1 /*
2 * Copyright © 2007, 2008 Ryan Lortie
3 * Copyright © 2010 Codethink Limited
4 *
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.
9 *
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.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 *
18 * Author: Ryan Lortie <desrt@desrt.ca>
19 */
20
21 /* Prologue {{{1 */
22
23 #include "config.h"
24
25 #include <glib/gvariant-serialiser.h>
26 #include "gvariant-internal.h"
27 #include <glib/gvariant-core.h>
28 #include <glib/gtestutils.h>
29 #include <glib/gstrfuncs.h>
30 #include <glib/gslice.h>
31 #include <glib/ghash.h>
32 #include <glib/gmem.h>
33
34 #include <string.h>
35
36
37 /**
38 * SECTION:gvariant
39 * @title: GVariant
40 * @short_description: strongly typed value datatype
41 * @see_also: GVariantType
42 *
43 * #GVariant is a variant datatype; it stores a value along with
44 * information about the type of that value. The range of possible
45 * values is determined by the type. The type system used by #GVariant
46 * is #GVariantType.
47 *
48 * #GVariant instances always have a type and a value (which are given
49 * at construction time). The type and value of a #GVariant instance
50 * can never change other than by the #GVariant itself being
51 * destroyed. A #GVariant cannot contain a pointer.
52 *
53 * #GVariant is reference counted using g_variant_ref() and
54 * g_variant_unref(). #GVariant also has floating reference counts --
55 * see g_variant_ref_sink().
56 *
57 * #GVariant is completely threadsafe. A #GVariant instance can be
58 * concurrently accessed in any way from any number of threads without
59 * problems.
60 *
61 * #GVariant is heavily optimised for dealing with data in serialised
62 * form. It works particularly well with data located in memory-mapped
63 * files. It can perform nearly all deserialisation operations in a
64 * small constant time, usually touching only a single memory page.
65 * Serialised #GVariant data can also be sent over the network.
66 *
67 * #GVariant is largely compatible with D-Bus. Almost all types of
68 * #GVariant instances can be sent over D-Bus. See #GVariantType for
69 * exceptions. (However, #GVariant's serialisation format is not the same
70 * as the serialisation format of a D-Bus message body: use #GDBusMessage,
71 * in the gio library, for those.)
72 *
73 * For space-efficiency, the #GVariant serialisation format does not
74 * automatically include the variant's length, type or endianness,
75 * which must either be implied from context (such as knowledge that a
76 * particular file format always contains a little-endian
77 * %G_VARIANT_TYPE_VARIANT which occupies the whole length of the file)
78 * or supplied out-of-band (for instance, a length, type and/or endianness
79 * indicator could be placed at the beginning of a file, network message
80 * or network stream).
81 *
82 * A #GVariant's size is limited mainly by any lower level operating
83 * system constraints, such as the number of bits in #gsize. For
84 * example, it is reasonable to have a 2GB file mapped into memory
85 * with #GMappedFile, and call g_variant_new_from_data() on it.
86 *
87 * For convenience to C programmers, #GVariant features powerful
88 * varargs-based value construction and destruction. This feature is
89 * designed to be embedded in other libraries.
90 *
91 * There is a Python-inspired text language for describing #GVariant
92 * values. #GVariant includes a printer for this language and a parser
93 * with type inferencing.
94 *
95 * ## Memory Use
96 *
97 * #GVariant tries to be quite efficient with respect to memory use.
98 * This section gives a rough idea of how much memory is used by the
99 * current implementation. The information here is subject to change
100 * in the future.
101 *
102 * The memory allocated by #GVariant can be grouped into 4 broad
103 * purposes: memory for serialised data, memory for the type
104 * information cache, buffer management memory and memory for the
105 * #GVariant structure itself.
106 *
107 * ## Serialised Data Memory
108 *
109 * This is the memory that is used for storing GVariant data in
110 * serialised form. This is what would be sent over the network or
111 * what would end up on disk, not counting any indicator of the
112 * endianness, or of the length or type of the top-level variant.
113 *
114 * The amount of memory required to store a boolean is 1 byte. 16,
115 * 32 and 64 bit integers and double precision floating point numbers
116 * use their "natural" size. Strings (including object path and
117 * signature strings) are stored with a nul terminator, and as such
118 * use the length of the string plus 1 byte.
119 *
120 * Maybe types use no space at all to represent the null value and
121 * use the same amount of space (sometimes plus one byte) as the
122 * equivalent non-maybe-typed value to represent the non-null case.
123 *
124 * Arrays use the amount of space required to store each of their
125 * members, concatenated. Additionally, if the items stored in an
126 * array are not of a fixed-size (ie: strings, other arrays, etc)
127 * then an additional framing offset is stored for each item. The
128 * size of this offset is either 1, 2 or 4 bytes depending on the
129 * overall size of the container. Additionally, extra padding bytes
130 * are added as required for alignment of child values.
131 *
132 * Tuples (including dictionary entries) use the amount of space
133 * required to store each of their members, concatenated, plus one
134 * framing offset (as per arrays) for each non-fixed-sized item in
135 * the tuple, except for the last one. Additionally, extra padding
136 * bytes are added as required for alignment of child values.
137 *
138 * Variants use the same amount of space as the item inside of the
139 * variant, plus 1 byte, plus the length of the type string for the
140 * item inside the variant.
141 *
142 * As an example, consider a dictionary mapping strings to variants.
143 * In the case that the dictionary is empty, 0 bytes are required for
144 * the serialisation.
145 *
146 * If we add an item "width" that maps to the int32 value of 500 then
147 * we will use 4 byte to store the int32 (so 6 for the variant
148 * containing it) and 6 bytes for the string. The variant must be
149 * aligned to 8 after the 6 bytes of the string, so that's 2 extra
150 * bytes. 6 (string) + 2 (padding) + 6 (variant) is 14 bytes used
151 * for the dictionary entry. An additional 1 byte is added to the
152 * array as a framing offset making a total of 15 bytes.
153 *
154 * If we add another entry, "title" that maps to a nullable string
155 * that happens to have a value of null, then we use 0 bytes for the
156 * null value (and 3 bytes for the variant to contain it along with
157 * its type string) plus 6 bytes for the string. Again, we need 2
158 * padding bytes. That makes a total of 6 + 2 + 3 = 11 bytes.
159 *
160 * We now require extra padding between the two items in the array.
161 * After the 14 bytes of the first item, that's 2 bytes required.
162 * We now require 2 framing offsets for an extra two
163 * bytes. 14 + 2 + 11 + 2 = 29 bytes to encode the entire two-item
164 * dictionary.
165 *
166 * ## Type Information Cache
167 *
168 * For each GVariant type that currently exists in the program a type
169 * information structure is kept in the type information cache. The
170 * type information structure is required for rapid deserialisation.
171 *
172 * Continuing with the above example, if a #GVariant exists with the
173 * type "a{sv}" then a type information struct will exist for
174 * "a{sv}", "{sv}", "s", and "v". Multiple uses of the same type
175 * will share the same type information. Additionally, all
176 * single-digit types are stored in read-only static memory and do
177 * not contribute to the writable memory footprint of a program using
178 * #GVariant.
179 *
180 * Aside from the type information structures stored in read-only
181 * memory, there are two forms of type information. One is used for
182 * container types where there is a single element type: arrays and
183 * maybe types. The other is used for container types where there
184 * are multiple element types: tuples and dictionary entries.
185 *
186 * Array type info structures are 6 * sizeof (void *), plus the
187 * memory required to store the type string itself. This means that
188 * on 32-bit systems, the cache entry for "a{sv}" would require 30
189 * bytes of memory (plus malloc overhead).
190 *
191 * Tuple type info structures are 6 * sizeof (void *), plus 4 *
192 * sizeof (void *) for each item in the tuple, plus the memory
193 * required to store the type string itself. A 2-item tuple, for
194 * example, would have a type information structure that consumed
195 * writable memory in the size of 14 * sizeof (void *) (plus type
196 * string) This means that on 32-bit systems, the cache entry for
197 * "{sv}" would require 61 bytes of memory (plus malloc overhead).
198 *
199 * This means that in total, for our "a{sv}" example, 91 bytes of
200 * type information would be allocated.
201 *
202 * The type information cache, additionally, uses a #GHashTable to
203 * store and lookup the cached items and stores a pointer to this
204 * hash table in static storage. The hash table is freed when there
205 * are zero items in the type cache.
206 *
207 * Although these sizes may seem large it is important to remember
208 * that a program will probably only have a very small number of
209 * different types of values in it and that only one type information
210 * structure is required for many different values of the same type.
211 *
212 * ## Buffer Management Memory
213 *
214 * #GVariant uses an internal buffer management structure to deal
215 * with the various different possible sources of serialised data
216 * that it uses. The buffer is responsible for ensuring that the
217 * correct call is made when the data is no longer in use by
218 * #GVariant. This may involve a g_free() or a g_slice_free() or
219 * even g_mapped_file_unref().
220 *
221 * One buffer management structure is used for each chunk of
222 * serialised data. The size of the buffer management structure
223 * is 4 * (void *). On 32-bit systems, that's 16 bytes.
224 *
225 * ## GVariant structure
226 *
227 * The size of a #GVariant structure is 6 * (void *). On 32-bit
228 * systems, that's 24 bytes.
229 *
230 * #GVariant structures only exist if they are explicitly created
231 * with API calls. For example, if a #GVariant is constructed out of
232 * serialised data for the example given above (with the dictionary)
233 * then although there are 9 individual values that comprise the
234 * entire dictionary (two keys, two values, two variants containing
235 * the values, two dictionary entries, plus the dictionary itself),
236 * only 1 #GVariant instance exists -- the one referring to the
237 * dictionary.
238 *
239 * If calls are made to start accessing the other values then
240 * #GVariant instances will exist for those values only for as long
241 * as they are in use (ie: until you call g_variant_unref()). The
242 * type information is shared. The serialised data and the buffer
243 * management structure for that serialised data is shared by the
244 * child.
245 *
246 * ## Summary
247 *
248 * To put the entire example together, for our dictionary mapping
249 * strings to variants (with two entries, as given above), we are
250 * using 91 bytes of memory for type information, 29 byes of memory
251 * for the serialised data, 16 bytes for buffer management and 24
252 * bytes for the #GVariant instance, or a total of 160 bytes, plus
253 * malloc overhead. If we were to use g_variant_get_child_value() to
254 * access the two dictionary entries, we would use an additional 48
255 * bytes. If we were to have other dictionaries of the same type, we
256 * would use more memory for the serialised data and buffer
257 * management for those dictionaries, but the type information would
258 * be shared.
259 */
260
261 /* definition of GVariant structure is in gvariant-core.c */
262
263 /* this is a g_return_val_if_fail() for making
264 * sure a (GVariant *) has the required type.
265 */
266 #define TYPE_CHECK(value, TYPE, val) \
267 if G_UNLIKELY (!g_variant_is_of_type (value, TYPE)) { \
268 g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, \
269 "g_variant_is_of_type (" #value \
270 ", " #TYPE ")"); \
271 return val; \
272 }
273
274 /* Numeric Type Constructor/Getters {{{1 */
275 /* < private >
276 * g_variant_new_from_trusted:
277 * @type: the #GVariantType
278 * @data: the data to use
279 * @size: the size of @data
280 *
281 * Constructs a new trusted #GVariant instance from the provided data.
282 * This is used to implement g_variant_new_* for all the basic types.
283 *
284 * Returns: a new floating #GVariant
285 */
286 static GVariant *
287 g_variant_new_from_trusted (const GVariantType *type,
288 gconstpointer data,
289 gsize size)
290 {
291 GVariant *value;
292 GBytes *bytes;
293
294 bytes = g_bytes_new (data, size);
295 value = g_variant_new_from_bytes (type, bytes, TRUE);
296 g_bytes_unref (bytes);
297
298 return value;
299 }
300
301 /**
302 * g_variant_new_boolean:
303 * @value: a #gboolean value
304 *
305 * Creates a new boolean #GVariant instance -- either %TRUE or %FALSE.
306 *
307 * Returns: (transfer none): a floating reference to a new boolean #GVariant instance
308 *
309 * Since: 2.24
310 **/
311 GVariant *
312 g_variant_new_boolean (gboolean value)
313 {
314 guchar v = value;
315
316 return g_variant_new_from_trusted (G_VARIANT_TYPE_BOOLEAN, &v, 1);
317 }
318
319 /**
320 * g_variant_get_boolean:
321 * @value: a boolean #GVariant instance
322 *
323 * Returns the boolean value of @value.
324 *
325 * It is an error to call this function with a @value of any type
326 * other than %G_VARIANT_TYPE_BOOLEAN.
327 *
328 * Returns: %TRUE or %FALSE
329 *
330 * Since: 2.24
331 **/
332 gboolean
333 g_variant_get_boolean (GVariant *value)
334 {
335 const guchar *data;
336
337 TYPE_CHECK (value, G_VARIANT_TYPE_BOOLEAN, FALSE);
338
339 data = g_variant_get_data (value);
340
341 return data != NULL ? *data != 0 : FALSE;
342 }
343
344 /* the constructors and accessors for byte, int{16,32,64}, handles and
345 * doubles all look pretty much exactly the same, so we reduce
346 * copy/pasting here.
347 */
348 #define NUMERIC_TYPE(TYPE, type, ctype) \
349 GVariant *g_variant_new_##type (ctype value) { \
350 return g_variant_new_from_trusted (G_VARIANT_TYPE_##TYPE, \
351 &value, sizeof value); \
352 } \
353 ctype g_variant_get_##type (GVariant *value) { \
354 const ctype *data; \
355 TYPE_CHECK (value, G_VARIANT_TYPE_ ## TYPE, 0); \
356 data = g_variant_get_data (value); \
357 return data != NULL ? *data : 0; \
358 }
359
360
361 /**
362 * g_variant_new_byte:
363 * @value: a #guint8 value
364 *
365 * Creates a new byte #GVariant instance.
366 *
367 * Returns: (transfer none): a floating reference to a new byte #GVariant instance
368 *
369 * Since: 2.24
370 **/
371 /**
372 * g_variant_get_byte:
373 * @value: a byte #GVariant instance
374 *
375 * Returns the byte value of @value.
376 *
377 * It is an error to call this function with a @value of any type
378 * other than %G_VARIANT_TYPE_BYTE.
379 *
380 * Returns: a #guchar
381 *
382 * Since: 2.24
383 **/
384 NUMERIC_TYPE (BYTE, byte, guchar)
385
386 /**
387 * g_variant_new_int16:
388 * @value: a #gint16 value
389 *
390 * Creates a new int16 #GVariant instance.
391 *
392 * Returns: (transfer none): a floating reference to a new int16 #GVariant instance
393 *
394 * Since: 2.24
395 **/
396 /**
397 * g_variant_get_int16:
398 * @value: a int16 #GVariant instance
399 *
400 * Returns the 16-bit signed integer value of @value.
401 *
402 * It is an error to call this function with a @value of any type
403 * other than %G_VARIANT_TYPE_INT16.
404 *
405 * Returns: a #gint16
406 *
407 * Since: 2.24
408 **/
409 NUMERIC_TYPE (INT16, int16, gint16)
410
411 /**
412 * g_variant_new_uint16:
413 * @value: a #guint16 value
414 *
415 * Creates a new uint16 #GVariant instance.
416 *
417 * Returns: (transfer none): a floating reference to a new uint16 #GVariant instance
418 *
419 * Since: 2.24
420 **/
421 /**
422 * g_variant_get_uint16:
423 * @value: a uint16 #GVariant instance
424 *
425 * Returns the 16-bit unsigned integer value of @value.
426 *
427 * It is an error to call this function with a @value of any type
428 * other than %G_VARIANT_TYPE_UINT16.
429 *
430 * Returns: a #guint16
431 *
432 * Since: 2.24
433 **/
434 NUMERIC_TYPE (UINT16, uint16, guint16)
435
436 /**
437 * g_variant_new_int32:
438 * @value: a #gint32 value
439 *
440 * Creates a new int32 #GVariant instance.
441 *
442 * Returns: (transfer none): a floating reference to a new int32 #GVariant instance
443 *
444 * Since: 2.24
445 **/
446 /**
447 * g_variant_get_int32:
448 * @value: a int32 #GVariant instance
449 *
450 * Returns the 32-bit signed integer value of @value.
451 *
452 * It is an error to call this function with a @value of any type
453 * other than %G_VARIANT_TYPE_INT32.
454 *
455 * Returns: a #gint32
456 *
457 * Since: 2.24
458 **/
459 NUMERIC_TYPE (INT32, int32, gint32)
460
461 /**
462 * g_variant_new_uint32:
463 * @value: a #guint32 value
464 *
465 * Creates a new uint32 #GVariant instance.
466 *
467 * Returns: (transfer none): a floating reference to a new uint32 #GVariant instance
468 *
469 * Since: 2.24
470 **/
471 /**
472 * g_variant_get_uint32:
473 * @value: a uint32 #GVariant instance
474 *
475 * Returns the 32-bit unsigned integer value of @value.
476 *
477 * It is an error to call this function with a @value of any type
478 * other than %G_VARIANT_TYPE_UINT32.
479 *
480 * Returns: a #guint32
481 *
482 * Since: 2.24
483 **/
484 NUMERIC_TYPE (UINT32, uint32, guint32)
485
486 /**
487 * g_variant_new_int64:
488 * @value: a #gint64 value
489 *
490 * Creates a new int64 #GVariant instance.
491 *
492 * Returns: (transfer none): a floating reference to a new int64 #GVariant instance
493 *
494 * Since: 2.24
495 **/
496 /**
497 * g_variant_get_int64:
498 * @value: a int64 #GVariant instance
499 *
500 * Returns the 64-bit signed integer value of @value.
501 *
502 * It is an error to call this function with a @value of any type
503 * other than %G_VARIANT_TYPE_INT64.
504 *
505 * Returns: a #gint64
506 *
507 * Since: 2.24
508 **/
509 NUMERIC_TYPE (INT64, int64, gint64)
510
511 /**
512 * g_variant_new_uint64:
513 * @value: a #guint64 value
514 *
515 * Creates a new uint64 #GVariant instance.
516 *
517 * Returns: (transfer none): a floating reference to a new uint64 #GVariant instance
518 *
519 * Since: 2.24
520 **/
521 /**
522 * g_variant_get_uint64:
523 * @value: a uint64 #GVariant instance
524 *
525 * Returns the 64-bit unsigned integer value of @value.
526 *
527 * It is an error to call this function with a @value of any type
528 * other than %G_VARIANT_TYPE_UINT64.
529 *
530 * Returns: a #guint64
531 *
532 * Since: 2.24
533 **/
534 NUMERIC_TYPE (UINT64, uint64, guint64)
535
536 /**
537 * g_variant_new_handle:
538 * @value: a #gint32 value
539 *
540 * Creates a new handle #GVariant instance.
541 *
542 * By convention, handles are indexes into an array of file descriptors
543 * that are sent alongside a D-Bus message. If you're not interacting
544 * with D-Bus, you probably don't need them.
545 *
546 * Returns: (transfer none): a floating reference to a new handle #GVariant instance
547 *
548 * Since: 2.24
549 **/
550 /**
551 * g_variant_get_handle:
552 * @value: a handle #GVariant instance
553 *
554 * Returns the 32-bit signed integer value of @value.
555 *
556 * It is an error to call this function with a @value of any type other
557 * than %G_VARIANT_TYPE_HANDLE.
558 *
559 * By convention, handles are indexes into an array of file descriptors
560 * that are sent alongside a D-Bus message. If you're not interacting
561 * with D-Bus, you probably don't need them.
562 *
563 * Returns: a #gint32
564 *
565 * Since: 2.24
566 **/
567 NUMERIC_TYPE (HANDLE, handle, gint32)
568
569 /**
570 * g_variant_new_double:
571 * @value: a #gdouble floating point value
572 *
573 * Creates a new double #GVariant instance.
574 *
575 * Returns: (transfer none): a floating reference to a new double #GVariant instance
576 *
577 * Since: 2.24
578 **/
579 /**
580 * g_variant_get_double:
581 * @value: a double #GVariant instance
582 *
583 * Returns the double precision floating point value of @value.
584 *
585 * It is an error to call this function with a @value of any type
586 * other than %G_VARIANT_TYPE_DOUBLE.
587 *
588 * Returns: a #gdouble
589 *
590 * Since: 2.24
591 **/
592 NUMERIC_TYPE (DOUBLE, double, gdouble)
593
594 /* Container type Constructor / Deconstructors {{{1 */
595 /**
596 * g_variant_new_maybe:
597 * @child_type: (allow-none): the #GVariantType of the child, or %NULL
598 * @child: (allow-none): the child value, or %NULL
599 *
600 * Depending on if @child is %NULL, either wraps @child inside of a
601 * maybe container or creates a Nothing instance for the given @type.
602 *
603 * At least one of @child_type and @child must be non-%NULL.
604 * If @child_type is non-%NULL then it must be a definite type.
605 * If they are both non-%NULL then @child_type must be the type
606 * of @child.
607 *
608 * If @child is a floating reference (see g_variant_ref_sink()), the new
609 * instance takes ownership of @child.
610 *
611 * Returns: (transfer none): a floating reference to a new #GVariant maybe instance
612 *
613 * Since: 2.24
614 **/
615 GVariant *
616 g_variant_new_maybe (const GVariantType *child_type,
617 GVariant *child)
618 {
619 GVariantType *maybe_type;
620 GVariant *value;
621
622 g_return_val_if_fail (child_type == NULL || g_variant_type_is_definite
623 (child_type), 0);
624 g_return_val_if_fail (child_type != NULL || child != NULL, NULL);
625 g_return_val_if_fail (child_type == NULL || child == NULL ||
626 g_variant_is_of_type (child, child_type),
627 NULL);
628
629 if (child_type == NULL)
630 child_type = g_variant_get_type (child);
631
632 maybe_type = g_variant_type_new_maybe (child_type);
633
634 if (child != NULL)
635 {
636 GVariant **children;
637 gboolean trusted;
638
639 children = g_new (GVariant *, 1);
640 children[0] = g_variant_ref_sink (child);
641 trusted = g_variant_is_trusted (children[0]);
642
643 value = g_variant_new_from_children (maybe_type, children, 1, trusted);
644 }
645 else
646 value = g_variant_new_from_children (maybe_type, NULL, 0, TRUE);
647
648 g_variant_type_free (maybe_type);
649
650 return value;
651 }
652
653 /**
654 * g_variant_get_maybe:
655 * @value: a maybe-typed value
656 *
657 * Given a maybe-typed #GVariant instance, extract its value. If the
658 * value is Nothing, then this function returns %NULL.
659 *
660 * Returns: (allow-none) (transfer full): the contents of @value, or %NULL
661 *
662 * Since: 2.24
663 **/
664 GVariant *
665 g_variant_get_maybe (GVariant *value)
666 {
667 TYPE_CHECK (value, G_VARIANT_TYPE_MAYBE, NULL);
668
669 if (g_variant_n_children (value))
670 return g_variant_get_child_value (value, 0);
671
672 return NULL;
673 }
674
675 /**
676 * g_variant_new_variant: (constructor)
677 * @value: a #GVariant instance
678 *
679 * Boxes @value. The result is a #GVariant instance representing a
680 * variant containing the original value.
681 *
682 * If @child is a floating reference (see g_variant_ref_sink()), the new
683 * instance takes ownership of @child.
684 *
685 * Returns: (transfer none): a floating reference to a new variant #GVariant instance
686 *
687 * Since: 2.24
688 **/
689 GVariant *
690 g_variant_new_variant (GVariant *value)
691 {
692 g_return_val_if_fail (value != NULL, NULL);
693
694 g_variant_ref_sink (value);
695
696 return g_variant_new_from_children (G_VARIANT_TYPE_VARIANT,
697 g_memdup (&value, sizeof value),
698 1, g_variant_is_trusted (value));
699 }
700
701 /**
702 * g_variant_get_variant:
703 * @value: a variant #GVariant instance
704 *
705 * Unboxes @value. The result is the #GVariant instance that was
706 * contained in @value.
707 *
708 * Returns: (transfer full): the item contained in the variant
709 *
710 * Since: 2.24
711 **/
712 GVariant *
713 g_variant_get_variant (GVariant *value)
714 {
715 TYPE_CHECK (value, G_VARIANT_TYPE_VARIANT, NULL);
716
717 return g_variant_get_child_value (value, 0);
718 }
719
720 /**
721 * g_variant_new_array:
722 * @child_type: (allow-none): the element type of the new array
723 * @children: (allow-none) (array length=n_children): an array of
724 * #GVariant pointers, the children
725 * @n_children: the length of @children
726 *
727 * Creates a new #GVariant array from @children.
