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/*
* Copyright © 2007, 2008 Ryan Lortie
* Copyright © 2009, 2010 Codethink Limited
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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>
*/
#include "config.h"
#include "gvarianttype.h"
#include <glib/gtestutils.h>
#include <glib/gstrfuncs.h>
#include <glib/gvariant-internal.h>
#include <string.h>
/**
* GVariantType:
*
* A type in the [type@GLib.Variant] type system.
*
* This section introduces the [type@GLib.Variant] type system. It is based, in
* large part, on the D-Bus type system, with two major changes and
* some minor lifting of restrictions. The
* [D-Bus specification](http://dbus.freedesktop.org/doc/dbus-specification.html),
* therefore, provides a significant amount of
* information that is useful when working with [type@GLib.Variant].
*
* The first major change with respect to the D-Bus type system is the
* introduction of maybe (or ‘nullable’) types. Any type in [type@GLib.Variant]
* can be converted to a maybe type, in which case, `nothing` (or `null`)
* becomes a valid value. Maybe types have been added by introducing the
* character `m` to type strings.
*
* The second major change is that the [type@GLib.Variant] type system supports
* the concept of ‘indefinite types’ — types that are less specific than
* the normal types found in D-Bus. For example, it is possible to speak
* of ‘an array of any type’ in [type@GLib.Variant], where the D-Bus type system
* would require you to speak of ‘an array of integers’ or ‘an array of
* strings’. Indefinite types have been added by introducing the
* characters `*`, `?` and `r` to type strings.
*
* Finally, all arbitrary restrictions relating to the complexity of
* types are lifted along with the restriction that dictionary entries
* may only appear nested inside of arrays.
*
* Just as in D-Bus, [type@GLib.Variant] types are described with strings (‘type
* strings’). Subject to the differences mentioned above, these strings
* are of the same form as those found in D-Bus. Note, however: D-Bus
* always works in terms of messages and therefore individual type
* strings appear nowhere in its interface. Instead, ‘signatures’
* are a concatenation of the strings of the type of each argument in a
* message. [type@GLib.Variant] deals with single values directly so
* [type@GLib.Variant] type strings always describe the type of exactly one
* value. This means that a D-Bus signature string is generally not a valid
* [type@GLib.Variant] type string — except in the case that it is the signature
* of a message containing exactly one argument.
*
* An indefinite type is similar in spirit to what may be called an
* abstract type in other type systems. No value can exist that has an
* indefinite type as its type, but values can exist that have types
* that are subtypes of indefinite types. That is to say,
* [method@GLib.Variant.get_type] will never return an indefinite type, but
* calling [method@GLib.Variant.is_of_type] with an indefinite type may return
* true. For example, you cannot have a value that represents ‘an
* array of no particular type’, but you can have an ‘array of integers’
* which certainly matches the type of ‘an array of no particular type’,
* since ‘array of integers’ is a subtype of ‘array of no particular
* type’.
*
* This is similar to how instances of abstract classes may not
* directly exist in other type systems, but instances of their
* non-abstract subtypes may. For example, in GTK, no object that has
* the type of [`GtkWidget`](https://docs.gtk.org/gtk4/class.Widget.html) can
* exist (since `GtkWidget` is an abstract class), but a [`GtkWindow`](https://docs.gtk.org/gtk4/class.Window.html)
* can certainly be instantiated, and you would say that a `GtkWindow` is a
* `GtkWidget` (since `GtkWindow` is a subclass of `GtkWidget`).
*
* Two types may not be compared by value; use [method@GLib.VariantType.equal]
* or [method@GLib.VariantType.is_subtype_of] May be copied using
* [method@GLib.VariantType.copy] and freed using [method@GLib.VariantType.free].
*
* ## GVariant Type Strings
*
* A [type@GLib.Variant] type string can be any of the following:
*
* - any basic type string (listed below)
* - `v`, `r` or `*`
* - one of the characters `a` or `m`, followed by another type string
* - the character `(`, followed by a concatenation of zero or more other
* type strings, followed by the character `)`
* - the character `{`, followed by a basic type string (see below),
* followed by another type string, followed by the character `}`
*
* A basic type string describes a basic type (as per
* [method@GLib.VariantType.is_basic]) and is always a single character in
* length. The valid basic type strings are `b`, `y`, `n`, `q`, `i`, `u`, `x`,
* `t`, `h`, `d`, `s`, `o`, `g` and `?`.
