2 * Copyright © 2007, 2008 Ryan Lortie
3 * Copyright © 2009, 2010 Codethink Limited
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the licence, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
20 * Author: Ryan Lortie <desrt@desrt.ca>
23 #include "gvarianttype.h"
25 #include <glib/gtestutils.h>
32 * SECTION: gvarianttype
33 * @title: GVariantType
34 * @short_description: introduction to the GVariant type system
35 * @see_also: #GVariantType, #GVariant
37 * This section introduces the GVariant type system. It is based, in
38 * large part, on the DBus type system, with two major changes and some minor
39 * lifting of restrictions. The <ulink
40 * url='http://dbus.freedesktop.org/doc/dbus-specification.html'>DBus
41 * specification</ulink>, therefore, provides a significant amount of
42 * information that is useful when working with GVariant.
44 * The first major change with respect to the DBus type system is the
45 * introduction of maybe (or "nullable") types. Any type in GVariant can be
46 * converted to a maybe type, in which case, "nothing" (or "null") becomes a
47 * valid value. Maybe types have been added by introducing the
48 * character "<literal>m</literal>" to type strings.
50 * The second major change is that the GVariant type system supports the
51 * concept of "indefinite types" -- types that are less specific than
52 * the normal types found in DBus. For example, it is possible to speak
53 * of "an array of any type" in GVariant, where the DBus type system
54 * would require you to speak of "an array of integers" or "an array of
55 * strings". Indefinite types have been added by introducing the
56 * characters "<literal>*</literal>", "<literal>?</literal>" and
57 * "<literal>r</literal>" to type strings.
59 * Finally, all arbitrary restrictions relating to the complexity of
60 * types are lifted along with the restriction that dictionary entries
61 * may only appear nested inside of arrays.
63 * Just as in DBus, GVariant types are described with strings ("type
64 * strings"). Subject to the differences mentioned above, these strings
65 * are of the same form as those found in DBus. Note, however: DBus
66 * always works in terms of messages and therefore individual type
67 * strings appear nowhere in its interface. Instead, "signatures"
68 * are a concatenation of the strings of the type of each argument in a
69 * message. GVariant deals with single values directly so GVariant type
70 * strings always describe the type of exactly one value. This means
71 * that a DBus signature string is generally not a valid GVariant type
72 * string -- except in the case that it is the signature of a message
73 * containing exactly one argument.
75 * An indefinite type is similar in spirit to what may be called an
76 * abstract type in other type systems. No value can exist that has an
77 * indefinite type as its type, but values can exist that have types
78 * that are subtypes of indefinite types. That is to say,
79 * g_variant_get_type() will never return an indefinite type, but
80 * calling g_variant_is_a() with an indefinite type may return %TRUE.
81 * For example, you can not have a value that represents "an array of no
82 * particular type", but you can have an "array of integers" which
83 * certainly matches the type of "an array of no particular type", since
84 * "array of integers" is a subtype of "array of no particular type".
86 * This is similar to how instances of abstract classes may not
87 * directly exist in other type systems, but instances of their
88 * non-abstract subtypes may. For example, in GTK, no object that has
89 * the type of #GtkBin can exist (since #GtkBin is an abstract class),
90 * but a #GtkWindow can certainly be instantiated, and you would say
91 * that the #GtkWindow is a #GtkBin (since #GtkWindow is a subclass of
94 * A detailed description of GVariant type strings is given here:
96 * <refsect2 id='gvariant-typestrings'>
97 * <title>GVariant Type Strings</title>
99 * A GVariant type string can be any of the following:
104 * any basic type string (listed below)
109 * "<literal>v</literal>", "<literal>r</literal>" or
110 * "<literal>*</literal>"
115 * one of the characters '<literal>a</literal>' or
116 * '<literal>m</literal>', followed by another type string
121 * the character '<literal>(</literal>', followed by a concatenation
122 * of zero or more other type strings, followed by the character
123 * '<literal>)</literal>'
128 * the character '<literal>{</literal>', followed by a basic type
129 * string (see below), followed by another type string, followed by
130 * the character '<literal>}</literal>'
135 * A basic type string describes a basic type (as per
136 * g_variant_type_is_basic()) and is always a single
137 * character in length. The valid basic type strings are
138 * "<literal>b</literal>", "<literal>y</literal>",
139 * "<literal>n</literal>", "<literal>q</literal>",
140 * "<literal>i</literal>", "<literal>u</literal>",
141 * "<literal>x</literal>", "<literal>t</literal>",
142 * "<literal>h</literal>", "<literal>d</literal>",
143 * "<literal>s</literal>", "<literal>o</literal>",
144 * "<literal>g</literal>" and "<literal>?</literal>".
