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/*
* Copyright © 2007, 2008 Ryan Lortie
* Copyright © 2010 Codethink Limited
*
* 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: Ryan Lortie <desrt@desrt.ca>
*/
/* Prologue {{{1 */
#include "config.h"
#include <glib/gvariant-serialiser.h>
#include "gvariant-internal.h"
#include <glib/gvariant-core.h>
#include <glib/gtestutils.h>
#include <glib/gstrfuncs.h>
#include <glib/gslice.h>
#include <glib/ghash.h>
#include <glib/gmem.h>
#include <string.h>
/**
* SECTION:gvariant
* @title: GVariant
* @short_description: strongly typed value datatype
* @see_also: GVariantType
*
* #GVariant is a variant datatype; it can contain one or more values
* along with information about the type of the values.
*
* A #GVariant may contain simple types, like an integer, or a boolean value;
* or complex types, like an array of two strings, or a dictionary of key
* value pairs. A #GVariant is also immutable: once it's been created neither
* its type nor its content can be modified further.
*
* GVariant is useful whenever data needs to be serialized, for example when
* sending method parameters in DBus, or when saving settings using GSettings.
*
* When creating a new #GVariant, you pass the data you want to store in it
* along with a string representing the type of data you wish to pass to it.
*
* For instance, if you want to create a #GVariant holding an integer value you
* can use:
*
* |[<!-- language="C" -->
* GVariant *v = g_variant_new ("u", 40);
* ]|
*
* The string "u" in the first argument tells #GVariant that the data passed to
* the constructor (40) is going to be an unsigned integer.
*
* More advanced examples of #GVariant in use can be found in documentation for
* [GVariant format strings][gvariant-format-strings-pointers].
*
* The range of possible values is determined by the type.
*
* The type system used by #GVariant is #GVariantType.
*
* #GVariant instances always have a type and a value (which are given
* at construction time). The type and value of a #GVariant instance
* can never change other than by the #GVariant itself being
* destroyed. A #GVariant cannot contain a pointer.
*
* #GVariant is reference counted using g_variant_ref() and
* g_variant_unref(). #GVariant also has floating reference counts --
* see g_variant_ref_sink().
*
* #GVariant is completely threadsafe. A #GVariant instance can be
* concurrently accessed in any way from any number of threads without
* problems.
*
* #GVariant is heavily optimised for dealing with data in serialised
* form. It works particularly well with data located in memory-mapped
* files. It can perform nearly all deserialisation operations in a
* small constant time, usually touching only a single memory page.
* Serialised #GVariant data can also be sent over the network.
*
* #GVariant is largely compatible with D-Bus. Almost all types of
* #GVariant instances can be sent over D-Bus. See #GVariantType for
* exceptions. (However, #GVariant's serialisation format is not the same
* as the serialisation format of a D-Bus message body: use #GDBusMessage,
* in the gio library, for those.)
*
* For space-efficiency, the #GVariant serialisation format does not
* automatically include the variant's length, type or endianness,
* which must either be implied from context (such as knowledge that a
* particular file format always contains a little-endian
* %G_VARIANT_TYPE_VARIANT which occupies the whole length of the file)
* or supplied out-of-band (for instance, a length, type and/or endianness
* indicator could be placed at the beginning of a file, network message
* or network stream).
*
* A #GVariant's size is limited mainly by any lower level operating
* system constraints, such as the number of bits in #gsize. For
* example, it is reasonable to have a 2GB file mapped into memory
* with #GMappedFile, and call g_variant_new_from_data() on it.
*
* For convenience to C programmers, #GVariant features powerful
* varargs-based value construction and destruction. This feature is
* designed to be embedded in other libraries.
*
* There is a Python-inspired text language for describing #GVariant
* values. #GVariant includes a printer for this language and a parser
* with type inferencing.
*
* ## Memory Use
*
* #GVariant tries to be quite efficient with respect to memory use.
* This section gives a rough idea of how much memory is used by the
* current implementation. The information here is subject to change
* in the future.
*
* The memory allocated by #GVariant can be grouped into 4 broad
* purposes: memory for serialised data, memory for the type
* information cache, buffer management memory and memory for the
* #GVariant structure itself.
*
* ## Serialised Data Memory
*
* This is the memory that is used for storing GVariant data in
* serialised form. This is what would be sent over the network or
* what would end up on disk, not counting any indicator of the
* endianness, or of the length or type of the top-level variant.
*
* The amount of memory required to store a boolean is 1 byte. 16,
* 32 and 64 bit integers and double precision floating point numbers
* use their "natural" size. Strings (including object path and
* signature strings) are stored with a nul terminator, and as such
* use the length of the string plus 1 byte.
*
* Maybe types use no space at all to represent the null value and
* use the same amount of space (sometimes plus one byte) as the
* equivalent non-maybe-typed value to represent the non-null case.
*
* Arrays use the amount of space required to store each of their
* members, concatenated. Additionally, if the items stored in an
* array are not of a fixed-size (ie: strings, other arrays, etc)
* then an additional framing offset is stored for each item. The
* size of this offset is either 1, 2 or 4 bytes depending on the
* overall size of the container. Additionally, extra padding bytes
* are added as required for alignment of child values.
*
* Tuples (including dictionary entries) use the amount of space
* required to store each of their members, concatenated, plus one
* framing offset (as per arrays) for each non-fixed-sized item in
* the tuple, except for the last one. Additionally, extra padding
* bytes are added as required for alignment of child values.
*
* Variants use the same amount of space as the item inside of the
* variant, plus 1 byte, plus the length of the type string for the
* item inside the variant.
*
* As an example, consider a dictionary mapping strings to variants.
* In the case that the dictionary is empty, 0 bytes are required for
* the serialisation.
*
* If we add an item "width" that maps to the int32 value of 500 then
* we will use 4 byte to store the int32 (so 6 for the variant
* containing it) and 6 bytes for the string. The variant must be
* aligned to 8 after the 6 bytes of the string, so that's 2 extra
* bytes. 6 (string) + 2 (padding) + 6 (variant) is 14 bytes used
* for the dictionary entry. An additional 1 byte is added to the
* array as a framing offset making a total of 15 bytes.
*
* If we add another entry, "title" that maps to a nullable string
* that happens to have a value of null, then we use 0 bytes for the
* null value (and 3 bytes for the variant to contain it along with
* its type string) plus 6 bytes for the string. Again, we need 2
* padding bytes. That makes a total of 6 + 2 + 3 = 11 bytes.
*
* We now require extra padding between the two items in the array.
* After the 14 bytes of the first item, that's 2 bytes required.
* We now require 2 framing offsets for an extra two
* bytes. 14 + 2 + 11 + 2 = 29 bytes to encode the entire two-item
* dictionary.
*
* ## Type Information Cache
*
* For each GVariant type that currently exists in the program a type
* information structure is kept in the type information cache. The
* type information structure is required for rapid deserialisation.
*
* Continuing with the above example, if a #GVariant exists with the
* type "a{sv}" then a type information struct will exist for
* "a{sv}", "{sv}", "s", and "v". Multiple uses of the same type
* will share the same type information. Additionally, all
* single-digit types are stored in read-only static memory and do
* not contribute to the writable memory footprint of a program using
* #GVariant.
*
* Aside from the type information structures stored in read-only
* memory, there are two forms of type information. One is used for
* container types where there is a single element type: arrays and
* maybe types. The other is used for container types where there
* are multiple element types: tuples and dictionary entries.
*
* Array type info structures are 6 * sizeof (void *), plus the
* memory required to store the type string itself. This means that
* on 32-bit systems, the cache entry for "a{sv}" would require 30
* bytes of memory (plus malloc overhead).
*
* Tuple type info structures are 6 * sizeof (void *), plus 4 *
* sizeof (void *) for each item in the tuple, plus the memory
* required to store the type string itself. A 2-item tuple, for
* example, would have a type information structure that consumed
* writable memory in the size of 14 * sizeof (void *) (plus type
* string) This means that on 32-bit systems, the cache entry for
* "{sv}" would require 61 bytes of memory (plus malloc overhead).
*
* This means that in total, for our "a{sv}" example, 91 bytes of
* type information would be allocated.
*
* The type information cache, additionally, uses a #GHashTable to
* store and lookup the cached items and stores a pointer to this
* hash table in static storage. The hash table is freed when there
* are zero items in the type cache.
*
* Although these sizes may seem large it is important to remember
* that a program will probably only have a very small number of
* different types of values in it and that only one type information
* structure is required for many different values of the same type.
*
* ## Buffer Management Memory
*
* #GVariant uses an internal buffer management structure to deal
* with the various different possible sources of serialised data
* that it uses. The buffer is responsible for ensuring that the
* correct call is made when the data is no longer in use by
* #GVariant. This may involve a g_free() or a g_slice_free() or
* even g_mapped_file_unref().
*
* One buffer management structure is used for each chunk of
* serialised data. The size of the buffer management structure
* is 4 * (void *). On 32-bit systems, that's 16 bytes.
*
* ## GVariant structure
*
* The size of a #GVariant structure is 6 * (void *). On 32-bit
* systems, that's 24 bytes.
*
* #GVariant structures only exist if they are explicitly created
* with API calls. For example, if a #GVariant is constructed out of
* serialised data for the example given above (with the dictionary)
* then although there are 9 individual values that comprise the
* entire dictionary (two keys, two values, two variants containing
* the values, two dictionary entries, plus the dictionary itself),
* only 1 #GVariant instance exists -- the one referring to the
* dictionary.
*
* If calls are made to start accessing the other values then
* #GVariant instances will exist for those values only for as long
* as they are in use (ie: until you call g_variant_unref()). The
* type information is shared. The serialised data and the buffer
* management structure for that serialised data is shared by the
* child.
*
* ## Summary
*
* To put the entire example together, for our dictionary mapping
* strings to variants (with two entries, as given above), we are
* using 91 bytes of memory for type information, 29 bytes of memory
* for the serialised data, 16 bytes for buffer management and 24
* bytes for the #GVariant instance, or a total of 160 bytes, plus
* malloc overhead. If we were to use g_variant_get_child_value() to
* access the two dictionary entries, we would use an additional 48
* bytes. If we were to have other dictionaries of the same type, we
* would use more memory for the serialised data and buffer
* management for those dictionaries, but the type information would
* be shared.
*/
/* definition of GVariant structure is in gvariant-core.c */
/* this is a g_return_val_if_fail() for making
* sure a (GVariant *) has the required type.
*/
#define TYPE_CHECK(value, TYPE, val) \
if G_UNLIKELY (!g_variant_is_of_type (value, TYPE)) { \
g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, \
"g_variant_is_of_type (" #value \
", " #TYPE ")"); \
return val; \
}
/* Numeric Type Constructor/Getters {{{1 */
/* < private >
* g_variant_new_from_trusted:
* @type: the #GVariantType
* @data: the data to use
* @size: the size of @data
*
* Constructs a new trusted #GVariant instance from the provided data.
* This is used to implement g_variant_new_* for all the basic types.
*
* Returns: a new floating #GVariant
*/
static GVariant *
g_variant_new_from_trusted (const GVariantType *type,
gconstpointer data,
gsize size)
{
GVariant *value;
GBytes *bytes;
bytes = g_bytes_new (data, size);
value = g_variant_new_from_bytes (type, bytes, TRUE);
g_bytes_unref (bytes);
return value;
}
/**
* g_variant_new_boolean:
* @value: a #gboolean value
*
* Creates a new boolean #GVariant instance -- either %TRUE or %FALSE.
*
* Returns: (transfer none): a floating reference to a new boolean #GVariant instance
*
* Since: 2.24
**/
GVariant *
g_variant_new_boolean (gboolean value)
{
guchar v = value;
return g_variant_new_from_trusted (G_VARIANT_TYPE_BOOLEAN, &v, 1);
}
/**
* g_variant_get_boolean:
* @value: a boolean #GVariant instance
*
* Returns the boolean value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_BOOLEAN.
*
* Returns: %TRUE or %FALSE
*
* Since: 2.24
**/
gboolean
g_variant_get_boolean (GVariant *value)
{
const guchar *data;
TYPE_CHECK (value, G_VARIANT_TYPE_BOOLEAN, FALSE);
data = g_variant_get_data (value);
return data != NULL ? *data != 0 : FALSE;
}
/* the constructors and accessors for byte, int{16,32,64}, handles and
* doubles all look pretty much exactly the same, so we reduce
* copy/pasting here.
*/
#define NUMERIC_TYPE(TYPE, type, ctype) \
GVariant *g_variant_new_##type (ctype value) { \
return g_variant_new_from_trusted (G_VARIANT_TYPE_##TYPE, \
&value, sizeof value); \
} \
ctype g_variant_get_##type (GVariant *value) { \
const ctype *data; \
TYPE_CHECK (value, G_VARIANT_TYPE_ ## TYPE, 0); \
data = g_variant_get_data (value); \
return data != NULL ? *data : 0; \
}
/**
* g_variant_new_byte:
* @value: a #guint8 value
*
* Creates a new byte #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new byte #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_byte:
* @value: a byte #GVariant instance
*
* Returns the byte value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_BYTE.
*
* Returns: a #guint8
*
* Since: 2.24
**/
NUMERIC_TYPE (BYTE, byte, guint8)
/**
* g_variant_new_int16:
* @value: a #gint16 value
*
* Creates a new int16 #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new int16 #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_int16:
* @value: a int16 #GVariant instance
*
* Returns the 16-bit signed integer value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_INT16.
*
* Returns: a #gint16
*
* Since: 2.24
**/
NUMERIC_TYPE (INT16, int16, gint16)
/**
* g_variant_new_uint16:
* @value: a #guint16 value
*
* Creates a new uint16 #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new uint16 #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_uint16:
* @value: a uint16 #GVariant instance
*
* Returns the 16-bit unsigned integer value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_UINT16.
*
* Returns: a #guint16
*
* Since: 2.24
**/
NUMERIC_TYPE (UINT16, uint16, guint16)
/**
* g_variant_new_int32:
* @value: a #gint32 value
*
* Creates a new int32 #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new int32 #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_int32:
* @value: a int32 #GVariant instance
*
* Returns the 32-bit signed integer value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_INT32.
*
* Returns: a #gint32
*
* Since: 2.24
**/
NUMERIC_TYPE (INT32, int32, gint32)
/**
* g_variant_new_uint32:
* @value: a #guint32 value
*
* Creates a new uint32 #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new uint32 #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_uint32:
* @value: a uint32 #GVariant instance
*
* Returns the 32-bit unsigned integer value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_UINT32.
*
* Returns: a #guint32
*
* Since: 2.24
**/
NUMERIC_TYPE (UINT32, uint32, guint32)
/**
* g_variant_new_int64:
* @value: a #gint64 value
*
* Creates a new int64 #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new int64 #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_int64:
* @value: a int64 #GVariant instance
*
* Returns the 64-bit signed integer value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_INT64.
*
* Returns: a #gint64
*
* Since: 2.24
**/
NUMERIC_TYPE (INT64, int64, gint64)
/**
* g_variant_new_uint64:
* @value: a #guint64 value
*
* Creates a new uint64 #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new uint64 #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_uint64:
* @value: a uint64 #GVariant instance
*
* Returns the 64-bit unsigned integer value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_UINT64.
*
* Returns: a #guint64
*
* Since: 2.24
**/
NUMERIC_TYPE (UINT64, uint64, guint64)
/**
* g_variant_new_handle:
* @value: a #gint32 value
*
* Creates a new handle #GVariant instance.
*
* By convention, handles are indexes into an array of file descriptors
* that are sent alongside a D-Bus message. If you're not interacting
* with D-Bus, you probably don't need them.
*
* Returns: (transfer none): a floating reference to a new handle #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_handle:
* @value: a handle #GVariant instance
*
* Returns the 32-bit signed integer value of @value.
*
* It is an error to call this function with a @value of any type other
* than %G_VARIANT_TYPE_HANDLE.
*
* By convention, handles are indexes into an array of file descriptors
* that are sent alongside a D-Bus message. If you're not interacting
* with D-Bus, you probably don't need them.
*
* Returns: a #gint32
*
* Since: 2.24
**/
NUMERIC_TYPE (HANDLE, handle, gint32)
/**
* g_variant_new_double:
* @value: a #gdouble floating point value
*
* Creates a new double #GVariant instance.
*
* Returns: (transfer none): a floating reference to a new double #GVariant instance
*
* Since: 2.24
**/
/**
* g_variant_get_double:
* @value: a double #GVariant instance
*
* Returns the double precision floating point value of @value.
*
* It is an error to call this function with a @value of any type
* other than %G_VARIANT_TYPE_DOUBLE.
*
* Returns: a #gdouble
*
* Since: 2.24
**/
NUMERIC_TYPE (DOUBLE, double, gdouble)
/* Container type Constructor / Deconstructors {{{1 */
/**
* g_variant_new_maybe:
* @child_type: (nullable): the #GVariantType of the child, or %NULL
* @child: (nullable): the child value, or %NULL
*
* Depending on if @child is %NULL, either wraps @child inside of a
* maybe container or creates a Nothing instance for the given @type.
*
* At least one of @child_type and @child must be non-%NULL.
* If @child_type is non-%NULL then it must be a definite type.
* If they are both non-%NULL then @child_type must be the type
* of @child.
*
* If @child is a floating reference (see g_variant_ref_sink()), the new
* instance takes ownership of @child.
*
* Returns: (transfer none): a floating reference to a new #GVariant maybe instance
*
* Since: 2.24
**/
GVariant *
g_variant_new_maybe (const GVariantType *child_type,
GVariant *child)
{
GVariantType *maybe_type;
GVariant *value;
g_return_val_if_fail (child_type == NULL || g_variant_type_is_definite
(child_type), 0);
g_return_val_if_fail (child_type != NULL || child != NULL, NULL);
g_return_val_if_fail (child_type == NULL || child == NULL ||
g_variant_is_of_type (child, child_type),
NULL);
if (child_type == NULL)
child_type = g_variant_get_type (child);
maybe_type = g_variant_type_new_maybe (child_type);
if (child != NULL)
{
GVariant **children;
gboolean trusted;
children = g_new (GVariant *, 1);
children[0] = g_variant_ref_sink (child);
trusted = g_variant_is_trusted (children[0]);
value = g_variant_new_from_children (maybe_type, children, 1, trusted);
}
else
value = g_variant_new_from_children (maybe_type, NULL, 0, TRUE);
g_variant_type_free (maybe_type);
return value;
}
/**
* g_variant_get_maybe:
* @value: a maybe-typed value
*
* Given a maybe-typed #GVariant instance, extract its value. If the
* value is Nothing, then this function returns %NULL.
*
* Returns: (nullable) (transfer full): the contents of @value, or %NULL
*
* Since: 2.24
**/
GVariant *
g_variant_get_maybe (GVariant *value)
{
TYPE_CHECK (value, G_VARIANT_TYPE_MAYBE, NULL);
if (g_variant_n_children (value))
return g_variant_get_child_value (value, 0);
return NULL;
}
/**
* g_variant_new_variant: (constructor)
* @value: a #GVariant instance
*
* Boxes @value. The result is a #GVariant instance representing a
* variant containing the original value.
*
* If @child is a floating reference (see g_variant_ref_sink()), the new
* instance takes ownership of @child.
*
* Returns: (transfer none): a floating reference to a new variant #GVariant instance
*
* Since: 2.24
**/
GVariant *
g_variant_new_variant (GVariant *value)
{
g_return_val_if_fail (value != NULL, NULL);
g_variant_ref_sink (value);
return g_variant_new_from_children (G_VARIANT_TYPE_VARIANT,
g_memdup (&value, sizeof value),
1, g_variant_is_trusted (value));
}
/**
* g_variant_get_variant:
* @value: a variant #GVariant instance
*
* Unboxes @value. The result is the #GVariant instance that was
* contained in @value.