*
* The above definition is recursive to arbitrary depth. `aaaaai` and
* `(ui(nq((y)))s)` are both valid type strings, as is
* `a(aa(ui)(qna{ya(yd)}))`. In order to not hit memory limits,
* [type@GLib.Variant] imposes a limit on recursion depth of 65 nested
* containers. This is the limit in the D-Bus specification (64) plus one to
* allow a [`GDBusMessage`](../gio/class.DBusMessage.html) to be nested in
* a top-level tuple.
*
* The meaning of each of the characters is as follows:
*
* - `b`: the type string of `G_VARIANT_TYPE_BOOLEAN`; a boolean value.
* - `y`: the type string of `G_VARIANT_TYPE_BYTE`; a byte.
* - `n`: the type string of `G_VARIANT_TYPE_INT16`; a signed 16 bit integer.
* - `q`: the type string of `G_VARIANT_TYPE_UINT16`; an unsigned 16 bit integer.
* - `i`: the type string of `G_VARIANT_TYPE_INT32`; a signed 32 bit integer.
* - `u`: the type string of `G_VARIANT_TYPE_UINT32`; an unsigned 32 bit integer.
* - `x`: the type string of `G_VARIANT_TYPE_INT64`; a signed 64 bit integer.
* - `t`: the type string of `G_VARIANT_TYPE_UINT64`; an unsigned 64 bit integer.
* - `h`: the type string of `G_VARIANT_TYPE_HANDLE`; a signed 32 bit value
* that, by convention, is used as an index into an array of file
* descriptors that are sent alongside a D-Bus message.
* - `d`: the type string of `G_VARIANT_TYPE_DOUBLE`; a double precision
* floating point value.
* - `s`: the type string of `G_VARIANT_TYPE_STRING`; a string.
* - `o`: the type string of `G_VARIANT_TYPE_OBJECT_PATH`; a string in the form
* of a D-Bus object path.
* - `g`: the type string of `G_VARIANT_TYPE_SIGNATURE`; a string in the form of
* a D-Bus type signature.
* - `?`: the type string of `G_VARIANT_TYPE_BASIC`; an indefinite type that
* is a supertype of any of the basic types.
* - `v`: the type string of `G_VARIANT_TYPE_VARIANT`; a container type that
* contain any other type of value.
* - `a`: used as a prefix on another type string to mean an array of that
* type; the type string `ai`, for example, is the type of an array of
* signed 32-bit integers.
* - `m`: used as a prefix on another type string to mean a ‘maybe’, or
* ‘nullable’, version of that type; the type string `ms`, for example,
* is the type of a value that maybe contains a string, or maybe contains
* nothing.
* - `()`: used to enclose zero or more other concatenated type strings to
* create a tuple type; the type string `(is)`, for example, is the type of
* a pair of an integer and a string.
* - `r`: the type string of `G_VARIANT_TYPE_TUPLE`; an indefinite type that is
* a supertype of any tuple type, regardless of the number of items.
* - `{}`: used to enclose a basic type string concatenated with another type
* string to create a dictionary entry type, which usually appears inside of
* an array to form a dictionary; the type string `a{sd}`, for example, is
* the type of a dictionary that maps strings to double precision floating
* point values.
*
* The first type (the basic type) is the key type and the second type is
* the value type. The reason that the first type is restricted to being a
* basic type is so that it can easily be hashed.
* - `*`: the type string of `G_VARIANT_TYPE_ANY`; the indefinite type that is
* a supertype of all types. Note that, as with all type strings, this
* character represents exactly one type. It cannot be used inside of tuples
* to mean ‘any number of items’.
*
* Any type string of a container that contains an indefinite type is,
* itself, an indefinite type. For example, the type string `a*`
* (corresponding to `G_VARIANT_TYPE_ARRAY`) is an indefinite type
* that is a supertype of every array type. `(*s)` is a supertype
* of all tuples that contain exactly two items where the second
* item is a string.
*
* `a{?*}` is an indefinite type that is a supertype of all arrays
* containing dictionary entries where the key is any basic type and
* the value is any type at all. This is, by definition, a dictionary,
* so this type string corresponds to `G_VARIANT_TYPE_DICTIONARY`. Note
* that, due to the restriction that the key of a dictionary entry must
* be a basic type, `{**}` is not a valid type string.