147 * The above definition is recursive to arbitrary depth.
148 * "<literal>aaaaai</literal>" and "<literal>(ui(nq((y)))s)</literal>"
149 * are both valid type strings, as is
150 * "<literal>a(aa(ui)(qna{ya(yd)}))</literal>".
153 * The meaning of each of the characters is as follows:
161 * <emphasis role='strong'>Character</emphasis>
166 * <emphasis role='strong'>Meaning</emphasis>
173 * <literal>b</literal>
178 * the type string of %G_VARIANT_TYPE_BOOLEAN; a boolean value.
185 * <literal>y</literal>
190 * the type string of %G_VARIANT_TYPE_BYTE; a byte.
197 * <literal>n</literal>
202 * the type string of %G_VARIANT_TYPE_INT16; a signed 16 bit
210 * <literal>q</literal>
215 * the type string of %G_VARIANT_TYPE_UINT16; an unsigned 16 bit
223 * <literal>i</literal>
228 * the type string of %G_VARIANT_TYPE_INT32; a signed 32 bit
236 * <literal>u</literal>
241 * the type string of %G_VARIANT_TYPE_UINT32; an unsigned 32 bit
249 * <literal>x</literal>
254 * the type string of %G_VARIANT_TYPE_INT64; a signed 64 bit
262 * <literal>t</literal>
267 * the type string of %G_VARIANT_TYPE_UINT64; an unsigned 64 bit
275 * <literal>h</literal>
280 * the type string of %G_VARIANT_TYPE_HANDLE; a signed 32 bit
281 * value that, by convention, is used as an index into an array
282 * of file descriptors that are sent alongside a DBus message.
289 * <literal>d</literal>
294 * the type string of %G_VARIANT_TYPE_DOUBLE; a double precision
295 * floating point value.
302 * <literal>s</literal>
307 * the type string of %G_VARIANT_TYPE_STRING; a string.
314 * <literal>o</literal>
319 * the type string of %G_VARIANT_TYPE_OBJECT_PATH; a string in
320 * the form of a DBus object path.
327 * <literal>g</literal>
332 * the type string of %G_VARIANT_TYPE_STRING; a string in the
333 * form of a DBus type signature.
340 * <literal>?</literal>
345 * the type string of %G_VARIANT_TYPE_BASIC; an indefinite type
346 * that is a supertype of any of the basic types.
353 * <literal>v</literal>
358 * the type string of %G_VARIANT_TYPE_VARIANT; a container type
359 * that contain any other type of value.
366 * <literal>a</literal>
371 * used as a prefix on another type string to mean an array of
372 * that type; the type string "<literal>ai</literal>", for
373 * example, is the type of an array of 32 bit signed integers.
380 * <literal>m</literal>
385 * used as a prefix on another type string to mean a "maybe", or
386 * "nullable", version of that type; the type string
387 * "<literal>ms</literal>", for example, is the type of a value
388 * that maybe contains a string, or maybe contains nothing.
395 * <literal>()</literal>
400 * used to enclose zero or more other concatenated type strings
401 * to create a tuple type; the type string
402 * "<literal>(is)</literal>", for example, is the type of a pair
403 * of an integer and a string.