728 *
729 * @child_type must be non-%NULL if @n_children is zero. Otherwise, the
730 * child type is determined by inspecting the first element of the
731 * @children array. If @child_type is non-%NULL then it must be a
732 * definite type.
733 *
734 * The items of the array are taken from the @children array. No entry
735 * in the @children array may be %NULL.
736 *
737 * All items in the array must have the same type, which must be the
738 * same as @child_type, if given.
739 *
740 * If the @children are floating references (see g_variant_ref_sink()), the
741 * new instance takes ownership of them as if via g_variant_ref_sink().
742 *
743 * Returns: (transfer none): a floating reference to a new #GVariant array
744 *
745 * Since: 2.24
746 **/
747 GVariant *
748 g_variant_new_array (const GVariantType *child_type,
749 GVariant * const *children,
750 gsize n_children)
751 {
752 GVariantType *array_type;
753 GVariant **my_children;
754 gboolean trusted;
755 GVariant *value;
756 gsize i;
757
758 g_return_val_if_fail (n_children > 0 || child_type != NULL, NULL);
759 g_return_val_if_fail (n_children == 0 || children != NULL, NULL);
760 g_return_val_if_fail (child_type == NULL ||
761 g_variant_type_is_definite (child_type), NULL);
762
763 my_children = g_new (GVariant *, n_children);
764 trusted = TRUE;
765
766 if (child_type == NULL)
767 child_type = g_variant_get_type (children[0]);
768 array_type = g_variant_type_new_array (child_type);
769
770 for (i = 0; i < n_children; i++)
771 {
772 TYPE_CHECK (children[i], child_type, NULL);
773 my_children[i] = g_variant_ref_sink (children[i]);
774 trusted &= g_variant_is_trusted (children[i]);
775 }
776
777 value = g_variant_new_from_children (array_type, my_children,
778 n_children, trusted);
779 g_variant_type_free (array_type);
780
781 return value;
782 }
783
784 /*< private >
785 * g_variant_make_tuple_type:
786 * @children: (array length=n_children): an array of GVariant *
787 * @n_children: the length of @children
788 *
789 * Return the type of a tuple containing @children as its items.
790 **/
791 static GVariantType *
792 g_variant_make_tuple_type (GVariant * const *children,
793 gsize n_children)
794 {
795 const GVariantType **types;
796 GVariantType *type;
797 gsize i;
798
799 types = g_new (const GVariantType *, n_children);
800
801 for (i = 0; i < n_children; i++)
802 types[i] = g_variant_get_type (children[i]);
803
804 type = g_variant_type_new_tuple (types, n_children);
805 g_free (types);
806
807 return type;
808 }
809
810 /**
811 * g_variant_new_tuple:
812 * @children: (array length=n_children): the items to make the tuple out of
813 * @n_children: the length of @children
814 *
815 * Creates a new tuple #GVariant out of the items in @children. The
816 * type is determined from the types of @children. No entry in the
817 * @children array may be %NULL.
818 *
819 * If @n_children is 0 then the unit tuple is constructed.
820 *
821 * If the @children are floating references (see g_variant_ref_sink()), the
822 * new instance takes ownership of them as if via g_variant_ref_sink().
823 *
824 * Returns: (transfer none): a floating reference to a new #GVariant tuple
825 *
826 * Since: 2.24
827 **/
828 GVariant *
829 g_variant_new_tuple (GVariant * const *children,
830 gsize n_children)
831 {
832 GVariantType *tuple_type;
833 GVariant **my_children;
834 gboolean trusted;
835 GVariant *value;
836 gsize i;
837
838 g_return_val_if_fail (n_children == 0 || children != NULL, NULL);
839
840 my_children = g_new (GVariant *, n_children);
841 trusted = TRUE;
842
843 for (i = 0; i < n_children; i++)
844 {
845 my_children[i] = g_variant_ref_sink (children[i]);
846 trusted &= g_variant_is_trusted (children[i]);
847 }
848
849 tuple_type = g_variant_make_tuple_type (children, n_children);
850 value = g_variant_new_from_children (tuple_type, my_children,
851 n_children, trusted);
852 g_variant_type_free (tuple_type);
853
854 return value;
855 }
856
857 /*< private >
858 * g_variant_make_dict_entry_type:
859 * @key: a #GVariant, the key
860 * @val: a #GVariant, the value
861 *
862 * Return the type of a dictionary entry containing @key and @val as its
863 * children.
864 **/
865 static GVariantType *
866 g_variant_make_dict_entry_type (GVariant *key,
867 GVariant *val)
868 {
869 return g_variant_type_new_dict_entry (g_variant_get_type (key),
870 g_variant_get_type (val));
871 }
872
873 /**
874 * g_variant_new_dict_entry: (constructor)
875 * @key: a basic #GVariant, the key
876 * @value: a #GVariant, the value
877 *
878 * Creates a new dictionary entry #GVariant. @key and @value must be
879 * non-%NULL. @key must be a value of a basic type (ie: not a container).
880 *
881 * If the @key or @value are floating references (see g_variant_ref_sink()),
882 * the new instance takes ownership of them as if via g_variant_ref_sink().
883 *
884 * Returns: (transfer none): a floating reference to a new dictionary entry #GVariant
885 *
886 * Since: 2.24
887 **/
888 GVariant *
889 g_variant_new_dict_entry (GVariant *key,
890 GVariant *value)
891 {
892 GVariantType *dict_type;
893 GVariant **children;
894 gboolean trusted;
895
896 g_return_val_if_fail (key != NULL && value != NULL, NULL);
897 g_return_val_if_fail (!g_variant_is_container (key), NULL);
898
899 children = g_new (GVariant *, 2);
900 children[0] = g_variant_ref_sink (key);
901 children[1] = g_variant_ref_sink (value);
902 trusted = g_variant_is_trusted (key) && g_variant_is_trusted (value);
903
904 dict_type = g_variant_make_dict_entry_type (key, value);
905 value = g_variant_new_from_children (dict_type, children, 2, trusted);
906 g_variant_type_free (dict_type);
907
908 return value;
909 }
910
911 /**
912 * g_variant_lookup: (skip)
913 * @dictionary: a dictionary #GVariant
914 * @key: the key to lookup in the dictionary
915 * @format_string: a GVariant format string
916 * @...: the arguments to unpack the value into
917 *
918 * Looks up a value in a dictionary #GVariant.
919 *
920 * This function is a wrapper around g_variant_lookup_value() and
921 * g_variant_get(). In the case that %NULL would have been returned,
922 * this function returns %FALSE. Otherwise, it unpacks the returned
923 * value and returns %TRUE.
924 *
925 * @format_string determines the C types that are used for unpacking
926 * the values and also determines if the values are copied or borrowed,
927 * see the section on
928 * [GVariant format strings][gvariant-format-strings-pointers].
929 *
930 * This function is currently implemented with a linear scan. If you
931 * plan to do many lookups then #GVariantDict may be more efficient.
932 *
933 * Returns: %TRUE if a value was unpacked
934 *
935 * Since: 2.28
936 */
937 gboolean
938 g_variant_lookup (GVariant *dictionary,
939 const gchar *key,
940 const gchar *format_string,
941 ...)
942 {
943 GVariantType *type;
944 GVariant *value;
945
946 /* flatten */
947 g_variant_get_data (dictionary);
948
949 type = g_variant_format_string_scan_type (format_string, NULL, NULL);
950 value = g_variant_lookup_value (dictionary, key, type);
951 g_variant_type_free (type);
952
953 if (value)
954 {
955 va_list ap;
956
957 va_start (ap, format_string);
958 g_variant_get_va (value, format_string, NULL, &ap);
959 g_variant_unref (value);
960 va_end (ap);
961
962 return TRUE;
963 }
964
965 else
966 return FALSE;
967 }
968
969 /**
970 * g_variant_lookup_value:
971 * @dictionary: a dictionary #GVariant
972 * @key: the key to lookup in the dictionary
973 * @expected_type: (allow-none): a #GVariantType, or %NULL
974 *
975 * Looks up a value in a dictionary #GVariant.
976 *
977 * This function works with dictionaries of the type a{s*} (and equally
978 * well with type a{o*}, but we only further discuss the string case
979 * for sake of clarity).
980 *
981 * In the event that @dictionary has the type a{sv}, the @expected_type
982 * string specifies what type of value is expected to be inside of the
983 * variant. If the value inside the variant has a different type then
984 * %NULL is returned. In the event that @dictionary has a value type other
985 * than v then @expected_type must directly match the key type and it is
986 * used to unpack the value directly or an error occurs.
987 *
988 * In either case, if @key is not found in @dictionary, %NULL is returned.
989 *
990 * If the key is found and the value has the correct type, it is
991 * returned. If @expected_type was specified then any non-%NULL return
992 * value will have this type.
993 *
994 * This function is currently implemented with a linear scan. If you
995 * plan to do many lookups then #GVariantDict may be more efficient.
996 *
997 * Returns: (transfer full): the value of the dictionary key, or %NULL
998 *
999 * Since: 2.28
1000 */
1001 GVariant *
1002 g_variant_lookup_value (GVariant *dictionary,
1003 const gchar *key,
1004 const GVariantType *expected_type)
1005 {
1006 GVariantIter iter;
1007 GVariant *entry;
1008 GVariant *value;
1009
1010 g_return_val_if_fail (g_variant_is_of_type (dictionary,
1011 G_VARIANT_TYPE ("a{s*}")) ||
1012 g_variant_is_of_type (dictionary,
1013 G_VARIANT_TYPE ("a{o*}")),
1014 NULL);
1015
1016 g_variant_iter_init (&iter, dictionary);
1017
1018 while ((entry = g_variant_iter_next_value (&iter)))
1019 {
1020 GVariant *entry_key;
1021 gboolean matches;
1022
1023 entry_key = g_variant_get_child_value (entry, 0);
1024 matches = strcmp (g_variant_get_string (entry_key, NULL), key) == 0;
1025 g_variant_unref (entry_key);
1026
1027 if (matches)
1028 break;
1029
1030 g_variant_unref (entry);
1031 }
1032
1033 if (entry == NULL)
1034 return NULL;
1035
1036 value = g_variant_get_child_value (entry, 1);
1037 g_variant_unref (entry);
1038
1039 if (g_variant_is_of_type (value, G_VARIANT_TYPE_VARIANT))
1040 {
1041 GVariant *tmp;
1042
1043 tmp = g_variant_get_variant (value);
1044 g_variant_unref (value);
1045
1046 if (expected_type && !g_variant_is_of_type (tmp, expected_type))
1047 {
1048 g_variant_unref (tmp);
1049 tmp = NULL;
1050 }
1051
1052 value = tmp;
1053 }
1054
1055 g_return_val_if_fail (expected_type == NULL || value == NULL ||
1056 g_variant_is_of_type (value, expected_type), NULL);
1057
1058 return value;
1059 }
1060
1061 /**
1062 * g_variant_get_fixed_array:
1063 * @value: a #GVariant array with fixed-sized elements
1064 * @n_elements: (out): a pointer to the location to store the number of items
1065 * @element_size: the size of each element
1066 *
1067 * Provides access to the serialised data for an array of fixed-sized
1068 * items.
1069 *
1070 * @value must be an array with fixed-sized elements. Numeric types are
1071 * fixed-size, as are tuples containing only other fixed-sized types.
1072 *
1073 * @element_size must be the size of a single element in the array,
1074 * as given by the section on
1075 * [serialized data memory][gvariant-serialised-data-memory].
1076 *
1077 * In particular, arrays of these fixed-sized types can be interpreted
1078 * as an array of the given C type, with @element_size set to the size
1079 * the appropriate type:
1080 * - %G_VARIANT_TYPE_INT16 (etc.): #gint16 (etc.)
1081 * - %G_VARIANT_TYPE_BOOLEAN: #guchar (not #gboolean!)
1082 * - %G_VARIANT_TYPE_BYTE: #guchar
1083 * - %G_VARIANT_TYPE_HANDLE: #guint32
1084 * - %G_VARIANT_TYPE_DOUBLE: #gdouble
1085 *
1086 * For example, if calling this function for an array of 32-bit integers,
1087 * you might say sizeof(gint32). This value isn't used except for the purpose
1088 * of a double-check that the form of the serialised data matches the caller's
1089 * expectation.
1090 *
1091 * @n_elements, which must be non-%NULL is set equal to the number of
1092 * items in the array.
1093 *
1094 * Returns: (array length=n_elements) (transfer none): a pointer to
1095 * the fixed array
1096 *
1097 * Since: 2.24
1098 **/
1099 gconstpointer
1100 g_variant_get_fixed_array (GVariant *value,
1101 gsize *n_elements,
1102 gsize element_size)
1103 {
1104 GVariantTypeInfo *array_info;
1105 gsize array_element_size;
1106 gconstpointer data;
1107 gsize size;
1108
1109 TYPE_CHECK (value, G_VARIANT_TYPE_ARRAY, NULL);
1110
1111 g_return_val_if_fail (n_elements != NULL, NULL);
1112 g_return_val_if_fail (element_size > 0, NULL);
1113
1114 array_info = g_variant_get_type_info (value);
1115 g_variant_type_info_query_element (array_info, NULL, &array_element_size);
1116
1117 g_return_val_if_fail (array_element_size, NULL);
1118
1119 if G_UNLIKELY (array_element_size != element_size)
1120 {
1121 if (array_element_size)
1122 g_critical ("g_variant_get_fixed_array: assertion "
1123 "'g_variant_array_has_fixed_size (value, element_size)' "
1124 "failed: array size %"G_GSIZE_FORMAT" does not match "
1125 "given element_size %"G_GSIZE_FORMAT".",
1126 array_element_size, element_size);
1127 else
1128 g_critical ("g_variant_get_fixed_array: assertion "
1129 "'g_variant_array_has_fixed_size (value, element_size)' "
1130 "failed: array does not have fixed size.");
1131 }
1132
1133 data = g_variant_get_data (value);
1134 size = g_variant_get_size (value);
1135
1136 if (size % element_size)
1137 *n_elements = 0;
1138 else
1139 *n_elements = size / element_size;
1140
1141 if (*n_elements)
1142 return data;
1143
1144 return NULL;
1145 }
1146
1147 /**
1148 * g_variant_new_fixed_array:
1149 * @element_type: the #GVariantType of each element
1150 * @elements: a pointer to the fixed array of contiguous elements
1151 * @n_elements: the number of elements
1152 * @element_size: the size of each element
1153 *
1154 * Provides access to the serialised data for an array of fixed-sized
1155 * items.
1156 *
1157 * @value must be an array with fixed-sized elements. Numeric types are
1158 * fixed-size as are tuples containing only other fixed-sized types.
1159 *
1160 * @element_size must be the size of a single element in the array.
1161 * For example, if calling this function for an array of 32-bit integers,
1162 * you might say sizeof(gint32). This value isn't used except for the purpose
1163 * of a double-check that the form of the serialised data matches the caller's
1164 * expectation.
1165 *
1166 * @n_elements, which must be non-%NULL is set equal to the number of
1167 * items in the array.
1168 *
1169 * Returns: (transfer none): a floating reference to a new array #GVariant instance
1170 *
1171 * Since: 2.32
1172 **/
1173 GVariant *
1174 g_variant_new_fixed_array (const GVariantType *element_type,
1175 gconstpointer elements,
1176 gsize n_elements,
1177 gsize element_size)
1178 {
1179 GVariantType *array_type;
1180 gsize array_element_size;
1181 GVariantTypeInfo *array_info;
1182 GVariant *value;
1183 gpointer data;
1184
1185 g_return_val_if_fail (g_variant_type_is_definite (element_type), NULL);
1186 g_return_val_if_fail (element_size > 0, NULL);
1187
1188 array_type = g_variant_type_new_array (element_type);
1189 array_info = g_variant_type_info_get (array_type);
1190 g_variant_type_info_query_element (array_info, NULL, &array_element_size);
1191 if G_UNLIKELY (array_element_size != element_size)
1192 {
1193 if (array_element_size)
1194 g_critical ("g_variant_new_fixed_array: array size %" G_GSIZE_FORMAT
1195 " does not match given element_size %" G_GSIZE_FORMAT ".",
1196 array_element_size, element_size);
1197 else
1198 g_critical ("g_variant_get_fixed_array: array does not have fixed size.");
1199 return NULL;
1200 }
1201
1202 data = g_memdup (elements, n_elements * element_size);
1203 value = g_variant_new_from_data (array_type, data,
1204 n_elements * element_size,
1205 FALSE, g_free, data);
1206
1207 g_variant_type_free (array_type);
1208 g_variant_type_info_unref (array_info);
1209
1210 return value;
1211 }
1212
1213 /* String type constructor/getters/validation {{{1 */
1214 /**
1215 * g_variant_new_string:
1216 * @string: a normal utf8 nul-terminated string
1217 *
1218 * Creates a string #GVariant with the contents of @string.
1219 *
1220 * @string must be valid utf8.
1221 *
1222 * Returns: (transfer none): a floating reference to a new string #GVariant instance
1223 *
1224 * Since: 2.24
1225 **/
1226 GVariant *
1227 g_variant_new_string (const gchar *string)
1228 {
1229 g_return_val_if_fail (string != NULL, NULL);
1230 g_return_val_if_fail (g_utf8_validate (string, -1, NULL), NULL);
1231
1232 return g_variant_new_from_trusted (G_VARIANT_TYPE_STRING,
1233 string, strlen (string) + 1);
1234 }
1235
1236 /**
1237 * g_variant_new_take_string: (skip)
1238 * @string: a normal utf8 nul-terminated string
1239 *
1240 * Creates a string #GVariant with the contents of @string.
1241 *
1242 * @string must be valid utf8.
1243 *
1244 * This function consumes @string. g_free() will be called on @string
1245 * when it is no longer required.
1246 *
1247 * You must not modify or access @string in any other way after passing
1248 * it to this function. It is even possible that @string is immediately
1249 * freed.
1250 *
1251 * Returns: (transfer none): a floating reference to a new string
1252 * #GVariant instance
1253 *
1254 * Since: 2.38
1255 **/
1256 GVariant *
1257 g_variant_new_take_string (gchar *string)
1258 {
1259 GVariant *value;
1260 GBytes *bytes;
1261
1262 g_return_val_if_fail (string != NULL, NULL);
1263 g_return_val_if_fail (g_utf8_validate (string, -1, NULL), NULL);
1264
1265 bytes = g_bytes_new_take (string, strlen (string) + 1);
1266 value = g_variant_new_from_bytes (G_VARIANT_TYPE_STRING, bytes, TRUE);
1267 g_bytes_unref (bytes);
1268
1269 return value;
1270 }
1271
1272 /**
1273 * g_variant_new_printf: (skip)
1274 * @format_string: a printf-style format string
1275 * @...: arguments for @format_string
1276 *
1277 * Creates a string-type GVariant using printf formatting.
1278 *
1279 * This is similar to calling g_strdup_printf() and then
1280 * g_variant_new_string() but it saves a temporary variable and an
1281 * unnecessary copy.
1282 *
1283 * Returns: (transfer none): a floating reference to a new string
1284 * #GVariant instance
1285 *
1286 * Since: 2.38
1287 **/
1288 GVariant *
1289 g_variant_new_printf (const gchar *format_string,
1290 ...)
1291 {
1292 GVariant *value;
1293 GBytes *bytes;
1294 gchar *string;
1295 va_list ap;
1296
1297 g_return_val_if_fail (format_string != NULL, NULL);
1298
1299 va_start (ap, format_string);
1300 string = g_strdup_vprintf (format_string, ap);
1301 va_end (ap);
1302
1303 bytes = g_bytes_new_take (string, strlen (string) + 1);
1304 value = g_variant_new_from_bytes (G_VARIANT_TYPE_STRING, bytes, TRUE);
1305 g_bytes_unref (bytes);
1306
1307 return value;
1308 }
1309
1310 /**
1311 * g_variant_new_object_path:
1312 * @object_path: a normal C nul-terminated string
1313 *
1314 * Creates a D-Bus object path #GVariant with the contents of @string.
1315 * @string must be a valid D-Bus object path. Use
1316 * g_variant_is_object_path() if you're not sure.
1317 *
1318 * Returns: (transfer none): a floating reference to a new object path #GVariant instance
1319 *
1320 * Since: 2.24
1321 **/
1322 GVariant *
1323 g_variant_new_object_path (const gchar *object_path)
1324 {
1325 g_return_val_if_fail (g_variant_is_object_path (object_path), NULL);
1326
1327 return g_variant_new_from_trusted (G_VARIANT_TYPE_OBJECT_PATH,
1328 object_path, strlen (object_path) + 1);
1329 }
1330
1331 /**
1332 * g_variant_is_object_path:
1333 * @string: a normal C nul-terminated string
1334 *
1335 * Determines if a given string is a valid D-Bus object path. You
1336 * should ensure that a string is a valid D-Bus object path before
1337 * passing it to g_variant_new_object_path().
1338 *
1339 * A valid object path starts with '/' followed by zero or more
1340 * sequences of characters separated by '/' characters. Each sequence
1341 * must contain only the characters "[A-Z][a-z][0-9]_". No sequence
1342 * (including the one following the final '/' character) may be empty.
1343 *
1344 * Returns: %TRUE if @string is a D-Bus object path
1345 *
1346 * Since: 2.24
1347 **/
1348 gboolean
1349 g_variant_is_object_path (const gchar *string)
1350 {
1351 g_return_val_if_fail (string != NULL, FALSE);
1352
1353 return g_variant_serialiser_is_object_path (string, strlen (string) + 1);
1354 }
1355
1356 /**
1357 * g_variant_new_signature:
1358 * @signature: a normal C nul-terminated string
1359 *
1360 * Creates a D-Bus type signature #GVariant with the contents of
1361 * @string. @string must be a valid D-Bus type signature. Use
1362 * g_variant_is_signature() if you're not sure.
1363 *
1364 * Returns: (transfer none): a floating reference to a new signature #GVariant instance
1365 *
1366 * Since: 2.24
1367 **/
1368 GVariant *
1369 g_variant_new_signature (const gchar *signature)
1370 {
1371 g_return_val_if_fail (g_variant_is_signature (signature), NULL);
1372
1373 return g_variant_new_from_trusted (G_VARIANT_TYPE_SIGNATURE,
1374 signature, strlen (signature) + 1);
1375 }
1376
1377 /**
1378 * g_variant_is_signature:
1379 * @string: a normal C nul-terminated string
1380 *
1381 * Determines if a given string is a valid D-Bus type signature. You
1382 * should ensure that a string is a valid D-Bus type signature before
1383 * passing it to g_variant_new_signature().
1384 *
1385 * D-Bus type signatures consist of zero or more definite #GVariantType
1386 * strings in sequence.
1387 *
1388 * Returns: %TRUE if @string is a D-Bus type signature
1389 *
1390 * Since: 2.24
1391 **/
1392 gboolean
1393 g_variant_is_signature (const gchar *string)
1394 {
1395 g_return_val_if_fail (string != NULL, FALSE);
1396
1397 return g_variant_serialiser_is_signature (string, strlen (string) + 1);
1398 }
1399
1400 /**
1401 * g_variant_get_string:
1402 * @value: a string #GVariant instance
1403 * @length: (allow-none) (default 0) (out): a pointer to a #gsize,
1404 * to store the length
1405 *
1406 * Returns the string value of a #GVariant instance with a string
1407 * type. This includes the types %G_VARIANT_TYPE_STRING,
1408 * %G_VARIANT_TYPE_OBJECT_PATH and %G_VARIANT_TYPE_SIGNATURE.
1409 *
1410 * The string will always be utf8 encoded.
1411 *
1412 * If @length is non-%NULL then the length of the string (in bytes) is
1413 * returned there. For trusted values, this information is already
1414 * known. For untrusted values, a strlen() will be performed.
1415 *
1416 * It is an error to call this function with a @value of any type
1417 * other than those three.
1418 *
1419 * The return value remains valid as long as @value exists.