*
* Since: 2.24
*/
static gboolean
g_variant_type_check (const GVariantType *type)
{
if (type == NULL)
return FALSE;
#if 0
return g_variant_type_string_scan ((const gchar *) type, NULL, NULL);
#else
return TRUE;
#endif
}
static gboolean
variant_type_string_scan_internal (const gchar *string,
const gchar *limit,
const gchar **endptr,
gsize *depth,
gsize depth_limit)
{
gsize max_depth = 0, child_depth;
g_return_val_if_fail (string != NULL, FALSE);
if (string == limit || *string == '\0')
return FALSE;
switch (*string++)
{
case '(':
while (string == limit || *string != ')')
{
if (depth_limit == 0 ||
!variant_type_string_scan_internal (string, limit, &string,
&child_depth,
depth_limit - 1))
return FALSE;
max_depth = MAX (max_depth, child_depth + 1);
}
string++;
break;
case '{':
if (depth_limit == 0 ||
string == limit || *string == '\0' || /* { */
!strchr ("bynqihuxtdsog?", *string++) || /* key */
!variant_type_string_scan_internal (string, limit, &string,
&child_depth, depth_limit - 1) || /* value */
string == limit || *string++ != '}') /* } */
return FALSE;
max_depth = MAX (max_depth, child_depth + 1);
break;
case 'm': case 'a':
if (depth_limit == 0 ||
!variant_type_string_scan_internal (string, limit, &string,
&child_depth, depth_limit - 1))
return FALSE;
max_depth = MAX (max_depth, child_depth + 1);
break;
case 'b': case 'y': case 'n': case 'q': case 'i': case 'u':
case 'x': case 't': case 'd': case 's': case 'o': case 'g':
case 'v': case 'r': case '*': case '?': case 'h':
max_depth = MAX (max_depth, 1);
break;
default:
return FALSE;
}
if (endptr != NULL)
*endptr = string;
if (depth != NULL)
*depth = max_depth;
return TRUE;
}
/**
* g_variant_type_string_scan:
* @string: a pointer to any string
* @limit: (nullable): the end of @string, or %NULL
* @endptr: (out) (optional): location to store the end pointer, or %NULL
*
* Scan for a single complete and valid GVariant type string in @string.
* The memory pointed to by @limit (or bytes beyond it) is never
* accessed.
*
* If a valid type string is found, @endptr is updated to point to the
* first character past the end of the string that was found and %TRUE
* is returned.
*
* If there is no valid type string starting at @string, or if the type
* string does not end before @limit then %FALSE is returned.
*
* For the simple case of checking if a string is a valid type string,
* see g_variant_type_string_is_valid().
*
* Returns: %TRUE if a valid type string was found
*
* Since: 2.24
**/
gboolean
g_variant_type_string_scan (const gchar *string,
const gchar *limit,
const gchar **endptr)
{
return variant_type_string_scan_internal (string, limit, endptr, NULL,
G_VARIANT_MAX_RECURSION_DEPTH);
}
/* < private >
* g_variant_type_string_get_depth_:
* @type_string: a pointer to any string
*
* Get the maximum depth of the nested types in @type_string. A basic type will
* return depth 1, and a container type will return a greater value. The depth
* of a tuple is 1 plus the depth of its deepest child type.
*
* If @type_string is not a valid #GVariant type string, 0 will be returned.
*
* Returns: depth of @type_string, or 0 on error
* Since: 2.60
*/
gsize
g_variant_type_string_get_depth_ (const gchar *type_string)
{
const gchar *endptr;
gsize depth = 0;
g_return_val_if_fail (type_string != NULL, 0);
if (!variant_type_string_scan_internal (type_string, NULL, &endptr, &depth,
G_VARIANT_MAX_RECURSION_DEPTH) ||
*endptr != '\0')
return 0;
return depth;
}
/**
* g_variant_type_string_is_valid:
* @type_string: a pointer to any string
*
* Checks if @type_string is a valid GVariant type string. This call is
* equivalent to calling g_variant_type_string_scan() and confirming
* that the following character is a nul terminator.
*
* Returns: %TRUE if @type_string is exactly one valid type string
*
* Since 2.24
**/
gboolean
g_variant_type_string_is_valid (const gchar *type_string)
{
const gchar *endptr;
g_return_val_if_fail (type_string != NULL, FALSE);
if (!g_variant_type_string_scan (type_string, NULL, &endptr))
return FALSE;
return *endptr == '\0';
}
/**
* g_variant_type_free:
* @type: (nullable): a #GVariantType, or %NULL
*
* Frees a #GVariantType that was allocated with
* g_variant_type_copy(), g_variant_type_new() or one of the container
* type constructor functions.
*
* In the case that @type is %NULL, this function does nothing.