410 * <literal>r</literal>
415 * the type string of %G_VARIANT_TYPE_TUPLE; an indefinite type
416 * that is a supertype of any tuple type, regardless of the
424 * <literal>{}</literal>
429 * used to enclose a basic type string concatenated with another
430 * type string to create a dictionary entry type, which usually
431 * appears inside of an array to form a dictionary; the type
432 * string "<literal>a{sd}</literal>", for example, is the type of
433 * a dictionary that maps strings to double precision floating
437 * The first type (the basic type) is the key type and the second
438 * type is the value type. The reason that the first type is
439 * restricted to being a basic type is so that it can easily be
447 * <literal>*</literal>
452 * the type string of %G_VARIANT_TYPE_ANY; the indefinite type
453 * that is a supertype of all types. Note that, as with all type
454 * strings, this character represents exactly one type. It
455 * cannot be used inside of tuples to mean "any number of items".
463 * Any type string of a container that contains an indefinite type is,
464 * itself, an indefinite type. For example, the type string
465 * "<literal>a*</literal>" (corresponding to %G_VARIANT_TYPE_ARRAY) is
466 * an indefinite type that is a supertype of every array type.
467 * "<literal>(*s)</literal>" is a supertype of all tuples that
468 * contain exactly two items where the second item is a string.
471 * "<literal>a{?*}</literal>" is an indefinite type that is a
472 * supertype of all arrays containing dictionary entries where the key
473 * is any basic type and the value is any type at all. This is, by
474 * definition, a dictionary, so this type string corresponds to
475 * %G_VARIANT_TYPE_DICTIONARY. Note that, due to the restriction that
476 * the key of a dictionary entry must be a basic type,
477 * "<literal>{**}</literal>" is not a valid type string.
484 g_variant_type_check (const GVariantType *type)
486 const gchar *type_string;
491 type_string = (const gchar *) type;
492 #ifndef G_DISABLE_CHECKS
493 return g_variant_type_string_scan (type_string, NULL, NULL);
500 * g_variant_type_string_scan:
501 * @string: a pointer to any string
502 * @limit: the end of @string, or %NULL
503 * @endptr: location to store the end pointer, or %NULL
504 * @returns: %TRUE if a valid type string was found
506 * Scan for a single complete and valid GVariant type string in @string.
507 * The memory pointed to by @limit (or bytes beyond it) is never
510 * If a valid type string is found, @endptr is updated to point to the
511 * first character past the end of the string that was found and %TRUE
514 * If there is no valid type string starting at @string, or if the type
515 * string does not end before @limit then %FALSE is returned.
517 * For the simple case of checking if a string is a valid type string,
518 * see g_variant_type_string_is_valid().
523 g_variant_type_string_scan (const gchar *string,
525 const gchar **endptr)
527 g_return_val_if_fail (string != NULL, FALSE);
529 if (string == limit || *string == '\0')
535 while (string == limit || *string != ')')
536 if (!g_variant_type_string_scan (string, limit, &string))
543 if (string == limit || *string == '\0' || /* { */
544 !strchr ("bynqihuxtdsog?", *string++) || /* key */
545 !g_variant_type_string_scan (string, limit, &string) || /* value */
546 string == limit || *string++ != '}') /* } */
552 return g_variant_type_string_scan (string, limit, endptr);
554 case 'b': case 'y': case 'n': case 'q': case 'i': case 'u':
555 case 'x': case 't': case 'd': case 's': case 'o': case 'g':
556 case 'v': case 'r': case '*': case '?': case 'h':
570 * g_variant_type_string_is_valid:
571 * @type_string: a pointer to any string
572 * @returns: %TRUE if @type_string is exactly one valid type string
574 * Checks if @type_string is a valid GVariant type string. This call is
575 * equivalent to calling g_variant_type_string_scan() and confirming
576 * that the following character is a nul terminator.
581 g_variant_type_string_is_valid (const gchar *type_string)
585 g_return_val_if_fail (type_string != NULL, FALSE);
587 if (!g_variant_type_string_scan (type_string, NULL, &endptr))
590 return *endptr == '\0';
594 * g_variant_type_free:
595 * @type: a #GVariantType, or %NULL
597 * Frees a #GVariantType that was allocated with
598 * g_variant_type_copy(), g_variant_type_new() or one of the container
599 * type constructor functions.