1420 *
1421 * Returns: (transfer none): the constant string, utf8 encoded
1422 *
1423 * Since: 2.24
1424 **/
1425 const gchar *
1426 g_variant_get_string (GVariant *value,
1427 gsize *length)
1428 {
1429 gconstpointer data;
1430 gsize size;
1431
1432 g_return_val_if_fail (value != NULL, NULL);
1433 g_return_val_if_fail (
1434 g_variant_is_of_type (value, G_VARIANT_TYPE_STRING) ||
1435 g_variant_is_of_type (value, G_VARIANT_TYPE_OBJECT_PATH) ||
1436 g_variant_is_of_type (value, G_VARIANT_TYPE_SIGNATURE), NULL);
1437
1438 data = g_variant_get_data (value);
1439 size = g_variant_get_size (value);
1440
1441 if (!g_variant_is_trusted (value))
1442 {
1443 switch (g_variant_classify (value))
1444 {
1445 case G_VARIANT_CLASS_STRING:
1446 if (g_variant_serialiser_is_string (data, size))
1447 break;
1448
1449 data = "";
1450 size = 1;
1451 break;
1452
1453 case G_VARIANT_CLASS_OBJECT_PATH:
1454 if (g_variant_serialiser_is_object_path (data, size))
1455 break;
1456
1457 data = "/";
1458 size = 2;
1459 break;
1460
1461 case G_VARIANT_CLASS_SIGNATURE:
1462 if (g_variant_serialiser_is_signature (data, size))
1463 break;
1464
1465 data = "";
1466 size = 1;
1467 break;
1468
1469 default:
1470 g_assert_not_reached ();
1471 }
1472 }
1473
1474 if (length)
1475 *length = size - 1;
1476
1477 return data;
1478 }
1479
1480 /**
1481 * g_variant_dup_string:
1482 * @value: a string #GVariant instance
1483 * @length: (out): a pointer to a #gsize, to store the length
1484 *
1485 * Similar to g_variant_get_string() except that instead of returning
1486 * a constant string, the string is duplicated.
1487 *
1488 * The string will always be utf8 encoded.
1489 *
1490 * The return value must be freed using g_free().
1491 *
1492 * Returns: (transfer full): a newly allocated string, utf8 encoded
1493 *
1494 * Since: 2.24
1495 **/
1496 gchar *
1497 g_variant_dup_string (GVariant *value,
1498 gsize *length)
1499 {
1500 return g_strdup (g_variant_get_string (value, length));
1501 }
1502
1503 /**
1504 * g_variant_new_strv:
1505 * @strv: (array length=length) (element-type utf8): an array of strings
1506 * @length: the length of @strv, or -1
1507 *
1508 * Constructs an array of strings #GVariant from the given array of
1509 * strings.
1510 *
1511 * If @length is -1 then @strv is %NULL-terminated.
1512 *
1513 * Returns: (transfer none): a new floating #GVariant instance
1514 *
1515 * Since: 2.24
1516 **/
1517 GVariant *
1518 g_variant_new_strv (const gchar * const *strv,
1519 gssize length)
1520 {
1521 GVariant **strings;
1522 gsize i;
1523
1524 g_return_val_if_fail (length == 0 || strv != NULL, NULL);
1525
1526 if (length < 0)
1527 length = g_strv_length ((gchar **) strv);
1528
1529 strings = g_new (GVariant *, length);
1530 for (i = 0; i < length; i++)
1531 strings[i] = g_variant_ref_sink (g_variant_new_string (strv[i]));
1532
1533 return g_variant_new_from_children (G_VARIANT_TYPE_STRING_ARRAY,
1534 strings, length, TRUE);
1535 }
1536
1537 /**
1538 * g_variant_get_strv:
1539 * @value: an array of strings #GVariant
1540 * @length: (out) (allow-none): the length of the result, or %NULL
1541 *
1542 * Gets the contents of an array of strings #GVariant. This call
1543 * makes a shallow copy; the return result should be released with
1544 * g_free(), but the individual strings must not be modified.
1545 *
1546 * If @length is non-%NULL then the number of elements in the result
1547 * is stored there. In any case, the resulting array will be
1548 * %NULL-terminated.
1549 *
1550 * For an empty array, @length will be set to 0 and a pointer to a
1551 * %NULL pointer will be returned.
1552 *
1553 * Returns: (array length=length zero-terminated=1) (transfer container): an array of constant strings
1554 *
1555 * Since: 2.24
1556 **/
1557 const gchar **
1558 g_variant_get_strv (GVariant *value,
1559 gsize *length)
1560 {
1561 const gchar **strv;
1562 gsize n;
1563 gsize i;
1564
1565 TYPE_CHECK (value, G_VARIANT_TYPE_STRING_ARRAY, NULL);
1566
1567 g_variant_get_data (value);
1568 n = g_variant_n_children (value);
1569 strv = g_new (const gchar *, n + 1);
1570
1571 for (i = 0; i < n; i++)
1572 {
1573 GVariant *string;
1574
1575 string = g_variant_get_child_value (value, i);
1576 strv[i] = g_variant_get_string (string, NULL);
1577 g_variant_unref (string);
1578 }
1579 strv[i] = NULL;
1580
1581 if (length)
1582 *length = n;
1583
1584 return strv;
1585 }
1586
1587 /**
1588 * g_variant_dup_strv:
1589 * @value: an array of strings #GVariant
1590 * @length: (out) (allow-none): the length of the result, or %NULL
1591 *
1592 * Gets the contents of an array of strings #GVariant. This call
1593 * makes a deep copy; the return result should be released with
1594 * g_strfreev().
1595 *
1596 * If @length is non-%NULL then the number of elements in the result
1597 * is stored there. In any case, the resulting array will be
1598 * %NULL-terminated.
1599 *
1600 * For an empty array, @length will be set to 0 and a pointer to a
1601 * %NULL pointer will be returned.
1602 *
1603 * Returns: (array length=length zero-terminated=1) (transfer full): an array of strings
1604 *
1605 * Since: 2.24
1606 **/
1607 gchar **
1608 g_variant_dup_strv (GVariant *value,
1609 gsize *length)
1610 {
1611 gchar **strv;
1612 gsize n;
1613 gsize i;
1614
1615 TYPE_CHECK (value, G_VARIANT_TYPE_STRING_ARRAY, NULL);
1616
1617 n = g_variant_n_children (value);
1618 strv = g_new (gchar *, n + 1);
1619
1620 for (i = 0; i < n; i++)
1621 {
1622 GVariant *string;
1623
1624 string = g_variant_get_child_value (value, i);
1625 strv[i] = g_variant_dup_string (string, NULL);
1626 g_variant_unref (string);
1627 }
1628 strv[i] = NULL;
1629
1630 if (length)
1631 *length = n;
1632
1633 return strv;
1634 }
1635
1636 /**
1637 * g_variant_new_objv:
1638 * @strv: (array length=length) (element-type utf8): an array of strings
1639 * @length: the length of @strv, or -1
1640 *
1641 * Constructs an array of object paths #GVariant from the given array of
1642 * strings.
1643 *
1644 * Each string must be a valid #GVariant object path; see
1645 * g_variant_is_object_path().
1646 *
1647 * If @length is -1 then @strv is %NULL-terminated.
1648 *
1649 * Returns: (transfer none): a new floating #GVariant instance
1650 *
1651 * Since: 2.30
1652 **/
1653 GVariant *
1654 g_variant_new_objv (const gchar * const *strv,
1655 gssize length)
1656 {
1657 GVariant **strings;
1658 gsize i;
1659
1660 g_return_val_if_fail (length == 0 || strv != NULL, NULL);
1661
1662 if (length < 0)
1663 length = g_strv_length ((gchar **) strv);
1664
1665 strings = g_new (GVariant *, length);
1666 for (i = 0; i < length; i++)
1667 strings[i] = g_variant_ref_sink (g_variant_new_object_path (strv[i]));
1668
1669 return g_variant_new_from_children (G_VARIANT_TYPE_OBJECT_PATH_ARRAY,
1670 strings, length, TRUE);
1671 }
1672
1673 /**
1674 * g_variant_get_objv:
1675 * @value: an array of object paths #GVariant
1676 * @length: (out) (allow-none): the length of the result, or %NULL
1677 *
1678 * Gets the contents of an array of object paths #GVariant. This call
1679 * makes a shallow copy; the return result should be released with
1680 * g_free(), but the individual strings must not be modified.
1681 *
1682 * If @length is non-%NULL then the number of elements in the result
1683 * is stored there. In any case, the resulting array will be
1684 * %NULL-terminated.
1685 *
1686 * For an empty array, @length will be set to 0 and a pointer to a
1687 * %NULL pointer will be returned.
1688 *
1689 * Returns: (array length=length zero-terminated=1) (transfer container): an array of constant strings
1690 *
1691 * Since: 2.30
1692 **/
1693 const gchar **
1694 g_variant_get_objv (GVariant *value,
1695 gsize *length)
1696 {
1697 const gchar **strv;
1698 gsize n;
1699 gsize i;
1700
1701 TYPE_CHECK (value, G_VARIANT_TYPE_OBJECT_PATH_ARRAY, NULL);
1702
1703 g_variant_get_data (value);
1704 n = g_variant_n_children (value);
1705 strv = g_new (const gchar *, n + 1);
1706
1707 for (i = 0; i < n; i++)
1708 {
1709 GVariant *string;
1710
1711 string = g_variant_get_child_value (value, i);
1712 strv[i] = g_variant_get_string (string, NULL);
1713 g_variant_unref (string);
1714 }
1715 strv[i] = NULL;
1716
1717 if (length)
1718 *length = n;
1719
1720 return strv;
1721 }
1722
1723 /**
1724 * g_variant_dup_objv:
1725 * @value: an array of object paths #GVariant
1726 * @length: (out) (allow-none): the length of the result, or %NULL
1727 *
1728 * Gets the contents of an array of object paths #GVariant. This call
1729 * makes a deep copy; the return result should be released with
1730 * g_strfreev().
1731 *
1732 * If @length is non-%NULL then the number of elements in the result
1733 * is stored there. In any case, the resulting array will be
1734 * %NULL-terminated.
1735 *
1736 * For an empty array, @length will be set to 0 and a pointer to a
1737 * %NULL pointer will be returned.
1738 *
1739 * Returns: (array length=length zero-terminated=1) (transfer full): an array of strings
1740 *
1741 * Since: 2.30
1742 **/
1743 gchar **
1744 g_variant_dup_objv (GVariant *value,
1745 gsize *length)
1746 {
1747 gchar **strv;
1748 gsize n;
1749 gsize i;
1750
1751 TYPE_CHECK (value, G_VARIANT_TYPE_OBJECT_PATH_ARRAY, NULL);
1752
1753 n = g_variant_n_children (value);
1754 strv = g_new (gchar *, n + 1);
1755
1756 for (i = 0; i < n; i++)
1757 {
1758 GVariant *string;
1759
1760 string = g_variant_get_child_value (value, i);
1761 strv[i] = g_variant_dup_string (string, NULL);
1762 g_variant_unref (string);
1763 }
1764 strv[i] = NULL;
1765
1766 if (length)
1767 *length = n;
1768
1769 return strv;
1770 }
1771
1772
1773 /**
1774 * g_variant_new_bytestring:
1775 * @string: (array zero-terminated=1) (element-type guint8): a normal
1776 * nul-terminated string in no particular encoding
1777 *
1778 * Creates an array-of-bytes #GVariant with the contents of @string.
1779 * This function is just like g_variant_new_string() except that the
1780 * string need not be valid utf8.
1781 *
1782 * The nul terminator character at the end of the string is stored in
1783 * the array.
1784 *
1785 * Returns: (transfer none): a floating reference to a new bytestring #GVariant instance
1786 *
1787 * Since: 2.26
1788 **/
1789 GVariant *
1790 g_variant_new_bytestring (const gchar *string)
1791 {
1792 g_return_val_if_fail (string != NULL, NULL);
1793
1794 return g_variant_new_from_trusted (G_VARIANT_TYPE_BYTESTRING,
1795 string, strlen (string) + 1);
1796 }
1797
1798 /**
1799 * g_variant_get_bytestring:
1800 * @value: an array-of-bytes #GVariant instance
1801 *
1802 * Returns the string value of a #GVariant instance with an
1803 * array-of-bytes type. The string has no particular encoding.
1804 *
1805 * If the array does not end with a nul terminator character, the empty
1806 * string is returned. For this reason, you can always trust that a
1807 * non-%NULL nul-terminated string will be returned by this function.
1808 *
1809 * If the array contains a nul terminator character somewhere other than
1810 * the last byte then the returned string is the string, up to the first
1811 * such nul character.
1812 *
1813 * It is an error to call this function with a @value that is not an
1814 * array of bytes.
1815 *
1816 * The return value remains valid as long as @value exists.
1817 *
1818 * Returns: (transfer none) (array zero-terminated=1) (element-type guint8):
1819 * the constant string
1820 *
1821 * Since: 2.26
1822 **/
1823 const gchar *
1824 g_variant_get_bytestring (GVariant *value)
1825 {
1826 const gchar *string;
1827 gsize size;
1828
1829 TYPE_CHECK (value, G_VARIANT_TYPE_BYTESTRING, NULL);
1830
1831 /* Won't be NULL since this is an array type */
1832 string = g_variant_get_data (value);
1833 size = g_variant_get_size (value);
1834
1835 if (size && string[size - 1] == '\0')
1836 return string;
1837 else
1838 return "";
1839 }
1840
1841 /**
1842 * g_variant_dup_bytestring:
1843 * @value: an array-of-bytes #GVariant instance
1844 * @length: (out) (allow-none) (default NULL): a pointer to a #gsize, to store
1845 * the length (not including the nul terminator)
1846 *
1847 * Similar to g_variant_get_bytestring() except that instead of
1848 * returning a constant string, the string is duplicated.
1849 *
1850 * The return value must be freed using g_free().
1851 *
1852 * Returns: (transfer full) (array zero-terminated=1 length=length) (element-type guint8):
1853 * a newly allocated string
1854 *
1855 * Since: 2.26
1856 **/
1857 gchar *
1858 g_variant_dup_bytestring (GVariant *value,
1859 gsize *length)
1860 {
1861 const gchar *original = g_variant_get_bytestring (value);
1862 gsize size;
1863
1864 /* don't crash in case get_bytestring() had an assert failure */
1865 if (original == NULL)
1866 return NULL;
1867
1868 size = strlen (original);
1869
1870 if (length)
1871 *length = size;
1872
1873 return g_memdup (original, size + 1);
1874 }
1875
1876 /**
1877 * g_variant_new_bytestring_array:
1878 * @strv: (array length=length): an array of strings
1879 * @length: the length of @strv, or -1
1880 *
1881 * Constructs an array of bytestring #GVariant from the given array of
1882 * strings.
1883 *
1884 * If @length is -1 then @strv is %NULL-terminated.
1885 *
1886 * Returns: (transfer none): a new floating #GVariant instance
1887 *
1888 * Since: 2.26
1889 **/
1890 GVariant *
1891 g_variant_new_bytestring_array (const gchar * const *strv,
1892 gssize length)
1893 {
1894 GVariant **strings;
1895 gsize i;
1896
1897 g_return_val_if_fail (length == 0 || strv != NULL, NULL);
1898
1899 if (length < 0)
1900 length = g_strv_length ((gchar **) strv);
1901
1902 strings = g_new (GVariant *, length);
1903 for (i = 0; i < length; i++)
1904 strings[i] = g_variant_ref_sink (g_variant_new_bytestring (strv[i]));
1905
1906 return g_variant_new_from_children (G_VARIANT_TYPE_BYTESTRING_ARRAY,
1907 strings, length, TRUE);
1908 }
1909
1910 /**
1911 * g_variant_get_bytestring_array:
1912 * @value: an array of array of bytes #GVariant ('aay')
1913 * @length: (out) (allow-none): the length of the result, or %NULL
1914 *
1915 * Gets the contents of an array of array of bytes #GVariant. This call
1916 * makes a shallow copy; the return result should be released with
1917 * g_free(), but the individual strings must not be modified.
1918 *
1919 * If @length is non-%NULL then the number of elements in the result is
1920 * stored there. In any case, the resulting array will be
1921 * %NULL-terminated.
1922 *
1923 * For an empty array, @length will be set to 0 and a pointer to a
1924 * %NULL pointer will be returned.
1925 *
1926 * Returns: (array length=length) (transfer container): an array of constant strings
1927 *
1928 * Since: 2.26
1929 **/
1930 const gchar **
1931 g_variant_get_bytestring_array (GVariant *value,
1932 gsize *length)
1933 {
1934 const gchar **strv;
1935 gsize n;
1936 gsize i;
1937
1938 TYPE_CHECK (value, G_VARIANT_TYPE_BYTESTRING_ARRAY, NULL);
1939
1940 g_variant_get_data (value);
1941 n = g_variant_n_children (value);
1942 strv = g_new (const gchar *, n + 1);
1943
1944 for (i = 0; i < n; i++)
1945 {
1946 GVariant *string;
1947
1948 string = g_variant_get_child_value (value, i);
1949 strv[i] = g_variant_get_bytestring (string);
1950 g_variant_unref (string);
1951 }
1952 strv[i] = NULL;
1953
1954 if (length)
1955 *length = n;
1956
1957 return strv;
1958 }
1959
1960 /**
1961 * g_variant_dup_bytestring_array:
1962 * @value: an array of array of bytes #GVariant ('aay')
1963 * @length: (out) (allow-none): the length of the result, or %NULL
1964 *
1965 * Gets the contents of an array of array of bytes #GVariant. This call
1966 * makes a deep copy; the return result should be released with
1967 * g_strfreev().
1968 *
1969 * If @length is non-%NULL then the number of elements in the result is
1970 * stored there. In any case, the resulting array will be
1971 * %NULL-terminated.
1972 *
1973 * For an empty array, @length will be set to 0 and a pointer to a
1974 * %NULL pointer will be returned.
1975 *
1976 * Returns: (array length=length) (transfer full): an array of strings
1977 *
1978 * Since: 2.26
1979 **/
1980 gchar **
1981 g_variant_dup_bytestring_array (GVariant *value,
1982 gsize *length)
1983 {
1984 gchar **strv;
1985 gsize n;
1986 gsize i;
1987
1988 TYPE_CHECK (value, G_VARIANT_TYPE_BYTESTRING_ARRAY, NULL);
1989
1990 g_variant_get_data (value);
1991 n = g_variant_n_children (value);
1992 strv = g_new (gchar *, n + 1);
1993
1994 for (i = 0; i < n; i++)
1995 {
1996 GVariant *string;
1997
1998 string = g_variant_get_child_value (value, i);
1999 strv[i] = g_variant_dup_bytestring (string, NULL);
2000 g_variant_unref (string);
2001 }
2002 strv[i] = NULL;
2003
2004 if (length)
2005 *length = n;
2006
2007 return strv;
2008 }
2009
2010 /* Type checking and querying {{{1 */
2011 /**
2012 * g_variant_get_type:
2013 * @value: a #GVariant
2014 *
2015 * Determines the type of @value.
2016 *
2017 * The return value is valid for the lifetime of @value and must not
2018 * be freed.
2019 *
2020 * Returns: a #GVariantType
2021 *
2022 * Since: 2.24
2023 **/
2024 const GVariantType *
2025 g_variant_get_type (GVariant *value)
2026 {
2027 GVariantTypeInfo *type_info;
2028
2029 g_return_val_if_fail (value != NULL, NULL);
2030
2031 type_info = g_variant_get_type_info (value);
2032
2033 return (GVariantType *) g_variant_type_info_get_type_string (type_info);
2034 }
2035
2036 /**
2037 * g_variant_get_type_string:
2038 * @value: a #GVariant
2039 *
2040 * Returns the type string of @value. Unlike the result of calling
2041 * g_variant_type_peek_string(), this string is nul-terminated. This
2042 * string belongs to #GVariant and must not be freed.
2043 *
2044 * Returns: the type string for the type of @value
2045 *
2046 * Since: 2.24
2047 **/
2048 const gchar *
2049 g_variant_get_type_string (GVariant *value)
2050 {
2051 GVariantTypeInfo *type_info;
2052
2053 g_return_val_if_fail (value != NULL, NULL);
2054
2055 type_info = g_variant_get_type_info (value);
2056
2057 return g_variant_type_info_get_type_string (type_info);
2058 }
2059
2060 /**
2061 * g_variant_is_of_type:
2062 * @value: a #GVariant instance
2063 * @type: a #GVariantType
2064 *
2065 * Checks if a value has a type matching the provided type.
2066 *
2067 * Returns: %TRUE if the type of @value matches @type
2068 *
2069 * Since: 2.24
2070 **/
2071 gboolean
2072 g_variant_is_of_type (GVariant *value,
2073 const GVariantType *type)
2074 {
2075 return g_variant_type_is_subtype_of (g_variant_get_type (value), type);
2076 }
2077
2078 /**
2079 * g_variant_is_container:
2080 * @value: a #GVariant instance
2081 *
2082 * Checks if @value is a container.
2083 *
2084 * Returns: %TRUE if @value is a container
2085 *
2086 * Since: 2.24
2087 */
2088 gboolean
2089 g_variant_is_container (GVariant *value)
2090 {
2091 return g_variant_type_is_container (g_variant_get_type (value));
2092 }
2093
2094
2095 /**
2096 * g_variant_classify:
2097 * @value: a #GVariant
2098 *
2099 * Classifies @value according to its top-level type.
2100 *
2101 * Returns: the #GVariantClass of @value
2102 *
2103 * Since: 2.24
2104 **/
2105 /**
2106 * GVariantClass:
2107 * @G_VARIANT_CLASS_BOOLEAN: The #GVariant is a boolean.
2108 * @G_VARIANT_CLASS_BYTE: The #GVariant is a byte.
2109 * @G_VARIANT_CLASS_INT16: The #GVariant is a signed 16 bit integer.
2110 * @G_VARIANT_CLASS_UINT16: The #GVariant is an unsigned 16 bit integer.
2111 * @G_VARIANT_CLASS_INT32: The #GVariant is a signed 32 bit integer.
2112 * @G_VARIANT_CLASS_UINT32: The #GVariant is an unsigned 32 bit integer.
2113 * @G_VARIANT_CLASS_INT64: The #GVariant is a signed 64 bit integer.
2114 * @G_VARIANT_CLASS_UINT64: The #GVariant is an unsigned 64 bit integer.
2115 * @G_VARIANT_CLASS_HANDLE: The #GVariant is a file handle index.
2116 * @G_VARIANT_CLASS_DOUBLE: The #GVariant is a double precision floating
2117 * point value.
2118 * @G_VARIANT_CLASS_STRING: The #GVariant is a normal string.
2119 * @G_VARIANT_CLASS_OBJECT_PATH: The #GVariant is a D-Bus object path
2120 * string.
2121 * @G_VARIANT_CLASS_SIGNATURE: The #GVariant is a D-Bus signature string.
2122 * @G_VARIANT_CLASS_VARIANT: The #GVariant is a variant.
2123 * @G_VARIANT_CLASS_MAYBE: The #GVariant is a maybe-typed value.
2124 * @G_VARIANT_CLASS_ARRAY: The #GVariant is an array.
2125 * @G_VARIANT_CLASS_TUPLE: The #GVariant is a tuple.
2126 * @G_VARIANT_CLASS_DICT_ENTRY: The #GVariant is a dictionary entry.
2127 *
2128 * The range of possible top-level types of #GVariant instances.
2129 *
2130 * Since: 2.24
2131 **/
2132 GVariantClass
2133 g_variant_classify (GVariant *value)
2134 {
2135 g_return_val_if_fail (value != NULL, 0);
2136
2137 return *g_variant_get_type_string (value);
2138 }
2139
2140 /* Pretty printer {{{1 */
2141 /* This function is not introspectable because if @string is NULL,
2142 @returns is (transfer full), otherwise it is (transfer none), which
2143 is not supported by GObjectIntrospection */
2144 /**
2145 * g_variant_print_string: (skip)
2146 * @value: a #GVariant
2147 * @string: (allow-none) (default NULL): a #GString, or %NULL
2148 * @type_annotate: %TRUE if type information should be included in
2149 * the output
2150 *
2151 * Behaves as g_variant_print(), but operates on a #GString.
2152 *
2153 * If @string is non-%NULL then it is appended to and returned. Else,
2154 * a new empty #GString is allocated and it is returned.
2155 *
2156 * Returns: a #GString containing the string
2157 *
2158 * Since: 2.24
2159 **/
2160 GString *
2161 g_variant_print_string (GVariant *value,
2162 GString *string,
2163 gboolean type_annotate)
2164 {
2165 if G_UNLIKELY (string == NULL)
2166 string = g_string_new (NULL);
2167
2168 switch (g_variant_classify (value))
2169 {
2170 case G_VARIANT_CLASS_MAYBE:
2171 if (type_annotate)
2172 g_string_append_printf (string, "@%s ",
2173 g_variant_get_type_string (value));
2174
2175 if (g_variant_n_children (value))
2176 {
2177 gchar *printed_child;
2178 GVariant *element;
2179
2180 /* Nested maybes:
2181 *
2182 * Consider the case of the type "mmi". In this case we could
2183 * write "just just 4", but "4" alone is totally unambiguous,
2184 * so we try to drop "just" where possible.