*
* Since 2.24
**/
void
g_variant_type_free (GVariantType *type)
{
g_return_if_fail (type == NULL || g_variant_type_check (type));
g_free (type);
}
/**
* g_variant_type_copy:
* @type: a #GVariantType
*
* Makes a copy of a #GVariantType. It is appropriate to call
* g_variant_type_free() on the return value. @type may not be %NULL.
*
* Returns: (transfer full): a new #GVariantType
*
* Since 2.24
**/
GVariantType *
g_variant_type_copy (const GVariantType *type)
{
gsize length;
gchar *new;
g_return_val_if_fail (g_variant_type_check (type), NULL);
length = g_variant_type_get_string_length (type);
new = g_malloc (length + 1);
memcpy (new, type, length);
new[length] = '\0';
return (GVariantType *) new;
}
/**
* g_variant_type_new:
* @type_string: a valid GVariant type string
*
* Creates a new #GVariantType corresponding to the type string given
* by @type_string. It is appropriate to call g_variant_type_free() on
* the return value.
*
* It is a programmer error to call this function with an invalid type
* string. Use g_variant_type_string_is_valid() if you are unsure.
*
* Returns: (transfer full): a new #GVariantType
*
* Since: 2.24
*/
GVariantType *
g_variant_type_new (const gchar *type_string)
{
g_return_val_if_fail (type_string != NULL, NULL);
return g_variant_type_copy (G_VARIANT_TYPE (type_string));
}
/**
* g_variant_type_get_string_length:
* @type: a #GVariantType
*
* Returns the length of the type string corresponding to the given
* @type. This function must be used to determine the valid extent of
* the memory region returned by g_variant_type_peek_string().
*
* Returns: the length of the corresponding type string
*
* Since 2.24
**/
gsize
g_variant_type_get_string_length (const GVariantType *type)
{
const gchar *type_string = (const gchar *) type;
gint brackets = 0;
gsize index = 0;
g_return_val_if_fail (g_variant_type_check (type), 0);
do
{
while (type_string[index] == 'a' || type_string[index] == 'm')
index++;
if (type_string[index] == '(' || type_string[index] == '{')
brackets++;
else if (type_string[index] == ')' || type_string[index] == '}')
brackets--;
index++;
}
while (brackets);
return index;
}
/*
This function is not introspectable, it returns something that
is not an array and neither a string
*/
/**
* g_variant_type_peek_string: (skip)
* @type: a #GVariantType
*
* Returns the type string corresponding to the given @type. The
* result is not nul-terminated; in order to determine its length you
* must call g_variant_type_get_string_length().
*
* To get a nul-terminated string, see g_variant_type_dup_string().
*
* Returns: the corresponding type string (not nul-terminated)
*
* Since 2.24
**/
const gchar *
g_variant_type_peek_string (const GVariantType *type)
{
g_return_val_if_fail (g_variant_type_check (type), NULL);
return (const gchar *) type;
}
/**
* g_variant_type_dup_string:
* @type: a #GVariantType
*
* Returns a newly-allocated copy of the type string corresponding to
* @type. The returned string is nul-terminated. It is appropriate to
* call g_free() on the return value.
*
* Returns: (transfer full): the corresponding type string
*
* Since 2.24
**/
gchar *
g_variant_type_dup_string (const GVariantType *type)
{
g_return_val_if_fail (g_variant_type_check (type), NULL);
return g_strndup (g_variant_type_peek_string (type),
g_variant_type_get_string_length (type));
}
/**
* g_variant_type_is_definite:
* @type: a #GVariantType
*
* Determines if the given @type is definite (ie: not indefinite).
*
* A type is definite if its type string does not contain any indefinite
* type characters ('*', '?', or 'r').
*
* A #GVariant instance may not have an indefinite type, so calling
* this function on the result of g_variant_get_type() will always
* result in %TRUE being returned. Calling this function on an
* indefinite type like %G_VARIANT_TYPE_ARRAY, however, will result in
* %FALSE being returned.
*
* Returns: %TRUE if @type is definite
*
* Since 2.24
**/
gboolean
g_variant_type_is_definite (const GVariantType *type)
{
const gchar *type_string;
gsize type_length;
gsize i;
g_return_val_if_fail (g_variant_type_check (type), FALSE);
type_length = g_variant_type_get_string_length (type);
type_string = g_variant_type_peek_string (type);
for (i = 0; i < type_length; i++)
if (type_string[i] == '*' ||
type_string[i] == '?' ||
type_string[i] == 'r')
return FALSE;
return TRUE;
}
/**
* g_variant_type_is_container:
* @type: a #GVariantType
*
* Determines if the given @type is a container type.