601 * In the case that @type is %NULL, this function does nothing.
606 g_variant_type_free (GVariantType *type)
608 g_return_if_fail (type == NULL || g_variant_type_check (type));
614 * g_variant_type_copy:
615 * @type: a #GVariantType
616 * @returns: a new #GVariantType
618 * Makes a copy of a #GVariantType. It is appropriate to call
619 * g_variant_type_free() on the return value. @type may not be %NULL.
624 g_variant_type_copy (const GVariantType *type)
629 g_return_val_if_fail (g_variant_type_check (type), NULL);
631 length = g_variant_type_get_string_length (type);
632 new = g_malloc (length + 1);
634 memcpy (new, type, length);
637 return (GVariantType *) new;
641 * g_variant_type_new:
642 * @type_string: a valid GVariant type string
643 * @returns: a new #GVariantType
645 * Creates a new #GVariantType corresponding to the type string given
646 * by @type_string. It is appropriate to call g_variant_type_free() on
649 * It is a programmer error to call this function with an invalid type
650 * string. Use g_variant_type_string_is_valid() if you are unsure.
655 g_variant_type_new (const gchar *type_string)
657 g_return_val_if_fail (type_string != NULL, NULL);
659 return g_variant_type_copy (G_VARIANT_TYPE (type_string));
663 * g_variant_type_get_string_length:
664 * @type: a #GVariantType
665 * @returns: the length of the corresponding type string
667 * Returns the length of the type string corresponding to the given
668 * @type. This function must be used to determine the valid extent of
669 * the memory region returned by g_variant_type_peek_string().
674 g_variant_type_get_string_length (const GVariantType *type)
676 const gchar *type_string = (const gchar *) type;
680 g_return_val_if_fail (g_variant_type_check (type), 0);
684 while (type_string[index] == 'a' || type_string[index] == 'm')
687 if (type_string[index] == '(' || type_string[index] == '{')
690 else if (type_string[index] == ')' || type_string[index] == '}')
701 * g_variant_type_peek_string:
702 * @type: a #GVariantType
703 * @returns: the corresponding type string (not nul-terminated)
705 * Returns the type string corresponding to the given @type. The
706 * result is not nul-terminated; in order to determine its length you
707 * must call g_variant_type_get_string_length().
709 * To get a nul-terminated string, see g_variant_type_dup_string().
714 g_variant_type_peek_string (const GVariantType *type)
716 g_return_val_if_fail (g_variant_type_check (type), NULL);
718 return (const gchar *) type;
722 * g_variant_type_dup_string:
723 * @type: a #GVariantType
724 * @returns: the corresponding type string
726 * Returns a newly-allocated copy of the type string corresponding to
727 * @type. The returned string is nul-terminated. It is appropriate to
728 * call g_free() on the return value.
733 g_variant_type_dup_string (const GVariantType *type)
735 g_return_val_if_fail (g_variant_type_check (type), NULL);
737 return g_strndup (g_variant_type_peek_string (type),
738 g_variant_type_get_string_length (type));
742 * g_variant_type_is_definite:
743 * @type: a #GVariantType
744 * @returns: %TRUE if @type is definite
746 * Determines if the given @type is definite (ie: not indefinite).
748 * A type is definite if its type string does not contain any indefinite
749 * type characters ('*', '?', or 'r').
751 * A #GVariant instance may not have an indefinite type, so calling
752 * this function on the result of g_variant_get_type() will always
753 * result in %TRUE being returned. Calling this function on an
754 * indefinite type like %G_VARIANT_TYPE_ARRAY, however, will result in
755 * %FALSE being returned.
760 g_variant_type_is_definite (const GVariantType *type)
762 const gchar *type_string;
766 g_return_val_if_fail (g_variant_type_check (type), FALSE);
768 type_length = g_variant_type_get_string_length (type);
769 type_string = g_variant_type_peek_string (type);
771 for (i = 0; i < type_length; i++)
772 if (type_string[i] == '*' ||
773 type_string[i] == '?' ||
774 type_string[i] == 'r')
781 * g_variant_type_is_container:
782 * @type: a #GVariantType
783 * @returns: %TRUE if @type is a container type
785 * Determines if the given @type is a container type.