2185 *
2186 * We have to be careful not to always drop "just", though,
2187 * since "nothing" needs to be distinguishable from "just
2188 * nothing". The case where we need to ensure we keep the
2189 * "just" is actually exactly the case where we have a nested
2190 * Nothing.
2191 *
2192 * Instead of searching for that nested Nothing, we just print
2193 * the contained value into a separate string and see if we
2194 * end up with "nothing" at the end of it. If so, we need to
2195 * add "just" at our level.
2196 */
2197 element = g_variant_get_child_value (value, 0);
2198 printed_child = g_variant_print (element, FALSE);
2199 g_variant_unref (element);
2200
2201 if (g_str_has_suffix (printed_child, "nothing"))
2202 g_string_append (string, "just ");
2203 g_string_append (string, printed_child);
2204 g_free (printed_child);
2205 }
2206 else
2207 g_string_append (string, "nothing");
2208
2209 break;
2210
2211 case G_VARIANT_CLASS_ARRAY:
2212 /* it's an array so the first character of the type string is 'a'
2213 *
2214 * if the first two characters are 'ay' then it's a bytestring.
2215 * under certain conditions we print those as strings.
2216 */
2217 if (g_variant_get_type_string (value)[1] == 'y')
2218 {
2219 const gchar *str;
2220 gsize size;
2221 gsize i;
2222
2223 /* first determine if it is a byte string.
2224 * that's when there's a single nul character: at the end.
2225 */
2226 str = g_variant_get_data (value);
2227 size = g_variant_get_size (value);
2228
2229 for (i = 0; i < size; i++)
2230 if (str[i] == '\0')
2231 break;
2232
2233 /* first nul byte is the last byte -> it's a byte string. */
2234 if (i == size - 1)
2235 {
2236 gchar *escaped = g_strescape (str, NULL);
2237
2238 /* use double quotes only if a ' is in the string */
2239 if (strchr (str, '\''))
2240 g_string_append_printf (string, "b\"%s\"", escaped);
2241 else
2242 g_string_append_printf (string, "b'%s'", escaped);
2243
2244 g_free (escaped);
2245 break;
2246 }
2247
2248 else
2249 /* fall through and handle normally... */;
2250 }
2251
2252 /*
2253 * if the first two characters are 'a{' then it's an array of
2254 * dictionary entries (ie: a dictionary) so we print that
2255 * differently.
2256 */
2257 if (g_variant_get_type_string (value)[1] == '{')
2258 /* dictionary */
2259 {
2260 const gchar *comma = "";
2261 gsize n, i;
2262
2263 if ((n = g_variant_n_children (value)) == 0)
2264 {
2265 if (type_annotate)
2266 g_string_append_printf (string, "@%s ",
2267 g_variant_get_type_string (value));
2268 g_string_append (string, "{}");
2269 break;
2270 }
2271
2272 g_string_append_c (string, '{');
2273 for (i = 0; i < n; i++)
2274 {
2275 GVariant *entry, *key, *val;
2276
2277 g_string_append (string, comma);
2278 comma = ", ";
2279
2280 entry = g_variant_get_child_value (value, i);
2281 key = g_variant_get_child_value (entry, 0);
2282 val = g_variant_get_child_value (entry, 1);
2283 g_variant_unref (entry);
2284
2285 g_variant_print_string (key, string, type_annotate);
2286 g_variant_unref (key);
2287 g_string_append (string, ": ");
2288 g_variant_print_string (val, string, type_annotate);
2289 g_variant_unref (val);
2290 type_annotate = FALSE;
2291 }
2292 g_string_append_c (string, '}');
2293 }
2294 else
2295 /* normal (non-dictionary) array */
2296 {
2297 const gchar *comma = "";
2298 gsize n, i;
2299
2300 if ((n = g_variant_n_children (value)) == 0)
2301 {
2302 if (type_annotate)
2303 g_string_append_printf (string, "@%s ",
2304 g_variant_get_type_string (value));
2305 g_string_append (string, "[]");
2306 break;
2307 }
2308
2309 g_string_append_c (string, '[');
2310 for (i = 0; i < n; i++)
2311 {
2312 GVariant *element;
2313
2314 g_string_append (string, comma);
2315 comma = ", ";
2316
2317 element = g_variant_get_child_value (value, i);
2318
2319 g_variant_print_string (element, string, type_annotate);
2320 g_variant_unref (element);
2321 type_annotate = FALSE;
2322 }
2323 g_string_append_c (string, ']');
2324 }
2325
2326 break;
2327
2328 case G_VARIANT_CLASS_TUPLE:
2329 {
2330 gsize n, i;
2331
2332 n = g_variant_n_children (value);
2333
2334 g_string_append_c (string, '(');
2335 for (i = 0; i < n; i++)
2336 {
2337 GVariant *element;
2338
2339 element = g_variant_get_child_value (value, i);
2340 g_variant_print_string (element, string, type_annotate);
2341 g_string_append (string, ", ");
2342 g_variant_unref (element);
2343 }
2344
2345 /* for >1 item: remove final ", "
2346 * for 1 item: remove final " ", but leave the ","
2347 * for 0 items: there is only "(", so remove nothing
2348 */
2349 g_string_truncate (string, string->len - (n > 0) - (n > 1));
2350 g_string_append_c (string, ')');
2351 }
2352 break;
2353
2354 case G_VARIANT_CLASS_DICT_ENTRY:
2355 {
2356 GVariant *element;
2357
2358 g_string_append_c (string, '{');
2359
2360 element = g_variant_get_child_value (value, 0);
2361 g_variant_print_string (element, string, type_annotate);
2362 g_variant_unref (element);
2363
2364 g_string_append (string, ", ");
2365
2366 element = g_variant_get_child_value (value, 1);
2367 g_variant_print_string (element, string, type_annotate);
2368 g_variant_unref (element);
2369
2370 g_string_append_c (string, '}');
2371 }
2372 break;
2373
2374 case G_VARIANT_CLASS_VARIANT:
2375 {
2376 GVariant *child = g_variant_get_variant (value);
2377
2378 /* Always annotate types in nested variants, because they are
2379 * (by nature) of variable type.
2380 */
2381 g_string_append_c (string, '<');
2382 g_variant_print_string (child, string, TRUE);
2383 g_string_append_c (string, '>');
2384
2385 g_variant_unref (child);
2386 }
2387 break;
2388
2389 case G_VARIANT_CLASS_BOOLEAN:
2390 if (g_variant_get_boolean (value))
2391 g_string_append (string, "true");
2392 else
2393 g_string_append (string, "false");
2394 break;
2395
2396 case G_VARIANT_CLASS_STRING:
2397 {
2398 const gchar *str = g_variant_get_string (value, NULL);
2399 gunichar quote = strchr (str, '\'') ? '"' : '\'';
2400
2401 g_string_append_c (string, quote);
2402
2403 while (*str)
2404 {
2405 gunichar c = g_utf8_get_char (str);
2406
2407 if (c == quote || c == '\\')
2408 g_string_append_c (string, '\\');
2409
2410 if (g_unichar_isprint (c))
2411 g_string_append_unichar (string, c);
2412
2413 else
2414 {
2415 g_string_append_c (string, '\\');
2416 if (c < 0x10000)
2417 switch (c)
2418 {
2419 case '\a':
2420 g_string_append_c (string, 'a');
2421 break;
2422
2423 case '\b':
2424 g_string_append_c (string, 'b');
2425 break;
2426
2427 case '\f':
2428 g_string_append_c (string, 'f');
2429 break;
2430
2431 case '\n':
2432 g_string_append_c (string, 'n');
2433 break;
2434
2435 case '\r':
2436 g_string_append_c (string, 'r');
2437 break;
2438
2439 case '\t':
2440 g_string_append_c (string, 't');
2441 break;
2442
2443 case '\v':
2444 g_string_append_c (string, 'v');
2445 break;
2446
2447 default:
2448 g_string_append_printf (string, "u%04x", c);
2449 break;
2450 }
2451 else
2452 g_string_append_printf (string, "U%08x", c);
2453 }
2454
2455 str = g_utf8_next_char (str);
2456 }
2457
2458 g_string_append_c (string, quote);
2459 }
2460 break;
2461
2462 case G_VARIANT_CLASS_BYTE:
2463 if (type_annotate)
2464 g_string_append (string, "byte ");
2465 g_string_append_printf (string, "0x%02x",
2466 g_variant_get_byte (value));
2467 break;
2468
2469 case G_VARIANT_CLASS_INT16:
2470 if (type_annotate)
2471 g_string_append (string, "int16 ");
2472 g_string_append_printf (string, "%"G_GINT16_FORMAT,
2473 g_variant_get_int16 (value));
2474 break;
2475
2476 case G_VARIANT_CLASS_UINT16:
2477 if (type_annotate)
2478 g_string_append (string, "uint16 ");
2479 g_string_append_printf (string, "%"G_GUINT16_FORMAT,
2480 g_variant_get_uint16 (value));
2481 break;
2482
2483 case G_VARIANT_CLASS_INT32:
2484 /* Never annotate this type because it is the default for numbers
2485 * (and this is a *pretty* printer)
2486 */
2487 g_string_append_printf (string, "%"G_GINT32_FORMAT,
2488 g_variant_get_int32 (value));
2489 break;
2490
2491 case G_VARIANT_CLASS_HANDLE:
2492 if (type_annotate)
2493 g_string_append (string, "handle ");
2494 g_string_append_printf (string, "%"G_GINT32_FORMAT,
2495 g_variant_get_handle (value));
2496 break;
2497
2498 case G_VARIANT_CLASS_UINT32:
2499 if (type_annotate)
2500 g_string_append (string, "uint32 ");
2501 g_string_append_printf (string, "%"G_GUINT32_FORMAT,
2502 g_variant_get_uint32 (value));
2503 break;
2504
2505 case G_VARIANT_CLASS_INT64:
2506 if (type_annotate)
2507 g_string_append (string, "int64 ");
2508 g_string_append_printf (string, "%"G_GINT64_FORMAT,
2509 g_variant_get_int64 (value));
2510 break;
2511
2512 case G_VARIANT_CLASS_UINT64:
2513 if (type_annotate)
2514 g_string_append (string, "uint64 ");
2515 g_string_append_printf (string, "%"G_GUINT64_FORMAT,
2516 g_variant_get_uint64 (value));
2517 break;
2518
2519 case G_VARIANT_CLASS_DOUBLE:
2520 {
2521 gchar buffer[100];
2522 gint i;
2523
2524 g_ascii_dtostr (buffer, sizeof buffer, g_variant_get_double (value));
2525
2526 for (i = 0; buffer[i]; i++)
2527 if (buffer[i] == '.' || buffer[i] == 'e' ||
2528 buffer[i] == 'n' || buffer[i] == 'N')
2529 break;
2530
2531 /* if there is no '.' or 'e' in the float then add one */
2532 if (buffer[i] == '\0')
2533 {
2534 buffer[i++] = '.';
2535 buffer[i++] = '0';
2536 buffer[i++] = '\0';
2537 }
2538
2539 g_string_append (string, buffer);
2540 }
2541 break;
2542
2543 case G_VARIANT_CLASS_OBJECT_PATH:
2544 if (type_annotate)
2545 g_string_append (string, "objectpath ");
2546 g_string_append_printf (string, "\'%s\'",
2547 g_variant_get_string (value, NULL));
2548 break;
2549
2550 case G_VARIANT_CLASS_SIGNATURE:
2551 if (type_annotate)
2552 g_string_append (string, "signature ");
2553 g_string_append_printf (string, "\'%s\'",
2554 g_variant_get_string (value, NULL));
2555 break;
2556
2557 default:
2558 g_assert_not_reached ();
2559 }
2560
2561 return string;
2562 }
2563
2564 /**
2565 * g_variant_print:
2566 * @value: a #GVariant
2567 * @type_annotate: %TRUE if type information should be included in
2568 * the output
2569 *
2570 * Pretty-prints @value in the format understood by g_variant_parse().
2571 *
2572 * The format is described [here][gvariant-text].
2573 *
2574 * If @type_annotate is %TRUE, then type information is included in
2575 * the output.
2576 *
2577 * Returns: (transfer full): a newly-allocated string holding the result.
2578 *
2579 * Since: 2.24
2580 */
2581 gchar *
2582 g_variant_print (GVariant *value,
2583 gboolean type_annotate)
2584 {
2585 return g_string_free (g_variant_print_string (value, NULL, type_annotate),
2586 FALSE);
2587 };
2588
2589 /* Hash, Equal, Compare {{{1 */
2590 /**
2591 * g_variant_hash:
2592 * @value: (type GVariant): a basic #GVariant value as a #gconstpointer
2593 *
2594 * Generates a hash value for a #GVariant instance.
2595 *
2596 * The output of this function is guaranteed to be the same for a given
2597 * value only per-process. It may change between different processor
2598 * architectures or even different versions of GLib. Do not use this
2599 * function as a basis for building protocols or file formats.
2600 *
2601 * The type of @value is #gconstpointer only to allow use of this
2602 * function with #GHashTable. @value must be a #GVariant.
2603 *
2604 * Returns: a hash value corresponding to @value
2605 *
2606 * Since: 2.24
2607 **/
2608 guint
2609 g_variant_hash (gconstpointer value_)
2610 {
2611 GVariant *value = (GVariant *) value_;
2612
2613 switch (g_variant_classify (value))
2614 {
2615 case G_VARIANT_CLASS_STRING:
2616 case G_VARIANT_CLASS_OBJECT_PATH:
2617 case G_VARIANT_CLASS_SIGNATURE:
2618 return g_str_hash (g_variant_get_string (value, NULL));
2619
2620 case G_VARIANT_CLASS_BOOLEAN:
2621 /* this is a very odd thing to hash... */
2622 return g_variant_get_boolean (value);
2623
2624 case G_VARIANT_CLASS_BYTE:
2625 return g_variant_get_byte (value);
2626
2627 case G_VARIANT_CLASS_INT16:
2628 case G_VARIANT_CLASS_UINT16:
2629 {
2630 const guint16 *ptr;
2631
2632 ptr = g_variant_get_data (value);
2633
2634 if (ptr)
2635 return *ptr;
2636 else
2637 return 0;
2638 }
2639
2640 case G_VARIANT_CLASS_INT32:
2641 case G_VARIANT_CLASS_UINT32:
2642 case G_VARIANT_CLASS_HANDLE:
2643 {
2644 const guint *ptr;
2645
2646 ptr = g_variant_get_data (value);
2647
2648 if (ptr)
2649 return *ptr;
2650 else
2651 return 0;
2652 }
2653
2654 case G_VARIANT_CLASS_INT64:
2655 case G_VARIANT_CLASS_UINT64:
2656 case G_VARIANT_CLASS_DOUBLE:
2657 /* need a separate case for these guys because otherwise
2658 * performance could be quite bad on big endian systems
2659 */
2660 {
2661 const guint *ptr;
2662
2663 ptr = g_variant_get_data (value);
2664
2665 if (ptr)
2666 return ptr[0] + ptr[1];
2667 else
2668 return 0;
2669 }
2670
2671 default:
2672 g_return_val_if_fail (!g_variant_is_container (value), 0);
2673 g_assert_not_reached ();
2674 }
2675 }
2676
2677 /**
2678 * g_variant_equal:
2679 * @one: (type GVariant): a #GVariant instance
2680 * @two: (type GVariant): a #GVariant instance
2681 *
2682 * Checks if @one and @two have the same type and value.
2683 *
2684 * The types of @one and @two are #gconstpointer only to allow use of
2685 * this function with #GHashTable. They must each be a #GVariant.
2686 *
2687 * Returns: %TRUE if @one and @two are equal
2688 *
2689 * Since: 2.24
2690 **/
2691 gboolean
2692 g_variant_equal (gconstpointer one,
2693 gconstpointer two)
2694 {
2695 gboolean equal;
2696
2697 g_return_val_if_fail (one != NULL && two != NULL, FALSE);
2698
2699 if (g_variant_get_type_info ((GVariant *) one) !=
2700 g_variant_get_type_info ((GVariant *) two))
2701 return FALSE;
2702
2703 /* if both values are trusted to be in their canonical serialised form
2704 * then a simple memcmp() of their serialised data will answer the
2705 * question.
2706 *
2707 * if not, then this might generate a false negative (since it is
2708 * possible for two different byte sequences to represent the same
2709 * value). for now we solve this by pretty-printing both values and
2710 * comparing the result.
2711 */
2712 if (g_variant_is_trusted ((GVariant *) one) &&
2713 g_variant_is_trusted ((GVariant *) two))
2714 {
2715 gconstpointer data_one, data_two;
2716 gsize size_one, size_two;
2717
2718 size_one = g_variant_get_size ((GVariant *) one);
2719 size_two = g_variant_get_size ((GVariant *) two);
2720
2721 if (size_one != size_two)
2722 return FALSE;
2723
2724 data_one = g_variant_get_data ((GVariant *) one);
2725 data_two = g_variant_get_data ((GVariant *) two);
2726
2727 equal = memcmp (data_one, data_two, size_one) == 0;
2728 }
2729 else
2730 {
2731 gchar *strone, *strtwo;
2732
2733 strone = g_variant_print ((GVariant *) one, FALSE);
2734 strtwo = g_variant_print ((GVariant *) two, FALSE);
2735 equal = strcmp (strone, strtwo) == 0;
2736 g_free (strone);
2737 g_free (strtwo);
2738 }
2739
2740 return equal;
2741 }
2742
2743 /**
2744 * g_variant_compare:
2745 * @one: (type GVariant): a basic-typed #GVariant instance
2746 * @two: (type GVariant): a #GVariant instance of the same type
2747 *
2748 * Compares @one and @two.
2749 *
2750 * The types of @one and @two are #gconstpointer only to allow use of
2751 * this function with #GTree, #GPtrArray, etc. They must each be a
2752 * #GVariant.
2753 *
2754 * Comparison is only defined for basic types (ie: booleans, numbers,
2755 * strings). For booleans, %FALSE is less than %TRUE. Numbers are
2756 * ordered in the usual way. Strings are in ASCII lexographical order.
2757 *
2758 * It is a programmer error to attempt to compare container values or
2759 * two values that have types that are not exactly equal. For example,
2760 * you cannot compare a 32-bit signed integer with a 32-bit unsigned
2761 * integer. Also note that this function is not particularly
2762 * well-behaved when it comes to comparison of doubles; in particular,
2763 * the handling of incomparable values (ie: NaN) is undefined.
2764 *
2765 * If you only require an equality comparison, g_variant_equal() is more
2766 * general.
2767 *
2768 * Returns: negative value if a < b;
2769 * zero if a = b;
2770 * positive value if a > b.
2771 *
2772 * Since: 2.26
2773 **/
2774 gint
2775 g_variant_compare (gconstpointer one,
2776 gconstpointer two)
2777 {
2778 GVariant *a = (GVariant *) one;
2779 GVariant *b = (GVariant *) two;
2780
2781 g_return_val_if_fail (g_variant_classify (a) == g_variant_classify (b), 0);
2782
2783 switch (g_variant_classify (a))
2784 {
2785 case G_VARIANT_CLASS_BOOLEAN:
2786 return g_variant_get_boolean (a) -
2787 g_variant_get_boolean (b);
2788
2789 case G_VARIANT_CLASS_BYTE:
2790 return ((gint) g_variant_get_byte (a)) -
2791 ((gint) g_variant_get_byte (b));
2792
2793 case G_VARIANT_CLASS_INT16:
2794 return ((gint) g_variant_get_int16 (a)) -
2795 ((gint) g_variant_get_int16 (b));
2796
2797 case G_VARIANT_CLASS_UINT16:
2798 return ((gint) g_variant_get_uint16 (a)) -
2799 ((gint) g_variant_get_uint16 (b));
2800
2801 case G_VARIANT_CLASS_INT32:
2802 {
2803 gint32 a_val = g_variant_get_int32 (a);
2804 gint32 b_val = g_variant_get_int32 (b);
2805
2806 return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
2807 }
2808
2809 case G_VARIANT_CLASS_UINT32:
2810 {
2811 guint32 a_val = g_variant_get_uint32 (a);
2812 guint32 b_val = g_variant_get_uint32 (b);
2813
2814 return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
2815 }
2816
2817 case G_VARIANT_CLASS_INT64:
2818 {
2819 gint64 a_val = g_variant_get_int64 (a);
2820 gint64 b_val = g_variant_get_int64 (b);
2821
2822 return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
2823 }
2824
2825 case G_VARIANT_CLASS_UINT64:
2826 {
2827 guint64 a_val = g_variant_get_uint64 (a);
2828 guint64 b_val = g_variant_get_uint64 (b);
2829
2830 return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
2831 }
2832
2833 case G_VARIANT_CLASS_DOUBLE:
2834 {
2835 gdouble a_val = g_variant_get_double (a);
2836 gdouble b_val = g_variant_get_double (b);
2837
2838 return (a_val == b_val) ? 0 : (a_val > b_val) ? 1 : -1;
2839 }
2840
2841 case G_VARIANT_CLASS_STRING:
2842 case G_VARIANT_CLASS_OBJECT_PATH:
2843 case G_VARIANT_CLASS_SIGNATURE:
2844 return strcmp (g_variant_get_string (a, NULL),
2845 g_variant_get_string (b, NULL));
2846
2847 default:
2848 g_return_val_if_fail (!g_variant_is_container (a), 0);
2849 g_assert_not_reached ();
2850 }
2851 }
2852
2853 /* GVariantIter {{{1 */
2854 /**
2855 * GVariantIter: (skip)
2856 *
2857 * #GVariantIter is an opaque data structure and can only be accessed
2858 * using the following functions.
2859 **/
2860 struct stack_iter
2861 {
2862 GVariant *value;
2863 gssize n, i;
2864
2865 const gchar *loop_format;
2866
2867 gsize padding[3];
2868 gsize magic;
2869 };
2870
2871 G_STATIC_ASSERT (sizeof (struct stack_iter) <= sizeof (GVariantIter));
2872
2873 struct heap_iter
2874 {
2875 struct stack_iter iter;
2876
2877 GVariant *value_ref;
2878 gsize magic;
2879 };
2880
2881 #define GVSI(i) ((struct stack_iter *) (i))
2882 #define GVHI(i) ((struct heap_iter *) (i))
2883 #define GVSI_MAGIC ((gsize) 3579507750u)
2884 #define GVHI_MAGIC ((gsize) 1450270775u)
2885 #define is_valid_iter(i) (i != NULL && \
2886 GVSI(i)->magic == GVSI_MAGIC)
2887 #define is_valid_heap_iter(i) (GVHI(i)->magic == GVHI_MAGIC && \
2888 is_valid_iter(i))
2889
2890 /**
2891 * g_variant_iter_new:
2892 * @value: a container #GVariant
2893 *
2894 * Creates a heap-allocated #GVariantIter for iterating over the items
2895 * in @value.
2896 *
2897 * Use g_variant_iter_free() to free the return value when you no longer
2898 * need it.
2899 *
2900 * A reference is taken to @value and will be released only when
2901 * g_variant_iter_free() is called.
2902 *
2903 * Returns: (transfer full): a new heap-allocated #GVariantIter
2904 *
2905 * Since: 2.24
2906 **/
2907 GVariantIter *
2908 g_variant_iter_new (GVariant *value)
2909 {
2910 GVariantIter *iter;
2911
2912 iter = (GVariantIter *) g_slice_new (struct heap_iter);
2913 #ifdef GSTREAMER_LITE
2914 if (iter == NULL) {
2915 return NULL;
2916 }
2917 #endif // GSTREAMER_LITE
2918 GVHI(iter)->value_ref = g_variant_ref (value);
2919 GVHI(iter)->magic = GVHI_MAGIC;
2920
2921 g_variant_iter_init (iter, value);
2922
2923 return iter;
2924 }
2925
2926 /**
2927 * g_variant_iter_init: (skip)
2928 * @iter: a pointer to a #GVariantIter
2929 * @value: a container #GVariant
2930 *
2931 * Initialises (without allocating) a #GVariantIter. @iter may be
2932 * completely uninitialised prior to this call; its old value is
2933 * ignored.
2934 *
2935 * The iterator remains valid for as long as @value exists, and need not
2936 * be freed in any way.
2937 *
2938 * Returns: the number of items in @value
2939 *
2940 * Since: 2.24
2941 **/
2942 gsize
2943 g_variant_iter_init (GVariantIter *iter,
2944 GVariant *value)
2945 {
2946 GVSI(iter)->magic = GVSI_MAGIC;
2947 GVSI(iter)->value = value;
2948 GVSI(iter)->n = g_variant_n_children (value);
2949 GVSI(iter)->i = -1;
2950 GVSI(iter)->loop_format = NULL;
2951
2952 return GVSI(iter)->n;
2953 }
2954
2955 /**
2956 * g_variant_iter_copy:
2957 * @iter: a #GVariantIter
2958 *
2959 * Creates a new heap-allocated #GVariantIter to iterate over the
2960 * container that was being iterated over by @iter. Iteration begins on
2961 * the new iterator from the current position of the old iterator but
2962 * the two copies are independent past that point.