*
* Container types are any array, maybe, tuple, or dictionary
* entry types plus the variant type.
*
* This function returns %TRUE for any indefinite type for which every
* definite subtype is a container -- %G_VARIANT_TYPE_ARRAY, for
* example.
*
* Returns: %TRUE if @type is a container type
*
* Since 2.24
**/
gboolean
g_variant_type_is_container (const GVariantType *type)
{
gchar first_char;
g_return_val_if_fail (g_variant_type_check (type), FALSE);
first_char = g_variant_type_peek_string (type)[0];
switch (first_char)
{
case 'a':
case 'm':
case 'r':
case '(':
case '{':
case 'v':
return TRUE;
default:
return FALSE;
}
}
/**
* g_variant_type_is_basic:
* @type: a #GVariantType
*
* Determines if the given @type is a basic type.
*
* Basic types are booleans, bytes, integers, doubles, strings, object
* paths and signatures.
*
* Only a basic type may be used as the key of a dictionary entry.
*
* This function returns %FALSE for all indefinite types except
* %G_VARIANT_TYPE_BASIC.
*
* Returns: %TRUE if @type is a basic type
*
* Since 2.24
**/
gboolean
g_variant_type_is_basic (const GVariantType *type)
{
gchar first_char;
g_return_val_if_fail (g_variant_type_check (type), FALSE);
first_char = g_variant_type_peek_string (type)[0];
switch (first_char)
{
case 'b':
case 'y':
case 'n':
case 'q':
case 'i':
case 'h':
case 'u':
case 't':
case 'x':
case 'd':
case 's':
case 'o':
case 'g':
case '?':
return TRUE;
default:
return FALSE;
}
}
/**
* g_variant_type_is_maybe:
* @type: a #GVariantType
*
* Determines if the given @type is a maybe type. This is true if the
* type string for @type starts with an 'm'.
*
* This function returns %TRUE for any indefinite type for which every
* definite subtype is a maybe type -- %G_VARIANT_TYPE_MAYBE, for
* example.
*
* Returns: %TRUE if @type is a maybe type
*
* Since 2.24
**/
gboolean
g_variant_type_is_maybe (const GVariantType *type)
{
g_return_val_if_fail (g_variant_type_check (type), FALSE);
return g_variant_type_peek_string (type)[0] == 'm';
}
/**
* g_variant_type_is_array:
* @type: a #GVariantType
*
* Determines if the given @type is an array type. This is true if the
* type string for @type starts with an 'a'.
*
* This function returns %TRUE for any indefinite type for which every
* definite subtype is an array type -- %G_VARIANT_TYPE_ARRAY, for
* example.
*
* Returns: %TRUE if @type is an array type
*
* Since 2.24
**/
gboolean
g_variant_type_is_array (const GVariantType *type)
{
g_return_val_if_fail (g_variant_type_check (type), FALSE);
return g_variant_type_peek_string (type)[0] == 'a';
}
/**
* g_variant_type_is_tuple:
* @type: a #GVariantType
*
* Determines if the given @type is a tuple type. This is true if the
* type string for @type starts with a '(' or if @type is
* %G_VARIANT_TYPE_TUPLE.
*
* This function returns %TRUE for any indefinite type for which every
* definite subtype is a tuple type -- %G_VARIANT_TYPE_TUPLE, for
* example.
*
* Returns: %TRUE if @type is a tuple type
*
* Since 2.24
**/
gboolean
g_variant_type_is_tuple (const GVariantType *type)
{
gchar type_char;
g_return_val_if_fail (g_variant_type_check (type), FALSE);
type_char = g_variant_type_peek_string (type)[0];
return type_char == 'r' || type_char == '(';
}
/**
* g_variant_type_is_dict_entry:
* @type: a #GVariantType
*
* Determines if the given @type is a dictionary entry type. This is
* true if the type string for @type starts with a '{'.
*
* This function returns %TRUE for any indefinite type for which every
* definite subtype is a dictionary entry type --
* %G_VARIANT_TYPE_DICT_ENTRY, for example.
*
* Returns: %TRUE if @type is a dictionary entry type
*
* Since 2.24
**/
gboolean
g_variant_type_is_dict_entry (const GVariantType *type)
{
g_return_val_if_fail (g_variant_type_check (type), FALSE);
return g_variant_type_peek_string (type)[0] == '{';
}
/**
* g_variant_type_is_variant:
* @type: a #GVariantType
*
* Determines if the given @type is the variant type.