787 * Container types are any array, maybe, tuple, or dictionary
788 * entry types plus the variant type.
790 * This function returns %TRUE for any indefinite type for which every
791 * definite subtype is a container -- %G_VARIANT_TYPE_ARRAY, for
797 g_variant_type_is_container (const GVariantType *type)
801 g_return_val_if_fail (g_variant_type_check (type), FALSE);
803 first_char = g_variant_type_peek_string (type)[0];
820 * g_variant_type_is_basic:
821 * @type: a #GVariantType
822 * @returns: %TRUE if @type is a basic type
824 * Determines if the given @type is a basic type.
826 * Basic types are booleans, bytes, integers, doubles, strings, object
827 * paths and signatures.
829 * Only a basic type may be used as the key of a dictionary entry.
831 * This function returns %FALSE for all indefinite types except
832 * %G_VARIANT_TYPE_BASIC.
837 g_variant_type_is_basic (const GVariantType *type)
841 g_return_val_if_fail (g_variant_type_check (type), FALSE);
843 first_char = g_variant_type_peek_string (type)[0];
868 * g_variant_type_is_maybe:
869 * @type: a #GVariantType
870 * @returns: %TRUE if @type is a maybe type
872 * Determines if the given @type is a maybe type. This is true if the
873 * type string for @type starts with an 'm'.
875 * This function returns %TRUE for any indefinite type for which every
876 * definite subtype is a maybe type -- %G_VARIANT_TYPE_MAYBE, for
882 g_variant_type_is_maybe (const GVariantType *type)
884 g_return_val_if_fail (g_variant_type_check (type), FALSE);
886 return g_variant_type_peek_string (type)[0] == 'm';
890 * g_variant_type_is_array:
891 * @type: a #GVariantType
892 * @returns: %TRUE if @type is an array type
894 * Determines if the given @type is an array type. This is true if the
895 * type string for @type starts with an 'a'.
897 * This function returns %TRUE for any indefinite type for which every
898 * definite subtype is an array type -- %G_VARIANT_TYPE_ARRAY, for
904 g_variant_type_is_array (const GVariantType *type)
906 g_return_val_if_fail (g_variant_type_check (type), FALSE);
908 return g_variant_type_peek_string (type)[0] == 'a';
912 * g_variant_type_is_tuple:
913 * @type: a #GVariantType
914 * @returns: %TRUE if @type is a tuple type
916 * Determines if the given @type is a tuple type. This is true if the
917 * type string for @type starts with a '(' or if @type is
918 * %G_VARIANT_TYPE_TUPLE.
920 * This function returns %TRUE for any indefinite type for which every
921 * definite subtype is a tuple type -- %G_VARIANT_TYPE_TUPLE, for
927 g_variant_type_is_tuple (const GVariantType *type)
931 g_return_val_if_fail (g_variant_type_check (type), FALSE);
933 type_char = g_variant_type_peek_string (type)[0];
934 return type_char == 'r' || type_char == '(';
938 * g_variant_type_is_dict_entry:
939 * @type: a #GVariantType
940 * @returns: %TRUE if @type is a dictionary entry type
942 * Determines if the given @type is a dictionary entry type. This is
943 * true if the type string for @type starts with a '{'.
945 * This function returns %TRUE for any indefinite type for which every
946 * definite subtype is a dictionary entry type --
947 * %G_VARIANT_TYPE_DICT_ENTRY, for example.
952 g_variant_type_is_dict_entry (const GVariantType *type)
954 g_return_val_if_fail (g_variant_type_check (type), FALSE);
956 return g_variant_type_peek_string (type)[0] == '{';
960 * g_variant_type_hash:
961 * @type: a #GVariantType
962 * @returns: the hash value
966 * The argument type of @type is only #gconstpointer to allow use with
967 * #GHashTable without function pointer casting. A valid
968 * #GVariantType must be provided.