*
* Returns: (transfer full): the item contained in the variant
*
* Since: 2.24
**/
GVariant *
g_variant_get_variant (GVariant *value)
{
TYPE_CHECK (value, G_VARIANT_TYPE_VARIANT, NULL);
return g_variant_get_child_value (value, 0);
}
/**
* g_variant_new_array:
* @child_type: (nullable): the element type of the new array
* @children: (nullable) (array length=n_children): an array of
* #GVariant pointers, the children
* @n_children: the length of @children
*
* Creates a new #GVariant array from @children.
*
* @child_type must be non-%NULL if @n_children is zero. Otherwise, the
* child type is determined by inspecting the first element of the
* @children array. If @child_type is non-%NULL then it must be a
* definite type.
*
* The items of the array are taken from the @children array. No entry
* in the @children array may be %NULL.
*
* All items in the array must have the same type, which must be the
* same as @child_type, if given.
*
* If the @children are floating references (see g_variant_ref_sink()), the
* new instance takes ownership of them as if via g_variant_ref_sink().
*
* Returns: (transfer none): a floating reference to a new #GVariant array
*
* Since: 2.24
**/
GVariant *
g_variant_new_array (const GVariantType *child_type,
GVariant * const *children,
gsize n_children)
{
GVariantType *array_type;
GVariant **my_children;
gboolean trusted;
GVariant *value;
gsize i;
g_return_val_if_fail (n_children > 0 || child_type != NULL, NULL);
g_return_val_if_fail (n_children == 0 || children != NULL, NULL);
g_return_val_if_fail (child_type == NULL ||
g_variant_type_is_definite (child_type), NULL);
my_children = g_new (GVariant *, n_children);
trusted = TRUE;
if (child_type == NULL)
child_type = g_variant_get_type (children[0]);
array_type = g_variant_type_new_array (child_type);
for (i = 0; i < n_children; i++)
{
TYPE_CHECK (children[i], child_type, NULL);
my_children[i] = g_variant_ref_sink (children[i]);
trusted &= g_variant_is_trusted (children[i]);
}
value = g_variant_new_from_children (array_type, my_children,
n_children, trusted);
g_variant_type_free (array_type);
return value;
}
/*< private >
* g_variant_make_tuple_type:
* @children: (array length=n_children): an array of GVariant *
* @n_children: the length of @children
*
* Return the type of a tuple containing @children as its items.
**/
static GVariantType *
g_variant_make_tuple_type (GVariant * const *children,
gsize n_children)
{
const GVariantType **types;
GVariantType *type;
gsize i;
types = g_new (const GVariantType *, n_children);
for (i = 0; i < n_children; i++)
types[i] = g_variant_get_type (children[i]);
type = g_variant_type_new_tuple (types, n_children);
g_free (types);
return type;
}
/**
* g_variant_new_tuple:
* @children: (array length=n_children): the items to make the tuple out of
* @n_children: the length of @children
*
* Creates a new tuple #GVariant out of the items in @children. The
* type is determined from the types of @children. No entry in the
* @children array may be %NULL.
*
* If @n_children is 0 then the unit tuple is constructed.
*
* If the @children are floating references (see g_variant_ref_sink()), the
* new instance takes ownership of them as if via g_variant_ref_sink().
*
* Returns: (transfer none): a floating reference to a new #GVariant tuple
*
* Since: 2.24
**/
GVariant *
g_variant_new_tuple (GVariant * const *children,
gsize n_children)
{
GVariantType *tuple_type;
GVariant **my_children;
gboolean trusted;
GVariant *value;
gsize i;
g_return_val_if_fail (n_children == 0 || children != NULL, NULL);
my_children = g_new (GVariant *, n_children);
trusted = TRUE;
for (i = 0; i < n_children; i++)
{
my_children[i] = g_variant_ref_sink (children[i]);
trusted &= g_variant_is_trusted (children[i]);
}
tuple_type = g_variant_make_tuple_type (children, n_children);
value = g_variant_new_from_children (tuple_type, my_children,
n_children, trusted);
g_variant_type_free (tuple_type);
return value;
}
/*< private >
* g_variant_make_dict_entry_type:
* @key: a #GVariant, the key
* @val: a #GVariant, the value
*
* Return the type of a dictionary entry containing @key and @val as its
* children.
**/
static GVariantType *
g_variant_make_dict_entry_type (GVariant *key,
GVariant *val)
{
return g_variant_type_new_dict_entry (g_variant_get_type (key),
g_variant_get_type (val));
}
/**
* g_variant_new_dict_entry: (constructor)
* @key: a basic #GVariant, the key
* @value: a #GVariant, the value
*
* Creates a new dictionary entry #GVariant. @key and @value must be
* non-%NULL. @key must be a value of a basic type (ie: not a container).
*
* If the @key or @value are floating references (see g_variant_ref_sink()),
* the new instance takes ownership of them as if via g_variant_ref_sink().
*
* Returns: (transfer none): a floating reference to a new dictionary entry #GVariant
*
* Since: 2.24
**/
GVariant *
g_variant_new_dict_entry (GVariant *key,
GVariant *value)
{
GVariantType *dict_type;
GVariant **children;
gboolean trusted;
g_return_val_if_fail (key != NULL && value != NULL, NULL);
g_return_val_if_fail (!g_variant_is_container (key), NULL);
children = g_new (GVariant *, 2);
children[0] = g_variant_ref_sink (key);
children[1] = g_variant_ref_sink (value);
trusted = g_variant_is_trusted (key) && g_variant_is_trusted (value);
dict_type = g_variant_make_dict_entry_type (key, value);
value = g_variant_new_from_children (dict_type, children, 2, trusted);
g_variant_type_free (dict_type);
return value;
}
/**
* g_variant_lookup: (skip)
* @dictionary: a dictionary #GVariant
* @key: the key to lookup in the dictionary
* @format_string: a GVariant format string
* @...: the arguments to unpack the value into
*
* Looks up a value in a dictionary #GVariant.
*
* This function is a wrapper around g_variant_lookup_value() and
* g_variant_get(). In the case that %NULL would have been returned,
* this function returns %FALSE. Otherwise, it unpacks the returned
* value and returns %TRUE.
*
* @format_string determines the C types that are used for unpacking
* the values and also determines if the values are copied or borrowed,
* see the section on
* [GVariant format strings][gvariant-format-strings-pointers].
*
* This function is currently implemented with a linear scan. If you
* plan to do many lookups then #GVariantDict may be more efficient.
*
* Returns: %TRUE if a value was unpacked
*
* Since: 2.28
*/
gboolean
g_variant_lookup (GVariant *dictionary,
const gchar *key,
const gchar *format_string,
...)
{
GVariantType *type;
GVariant *value;
/* flatten */
g_variant_get_data (dictionary);
type = g_variant_format_string_scan_type (format_string, NULL, NULL);
value = g_variant_lookup_value (dictionary, key, type);
g_variant_type_free (type);
if (value)
{
va_list ap;
va_start (ap, format_string);
g_variant_get_va (value, format_string, NULL, &ap);
g_variant_unref (value);
va_end (ap);
return TRUE;
}
else
return FALSE;
}
/**
* g_variant_lookup_value:
* @dictionary: a dictionary #GVariant
* @key: the key to lookup in the dictionary
* @expected_type: (nullable): a #GVariantType, or %NULL
*
* Looks up a value in a dictionary #GVariant.
*
* This function works with dictionaries of the type a{s*} (and equally
* well with type a{o*}, but we only further discuss the string case
* for sake of clarity).
*
* In the event that @dictionary has the type a{sv}, the @expected_type
* string specifies what type of value is expected to be inside of the
* variant. If the value inside the variant has a different type then
* %NULL is returned. In the event that @dictionary has a value type other
* than v then @expected_type must directly match the key type and it is
* used to unpack the value directly or an error occurs.
*
* In either case, if @key is not found in @dictionary, %NULL is returned.
*
* If the key is found and the value has the correct type, it is
* returned. If @expected_type was specified then any non-%NULL return
* value will have this type.
*
* This function is currently implemented with a linear scan. If you
* plan to do many lookups then #GVariantDict may be more efficient.
*
* Returns: (transfer full): the value of the dictionary key, or %NULL
*
* Since: 2.28
*/
GVariant *
g_variant_lookup_value (GVariant *dictionary,
const gchar *key,
const GVariantType *expected_type)
{
GVariantIter iter;
GVariant *entry;
GVariant *value;
g_return_val_if_fail (g_variant_is_of_type (dictionary,
G_VARIANT_TYPE ("a{s*}")) ||
g_variant_is_of_type (dictionary,
G_VARIANT_TYPE ("a{o*}")),
NULL);
g_variant_iter_init (&iter, dictionary);
while ((entry = g_variant_iter_next_value (&iter)))
{
GVariant *entry_key;
gboolean matches;
entry_key = g_variant_get_child_value (entry, 0);
matches = strcmp (g_variant_get_string (entry_key, NULL), key) == 0;
g_variant_unref (entry_key);
if (matches)
break;
g_variant_unref (entry);
}
if (entry == NULL)
return NULL;
value = g_variant_get_child_value (entry, 1);
g_variant_unref (entry);
if (g_variant_is_of_type (value, G_VARIANT_TYPE_VARIANT))
{
GVariant *tmp;
tmp = g_variant_get_variant (value);
g_variant_unref (value);
if (expected_type && !g_variant_is_of_type (tmp, expected_type))
{
g_variant_unref (tmp);
tmp = NULL;
}
value = tmp;
}
g_return_val_if_fail (expected_type == NULL || value == NULL ||
g_variant_is_of_type (value, expected_type), NULL);
return value;
}
/**
* g_variant_get_fixed_array:
* @value: a #GVariant array with fixed-sized elements
* @n_elements: (out): a pointer to the location to store the number of items
* @element_size: the size of each element
*
* Provides access to the serialised data for an array of fixed-sized
* items.
*
* @value must be an array with fixed-sized elements. Numeric types are
* fixed-size, as are tuples containing only other fixed-sized types.
*
* @element_size must be the size of a single element in the array,
* as given by the section on
* [serialized data memory][gvariant-serialised-data-memory].
*
* In particular, arrays of these fixed-sized types can be interpreted
* as an array of the given C type, with @element_size set to the size
* the appropriate type:
* - %G_VARIANT_TYPE_INT16 (etc.): #gint16 (etc.)
* - %G_VARIANT_TYPE_BOOLEAN: #guchar (not #gboolean!)
* - %G_VARIANT_TYPE_BYTE: #guint8
* - %G_VARIANT_TYPE_HANDLE: #guint32
* - %G_VARIANT_TYPE_DOUBLE: #gdouble
*
* For example, if calling this function for an array of 32-bit integers,
* you might say `sizeof(gint32)`. This value isn't used except for the purpose
* of a double-check that the form of the serialised data matches the caller's
* expectation.
*
* @n_elements, which must be non-%NULL, is set equal to the number of
* items in the array.
*
* Returns: (array length=n_elements) (transfer none): a pointer to
* the fixed array
*
* Since: 2.24
**/
gconstpointer
g_variant_get_fixed_array (GVariant *value,
gsize *n_elements,
gsize element_size)
{
GVariantTypeInfo *array_info;
gsize array_element_size;
gconstpointer data;
gsize size;
TYPE_CHECK (value, G_VARIANT_TYPE_ARRAY, NULL);
g_return_val_if_fail (n_elements != NULL, NULL);
g_return_val_if_fail (element_size > 0, NULL);
array_info = g_variant_get_type_info (value);
g_variant_type_info_query_element (array_info, NULL, &array_element_size);
g_return_val_if_fail (array_element_size, NULL);
if G_UNLIKELY (array_element_size != element_size)
{
if (array_element_size)
g_critical ("g_variant_get_fixed_array: assertion "
"'g_variant_array_has_fixed_size (value, element_size)' "
"failed: array size %"G_GSIZE_FORMAT" does not match "
"given element_size %"G_GSIZE_FORMAT".",
array_element_size, element_size);
else
g_critical ("g_variant_get_fixed_array: assertion "
"'g_variant_array_has_fixed_size (value, element_size)' "
"failed: array does not have fixed size.");
}
data = g_variant_get_data (value);
size = g_variant_get_size (value);
if (size % element_size)
*n_elements = 0;
else
*n_elements = size / element_size;
if (*n_elements)
return data;
return NULL;
}
/**
* g_variant_new_fixed_array:
* @element_type: the #GVariantType of each element
* @elements: a pointer to the fixed array of contiguous elements
* @n_elements: the number of elements
* @element_size: the size of each element
*
* Constructs a new array #GVariant instance, where the elements are
* of @element_type type.
*
* @elements must be an array with fixed-sized elements. Numeric types are
* fixed-size as are tuples containing only other fixed-sized types.
*
* @element_size must be the size of a single element in the array.
* For example, if calling this function for an array of 32-bit integers,
* you might say sizeof(gint32). This value isn't used except for the purpose
* of a double-check that the form of the serialised data matches the caller's
* expectation.
*
* @n_elements must be the length of the @elements array.
*
* Returns: (transfer none): a floating reference to a new array #GVariant instance
*
* Since: 2.32
**/
GVariant *
g_variant_new_fixed_array (const GVariantType *element_type,
gconstpointer elements,
gsize n_elements,
gsize element_size)
{
GVariantType *array_type;
gsize array_element_size;
GVariantTypeInfo *array_info;
GVariant *value;
gpointer data;
g_return_val_if_fail (g_variant_type_is_definite (element_type), NULL);
g_return_val_if_fail (element_size > 0, NULL);
array_type = g_variant_type_new_array (element_type);
array_info = g_variant_type_info_get (array_type);
g_variant_type_info_query_element (array_info, NULL, &array_element_size);
if G_UNLIKELY (array_element_size != element_size)
{
if (array_element_size)
g_critical ("g_variant_new_fixed_array: array size %" G_GSIZE_FORMAT
" does not match given element_size %" G_GSIZE_FORMAT ".",
array_element_size, element_size);
else
g_critical ("g_variant_get_fixed_array: array does not have fixed size.");
return NULL;
}
data = g_memdup (elements, n_elements * element_size);
value = g_variant_new_from_data (array_type, data,
n_elements * element_size,
FALSE, g_free, data);
g_variant_type_free (array_type);
g_variant_type_info_unref (array_info);
return value;
}
/* String type constructor/getters/validation {{{1 */
/**
* g_variant_new_string:
* @string: a normal UTF-8 nul-terminated string
*
* Creates a string #GVariant with the contents of @string.
*
* @string must be valid UTF-8, and must not be %NULL. To encode
* potentially-%NULL strings, use g_variant_new() with `ms` as the
* [format string][gvariant-format-strings-maybe-types].
*
* Returns: (transfer none): a floating reference to a new string #GVariant instance
*
* Since: 2.24
**/
GVariant *
g_variant_new_string (const gchar *string)
{
g_return_val_if_fail (string != NULL, NULL);
g_return_val_if_fail (g_utf8_validate (string, -1, NULL), NULL);
return g_variant_new_from_trusted (G_VARIANT_TYPE_STRING,
string, strlen (string) + 1);
}
/**
* g_variant_new_take_string: (skip)
* @string: a normal UTF-8 nul-terminated string
*
* Creates a string #GVariant with the contents of @string.
*
* @string must be valid UTF-8, and must not be %NULL. To encode
* potentially-%NULL strings, use this with g_variant_new_maybe().
*
* This function consumes @string. g_free() will be called on @string
* when it is no longer required.
*
* You must not modify or access @string in any other way after passing
* it to this function. It is even possible that @string is immediately
* freed.
*
* Returns: (transfer none): a floating reference to a new string
* #GVariant instance
*
* Since: 2.38
**/
GVariant *
g_variant_new_take_string (gchar *string)
{
GVariant *value;
GBytes *bytes;
g_return_val_if_fail (string != NULL, NULL);
g_return_val_if_fail (g_utf8_validate (string, -1, NULL), NULL);
bytes = g_bytes_new_take (string, strlen (string) + 1);
value = g_variant_new_from_bytes (G_VARIANT_TYPE_STRING, bytes, TRUE);
g_bytes_unref (bytes);
return value;
}
/**
* g_variant_new_printf: (skip)
* @format_string: a printf-style format string
* @...: arguments for @format_string
*
* Creates a string-type GVariant using printf formatting.
*
* This is similar to calling g_strdup_printf() and then
* g_variant_new_string() but it saves a temporary variable and an
* unnecessary copy.
*
* Returns: (transfer none): a floating reference to a new string
* #GVariant instance
*
* Since: 2.38
**/
GVariant *
g_variant_new_printf (const gchar *format_string,
...)
{
GVariant *value;
GBytes *bytes;
gchar *string;
va_list ap;
g_return_val_if_fail (format_string != NULL, NULL);
va_start (ap, format_string);
string = g_strdup_vprintf (format_string, ap);
va_end (ap);
bytes = g_bytes_new_take (string, strlen (string) + 1);
value = g_variant_new_from_bytes (G_VARIANT_TYPE_STRING, bytes, TRUE);
g_bytes_unref (bytes);
return value;
}
/**
* g_variant_new_object_path:
* @object_path: a normal C nul-terminated string
*
* Creates a D-Bus object path #GVariant with the contents of @string.
* @string must be a valid D-Bus object path. Use
* g_variant_is_object_path() if you're not sure.
*
* Returns: (transfer none): a floating reference to a new object path #GVariant instance
*
* Since: 2.24
**/
GVariant *
g_variant_new_object_path (const gchar *object_path)
{
g_return_val_if_fail (g_variant_is_object_path (object_path), NULL);
return g_variant_new_from_trusted (G_VARIANT_TYPE_OBJECT_PATH,
object_path, strlen (object_path) + 1);
}
/**
* g_variant_is_object_path:
* @string: a normal C nul-terminated string
*
* Determines if a given string is a valid D-Bus object path. You
* should ensure that a string is a valid D-Bus object path before
* passing it to g_variant_new_object_path().
*
* A valid object path starts with '/' followed by zero or more
* sequences of characters separated by '/' characters. Each sequence
* must contain only the characters "[A-Z][a-z][0-9]_". No sequence
* (including the one following the final '/' character) may be empty.
*
* Returns: %TRUE if @string is a D-Bus object path
*
* Since: 2.24
**/
gboolean
g_variant_is_object_path (const gchar *string)
{
g_return_val_if_fail (string != NULL, FALSE);
return g_variant_serialiser_is_object_path (string, strlen (string) + 1);
}
/**
* g_variant_new_signature:
* @signature: a normal C nul-terminated string
*
* Creates a D-Bus type signature #GVariant with the contents of
* @string. @string must be a valid D-Bus type signature. Use
* g_variant_is_signature() if you're not sure.
*
* Returns: (transfer none): a floating reference to a new signature #GVariant instance
*
* Since: 2.24
**/
GVariant *
g_variant_new_signature (const gchar *signature)
{
g_return_val_if_fail (g_variant_is_signature (signature), NULL);
return g_variant_new_from_trusted (G_VARIANT_TYPE_SIGNATURE,
signature, strlen (signature) + 1);
}
/**
* g_variant_is_signature:
* @string: a normal C nul-terminated string
*
* Determines if a given string is a valid D-Bus type signature. You
* should ensure that a string is a valid D-Bus type signature before
* passing it to g_variant_new_signature().
*
* D-Bus type signatures consist of zero or more definite #GVariantType
* strings in sequence.
*
* Returns: %TRUE if @string is a D-Bus type signature
*
* Since: 2.24
**/
gboolean
g_variant_is_signature (const gchar *string)
{
g_return_val_if_fail (string != NULL, FALSE);
return g_variant_serialiser_is_signature (string, strlen (string) + 1);
}
/**
* g_variant_get_string:
* @value: a string #GVariant instance
* @length: (optional) (default 0) (out): a pointer to a #gsize,
* to store the length
*
* Returns the string value of a #GVariant instance with a string
* type. This includes the types %G_VARIANT_TYPE_STRING,
* %G_VARIANT_TYPE_OBJECT_PATH and %G_VARIANT_TYPE_SIGNATURE.
*
* The string will always be UTF-8 encoded, and will never be %NULL.