2963 *
2964 * Use g_variant_iter_free() to free the return value when you no longer
2965 * need it.
2966 *
2967 * A reference is taken to the container that @iter is iterating over
2968 * and will be releated only when g_variant_iter_free() is called.
2969 *
2970 * Returns: (transfer full): a new heap-allocated #GVariantIter
2971 *
2972 * Since: 2.24
2973 **/
2974 GVariantIter *
2975 g_variant_iter_copy (GVariantIter *iter)
2976 {
2977 GVariantIter *copy;
2978
2979 #ifdef GSTREAMER_LITE
2980 if (iter == NULL) {
2981 return NULL;
2982 }
2983 #endif // GSTREAMER_LITE
2984
2985 g_return_val_if_fail (is_valid_iter (iter), 0);
2986
2987 copy = g_variant_iter_new (GVSI(iter)->value);
2988 GVSI(copy)->i = GVSI(iter)->i;
2989
2990 return copy;
2991 }
2992
2993 /**
2994 * g_variant_iter_n_children:
2995 * @iter: a #GVariantIter
2996 *
2997 * Queries the number of child items in the container that we are
2998 * iterating over. This is the total number of items -- not the number
2999 * of items remaining.
3000 *
3001 * This function might be useful for preallocation of arrays.
3002 *
3003 * Returns: the number of children in the container
3004 *
3005 * Since: 2.24
3006 **/
3007 gsize
3008 g_variant_iter_n_children (GVariantIter *iter)
3009 {
3010 g_return_val_if_fail (is_valid_iter (iter), 0);
3011
3012 return GVSI(iter)->n;
3013 }
3014
3015 /**
3016 * g_variant_iter_free:
3017 * @iter: (transfer full): a heap-allocated #GVariantIter
3018 *
3019 * Frees a heap-allocated #GVariantIter. Only call this function on
3020 * iterators that were returned by g_variant_iter_new() or
3021 * g_variant_iter_copy().
3022 *
3023 * Since: 2.24
3024 **/
3025 void
3026 g_variant_iter_free (GVariantIter *iter)
3027 {
3028 g_return_if_fail (is_valid_heap_iter (iter));
3029
3030 g_variant_unref (GVHI(iter)->value_ref);
3031 GVHI(iter)->magic = 0;
3032
3033 g_slice_free (struct heap_iter, GVHI(iter));
3034 }
3035
3036 /**
3037 * g_variant_iter_next_value:
3038 * @iter: a #GVariantIter
3039 *
3040 * Gets the next item in the container. If no more items remain then
3041 * %NULL is returned.
3042 *
3043 * Use g_variant_unref() to drop your reference on the return value when
3044 * you no longer need it.
3045 *
3046 * Here is an example for iterating with g_variant_iter_next_value():
3047 * |[<!-- language="C" -->
3048 * // recursively iterate a container
3049 * void
3050 * iterate_container_recursive (GVariant *container)
3051 * {
3052 * GVariantIter iter;
3053 * GVariant *child;
3054 *
3055 * g_variant_iter_init (&iter, container);
3056 * while ((child = g_variant_iter_next_value (&iter)))
3057 * {
3058 * g_print ("type '%s'\n", g_variant_get_type_string (child));
3059 *
3060 * if (g_variant_is_container (child))
3061 * iterate_container_recursive (child);
3062 *
3063 * g_variant_unref (child);
3064 * }
3065 * }
3066 * ]|
3067 *
3068 * Returns: (allow-none) (transfer full): a #GVariant, or %NULL
3069 *
3070 * Since: 2.24
3071 **/
3072 GVariant *
3073 g_variant_iter_next_value (GVariantIter *iter)
3074 {
3075 g_return_val_if_fail (is_valid_iter (iter), FALSE);
3076
3077 if G_UNLIKELY (GVSI(iter)->i >= GVSI(iter)->n)
3078 {
3079 g_critical ("g_variant_iter_next_value: must not be called again "
3080 "after NULL has already been returned.");
3081 return NULL;
3082 }
3083
3084 GVSI(iter)->i++;
3085
3086 if (GVSI(iter)->i < GVSI(iter)->n)
3087 return g_variant_get_child_value (GVSI(iter)->value, GVSI(iter)->i);
3088
3089 return NULL;
3090 }
3091
3092 /* GVariantBuilder {{{1 */
3093 /**
3094 * GVariantBuilder:
3095 *
3096 * A utility type for constructing container-type #GVariant instances.
3097 *
3098 * This is an opaque structure and may only be accessed using the
3099 * following functions.
3100 *
3101 * #GVariantBuilder is not threadsafe in any way. Do not attempt to
3102 * access it from more than one thread.
3103 **/
3104
3105 struct stack_builder
3106 {
3107 GVariantBuilder *parent;
3108 GVariantType *type;
3109
3110 /* type constraint explicitly specified by 'type'.
3111 * for tuple types, this moves along as we add more items.
3112 */
3113 const GVariantType *expected_type;
3114
3115 /* type constraint implied by previous array item.
3116 */
3117 const GVariantType *prev_item_type;
3118
3119 /* constraints on the number of children. max = -1 for unlimited. */
3120 gsize min_items;
3121 gsize max_items;
3122
3123 /* dynamically-growing pointer array */
3124 GVariant **children;
3125 gsize allocated_children;
3126 gsize offset;
3127
3128 /* set to '1' if all items in the container will have the same type
3129 * (ie: maybe, array, variant) '0' if not (ie: tuple, dict entry)
3130 */
3131 guint uniform_item_types : 1;
3132
3133 /* set to '1' initially and changed to '0' if an untrusted value is
3134 * added
3135 */
3136 guint trusted : 1;
3137
3138 gsize magic;
3139 };
3140
3141 G_STATIC_ASSERT (sizeof (struct stack_builder) <= sizeof (GVariantBuilder));
3142
3143 struct heap_builder
3144 {
3145 GVariantBuilder builder;
3146 gsize magic;
3147
3148 gint ref_count;
3149 };
3150
3151 #define GVSB(b) ((struct stack_builder *) (b))
3152 #define GVHB(b) ((struct heap_builder *) (b))
3153 #define GVSB_MAGIC ((gsize) 1033660112u)
3154 #define GVHB_MAGIC ((gsize) 3087242682u)
3155 #define is_valid_builder(b) (b != NULL && \
3156 GVSB(b)->magic == GVSB_MAGIC)
3157 #define is_valid_heap_builder(b) (GVHB(b)->magic == GVHB_MAGIC)
3158
3159 /**
3160 * g_variant_builder_new:
3161 * @type: a container type
3162 *
3163 * Allocates and initialises a new #GVariantBuilder.
3164 *
3165 * You should call g_variant_builder_unref() on the return value when it
3166 * is no longer needed. The memory will not be automatically freed by
3167 * any other call.
3168 *
3169 * In most cases it is easier to place a #GVariantBuilder directly on
3170 * the stack of the calling function and initialise it with
3171 * g_variant_builder_init().
3172 *
3173 * Returns: (transfer full): a #GVariantBuilder
3174 *
3175 * Since: 2.24
3176 **/
3177 GVariantBuilder *
3178 g_variant_builder_new (const GVariantType *type)
3179 {
3180 GVariantBuilder *builder;
3181
3182 builder = (GVariantBuilder *) g_slice_new (struct heap_builder);
3183 #ifdef GSTREAMER_LITE
3184 if (builder == NULL) {
3185 return NULL;
3186 }
3187 #endif // GSTREAMER_LITE
3188 g_variant_builder_init (builder, type);
3189 GVHB(builder)->magic = GVHB_MAGIC;
3190 GVHB(builder)->ref_count = 1;
3191
3192 return builder;
3193 }
3194
3195 /**
3196 * g_variant_builder_unref:
3197 * @builder: (transfer full): a #GVariantBuilder allocated by g_variant_builder_new()
3198 *
3199 * Decreases the reference count on @builder.
3200 *
3201 * In the event that there are no more references, releases all memory
3202 * associated with the #GVariantBuilder.
3203 *
3204 * Don't call this on stack-allocated #GVariantBuilder instances or bad
3205 * things will happen.
3206 *
3207 * Since: 2.24
3208 **/
3209 void
3210 g_variant_builder_unref (GVariantBuilder *builder)
3211 {
3212 g_return_if_fail (is_valid_heap_builder (builder));
3213
3214 if (--GVHB(builder)->ref_count)
3215 return;
3216
3217 g_variant_builder_clear (builder);
3218 GVHB(builder)->magic = 0;
3219
3220 g_slice_free (struct heap_builder, GVHB(builder));
3221 }
3222
3223 /**
3224 * g_variant_builder_ref:
3225 * @builder: a #GVariantBuilder allocated by g_variant_builder_new()
3226 *
3227 * Increases the reference count on @builder.
3228 *
3229 * Don't call this on stack-allocated #GVariantBuilder instances or bad
3230 * things will happen.
3231 *
3232 * Returns: (transfer full): a new reference to @builder
3233 *
3234 * Since: 2.24
3235 **/
3236 GVariantBuilder *
3237 g_variant_builder_ref (GVariantBuilder *builder)
3238 {
3239 g_return_val_if_fail (is_valid_heap_builder (builder), NULL);
3240
3241 GVHB(builder)->ref_count++;
3242
3243 return builder;
3244 }
3245
3246 /**
3247 * g_variant_builder_clear: (skip)
3248 * @builder: a #GVariantBuilder
3249 *
3250 * Releases all memory associated with a #GVariantBuilder without
3251 * freeing the #GVariantBuilder structure itself.
3252 *
3253 * It typically only makes sense to do this on a stack-allocated
3254 * #GVariantBuilder if you want to abort building the value part-way
3255 * through. This function need not be called if you call
3256 * g_variant_builder_end() and it also doesn't need to be called on
3257 * builders allocated with g_variant_builder_new (see
3258 * g_variant_builder_unref() for that).
3259 *
3260 * This function leaves the #GVariantBuilder structure set to all-zeros.
3261 * It is valid to call this function on either an initialised
3262 * #GVariantBuilder or one that is set to all-zeros but it is not valid
3263 * to call this function on uninitialised memory.
3264 *
3265 * Since: 2.24
3266 **/
3267 void
3268 g_variant_builder_clear (GVariantBuilder *builder)
3269 {
3270 gsize i;
3271
3272 if (GVSB(builder)->magic == 0)
3273 /* all-zeros case */
3274 return;
3275
3276 g_return_if_fail (is_valid_builder (builder));
3277
3278 g_variant_type_free (GVSB(builder)->type);
3279
3280 for (i = 0; i < GVSB(builder)->offset; i++)
3281 g_variant_unref (GVSB(builder)->children[i]);
3282
3283 g_free (GVSB(builder)->children);
3284
3285 if (GVSB(builder)->parent)
3286 {
3287 g_variant_builder_clear (GVSB(builder)->parent);
3288 g_slice_free (GVariantBuilder, GVSB(builder)->parent);
3289 }
3290
3291 memset (builder, 0, sizeof (GVariantBuilder));
3292 }
3293
3294 /**
3295 * g_variant_builder_init: (skip)
3296 * @builder: a #GVariantBuilder
3297 * @type: a container type
3298 *
3299 * Initialises a #GVariantBuilder structure.
3300 *
3301 * @type must be non-%NULL. It specifies the type of container to
3302 * construct. It can be an indefinite type such as
3303 * %G_VARIANT_TYPE_ARRAY or a definite type such as "as" or "(ii)".
3304 * Maybe, array, tuple, dictionary entry and variant-typed values may be
3305 * constructed.
3306 *
3307 * After the builder is initialised, values are added using
3308 * g_variant_builder_add_value() or g_variant_builder_add().
3309 *
3310 * After all the child values are added, g_variant_builder_end() frees
3311 * the memory associated with the builder and returns the #GVariant that
3312 * was created.
3313 *
3314 * This function completely ignores the previous contents of @builder.
3315 * On one hand this means that it is valid to pass in completely
3316 * uninitialised memory. On the other hand, this means that if you are
3317 * initialising over top of an existing #GVariantBuilder you need to
3318 * first call g_variant_builder_clear() in order to avoid leaking
3319 * memory.
3320 *
3321 * You must not call g_variant_builder_ref() or
3322 * g_variant_builder_unref() on a #GVariantBuilder that was initialised
3323 * with this function. If you ever pass a reference to a
3324 * #GVariantBuilder outside of the control of your own code then you
3325 * should assume that the person receiving that reference may try to use
3326 * reference counting; you should use g_variant_builder_new() instead of
3327 * this function.
3328 *
3329 * Since: 2.24
3330 **/
3331 void
3332 g_variant_builder_init (GVariantBuilder *builder,
3333 const GVariantType *type)
3334 {
3335 g_return_if_fail (type != NULL);
3336 g_return_if_fail (g_variant_type_is_container (type));
3337
3338 memset (builder, 0, sizeof (GVariantBuilder));
3339
3340 GVSB(builder)->type = g_variant_type_copy (type);
3341 GVSB(builder)->magic = GVSB_MAGIC;
3342 GVSB(builder)->trusted = TRUE;
3343
3344 switch (*(const gchar *) type)
3345 {
3346 case G_VARIANT_CLASS_VARIANT:
3347 GVSB(builder)->uniform_item_types = TRUE;
3348 GVSB(builder)->allocated_children = 1;
3349 GVSB(builder)->expected_type = NULL;
3350 GVSB(builder)->min_items = 1;
3351 GVSB(builder)->max_items = 1;
3352 break;
3353
3354 case G_VARIANT_CLASS_ARRAY:
3355 GVSB(builder)->uniform_item_types = TRUE;
3356 GVSB(builder)->allocated_children = 8;
3357 GVSB(builder)->expected_type =
3358 g_variant_type_element (GVSB(builder)->type);
3359 GVSB(builder)->min_items = 0;
3360 GVSB(builder)->max_items = -1;
3361 break;
3362
3363 case G_VARIANT_CLASS_MAYBE:
3364 GVSB(builder)->uniform_item_types = TRUE;
3365 GVSB(builder)->allocated_children = 1;
3366 GVSB(builder)->expected_type =
3367 g_variant_type_element (GVSB(builder)->type);
3368 GVSB(builder)->min_items = 0;
3369 GVSB(builder)->max_items = 1;
3370 break;
3371
3372 case G_VARIANT_CLASS_DICT_ENTRY:
3373 GVSB(builder)->uniform_item_types = FALSE;
3374 GVSB(builder)->allocated_children = 2;
3375 GVSB(builder)->expected_type =
3376 g_variant_type_key (GVSB(builder)->type);
3377 GVSB(builder)->min_items = 2;
3378 GVSB(builder)->max_items = 2;
3379 break;
3380
3381 case 'r': /* G_VARIANT_TYPE_TUPLE was given */
3382 GVSB(builder)->uniform_item_types = FALSE;
3383 GVSB(builder)->allocated_children = 8;
3384 GVSB(builder)->expected_type = NULL;
3385 GVSB(builder)->min_items = 0;
3386 GVSB(builder)->max_items = -1;
3387 break;
3388
3389 case G_VARIANT_CLASS_TUPLE: /* a definite tuple type was given */
3390 GVSB(builder)->allocated_children = g_variant_type_n_items (type);
3391 GVSB(builder)->expected_type =
3392 g_variant_type_first (GVSB(builder)->type);
3393 GVSB(builder)->min_items = GVSB(builder)->allocated_children;
3394 GVSB(builder)->max_items = GVSB(builder)->allocated_children;
3395 GVSB(builder)->uniform_item_types = FALSE;
3396 break;
3397
3398 default:
3399 g_assert_not_reached ();
3400 }
3401
3402 GVSB(builder)->children = g_new (GVariant *,
3403 GVSB(builder)->allocated_children);
3404 }
3405
3406 static void
3407 g_variant_builder_make_room (struct stack_builder *builder)
3408 {
3409 if (builder->offset == builder->allocated_children)
3410 {
3411 builder->allocated_children *= 2;
3412 builder->children = g_renew (GVariant *, builder->children,
3413 builder->allocated_children);
3414 }
3415 }
3416
3417 /**
3418 * g_variant_builder_add_value:
3419 * @builder: a #GVariantBuilder
3420 * @value: a #GVariant
3421 *
3422 * Adds @value to @builder.
3423 *
3424 * It is an error to call this function in any way that would create an
3425 * inconsistent value to be constructed. Some examples of this are
3426 * putting different types of items into an array, putting the wrong
3427 * types or number of items in a tuple, putting more than one value into
3428 * a variant, etc.
3429 *
3430 * If @value is a floating reference (see g_variant_ref_sink()),
3431 * the @builder instance takes ownership of @value.
3432 *
3433 * Since: 2.24
3434 **/
3435 void
3436 g_variant_builder_add_value (GVariantBuilder *builder,
3437 GVariant *value)
3438 {
3439 g_return_if_fail (is_valid_builder (builder));
3440 g_return_if_fail (GVSB(builder)->offset < GVSB(builder)->max_items);
3441 g_return_if_fail (!GVSB(builder)->expected_type ||
3442 g_variant_is_of_type (value,
3443 GVSB(builder)->expected_type));
3444 g_return_if_fail (!GVSB(builder)->prev_item_type ||
3445 g_variant_is_of_type (value,
3446 GVSB(builder)->prev_item_type));
3447
3448 GVSB(builder)->trusted &= g_variant_is_trusted (value);
3449
3450 if (!GVSB(builder)->uniform_item_types)
3451 {
3452 /* advance our expected type pointers */
3453 if (GVSB(builder)->expected_type)
3454 GVSB(builder)->expected_type =
3455 g_variant_type_next (GVSB(builder)->expected_type);
3456
3457 if (GVSB(builder)->prev_item_type)
3458 GVSB(builder)->prev_item_type =
3459 g_variant_type_next (GVSB(builder)->prev_item_type);
3460 }
3461 else
3462 GVSB(builder)->prev_item_type = g_variant_get_type (value);
3463
3464 g_variant_builder_make_room (GVSB(builder));
3465
3466 GVSB(builder)->children[GVSB(builder)->offset++] =
3467 g_variant_ref_sink (value);
3468 }
3469
3470 /**
3471 * g_variant_builder_open:
3472 * @builder: a #GVariantBuilder
3473 * @type: a #GVariantType
3474 *
3475 * Opens a subcontainer inside the given @builder. When done adding
3476 * items to the subcontainer, g_variant_builder_close() must be called.
3477 *
3478 * It is an error to call this function in any way that would cause an
3479 * inconsistent value to be constructed (ie: adding too many values or
3480 * a value of an incorrect type).
3481 *
3482 * Since: 2.24
3483 **/
3484 void
3485 g_variant_builder_open (GVariantBuilder *builder,
3486 const GVariantType *type)
3487 {
3488 GVariantBuilder *parent;
3489
3490 g_return_if_fail (is_valid_builder (builder));
3491 g_return_if_fail (GVSB(builder)->offset < GVSB(builder)->max_items);
3492 g_return_if_fail (!GVSB(builder)->expected_type ||
3493 g_variant_type_is_subtype_of (type,
3494 GVSB(builder)->expected_type));
3495 g_return_if_fail (!GVSB(builder)->prev_item_type ||
3496 g_variant_type_is_subtype_of (GVSB(builder)->prev_item_type,
3497 type));
3498
3499 parent = g_slice_dup (GVariantBuilder, builder);
3500 g_variant_builder_init (builder, type);
3501 GVSB(builder)->parent = parent;
3502
3503 /* push the prev_item_type down into the subcontainer */
3504 if (GVSB(parent)->prev_item_type)
3505 {
3506 if (!GVSB(builder)->uniform_item_types)
3507 /* tuples and dict entries */
3508 GVSB(builder)->prev_item_type =
3509 g_variant_type_first (GVSB(parent)->prev_item_type);
3510
3511 else if (!g_variant_type_is_variant (GVSB(builder)->type))
3512 /* maybes and arrays */
3513 GVSB(builder)->prev_item_type =
3514 g_variant_type_element (GVSB(parent)->prev_item_type);
3515 }
3516 }
3517
3518 /**
3519 * g_variant_builder_close:
3520 * @builder: a #GVariantBuilder
3521 *
3522 * Closes the subcontainer inside the given @builder that was opened by
3523 * the most recent call to g_variant_builder_open().
3524 *
3525 * It is an error to call this function in any way that would create an
3526 * inconsistent value to be constructed (ie: too few values added to the
3527 * subcontainer).
3528 *
3529 * Since: 2.24
3530 **/
3531 void
3532 g_variant_builder_close (GVariantBuilder *builder)
3533 {
3534 GVariantBuilder *parent;
3535
3536 g_return_if_fail (is_valid_builder (builder));
3537 g_return_if_fail (GVSB(builder)->parent != NULL);
3538
3539 parent = GVSB(builder)->parent;
3540 GVSB(builder)->parent = NULL;
3541
3542 g_variant_builder_add_value (parent, g_variant_builder_end (builder));
3543 *builder = *parent;
3544
3545 g_slice_free (GVariantBuilder, parent);
3546 }
3547
3548 /*< private >
3549 * g_variant_make_maybe_type:
3550 * @element: a #GVariant
3551 *
3552 * Return the type of a maybe containing @element.
3553 */
3554 static GVariantType *
3555 g_variant_make_maybe_type (GVariant *element)
3556 {
3557 return g_variant_type_new_maybe (g_variant_get_type (element));
3558 }
3559
3560 /*< private >
3561 * g_variant_make_array_type:
3562 * @element: a #GVariant
3563 *
3564 * Return the type of an array containing @element.
3565 */
3566 static GVariantType *
3567 g_variant_make_array_type (GVariant *element)
3568 {
3569 return g_variant_type_new_array (g_variant_get_type (element));
3570 }
3571
3572 /**
3573 * g_variant_builder_end:
3574 * @builder: a #GVariantBuilder
3575 *
3576 * Ends the builder process and returns the constructed value.
3577 *
3578 * It is not permissible to use @builder in any way after this call
3579 * except for reference counting operations (in the case of a
3580 * heap-allocated #GVariantBuilder) or by reinitialising it with
3581 * g_variant_builder_init() (in the case of stack-allocated).
3582 *
3583 * It is an error to call this function in any way that would create an
3584 * inconsistent value to be constructed (ie: insufficient number of
3585 * items added to a container with a specific number of children
3586 * required). It is also an error to call this function if the builder
3587 * was created with an indefinite array or maybe type and no children
3588 * have been added; in this case it is impossible to infer the type of
3589 * the empty array.
3590 *
3591 * Returns: (transfer none): a new, floating, #GVariant
3592 *
3593 * Since: 2.24
3594 **/
3595 GVariant *
3596 g_variant_builder_end (GVariantBuilder *builder)
3597 {
3598 GVariantType *my_type;
3599 GVariant *value;
3600
3601 g_return_val_if_fail (is_valid_builder (builder), NULL);
3602 g_return_val_if_fail (GVSB(builder)->offset >= GVSB(builder)->min_items,
3603 NULL);
3604 g_return_val_if_fail (!GVSB(builder)->uniform_item_types ||
3605 GVSB(builder)->prev_item_type != NULL ||
3606 g_variant_type_is_definite (GVSB(builder)->type),
3607 NULL);
3608
3609 if (g_variant_type_is_definite (GVSB(builder)->type))
3610 my_type = g_variant_type_copy (GVSB(builder)->type);
3611
3612 else if (g_variant_type_is_maybe (GVSB(builder)->type))
3613 my_type = g_variant_make_maybe_type (GVSB(builder)->children[0]);
3614
3615 else if (g_variant_type_is_array (GVSB(builder)->type))
3616 my_type = g_variant_make_array_type (GVSB(builder)->children[0]);
3617
3618 else if (g_variant_type_is_tuple (GVSB(builder)->type))
3619 my_type = g_variant_make_tuple_type (GVSB(builder)->children,
3620 GVSB(builder)->offset);
3621
3622 else if (g_variant_type_is_dict_entry (GVSB(builder)->type))
3623 my_type = g_variant_make_dict_entry_type (GVSB(builder)->children[0],
3624 GVSB(builder)->children[1]);
3625 else
3626 g_assert_not_reached ();
3627
3628 value = g_variant_new_from_children (my_type,
3629 g_renew (GVariant *,
3630 GVSB(builder)->children,
3631 GVSB(builder)->offset),
3632 GVSB(builder)->offset,
3633 GVSB(builder)->trusted);
3634 GVSB(builder)->children = NULL;
3635 GVSB(builder)->offset = 0;
3636
3637 g_variant_builder_clear (builder);
3638 g_variant_type_free (my_type);
3639
3640 return value;
3641 }
3642
3643 /* GVariantDict {{{1 */
3644
3645 /**
3646 * GVariantDict:
3647 *
3648 * #GVariantDict is a mutable interface to #GVariant dictionaries.