973 g_variant_type_hash (gconstpointer type)
975 const gchar *type_string;
980 g_return_val_if_fail (g_variant_type_check (type), 0);
982 type_string = g_variant_type_peek_string (type);
983 length = g_variant_type_get_string_length (type);
985 for (i = 0; i < length; i++)
986 value = (value << 5) - value + type_string[i];
992 * g_variant_type_equal:
993 * @type1: a #GVariantType
994 * @type2: a #GVariantType
995 * @returns: %TRUE if @type1 and @type2 are exactly equal
997 * Compares @type1 and @type2 for equality.
999 * Only returns %TRUE if the types are exactly equal. Even if one type
1000 * is an indefinite type and the other is a subtype of it, %FALSE will
1001 * be returned if they are not exactly equal. If you want to check for
1002 * subtypes, use g_variant_type_is_subtype_of().
1004 * The argument types of @type1 and @type2 are only #gconstpointer to
1005 * allow use with #GHashTable without function pointer casting. For
1006 * both arguments, a valid #GVariantType must be provided.
1011 g_variant_type_equal (gconstpointer type1,
1012 gconstpointer type2)
1014 const gchar *string1, *string2;
1017 g_return_val_if_fail (g_variant_type_check (type1), FALSE);
1018 g_return_val_if_fail (g_variant_type_check (type2), FALSE);
1023 size1 = g_variant_type_get_string_length (type1);
1024 size2 = g_variant_type_get_string_length (type2);
1029 string1 = g_variant_type_peek_string (type1);
1030 string2 = g_variant_type_peek_string (type2);
1032 return memcmp (string1, string2, size1) == 0;
1036 * g_variant_type_is_subtype_of:
1037 * @type: a #GVariantType
1038 * @supertype: a #GVariantType
1039 * @returns: %TRUE if @type is a subtype of @supertype
1041 * Checks if @type is a subtype of @supertype.
1043 * This function returns %TRUE if @type is a subtype of @supertype. All
1044 * types are considered to be subtypes of themselves. Aside from that,
1045 * only indefinite types can have subtypes.
1050 g_variant_type_is_subtype_of (const GVariantType *type,
1051 const GVariantType *supertype)
1053 const gchar *supertype_string;
1054 const gchar *supertype_end;
1055 const gchar *type_string;
1057 g_return_val_if_fail (g_variant_type_check (type), FALSE);
1058 g_return_val_if_fail (g_variant_type_check (supertype), FALSE);
1060 supertype_string = g_variant_type_peek_string (supertype);
1061 type_string = g_variant_type_peek_string (type);
1063 supertype_end = supertype_string +
1064 g_variant_type_get_string_length (supertype);
1066 /* we know that type and supertype are both well-formed, so it's
1067 * safe to treat this merely as a text processing problem.
1069 while (supertype_string < supertype_end)
1071 char supertype_char = *supertype_string++;
1073 if (supertype_char == *type_string)
1076 else if (*type_string == ')')
1081 const GVariantType *target_type = (GVariantType *) type_string;
1083 switch (supertype_char)
1086 if (!g_variant_type_is_tuple (target_type))
1094 if (!g_variant_type_is_basic (target_type))
1102 type_string += g_variant_type_get_string_length (target_type);
1110 * g_variant_type_element:
1111 * @type: an array or maybe #GVariantType
1112 * @returns: the element type of @type
1114 * Determines the element type of an array or maybe type.
1116 * This function may only be used with array or maybe types.
1120 const GVariantType *
1121 g_variant_type_element (const GVariantType *type)
1123 const gchar *type_string;
1125 g_return_val_if_fail (g_variant_type_check (type), NULL);
1127 type_string = g_variant_type_peek_string (type);
1129 g_assert (type_string[0] == 'a' || type_string[0] == 'm');
1131 return (const GVariantType *) &type_string[1];
1135 * g_variant_type_first:
1136 * @type: a tuple or dictionary entry #GVariantType
1137 * @returns: the first item type of @type, or %NULL
1139 * Determines the first item type of a tuple or dictionary entry
1142 * This function may only be used with tuple or dictionary entry types,
1143 * but must not be used with the generic tuple type
1144 * %G_VARIANT_TYPE_TUPLE.