*
* If @length is non-%NULL then the length of the string (in bytes) is
* returned there. For trusted values, this information is already
* known. For untrusted values, a strlen() will be performed.
*
* It is an error to call this function with a @value of any type
* other than those three.
*
* The return value remains valid as long as @value exists.
*
* Returns: (transfer none): the constant string, UTF-8 encoded
*
* Since: 2.24
**/
const gchar *
g_variant_get_string (GVariant *value,
gsize *length)
{
gconstpointer data;
gsize size;
g_return_val_if_fail (value != NULL, NULL);
g_return_val_if_fail (
g_variant_is_of_type (value, G_VARIANT_TYPE_STRING) ||
g_variant_is_of_type (value, G_VARIANT_TYPE_OBJECT_PATH) ||
g_variant_is_of_type (value, G_VARIANT_TYPE_SIGNATURE), NULL);
data = g_variant_get_data (value);
size = g_variant_get_size (value);
if (!g_variant_is_trusted (value))
{
switch (g_variant_classify (value))
{
case G_VARIANT_CLASS_STRING:
if (g_variant_serialiser_is_string (data, size))
break;
data = "";
size = 1;
break;
case G_VARIANT_CLASS_OBJECT_PATH:
if (g_variant_serialiser_is_object_path (data, size))
break;
data = "/";
size = 2;
break;
case G_VARIANT_CLASS_SIGNATURE:
if (g_variant_serialiser_is_signature (data, size))
break;
data = "";
size = 1;
break;
default:
g_assert_not_reached ();
}
}
if (length)
*length = size - 1;
return data;
}
/**
* g_variant_dup_string:
* @value: a string #GVariant instance
* @length: (out): a pointer to a #gsize, to store the length
*
* Similar to g_variant_get_string() except that instead of returning
* a constant string, the string is duplicated.
*
* The string will always be UTF-8 encoded.
*
* The return value must be freed using g_free().
*
* Returns: (transfer full): a newly allocated string, UTF-8 encoded
*
* Since: 2.24
**/
gchar *
g_variant_dup_string (GVariant *value,
gsize *length)
{
return g_strdup (g_variant_get_string (value, length));
}
/**
* g_variant_new_strv:
* @strv: (array length=length) (element-type utf8): an array of strings
* @length: the length of @strv, or -1
*
* Constructs an array of strings #GVariant from the given array of
* strings.
*
* If @length is -1 then @strv is %NULL-terminated.
*
* Returns: (transfer none): a new floating #GVariant instance
*
* Since: 2.24
**/
GVariant *
g_variant_new_strv (const gchar * const *strv,
gssize length)
{
GVariant **strings;
gsize i;
g_return_val_if_fail (length == 0 || strv != NULL, NULL);
if (length < 0)
length = g_strv_length ((gchar **) strv);
strings = g_new (GVariant *, length);
for (i = 0; i < length; i++)
strings[i] = g_variant_ref_sink (g_variant_new_string (strv[i]));
return g_variant_new_from_children (G_VARIANT_TYPE_STRING_ARRAY,
strings, length, TRUE);
}
/**
* g_variant_get_strv:
* @value: an array of strings #GVariant
* @length: (out) (optional): the length of the result, or %NULL
*
* Gets the contents of an array of strings #GVariant. This call
* makes a shallow copy; the return result should be released with
* g_free(), but the individual strings must not be modified.
*
* If @length is non-%NULL then the number of elements in the result
* is stored there. In any case, the resulting array will be
* %NULL-terminated.
*
* For an empty array, @length will be set to 0 and a pointer to a
* %NULL pointer will be returned.
*
* Returns: (array length=length zero-terminated=1) (transfer container): an array of constant strings
*
* Since: 2.24
**/
const gchar **
g_variant_get_strv (GVariant *value,
gsize *length)
{
const gchar **strv;
gsize n;
gsize i;
TYPE_CHECK (value, G_VARIANT_TYPE_STRING_ARRAY, NULL);
g_variant_get_data (value);
n = g_variant_n_children (value);
strv = g_new (const gchar *, n + 1);
for (i = 0; i < n; i++)
{
GVariant *string;
string = g_variant_get_child_value (value, i);
strv[i] = g_variant_get_string (string, NULL);
g_variant_unref (string);
}
strv[i] = NULL;
if (length)
*length = n;
return strv;
}
/**
* g_variant_dup_strv:
* @value: an array of strings #GVariant
* @length: (out) (optional): the length of the result, or %NULL
*
* Gets the contents of an array of strings #GVariant. This call
* makes a deep copy; the return result should be released with
* g_strfreev().
*
* If @length is non-%NULL then the number of elements in the result
* is stored there. In any case, the resulting array will be
* %NULL-terminated.
*
* For an empty array, @length will be set to 0 and a pointer to a
* %NULL pointer will be returned.
*
* Returns: (array length=length zero-terminated=1) (transfer full): an array of strings
*
* Since: 2.24
**/
gchar **
g_variant_dup_strv (GVariant *value,
gsize *length)
{
gchar **strv;
gsize n;
gsize i;
TYPE_CHECK (value, G_VARIANT_TYPE_STRING_ARRAY, NULL);
n = g_variant_n_children (value);
strv = g_new (gchar *, n + 1);
for (i = 0; i < n; i++)
{
GVariant *string;
string = g_variant_get_child_value (value, i);
strv[i] = g_variant_dup_string (string, NULL);
g_variant_unref (string);
}
strv[i] = NULL;
if (length)
*length = n;
return strv;
}
/**
* g_variant_new_objv:
* @strv: (array length=length) (element-type utf8): an array of strings
* @length: the length of @strv, or -1
*
* Constructs an array of object paths #GVariant from the given array of
* strings.
*
* Each string must be a valid #GVariant object path; see
* g_variant_is_object_path().
*
* If @length is -1 then @strv is %NULL-terminated.
*
* Returns: (transfer none): a new floating #GVariant instance
*
* Since: 2.30
**/
GVariant *
g_variant_new_objv (const gchar * const *strv,
gssize length)
{
GVariant **strings;
gsize i;
g_return_val_if_fail (length == 0 || strv != NULL, NULL);
if (length < 0)
length = g_strv_length ((gchar **) strv);
strings = g_new (GVariant *, length);
for (i = 0; i < length; i++)
strings[i] = g_variant_ref_sink (g_variant_new_object_path (strv[i]));
return g_variant_new_from_children (G_VARIANT_TYPE_OBJECT_PATH_ARRAY,
strings, length, TRUE);
}
/**
* g_variant_get_objv:
* @value: an array of object paths #GVariant
* @length: (out) (optional): the length of the result, or %NULL
*
* Gets the contents of an array of object paths #GVariant. This call
* makes a shallow copy; the return result should be released with
* g_free(), but the individual strings must not be modified.
*
* If @length is non-%NULL then the number of elements in the result
* is stored there. In any case, the resulting array will be
* %NULL-terminated.
*
* For an empty array, @length will be set to 0 and a pointer to a
* %NULL pointer will be returned.
*
* Returns: (array length=length zero-terminated=1) (transfer container): an array of constant strings
*
* Since: 2.30
**/
const gchar **
g_variant_get_objv (GVariant *value,
gsize *length)
{
const gchar **strv;
gsize n;
gsize i;
TYPE_CHECK (value, G_VARIANT_TYPE_OBJECT_PATH_ARRAY, NULL);
g_variant_get_data (value);
n = g_variant_n_children (value);
strv = g_new (const gchar *, n + 1);
for (i = 0; i < n; i++)
{
GVariant *string;
string = g_variant_get_child_value (value, i);
strv[i] = g_variant_get_string (string, NULL);
g_variant_unref (string);
}
strv[i] = NULL;
if (length)
*length = n;
return strv;
}
/**
* g_variant_dup_objv:
* @value: an array of object paths #GVariant
* @length: (out) (optional): the length of the result, or %NULL
*
* Gets the contents of an array of object paths #GVariant. This call
* makes a deep copy; the return result should be released with
* g_strfreev().
*
* If @length is non-%NULL then the number of elements in the result
* is stored there. In any case, the resulting array will be
* %NULL-terminated.
*
* For an empty array, @length will be set to 0 and a pointer to a
* %NULL pointer will be returned.
*
* Returns: (array length=length zero-terminated=1) (transfer full): an array of strings
*
* Since: 2.30
**/
gchar **
g_variant_dup_objv (GVariant *value,
gsize *length)
{
gchar **strv;
gsize n;
gsize i;
TYPE_CHECK (value, G_VARIANT_TYPE_OBJECT_PATH_ARRAY, NULL);
n = g_variant_n_children (value);
strv = g_new (gchar *, n + 1);
for (i = 0; i < n; i++)
{
GVariant *string;
string = g_variant_get_child_value (value, i);
strv[i] = g_variant_dup_string (string, NULL);
g_variant_unref (string);
}
strv[i] = NULL;
if (length)
*length = n;
return strv;
}
/**
* g_variant_new_bytestring:
* @string: (array zero-terminated=1) (element-type guint8): a normal
* nul-terminated string in no particular encoding
*
* Creates an array-of-bytes #GVariant with the contents of @string.
* This function is just like g_variant_new_string() except that the
* string need not be valid UTF-8.
*
* The nul terminator character at the end of the string is stored in
* the array.
*
* Returns: (transfer none): a floating reference to a new bytestring #GVariant instance
*
* Since: 2.26
**/
GVariant *
g_variant_new_bytestring (const gchar *string)
{
g_return_val_if_fail (string != NULL, NULL);
return g_variant_new_from_trusted (G_VARIANT_TYPE_BYTESTRING,
string, strlen (string) + 1);
}
/**
* g_variant_get_bytestring:
* @value: an array-of-bytes #GVariant instance
*
* Returns the string value of a #GVariant instance with an
* array-of-bytes type. The string has no particular encoding.
*
* If the array does not end with a nul terminator character, the empty
* string is returned. For this reason, you can always trust that a
* non-%NULL nul-terminated string will be returned by this function.
*
* If the array contains a nul terminator character somewhere other than
* the last byte then the returned string is the string, up to the first
* such nul character.
*
* g_variant_get_fixed_array() should be used instead if the array contains
* arbitrary data that could not be nul-terminated or could contain nul bytes.
*
* It is an error to call this function with a @value that is not an
* array of bytes.
*
* The return value remains valid as long as @value exists.
*
* Returns: (transfer none) (array zero-terminated=1) (element-type guint8):
* the constant string
*
* Since: 2.26
**/
const gchar *
g_variant_get_bytestring (GVariant *value)
{
const gchar *string;
gsize size;
TYPE_CHECK (value, G_VARIANT_TYPE_BYTESTRING, NULL);
/* Won't be NULL since this is an array type */
string = g_variant_get_data (value);
size = g_variant_get_size (value);
if (size && string[size - 1] == '\0')
return string;
else
return "";
}
/**
* g_variant_dup_bytestring:
* @value: an array-of-bytes #GVariant instance
* @length: (out) (optional) (default NULL): a pointer to a #gsize, to store
* the length (not including the nul terminator)
*
* Similar to g_variant_get_bytestring() except that instead of
* returning a constant string, the string is duplicated.
*
* The return value must be freed using g_free().
*
* Returns: (transfer full) (array zero-terminated=1 length=length) (element-type guint8):
* a newly allocated string
*
* Since: 2.26
**/
gchar *
g_variant_dup_bytestring (GVariant *value,
gsize *length)
{
const gchar *original = g_variant_get_bytestring (value);
gsize size;
/* don't crash in case get_bytestring() had an assert failure */
if (original == NULL)
return NULL;
size = strlen (original);
if (length)
*length = size;
return g_memdup (original, size + 1);
}
/**
* g_variant_new_bytestring_array:
* @strv: (array length=length): an array of strings
* @length: the length of @strv, or -1
*
* Constructs an array of bytestring #GVariant from the given array of
* strings.
*
* If @length is -1 then @strv is %NULL-terminated.
*
* Returns: (transfer none): a new floating #GVariant instance
*
* Since: 2.26
**/
GVariant *
g_variant_new_bytestring_array (const gchar * const *strv,
gssize length)
{
GVariant **strings;
gsize i;
g_return_val_if_fail (length == 0 || strv != NULL, NULL);
if (length < 0)
length = g_strv_length ((gchar **) strv);
strings = g_new (GVariant *, length);
for (i = 0; i < length; i++)
strings[i] = g_variant_ref_sink (g_variant_new_bytestring (strv[i]));
return g_variant_new_from_children (G_VARIANT_TYPE_BYTESTRING_ARRAY,
strings, length, TRUE);
}
/**
* g_variant_get_bytestring_array:
* @value: an array of array of bytes #GVariant ('aay')
* @length: (out) (optional): the length of the result, or %NULL
*
* Gets the contents of an array of array of bytes #GVariant. This call
* makes a shallow copy; the return result should be released with
* g_free(), but the individual strings must not be modified.
*
* If @length is non-%NULL then the number of elements in the result is
* stored there. In any case, the resulting array will be
* %NULL-terminated.
*
* For an empty array, @length will be set to 0 and a pointer to a
* %NULL pointer will be returned.
*
* Returns: (array length=length) (transfer container): an array of constant strings
*
* Since: 2.26
**/
const gchar **
g_variant_get_bytestring_array (GVariant *value,
gsize *length)
{
const gchar **strv;
gsize n;
gsize i;
TYPE_CHECK (value, G_VARIANT_TYPE_BYTESTRING_ARRAY, NULL);
g_variant_get_data (value);
n = g_variant_n_children (value);
strv = g_new (const gchar *, n + 1);
for (i = 0; i < n; i++)
{
GVariant *string;
string = g_variant_get_child_value (value, i);
strv[i] = g_variant_get_bytestring (string);
g_variant_unref (string);
}
strv[i] = NULL;
if (length)
*length = n;
return strv;
}
/**
* g_variant_dup_bytestring_array:
* @value: an array of array of bytes #GVariant ('aay')
* @length: (out) (optional): the length of the result, or %NULL
*
* Gets the contents of an array of array of bytes #GVariant. This call
* makes a deep copy; the return result should be released with
* g_strfreev().
*
* If @length is non-%NULL then the number of elements in the result is
* stored there. In any case, the resulting array will be
* %NULL-terminated.
*
* For an empty array, @length will be set to 0 and a pointer to a
* %NULL pointer will be returned.
*
* Returns: (array length=length) (transfer full): an array of strings
*
* Since: 2.26
**/
gchar **
g_variant_dup_bytestring_array (GVariant *value,
gsize *length)
{
gchar **strv;
gsize n;
gsize i;
TYPE_CHECK (value, G_VARIANT_TYPE_BYTESTRING_ARRAY, NULL);
g_variant_get_data (value);
n = g_variant_n_children (value);
strv = g_new (gchar *, n + 1);
for (i = 0; i < n; i++)
{
GVariant *string;
string = g_variant_get_child_value (value, i);
strv[i] = g_variant_dup_bytestring (string, NULL);
g_variant_unref (string);
}
strv[i] = NULL;
if (length)
*length = n;
return strv;
}
/* Type checking and querying {{{1 */
/**
* g_variant_get_type:
* @value: a #GVariant
*
* Determines the type of @value.
*
* The return value is valid for the lifetime of @value and must not
* be freed.
*
* Returns: a #GVariantType
*
* Since: 2.24
**/
const GVariantType *
g_variant_get_type (GVariant *value)
{
GVariantTypeInfo *type_info;
g_return_val_if_fail (value != NULL, NULL);
type_info = g_variant_get_type_info (value);
return (GVariantType *) g_variant_type_info_get_type_string (type_info);
}
/**
* g_variant_get_type_string:
* @value: a #GVariant
*
* Returns the type string of @value. Unlike the result of calling
* g_variant_type_peek_string(), this string is nul-terminated. This
* string belongs to #GVariant and must not be freed.
*
* Returns: the type string for the type of @value
*
* Since: 2.24
**/
const gchar *
g_variant_get_type_string (GVariant *value)
{
GVariantTypeInfo *type_info;
g_return_val_if_fail (value != NULL, NULL);
type_info = g_variant_get_type_info (value);
return g_variant_type_info_get_type_string (type_info);
}
/**
* g_variant_is_of_type:
* @value: a #GVariant instance
* @type: a #GVariantType
*
* Checks if a value has a type matching the provided type.
*
* Returns: %TRUE if the type of @value matches @type
*
* Since: 2.24
**/
gboolean
g_variant_is_of_type (GVariant *value,
const GVariantType *type)
{
return g_variant_type_is_subtype_of (g_variant_get_type (value), type);
}
/**
* g_variant_is_container:
* @value: a #GVariant instance
*
* Checks if @value is a container.
*
* Returns: %TRUE if @value is a container
*
* Since: 2.24
*/
gboolean
g_variant_is_container (GVariant *value)
{
return g_variant_type_is_container (g_variant_get_type (value));
}
/**
* g_variant_classify:
* @value: a #GVariant
*
* Classifies @value according to its top-level type.
*
* Returns: the #GVariantClass of @value
*
* Since: 2.24
**/
/**
* GVariantClass:
* @G_VARIANT_CLASS_BOOLEAN: The #GVariant is a boolean.
* @G_VARIANT_CLASS_BYTE: The #GVariant is a byte.
* @G_VARIANT_CLASS_INT16: The #GVariant is a signed 16 bit integer.
* @G_VARIANT_CLASS_UINT16: The #GVariant is an unsigned 16 bit integer.
* @G_VARIANT_CLASS_INT32: The #GVariant is a signed 32 bit integer.
* @G_VARIANT_CLASS_UINT32: The #GVariant is an unsigned 32 bit integer.
* @G_VARIANT_CLASS_INT64: The #GVariant is a signed 64 bit integer.
* @G_VARIANT_CLASS_UINT64: The #GVariant is an unsigned 64 bit integer.
* @G_VARIANT_CLASS_HANDLE: The #GVariant is a file handle index.
* @G_VARIANT_CLASS_DOUBLE: The #GVariant is a double precision floating
* point value.
* @G_VARIANT_CLASS_STRING: The #GVariant is a normal string.
* @G_VARIANT_CLASS_OBJECT_PATH: The #GVariant is a D-Bus object path
* string.
* @G_VARIANT_CLASS_SIGNATURE: The #GVariant is a D-Bus signature string.
* @G_VARIANT_CLASS_VARIANT: The #GVariant is a variant.
* @G_VARIANT_CLASS_MAYBE: The #GVariant is a maybe-typed value.
* @G_VARIANT_CLASS_ARRAY: The #GVariant is an array.
* @G_VARIANT_CLASS_TUPLE: The #GVariant is a tuple.
* @G_VARIANT_CLASS_DICT_ENTRY: The #GVariant is a dictionary entry.
*
* The range of possible top-level types of #GVariant instances.
*
* Since: 2.24
**/
GVariantClass
g_variant_classify (GVariant *value)
{
g_return_val_if_fail (value != NULL, 0);
return *g_variant_get_type_string (value);
}
/* Pretty printer {{{1 */
/* This function is not introspectable because if @string is NULL,
@returns is (transfer full), otherwise it is (transfer none), which
is not supported by GObjectIntrospection */
/**
* g_variant_print_string: (skip)
* @value: a #GVariant
* @string: (nullable) (default NULL): a #GString, or %NULL
* @type_annotate: %TRUE if type information should be included in
* the output
*
* Behaves as g_variant_print(), but operates on a #GString.
*
* If @string is non-%NULL then it is appended to and returned. Else,
* a new empty #GString is allocated and it is returned.
*
* Returns: a #GString containing the string
*
* Since: 2.24
**/
GString *
g_variant_print_string (GVariant *value,
GString *string,
gboolean type_annotate)
{
if G_UNLIKELY (string == NULL)
string = g_string_new (NULL);
switch (g_variant_classify (value))
{
case G_VARIANT_CLASS_MAYBE:
if (type_annotate)
g_string_append_printf (string, "@%s ",
g_variant_get_type_string (value));
if (g_variant_n_children (value))
{
gchar *printed_child;
GVariant *element;
/* Nested maybes:
*
* Consider the case of the type "mmi". In this case we could
* write "just just 4", but "4" alone is totally unambiguous,
* so we try to drop "just" where possible.