3649 *
3650 * It can be used for doing a sequence of dictionary lookups in an
3651 * efficient way on an existing #GVariant dictionary or it can be used
3652 * to construct new dictionaries with a hashtable-like interface. It
3653 * can also be used for taking existing dictionaries and modifying them
3654 * in order to create new ones.
3655 *
3656 * #GVariantDict can only be used with %G_VARIANT_TYPE_VARDICT
3657 * dictionaries.
3658 *
3659 * It is possible to use #GVariantDict allocated on the stack or on the
3660 * heap. When using a stack-allocated #GVariantDict, you begin with a
3661 * call to g_variant_dict_init() and free the resources with a call to
3662 * g_variant_dict_clear().
3663 *
3664 * Heap-allocated #GVariantDict follows normal refcounting rules: you
3665 * allocate it with g_variant_dict_new() and use g_variant_dict_ref()
3666 * and g_variant_dict_unref().
3667 *
3668 * g_variant_dict_end() is used to convert the #GVariantDict back into a
3669 * dictionary-type #GVariant. When used with stack-allocated instances,
3670 * this also implicitly frees all associated memory, but for
3671 * heap-allocated instances, you must still call g_variant_dict_unref()
3672 * afterwards.
3673 *
3674 * You will typically want to use a heap-allocated #GVariantDict when
3675 * you expose it as part of an API. For most other uses, the
3676 * stack-allocated form will be more convenient.
3677 *
3678 * Consider the following two examples that do the same thing in each
3679 * style: take an existing dictionary and look up the "count" uint32
3680 * key, adding 1 to it if it is found, or returning an error if the
3681 * key is not found. Each returns the new dictionary as a floating
3682 * #GVariant.
3683 *
3684 * ## Using a stack-allocated GVariantDict
3685 *
3686 * |[<!-- language="C" -->
3687 * GVariant *
3688 * add_to_count (GVariant *orig,
3689 * GError **error)
3690 * {
3691 * GVariantDict dict;
3692 * guint32 count;
3693 *
3694 * g_variant_dict_init (&dict, orig);
3695 * if (!g_variant_dict_lookup (&dict, "count", "u", &count))
3696 * {
3697 * g_set_error (...);
3698 * g_variant_dict_clear (&dict);
3699 * return NULL;
3700 * }
3701 *
3702 * g_variant_dict_insert (&dict, "count", "u", count + 1);
3703 *
3704 * return g_variant_dict_end (&dict);
3705 * }
3706 * ]|
3707 *
3708 * ## Using heap-allocated GVariantDict
3709 *
3710 * |[<!-- language="C" -->
3711 * GVariant *
3712 * add_to_count (GVariant *orig,
3713 * GError **error)
3714 * {
3715 * GVariantDict *dict;
3716 * GVariant *result;
3717 * guint32 count;
3718 *
3719 * dict = g_variant_dict_new (orig);
3720 *
3721 * if (g_variant_dict_lookup (dict, "count", "u", &count))
3722 * {
3723 * g_variant_dict_insert (dict, "count", "u", count + 1);
3724 * result = g_variant_dict_end (dict);
3725 * }
3726 * else
3727 * {
3728 * g_set_error (...);
3729 * result = NULL;
3730 * }
3731 *
3732 * g_variant_dict_unref (dict);
3733 *
3734 * return result;
3735 * }
3736 * ]|
3737 *
3738 * Since: 2.40
3739 **/
3740 struct stack_dict
3741 {
3742 GHashTable *values;
3743 gsize magic;
3744 };
3745
3746 G_STATIC_ASSERT (sizeof (struct stack_dict) <= sizeof (GVariantDict));
3747
3748 struct heap_dict
3749 {
3750 struct stack_dict dict;
3751 gint ref_count;
3752 gsize magic;
3753 };
3754
3755 #define GVSD(d) ((struct stack_dict *) (d))
3756 #define GVHD(d) ((struct heap_dict *) (d))
3757 #define GVSD_MAGIC ((gsize) 2579507750u)
3758 #define GVHD_MAGIC ((gsize) 2450270775u)
3759 #define is_valid_dict(d) (d != NULL && \
3760 GVSD(d)->magic == GVSD_MAGIC)
3761 #define is_valid_heap_dict(d) (GVHD(d)->magic == GVHD_MAGIC)
3762
3763 /**
3764 * g_variant_dict_new:
3765 * @from_asv: (allow-none): the #GVariant with which to initialise the
3766 * dictionary
3767 *
3768 * Allocates and initialises a new #GVariantDict.
3769 *
3770 * You should call g_variant_dict_unref() on the return value when it
3771 * is no longer needed. The memory will not be automatically freed by
3772 * any other call.
3773 *
3774 * In some cases it may be easier to place a #GVariantDict directly on
3775 * the stack of the calling function and initialise it with
3776 * g_variant_dict_init(). This is particularly useful when you are
3777 * using #GVariantDict to construct a #GVariant.
3778 *
3779 * Returns: (transfer full): a #GVariantDict
3780 *
3781 * Since: 2.40
3782 **/
3783 GVariantDict *
3784 g_variant_dict_new (GVariant *from_asv)
3785 {
3786 GVariantDict *dict;
3787
3788 dict = g_slice_alloc (sizeof (struct heap_dict));
3789 g_variant_dict_init (dict, from_asv);
3790 GVHD(dict)->magic = GVHD_MAGIC;
3791 GVHD(dict)->ref_count = 1;
3792
3793 return dict;
3794 }
3795
3796 /**
3797 * g_variant_dict_init: (skip)
3798 * @dict: a #GVariantDict
3799 * @from_asv: (allow-none): the initial value for @dict
3800 *
3801 * Initialises a #GVariantDict structure.
3802 *
3803 * If @from_asv is given, it is used to initialise the dictionary.
3804 *
3805 * This function completely ignores the previous contents of @dict. On
3806 * one hand this means that it is valid to pass in completely
3807 * uninitialised memory. On the other hand, this means that if you are
3808 * initialising over top of an existing #GVariantDict you need to first
3809 * call g_variant_dict_clear() in order to avoid leaking memory.
3810 *
3811 * You must not call g_variant_dict_ref() or g_variant_dict_unref() on a
3812 * #GVariantDict that was initialised with this function. If you ever
3813 * pass a reference to a #GVariantDict outside of the control of your
3814 * own code then you should assume that the person receiving that
3815 * reference may try to use reference counting; you should use
3816 * g_variant_dict_new() instead of this function.
3817 *
3818 * Since: 2.40
3819 **/
3820 void
3821 g_variant_dict_init (GVariantDict *dict,
3822 GVariant *from_asv)
3823 {
3824 GVariantIter iter;
3825 gchar *key;
3826 GVariant *value;
3827
3828 GVSD(dict)->values = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify) g_variant_unref);
3829 GVSD(dict)->magic = GVSD_MAGIC;
3830
3831 if (from_asv)
3832 {
3833 g_variant_iter_init (&iter, from_asv);
3834 while (g_variant_iter_next (&iter, "{sv}", &key, &value))
3835 g_hash_table_insert (GVSD(dict)->values, key, value);
3836 }
3837 }
3838
3839 /**
3840 * g_variant_dict_lookup:
3841 * @dict: a #GVariantDict
3842 * @key: the key to lookup in the dictionary
3843 * @format_string: a GVariant format string
3844 * @...: the arguments to unpack the value into
3845 *
3846 * Looks up a value in a #GVariantDict.
3847 *
3848 * This function is a wrapper around g_variant_dict_lookup_value() and
3849 * g_variant_get(). In the case that %NULL would have been returned,
3850 * this function returns %FALSE. Otherwise, it unpacks the returned
3851 * value and returns %TRUE.
3852 *
3853 * @format_string determines the C types that are used for unpacking the
3854 * values and also determines if the values are copied or borrowed, see the
3855 * section on [GVariant format strings][gvariant-format-strings-pointers].
3856 *
3857 * Returns: %TRUE if a value was unpacked
3858 *
3859 * Since: 2.40
3860 **/
3861 gboolean
3862 g_variant_dict_lookup (GVariantDict *dict,
3863 const gchar *key,
3864 const gchar *format_string,
3865 ...)
3866 {
3867 GVariant *value;
3868 va_list ap;
3869
3870 g_return_val_if_fail (is_valid_dict (dict), FALSE);
3871 g_return_val_if_fail (key != NULL, FALSE);
3872 g_return_val_if_fail (format_string != NULL, FALSE);
3873
3874 value = g_hash_table_lookup (GVSD(dict)->values, key);
3875
3876 if (value == NULL || !g_variant_check_format_string (value, format_string, FALSE))
3877 return FALSE;
3878
3879 va_start (ap, format_string);
3880 g_variant_get_va (value, format_string, NULL, &ap);
3881 va_end (ap);
3882
3883 return TRUE;
3884 }
3885
3886 /**
3887 * g_variant_dict_lookup_value:
3888 * @dict: a #GVariantDict
3889 * @key: the key to lookup in the dictionary
3890 * @expected_type: (allow-none): a #GVariantType, or %NULL
3891 *
3892 * Looks up a value in a #GVariantDict.
3893 *
3894 * If @key is not found in @dictionary, %NULL is returned.
3895 *
3896 * The @expected_type string specifies what type of value is expected.
3897 * If the value associated with @key has a different type then %NULL is
3898 * returned.
3899 *
3900 * If the key is found and the value has the correct type, it is
3901 * returned. If @expected_type was specified then any non-%NULL return
3902 * value will have this type.
3903 *
3904 * Returns: (transfer full): the value of the dictionary key, or %NULL
3905 *
3906 * Since: 2.40
3907 **/
3908 GVariant *
3909 g_variant_dict_lookup_value (GVariantDict *dict,
3910 const gchar *key,
3911 const GVariantType *expected_type)
3912 {
3913 GVariant *result;
3914
3915 g_return_val_if_fail (is_valid_dict (dict), NULL);
3916 g_return_val_if_fail (key != NULL, NULL);
3917
3918 result = g_hash_table_lookup (GVSD(dict)->values, key);
3919
3920 if (result && (!expected_type || g_variant_is_of_type (result, expected_type)))
3921 return g_variant_ref (result);
3922
3923 return NULL;
3924 }
3925
3926 /**
3927 * g_variant_dict_contains:
3928 * @dict: a #GVariantDict
3929 * @key: the key to lookup in the dictionary
3930 *
3931 * Checks if @key exists in @dict.
3932 *
3933 * Returns: %TRUE if @key is in @dict
3934 *
3935 * Since: 2.40
3936 **/
3937 gboolean
3938 g_variant_dict_contains (GVariantDict *dict,
3939 const gchar *key)
3940 {
3941 g_return_val_if_fail (is_valid_dict (dict), FALSE);
3942 g_return_val_if_fail (key != NULL, FALSE);
3943
3944 return g_hash_table_contains (GVSD(dict)->values, key);
3945 }
3946
3947 /**
3948 * g_variant_dict_insert:
3949 * @dict: a #GVariantDict
3950 * @key: the key to insert a value for
3951 * @format_string: a #GVariant varargs format string
3952 * @...: arguments, as per @format_string
3953 *
3954 * Inserts a value into a #GVariantDict.
3955 *
3956 * This call is a convenience wrapper that is exactly equivalent to
3957 * calling g_variant_new() followed by g_variant_dict_insert_value().
3958 *
3959 * Since: 2.40
3960 **/
3961 void
3962 g_variant_dict_insert (GVariantDict *dict,
3963 const gchar *key,
3964 const gchar *format_string,
3965 ...)
3966 {
3967 va_list ap;
3968
3969 g_return_if_fail (is_valid_dict (dict));
3970 g_return_if_fail (key != NULL);
3971 g_return_if_fail (format_string != NULL);
3972
3973 va_start (ap, format_string);
3974 g_variant_dict_insert_value (dict, key, g_variant_new_va (format_string, NULL, &ap));
3975 va_end (ap);
3976 }
3977
3978 /**
3979 * g_variant_dict_insert_value:
3980 * @dict: a #GVariantDict
3981 * @key: the key to insert a value for
3982 * @value: the value to insert
3983 *
3984 * Inserts (or replaces) a key in a #GVariantDict.
3985 *
3986 * @value is consumed if it is floating.
3987 *
3988 * Since: 2.40
3989 **/
3990 void
3991 g_variant_dict_insert_value (GVariantDict *dict,
3992 const gchar *key,
3993 GVariant *value)
3994 {
3995 g_return_if_fail (is_valid_dict (dict));
3996 g_return_if_fail (key != NULL);
3997 g_return_if_fail (value != NULL);
3998
3999 g_hash_table_insert (GVSD(dict)->values, g_strdup (key), g_variant_ref_sink (value));
4000 }
4001
4002 /**
4003 * g_variant_dict_remove:
4004 * @dict: a #GVariantDict
4005 * @key: the key to remove
4006 *
4007 * Removes a key and its associated value from a #GVariantDict.
4008 *
4009 * Returns: %TRUE if the key was found and removed
4010 *
4011 * Since: 2.40
4012 **/
4013 gboolean
4014 g_variant_dict_remove (GVariantDict *dict,
4015 const gchar *key)
4016 {
4017 g_return_val_if_fail (is_valid_dict (dict), FALSE);
4018 g_return_val_if_fail (key != NULL, FALSE);
4019
4020 return g_hash_table_remove (GVSD(dict)->values, key);
4021 }
4022
4023 /**
4024 * g_variant_dict_clear:
4025 * @dict: a #GVariantDict
4026 *
4027 * Releases all memory associated with a #GVariantDict without freeing
4028 * the #GVariantDict structure itself.
4029 *
4030 * It typically only makes sense to do this on a stack-allocated
4031 * #GVariantDict if you want to abort building the value part-way
4032 * through. This function need not be called if you call
4033 * g_variant_dict_end() and it also doesn't need to be called on dicts
4034 * allocated with g_variant_dict_new (see g_variant_dict_unref() for
4035 * that).
4036 *
4037 * It is valid to call this function on either an initialised
4038 * #GVariantDict or one that was previously cleared by an earlier call
4039 * to g_variant_dict_clear() but it is not valid to call this function
4040 * on uninitialised memory.
4041 *
4042 * Since: 2.40
4043 **/
4044 void
4045 g_variant_dict_clear (GVariantDict *dict)
4046 {
4047 if (GVSD(dict)->magic == 0)
4048 /* all-zeros case */
4049 return;
4050
4051 g_return_if_fail (is_valid_dict (dict));
4052
4053 g_hash_table_unref (GVSD(dict)->values);
4054 GVSD(dict)->values = NULL;
4055
4056 GVSD(dict)->magic = 0;
4057 }
4058
4059 /**
4060 * g_variant_dict_end:
4061 * @dict: a #GVariantDict
4062 *
4063 * Returns the current value of @dict as a #GVariant of type
4064 * %G_VARIANT_TYPE_VARDICT, clearing it in the process.
4065 *
4066 * It is not permissible to use @dict in any way after this call except
4067 * for reference counting operations (in the case of a heap-allocated
4068 * #GVariantDict) or by reinitialising it with g_variant_dict_init() (in
4069 * the case of stack-allocated).
4070 *
4071 * Returns: (transfer none): a new, floating, #GVariant
4072 *
4073 * Since: 2.40
4074 **/
4075 GVariant *
4076 g_variant_dict_end (GVariantDict *dict)
4077 {
4078 GVariantBuilder builder;
4079 GHashTableIter iter;
4080 gpointer key, value;
4081
4082 g_return_val_if_fail (is_valid_dict (dict), NULL);
4083
4084 g_variant_builder_init (&builder, G_VARIANT_TYPE_VARDICT);
4085
4086 g_hash_table_iter_init (&iter, GVSD(dict)->values);
4087 while (g_hash_table_iter_next (&iter, &key, &value))
4088 g_variant_builder_add (&builder, "{sv}", (const gchar *) key, (GVariant *) value);
4089
4090 g_variant_dict_clear (dict);
4091
4092 return g_variant_builder_end (&builder);
4093 }
4094
4095 /**
4096 * g_variant_dict_ref:
4097 * @dict: a heap-allocated #GVariantDict
4098 *
4099 * Increases the reference count on @dict.
4100 *
4101 * Don't call this on stack-allocated #GVariantDict instances or bad
4102 * things will happen.
4103 *
4104 * Returns: (transfer full): a new reference to @dict
4105 *
4106 * Since: 2.40
4107 **/
4108 GVariantDict *
4109 g_variant_dict_ref (GVariantDict *dict)
4110 {
4111 g_return_val_if_fail (is_valid_heap_dict (dict), NULL);
4112
4113 GVHD(dict)->ref_count++;
4114
4115 return dict;
4116 }
4117
4118 /**
4119 * g_variant_dict_unref:
4120 * @dict: (transfer full): a heap-allocated #GVariantDict
4121 *
4122 * Decreases the reference count on @dict.
4123 *
4124 * In the event that there are no more references, releases all memory
4125 * associated with the #GVariantDict.
4126 *
4127 * Don't call this on stack-allocated #GVariantDict instances or bad
4128 * things will happen.
4129 *
4130 * Since: 2.40
4131 **/
4132 void
4133 g_variant_dict_unref (GVariantDict *dict)
4134 {
4135 g_return_if_fail (is_valid_heap_dict (dict));
4136
4137 if (--GVHD(dict)->ref_count == 0)
4138 {
4139 g_variant_dict_clear (dict);
4140 g_slice_free (struct heap_dict, (struct heap_dict *) dict);
4141 }
4142 }
4143
4144
4145 /* Format strings {{{1 */
4146 /*< private >
4147 * g_variant_format_string_scan:
4148 * @string: a string that may be prefixed with a format string
4149 * @limit: (allow-none) (default NULL): a pointer to the end of @string,
4150 * or %NULL
4151 * @endptr: (allow-none) (default NULL): location to store the end pointer,
4152 * or %NULL
4153 *
4154 * Checks the string pointed to by @string for starting with a properly
4155 * formed #GVariant varargs format string. If no valid format string is
4156 * found then %FALSE is returned.
4157 *
4158 * If @string does start with a valid format string then %TRUE is
4159 * returned. If @endptr is non-%NULL then it is updated to point to the
4160 * first character after the format string.
4161 *
4162 * If @limit is non-%NULL then @limit (and any charater after it) will
4163 * not be accessed and the effect is otherwise equivalent to if the
4164 * character at @limit were nul.
4165 *
4166 * See the section on [GVariant format strings][gvariant-format-strings].
4167 *
4168 * Returns: %TRUE if there was a valid format string
4169 *
4170 * Since: 2.24
4171 */
4172 gboolean
4173 g_variant_format_string_scan (const gchar *string,
4174 const gchar *limit,
4175 const gchar **endptr)
4176 {
4177 #define next_char() (string == limit ? '\0' : *string++)
4178 #define peek_char() (string == limit ? '\0' : *string)
4179 char c;
4180
4181 switch (next_char())
4182 {
4183 case 'b': case 'y': case 'n': case 'q': case 'i': case 'u':
4184 case 'x': case 't': case 'h': case 'd': case 's': case 'o':
4185 case 'g': case 'v': case '*': case '?': case 'r':
4186 break;
4187
4188 case 'm':
4189 return g_variant_format_string_scan (string, limit, endptr);
4190
4191 case 'a':
4192 case '@':
4193 return g_variant_type_string_scan (string, limit, endptr);
4194
4195 case '(':
4196 while (peek_char() != ')')
4197 if (!g_variant_format_string_scan (string, limit, &string))
4198 return FALSE;
4199
4200 next_char(); /* consume ')' */
4201 break;
4202
4203 case '{':
4204 c = next_char();
4205
4206 if (c == '&')
4207 {
4208 c = next_char ();
4209
4210 if (c != 's' && c != 'o' && c != 'g')
4211 return FALSE;
4212 }
4213 else
4214 {
4215 if (c == '@')
4216 c = next_char ();
4217
4218 /* ISO/IEC 9899:1999 (C99) §7.21.5.2:
4219 * The terminating null character is considered to be
4220 * part of the string.
4221 */
4222 if (c != '\0' && strchr ("bynqiuxthdsog?", c) == NULL)
4223 return FALSE;
4224 }
4225
4226 if (!g_variant_format_string_scan (string, limit, &string))
4227 return FALSE;
4228
4229 if (next_char() != '}')
4230 return FALSE;
4231
4232 break;
4233
4234 case '^':
4235 if ((c = next_char()) == 'a')
4236 {
4237 if ((c = next_char()) == '&')
4238 {
4239 if ((c = next_char()) == 'a')
4240 {
4241 if ((c = next_char()) == 'y')
4242 break; /* '^a&ay' */
4243 }
4244
4245 else if (c == 's' || c == 'o')
4246 break; /* '^a&s', '^a&o' */
4247 }
4248
4249 else if (c == 'a')
4250 {
4251 if ((c = next_char()) == 'y')
4252 break; /* '^aay' */
4253 }
4254
4255 else if (c == 's' || c == 'o')
4256 break; /* '^as', '^ao' */
4257
4258 else if (c == 'y')
4259 break; /* '^ay' */
4260 }
4261 else if (c == '&')
4262 {
4263 if ((c = next_char()) == 'a')
4264 {
4265 if ((c = next_char()) == 'y')
4266 break; /* '^&ay' */
4267 }
4268 }
4269
4270 return FALSE;
4271
4272 case '&':
4273 c = next_char();
4274
4275 if (c != 's' && c != 'o' && c != 'g')
4276 return FALSE;
4277
4278 break;
4279
4280 default:
4281 return FALSE;
4282 }
4283
4284 if (endptr != NULL)
4285 *endptr = string;
4286
4287 #undef next_char
4288 #undef peek_char
4289
4290 return TRUE;
4291 }
4292
4293 /**
4294 * g_variant_check_format_string:
4295 * @value: a #GVariant
4296 * @format_string: a valid #GVariant format string
4297 * @copy_only: %TRUE to ensure the format string makes deep copies
4298 *
4299 * Checks if calling g_variant_get() with @format_string on @value would
4300 * be valid from a type-compatibility standpoint. @format_string is
4301 * assumed to be a valid format string (from a syntactic standpoint).
4302 *
4303 * If @copy_only is %TRUE then this function additionally checks that it
4304 * would be safe to call g_variant_unref() on @value immediately after
4305 * the call to g_variant_get() without invalidating the result. This is
4306 * only possible if deep copies are made (ie: there are no pointers to
4307 * the data inside of the soon-to-be-freed #GVariant instance). If this
4308 * check fails then a g_critical() is printed and %FALSE is returned.
4309 *
4310 * This function is meant to be used by functions that wish to provide
4311 * varargs accessors to #GVariant values of uncertain values (eg:
4312 * g_variant_lookup() or g_menu_model_get_item_attribute()).
4313 *
4314 * Returns: %TRUE if @format_string is safe to use
4315 *
4316 * Since: 2.34
4317 */
4318 gboolean
4319 g_variant_check_format_string (GVariant *value,
4320 const gchar *format_string,
4321 gboolean copy_only)
4322 {
4323 const gchar *original_format = format_string;
4324 const gchar *type_string;
4325
4326 /* Interesting factoid: assuming a format string is valid, it can be
4327 * converted to a type string by removing all '@' '&' and '^'
4328 * characters.
4329 *
4330 * Instead of doing that, we can just skip those characters when
4331 * comparing it to the type string of @value.
4332 *
4333 * For the copy-only case we can just drop the '&' from the list of
4334 * characters to skip over. A '&' will never appear in a type string
4335 * so we know that it won't be possible to return %TRUE if it is in a
4336 * format string.