1146 * In the case of a dictionary entry type, this returns the type of
1149 * %NULL is returned in case of @type being %G_VARIANT_TYPE_UNIT.
1151 * This call, together with g_variant_type_next() provides an iterator
1152 * interface over tuple and dictionary entry types.
1156 const GVariantType *
1157 g_variant_type_first (const GVariantType *type)
1159 const gchar *type_string;
1161 g_return_val_if_fail (g_variant_type_check (type), NULL);
1163 type_string = g_variant_type_peek_string (type);
1164 g_assert (type_string[0] == '(' || type_string[0] == '{');
1166 if (type_string[1] == ')')
1169 return (const GVariantType *) &type_string[1];
1173 * g_variant_type_next:
1174 * @type: a #GVariantType from a previous call
1175 * @returns: the next #GVariantType after @type, or %NULL
1177 * Determines the next item type of a tuple or dictionary entry
1180 * @type must be the result of a previous call to
1181 * g_variant_type_first() or g_variant_type_next().
1183 * If called on the key type of a dictionary entry then this call
1184 * returns the value type. If called on the value type of a dictionary
1185 * entry then this call returns %NULL.
1187 * For tuples, %NULL is returned when @type is the last item in a tuple.
1191 const GVariantType *
1192 g_variant_type_next (const GVariantType *type)
1194 const gchar *type_string;
1196 g_return_val_if_fail (g_variant_type_check (type), NULL);
1198 type_string = g_variant_type_peek_string (type);
1199 type_string += g_variant_type_get_string_length (type);
1201 if (*type_string == ')' || *type_string == '}')
1204 return (const GVariantType *) type_string;
1208 * g_variant_type_n_items:
1209 * @type: a tuple or dictionary entry #GVariantType
1210 * @returns: the number of items in @type
1212 * Determines the number of items contained in a tuple or
1213 * dictionary entry type.
1215 * This function may only be used with tuple or dictionary entry types,
1216 * but must not be used with the generic tuple type
1217 * %G_VARIANT_TYPE_TUPLE.
1219 * In the case of a dictionary entry type, this function will always
1225 g_variant_type_n_items (const GVariantType *type)
1229 g_return_val_if_fail (g_variant_type_check (type), 0);
1231 for (type = g_variant_type_first (type);
1233 type = g_variant_type_next (type))
1240 * g_variant_type_key:
1241 * @type: a dictionary entry #GVariantType
1242 * @returns: the key type of the dictionary entry
1244 * Determines the key type of a dictionary entry type.
1246 * This function may only be used with a dictionary entry type. Other
1247 * than the additional restriction, this call is equivalent to
1248 * g_variant_type_first().
1252 const GVariantType *
1253 g_variant_type_key (const GVariantType *type)
1255 const gchar *type_string;
1257 g_return_val_if_fail (g_variant_type_check (type), NULL);
1259 type_string = g_variant_type_peek_string (type);
1260 g_assert (type_string[0] == '{');
1262 return (const GVariantType *) &type_string[1];
1266 * g_variant_type_value:
1267 * @type: a dictionary entry #GVariantType
1268 * @returns: the value type of the dictionary entry
1270 * Determines the value type of a dictionary entry type.
1272 * This function may only be used with a dictionary entry type.
1276 const GVariantType *
1277 g_variant_type_value (const GVariantType *type)
1279 const gchar *type_string;
1281 g_return_val_if_fail (g_variant_type_check (type), NULL);
1283 type_string = g_variant_type_peek_string (type);
1284 g_assert (type_string[0] == '{');
1286 return g_variant_type_next (g_variant_type_key (type));
1290 * g_variant_type_new_tuple:
1291 * @items: an array of #GVariantTypes, one for each item
1292 * @length: the length of @items, or -1
1293 * @returns: a new tuple #GVariantType
1295 * Constructs a new tuple type, from @items.
1297 * @length is the number of items in @items, or -1 to indicate that
1298 * @items is %NULL-terminated.
1300 * It is appropriate to call g_variant_type_free() on the return value.