*
* We have to be careful not to always drop "just", though,
* since "nothing" needs to be distinguishable from "just
* nothing". The case where we need to ensure we keep the
* "just" is actually exactly the case where we have a nested
* Nothing.
*
* Instead of searching for that nested Nothing, we just print
* the contained value into a separate string and see if we
* end up with "nothing" at the end of it. If so, we need to
* add "just" at our level.
*/
element = g_variant_get_child_value (value, 0);
printed_child = g_variant_print (element, FALSE);
g_variant_unref (element);
if (g_str_has_suffix (printed_child, "nothing"))
g_string_append (string, "just ");
g_string_append (string, printed_child);
g_free (printed_child);
}
else
g_string_append (string, "nothing");
break;
case G_VARIANT_CLASS_ARRAY:
/* it's an array so the first character of the type string is 'a'
*
* if the first two characters are 'ay' then it's a bytestring.
* under certain conditions we print those as strings.
*/
if (g_variant_get_type_string (value)[1] == 'y')
{
const gchar *str;
gsize size;
gsize i;
/* first determine if it is a byte string.
* that's when there's a single nul character: at the end.
*/
str = g_variant_get_data (value);
size = g_variant_get_size (value);
for (i = 0; i < size; i++)
if (str[i] == '\0')
break;
/* first nul byte is the last byte -> it's a byte string. */
if (i == size - 1)
{
gchar *escaped = g_strescape (str, NULL);
/* use double quotes only if a ' is in the string */
if (strchr (str, '\''))
g_string_append_printf (string, "b\"%s\"", escaped);
else
g_string_append_printf (string, "b'%s'", escaped);
g_free (escaped);
break;
}
else
{
/* fall through and handle normally... */
}
}
/*
* if the first two characters are 'a{' then it's an array of
* dictionary entries (ie: a dictionary) so we print that
* differently.
*/
if (g_variant_get_type_string (value)[1] == '{')
/* dictionary */
{
const gchar *comma = "";
gsize n, i;
if ((n = g_variant_n_children (value)) == 0)
{
if (type_annotate)
g_string_append_printf (string, "@%s ",
g_variant_get_type_string (value));
g_string_append (string, "{}");
break;
}
g_string_append_c (string, '{');
for (i = 0; i < n; i++)
{
GVariant *entry, *key, *val;
g_string_append (string, comma);
comma = ", ";
entry = g_variant_get_child_value (value, i);
key = g_variant_get_child_value (entry, 0);
val = g_variant_get_child_value (entry, 1);
g_variant_unref (entry);
g_variant_print_string (key, string, type_annotate);
g_variant_unref (key);
g_string_append (string, ": ");
g_variant_print_string (val, string, type_annotate);
g_variant_unref (val);
type_annotate = FALSE;
}
g_string_append_c (string, '}');
}
else
/* normal (non-dictionary) array */
{
const gchar *comma = "";
gsize n, i;
if ((n = g_variant_n_children (value)) == 0)
{
if (type_annotate)
g_string_append_printf (string, "@%s ",
g_variant_get_type_string (value));
g_string_append (string, "[]");
break;
}
g_string_append_c (string, '[');
for (i = 0; i < n; i++)
{
GVariant *element;
g_string_append (string, comma);
comma = ", ";
element = g_variant_get_child_value (value, i);
g_variant_print_string (element, string, type_annotate);
g_variant_unref (element);
type_annotate = FALSE;
}
g_string_append_c (string, ']');
}
break;
case G_VARIANT_CLASS_TUPLE:
{
gsize n, i;
n = g_variant_n_children (value);
g_string_append_c (string, '(');
for (i = 0; i < n; i++)
{
GVariant *element;
element = g_variant_get_child_value (value, i);
g_variant_print_string (element, string, type_annotate);
g_string_append (string, ", ");
g_variant_unref (element);
}
/* for >1 item: remove final ", "
* for 1 item: remove final " ", but leave the ","
* for 0 items: there is only "(", so remove nothing
*/
g_string_truncate (string, string->len - (n > 0) - (n > 1));
g_string_append_c (string, ')');
}
break;
case G_VARIANT_CLASS_DICT_ENTRY:
{
GVariant *element;
g_string_append_c (string, '{');
element = g_variant_get_child_value (value, 0);
g_variant_print_string (element, string, type_annotate);
g_variant_unref (element);
g_string_append (string, ", ");
element = g_variant_get_child_value (value, 1);
g_variant_print_string (element, string, type_annotate);
g_variant_unref (element);
g_string_append_c (string, '}');
}
break;
case G_VARIANT_CLASS_VARIANT:
{
GVariant *child = g_variant_get_variant (value);
/* Always annotate types in nested variants, because they are
* (by nature) of variable type.
*/
g_string_append_c (string, '<');
g_variant_print_string (child, string, TRUE);
g_string_append_c (string, '>');
g_variant_unref (child);
}
break;
case G_VARIANT_CLASS_BOOLEAN:
if (g_variant_get_boolean (value))
g_string_append (string, "true");
else
g_string_append (string, "false");
break;
case G_VARIANT_CLASS_STRING:
{
const gchar *str = g_variant_get_string (value, NULL);
gunichar quote = strchr (str, '\'') ? '"' : '\'';
g_string_append_c (string, quote);
while (*str)
{
gunichar c = g_utf8_get_char (str);
if (c == quote || c == '\\')
g_string_append_c (string, '\\');
if (g_unichar_isprint (c))
g_string_append_unichar (string, c);
else
{
g_string_append_c (string, '\\');
if (c < 0x10000)
switch (c)
{
case '\a':
g_string_append_c (string, 'a');
break;
case '\b':
g_string_append_c (string, 'b');
break;
case '\f':
g_string_append_c (string, 'f');
break;
case '\n':
g_string_append_c (string, 'n');
break;
case '\r':
g_string_append_c (string, 'r');
break;
case '\t':
g_string_append_c (string, 't');
break;
case '\v':
g_string_append_c (string, 'v');
break;
default:
g_string_append_printf (string, "u%04x", c);
break;
}
else
g_string_append_printf (string, "U%08x", c);
}
str = g_utf8_next_char (str);
}
g_string_append_c (string, quote);
}
break;
case G_VARIANT_CLASS_BYTE:
if (type_annotate)
g_string_append (string, "byte ");
g_string_append_printf (string, "0x%02x",
g_variant_get_byte (value));
break;
case G_VARIANT_CLASS_INT16:
if (type_annotate)
g_string_append (string, "int16 ");
g_string_append_printf (string, "%"G_GINT16_FORMAT,
g_variant_get_int16 (value));
break;
case G_VARIANT_CLASS_UINT16:
if (type_annotate)
g_string_append (string, "uint16 ");
g_string_append_printf (string, "%"G_GUINT16_FORMAT,
g_variant_get_uint16 (value));
break;
case G_VARIANT_CLASS_INT32:
/* Never annotate this type because it is the default for numbers
* (and this is a *pretty* printer)
*/
g_string_append_printf (string, "%"G_GINT32_FORMAT,
g_variant_get_int32 (value));
break;
case G_VARIANT_CLASS_HANDLE:
if (type_annotate)
g_string_append (string, "handle ");
g_string_append_printf (string, "%"G_GINT32_FORMAT,
g_variant_get_handle (value));
break;
case G_VARIANT_CLASS_UINT32:
if (type_annotate)
g_string_append (string, "uint32 ");
g_string_append_printf (string, "%"G_GUINT32_FORMAT,
g_variant_get_uint32 (value));
break;
case G_VARIANT_CLASS_INT64:
if (type_annotate)
g_string_append (string, "int64 ");
g_string_append_printf (string, "%"G_GINT64_FORMAT,
g_variant_get_int64 (value));
break;
case G_VARIANT_CLASS_UINT64:
if (type_annotate)
g_string_append (string, "uint64 ");
g_string_append_printf (string, "%"G_GUINT64_FORMAT,
g_variant_get_uint64 (value));
break;
case G_VARIANT_CLASS_DOUBLE:
{
gchar buffer[100];
gint i;
g_ascii_dtostr (buffer, sizeof buffer, g_variant_get_double (value));
for (i = 0; buffer[i]; i++)
if (buffer[i] == '.' || buffer[i] == 'e' ||
buffer[i] == 'n' || buffer[i] == 'N')
break;
/* if there is no '.' or 'e' in the float then add one */
if (buffer[i] == '\0')
{
buffer[i++] = '.';
buffer[i++] = '0';
buffer[i++] = '\0';
}
g_string_append (string, buffer);
}
break;
case G_VARIANT_CLASS_OBJECT_PATH:
if (type_annotate)
g_string_append (string, "objectpath ");
g_string_append_printf (string, "\'%s\'",
g_variant_get_string (value, NULL));
break;
case G_VARIANT_CLASS_SIGNATURE:
if (type_annotate)
g_string_append (string, "signature ");
g_string_append_printf (string, "\'%s\'",
g_variant_get_string (value, NULL));
break;
default:
g_assert_not_reached ();
}
return string;
}
/**
* g_variant_print:
* @value: a #GVariant
* @type_annotate: %TRUE if type information should be included in
* the output
*
* Pretty-prints @value in the format understood by g_variant_parse().
*
* The format is described [here][gvariant-text].
*
* If @type_annotate is %TRUE, then type information is included in
* the output.
*
* Returns: (transfer full): a newly-allocated string holding the result.
*
* Since: 2.24
*/
gchar *
g_variant_print (GVariant *value,
gboolean type_annotate)
{
return g_string_free (g_variant_print_string (value, NULL, type_annotate),
FALSE);
}
/* Hash, Equal, Compare {{{1 */
/**
* g_variant_hash:
* @value: (type GVariant): a basic #GVariant value as a #gconstpointer
*
* Generates a hash value for a #GVariant instance.
*
* The output of this function is guaranteed to be the same for a given
* value only per-process. It may change between different processor
* architectures or even different versions of GLib. Do not use this
* function as a basis for building protocols or file formats.
*
* The type of @value is #gconstpointer only to allow use of this
* function with #GHashTable. @value must be a #GVariant.
*
* Returns: a hash value corresponding to @value
*
* Since: 2.24
**/
guint
g_variant_hash (gconstpointer value_)
{
GVariant *value = (GVariant *) value_;
switch (g_variant_classify (value))
{
case G_VARIANT_CLASS_STRING:
case G_VARIANT_CLASS_OBJECT_PATH:
case G_VARIANT_CLASS_SIGNATURE:
return g_str_hash (g_variant_get_string (value, NULL));
case G_VARIANT_CLASS_BOOLEAN:
/* this is a very odd thing to hash... */
return g_variant_get_boolean (value);
case G_VARIANT_CLASS_BYTE:
return g_variant_get_byte (value);
case G_VARIANT_CLASS_INT16:
case G_VARIANT_CLASS_UINT16:
{
const guint16 *ptr;
ptr = g_variant_get_data (value);
if (ptr)
return *ptr;
else
return 0;
}
case G_VARIANT_CLASS_INT32:
case G_VARIANT_CLASS_UINT32:
case G_VARIANT_CLASS_HANDLE:
{
const guint *ptr;
ptr = g_variant_get_data (value);
if (ptr)
return *ptr;
else
return 0;
}
case G_VARIANT_CLASS_INT64:
case G_VARIANT_CLASS_UINT64:
case G_VARIANT_CLASS_DOUBLE:
/* need a separate case for these guys because otherwise
* performance could be quite bad on big endian systems
*/
{
const guint *ptr;
ptr = g_variant_get_data (value);
if (ptr)
return ptr[0] + ptr[1];
else
return 0;
}
default:
g_return_val_if_fail (!g_variant_is_container (value), 0);
g_assert_not_reached ();
}
}
/**
* g_variant_equal:
* @one: (type GVariant): a #GVariant instance
* @two: (type GVariant): a #GVariant instance
*
* Checks if @one and @two have the same type and value.
*
* The types of @one and @two are #gconstpointer only to allow use of
* this function with #GHashTable. They must each be a #GVariant.
*
* Returns: %TRUE if @one and @two are equal
*
* Since: 2.24
**/
gboolean
g_variant_equal (gconstpointer one,
gconstpointer two)
{
gboolean equal;
g_return_val_if_fail (one != NULL && two != NULL, FALSE);
if (g_variant_get_type_info ((GVariant *) one) !=
g_variant_get_type_info ((GVariant *) two))
return FALSE;
/* if both values are trusted to be in their canonical serialised form
* then a simple memcmp() of their serialised data will answer the
* question.
*
* if not, then this might generate a false negative (since it is
* possible for two different byte sequences to represent the same
* value). for now we solve this by pretty-printing both values and
* comparing the result.
*/
if (g_variant_is_trusted ((GVariant *) one) &&
g_variant_is_trusted ((GVariant *) two))
{
gconstpointer data_one, data_two;
gsize size_one, size_two;
size_one = g_variant_get_size ((GVariant *) one);
size_two = g_variant_get_size ((GVariant *) two);
if (size_one != size_two)
return FALSE;
data_one = g_variant_get_data ((GVariant *) one);
data_two = g_variant_get_data ((GVariant *) two);
equal = memcmp (data_one, data_two, size_one) == 0;
}
else
{
gchar *strone, *strtwo;
strone = g_variant_print ((GVariant *) one, FALSE);
strtwo = g_variant_print ((GVariant *) two, FALSE);
equal = strcmp (strone, strtwo) == 0;
g_free (strone);
g_free (strtwo);
}
return equal;
}
/**
* g_variant_compare:
* @one: (type GVariant): a basic-typed #GVariant instance
* @two: (type GVariant): a #GVariant instance of the same type
*
* Compares @one and @two.
*
* The types of @one and @two are #gconstpointer only to allow use of
* this function with #GTree, #GPtrArray, etc. They must each be a
* #GVariant.
*
* Comparison is only defined for basic types (ie: booleans, numbers,
* strings). For booleans, %FALSE is less than %TRUE. Numbers are
* ordered in the usual way. Strings are in ASCII lexographical order.
*
* It is a programmer error to attempt to compare container values or
* two values that have types that are not exactly equal. For example,
* you cannot compare a 32-bit signed integer with a 32-bit unsigned
* integer. Also note that this function is not particularly
* well-behaved when it comes to comparison of doubles; in particular,
* the handling of incomparable values (ie: NaN) is undefined.
*
* If you only require an equality comparison, g_variant_equal() is more
* general.
*
* Returns: negative value if a < b;
* zero if a = b;
* positive value if a > b.
*
* Since: 2.26
**/
gint
g_variant_compare (gconstpointer one,
gconstpointer two)
{
GVariant *a = (GVariant *) one;
GVariant *b = (GVariant *) two;
g_return_val_if_fail (g_variant_classify (a) == g_variant_classify (b), 0);
switch (g_variant_classify (a))
{
case G_VARIANT_CLASS_BOOLEAN:
return g_variant_get_boolean (a) -
g_variant_get_boolean (b);
case G_VARIANT_CLASS_BYTE:
return ((gint) g_variant_get_byte (a)) -
((gint) g_variant_get_byte (b));
case G_VARIANT_CLASS_INT16:
return ((gint) g_variant_get_int16 (a)) -
((gint) g_variant_get_int16 (b));
case G_VARIANT_CLASS_UINT16:
return ((gint) g_variant_get_uint16 (a)) -
((gint) g_variant_get_uint16 (b));
case G_VARIANT_CLASS_INT32:
{
gint32 a_val = g_variant_get_int32 (a);
gint32 b_val = g_variant_get_int32 (b);
return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
}
case G_VARIANT_CLASS_UINT32:
{
guint32 a_val = g_variant_get_uint32 (a);
guint32 b_val = g_variant_get_uint32 (b);
return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
}
case G_VARIANT_CLASS_INT64:
{
gint64 a_val = g_variant_get_int64 (a);
gint64 b_val = g_variant_get_int64 (b);
return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
}
case G_VARIANT_CLASS_UINT64:
{
guint64 a_val = g_variant_get_uint64 (a);
guint64 b_val = g_variant_get_uint64 (b);
return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
}
case G_VARIANT_CLASS_DOUBLE:
{
gdouble a_val = g_variant_get_double (a);
gdouble b_val = g_variant_get_double (b);
return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
}
case G_VARIANT_CLASS_STRING:
case G_VARIANT_CLASS_OBJECT_PATH:
case G_VARIANT_CLASS_SIGNATURE:
return strcmp (g_variant_get_string (a, NULL),
g_variant_get_string (b, NULL));
default:
g_return_val_if_fail (!g_variant_is_container (a), 0);
g_assert_not_reached ();
}
}
/* GVariantIter {{{1 */
/**
* GVariantIter: (skip)
*
* #GVariantIter is an opaque data structure and can only be accessed
* using the following functions.
**/
struct stack_iter
{
GVariant *value;
gssize n, i;
const gchar *loop_format;
gsize padding[3];
gsize magic;
};
G_STATIC_ASSERT (sizeof (struct stack_iter) <= sizeof (GVariantIter));
struct heap_iter
{
struct stack_iter iter;
GVariant *value_ref;
gsize magic;
};
#define GVSI(i) ((struct stack_iter *) (i))
#define GVHI(i) ((struct heap_iter *) (i))
#define GVSI_MAGIC ((gsize) 3579507750u)
#define GVHI_MAGIC ((gsize) 1450270775u)
#define is_valid_iter(i) (i != NULL && \
GVSI(i)->magic == GVSI_MAGIC)
#define is_valid_heap_iter(i) (is_valid_iter(i) && \
GVHI(i)->magic == GVHI_MAGIC)
/**
* g_variant_iter_new:
* @value: a container #GVariant
*
* Creates a heap-allocated #GVariantIter for iterating over the items
* in @value.
*
* Use g_variant_iter_free() to free the return value when you no longer
* need it.
*
* A reference is taken to @value and will be released only when
* g_variant_iter_free() is called.
*
* Returns: (transfer full): a new heap-allocated #GVariantIter
*
* Since: 2.24
**/
GVariantIter *
g_variant_iter_new (GVariant *value)
{
GVariantIter *iter;
iter = (GVariantIter *) g_slice_new (struct heap_iter);
GVHI(iter)->value_ref = g_variant_ref (value);
GVHI(iter)->magic = GVHI_MAGIC;
g_variant_iter_init (iter, value);
return iter;
}
/**
* g_variant_iter_init: (skip)
* @iter: a pointer to a #GVariantIter
* @value: a container #GVariant
*
* Initialises (without allocating) a #GVariantIter. @iter may be
* completely uninitialised prior to this call; its old value is
* ignored.
*
* The iterator remains valid for as long as @value exists, and need not
* be freed in any way.
*
* Returns: the number of items in @value
*
* Since: 2.24
**/
gsize
g_variant_iter_init (GVariantIter *iter,
GVariant *value)
{
GVSI(iter)->magic = GVSI_MAGIC;
GVSI(iter)->value = value;
GVSI(iter)->n = g_variant_n_children (value);
GVSI(iter)->i = -1;
GVSI(iter)->loop_format = NULL;
return GVSI(iter)->n;
}
/**
* g_variant_iter_copy:
* @iter: a #GVariantIter
*
* Creates a new heap-allocated #GVariantIter to iterate over the
* container that was being iterated over by @iter. Iteration begins on
* the new iterator from the current position of the old iterator but
* the two copies are independent past that point.
*
* Use g_variant_iter_free() to free the return value when you no longer
* need it.
*
* A reference is taken to the container that @iter is iterating over
* and will be releated only when g_variant_iter_free() is called.
