
if (node->ref_count > 1)
g_warning ("Freeing a JsonNode %p owned by other code.", node);
json_node_unset (node);
g_slice_free (JsonNode, node);
}
}
/**
* json_node_seal:
* @node: a #JsonNode
*
* Seals the #JsonNode, making it immutable to further changes. In order to be
* sealed, the @node must have a type and value set. The value will be
* recursively sealed — if the node holds an object, that #JsonObject will be
* sealed, etc.
*
* If the @node is already immutable, this is a no-op.
*
* Since: 1.2
*/
void
json_node_seal (JsonNode *node)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
if (node->immutable)
return;
switch (node->type)
{
case JSON_NODE_OBJECT:
g_return_if_fail (node->data.object != NULL);
json_object_seal (node->data.object);
break;
case JSON_NODE_ARRAY:
g_return_if_fail (node->data.array != NULL);
json_array_seal (node->data.array);
break;
case JSON_NODE_NULL:
break;
case JSON_NODE_VALUE:
g_return_if_fail (node->data.value != NULL);
json_value_seal (node->data.value);
break;
default:
g_assert_not_reached ();
}
node->immutable = TRUE;
}
/**
* json_node_is_immutable:
* @node: a #JsonNode
*
* Check whether the given @node has been marked as immutable by calling
* json_node_seal() on it.
*
* Since: 1.2
* Returns: %TRUE if the @node is immutable
*/
gboolean
json_node_is_immutable (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), FALSE);
return node->immutable;
}
/**
* json_node_type_name:
* @node: a #JsonNode
*
* Retrieves the user readable name of the data type contained by @node.
*
* Return value: a string containing the name of the type. The returned string
* is owned by the node and should never be modified or freed
*/
const gchar *
json_node_type_name (JsonNode *node)
{
g_return_val_if_fail (node != NULL, "(null)");
switch (node->type)
{
case JSON_NODE_OBJECT:
case JSON_NODE_ARRAY:
case JSON_NODE_NULL:
return json_node_type_get_name (node->type);
case JSON_NODE_VALUE:
if (node->data.value)
return json_value_type_get_name (node->data.value->type);
}
return "unknown";
}
const gchar *
json_node_type_get_name (JsonNodeType node_type)
{
switch (node_type)
{
case JSON_NODE_OBJECT:
return "JsonObject";
case JSON_NODE_ARRAY:
return "JsonArray";
case JSON_NODE_NULL:
return "NULL";
case JSON_NODE_VALUE:
return "Value";
default:
g_assert_not_reached ();
break;
}
return "unknown";
}
/**
* json_node_set_parent:
* @node: a #JsonNode
* @parent: (transfer none): the parent #JsonNode of @node
*
* Sets the parent #JsonNode of @node.
*
* It is an error to call this with an immutable @parent. @node may be
* immutable.
*
* Since: 0.8
*/
void
json_node_set_parent (JsonNode *node,
JsonNode *parent)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (parent == NULL ||
!json_node_is_immutable (parent));
node->parent = parent;
}
/**
* json_node_get_parent:
* @node: a #JsonNode
*
* Retrieves the parent #JsonNode of @node.
*
* Return value: (transfer none) (nullable): the parent node, or %NULL if @node
* is the root node
*/
JsonNode *
json_node_get_parent (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
return node->parent;
}
/**
* json_node_set_string:
* @node: a #JsonNode initialized to %JSON_NODE_VALUE
* @value: a string value
*
* Sets @value as the string content of the @node, replacing any existing
* content.
*
* It is an error to call this on an immutable node, or on a node which is not
* a value node.
*/
void
json_node_set_string (JsonNode *node,
const gchar *value)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_VALUE);
g_return_if_fail (!node->immutable);
if (node->data.value == NULL)
node->data.value = json_value_init (json_value_alloc (), JSON_VALUE_STRING);
else
json_value_init (node->data.value, JSON_VALUE_STRING);
json_value_set_string (node->data.value, value);
}
/**
* json_node_get_string:
* @node: a #JsonNode of type %JSON_NODE_VALUE
*
* Gets the string value stored inside a #JsonNode. If the node does not hold a
* string value, %NULL is returned.
*
* Return value: (nullable): a string value.
*/
const gchar *
json_node_get_string (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
if (JSON_NODE_TYPE (node) == JSON_NODE_NULL)
return NULL;
if (JSON_VALUE_HOLDS_STRING (node->data.value))
return json_value_get_string (node->data.value);
return NULL;
}
/**
* json_node_dup_string:
* @node: a #JsonNode of type %JSON_NODE_VALUE
*
* Gets a copy of the string value stored inside a #JsonNode. If the node does
* not hold a string value, %NULL is returned.