4337 */
4338 type_string = g_variant_get_type_string (value);
4339
4340 while (*type_string || *format_string)
4341 {
4342 gchar format = *format_string++;
4343
4344 switch (format)
4345 {
4346 case '&':
4347 if G_UNLIKELY (copy_only)
4348 {
4349 /* for the love of all that is good, please don't mark this string for translation... */
4350 g_critical ("g_variant_check_format_string() is being called by a function with a GVariant varargs "
4351 "interface to validate the passed format string for type safety. The passed format "
4352 "(%s) contains a '&' character which would result in a pointer being returned to the "
4353 "data inside of a GVariant instance that may no longer exist by the time the function "
4354 "returns. Modify your code to use a format string without '&'.", original_format);
4355 return FALSE;
4356 }
4357
4358 /* fall through */
4359 case '^':
4360 case '@':
4361 /* ignore these 2 (or 3) */
4362 continue;
4363
4364 case '?':
4365 /* attempt to consume one of 'bynqiuxthdsog' */
4366 {
4367 char s = *type_string++;
4368
4369 if (s == '\0' || strchr ("bynqiuxthdsog", s) == NULL)
4370 return FALSE;
4371 }
4372 continue;
4373
4374 case 'r':
4375 /* ensure it's a tuple */
4376 if (*type_string != '(')
4377 return FALSE;
4378
4379 /* fall through */
4380 case '*':
4381 /* consume a full type string for the '*' or 'r' */
4382 if (!g_variant_type_string_scan (type_string, NULL, &type_string))
4383 return FALSE;
4384
4385 continue;
4386
4387 default:
4388 /* attempt to consume exactly one character equal to the format */
4389 if (format != *type_string++)
4390 return FALSE;
4391 }
4392 }
4393
4394 return TRUE;
4395 }
4396
4397 /*< private >
4398 * g_variant_format_string_scan_type:
4399 * @string: a string that may be prefixed with a format string
4400 * @limit: (allow-none) (default NULL): a pointer to the end of @string,
4401 * or %NULL
4402 * @endptr: (allow-none) (default NULL): location to store the end pointer,
4403 * or %NULL
4404 *
4405 * If @string starts with a valid format string then this function will
4406 * return the type that the format string corresponds to. Otherwise
4407 * this function returns %NULL.
4408 *
4409 * Use g_variant_type_free() to free the return value when you no longer
4410 * need it.
4411 *
4412 * This function is otherwise exactly like
4413 * g_variant_format_string_scan().
4414 *
4415 * Returns: (allow-none): a #GVariantType if there was a valid format string
4416 *
4417 * Since: 2.24
4418 */
4419 GVariantType *
4420 g_variant_format_string_scan_type (const gchar *string,
4421 const gchar *limit,
4422 const gchar **endptr)
4423 {
4424 const gchar *my_end;
4425 gchar *dest;
4426 gchar *new;
4427
4428 if (endptr == NULL)
4429 endptr = &my_end;
4430
4431 if (!g_variant_format_string_scan (string, limit, endptr))
4432 return NULL;
4433
4434 dest = new = g_malloc (*endptr - string + 1);
4435 while (string != *endptr)
4436 {
4437 if (*string != '@' && *string != '&' && *string != '^')
4438 *dest++ = *string;
4439 string++;
4440 }
4441 *dest = '\0';
4442
4443 return (GVariantType *) G_VARIANT_TYPE (new);
4444 }
4445
4446 static gboolean
4447 valid_format_string (const gchar *format_string,
4448 gboolean single,
4449 GVariant *value)
4450 {
4451 const gchar *endptr;
4452 GVariantType *type;
4453
4454 type = g_variant_format_string_scan_type (format_string, NULL, &endptr);
4455
4456 if G_UNLIKELY (type == NULL || (single && *endptr != '\0'))
4457 {
4458 if (single)
4459 g_critical ("'%s' is not a valid GVariant format string",
4460 format_string);
4461 else
4462 g_critical ("'%s' does not have a valid GVariant format "
4463 "string as a prefix", format_string);
4464
4465 if (type != NULL)
4466 g_variant_type_free (type);
4467
4468 return FALSE;
4469 }
4470
4471 if G_UNLIKELY (value && !g_variant_is_of_type (value, type))
4472 {
4473 gchar *fragment;
4474 gchar *typestr;
4475
4476 fragment = g_strndup (format_string, endptr - format_string);
4477 typestr = g_variant_type_dup_string (type);
4478
4479 g_critical ("the GVariant format string '%s' has a type of "
4480 "'%s' but the given value has a type of '%s'",
4481 fragment, typestr, g_variant_get_type_string (value));
4482
4483 g_variant_type_free (type);
4484 g_free (fragment);
4485 g_free (typestr);
4486
4487 return FALSE;
4488 }
4489
4490 g_variant_type_free (type);
4491
4492 return TRUE;
4493 }
4494
4495 /* Variable Arguments {{{1 */
4496 /* We consider 2 main classes of format strings:
4497 *
4498 * - recursive format strings
4499 * these are ones that result in recursion and the collection of
4500 * possibly more than one argument. Maybe types, tuples,
4501 * dictionary entries.
4502 *
4503 * - leaf format string
4504 * these result in the collection of a single argument.
4505 *
4506 * Leaf format strings are further subdivided into two categories:
4507 *
4508 * - single non-null pointer ("nnp")
4509 * these either collect or return a single non-null pointer.
4510 *
4511 * - other
4512 * these collect or return something else (bool, number, etc).
4513 *
4514 * Based on the above, the varargs handling code is split into 4 main parts:
4515 *
4516 * - nnp handling code
4517 * - leaf handling code (which may invoke nnp code)
4518 * - generic handling code (may be recursive, may invoke leaf code)
4519 * - user-facing API (which invokes the generic code)
4520 *
4521 * Each section implements some of the following functions:
4522 *
4523 * - skip:
4524 * collect the arguments for the format string as if
4525 * g_variant_new() had been called, but do nothing with them. used
4526 * for skipping over arguments when constructing a Nothing maybe
4527 * type.
4528 *
4529 * - new:
4530 * create a GVariant *
4531 *
4532 * - get:
4533 * unpack a GVariant *
4534 *
4535 * - free (nnp only):
4536 * free a previously allocated item
4537 */
4538
4539 static gboolean
4540 g_variant_format_string_is_leaf (const gchar *str)
4541 {
4542 return str[0] != 'm' && str[0] != '(' && str[0] != '{';
4543 }
4544
4545 static gboolean
4546 g_variant_format_string_is_nnp (const gchar *str)
4547 {
4548 return str[0] == 'a' || str[0] == 's' || str[0] == 'o' || str[0] == 'g' ||
4549 str[0] == '^' || str[0] == '@' || str[0] == '*' || str[0] == '?' ||
4550 str[0] == 'r' || str[0] == 'v' || str[0] == '&';
4551 }
4552
4553 /* Single non-null pointer ("nnp") {{{2 */
4554 static void
4555 g_variant_valist_free_nnp (const gchar *str,
4556 gpointer ptr)
4557 {
4558 switch (*str)
4559 {
4560 case 'a':
4561 g_variant_iter_free (ptr);
4562 break;
4563
4564 case '^':
4565 if (str[2] != '&') /* '^as', '^ao' */
4566 g_strfreev (ptr);
4567 else /* '^a&s', '^a&o' */
4568 g_free (ptr);
4569 break;
4570
4571 case 's':
4572 case 'o':
4573 case 'g':
4574 g_free (ptr);
4575 break;
4576
4577 case '@':
4578 case '*':
4579 case '?':
4580 case 'v':
4581 g_variant_unref (ptr);
4582 break;
4583
4584 case '&':
4585 break;
4586
4587 default:
4588 g_assert_not_reached ();
4589 }
4590 }
4591
4592 static gchar
4593 g_variant_scan_convenience (const gchar **str,
4594 gboolean *constant,
4595 guint *arrays)
4596 {
4597 *constant = FALSE;
4598 *arrays = 0;
4599
4600 for (;;)
4601 {
4602 char c = *(*str)++;
4603
4604 if (c == '&')
4605 *constant = TRUE;
4606
4607 else if (c == 'a')
4608 (*arrays)++;
4609
4610 else
4611 return c;
4612 }
4613 }
4614
4615 static GVariant *
4616 g_variant_valist_new_nnp (const gchar **str,
4617 gpointer ptr)
4618 {
4619 if (**str == '&')
4620 (*str)++;
4621
4622 switch (*(*str)++)
4623 {
4624 case 'a':
4625 if (ptr != NULL)
4626 {
4627 const GVariantType *type;
4628 GVariant *value;
4629
4630 value = g_variant_builder_end (ptr);
4631 type = g_variant_get_type (value);
4632
4633 if G_UNLIKELY (!g_variant_type_is_array (type))
4634 g_error ("g_variant_new: expected array GVariantBuilder but "
4635 "the built value has type '%s'",
4636 g_variant_get_type_string (value));
4637
4638 type = g_variant_type_element (type);
4639
4640 if G_UNLIKELY (!g_variant_type_is_subtype_of (type, (GVariantType *) *str))
4641 g_error ("g_variant_new: expected GVariantBuilder array element "
4642 "type '%s' but the built value has element type '%s'",
4643 g_variant_type_dup_string ((GVariantType *) *str),
4644 g_variant_get_type_string (value) + 1);
4645
4646 g_variant_type_string_scan (*str, NULL, str);
4647
4648 return value;
4649 }
4650 else
4651
4652 /* special case: NULL pointer for empty array */
4653 {
4654 const GVariantType *type = (GVariantType *) *str;
4655
4656 g_variant_type_string_scan (*str, NULL, str);
4657
4658 if G_UNLIKELY (!g_variant_type_is_definite (type))
4659 g_error ("g_variant_new: NULL pointer given with indefinite "
4660 "array type; unable to determine which type of empty "
4661 "array to construct.");
4662
4663 return g_variant_new_array (type, NULL, 0);
4664 }
4665
4666 case 's':
4667 {
4668 GVariant *value;
4669
4670 value = g_variant_new_string (ptr);
4671
4672 if (value == NULL)
4673 value = g_variant_new_string ("[Invalid UTF-8]");
4674
4675 return value;
4676 }
4677
4678 case 'o':
4679 return g_variant_new_object_path (ptr);
4680
4681 case 'g':
4682 return g_variant_new_signature (ptr);
4683
4684 case '^':
4685 {
4686 gboolean constant;
4687 guint arrays;
4688 gchar type;
4689
4690 type = g_variant_scan_convenience (str, &constant, &arrays);
4691
4692 if (type == 's')
4693 return g_variant_new_strv (ptr, -1);
4694
4695 if (type == 'o')
4696 return g_variant_new_objv (ptr, -1);
4697
4698 if (arrays > 1)
4699 return g_variant_new_bytestring_array (ptr, -1);
4700
4701 return g_variant_new_bytestring (ptr);
4702 }
4703
4704 case '@':
4705 if G_UNLIKELY (!g_variant_is_of_type (ptr, (GVariantType *) *str))
4706 g_error ("g_variant_new: expected GVariant of type '%s' but "
4707 "received value has type '%s'",
4708 g_variant_type_dup_string ((GVariantType *) *str),
4709 g_variant_get_type_string (ptr));
4710
4711 g_variant_type_string_scan (*str, NULL, str);
4712
4713 return ptr;
4714
4715 case '*':
4716 return ptr;
4717
4718 case '?':
4719 if G_UNLIKELY (!g_variant_type_is_basic (g_variant_get_type (ptr)))
4720 g_error ("g_variant_new: format string '?' expects basic-typed "
4721 "GVariant, but received value has type '%s'",
4722 g_variant_get_type_string (ptr));
4723
4724 return ptr;
4725
4726 case 'r':
4727 if G_UNLIKELY (!g_variant_type_is_tuple (g_variant_get_type (ptr)))
4728 g_error ("g_variant_new: format string 'r' expects tuple-typed "
4729 "GVariant, but received value has type '%s'",
4730 g_variant_get_type_string (ptr));
4731
4732 return ptr;
4733
4734 case 'v':
4735 return g_variant_new_variant (ptr);
4736
4737 default:
4738 g_assert_not_reached ();
4739 }
4740 }
4741
4742 static gpointer
4743 g_variant_valist_get_nnp (const gchar **str,
4744 GVariant *value)
4745 {
4746 switch (*(*str)++)
4747 {
4748 case 'a':
4749 g_variant_type_string_scan (*str, NULL, str);
4750 return g_variant_iter_new (value);
4751
4752 case '&':
4753 (*str)++;
4754 return (gchar *) g_variant_get_string (value, NULL);
4755
4756 case 's':
4757 case 'o':
4758 case 'g':
4759 return g_variant_dup_string (value, NULL);
4760
4761 case '^':
4762 {
4763 gboolean constant;
4764 guint arrays;
4765 gchar type;
4766
4767 type = g_variant_scan_convenience (str, &constant, &arrays);
4768
4769 if (type == 's')
4770 {
4771 if (constant)
4772 return g_variant_get_strv (value, NULL);
4773 else
4774 return g_variant_dup_strv (value, NULL);
4775 }
4776
4777 else if (type == 'o')
4778 {
4779 if (constant)
4780 return g_variant_get_objv (value, NULL);
4781 else
4782 return g_variant_dup_objv (value, NULL);
4783 }
4784
4785 else if (arrays > 1)
4786 {
4787 if (constant)
4788 return g_variant_get_bytestring_array (value, NULL);
4789 else
4790 return g_variant_dup_bytestring_array (value, NULL);
4791 }
4792
4793 else
4794 {
4795 if (constant)
4796 return (gchar *) g_variant_get_bytestring (value);
4797 else
4798 return g_variant_dup_bytestring (value, NULL);
4799 }
4800 }
4801
4802 case '@':
4803 g_variant_type_string_scan (*str, NULL, str);
4804 /* fall through */
4805
4806 case '*':
4807 case '?':
4808 case 'r':
4809 return g_variant_ref (value);
4810
4811 case 'v':
4812 return g_variant_get_variant (value);
4813
4814 default:
4815 g_assert_not_reached ();
4816 }
4817 }
4818
4819 /* Leaves {{{2 */
4820 static void
4821 g_variant_valist_skip_leaf (const gchar **str,
4822 va_list *app)
4823 {
4824 if (g_variant_format_string_is_nnp (*str))
4825 {
4826 g_variant_format_string_scan (*str, NULL, str);
4827 va_arg (*app, gpointer);
4828 return;
4829 }
4830
4831 switch (*(*str)++)
4832 {
4833 case 'b':
4834 case 'y':
4835 case 'n':
4836 case 'q':
4837 case 'i':
4838 case 'u':
4839 case 'h':
4840 va_arg (*app, int);
4841 return;
4842
4843 case 'x':
4844 case 't':
4845 va_arg (*app, guint64);
4846 return;
4847
4848 case 'd':
4849 va_arg (*app, gdouble);
4850 return;
4851
4852 default:
4853 g_assert_not_reached ();
4854 }
4855 }
4856
4857 static GVariant *
4858 g_variant_valist_new_leaf (const gchar **str,
4859 va_list *app)
4860 {
4861 if (g_variant_format_string_is_nnp (*str))
4862 return g_variant_valist_new_nnp (str, va_arg (*app, gpointer));
4863
4864 switch (*(*str)++)
4865 {
4866 case 'b':
4867 return g_variant_new_boolean (va_arg (*app, gboolean));
4868
4869 case 'y':
4870 return g_variant_new_byte (va_arg (*app, guint));
4871
4872 case 'n':
4873 return g_variant_new_int16 (va_arg (*app, gint));
4874
4875 case 'q':
4876 return g_variant_new_uint16 (va_arg (*app, guint));
4877
4878 case 'i':
4879 return g_variant_new_int32 (va_arg (*app, gint));
4880
4881 case 'u':
4882 return g_variant_new_uint32 (va_arg (*app, guint));
4883
4884 case 'x':
4885 return g_variant_new_int64 (va_arg (*app, gint64));
4886
4887 case 't':
4888 return g_variant_new_uint64 (va_arg (*app, guint64));
4889
4890 case 'h':
4891 return g_variant_new_handle (va_arg (*app, gint));
4892
4893 case 'd':
4894 return g_variant_new_double (va_arg (*app, gdouble));
4895
4896 default:
4897 g_assert_not_reached ();
4898 }
4899 }
4900
4901 /* The code below assumes this */
4902 G_STATIC_ASSERT (sizeof (gboolean) == sizeof (guint32));
4903 G_STATIC_ASSERT (sizeof (gdouble) == sizeof (guint64));
4904
4905 static void
4906 g_variant_valist_get_leaf (const gchar **str,
4907 GVariant *value,
4908 gboolean free,
4909 va_list *app)
4910 {
4911 gpointer ptr = va_arg (*app, gpointer);
4912
4913 if (ptr == NULL)
4914 {
4915 g_variant_format_string_scan (*str, NULL, str);
4916 return;
4917 }
4918
4919 if (g_variant_format_string_is_nnp (*str))
4920 {
4921 gpointer *nnp = (gpointer *) ptr;
4922
4923 if (free && *nnp != NULL)
4924 g_variant_valist_free_nnp (*str, *nnp);
4925
4926 *nnp = NULL;
4927
4928 if (value != NULL)
4929 *nnp = g_variant_valist_get_nnp (str, value);
4930 else
4931 g_variant_format_string_scan (*str, NULL, str);
4932
4933 return;
4934 }
4935
4936 if (value != NULL)
4937 {
4938 switch (*(*str)++)
4939 {
4940 case 'b':
4941 *(gboolean *) ptr = g_variant_get_boolean (value);
4942 return;
4943
4944 case 'y':
4945 *(guchar *) ptr = g_variant_get_byte (value);
4946 return;
4947
4948 case 'n':
4949 *(gint16 *) ptr = g_variant_get_int16 (value);
4950 return;
4951
4952 case 'q':
4953 *(guint16 *) ptr = g_variant_get_uint16 (value);
4954 return;
4955
4956 case 'i':
4957 *(gint32 *) ptr = g_variant_get_int32 (value);
4958 return;
4959
4960 case 'u':
4961 *(guint32 *) ptr = g_variant_get_uint32 (value);
4962 return;
4963
4964 case 'x':
4965 *(gint64 *) ptr = g_variant_get_int64 (value);
4966 return;
4967
4968 case 't':
4969 *(guint64 *) ptr = g_variant_get_uint64 (value);
4970 return;
4971
4972 case 'h':
4973 *(gint32 *) ptr = g_variant_get_handle (value);
4974 return;
4975
4976 case 'd':
4977 *(gdouble *) ptr = g_variant_get_double (value);
4978 return;
4979 }
4980 }
4981 else
4982 {
4983 switch (*(*str)++)
4984 {
4985 case 'y':
4986 *(guchar *) ptr = 0;
4987 return;
4988
4989 case 'n':
4990 case 'q':
4991 *(guint16 *) ptr = 0;
4992 return;
4993
4994 case 'i':
4995 case 'u':
4996 case 'h':
4997 case 'b':
4998 *(guint32 *) ptr = 0;
4999 return;
5000
5001 case 'x':
5002 case 't':
5003 case 'd':
5004 *(guint64 *) ptr = 0;
5005 return;
5006 }
5007 }
5008
5009 g_assert_not_reached ();
5010 }
5011
5012 /* Generic (recursive) {{{2 */
5013 static void
5014 g_variant_valist_skip (const gchar **str,
5015 va_list *app)
5016 {
5017 if (g_variant_format_string_is_leaf (*str))
5018 g_variant_valist_skip_leaf (str, app);
5019
5020 else if (**str == 'm') /* maybe */
5021 {
5022 (*str)++;
5023
5024 if (!g_variant_format_string_is_nnp (*str))
5025 va_arg (*app, gboolean);
5026
5027 g_variant_valist_skip (str, app);
5028 }
5029 else /* tuple, dictionary entry */
5030 {
5031 g_assert (**str == '(' || **str == '{');
5032 (*str)++;
5033 while (**str != ')' && **str != '}')
5034 g_variant_valist_skip (str, app);
5035 (*str)++;
5036 }
5037 }
5038
5039 static GVariant *
5040 g_variant_valist_new (const gchar **str,
5041 va_list *app)
5042 {
5043 if (g_variant_format_string_is_leaf (*str))
5044 return g_variant_valist_new_leaf (str, app);
5045
5046 if (**str == 'm') /* maybe */
5047 {
5048 GVariantType *type = NULL;
5049 GVariant *value = NULL;
5050
5051 (*str)++;
5052
5053 if (g_variant_format_string_is_nnp (*str))
5054 {
5055 gpointer nnp = va_arg (*app, gpointer);
5056
5057 if (nnp != NULL)
5058 value = g_variant_valist_new_nnp (str, nnp);
5059 else
5060 type = g_variant_format_string_scan_type (*str, NULL, str);
5061 }
5062 else
5063 {
5064 gboolean just = va_arg (*app, gboolean);
5065
5066 if (just)
5067 value = g_variant_valist_new (str, app);
5068 else
5069 {
5070 type = g_variant_format_string_scan_type (*str, NULL, NULL);
5071 g_variant_valist_skip (str, app);
5072 }
5073 }
5074
5075 value = g_variant_new_maybe (type, value);
5076
5077 if (type != NULL)
5078 g_variant_type_free (type);
5079
5080 return value;
5081 }
5082 else /* tuple, dictionary entry */
5083 {
5084 GVariantBuilder b;
5085
5086 if (**str == '(')
5087 g_variant_builder_init (&b, G_VARIANT_TYPE_TUPLE);
5088 else
5089 {
5090 g_assert (**str == '{');
5091 g_variant_builder_init (&b, G_VARIANT_TYPE_DICT_ENTRY);
5092 }
5093
5094 (*str)++; /* '(' */
5095 while (**str != ')' && **str != '}')
5096 g_variant_builder_add_value (&b, g_variant_valist_new (str, app));
5097 (*str)++; /* ')' */
5098
5099 return g_variant_builder_end (&b);
5100 }
5101 }
5102
5103 static void
5104 g_variant_valist_get (const gchar **str,
5105 GVariant *value,
5106 gboolean free,
5107 va_list *app)
5108 {
5109 if (g_variant_format_string_is_leaf (*str))
5110 g_variant_valist_get_leaf (str, value, free, app);
5111
5112 else if (**str == 'm')
5113 {
5114 (*str)++;
5115
5116 if (value != NULL)
5117 value = g_variant_get_maybe (value);
5118
5119 if (!g_variant_format_string_is_nnp (*str))
5120 {
5121 gboolean *ptr = va_arg (*app, gboolean *);
5122
5123 if (ptr != NULL)
5124 *ptr = value != NULL;
5125 }
5126
5127 g_variant_valist_get (str, value, free, app);
5128
5129 if (value != NULL)
5130 g_variant_unref (value);
5131 }
5132
5133 else /* tuple, dictionary entry */
5134 {
5135 gint index = 0;
5136
5137 g_assert (**str == '(' || **str == '{');
5138
5139 (*str)++;
5140 while (**str != ')' && **str != '}')
5141 {
5142 if (value != NULL)
5143 {
5144 GVariant *child = g_variant_get_child_value (value, index++);
5145 g_variant_valist_get (str, child, free, app);
5146 g_variant_unref (child);
5147 }
5148 else
5149 g_variant_valist_get (str, NULL, free, app);
5150 }
5151 (*str)++;
5152 }
5153 }
5154
5155 /* User-facing API {{{2 */
5156 /**
5157 * g_variant_new: (skip)
5158 * @format_string: a #GVariant format string
5159 * @...: arguments, as per @format_string
5160 *
5161 * Creates a new #GVariant instance.
5162 *
5163 * Think of this function as an analogue to g_strdup_printf().
5164 *
5165 * The type of the created instance and the arguments that are expected
5166 * by this function are determined by @format_string. See the section on
5167 * [GVariant format strings][gvariant-format-strings]. Please note that
5168 * the syntax of the format string is very likely to be extended in the
5169 * future.
5170 *
5171 * The first character of the format string must not be '*' '?' '@' or
5172 * 'r'; in essence, a new #GVariant must always be constructed by this
5173 * function (and not merely passed through it unmodified).
5174 *
5175 * Note that the arguments must be of the correct width for their types
5176 * specified in @format_string. This can be achieved by casting them. See
5177 * the [GVariant varargs documentation][gvariant-varargs].
5178 *
5179 * |[<!-- language="C" -->
5180 * MyFlags some_flags = FLAG_ONE | FLAG_TWO;
5181 * const gchar *some_strings[] = { "a", "b", "c", NULL };
5182 * GVariant *new_variant;
5183 *
5184 * new_variant = g_variant_new ("(t^as)",
5185 * /<!-- -->* This cast is required. *<!-- -->/
5186 * (guint64) some_flags,
5187 * some_strings);
5188 * ]|
5189 *
5190 * Returns: a new floating #GVariant instance
5191 *
5192 * Since: 2.24
5193 **/
5194 GVariant *
5195 g_variant_new (const gchar *format_string,
5196 ...)