*
* Returns: (transfer full): a new heap-allocated #GVariantIter
*
* Since: 2.24
**/
GVariantIter *
g_variant_iter_copy (GVariantIter *iter)
{
GVariantIter *copy;
g_return_val_if_fail (is_valid_iter (iter), 0);
copy = g_variant_iter_new (GVSI(iter)->value);
GVSI(copy)->i = GVSI(iter)->i;
return copy;
}
/**
* g_variant_iter_n_children:
* @iter: a #GVariantIter
*
* Queries the number of child items in the container that we are
* iterating over. This is the total number of items -- not the number
* of items remaining.
*
* This function might be useful for preallocation of arrays.
*
* Returns: the number of children in the container
*
* Since: 2.24
**/
gsize
g_variant_iter_n_children (GVariantIter *iter)
{
g_return_val_if_fail (is_valid_iter (iter), 0);
return GVSI(iter)->n;
}
/**
* g_variant_iter_free:
* @iter: (transfer full): a heap-allocated #GVariantIter
*
* Frees a heap-allocated #GVariantIter. Only call this function on
* iterators that were returned by g_variant_iter_new() or
* g_variant_iter_copy().
*
* Since: 2.24
**/
void
g_variant_iter_free (GVariantIter *iter)
{
g_return_if_fail (is_valid_heap_iter (iter));
g_variant_unref (GVHI(iter)->value_ref);
GVHI(iter)->magic = 0;
g_slice_free (struct heap_iter, GVHI(iter));
}
/**
* g_variant_iter_next_value:
* @iter: a #GVariantIter
*
* Gets the next item in the container. If no more items remain then
* %NULL is returned.
*
* Use g_variant_unref() to drop your reference on the return value when
* you no longer need it.
*
* Here is an example for iterating with g_variant_iter_next_value():
* |[<!-- language="C" -->
* // recursively iterate a container
* void
* iterate_container_recursive (GVariant *container)
* {
* GVariantIter iter;
* GVariant *child;
*
* g_variant_iter_init (&iter, container);
* while ((child = g_variant_iter_next_value (&iter)))
* {
* g_print ("type '%s'\n", g_variant_get_type_string (child));
*
* if (g_variant_is_container (child))
* iterate_container_recursive (child);
*
* g_variant_unref (child);
* }
* }
* ]|
*
* Returns: (nullable) (transfer full): a #GVariant, or %NULL
*
* Since: 2.24
**/
GVariant *
g_variant_iter_next_value (GVariantIter *iter)
{
g_return_val_if_fail (is_valid_iter (iter), FALSE);
if G_UNLIKELY (GVSI(iter)->i >= GVSI(iter)->n)
{
g_critical ("g_variant_iter_next_value: must not be called again "
"after NULL has already been returned.");
return NULL;
}
GVSI(iter)->i++;
if (GVSI(iter)->i < GVSI(iter)->n)
return g_variant_get_child_value (GVSI(iter)->value, GVSI(iter)->i);
return NULL;
}
/* GVariantBuilder {{{1 */
/**
* GVariantBuilder:
*
* A utility type for constructing container-type #GVariant instances.
*
* This is an opaque structure and may only be accessed using the
* following functions.
*
* #GVariantBuilder is not threadsafe in any way. Do not attempt to
* access it from more than one thread.
**/
struct stack_builder
{
GVariantBuilder *parent;
GVariantType *type;
/* type constraint explicitly specified by 'type'.
* for tuple types, this moves along as we add more items.
*/
const GVariantType *expected_type;
/* type constraint implied by previous array item.
*/
const GVariantType *prev_item_type;
/* constraints on the number of children. max = -1 for unlimited. */
gsize min_items;
gsize max_items;
/* dynamically-growing pointer array */
GVariant **children;
gsize allocated_children;
gsize offset;
/* set to '1' if all items in the container will have the same type
* (ie: maybe, array, variant) '0' if not (ie: tuple, dict entry)
*/
guint uniform_item_types : 1;
/* set to '1' initially and changed to '0' if an untrusted value is
* added
*/
guint trusted : 1;
gsize magic;
};
G_STATIC_ASSERT (sizeof (struct stack_builder) <= sizeof (GVariantBuilder));
struct heap_builder
{
GVariantBuilder builder;
gsize magic;
gint ref_count;
};
#define GVSB(b) ((struct stack_builder *) (b))
#define GVHB(b) ((struct heap_builder *) (b))
#define GVSB_MAGIC ((gsize) 1033660112u)
#define GVSB_MAGIC_PARTIAL ((gsize) 2942751021u)
#define GVHB_MAGIC ((gsize) 3087242682u)
#define is_valid_builder(b) (b != NULL && \
GVSB(b)->magic == GVSB_MAGIC)
#define is_valid_heap_builder(b) (GVHB(b)->magic == GVHB_MAGIC)
/* Just to make sure that by adding a union to GVariantBuilder, we
* didn't accidentally change ABI. */
G_STATIC_ASSERT (sizeof (GVariantBuilder) == sizeof (gsize[16]));
static gboolean
ensure_valid_builder (GVariantBuilder *builder)
{
if (is_valid_builder (builder))
return TRUE;
if (builder->u.s.partial_magic == GVSB_MAGIC_PARTIAL)
{
static GVariantBuilder cleared_builder;
/* Make sure that only first two fields were set and the rest is
* zeroed to avoid messing up the builder that had parent
* address equal to GVSB_MAGIC_PARTIAL. */
if (memcmp (cleared_builder.u.s.y, builder->u.s.y, sizeof cleared_builder.u.s.y))
return FALSE;
g_variant_builder_init (builder, builder->u.s.type);
}
return is_valid_builder (builder);
}
/**
* g_variant_builder_new:
* @type: a container type
*
* Allocates and initialises a new #GVariantBuilder.
*
* You should call g_variant_builder_unref() on the return value when it
* is no longer needed. The memory will not be automatically freed by
* any other call.
*
* In most cases it is easier to place a #GVariantBuilder directly on
* the stack of the calling function and initialise it with
* g_variant_builder_init().
*
* Returns: (transfer full): a #GVariantBuilder
*
* Since: 2.24
**/
GVariantBuilder *
g_variant_builder_new (const GVariantType *type)
{
GVariantBuilder *builder;
builder = (GVariantBuilder *) g_slice_new (struct heap_builder);
g_variant_builder_init (builder, type);
GVHB(builder)->magic = GVHB_MAGIC;
GVHB(builder)->ref_count = 1;
return builder;
}
/**
* g_variant_builder_unref:
* @builder: (transfer full): a #GVariantBuilder allocated by g_variant_builder_new()
*
* Decreases the reference count on @builder.
*
* In the event that there are no more references, releases all memory
* associated with the #GVariantBuilder.
*
* Don't call this on stack-allocated #GVariantBuilder instances or bad
* things will happen.
*
* Since: 2.24
**/
void
g_variant_builder_unref (GVariantBuilder *builder)
{
g_return_if_fail (is_valid_heap_builder (builder));
if (--GVHB(builder)->ref_count)
return;
g_variant_builder_clear (builder);
GVHB(builder)->magic = 0;
g_slice_free (struct heap_builder, GVHB(builder));
}
/**
* g_variant_builder_ref:
* @builder: a #GVariantBuilder allocated by g_variant_builder_new()
*
* Increases the reference count on @builder.
*
* Don't call this on stack-allocated #GVariantBuilder instances or bad
* things will happen.
*
* Returns: (transfer full): a new reference to @builder
*
* Since: 2.24
**/
GVariantBuilder *
g_variant_builder_ref (GVariantBuilder *builder)
{
g_return_val_if_fail (is_valid_heap_builder (builder), NULL);
GVHB(builder)->ref_count++;
return builder;
}
/**
* g_variant_builder_clear: (skip)
* @builder: a #GVariantBuilder
*
* Releases all memory associated with a #GVariantBuilder without
* freeing the #GVariantBuilder structure itself.
*
* It typically only makes sense to do this on a stack-allocated
* #GVariantBuilder if you want to abort building the value part-way
* through. This function need not be called if you call
* g_variant_builder_end() and it also doesn't need to be called on
* builders allocated with g_variant_builder_new() (see
* g_variant_builder_unref() for that).
*
* This function leaves the #GVariantBuilder structure set to all-zeros.
* It is valid to call this function on either an initialised
* #GVariantBuilder or one that is set to all-zeros but it is not valid
* to call this function on uninitialised memory.
*
* Since: 2.24
**/
void
g_variant_builder_clear (GVariantBuilder *builder)
{
gsize i;
if (GVSB(builder)->magic == 0)
/* all-zeros or partial case */
return;
g_return_if_fail (ensure_valid_builder (builder));
g_variant_type_free (GVSB(builder)->type);
for (i = 0; i < GVSB(builder)->offset; i++)
g_variant_unref (GVSB(builder)->children[i]);
g_free (GVSB(builder)->children);
if (GVSB(builder)->parent)
{
g_variant_builder_clear (GVSB(builder)->parent);
g_slice_free (GVariantBuilder, GVSB(builder)->parent);
}
memset (builder, 0, sizeof (GVariantBuilder));
}
/**
* g_variant_builder_init: (skip)
* @builder: a #GVariantBuilder
* @type: a container type
*
* Initialises a #GVariantBuilder structure.
*
* @type must be non-%NULL. It specifies the type of container to
* construct. It can be an indefinite type such as
* %G_VARIANT_TYPE_ARRAY or a definite type such as "as" or "(ii)".
* Maybe, array, tuple, dictionary entry and variant-typed values may be
* constructed.
*
* After the builder is initialised, values are added using
* g_variant_builder_add_value() or g_variant_builder_add().
*
* After all the child values are added, g_variant_builder_end() frees
* the memory associated with the builder and returns the #GVariant that
* was created.
*
* This function completely ignores the previous contents of @builder.
* On one hand this means that it is valid to pass in completely
* uninitialised memory. On the other hand, this means that if you are
* initialising over top of an existing #GVariantBuilder you need to
* first call g_variant_builder_clear() in order to avoid leaking
* memory.
*
* You must not call g_variant_builder_ref() or
* g_variant_builder_unref() on a #GVariantBuilder that was initialised
* with this function. If you ever pass a reference to a
* #GVariantBuilder outside of the control of your own code then you
* should assume that the person receiving that reference may try to use
* reference counting; you should use g_variant_builder_new() instead of
* this function.
*
* Since: 2.24
**/
void
g_variant_builder_init (GVariantBuilder *builder,
const GVariantType *type)
{
g_return_if_fail (type != NULL);
g_return_if_fail (g_variant_type_is_container (type));
memset (builder, 0, sizeof (GVariantBuilder));
GVSB(builder)->type = g_variant_type_copy (type);
GVSB(builder)->magic = GVSB_MAGIC;
GVSB(builder)->trusted = TRUE;
switch (*(const gchar *) type)
{
case G_VARIANT_CLASS_VARIANT:
GVSB(builder)->uniform_item_types = TRUE;
GVSB(builder)->allocated_children = 1;
GVSB(builder)->expected_type = NULL;
GVSB(builder)->min_items = 1;
GVSB(builder)->max_items = 1;
break;
case G_VARIANT_CLASS_ARRAY:
GVSB(builder)->uniform_item_types = TRUE;
GVSB(builder)->allocated_children = 8;
GVSB(builder)->expected_type =
g_variant_type_element (GVSB(builder)->type);
GVSB(builder)->min_items = 0;
GVSB(builder)->max_items = -1;
break;
case G_VARIANT_CLASS_MAYBE:
GVSB(builder)->uniform_item_types = TRUE;
GVSB(builder)->allocated_children = 1;
GVSB(builder)->expected_type =
g_variant_type_element (GVSB(builder)->type);
GVSB(builder)->min_items = 0;
GVSB(builder)->max_items = 1;
break;
case G_VARIANT_CLASS_DICT_ENTRY:
GVSB(builder)->uniform_item_types = FALSE;
GVSB(builder)->allocated_children = 2;
GVSB(builder)->expected_type =
g_variant_type_key (GVSB(builder)->type);
GVSB(builder)->min_items = 2;
GVSB(builder)->max_items = 2;
break;
case 'r': /* G_VARIANT_TYPE_TUPLE was given */
GVSB(builder)->uniform_item_types = FALSE;
GVSB(builder)->allocated_children = 8;
GVSB(builder)->expected_type = NULL;
GVSB(builder)->min_items = 0;
GVSB(builder)->max_items = -1;
break;
case G_VARIANT_CLASS_TUPLE: /* a definite tuple type was given */
GVSB(builder)->allocated_children = g_variant_type_n_items (type);
GVSB(builder)->expected_type =
g_variant_type_first (GVSB(builder)->type);
GVSB(builder)->min_items = GVSB(builder)->allocated_children;
GVSB(builder)->max_items = GVSB(builder)->allocated_children;
GVSB(builder)->uniform_item_types = FALSE;
break;
default:
g_assert_not_reached ();
}
GVSB(builder)->children = g_new (GVariant *,
GVSB(builder)->allocated_children);
}
static void
g_variant_builder_make_room (struct stack_builder *builder)
{
if (builder->offset == builder->allocated_children)
{
builder->allocated_children *= 2;
builder->children = g_renew (GVariant *, builder->children,
builder->allocated_children);
}
}
/**
* g_variant_builder_add_value:
* @builder: a #GVariantBuilder
* @value: a #GVariant
*
* Adds @value to @builder.
*
* It is an error to call this function in any way that would create an
* inconsistent value to be constructed. Some examples of this are
* putting different types of items into an array, putting the wrong
* types or number of items in a tuple, putting more than one value into
* a variant, etc.
*
* If @value is a floating reference (see g_variant_ref_sink()),
* the @builder instance takes ownership of @value.
*
* Since: 2.24
**/
void
g_variant_builder_add_value (GVariantBuilder *builder,
GVariant *value)
{
g_return_if_fail (ensure_valid_builder (builder));
g_return_if_fail (GVSB(builder)->offset < GVSB(builder)->max_items);
g_return_if_fail (!GVSB(builder)->expected_type ||
g_variant_is_of_type (value,
GVSB(builder)->expected_type));
g_return_if_fail (!GVSB(builder)->prev_item_type ||
g_variant_is_of_type (value,
GVSB(builder)->prev_item_type));
GVSB(builder)->trusted &= g_variant_is_trusted (value);
if (!GVSB(builder)->uniform_item_types)
{
/* advance our expected type pointers */
if (GVSB(builder)->expected_type)
GVSB(builder)->expected_type =
g_variant_type_next (GVSB(builder)->expected_type);
if (GVSB(builder)->prev_item_type)
GVSB(builder)->prev_item_type =
g_variant_type_next (GVSB(builder)->prev_item_type);
}
else
GVSB(builder)->prev_item_type = g_variant_get_type (value);
g_variant_builder_make_room (GVSB(builder));
GVSB(builder)->children[GVSB(builder)->offset++] =
g_variant_ref_sink (value);
}
/**
* g_variant_builder_open:
* @builder: a #GVariantBuilder
* @type: the #GVariantType of the container
*
* Opens a subcontainer inside the given @builder. When done adding
* items to the subcontainer, g_variant_builder_close() must be called. @type
* is the type of the container: so to build a tuple of several values, @type
* must include the tuple itself.
*
* It is an error to call this function in any way that would cause an
* inconsistent value to be constructed (ie: adding too many values or
* a value of an incorrect type).
*
* Example of building a nested variant:
* |[<!-- language="C" -->
* GVariantBuilder builder;
* guint32 some_number = get_number ();
* g_autoptr (GHashTable) some_dict = get_dict ();
* GHashTableIter iter;
* const gchar *key;
* const GVariant *value;
* g_autoptr (GVariant) output = NULL;
*
* g_variant_builder_init (&builder, G_VARIANT_TYPE ("(ua{sv})"));
* g_variant_builder_add (&builder, "u", some_number);
* g_variant_builder_open (&builder, G_VARIANT_TYPE ("a{sv}"));
*
* g_hash_table_iter_init (&iter, some_dict);
* while (g_hash_table_iter_next (&iter, (gpointer *) &key, (gpointer *) &value))
* {
* g_variant_builder_open (&builder, G_VARIANT_TYPE ("{sv}"));
* g_variant_builder_add (&builder, "s", key);
* g_variant_builder_add (&builder, "v", value);
* g_variant_builder_close (&builder);
* }
*
* g_variant_builder_close (&builder);
*
* output = g_variant_builder_end (&builder);
* ]|
*
* Since: 2.24
**/
void
g_variant_builder_open (GVariantBuilder *builder,
const GVariantType *type)
{
GVariantBuilder *parent;
g_return_if_fail (ensure_valid_builder (builder));
g_return_if_fail (GVSB(builder)->offset < GVSB(builder)->max_items);
g_return_if_fail (!GVSB(builder)->expected_type ||
g_variant_type_is_subtype_of (type,
GVSB(builder)->expected_type));
g_return_if_fail (!GVSB(builder)->prev_item_type ||
g_variant_type_is_subtype_of (GVSB(builder)->prev_item_type,
type));
parent = g_slice_dup (GVariantBuilder, builder);
g_variant_builder_init (builder, type);
GVSB(builder)->parent = parent;
/* push the prev_item_type down into the subcontainer */
if (GVSB(parent)->prev_item_type)
{
if (!GVSB(builder)->uniform_item_types)
/* tuples and dict entries */
GVSB(builder)->prev_item_type =
g_variant_type_first (GVSB(parent)->prev_item_type);
else if (!g_variant_type_is_variant (GVSB(builder)->type))
/* maybes and arrays */
GVSB(builder)->prev_item_type =
g_variant_type_element (GVSB(parent)->prev_item_type);
}
}
/**
* g_variant_builder_close:
* @builder: a #GVariantBuilder
*
* Closes the subcontainer inside the given @builder that was opened by
* the most recent call to g_variant_builder_open().
*
* It is an error to call this function in any way that would create an
* inconsistent value to be constructed (ie: too few values added to the
* subcontainer).
*
* Since: 2.24
**/
void
g_variant_builder_close (GVariantBuilder *builder)
{
GVariantBuilder *parent;
g_return_if_fail (ensure_valid_builder (builder));
g_return_if_fail (GVSB(builder)->parent != NULL);
parent = GVSB(builder)->parent;
GVSB(builder)->parent = NULL;
g_variant_builder_add_value (parent, g_variant_builder_end (builder));
*builder = *parent;
g_slice_free (GVariantBuilder, parent);
}
/*< private >
* g_variant_make_maybe_type:
* @element: a #GVariant
*
* Return the type of a maybe containing @element.
*/
static GVariantType *
g_variant_make_maybe_type (GVariant *element)
{
return g_variant_type_new_maybe (g_variant_get_type (element));
}
/*< private >
* g_variant_make_array_type:
* @element: a #GVariant
*
* Return the type of an array containing @element.
*/
static GVariantType *
g_variant_make_array_type (GVariant *element)
{
return g_variant_type_new_array (g_variant_get_type (element));
}
/**
* g_variant_builder_end:
* @builder: a #GVariantBuilder
*
* Ends the builder process and returns the constructed value.
*
* It is not permissible to use @builder in any way after this call
* except for reference counting operations (in the case of a
* heap-allocated #GVariantBuilder) or by reinitialising it with
* g_variant_builder_init() (in the case of stack-allocated). This
* means that for the stack-allocated builders there is no need to
* call g_variant_builder_clear() after the call to
* g_variant_builder_end().
*
* It is an error to call this function in any way that would create an
* inconsistent value to be constructed (ie: insufficient number of
* items added to a container with a specific number of children
* required). It is also an error to call this function if the builder
* was created with an indefinite array or maybe type and no children
* have been added; in this case it is impossible to infer the type of
* the empty array.