*
* Return value: (transfer full) (nullable): a newly allocated string
* containing a copy of the #JsonNode contents. Use g_free() to free the
* allocated resources
*/
gchar *
json_node_dup_string (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), NULL);
return g_strdup (json_node_get_string (node));
}
/**
* json_node_set_int:
* @node: a #JsonNode of type %JSON_NODE_VALUE
* @value: an integer value
*
* Sets @value as the integer content of the @node, replacing any existing
* content.
*
* It is an error to call this on an immutable node, or on a node which is not
* a value node.
*/
void
json_node_set_int (JsonNode *node,
gint64 value)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_VALUE);
g_return_if_fail (!node->immutable);
if (node->data.value == NULL)
node->data.value = json_value_init (json_value_alloc (), JSON_VALUE_INT);
else
json_value_init (node->data.value, JSON_VALUE_INT);
json_value_set_int (node->data.value, value);
}
/**
* json_node_get_int:
* @node: a #JsonNode of type %JSON_NODE_VALUE
*
* Gets the integer value stored inside a #JsonNode. If the node holds a double
* value, its integer component is returned. If the node holds a %FALSE boolean
* value, `0` is returned; otherwise a non-zero integer is returned. If the
* node holds a %JSON_NODE_NULL value or a value of another non-integer type,
* `0` is returned.
*
* Return value: an integer value.
*/
gint64
json_node_get_int (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), 0);
if (JSON_NODE_TYPE (node) == JSON_NODE_NULL)
return 0;
if (JSON_VALUE_HOLDS_INT (node->data.value))
return json_value_get_int (node->data.value);
if (JSON_VALUE_HOLDS_DOUBLE (node->data.value))
return json_value_get_double (node->data.value);
if (JSON_VALUE_HOLDS_BOOLEAN (node->data.value))
return json_value_get_boolean (node->data.value);
return 0;
}
/**
* json_node_set_double:
* @node: a #JsonNode of type %JSON_NODE_VALUE
* @value: a double value
*
* Sets @value as the double content of the @node, replacing any existing
* content.
*
* It is an error to call this on an immutable node, or on a node which is not
* a value node.
*/
void
json_node_set_double (JsonNode *node,
gdouble value)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_VALUE);
g_return_if_fail (!node->immutable);
if (node->data.value == NULL)
node->data.value = json_value_init (json_value_alloc (), JSON_VALUE_DOUBLE);
else
json_value_init (node->data.value, JSON_VALUE_DOUBLE);
json_value_set_double (node->data.value, value);
}
/**
* json_node_get_double:
* @node: a #JsonNode of type %JSON_NODE_VALUE
*
* Gets the double value stored inside a #JsonNode. If the node holds an integer
* value, it is returned as a double. If the node holds a %FALSE boolean value,
* `0.0` is returned; otherwise a non-zero double is returned. If the node holds
* a %JSON_NODE_NULL value or a value of another non-double type, `0.0` is
* returned.
*
* Return value: a double value.
*/
gdouble
json_node_get_double (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), 0.0);
if (JSON_NODE_TYPE (node) == JSON_NODE_NULL)
return 0;
if (JSON_VALUE_HOLDS_DOUBLE (node->data.value))
return json_value_get_double (node->data.value);
if (JSON_VALUE_HOLDS_INT (node->data.value))
return (gdouble) json_value_get_int (node->data.value);
if (JSON_VALUE_HOLDS_BOOLEAN (node->data.value))
return (gdouble) json_value_get_boolean (node->data.value);
return 0.0;
}
/**
* json_node_set_boolean:
* @node: a #JsonNode of type %JSON_NODE_VALUE
* @value: a boolean value
*
* Sets @value as the boolean content of the @node, replacing any existing
* content.
*
* It is an error to call this on an immutable node, or on a node which is not
* a value node.