5197 {
5198 GVariant *value;
5199 va_list ap;
5200
5201 g_return_val_if_fail (valid_format_string (format_string, TRUE, NULL) &&
5202 format_string[0] != '?' && format_string[0] != '@' &&
5203 format_string[0] != '*' && format_string[0] != 'r',
5204 NULL);
5205
5206 va_start (ap, format_string);
5207 value = g_variant_new_va (format_string, NULL, &ap);
5208 va_end (ap);
5209
5210 return value;
5211 }
5212
5213 /**
5214 * g_variant_new_va: (skip)
5215 * @format_string: a string that is prefixed with a format string
5216 * @endptr: (allow-none) (default NULL): location to store the end pointer,
5217 * or %NULL
5218 * @app: a pointer to a #va_list
5219 *
5220 * This function is intended to be used by libraries based on
5221 * #GVariant that want to provide g_variant_new()-like functionality
5222 * to their users.
5223 *
5224 * The API is more general than g_variant_new() to allow a wider range
5225 * of possible uses.
5226 *
5227 * @format_string must still point to a valid format string, but it only
5228 * needs to be nul-terminated if @endptr is %NULL. If @endptr is
5229 * non-%NULL then it is updated to point to the first character past the
5230 * end of the format string.
5231 *
5232 * @app is a pointer to a #va_list. The arguments, according to
5233 * @format_string, are collected from this #va_list and the list is left
5234 * pointing to the argument following the last.
5235 *
5236 * Note that the arguments in @app must be of the correct width for their
5237 * types specified in @format_string when collected into the #va_list.
5238 * See the [GVariant varargs documentation][gvariant-varargs.
5239 *
5240 * These two generalisations allow mixing of multiple calls to
5241 * g_variant_new_va() and g_variant_get_va() within a single actual
5242 * varargs call by the user.
5243 *
5244 * The return value will be floating if it was a newly created GVariant
5245 * instance (for example, if the format string was "(ii)"). In the case
5246 * that the format_string was '*', '?', 'r', or a format starting with
5247 * '@' then the collected #GVariant pointer will be returned unmodified,
5248 * without adding any additional references.
5249 *
5250 * In order to behave correctly in all cases it is necessary for the
5251 * calling function to g_variant_ref_sink() the return result before
5252 * returning control to the user that originally provided the pointer.
5253 * At this point, the caller will have their own full reference to the
5254 * result. This can also be done by adding the result to a container,
5255 * or by passing it to another g_variant_new() call.
5256 *
5257 * Returns: a new, usually floating, #GVariant
5258 *
5259 * Since: 2.24
5260 **/
5261 GVariant *
5262 g_variant_new_va (const gchar *format_string,
5263 const gchar **endptr,
5264 va_list *app)
5265 {
5266 GVariant *value;
5267
5268 g_return_val_if_fail (valid_format_string (format_string, !endptr, NULL),
5269 NULL);
5270 g_return_val_if_fail (app != NULL, NULL);
5271
5272 value = g_variant_valist_new (&format_string, app);
5273
5274 if (endptr != NULL)
5275 *endptr = format_string;
5276
5277 return value;
5278 }
5279
5280 /**
5281 * g_variant_get: (skip)
5282 * @value: a #GVariant instance
5283 * @format_string: a #GVariant format string
5284 * @...: arguments, as per @format_string
5285 *
5286 * Deconstructs a #GVariant instance.
5287 *
5288 * Think of this function as an analogue to scanf().
5289 *
5290 * The arguments that are expected by this function are entirely
5291 * determined by @format_string. @format_string also restricts the
5292 * permissible types of @value. It is an error to give a value with
5293 * an incompatible type. See the section on
5294 * [GVariant format strings][gvariant-format-strings].
5295 * Please note that the syntax of the format string is very likely to be
5296 * extended in the future.
5297 *
5298 * @format_string determines the C types that are used for unpacking
5299 * the values and also determines if the values are copied or borrowed,
5300 * see the section on
5301 * [GVariant format strings][gvariant-format-strings-pointers].
5302 *
5303 * Since: 2.24
5304 **/
5305 void
5306 g_variant_get (GVariant *value,
5307 const gchar *format_string,
5308 ...)
5309 {
5310 va_list ap;
5311
5312 g_return_if_fail (valid_format_string (format_string, TRUE, value));
5313
5314 /* if any direct-pointer-access formats are in use, flatten first */
5315 if (strchr (format_string, '&'))
5316 g_variant_get_data (value);
5317
5318 va_start (ap, format_string);
5319 g_variant_get_va (value, format_string, NULL, &ap);
5320 va_end (ap);
5321 }
5322
5323 /**
5324 * g_variant_get_va: (skip)
5325 * @value: a #GVariant
5326 * @format_string: a string that is prefixed with a format string
5327 * @endptr: (allow-none) (default NULL): location to store the end pointer,
5328 * or %NULL
5329 * @app: a pointer to a #va_list
5330 *
5331 * This function is intended to be used by libraries based on #GVariant
5332 * that want to provide g_variant_get()-like functionality to their
5333 * users.
5334 *
5335 * The API is more general than g_variant_get() to allow a wider range
5336 * of possible uses.
5337 *
5338 * @format_string must still point to a valid format string, but it only
5339 * need to be nul-terminated if @endptr is %NULL. If @endptr is
5340 * non-%NULL then it is updated to point to the first character past the
5341 * end of the format string.
5342 *
5343 * @app is a pointer to a #va_list. The arguments, according to
5344 * @format_string, are collected from this #va_list and the list is left
5345 * pointing to the argument following the last.
5346 *
5347 * These two generalisations allow mixing of multiple calls to
5348 * g_variant_new_va() and g_variant_get_va() within a single actual
5349 * varargs call by the user.
5350 *
5351 * @format_string determines the C types that are used for unpacking
5352 * the values and also determines if the values are copied or borrowed,
5353 * see the section on
5354 * [GVariant format strings][gvariant-format-strings-pointers].
5355 *
5356 * Since: 2.24
5357 **/
5358 void
5359 g_variant_get_va (GVariant *value,
5360 const gchar *format_string,
5361 const gchar **endptr,
5362 va_list *app)
5363 {
5364 g_return_if_fail (valid_format_string (format_string, !endptr, value));
5365 g_return_if_fail (value != NULL);
5366 g_return_if_fail (app != NULL);
5367
5368 /* if any direct-pointer-access formats are in use, flatten first */
5369 if (strchr (format_string, '&'))
5370 g_variant_get_data (value);
5371
5372 g_variant_valist_get (&format_string, value, FALSE, app);
5373
5374 if (endptr != NULL)
5375 *endptr = format_string;
5376 }
5377
5378 /* Varargs-enabled Utility Functions {{{1 */
5379
5380 /**
5381 * g_variant_builder_add: (skip)
5382 * @builder: a #GVariantBuilder
5383 * @format_string: a #GVariant varargs format string
5384 * @...: arguments, as per @format_string
5385 *
5386 * Adds to a #GVariantBuilder.
5387 *
5388 * This call is a convenience wrapper that is exactly equivalent to
5389 * calling g_variant_new() followed by g_variant_builder_add_value().
5390 *
5391 * Note that the arguments must be of the correct width for their types
5392 * specified in @format_string. This can be achieved by casting them. See
5393 * the [GVariant varargs documentation][gvariant-varargs].
5394 *
5395 * This function might be used as follows:
5396 *
5397 * |[<!-- language="C" -->
5398 * GVariant *
5399 * make_pointless_dictionary (void)
5400 * {
5401 * GVariantBuilder builder;
5402 * int i;
5403 *
5404 * g_variant_builder_init (&builder, G_VARIANT_TYPE_ARRAY);
5405 * for (i = 0; i < 16; i++)
5406 * {
5407 * gchar buf[3];
5408 *
5409 * sprintf (buf, "%d", i);
5410 * g_variant_builder_add (&builder, "{is}", i, buf);
5411 * }
5412 *
5413 * return g_variant_builder_end (&builder);
5414 * }
5415 * ]|
5416 *
5417 * Since: 2.24
5418 */
5419 void
5420 g_variant_builder_add (GVariantBuilder *builder,
5421 const gchar *format_string,
5422 ...)
5423 {
5424 GVariant *variant;
5425 va_list ap;
5426
5427 va_start (ap, format_string);
5428 variant = g_variant_new_va (format_string, NULL, &ap);
5429 va_end (ap);
5430
5431 g_variant_builder_add_value (builder, variant);
5432 }
5433
5434 /**
5435 * g_variant_get_child: (skip)
5436 * @value: a container #GVariant
5437 * @index_: the index of the child to deconstruct
5438 * @format_string: a #GVariant format string
5439 * @...: arguments, as per @format_string
5440 *
5441 * Reads a child item out of a container #GVariant instance and
5442 * deconstructs it according to @format_string. This call is
5443 * essentially a combination of g_variant_get_child_value() and
5444 * g_variant_get().
5445 *
5446 * @format_string determines the C types that are used for unpacking
5447 * the values and also determines if the values are copied or borrowed,
5448 * see the section on
5449 * [GVariant format strings][gvariant-format-strings-pointers].
5450 *
5451 * Since: 2.24
5452 **/
5453 void
5454 g_variant_get_child (GVariant *value,
5455 gsize index_,
5456 const gchar *format_string,
5457 ...)
5458 {
5459 GVariant *child;
5460 va_list ap;
5461
5462 child = g_variant_get_child_value (value, index_);
5463 g_return_if_fail (valid_format_string (format_string, TRUE, child));
5464
5465 va_start (ap, format_string);
5466 g_variant_get_va (child, format_string, NULL, &ap);
5467 va_end (ap);
5468
5469 g_variant_unref (child);
5470 }
5471
5472 /**
5473 * g_variant_iter_next: (skip)
5474 * @iter: a #GVariantIter
5475 * @format_string: a GVariant format string
5476 * @...: the arguments to unpack the value into
5477 *
5478 * Gets the next item in the container and unpacks it into the variable
5479 * argument list according to @format_string, returning %TRUE.
5480 *
5481 * If no more items remain then %FALSE is returned.
5482 *
5483 * All of the pointers given on the variable arguments list of this
5484 * function are assumed to point at uninitialised memory. It is the
5485 * responsibility of the caller to free all of the values returned by
5486 * the unpacking process.
5487 *
5488 * Here is an example for memory management with g_variant_iter_next():
5489 * |[<!-- language="C" -->
5490 * // Iterates a dictionary of type 'a{sv}'
5491 * void
5492 * iterate_dictionary (GVariant *dictionary)
5493 * {
5494 * GVariantIter iter;
5495 * GVariant *value;
5496 * gchar *key;
5497 *
5498 * g_variant_iter_init (&iter, dictionary);
5499 * while (g_variant_iter_next (&iter, "{sv}", &key, &value))
5500 * {
5501 * g_print ("Item '%s' has type '%s'\n", key,
5502 * g_variant_get_type_string (value));
5503 *
5504 * // must free data for ourselves
5505 * g_variant_unref (value);
5506 * g_free (key);
5507 * }
5508 * }
5509 * ]|
5510 *
5511 * For a solution that is likely to be more convenient to C programmers
5512 * when dealing with loops, see g_variant_iter_loop().
5513 *
5514 * @format_string determines the C types that are used for unpacking
5515 * the values and also determines if the values are copied or borrowed.
5516 *
5517 * See the section on
5518 * [GVariant format strings][gvariant-format-strings-pointers].
5519 *
5520 * Returns: %TRUE if a value was unpacked, or %FALSE if there as no value
5521 *
5522 * Since: 2.24
5523 **/
5524 gboolean
5525 g_variant_iter_next (GVariantIter *iter,
5526 const gchar *format_string,
5527 ...)
5528 {
5529 GVariant *value;
5530
5531 value = g_variant_iter_next_value (iter);
5532
5533 g_return_val_if_fail (valid_format_string (format_string, TRUE, value),
5534 FALSE);
5535
5536 if (value != NULL)
5537 {
5538 va_list ap;
5539
5540 va_start (ap, format_string);
5541 g_variant_valist_get (&format_string, value, FALSE, &ap);
5542 va_end (ap);
5543
5544 g_variant_unref (value);
5545 }
5546
5547 return value != NULL;
5548 }
5549
5550 /**
5551 * g_variant_iter_loop: (skip)
5552 * @iter: a #GVariantIter
5553 * @format_string: a GVariant format string
5554 * @...: the arguments to unpack the value into
5555 *
5556 * Gets the next item in the container and unpacks it into the variable
5557 * argument list according to @format_string, returning %TRUE.
5558 *
5559 * If no more items remain then %FALSE is returned.
5560 *
5561 * On the first call to this function, the pointers appearing on the
5562 * variable argument list are assumed to point at uninitialised memory.
5563 * On the second and later calls, it is assumed that the same pointers
5564 * will be given and that they will point to the memory as set by the
5565 * previous call to this function. This allows the previous values to
5566 * be freed, as appropriate.
5567 *
5568 * This function is intended to be used with a while loop as
5569 * demonstrated in the following example. This function can only be
5570 * used when iterating over an array. It is only valid to call this
5571 * function with a string constant for the format string and the same
5572 * string constant must be used each time. Mixing calls to this
5573 * function and g_variant_iter_next() or g_variant_iter_next_value() on
5574 * the same iterator causes undefined behavior.
5575 *
5576 * If you break out of a such a while loop using g_variant_iter_loop() then
5577 * you must free or unreference all the unpacked values as you would with
5578 * g_variant_get(). Failure to do so will cause a memory leak.
5579 *
5580 * Here is an example for memory management with g_variant_iter_loop():
5581 * |[<!-- language="C" -->
5582 * // Iterates a dictionary of type 'a{sv}'
5583 * void
5584 * iterate_dictionary (GVariant *dictionary)
5585 * {
5586 * GVariantIter iter;
5587 * GVariant *value;
5588 * gchar *key;
5589 *
5590 * g_variant_iter_init (&iter, dictionary);
5591 * while (g_variant_iter_loop (&iter, "{sv}", &key, &value))
5592 * {
5593 * g_print ("Item '%s' has type '%s'\n", key,
5594 * g_variant_get_type_string (value));
5595 *
5596 * // no need to free 'key' and 'value' here
5597 * // unless breaking out of this loop
5598 * }
5599 * }
5600 * ]|
5601 *
5602 * For most cases you should use g_variant_iter_next().
5603 *
5604 * This function is really only useful when unpacking into #GVariant or
5605 * #GVariantIter in order to allow you to skip the call to
5606 * g_variant_unref() or g_variant_iter_free().
5607 *
5608 * For example, if you are only looping over simple integer and string
5609 * types, g_variant_iter_next() is definitely preferred. For string
5610 * types, use the '&' prefix to avoid allocating any memory at all (and
5611 * thereby avoiding the need to free anything as well).
5612 *
5613 * @format_string determines the C types that are used for unpacking
5614 * the values and also determines if the values are copied or borrowed.
5615 *
5616 * See the section on
5617 * [GVariant format strings][gvariant-format-strings-pointers].
5618 *
5619 * Returns: %TRUE if a value was unpacked, or %FALSE if there was no
5620 * value
5621 *
5622 * Since: 2.24
5623 **/
5624 gboolean
5625 g_variant_iter_loop (GVariantIter *iter,
5626 const gchar *format_string,
5627 ...)
5628 {
5629 gboolean first_time = GVSI(iter)->loop_format == NULL;
5630 GVariant *value;
5631 va_list ap;
5632
5633 g_return_val_if_fail (first_time ||
5634 format_string == GVSI(iter)->loop_format,
5635 FALSE);
5636
5637 if (first_time)
5638 {
5639 TYPE_CHECK (GVSI(iter)->value, G_VARIANT_TYPE_ARRAY, FALSE);
5640 GVSI(iter)->loop_format = format_string;
5641
5642 if (strchr (format_string, '&'))
5643 g_variant_get_data (GVSI(iter)->value);
5644 }
5645
5646 value = g_variant_iter_next_value (iter);
5647
5648 g_return_val_if_fail (!first_time ||
5649 valid_format_string (format_string, TRUE, value),
5650 FALSE);
5651
5652 va_start (ap, format_string);
5653 g_variant_valist_get (&format_string, value, !first_time, &ap);
5654 va_end (ap);
5655
5656 if (value != NULL)
5657 g_variant_unref (value);
5658
5659 return value != NULL;
5660 }
5661
5662 /* Serialised data {{{1 */
5663 static GVariant *
5664 g_variant_deep_copy (GVariant *value)
5665 {
5666 switch (g_variant_classify (value))
5667 {
5668 case G_VARIANT_CLASS_MAYBE:
5669 case G_VARIANT_CLASS_ARRAY:
5670 case G_VARIANT_CLASS_TUPLE:
5671 case G_VARIANT_CLASS_DICT_ENTRY:
5672 case G_VARIANT_CLASS_VARIANT:
5673 {
5674 GVariantBuilder builder;
5675 GVariantIter iter;
5676 GVariant *child;
5677
5678 g_variant_builder_init (&builder, g_variant_get_type (value));
5679 g_variant_iter_init (&iter, value);
5680
5681 while ((child = g_variant_iter_next_value (&iter)))
5682 {
5683 g_variant_builder_add_value (&builder, g_variant_deep_copy (child));
5684 g_variant_unref (child);
5685 }
5686
5687 return g_variant_builder_end (&builder);
5688 }
5689
5690 case G_VARIANT_CLASS_BOOLEAN:
5691 return g_variant_new_boolean (g_variant_get_boolean (value));
5692
5693 case G_VARIANT_CLASS_BYTE:
5694 return g_variant_new_byte (g_variant_get_byte (value));
5695
5696 case G_VARIANT_CLASS_INT16:
5697 return g_variant_new_int16 (g_variant_get_int16 (value));
5698
5699 case G_VARIANT_CLASS_UINT16:
5700 return g_variant_new_uint16 (g_variant_get_uint16 (value));
5701
5702 case G_VARIANT_CLASS_INT32:
5703 return g_variant_new_int32 (g_variant_get_int32 (value));
5704
5705 case G_VARIANT_CLASS_UINT32:
5706 return g_variant_new_uint32 (g_variant_get_uint32 (value));
5707
5708 case G_VARIANT_CLASS_INT64:
5709 return g_variant_new_int64 (g_variant_get_int64 (value));
5710
5711 case G_VARIANT_CLASS_UINT64:
5712 return g_variant_new_uint64 (g_variant_get_uint64 (value));
5713
5714 case G_VARIANT_CLASS_HANDLE:
5715 return g_variant_new_handle (g_variant_get_handle (value));
5716
5717 case G_VARIANT_CLASS_DOUBLE:
5718 return g_variant_new_double (g_variant_get_double (value));
5719
5720 case G_VARIANT_CLASS_STRING:
5721 return g_variant_new_string (g_variant_get_string (value, NULL));
5722
5723 case G_VARIANT_CLASS_OBJECT_PATH:
5724 return g_variant_new_object_path (g_variant_get_string (value, NULL));
5725
5726 case G_VARIANT_CLASS_SIGNATURE:
5727 return g_variant_new_signature (g_variant_get_string (value, NULL));
5728 }
5729
5730 g_assert_not_reached ();
5731 }
5732
5733 /**
5734 * g_variant_get_normal_form:
5735 * @value: a #GVariant
5736 *
5737 * Gets a #GVariant instance that has the same value as @value and is
5738 * trusted to be in normal form.
5739 *
5740 * If @value is already trusted to be in normal form then a new
5741 * reference to @value is returned.
5742 *
5743 * If @value is not already trusted, then it is scanned to check if it
5744 * is in normal form. If it is found to be in normal form then it is
5745 * marked as trusted and a new reference to it is returned.
5746 *
5747 * If @value is found not to be in normal form then a new trusted
5748 * #GVariant is created with the same value as @value.
5749 *
5750 * It makes sense to call this function if you've received #GVariant
5751 * data from untrusted sources and you want to ensure your serialised
5752 * output is definitely in normal form.
5753 *
5754 * Returns: (transfer full): a trusted #GVariant
5755 *
5756 * Since: 2.24
5757 **/
5758 GVariant *
5759 g_variant_get_normal_form (GVariant *value)
5760 {
5761 GVariant *trusted;
5762
5763 if (g_variant_is_normal_form (value))
5764 return g_variant_ref (value);
5765
5766 trusted = g_variant_deep_copy (value);
5767 g_assert (g_variant_is_trusted (trusted));
5768
5769 return g_variant_ref_sink (trusted);
5770 }
5771
5772 /**
5773 * g_variant_byteswap:
5774 * @value: a #GVariant
5775 *
5776 * Performs a byteswapping operation on the contents of @value. The
5777 * result is that all multi-byte numeric data contained in @value is
5778 * byteswapped. That includes 16, 32, and 64bit signed and unsigned
5779 * integers as well as file handles and double precision floating point
5780 * values.
5781 *
5782 * This function is an identity mapping on any value that does not
5783 * contain multi-byte numeric data. That include strings, booleans,
5784 * bytes and containers containing only these things (recursively).
5785 *
5786 * The returned value is always in normal form and is marked as trusted.
5787 *
5788 * Returns: (transfer full): the byteswapped form of @value
5789 *
5790 * Since: 2.24
5791 **/
5792 GVariant *
5793 g_variant_byteswap (GVariant *value)
5794 {
5795 GVariantTypeInfo *type_info;
5796 guint alignment;
5797 GVariant *new;
5798
5799 type_info = g_variant_get_type_info (value);
5800
5801 g_variant_type_info_query (type_info, &alignment, NULL);
5802
5803 if (alignment)
5804 /* (potentially) contains multi-byte numeric data */
5805 {
5806 GVariantSerialised serialised;
5807 GVariant *trusted;
5808 GBytes *bytes;
5809
5810 trusted = g_variant_get_normal_form (value);
5811 serialised.type_info = g_variant_get_type_info (trusted);
5812 serialised.size = g_variant_get_size (trusted);
5813 serialised.data = g_malloc (serialised.size);
5814 g_variant_store (trusted, serialised.data);
5815 g_variant_unref (trusted);
5816
5817 g_variant_serialised_byteswap (serialised);
5818
5819 bytes = g_bytes_new_take (serialised.data, serialised.size);
5820 #ifdef GSTREAMER_LITE
5821 if (bytes == NULL) {
5822 return NULL;
5823 }
5824 #endif // GSTREAMER_LITE
5825 new = g_variant_new_from_bytes (g_variant_get_type (value), bytes, TRUE);
5826 g_bytes_unref (bytes);
5827 }
5828 else
5829 /* contains no multi-byte data */
5830 new = value;
5831
5832 return g_variant_ref_sink (new);
5833 }
5834
5835 /**
5836 * g_variant_new_from_data:
5837 * @type: a definite #GVariantType
5838 * @data: (array length=size) (element-type guint8): the serialised data
5839 * @size: the size of @data
5840 * @trusted: %TRUE if @data is definitely in normal form
5841 * @notify: (scope async): function to call when @data is no longer needed
5842 * @user_data: data for @notify
5843 *
5844 * Creates a new #GVariant instance from serialised data.
5845 *
5846 * @type is the type of #GVariant instance that will be constructed.
5847 * The interpretation of @data depends on knowing the type.
5848 *
5849 * @data is not modified by this function and must remain valid with an
5850 * unchanging value until such a time as @notify is called with
5851 * @user_data. If the contents of @data change before that time then
5852 * the result is undefined.
5853 *
5854 * If @data is trusted to be serialised data in normal form then
5855 * @trusted should be %TRUE. This applies to serialised data created
5856 * within this process or read from a trusted location on the disk (such
5857 * as a file installed in /usr/lib alongside your application). You
5858 * should set trusted to %FALSE if @data is read from the network, a
5859 * file in the user's home directory, etc.
5860 *
5861 * If @data was not stored in this machine's native endianness, any multi-byte
5862 * numeric values in the returned variant will also be in non-native
5863 * endianness. g_variant_byteswap() can be used to recover the original values.
5864 *
5865 * @notify will be called with @user_data when @data is no longer
5866 * needed. The exact time of this call is unspecified and might even be
5867 * before this function returns.
5868 *
5869 * Returns: (transfer none): a new floating #GVariant of type @type
5870 *
5871 * Since: 2.24
5872 **/
5873 GVariant *
5874 g_variant_new_from_data (const GVariantType *type,
5875 gconstpointer data,
5876 gsize size,
5877 gboolean trusted,
5878 GDestroyNotify notify,
5879 gpointer user_data)
5880 {
5881 GVariant *value;
5882 GBytes *bytes;
5883
5884 g_return_val_if_fail (g_variant_type_is_definite (type), NULL);
5885 g_return_val_if_fail (data != NULL || size == 0, NULL);
5886
5887 if (notify)
5888 bytes = g_bytes_new_with_free_func (data, size, notify, user_data);
5889 else
5890 bytes = g_bytes_new_static (data, size);
5891
5892 value = g_variant_new_from_bytes (type, bytes, trusted);
5893 g_bytes_unref (bytes);
5894
5895 return value;
5896 }
5897
5898 /* Epilogue {{{1 */
5899 /* vim:set foldmethod=marker: */