*
* Returns: (transfer none): a new, floating, #GVariant
*
* Since: 2.24
**/
GVariant *
g_variant_builder_end (GVariantBuilder *builder)
{
GVariantType *my_type;
GVariant *value;
g_return_val_if_fail (ensure_valid_builder (builder), NULL);
g_return_val_if_fail (GVSB(builder)->offset >= GVSB(builder)->min_items,
NULL);
g_return_val_if_fail (!GVSB(builder)->uniform_item_types ||
GVSB(builder)->prev_item_type != NULL ||
g_variant_type_is_definite (GVSB(builder)->type),
NULL);
if (g_variant_type_is_definite (GVSB(builder)->type))
my_type = g_variant_type_copy (GVSB(builder)->type);
else if (g_variant_type_is_maybe (GVSB(builder)->type))
my_type = g_variant_make_maybe_type (GVSB(builder)->children[0]);
else if (g_variant_type_is_array (GVSB(builder)->type))
my_type = g_variant_make_array_type (GVSB(builder)->children[0]);
else if (g_variant_type_is_tuple (GVSB(builder)->type))
my_type = g_variant_make_tuple_type (GVSB(builder)->children,
GVSB(builder)->offset);
else if (g_variant_type_is_dict_entry (GVSB(builder)->type))
my_type = g_variant_make_dict_entry_type (GVSB(builder)->children[0],
GVSB(builder)->children[1]);
else
g_assert_not_reached ();
value = g_variant_new_from_children (my_type,
g_renew (GVariant *,
GVSB(builder)->children,
GVSB(builder)->offset),
GVSB(builder)->offset,
GVSB(builder)->trusted);
GVSB(builder)->children = NULL;
GVSB(builder)->offset = 0;
g_variant_builder_clear (builder);
g_variant_type_free (my_type);
return value;
}
/* GVariantDict {{{1 */
/**
* GVariantDict:
*
* #GVariantDict is a mutable interface to #GVariant dictionaries.
*
* It can be used for doing a sequence of dictionary lookups in an
* efficient way on an existing #GVariant dictionary or it can be used
* to construct new dictionaries with a hashtable-like interface. It
* can also be used for taking existing dictionaries and modifying them
* in order to create new ones.
*
* #GVariantDict can only be used with %G_VARIANT_TYPE_VARDICT
* dictionaries.
*
* It is possible to use #GVariantDict allocated on the stack or on the
* heap. When using a stack-allocated #GVariantDict, you begin with a
* call to g_variant_dict_init() and free the resources with a call to
* g_variant_dict_clear().
*
* Heap-allocated #GVariantDict follows normal refcounting rules: you
* allocate it with g_variant_dict_new() and use g_variant_dict_ref()
* and g_variant_dict_unref().
*
* g_variant_dict_end() is used to convert the #GVariantDict back into a
* dictionary-type #GVariant. When used with stack-allocated instances,
* this also implicitly frees all associated memory, but for
* heap-allocated instances, you must still call g_variant_dict_unref()
* afterwards.
*
* You will typically want to use a heap-allocated #GVariantDict when
* you expose it as part of an API. For most other uses, the
* stack-allocated form will be more convenient.
*
* Consider the following two examples that do the same thing in each
* style: take an existing dictionary and look up the "count" uint32
* key, adding 1 to it if it is found, or returning an error if the
* key is not found. Each returns the new dictionary as a floating
* #GVariant.
*
* ## Using a stack-allocated GVariantDict
*
* |[<!-- language="C" -->
* GVariant *
* add_to_count (GVariant *orig,
* GError **error)
* {
* GVariantDict dict;
* guint32 count;
*
* g_variant_dict_init (&dict, orig);
* if (!g_variant_dict_lookup (&dict, "count", "u", &count))
* {
* g_set_error (...);
* g_variant_dict_clear (&dict);
* return NULL;
* }
*
* g_variant_dict_insert (&dict, "count", "u", count + 1);
*
* return g_variant_dict_end (&dict);
* }
* ]|
*
* ## Using heap-allocated GVariantDict
*
* |[<!-- language="C" -->
* GVariant *
* add_to_count (GVariant *orig,
* GError **error)
* {
* GVariantDict *dict;
* GVariant *result;
* guint32 count;
*
* dict = g_variant_dict_new (orig);
*
* if (g_variant_dict_lookup (dict, "count", "u", &count))
* {
* g_variant_dict_insert (dict, "count", "u", count + 1);
* result = g_variant_dict_end (dict);
* }
* else
* {
* g_set_error (...);
* result = NULL;
* }
*
* g_variant_dict_unref (dict);
*
* return result;
* }
* ]|
*
* Since: 2.40
**/
struct stack_dict
{
GHashTable *values;
gsize magic;
};
G_STATIC_ASSERT (sizeof (struct stack_dict) <= sizeof (GVariantDict));
struct heap_dict
{
struct stack_dict dict;
gint ref_count;
gsize magic;
};
#define GVSD(d) ((struct stack_dict *) (d))
#define GVHD(d) ((struct heap_dict *) (d))
#define GVSD_MAGIC ((gsize) 2579507750u)
#define GVSD_MAGIC_PARTIAL ((gsize) 3488698669u)
#define GVHD_MAGIC ((gsize) 2450270775u)
#define is_valid_dict(d) (d != NULL && \
GVSD(d)->magic == GVSD_MAGIC)
#define is_valid_heap_dict(d) (GVHD(d)->magic == GVHD_MAGIC)
/* Just to make sure that by adding a union to GVariantDict, we didn't
* accidentally change ABI. */
G_STATIC_ASSERT (sizeof (GVariantDict) == sizeof (gsize[16]));
static gboolean
ensure_valid_dict (GVariantDict *dict)
{
if (is_valid_dict (dict))
return TRUE;
if (dict->u.s.partial_magic == GVSD_MAGIC_PARTIAL)
{
static GVariantDict cleared_dict;
/* Make sure that only first two fields were set and the rest is
* zeroed to avoid messing up the builder that had parent
* address equal to GVSB_MAGIC_PARTIAL. */
if (memcmp (cleared_dict.u.s.y, dict->u.s.y, sizeof cleared_dict.u.s.y))
return FALSE;
g_variant_dict_init (dict, dict->u.s.asv);
}
return is_valid_dict (dict);
}
/**
* g_variant_dict_new:
* @from_asv: (nullable): the #GVariant with which to initialise the
* dictionary
*
* Allocates and initialises a new #GVariantDict.
*
* You should call g_variant_dict_unref() on the return value when it
* is no longer needed. The memory will not be automatically freed by
* any other call.
*
* In some cases it may be easier to place a #GVariantDict directly on
* the stack of the calling function and initialise it with
* g_variant_dict_init(). This is particularly useful when you are
* using #GVariantDict to construct a #GVariant.
*
* Returns: (transfer full): a #GVariantDict
*
* Since: 2.40
**/
GVariantDict *
g_variant_dict_new (GVariant *from_asv)
{
GVariantDict *dict;
dict = g_slice_alloc (sizeof (struct heap_dict));
g_variant_dict_init (dict, from_asv);
GVHD(dict)->magic = GVHD_MAGIC;
GVHD(dict)->ref_count = 1;
return dict;
}
/**
* g_variant_dict_init: (skip)
* @dict: a #GVariantDict
* @from_asv: (nullable): the initial value for @dict
*
* Initialises a #GVariantDict structure.
*
* If @from_asv is given, it is used to initialise the dictionary.
*
* This function completely ignores the previous contents of @dict. On
* one hand this means that it is valid to pass in completely
* uninitialised memory. On the other hand, this means that if you are
* initialising over top of an existing #GVariantDict you need to first
* call g_variant_dict_clear() in order to avoid leaking memory.
*
* You must not call g_variant_dict_ref() or g_variant_dict_unref() on a
* #GVariantDict that was initialised with this function. If you ever
* pass a reference to a #GVariantDict outside of the control of your
* own code then you should assume that the person receiving that
* reference may try to use reference counting; you should use
* g_variant_dict_new() instead of this function.
*
* Since: 2.40
**/
void
g_variant_dict_init (GVariantDict *dict,
GVariant *from_asv)
{
GVariantIter iter;
gchar *key;
GVariant *value;
GVSD(dict)->values = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify) g_variant_unref);
GVSD(dict)->magic = GVSD_MAGIC;
if (from_asv)
{
g_variant_iter_init (&iter, from_asv);
while (g_variant_iter_next (&iter, "{sv}", &key, &value))
g_hash_table_insert (GVSD(dict)->values, key, value);
}
}
/**
* g_variant_dict_lookup:
* @dict: a #GVariantDict
* @key: the key to lookup in the dictionary
* @format_string: a GVariant format string
* @...: the arguments to unpack the value into
*
* Looks up a value in a #GVariantDict.
*
* This function is a wrapper around g_variant_dict_lookup_value() and
* g_variant_get(). In the case that %NULL would have been returned,
* this function returns %FALSE. Otherwise, it unpacks the returned
* value and returns %TRUE.
*
* @format_string determines the C types that are used for unpacking the
* values and also determines if the values are copied or borrowed, see the
* section on [GVariant format strings][gvariant-format-strings-pointers].
*
* Returns: %TRUE if a value was unpacked
*
* Since: 2.40
**/
gboolean
g_variant_dict_lookup (GVariantDict *dict,
const gchar *key,
const gchar *format_string,
...)
{
GVariant *value;
va_list ap;
g_return_val_if_fail (ensure_valid_dict (dict), FALSE);
g_return_val_if_fail (key != NULL, FALSE);
g_return_val_if_fail (format_string != NULL, FALSE);
value = g_hash_table_lookup (GVSD(dict)->values, key);
if (value == NULL || !g_variant_check_format_string (value, format_string, FALSE))
return FALSE;
va_start (ap, format_string);
g_variant_get_va (value, format_string, NULL, &ap);
va_end (ap);
return TRUE;
}
/**
* g_variant_dict_lookup_value:
* @dict: a #GVariantDict
* @key: the key to lookup in the dictionary
* @expected_type: (nullable): a #GVariantType, or %NULL
*
* Looks up a value in a #GVariantDict.
*
* If @key is not found in @dictionary, %NULL is returned.
*
* The @expected_type string specifies what type of value is expected.
* If the value associated with @key has a different type then %NULL is
* returned.
*
* If the key is found and the value has the correct type, it is
* returned. If @expected_type was specified then any non-%NULL return
* value will have this type.
*
* Returns: (transfer full): the value of the dictionary key, or %NULL
*
* Since: 2.40
**/
GVariant *
g_variant_dict_lookup_value (GVariantDict *dict,
const gchar *key,
const GVariantType *expected_type)
{
GVariant *result;
g_return_val_if_fail (ensure_valid_dict (dict), NULL);
g_return_val_if_fail (key != NULL, NULL);
result = g_hash_table_lookup (GVSD(dict)->values, key);
if (result && (!expected_type || g_variant_is_of_type (result, expected_type)))
return g_variant_ref (result);
return NULL;
}
/**
* g_variant_dict_contains:
* @dict: a #GVariantDict
* @key: the key to lookup in the dictionary
*
* Checks if @key exists in @dict.
*
* Returns: %TRUE if @key is in @dict
*
* Since: 2.40
**/
gboolean
g_variant_dict_contains (GVariantDict *dict,
const gchar *key)
{
g_return_val_if_fail (ensure_valid_dict (dict), FALSE);
g_return_val_if_fail (key != NULL, FALSE);
return g_hash_table_contains (GVSD(dict)->values, key);
}
/**
* g_variant_dict_insert:
* @dict: a #GVariantDict
* @key: the key to insert a value for
* @format_string: a #GVariant varargs format string
* @...: arguments, as per @format_string
*
* Inserts a value into a #GVariantDict.
*
* This call is a convenience wrapper that is exactly equivalent to
* calling g_variant_new() followed by g_variant_dict_insert_value().
*
* Since: 2.40
**/
void
g_variant_dict_insert (GVariantDict *dict,
const gchar *key,
const gchar *format_string,
...)
{
va_list ap;
g_return_if_fail (ensure_valid_dict (dict));
g_return_if_fail (key != NULL);
g_return_if_fail (format_string != NULL);
va_start (ap, format_string);
g_variant_dict_insert_value (dict, key, g_variant_new_va (format_string, NULL, &ap));
va_end (ap);
}
/**
* g_variant_dict_insert_value:
* @dict: a #GVariantDict
* @key: the key to insert a value for
* @value: the value to insert
*
* Inserts (or replaces) a key in a #GVariantDict.
*
* @value is consumed if it is floating.
*
* Since: 2.40
**/
void
g_variant_dict_insert_value (GVariantDict *dict,
const gchar *key,
GVariant *value)
{
g_return_if_fail (ensure_valid_dict (dict));
g_return_if_fail (key != NULL);
g_return_if_fail (value != NULL);
g_hash_table_insert (GVSD(dict)->values, g_strdup (key), g_variant_ref_sink (value));
}
/**
* g_variant_dict_remove:
* @dict: a #GVariantDict
* @key: the key to remove
*
* Removes a key and its associated value from a #GVariantDict.
*
* Returns: %TRUE if the key was found and removed
*
* Since: 2.40
**/
gboolean
g_variant_dict_remove (GVariantDict *dict,
const gchar *key)
{
g_return_val_if_fail (ensure_valid_dict (dict), FALSE);
g_return_val_if_fail (key != NULL, FALSE);
return g_hash_table_remove (GVSD(dict)->values, key);
}
/**
* g_variant_dict_clear:
* @dict: a #GVariantDict
*
* Releases all memory associated with a #GVariantDict without freeing
* the #GVariantDict structure itself.
*
* It typically only makes sense to do this on a stack-allocated
* #GVariantDict if you want to abort building the value part-way
* through. This function need not be called if you call
* g_variant_dict_end() and it also doesn't need to be called on dicts
* allocated with g_variant_dict_new (see g_variant_dict_unref() for
* that).
*
* It is valid to call this function on either an initialised
* #GVariantDict or one that was previously cleared by an earlier call
* to g_variant_dict_clear() but it is not valid to call this function
* on uninitialised memory.
*
* Since: 2.40
**/
void
g_variant_dict_clear (GVariantDict *dict)
{
if (GVSD(dict)->magic == 0)
/* all-zeros case */
return;
g_return_if_fail (ensure_valid_dict (dict));
g_hash_table_unref (GVSD(dict)->values);
GVSD(dict)->values = NULL;
GVSD(dict)->magic = 0;
}
/**
* g_variant_dict_end:
* @dict: a #GVariantDict
*
* Returns the current value of @dict as a #GVariant of type
* %G_VARIANT_TYPE_VARDICT, clearing it in the process.
*
* It is not permissible to use @dict in any way after this call except
* for reference counting operations (in the case of a heap-allocated
* #GVariantDict) or by reinitialising it with g_variant_dict_init() (in
* the case of stack-allocated).
*
* Returns: (transfer none): a new, floating, #GVariant
*
* Since: 2.40
**/
GVariant *
g_variant_dict_end (GVariantDict *dict)
{
GVariantBuilder builder;
GHashTableIter iter;
gpointer key, value;
g_return_val_if_fail (ensure_valid_dict (dict), NULL);
g_variant_builder_init (&builder, G_VARIANT_TYPE_VARDICT);
g_hash_table_iter_init (&iter, GVSD(dict)->values);
while (g_hash_table_iter_next (&iter, &key, &value))
g_variant_builder_add (&builder, "{sv}", (const gchar *) key, (GVariant *) value);
g_variant_dict_clear (dict);
return g_variant_builder_end (&builder);
}
/**
* g_variant_dict_ref:
* @dict: a heap-allocated #GVariantDict
*
* Increases the reference count on @dict.
*
* Don't call this on stack-allocated #GVariantDict instances or bad
* things will happen.
*
* Returns: (transfer full): a new reference to @dict
*
* Since: 2.40
**/
GVariantDict *
g_variant_dict_ref (GVariantDict *dict)
{
g_return_val_if_fail (is_valid_heap_dict (dict), NULL);
GVHD(dict)->ref_count++;
return dict;
}
/**
* g_variant_dict_unref:
* @dict: (transfer full): a heap-allocated #GVariantDict
*
* Decreases the reference count on @dict.
*
* In the event that there are no more references, releases all memory
* associated with the #GVariantDict.
*
* Don't call this on stack-allocated #GVariantDict instances or bad
* things will happen.
*
* Since: 2.40
**/
void
g_variant_dict_unref (GVariantDict *dict)
{
g_return_if_fail (is_valid_heap_dict (dict));
if (--GVHD(dict)->ref_count == 0)
{
g_variant_dict_clear (dict);
g_slice_free (struct heap_dict, (struct heap_dict *) dict);
}
}
/* Format strings {{{1 */
/*< private >
* g_variant_format_string_scan:
* @string: a string that may be prefixed with a format string
* @limit: (nullable) (default NULL): a pointer to the end of @string,
* or %NULL
* @endptr: (nullable) (default NULL): location to store the end pointer,
* or %NULL
*
* Checks the string pointed to by @string for starting with a properly
* formed #GVariant varargs format string. If no valid format string is
* found then %FALSE is returned.
*
* If @string does start with a valid format string then %TRUE is
* returned. If @endptr is non-%NULL then it is updated to point to the
* first character after the format string.
*
* If @limit is non-%NULL then @limit (and any character after it) will
* not be accessed and the effect is otherwise equivalent to if the
* character at @limit were nul.
*
* See the section on [GVariant format strings][gvariant-format-strings].
*
* Returns: %TRUE if there was a valid format string
*
* Since: 2.24
*/
gboolean
g_variant_format_string_scan (const gchar *string,
const gchar *limit,
const gchar **endptr)
{
#define next_char() (string == limit ? '\0' : *string++)
#define peek_char() (string == limit ? '\0' : *string)
char c;
switch (next_char())
{
case 'b': case 'y': case 'n': case 'q': case 'i': case 'u':
case 'x': case 't': case 'h': case 'd': case 's': case 'o':
case 'g': case 'v': case '*': case '?': case 'r':
break;
case 'm':
return g_variant_format_string_scan (string, limit, endptr);
case 'a':
case '@':
return g_variant_type_string_scan (string, limit, endptr);
case '(':
while (peek_char() != ')')
if (!g_variant_format_string_scan (string, limit, &string))
return FALSE;
next_char(); /* consume ')' */
break;
case '{':
c = next_char();
if (c == '&')
{
c = next_char ();
if (c != 's' && c != 'o' && c != 'g')
return FALSE;
}
else
{
if (c == '@')
c = next_char ();
/* ISO/IEC 9899:1999 (C99) §7.21.5.2:
* The terminating null character is considered to be
* part of the string.
*/
if (c != '\0' && strchr ("bynqiuxthdsog?", c) == NULL)
return FALSE;
}
if (!g_variant_format_string_scan (string, limit, &string))
return FALSE;
if (next_char() != '}')
return FALSE;
break;
case '^':
if ((c = next_char()) == 'a')
{
if ((c = next_char()) == '&')
{
if ((c = next_char()) == 'a')
{
if ((c = next_char()) == 'y')
break; /* '^a&ay' */
}
else if (c == 's' || c == 'o')
break; /* '^a&s', '^a&o' */
}
else if (c == 'a')
{
if ((c = next_char()) == 'y')
break; /* '^aay' */
}
else if (c == 's' || c == 'o')
break; /* '^as', '^ao' */
else if (c == 'y')
break; /* '^ay' */
}
else if (c == '&')
{
if ((c = next_char()) == 'a')
{
if ((c = next_char()) == 'y')
break; /* '^&ay' */
}
}
return FALSE;
case '&':
c = next_char();
if (c != 's' && c != 'o' && c != 'g')
return FALSE;
break;
default:
return FALSE;
}
if (endptr != NULL)
*endptr = string;
#undef next_char
#undef peek_char
return TRUE;
}
/**
* g_variant_check_format_string:
* @value: a #GVariant
* @format_string: a valid #GVariant format string
* @copy_only: %TRUE to ensure the format string makes deep copies
*
* Checks if calling g_variant_get() with @format_string on @value would
* be valid from a type-compatibility standpoint. @format_string is
* assumed to be a valid format string (from a syntactic standpoint).
*
* If @copy_only is %TRUE then this function additionally checks that it
* would be safe to call g_variant_unref() on @value immediately after
* the call to g_variant_get() without invalidating the result. This is
* only possible if deep copies are made (ie: there are no pointers to
* the data inside of the soon-to-be-freed #GVariant instance). If this
* check fails then a g_critical() is printed and %FALSE is returned.