*/
void
json_node_set_boolean (JsonNode *node,
gboolean value)
{
g_return_if_fail (JSON_NODE_IS_VALID (node));
g_return_if_fail (JSON_NODE_TYPE (node) == JSON_NODE_VALUE);
g_return_if_fail (!node->immutable);
if (node->data.value == NULL)
node->data.value = json_value_init (json_value_alloc (), JSON_VALUE_BOOLEAN);
else
json_value_init (node->data.value, JSON_VALUE_BOOLEAN);
json_value_set_boolean (node->data.value, value);
}
/**
* json_node_get_boolean:
* @node: a #JsonNode of type %JSON_NODE_VALUE
*
* Gets the boolean value stored inside a #JsonNode. If the node holds an
* integer or double value which is zero, %FALSE is returned; otherwise %TRUE
* is returned. If the node holds a %JSON_NODE_NULL value or a value of another
* non-boolean type, %FALSE is returned.
*
* Return value: a boolean value.
*/
gboolean
json_node_get_boolean (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), FALSE);
if (JSON_NODE_TYPE (node) == JSON_NODE_NULL)
return FALSE;
if (JSON_VALUE_HOLDS_BOOLEAN (node->data.value))
return json_value_get_boolean (node->data.value);
if (JSON_VALUE_HOLDS_INT (node->data.value))
return json_value_get_int (node->data.value) != 0;
if (JSON_VALUE_HOLDS_DOUBLE (node->data.value))
return json_value_get_double (node->data.value) != 0.0;
return FALSE;
}
/**
* json_node_get_node_type:
* @node: a #JsonNode
*
* Retrieves the #JsonNodeType of @node
*
* Return value: the type of the node
*
* Since: 0.8
*/
JsonNodeType
json_node_get_node_type (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), JSON_NODE_NULL);
return node->type;
}
/**
* json_node_is_null:
* @node: a #JsonNode
*
* Checks whether @node is a %JSON_NODE_NULL.
*
* A %JSON_NODE_NULL node is not the same as a %NULL #JsonNode; a
* %JSON_NODE_NULL represents a 'null' value in the JSON tree.
*
* Return value: %TRUE if the node is null
*
* Since: 0.8
*/
gboolean
json_node_is_null (JsonNode *node)
{
g_return_val_if_fail (JSON_NODE_IS_VALID (node), TRUE);
return node->type == JSON_NODE_NULL;
}
/**
* json_type_is_a:
* @sub: sub-type
* @super: super-type
*
* Check whether @sub is a sub-type of, or equal to, @super. The only sub-type
* relationship in the JSON Schema type system is that
* %WBL_PRIMITIVE_TYPE_INTEGER is a sub-type of %WBL_PRIMITIVE_TYPE_NUMBER.
*
* Formally, this function calculates: `@sub <: @super`.
*
* Reference: http://json-schema.org/latest/json-schema-core.html#rfc.section.3.5
*
* Returns: %TRUE if @sub is a sub-type of, or equal to, @super; %FALSE
* otherwise
* Since: 1.2
*/
static gboolean
json_type_is_a (JsonNode *sub,
JsonNode *super)
{
if (super->type == JSON_NODE_VALUE && sub->type == JSON_NODE_VALUE)
{
JsonValueType super_value_type, sub_value_type;
if (super->data.value == NULL || sub->data.value == NULL)
return FALSE;
super_value_type = super->data.value->type;
sub_value_type = sub->data.value->type;
return (super_value_type == sub_value_type ||
(super_value_type == JSON_VALUE_DOUBLE &&
sub_value_type == JSON_VALUE_INT));
}
return (super->type == sub->type);
}
/**
* json_string_hash:
* @key: (type utf8): a JSON string to hash
*
* Calculate a hash value for the given @key (a UTF-8 JSON string).
*
* Note: Member names are compared byte-wise, without applying any Unicode
* decomposition or normalisation. This is not explicitly mentioned in the JSON
* standard (ECMA-404), but is assumed.
*
* Returns: hash value for @key
* Since: 1.2
*/
guint
json_string_hash (gconstpointer key)
{
return g_str_hash (key);
}
/**
* json_string_equal:
* @a: (type utf8): a JSON string
* @b: (type utf8): another JSON string
*
* Check whether @a and @b are equal UTF-8 JSON strings.
*
* Returns: %TRUE if @a and @b are equal; %FALSE otherwise
* Since: 1.2
*/
gboolean
json_string_equal (gconstpointer a,
gconstpointer b)
{
return g_str_equal (a, b);
}
/**
* json_string_compare:
* @a: (type utf8): a JSON string
* @b: (type utf8): another JSON string
*
* Check whether @a and @b are equal UTF-8 JSON strings and return an ordering
* over them in strcmp() style.