*
* Returns: %TRUE if @type is the variant type
*
* Since 2.24
**/
gboolean
g_variant_type_is_variant (const GVariantType *type)
{
g_return_val_if_fail (g_variant_type_check (type), FALSE);
return g_variant_type_peek_string (type)[0] == 'v';
}
/**
* g_variant_type_hash:
* @type: (type GVariantType): a #GVariantType
*
* Hashes @type.
*
* The argument type of @type is only #gconstpointer to allow use with
* #GHashTable without function pointer casting. A valid
* #GVariantType must be provided.
*
* Returns: the hash value
*
* Since 2.24
**/
guint
g_variant_type_hash (gconstpointer type)
{
const gchar *type_string;
guint value = 0;
gsize length;
gsize i;
g_return_val_if_fail (g_variant_type_check (type), 0);
type_string = g_variant_type_peek_string (type);
length = g_variant_type_get_string_length (type);
for (i = 0; i < length; i++)
value = (value << 5) - value + type_string[i];
return value;
}
/**
* g_variant_type_equal:
* @type1: (type GVariantType): a #GVariantType
* @type2: (type GVariantType): a #GVariantType
*
* Compares @type1 and @type2 for equality.
*
* Only returns %TRUE if the types are exactly equal. Even if one type
* is an indefinite type and the other is a subtype of it, %FALSE will
* be returned if they are not exactly equal. If you want to check for
* subtypes, use g_variant_type_is_subtype_of().
*
* The argument types of @type1 and @type2 are only #gconstpointer to
* allow use with #GHashTable without function pointer casting. For
* both arguments, a valid #GVariantType must be provided.
*
* Returns: %TRUE if @type1 and @type2 are exactly equal
*
* Since 2.24
**/
gboolean
g_variant_type_equal (gconstpointer type1,
gconstpointer type2)
{
const gchar *string1, *string2;
gsize size1, size2;
g_return_val_if_fail (g_variant_type_check (type1), FALSE);
g_return_val_if_fail (g_variant_type_check (type2), FALSE);
if (type1 == type2)
return TRUE;
size1 = g_variant_type_get_string_length (type1);
size2 = g_variant_type_get_string_length (type2);
if (size1 != size2)
return FALSE;
string1 = g_variant_type_peek_string (type1);
string2 = g_variant_type_peek_string (type2);
return memcmp (string1, string2, size1) == 0;
}
/**
* g_variant_type_is_subtype_of:
* @type: a #GVariantType
* @supertype: a #GVariantType
*
* Checks if @type is a subtype of @supertype.
*
* This function returns %TRUE if @type is a subtype of @supertype. All
* types are considered to be subtypes of themselves. Aside from that,
* only indefinite types can have subtypes.
*
* Returns: %TRUE if @type is a subtype of @supertype
*
* Since 2.24
**/
gboolean
g_variant_type_is_subtype_of (const GVariantType *type,
const GVariantType *supertype)
{
const gchar *supertype_string;
const gchar *supertype_end;
const gchar *type_string;
g_return_val_if_fail (g_variant_type_check (type), FALSE);
g_return_val_if_fail (g_variant_type_check (supertype), FALSE);
supertype_string = g_variant_type_peek_string (supertype);
type_string = g_variant_type_peek_string (type);
supertype_end = supertype_string +
g_variant_type_get_string_length (supertype);
/* we know that type and supertype are both well-formed, so it's
* safe to treat this merely as a text processing problem.
*/
while (supertype_string < supertype_end)
{
char supertype_char = *supertype_string++;
if (supertype_char == *type_string)
type_string++;
else if (*type_string == ')')
return FALSE;
else
{
const GVariantType *target_type = (GVariantType *) type_string;
switch (supertype_char)
{
case 'r':
if (!g_variant_type_is_tuple (target_type))
return FALSE;
break;
case '*':
break;
case '?':
if (!g_variant_type_is_basic (target_type))
return FALSE;
break;
default:
return FALSE;
}
type_string += g_variant_type_get_string_length (target_type);
}
}
return TRUE;
}
/**
* g_variant_type_element:
* @type: an array or maybe #GVariantType
*
* Determines the element type of an array or maybe type.
*
* This function may only be used with array or maybe types.
*
* Returns: (transfer none): the element type of @type
*
* Since 2.24
**/
const GVariantType *
g_variant_type_element (const GVariantType *type)
{
const gchar *type_string;
g_return_val_if_fail (g_variant_type_check (type), NULL);
type_string = g_variant_type_peek_string (type);
g_assert (type_string[0] == 'a' || type_string[0] == 'm');
return (const GVariantType *) &type_string[1];
}
/**
* g_variant_type_first:
* @type: a tuple or dictionary entry #GVariantType
*
* Determines the first item type of a tuple or dictionary entry
* type.