*
* This function is meant to be used by functions that wish to provide
* varargs accessors to #GVariant values of uncertain values (eg:
* g_variant_lookup() or g_menu_model_get_item_attribute()).
*
* Returns: %TRUE if @format_string is safe to use
*
* Since: 2.34
*/
gboolean
g_variant_check_format_string (GVariant *value,
const gchar *format_string,
gboolean copy_only)
{
const gchar *original_format = format_string;
const gchar *type_string;
/* Interesting factoid: assuming a format string is valid, it can be
* converted to a type string by removing all '@' '&' and '^'
* characters.
*
* Instead of doing that, we can just skip those characters when
* comparing it to the type string of @value.
*
* For the copy-only case we can just drop the '&' from the list of
* characters to skip over. A '&' will never appear in a type string
* so we know that it won't be possible to return %TRUE if it is in a
* format string.
*/
type_string = g_variant_get_type_string (value);
while (*type_string || *format_string)
{
gchar format = *format_string++;
switch (format)
{
case '&':
if G_UNLIKELY (copy_only)
{
/* for the love of all that is good, please don't mark this string for translation... */
g_critical ("g_variant_check_format_string() is being called by a function with a GVariant varargs "
"interface to validate the passed format string for type safety. The passed format "
"(%s) contains a '&' character which would result in a pointer being returned to the "
"data inside of a GVariant instance that may no longer exist by the time the function "
"returns. Modify your code to use a format string without '&'.", original_format);
return FALSE;
}
/* fall through */
case '^':
case '@':
/* ignore these 2 (or 3) */
continue;
case '?':
/* attempt to consume one of 'bynqiuxthdsog' */
{
char s = *type_string++;
if (s == '\0' || strchr ("bynqiuxthdsog", s) == NULL)
return FALSE;
}
continue;
case 'r':
/* ensure it's a tuple */
if (*type_string != '(')
return FALSE;
/* fall through */
case '*':
/* consume a full type string for the '*' or 'r' */
if (!g_variant_type_string_scan (type_string, NULL, &type_string))
return FALSE;
continue;
default:
/* attempt to consume exactly one character equal to the format */
if (format != *type_string++)
return FALSE;
}
}
return TRUE;
}
/*< private >
* g_variant_format_string_scan_type:
* @string: a string that may be prefixed with a format string
* @limit: (nullable) (default NULL): a pointer to the end of @string,
* or %NULL
* @endptr: (nullable) (default NULL): location to store the end pointer,
* or %NULL
*
* If @string starts with a valid format string then this function will
* return the type that the format string corresponds to. Otherwise
* this function returns %NULL.
*
* Use g_variant_type_free() to free the return value when you no longer
* need it.
*
* This function is otherwise exactly like
* g_variant_format_string_scan().
*
* Returns: (nullable): a #GVariantType if there was a valid format string
*
* Since: 2.24
*/
GVariantType *
g_variant_format_string_scan_type (const gchar *string,
const gchar *limit,
const gchar **endptr)
{
const gchar *my_end;
gchar *dest;
gchar *new;
if (endptr == NULL)
endptr = &my_end;
if (!g_variant_format_string_scan (string, limit, endptr))
return NULL;
dest = new = g_malloc (*endptr - string + 1);
while (string != *endptr)
{
if (*string != '@' && *string != '&' && *string != '^')
*dest++ = *string;
string++;
}
*dest = '\0';
return (GVariantType *) G_VARIANT_TYPE (new);
}
static gboolean
valid_format_string (const gchar *format_string,
gboolean single,
GVariant *value)
{
const gchar *endptr;
GVariantType *type;
type = g_variant_format_string_scan_type (format_string, NULL, &endptr);
if G_UNLIKELY (type == NULL || (single && *endptr != '\0'))
{
if (single)
g_critical ("'%s' is not a valid GVariant format string",
format_string);
else
g_critical ("'%s' does not have a valid GVariant format "
"string as a prefix", format_string);
if (type != NULL)
g_variant_type_free (type);
return FALSE;
}
if G_UNLIKELY (value && !g_variant_is_of_type (value, type))
{
gchar *fragment;
gchar *typestr;
fragment = g_strndup (format_string, endptr - format_string);
typestr = g_variant_type_dup_string (type);
g_critical ("the GVariant format string '%s' has a type of "
"'%s' but the given value has a type of '%s'",
fragment, typestr, g_variant_get_type_string (value));
g_variant_type_free (type);
g_free (fragment);
g_free (typestr);
return FALSE;
}
g_variant_type_free (type);
return TRUE;
}
/* Variable Arguments {{{1 */
/* We consider 2 main classes of format strings:
*
* - recursive format strings
* these are ones that result in recursion and the collection of
* possibly more than one argument. Maybe types, tuples,
* dictionary entries.
*
* - leaf format string
* these result in the collection of a single argument.
*
* Leaf format strings are further subdivided into two categories:
*
* - single non-null pointer ("nnp")
* these either collect or return a single non-null pointer.
*
* - other
* these collect or return something else (bool, number, etc).
*
* Based on the above, the varargs handling code is split into 4 main parts:
*
* - nnp handling code
* - leaf handling code (which may invoke nnp code)
* - generic handling code (may be recursive, may invoke leaf code)
* - user-facing API (which invokes the generic code)
*
* Each section implements some of the following functions:
*
* - skip:
* collect the arguments for the format string as if
* g_variant_new() had been called, but do nothing with them. used
* for skipping over arguments when constructing a Nothing maybe
* type.
*
* - new:
* create a GVariant *
*
* - get:
* unpack a GVariant *
*
* - free (nnp only):
* free a previously allocated item
*/
static gboolean
g_variant_format_string_is_leaf (const gchar *str)
{
return str[0] != 'm' && str[0] != '(' && str[0] != '{';
}
static gboolean
g_variant_format_string_is_nnp (const gchar *str)
{
return str[0] == 'a' || str[0] == 's' || str[0] == 'o' || str[0] == 'g' ||
str[0] == '^' || str[0] == '@' || str[0] == '*' || str[0] == '?' ||
str[0] == 'r' || str[0] == 'v' || str[0] == '&';
}
/* Single non-null pointer ("nnp") {{{2 */
static void
g_variant_valist_free_nnp (const gchar *str,
gpointer ptr)
{
switch (*str)
{
case 'a':
g_variant_iter_free (ptr);
break;
case '^':
if (str[2] != '&') /* '^as', '^ao' */
g_strfreev (ptr);
else /* '^a&s', '^a&o' */
g_free (ptr);
break;
case 's':
case 'o':
case 'g':
g_free (ptr);
break;
case '@':
case '*':
case '?':
case 'v':
g_variant_unref (ptr);
break;
case '&':
break;
default:
g_assert_not_reached ();
}
}
static gchar
g_variant_scan_convenience (const gchar **str,
gboolean *constant,
guint *arrays)
{
*constant = FALSE;
*arrays = 0;
for (;;)
{
char c = *(*str)++;
if (c == '&')
*constant = TRUE;
else if (c == 'a')
(*arrays)++;
else
return c;
}
}
static GVariant *
g_variant_valist_new_nnp (const gchar **str,
gpointer ptr)
{
if (**str == '&')
(*str)++;
switch (*(*str)++)
{
case 'a':
if (ptr != NULL)
{
const GVariantType *type;
GVariant *value;
value = g_variant_builder_end (ptr);
type = g_variant_get_type (value);
if G_UNLIKELY (!g_variant_type_is_array (type))
g_error ("g_variant_new: expected array GVariantBuilder but "
"the built value has type '%s'",
g_variant_get_type_string (value));
type = g_variant_type_element (type);
if G_UNLIKELY (!g_variant_type_is_subtype_of (type, (GVariantType *) *str))
g_error ("g_variant_new: expected GVariantBuilder array element "
"type '%s' but the built value has element type '%s'",
g_variant_type_dup_string ((GVariantType *) *str),
g_variant_get_type_string (value) + 1);
g_variant_type_string_scan (*str, NULL, str);
return value;
}
else
/* special case: NULL pointer for empty array */
{
const GVariantType *type = (GVariantType *) *str;
g_variant_type_string_scan (*str, NULL, str);
if G_UNLIKELY (!g_variant_type_is_definite (type))
g_error ("g_variant_new: NULL pointer given with indefinite "
"array type; unable to determine which type of empty "
"array to construct.");
return g_variant_new_array (type, NULL, 0);
}
case 's':
{
GVariant *value;
value = g_variant_new_string (ptr);
if (value == NULL)
value = g_variant_new_string ("[Invalid UTF-8]");
return value;
}
case 'o':
return g_variant_new_object_path (ptr);
case 'g':
return g_variant_new_signature (ptr);
case '^':
{
gboolean constant;
guint arrays;
gchar type;
type = g_variant_scan_convenience (str, &constant, &arrays);
if (type == 's')
return g_variant_new_strv (ptr, -1);
if (type == 'o')
return g_variant_new_objv (ptr, -1);
if (arrays > 1)
return g_variant_new_bytestring_array (ptr, -1);
return g_variant_new_bytestring (ptr);
}
case '@':
if G_UNLIKELY (!g_variant_is_of_type (ptr, (GVariantType *) *str))
g_error ("g_variant_new: expected GVariant of type '%s' but "
"received value has type '%s'",
g_variant_type_dup_string ((GVariantType *) *str),
g_variant_get_type_string (ptr));
g_variant_type_string_scan (*str, NULL, str);
return ptr;
case '*':
return ptr;
case '?':
if G_UNLIKELY (!g_variant_type_is_basic (g_variant_get_type (ptr)))
g_error ("g_variant_new: format string '?' expects basic-typed "
"GVariant, but received value has type '%s'",
g_variant_get_type_string (ptr));
return ptr;
case 'r':
if G_UNLIKELY (!g_variant_type_is_tuple (g_variant_get_type (ptr)))
g_error ("g_variant_new: format string 'r' expects tuple-typed "
"GVariant, but received value has type '%s'",
g_variant_get_type_string (ptr));
return ptr;
case 'v':
return g_variant_new_variant (ptr);
default:
g_assert_not_reached ();
}
}
static gpointer
g_variant_valist_get_nnp (const gchar **str,
GVariant *value)
{
switch (*(*str)++)
{
case 'a':
g_variant_type_string_scan (*str, NULL, str);
return g_variant_iter_new (value);
case '&':
(*str)++;
return (gchar *) g_variant_get_string (value, NULL);
case 's':
case 'o':
case 'g':
return g_variant_dup_string (value, NULL);
case '^':
{
gboolean constant;
guint arrays;
gchar type;
type = g_variant_scan_convenience (str, &constant, &arrays);
if (type == 's')
{
if (constant)
return g_variant_get_strv (value, NULL);
else
return g_variant_dup_strv (value, NULL);
}
else if (type == 'o')
{
if (constant)
return g_variant_get_objv (value, NULL);
else
return g_variant_dup_objv (value, NULL);
}
else if (arrays > 1)
{
if (constant)
return g_variant_get_bytestring_array (value, NULL);
else
return g_variant_dup_bytestring_array (value, NULL);
}
else
{
if (constant)
return (gchar *) g_variant_get_bytestring (value);
else
return g_variant_dup_bytestring (value, NULL);
}
}
case '@':
g_variant_type_string_scan (*str, NULL, str);
/* fall through */
case '*':
case '?':
case 'r':
return g_variant_ref (value);
case 'v':
return g_variant_get_variant (value);
default:
g_assert_not_reached ();
}
}
/* Leaves {{{2 */
static void
g_variant_valist_skip_leaf (const gchar **str,
va_list *app)
{
if (g_variant_format_string_is_nnp (*str))
{
g_variant_format_string_scan (*str, NULL, str);
va_arg (*app, gpointer);
return;
}
switch (*(*str)++)
{
case 'b':
case 'y':
case 'n':
case 'q':
case 'i':
case 'u':
case 'h':
va_arg (*app, int);
return;
case 'x':
case 't':
va_arg (*app, guint64);
return;
case 'd':
va_arg (*app, gdouble);
return;
default:
g_assert_not_reached ();
}
}
static GVariant *
g_variant_valist_new_leaf (const gchar **str,
va_list *app)
{
if (g_variant_format_string_is_nnp (*str))
return g_variant_valist_new_nnp (str, va_arg (*app, gpointer));
switch (*(*str)++)
{
case 'b':
return g_variant_new_boolean (va_arg (*app, gboolean));
case 'y':
return g_variant_new_byte (va_arg (*app, guint));
case 'n':
return g_variant_new_int16 (va_arg (*app, gint));
case 'q':
return g_variant_new_uint16 (va_arg (*app, guint));
case 'i':
return g_variant_new_int32 (va_arg (*app, gint));
case 'u':
return g_variant_new_uint32 (va_arg (*app, guint));
case 'x':
return g_variant_new_int64 (va_arg (*app, gint64));
case 't':
return g_variant_new_uint64 (va_arg (*app, guint64));
case 'h':
return g_variant_new_handle (va_arg (*app, gint));
case 'd':
return g_variant_new_double (va_arg (*app, gdouble));
default:
g_assert_not_reached ();
}
}
/* The code below assumes this */
G_STATIC_ASSERT (sizeof (gboolean) == sizeof (guint32));
G_STATIC_ASSERT (sizeof (gdouble) == sizeof (guint64));
static void
g_variant_valist_get_leaf (const gchar **str,
GVariant *value,
gboolean free,
va_list *app)
{
gpointer ptr = va_arg (*app, gpointer);
if (ptr == NULL)
{
g_variant_format_string_scan (*str, NULL, str);
return;
}
if (g_variant_format_string_is_nnp (*str))
{
gpointer *nnp = (gpointer *) ptr;
if (free && *nnp != NULL)
g_variant_valist_free_nnp (*str, *nnp);
*nnp = NULL;
if (value != NULL)
*nnp = g_variant_valist_get_nnp (str, value);
else
g_variant_format_string_scan (*str, NULL, str);
return;
}
if (value != NULL)
{
switch (*(*str)++)
{
case 'b':
*(gboolean *) ptr = g_variant_get_boolean (value);
return;
case 'y':
*(guint8 *) ptr = g_variant_get_byte (value);
return;
case 'n':
*(gint16 *) ptr = g_variant_get_int16 (value);
return;
case 'q':
*(guint16 *) ptr = g_variant_get_uint16 (value);
return;
case 'i':
*(gint32 *) ptr = g_variant_get_int32 (value);
return;
case 'u':
*(guint32 *) ptr = g_variant_get_uint32 (value);
return;
case 'x':
*(gint64 *) ptr = g_variant_get_int64 (value);
return;
case 't':
*(guint64 *) ptr = g_variant_get_uint64 (value);
return;
case 'h':
*(gint32 *) ptr = g_variant_get_handle (value);
return;
case 'd':
*(gdouble *) ptr = g_variant_get_double (value);
return;
}
}
else
{
switch (*(*str)++)
{
case 'y':
*(guint8 *) ptr = 0;
return;
case 'n':
case 'q':
*(guint16 *) ptr = 0;
return;
case 'i':
case 'u':
case 'h':
case 'b':
*(guint32 *) ptr = 0;
return;
case 'x':
case 't':
case 'd':
*(guint64 *) ptr = 0;
return;
}
}
g_assert_not_reached ();
}
/* Generic (recursive) {{{2 */
static void
g_variant_valist_skip (const gchar **str,
va_list *app)
{
if (g_variant_format_string_is_leaf (*str))
g_variant_valist_skip_leaf (str, app);
else if (**str == 'm') /* maybe */
{
(*str)++;
if (!g_variant_format_string_is_nnp (*str))
va_arg (*app, gboolean);
g_variant_valist_skip (str, app);
}
else /* tuple, dictionary entry */
{
g_assert (**str == '(' || **str == '{');
(*str)++;
while (**str != ')' && **str != '}')
g_variant_valist_skip (str, app);
(*str)++;
}
}
static GVariant *
g_variant_valist_new (const gchar **str,
va_list *app)
{
if (g_variant_format_string_is_leaf (*str))
return g_variant_valist_new_leaf (str, app);
if (**str == 'm') /* maybe */
{
GVariantType *type = NULL;
GVariant *value = NULL;
(*str)++;
if (g_variant_format_string_is_nnp (*str))
{
gpointer nnp = va_arg (*app, gpointer);
if (nnp != NULL)
value = g_variant_valist_new_nnp (str, nnp);
else
type = g_variant_format_string_scan_type (*str, NULL, str);
}
else
{
gboolean just = va_arg (*app, gboolean);
if (just)
value = g_variant_valist_new (str, app);
else
{
type = g_variant_format_string_scan_type (*str, NULL, NULL);
g_variant_valist_skip (str, app);
}
}
value = g_variant_new_maybe (type, value);
if (type != NULL)
g_variant_type_free (type);
return value;
}
else /* tuple, dictionary entry */
{
GVariantBuilder b;
if (**str == '(')
g_variant_builder_init (&b, G_VARIANT_TYPE_TUPLE);
else
{
g_assert (**str == '{');
g_variant_builder_init (&b, G_VARIANT_TYPE_DICT_ENTRY);
}
(*str)++; /* '(' */
while (**str != ')' && **str != '}')
g_variant_builder_add_value (&b, g_variant_valist_new (str, app));
(*str)++; /* ')' */
return g_variant_builder_end (&b);
}
}
static void
g_variant_valist_get (const gchar **str,
GVariant *value,
gboolean free,
va_list *app)
{
if (g_variant_format_string_is_leaf (*str))
g_variant_valist_get_leaf (str, value, free, app);
else if (**str == 'm')
{
(*str)++;
if (value != NULL)
value = g_variant_get_maybe (value);
if (!g_variant_format_string_is_nnp (*str))
{
gboolean *ptr = va_arg (*app, gboolean *);
if (ptr != NULL)
*ptr = value != NULL;
}
g_variant_valist_get (str, value, free, app);
if (value != NULL)
g_variant_unref (value);
}
else /* tuple, dictionary entry */
{
gint index = 0;
g_assert (**str == '(' || **str == '{');
(*str)++;
while (**str != ')' && **str != '}')
{
if (value != NULL)
{
GVariant *child = g_variant_get_child_value (value, index++);
g_variant_valist_get (str, child, free, app);
g_variant_unref (child);
}
else
g_variant_valist_get (str, NULL, free, app);
}
(*str)++;
}
}
/* User-facing API {{{2 */
/**
* g_variant_new: (skip)
* @format_string: a #GVariant format string
* @...: arguments, as per @format_string
*
* Creates a new #GVariant instance.
*
* Think of this function as an analogue to g_strdup_printf().
*
* The type of the created instance and the arguments that are expected
* by this function are determined by @format_string. See the section on
* [GVariant format strings][gvariant-format-strings]. Please note that
* the syntax of the format string is very likely to be extended in the
* future.
*
* The first character of the format string must not be '*' '?' '@' or
* 'r'; in essence, a new #GVariant must always be constructed by this
* function (and not merely passed through it unmodified).
*
* Note that the arguments must be of the correct width for their types
* specified in @format_string. This can be achieved by casting them. See
* the [GVariant varargs documentation][gvariant-varargs].
*
* |[<!-- language="C" -->
* MyFlags some_flags = FLAG_ONE | FLAG_TWO;
* const gchar *some_strings[] = { "a", "b", "c", NULL };
* GVariant *new_variant;
*
* new_variant = g_variant_new ("(t^as)",
* // This cast is required.
* (guint64) some_flags,
* some_strings);
* ]|
*
* Returns: a new floating #GVariant instance
*
* Since: 2.24
**/
GVariant *
g_variant_new (const gchar *format_string,
...)