*
* Returns: an integer less than zero if @a < @b, equal to zero if @a == @b, and
* greater than zero if @a > @b
* Since: 1.2
*/
gint
json_string_compare (gconstpointer a,
gconstpointer b)
{
return g_strcmp0 (a, b);
}
/**
* json_node_hash:
* @key: (type JsonNode): a JSON node to hash
*
* Calculate a hash value for the given @key (a #JsonNode).
*
* The hash is calculated over the node and its value, recursively. If the node
* is immutable, this is a fast operation; otherwise, it scales proportionally
* with the size of the node’s value (for example, with the number of members
* in the #JsonObject if this node contains an object).
*
* Returns: hash value for @key
* Since: 1.2
*/
guint
json_node_hash (gconstpointer key)
{
JsonNode *node; /* unowned */
/* These are all randomly generated and arbitrary. */
const guint value_hash = 0xc19e75ad;
const guint array_hash = 0x865acfc2;
const guint object_hash = 0x3c8f3135;
node = (JsonNode *) key;
/* XOR the hash values with a (constant) random number depending on the node’s
* type so that empty values, arrays and objects do not all collide at the
* hash value 0. */
switch (node->type)
{
case JSON_NODE_NULL:
return 0;
case JSON_NODE_VALUE:
return value_hash ^ json_value_hash (node->data.value);
case JSON_NODE_ARRAY:
return array_hash ^ json_array_hash (json_node_get_array (node));
case JSON_NODE_OBJECT:
return object_hash ^ json_object_hash (json_node_get_object (node));
default:
g_assert_not_reached ();
}
}
/**
* json_node_equal:
* @a: (type JsonNode): a JSON node
* @b: (type JsonNode): another JSON node
*
* Check whether @a and @b are equal #JsonNodes, meaning they have the same
* type and same values (checked recursively). Note that integer values are
* compared numerically, ignoring type, so a double value 4.0 is equal to the
* integer value 4.
*
* Returns: %TRUE if @a and @b are equal; %FALSE otherwise
* Since: 1.2
*/
gboolean
json_node_equal (gconstpointer a,
gconstpointer b)
{
JsonNode *node_a, *node_b; /* unowned */
node_a = (JsonNode *) a;
node_b = (JsonNode *) b;
/* Identity comparison. */
if (node_a == node_b)
return TRUE;
/* Eliminate mismatched types rapidly. */
if (!json_type_is_a (node_a, node_b) &&
!json_type_is_a (node_b, node_a))
{
return FALSE;
}
switch (node_a->type)
{
case JSON_NODE_NULL:
/* Types match already. */
return TRUE;
case JSON_NODE_ARRAY:
return json_array_equal (json_node_get_array (node_a),
json_node_get_array (node_b));
case JSON_NODE_OBJECT:
return json_object_equal (json_node_get_object (node_a),
json_node_get_object (node_b));
case JSON_NODE_VALUE:
/* Handled below. */
break;
default:
g_assert_not_reached ();
}
/* Handle values. */
switch (node_a->data.value->type)
{
case JSON_VALUE_NULL:
/* Types already match. */
return TRUE;
case JSON_VALUE_BOOLEAN:
return (json_node_get_boolean (node_a) == json_node_get_boolean (node_b));
case JSON_VALUE_STRING:
return json_string_equal (json_node_get_string (node_a),
json_node_get_string (node_b));
case JSON_VALUE_DOUBLE:
case JSON_VALUE_INT: {
gdouble val_a, val_b;
JsonValueType value_type_a, value_type_b;
value_type_a = node_a->data.value->type;
value_type_b = node_b->data.value->type;
/* Integer comparison doesn’t need to involve doubles… */
if (value_type_a == JSON_VALUE_INT &&
value_type_b == JSON_VALUE_INT)
{
return (json_node_get_int (node_a) ==
json_node_get_int (node_b));
}
/* …but everything else does. We can use bitwise double equality here,
* since we’re not doing any calculations which could introduce floating
* point error. We expect that the doubles in the JSON nodes come directly
* from strtod() or similar, so should be bitwise equal for equal string
* representations.
*
* Interesting background reading:
* http://randomascii.wordpress.com/2012/06/26/\
* doubles-are-not-floats-so-dont-compare-them/
*/
if (value_type_a == JSON_VALUE_INT)
val_a = json_node_get_int (node_a);
else
val_a = json_node_get_double (node_a);
if (value_type_b == JSON_VALUE_INT)
val_b = json_node_get_int (node_b);
else
val_b = json_node_get_double (node_b);
return (val_a == val_b);
}
case JSON_VALUE_INVALID:
default:
g_assert_not_reached ();
}
}