*
* This function may only be used with tuple or dictionary entry types,
* but must not be used with the generic tuple type
* %G_VARIANT_TYPE_TUPLE.
*
* In the case of a dictionary entry type, this returns the type of
* the key.
*
* %NULL is returned in case of @type being %G_VARIANT_TYPE_UNIT.
*
* This call, together with g_variant_type_next() provides an iterator
* interface over tuple and dictionary entry types.
*
* Returns: (transfer none): the first item type of @type, or %NULL
*
* Since 2.24
**/
const GVariantType *
g_variant_type_first (const GVariantType *type)
{
const gchar *type_string;
g_return_val_if_fail (g_variant_type_check (type), NULL);
type_string = g_variant_type_peek_string (type);
g_assert (type_string[0] == '(' || type_string[0] == '{');
if (type_string[1] == ')')
return NULL;
return (const GVariantType *) &type_string[1];
}
/**
* g_variant_type_next:
* @type: a #GVariantType from a previous call
*
* Determines the next item type of a tuple or dictionary entry
* type.
*
* @type must be the result of a previous call to
* g_variant_type_first() or g_variant_type_next().
*
* If called on the key type of a dictionary entry then this call
* returns the value type. If called on the value type of a dictionary
* entry then this call returns %NULL.
*
* For tuples, %NULL is returned when @type is the last item in a tuple.
*
* Returns: (transfer none): the next #GVariantType after @type, or %NULL
*
* Since 2.24
**/
const GVariantType *
g_variant_type_next (const GVariantType *type)
{
const gchar *type_string;
g_return_val_if_fail (g_variant_type_check (type), NULL);
type_string = g_variant_type_peek_string (type);
type_string += g_variant_type_get_string_length (type);
if (*type_string == ')' || *type_string == '}')
return NULL;
return (const GVariantType *) type_string;
}
/**
* g_variant_type_n_items:
* @type: a tuple or dictionary entry #GVariantType
*
* Determines the number of items contained in a tuple or
* dictionary entry type.
*
* This function may only be used with tuple or dictionary entry types,
* but must not be used with the generic tuple type
* %G_VARIANT_TYPE_TUPLE.
*
* In the case of a dictionary entry type, this function will always
* return 2.
*
* Returns: the number of items in @type
*
* Since 2.24
**/
gsize
g_variant_type_n_items (const GVariantType *type)
{
gsize count = 0;
g_return_val_if_fail (g_variant_type_check (type), 0);
for (type = g_variant_type_first (type);
type;
type = g_variant_type_next (type))
count++;
return count;
}
/**
* g_variant_type_key:
* @type: a dictionary entry #GVariantType
*
* Determines the key type of a dictionary entry type.
*
* This function may only be used with a dictionary entry type. Other
* than the additional restriction, this call is equivalent to
* g_variant_type_first().
*
* Returns: (transfer none): the key type of the dictionary entry
*
* Since 2.24
**/
const GVariantType *
g_variant_type_key (const GVariantType *type)
{
const gchar *type_string;
g_return_val_if_fail (g_variant_type_check (type), NULL);
type_string = g_variant_type_peek_string (type);
g_assert (type_string[0] == '{');
return (const GVariantType *) &type_string[1];
}
/**
* g_variant_type_value:
* @type: a dictionary entry #GVariantType
*
* Determines the value type of a dictionary entry type.
*
* This function may only be used with a dictionary entry type.
*
* Returns: (transfer none): the value type of the dictionary entry
*
* Since 2.24
**/
const GVariantType *
g_variant_type_value (const GVariantType *type)
{
#ifndef G_DISABLE_ASSERT
const gchar *type_string;
#endif
g_return_val_if_fail (g_variant_type_check (type), NULL);
#ifndef G_DISABLE_ASSERT
type_string = g_variant_type_peek_string (type);
g_assert (type_string[0] == '{');
#endif
return g_variant_type_next (g_variant_type_key (type));
}
/**
* g_variant_type_new_tuple:
* @items: (array length=length): an array of #GVariantTypes, one for each item
* @length: the length of @items, or -1
*
* Constructs a new tuple type, from @items.
*
* @length is the number of items in @items, or -1 to indicate that
* @items is %NULL-terminated.