{
GVariant *value;
va_list ap;
g_return_val_if_fail (valid_format_string (format_string, TRUE, NULL) &&
format_string[0] != '?' && format_string[0] != '@' &&
format_string[0] != '*' && format_string[0] != 'r',
NULL);
va_start (ap, format_string);
value = g_variant_new_va (format_string, NULL, &ap);
va_end (ap);
return value;
}
/**
* g_variant_new_va: (skip)
* @format_string: a string that is prefixed with a format string
* @endptr: (nullable) (default NULL): location to store the end pointer,
* or %NULL
* @app: a pointer to a #va_list
*
* This function is intended to be used by libraries based on
* #GVariant that want to provide g_variant_new()-like functionality
* to their users.
*
* The API is more general than g_variant_new() to allow a wider range
* of possible uses.
*
* @format_string must still point to a valid format string, but it only
* needs to be nul-terminated if @endptr is %NULL. If @endptr is
* non-%NULL then it is updated to point to the first character past the
* end of the format string.
*
* @app is a pointer to a #va_list. The arguments, according to
* @format_string, are collected from this #va_list and the list is left
* pointing to the argument following the last.
*
* Note that the arguments in @app must be of the correct width for their
* types specified in @format_string when collected into the #va_list.
* See the [GVariant varargs documentation][gvariant-varargs].
*
* These two generalisations allow mixing of multiple calls to
* g_variant_new_va() and g_variant_get_va() within a single actual
* varargs call by the user.
*
* The return value will be floating if it was a newly created GVariant
* instance (for example, if the format string was "(ii)"). In the case
* that the format_string was '*', '?', 'r', or a format starting with
* '@' then the collected #GVariant pointer will be returned unmodified,
* without adding any additional references.
*
* In order to behave correctly in all cases it is necessary for the
* calling function to g_variant_ref_sink() the return result before
* returning control to the user that originally provided the pointer.
* At this point, the caller will have their own full reference to the
* result. This can also be done by adding the result to a container,
* or by passing it to another g_variant_new() call.
*
* Returns: a new, usually floating, #GVariant
*
* Since: 2.24
**/
GVariant *
g_variant_new_va (const gchar *format_string,
const gchar **endptr,
va_list *app)
{
GVariant *value;
g_return_val_if_fail (valid_format_string (format_string, !endptr, NULL),
NULL);
g_return_val_if_fail (app != NULL, NULL);
value = g_variant_valist_new (&format_string, app);
if (endptr != NULL)
*endptr = format_string;
return value;
}
/**
* g_variant_get: (skip)
* @value: a #GVariant instance
* @format_string: a #GVariant format string
* @...: arguments, as per @format_string
*
* Deconstructs a #GVariant instance.
*
* Think of this function as an analogue to scanf().
*
* The arguments that are expected by this function are entirely
* determined by @format_string. @format_string also restricts the
* permissible types of @value. It is an error to give a value with
* an incompatible type. See the section on
* [GVariant format strings][gvariant-format-strings].
* Please note that the syntax of the format string is very likely to be
* extended in the future.
*
* @format_string determines the C types that are used for unpacking
* the values and also determines if the values are copied or borrowed,
* see the section on
* [GVariant format strings][gvariant-format-strings-pointers].
*
* Since: 2.24
**/
void
g_variant_get (GVariant *value,
const gchar *format_string,
...)
{
va_list ap;
g_return_if_fail (valid_format_string (format_string, TRUE, value));
/* if any direct-pointer-access formats are in use, flatten first */
if (strchr (format_string, '&'))
g_variant_get_data (value);
va_start (ap, format_string);
g_variant_get_va (value, format_string, NULL, &ap);
va_end (ap);
}
/**
* g_variant_get_va: (skip)
* @value: a #GVariant
* @format_string: a string that is prefixed with a format string
* @endptr: (nullable) (default NULL): location to store the end pointer,
* or %NULL
* @app: a pointer to a #va_list
*
* This function is intended to be used by libraries based on #GVariant
* that want to provide g_variant_get()-like functionality to their
* users.
*
* The API is more general than g_variant_get() to allow a wider range
* of possible uses.
*
* @format_string must still point to a valid format string, but it only
* need to be nul-terminated if @endptr is %NULL. If @endptr is
* non-%NULL then it is updated to point to the first character past the
* end of the format string.
*
* @app is a pointer to a #va_list. The arguments, according to
* @format_string, are collected from this #va_list and the list is left
* pointing to the argument following the last.
*
* These two generalisations allow mixing of multiple calls to
* g_variant_new_va() and g_variant_get_va() within a single actual
* varargs call by the user.
*
* @format_string determines the C types that are used for unpacking
* the values and also determines if the values are copied or borrowed,
* see the section on
* [GVariant format strings][gvariant-format-strings-pointers].
*
* Since: 2.24
**/
void
g_variant_get_va (GVariant *value,
const gchar *format_string,
const gchar **endptr,
va_list *app)
{
g_return_if_fail (valid_format_string (format_string, !endptr, value));
g_return_if_fail (value != NULL);
g_return_if_fail (app != NULL);
/* if any direct-pointer-access formats are in use, flatten first */
if (strchr (format_string, '&'))
g_variant_get_data (value);
g_variant_valist_get (&format_string, value, FALSE, app);
if (endptr != NULL)
*endptr = format_string;
}
/* Varargs-enabled Utility Functions {{{1 */
/**
* g_variant_builder_add: (skip)
* @builder: a #GVariantBuilder
* @format_string: a #GVariant varargs format string
* @...: arguments, as per @format_string
*
* Adds to a #GVariantBuilder.
*
* This call is a convenience wrapper that is exactly equivalent to
* calling g_variant_new() followed by g_variant_builder_add_value().
*
* Note that the arguments must be of the correct width for their types
* specified in @format_string. This can be achieved by casting them. See
* the [GVariant varargs documentation][gvariant-varargs].
*
* This function might be used as follows:
*
* |[<!-- language="C" -->
* GVariant *
* make_pointless_dictionary (void)
* {
* GVariantBuilder builder;
* int i;
*
* g_variant_builder_init (&builder, G_VARIANT_TYPE_ARRAY);
* for (i = 0; i < 16; i++)
* {
* gchar buf[3];
*
* sprintf (buf, "%d", i);
* g_variant_builder_add (&builder, "{is}", i, buf);
* }
*
* return g_variant_builder_end (&builder);
* }
* ]|
*
* Since: 2.24
*/
void
g_variant_builder_add (GVariantBuilder *builder,
const gchar *format_string,
...)
{
GVariant *variant;
va_list ap;
va_start (ap, format_string);
variant = g_variant_new_va (format_string, NULL, &ap);
va_end (ap);
g_variant_builder_add_value (builder, variant);
}
/**
* g_variant_get_child: (skip)
* @value: a container #GVariant
* @index_: the index of the child to deconstruct
* @format_string: a #GVariant format string
* @...: arguments, as per @format_string
*
* Reads a child item out of a container #GVariant instance and
* deconstructs it according to @format_string. This call is
* essentially a combination of g_variant_get_child_value() and
* g_variant_get().
*
* @format_string determines the C types that are used for unpacking
* the values and also determines if the values are copied or borrowed,
* see the section on
* [GVariant format strings][gvariant-format-strings-pointers].
*
* Since: 2.24
**/
void
g_variant_get_child (GVariant *value,
gsize index_,
const gchar *format_string,
...)
{
GVariant *child;
va_list ap;
/* if any direct-pointer-access formats are in use, flatten first */
if (strchr (format_string, '&'))
g_variant_get_data (value);
child = g_variant_get_child_value (value, index_);
g_return_if_fail (valid_format_string (format_string, TRUE, child));
va_start (ap, format_string);
g_variant_get_va (child, format_string, NULL, &ap);
va_end (ap);
g_variant_unref (child);
}
/**
* g_variant_iter_next: (skip)
* @iter: a #GVariantIter
* @format_string: a GVariant format string
* @...: the arguments to unpack the value into
*
* Gets the next item in the container and unpacks it into the variable
* argument list according to @format_string, returning %TRUE.
*
* If no more items remain then %FALSE is returned.
*
* All of the pointers given on the variable arguments list of this
* function are assumed to point at uninitialised memory. It is the
* responsibility of the caller to free all of the values returned by
* the unpacking process.
*
* Here is an example for memory management with g_variant_iter_next():
* |[<!-- language="C" -->
* // Iterates a dictionary of type 'a{sv}'
* void
* iterate_dictionary (GVariant *dictionary)
* {
* GVariantIter iter;
* GVariant *value;
* gchar *key;
*
* g_variant_iter_init (&iter, dictionary);
* while (g_variant_iter_next (&iter, "{sv}", &key, &value))
* {
* g_print ("Item '%s' has type '%s'\n", key,
* g_variant_get_type_string (value));
*
* // must free data for ourselves
* g_variant_unref (value);
* g_free (key);
* }
* }
* ]|
*
* For a solution that is likely to be more convenient to C programmers
* when dealing with loops, see g_variant_iter_loop().
*
* @format_string determines the C types that are used for unpacking
* the values and also determines if the values are copied or borrowed.
*
* See the section on
* [GVariant format strings][gvariant-format-strings-pointers].
*
* Returns: %TRUE if a value was unpacked, or %FALSE if there as no value
*
* Since: 2.24
**/
gboolean
g_variant_iter_next (GVariantIter *iter,
const gchar *format_string,
...)
{
GVariant *value;
value = g_variant_iter_next_value (iter);
g_return_val_if_fail (valid_format_string (format_string, TRUE, value),
FALSE);
if (value != NULL)
{
va_list ap;
va_start (ap, format_string);
g_variant_valist_get (&format_string, value, FALSE, &ap);
va_end (ap);
g_variant_unref (value);
}
return value != NULL;
}
/**
* g_variant_iter_loop: (skip)
* @iter: a #GVariantIter
* @format_string: a GVariant format string
* @...: the arguments to unpack the value into
*
* Gets the next item in the container and unpacks it into the variable
* argument list according to @format_string, returning %TRUE.
*
* If no more items remain then %FALSE is returned.
*
* On the first call to this function, the pointers appearing on the
* variable argument list are assumed to point at uninitialised memory.
* On the second and later calls, it is assumed that the same pointers
* will be given and that they will point to the memory as set by the
* previous call to this function. This allows the previous values to
* be freed, as appropriate.
*
* This function is intended to be used with a while loop as
* demonstrated in the following example. This function can only be
* used when iterating over an array. It is only valid to call this
* function with a string constant for the format string and the same
* string constant must be used each time. Mixing calls to this
* function and g_variant_iter_next() or g_variant_iter_next_value() on
* the same iterator causes undefined behavior.
*
* If you break out of a such a while loop using g_variant_iter_loop() then
* you must free or unreference all the unpacked values as you would with
* g_variant_get(). Failure to do so will cause a memory leak.
*
* Here is an example for memory management with g_variant_iter_loop():
* |[<!-- language="C" -->
* // Iterates a dictionary of type 'a{sv}'
* void
* iterate_dictionary (GVariant *dictionary)
* {
* GVariantIter iter;
* GVariant *value;
* gchar *key;
*
* g_variant_iter_init (&iter, dictionary);
* while (g_variant_iter_loop (&iter, "{sv}", &key, &value))
* {
* g_print ("Item '%s' has type '%s'\n", key,
* g_variant_get_type_string (value));
*
* // no need to free 'key' and 'value' here
* // unless breaking out of this loop
* }
* }
* ]|
*
* For most cases you should use g_variant_iter_next().
*
* This function is really only useful when unpacking into #GVariant or
* #GVariantIter in order to allow you to skip the call to
* g_variant_unref() or g_variant_iter_free().
*
* For example, if you are only looping over simple integer and string
* types, g_variant_iter_next() is definitely preferred. For string
* types, use the '&' prefix to avoid allocating any memory at all (and
* thereby avoiding the need to free anything as well).
*
* @format_string determines the C types that are used for unpacking
* the values and also determines if the values are copied or borrowed.
*
* See the section on
* [GVariant format strings][gvariant-format-strings-pointers].
*
* Returns: %TRUE if a value was unpacked, or %FALSE if there was no
* value
*
* Since: 2.24
**/
gboolean
g_variant_iter_loop (GVariantIter *iter,
const gchar *format_string,
...)
{
gboolean first_time = GVSI(iter)->loop_format == NULL;
GVariant *value;
va_list ap;
g_return_val_if_fail (first_time ||
format_string == GVSI(iter)->loop_format,
FALSE);
if (first_time)
{
TYPE_CHECK (GVSI(iter)->value, G_VARIANT_TYPE_ARRAY, FALSE);
GVSI(iter)->loop_format = format_string;
if (strchr (format_string, '&'))
g_variant_get_data (GVSI(iter)->value);
}
value = g_variant_iter_next_value (iter);
g_return_val_if_fail (!first_time ||
valid_format_string (format_string, TRUE, value),
FALSE);
va_start (ap, format_string);
g_variant_valist_get (&format_string, value, !first_time, &ap);
va_end (ap);
if (value != NULL)
g_variant_unref (value);
return value != NULL;
}
/* Serialised data {{{1 */
static GVariant *
g_variant_deep_copy (GVariant *value)
{
switch (g_variant_classify (value))
{
case G_VARIANT_CLASS_MAYBE:
case G_VARIANT_CLASS_ARRAY:
case G_VARIANT_CLASS_TUPLE:
case G_VARIANT_CLASS_DICT_ENTRY:
case G_VARIANT_CLASS_VARIANT:
{
GVariantBuilder builder;
GVariantIter iter;
GVariant *child;
g_variant_builder_init (&builder, g_variant_get_type (value));
g_variant_iter_init (&iter, value);
while ((child = g_variant_iter_next_value (&iter)))
{
g_variant_builder_add_value (&builder, g_variant_deep_copy (child));
g_variant_unref (child);
}
return g_variant_builder_end (&builder);
}
case G_VARIANT_CLASS_BOOLEAN:
return g_variant_new_boolean (g_variant_get_boolean (value));
case G_VARIANT_CLASS_BYTE:
return g_variant_new_byte (g_variant_get_byte (value));
case G_VARIANT_CLASS_INT16:
return g_variant_new_int16 (g_variant_get_int16 (value));
case G_VARIANT_CLASS_UINT16:
return g_variant_new_uint16 (g_variant_get_uint16 (value));
case G_VARIANT_CLASS_INT32:
return g_variant_new_int32 (g_variant_get_int32 (value));
case G_VARIANT_CLASS_UINT32:
return g_variant_new_uint32 (g_variant_get_uint32 (value));
case G_VARIANT_CLASS_INT64:
return g_variant_new_int64 (g_variant_get_int64 (value));
case G_VARIANT_CLASS_UINT64:
return g_variant_new_uint64 (g_variant_get_uint64 (value));
case G_VARIANT_CLASS_HANDLE:
return g_variant_new_handle (g_variant_get_handle (value));
case G_VARIANT_CLASS_DOUBLE:
return g_variant_new_double (g_variant_get_double (value));
case G_VARIANT_CLASS_STRING:
return g_variant_new_string (g_variant_get_string (value, NULL));
case G_VARIANT_CLASS_OBJECT_PATH:
return g_variant_new_object_path (g_variant_get_string (value, NULL));
case G_VARIANT_CLASS_SIGNATURE:
return g_variant_new_signature (g_variant_get_string (value, NULL));
}
g_assert_not_reached ();
}
/**
* g_variant_get_normal_form:
* @value: a #GVariant
*
* Gets a #GVariant instance that has the same value as @value and is
* trusted to be in normal form.
*
* If @value is already trusted to be in normal form then a new
* reference to @value is returned.
*
* If @value is not already trusted, then it is scanned to check if it
* is in normal form. If it is found to be in normal form then it is
* marked as trusted and a new reference to it is returned.
*
* If @value is found not to be in normal form then a new trusted
* #GVariant is created with the same value as @value.
*
* It makes sense to call this function if you've received #GVariant
* data from untrusted sources and you want to ensure your serialised
* output is definitely in normal form.
*
* If @value is already in normal form, a new reference will be returned
* (which will be floating if @value is floating). If it is not in normal form,
* the newly created #GVariant will be returned with a single non-floating
* reference. Typically, g_variant_take_ref() should be called on the return
* value from this function to guarantee ownership of a single non-floating
* reference to it.
*
* Returns: (transfer full): a trusted #GVariant
*
* Since: 2.24
**/
GVariant *
g_variant_get_normal_form (GVariant *value)
{
GVariant *trusted;
if (g_variant_is_normal_form (value))
return g_variant_ref (value);
trusted = g_variant_deep_copy (value);
g_assert (g_variant_is_trusted (trusted));
return g_variant_ref_sink (trusted);
}
/**
* g_variant_byteswap:
* @value: a #GVariant
*
* Performs a byteswapping operation on the contents of @value. The
* result is that all multi-byte numeric data contained in @value is
* byteswapped. That includes 16, 32, and 64bit signed and unsigned
* integers as well as file handles and double precision floating point
* values.
*
* This function is an identity mapping on any value that does not
* contain multi-byte numeric data. That include strings, booleans,
* bytes and containers containing only these things (recursively).
*
* The returned value is always in normal form and is marked as trusted.
*
* Returns: (transfer full): the byteswapped form of @value
*
* Since: 2.24
**/
GVariant *
g_variant_byteswap (GVariant *value)
{
GVariantTypeInfo *type_info;
guint alignment;
GVariant *new;
type_info = g_variant_get_type_info (value);
g_variant_type_info_query (type_info, &alignment, NULL);
if (alignment)
/* (potentially) contains multi-byte numeric data */
{
GVariantSerialised serialised;
GVariant *trusted;
GBytes *bytes;
trusted = g_variant_get_normal_form (value);
serialised.type_info = g_variant_get_type_info (trusted);
serialised.size = g_variant_get_size (trusted);
serialised.data = g_malloc (serialised.size);
g_variant_store (trusted, serialised.data);
g_variant_unref (trusted);
g_variant_serialised_byteswap (serialised);
bytes = g_bytes_new_take (serialised.data, serialised.size);
new = g_variant_new_from_bytes (g_variant_get_type (value), bytes, TRUE);
g_bytes_unref (bytes);
}
else
/* contains no multi-byte data */
new = value;
return g_variant_ref_sink (new);
}
/**
* g_variant_new_from_data:
* @type: a definite #GVariantType
* @data: (array length=size) (element-type guint8): the serialised data
* @size: the size of @data
* @trusted: %TRUE if @data is definitely in normal form
* @notify: (scope async): function to call when @data is no longer needed
* @user_data: data for @notify
*
* Creates a new #GVariant instance from serialised data.
*
* @type is the type of #GVariant instance that will be constructed.
* The interpretation of @data depends on knowing the type.
*
* @data is not modified by this function and must remain valid with an
* unchanging value until such a time as @notify is called with
* @user_data. If the contents of @data change before that time then
* the result is undefined.
*
* If @data is trusted to be serialised data in normal form then
* @trusted should be %TRUE. This applies to serialised data created
* within this process or read from a trusted location on the disk (such
* as a file installed in /usr/lib alongside your application). You
* should set trusted to %FALSE if @data is read from the network, a
* file in the user's home directory, etc.
*
* If @data was not stored in this machine's native endianness, any multi-byte
* numeric values in the returned variant will also be in non-native
* endianness. g_variant_byteswap() can be used to recover the original values.
*
* @notify will be called with @user_data when @data is no longer
* needed. The exact time of this call is unspecified and might even be
* before this function returns.
*
* Returns: (transfer none): a new floating #GVariant of type @type
*
* Since: 2.24
**/
GVariant *
g_variant_new_from_data (const GVariantType *type,
gconstpointer data,
gsize size,
gboolean trusted,
GDestroyNotify notify,
gpointer user_data)
{
GVariant *value;
GBytes *bytes;
g_return_val_if_fail (g_variant_type_is_definite (type), NULL);
g_return_val_if_fail (data != NULL || size == 0, NULL);
if (notify)
bytes = g_bytes_new_with_free_func (data, size, notify, user_data);
else
bytes = g_bytes_new_static (data, size);
value = g_variant_new_from_bytes (type, bytes, trusted);
g_bytes_unref (bytes);
return value;
}
/* Epilogue {{{1 */
/* vim:set foldmethod=marker: */