1304 static GVariantType *
1305 g_variant_type_new_tuple_slow (const GVariantType * const *items,
1308 /* the "slow" version is needed in case the static buffer of 1024
1309 * bytes is exceeded when running the normal version. this will
1310 * happen only in truly insane code, so it can be slow.
1315 string = g_string_new ("(");
1316 for (i = 0; i < length; i++)
1318 const GVariantType *type;
1321 g_return_val_if_fail (g_variant_type_check (items[i]), NULL);
1324 size = g_variant_type_get_string_length (type);
1325 g_string_append_len (string, (const gchar *) type, size);
1327 g_string_append_c (string, ')');
1329 return (GVariantType *) g_string_free (string, FALSE);
1333 g_variant_type_new_tuple (const GVariantType * const *items,
1340 g_return_val_if_fail (length == 0 || items != NULL, NULL);
1343 for (length = 0; items[length] != NULL; length++);
1346 buffer[offset++] = '(';
1348 for (i = 0; i < length; i++)
1350 const GVariantType *type;
1353 g_return_val_if_fail (g_variant_type_check (items[i]), NULL);
1356 size = g_variant_type_get_string_length (type);
1358 if (offset + size >= sizeof buffer) /* leave room for ')' */
1359 return g_variant_type_new_tuple_slow (items, length);
1361 memcpy (&buffer[offset], type, size);
1365 g_assert (offset < sizeof buffer);
1366 buffer[offset++] = ')';
1368 return (GVariantType *) g_memdup (buffer, offset);
1372 * g_variant_type_new_array:
1373 * @element: a #GVariantType
1374 * @returns: a new array #GVariantType
1376 * Constructs the type corresponding to an array of elements of the
1379 * It is appropriate to call g_variant_type_free() on the return value.
1384 g_variant_type_new_array (const GVariantType *element)
1389 g_return_val_if_fail (g_variant_type_check (element), NULL);
1391 size = g_variant_type_get_string_length (element);
1392 new = g_malloc (size + 1);
1395 memcpy (new + 1, element, size);
1397 return (GVariantType *) new;
1401 * g_variant_type_new_maybe:
1402 * @element: a #GVariantType
1403 * @returns: a new maybe #GVariantType
1405 * Constructs the type corresponding to a maybe instance containing
1406 * type @type or Nothing.
1408 * It is appropriate to call g_variant_type_free() on the return value.
1413 g_variant_type_new_maybe (const GVariantType *element)
1418 g_return_val_if_fail (g_variant_type_check (element), NULL);
1420 size = g_variant_type_get_string_length (element);
1421 new = g_malloc (size + 1);
1424 memcpy (new + 1, element, size);
1426 return (GVariantType *) new;
1430 * g_variant_type_new_dict_entry:
1431 * @key: a basic #GVariantType
1432 * @value: a #GVariantType
1433 * @returns: a new dictionary entry #GVariantType
1435 * Constructs the type corresponding to a dictionary entry with a key
1436 * of type @key and a value of type @value.
1438 * It is appropriate to call g_variant_type_free() on the return value.
1443 g_variant_type_new_dict_entry (const GVariantType *key,
1444 const GVariantType *value)
1446 gsize keysize, valsize;
1449 g_return_val_if_fail (g_variant_type_check (key), NULL);
1450 g_return_val_if_fail (g_variant_type_check (value), NULL);
1452 keysize = g_variant_type_get_string_length (key);
1453 valsize = g_variant_type_get_string_length (value);
1455 new = g_malloc (1 + keysize + valsize + 1);
1458 memcpy (new + 1, key, keysize);
1459 memcpy (new + 1 + keysize, value, valsize);
1460 new[1 + keysize + valsize] = '}';
1462 return (GVariantType *) new;
1466 const GVariantType *
1467 g_variant_type_checked_ (const gchar *type_string)
1469 g_return_val_if_fail (g_variant_type_string_is_valid (type_string), NULL);
1470 return (const GVariantType *) type_string;
1473 #define __G_VARIANT_TYPE_C__
1474 #include "galiasdef.c"
projects / platform / upstream / glib.git / blob