*
* It is appropriate to call g_variant_type_free() on the return value.
*
* Returns: (transfer full): a new tuple #GVariantType
*
* Since 2.24
**/
static GVariantType *
g_variant_type_new_tuple_slow (const GVariantType * const *items,
gint length)
{
/* the "slow" version is needed in case the static buffer of 1024
* bytes is exceeded when running the normal version. this will
* happen only with very unusually large types, so it can be slow.
*/
GString *string;
gint i;
string = g_string_new ("(");
for (i = 0; i < length; i++)
{
const GVariantType *type;
gsize size;
g_return_val_if_fail (g_variant_type_check (items[i]), NULL);
type = items[i];
size = g_variant_type_get_string_length (type);
g_string_append_len (string, (const gchar *) type, size);
}
g_string_append_c (string, ')');
return (GVariantType *) g_string_free (string, FALSE);
}
GVariantType *
g_variant_type_new_tuple (const GVariantType * const *items,
gint length)
{
char buffer[1024];
gsize offset;
gsize i;
gsize length_unsigned;
g_return_val_if_fail (length == 0 || items != NULL, NULL);
if (length < 0)
for (length_unsigned = 0; items[length_unsigned] != NULL; length_unsigned++);
else
length_unsigned = (gsize) length;
offset = 0;
buffer[offset++] = '(';
for (i = 0; i < length_unsigned; i++)
{
const GVariantType *type;
gsize size;
g_return_val_if_fail (g_variant_type_check (items[i]), NULL);
type = items[i];
size = g_variant_type_get_string_length (type);
if (offset + size >= sizeof buffer) /* leave room for ')' */
return g_variant_type_new_tuple_slow (items, length_unsigned);
memcpy (&buffer[offset], type, size);
offset += size;
}
g_assert (offset < sizeof buffer);
buffer[offset++] = ')';
return (GVariantType *) g_memdup2 (buffer, offset);
}
/**
* g_variant_type_new_array: (constructor)
* @element: a #GVariantType
*
* Constructs the type corresponding to an array of elements of the
* type @type.
*
* It is appropriate to call g_variant_type_free() on the return value.
*
* Returns: (transfer full): a new array #GVariantType
*
* Since 2.24
**/
GVariantType *
g_variant_type_new_array (const GVariantType *element)
{
gsize size;
gchar *new;
g_return_val_if_fail (g_variant_type_check (element), NULL);
size = g_variant_type_get_string_length (element);
new = g_malloc (size + 1);
new[0] = 'a';
memcpy (new + 1, element, size);
return (GVariantType *) new;
}
/**
* g_variant_type_new_maybe: (constructor)
* @element: a #GVariantType
*
* Constructs the type corresponding to a maybe instance containing
* type @type or Nothing.
*
* It is appropriate to call g_variant_type_free() on the return value.
*
* Returns: (transfer full): a new maybe #GVariantType
*
* Since 2.24
**/
GVariantType *
g_variant_type_new_maybe (const GVariantType *element)
{
gsize size;
gchar *new;
g_return_val_if_fail (g_variant_type_check (element), NULL);
size = g_variant_type_get_string_length (element);
new = g_malloc (size + 1);
new[0] = 'm';
memcpy (new + 1, element, size);
return (GVariantType *) new;
}
/**
* g_variant_type_new_dict_entry: (constructor)
* @key: a basic #GVariantType
* @value: a #GVariantType
*
* Constructs the type corresponding to a dictionary entry with a key
* of type @key and a value of type @value.
*
* It is appropriate to call g_variant_type_free() on the return value.
*
* Returns: (transfer full): a new dictionary entry #GVariantType
*
* Since 2.24
**/
GVariantType *
g_variant_type_new_dict_entry (const GVariantType *key,
const GVariantType *value)
{
gsize keysize, valsize;
gchar *new;
g_return_val_if_fail (g_variant_type_check (key), NULL);
g_return_val_if_fail (g_variant_type_check (value), NULL);
keysize = g_variant_type_get_string_length (key);
valsize = g_variant_type_get_string_length (value);
new = g_malloc (1 + keysize + valsize + 1);
new[0] = '{';
memcpy (new + 1, key, keysize);
memcpy (new + 1 + keysize, value, valsize);
new[1 + keysize + valsize] = '}';
return (GVariantType *) new;
}
/* private */
const GVariantType *
g_variant_type_checked_ (const gchar *type_string)
{
g_return_val_if_fail (g_variant_type_string_is_valid (type_string), NULL);
return (const GVariantType *) type_string;
}
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