1/*	$NetBSD: prop_array.c,v 1.20 2008/08/11 05:54:21 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2006, 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <prop/prop_array.h>
33#include "prop_object_impl.h"
34
35#if !defined(_KERNEL) && !defined(_STANDALONE)
36#include <errno.h>
37#endif
38
39struct _prop_array {
40	struct _prop_object	pa_obj;
41	_PROP_RWLOCK_DECL(pa_rwlock)
42	prop_object_t *		pa_array;
43	unsigned int		pa_capacity;
44	unsigned int		pa_count;
45	int			pa_flags;
46
47	uint32_t		pa_version;
48};
49
50#define PA_F_IMMUTABLE		0x01	/* array is immutable */
51
52_PROP_POOL_INIT(_prop_array_pool, sizeof(struct _prop_array), "proparay")
53_PROP_MALLOC_DEFINE(M_PROP_ARRAY, "prop array",
54		    "property array container object")
55
56static _prop_object_free_rv_t
57		_prop_array_free(prop_stack_t, prop_object_t *);
58static void	_prop_array_emergency_free(prop_object_t);
59static bool	_prop_array_externalize(
60				struct _prop_object_externalize_context *,
61				void *);
62static _prop_object_equals_rv_t
63		_prop_array_equals(prop_object_t, prop_object_t,
64				   void **, void **,
65				   prop_object_t *, prop_object_t *);
66static void	_prop_array_equals_finish(prop_object_t, prop_object_t);
67static prop_object_iterator_t
68		_prop_array_iterator_locked(prop_array_t);
69static prop_object_t
70		_prop_array_iterator_next_object_locked(void *);
71static void	_prop_array_iterator_reset_locked(void *);
72
73static const struct _prop_object_type _prop_object_type_array = {
74	.pot_type		=	PROP_TYPE_ARRAY,
75	.pot_free		=	_prop_array_free,
76	.pot_emergency_free	=	_prop_array_emergency_free,
77	.pot_extern		=	_prop_array_externalize,
78	.pot_equals		=	_prop_array_equals,
79	.pot_equals_finish	=	_prop_array_equals_finish,
80};
81
82#define prop_object_is_array(x)		\
83	((x) != NULL && (x)->pa_obj.po_type == &_prop_object_type_array)
84
85#define prop_array_is_immutable(x) (((x)->pa_flags & PA_F_IMMUTABLE) != 0)
86
87struct _prop_array_iterator {
88	struct _prop_object_iterator pai_base;
89	unsigned int		pai_index;
90};
91
92#define EXPAND_STEP		16
93
94static _prop_object_free_rv_t
95_prop_array_free(prop_stack_t stack, prop_object_t *obj)
96{
97	prop_array_t pa = *obj;
98	prop_object_t po;
99
100	_PROP_ASSERT(pa->pa_count <= pa->pa_capacity);
101	_PROP_ASSERT((pa->pa_capacity == 0 && pa->pa_array == NULL) ||
102		     (pa->pa_capacity != 0 && pa->pa_array != NULL));
103
104	/* The easy case is an empty array, just free and return. */
105	if (pa->pa_count == 0) {
106		if (pa->pa_array != NULL)
107			_PROP_FREE(pa->pa_array, M_PROP_ARRAY);
108
109		_PROP_RWLOCK_DESTROY(pa->pa_rwlock);
110
111		_PROP_POOL_PUT(_prop_array_pool, pa);
112
113		return (_PROP_OBJECT_FREE_DONE);
114	}
115
116	po = pa->pa_array[pa->pa_count - 1];
117	_PROP_ASSERT(po != NULL);
118
119	if (stack == NULL) {
120		/*
121		 * If we are in emergency release mode,
122		 * just let caller recurse down.
123		 */
124		*obj = po;
125		return (_PROP_OBJECT_FREE_FAILED);
126	}
127
128	/* Otherwise, try to push the current object on the stack. */
129	if (!_prop_stack_push(stack, pa, NULL, NULL, NULL)) {
130		/* Push failed, entering emergency release mode. */
131		return (_PROP_OBJECT_FREE_FAILED);
132	}
133	/* Object pushed on stack, caller will release it. */
134	--pa->pa_count;
135	*obj = po;
136	return (_PROP_OBJECT_FREE_RECURSE);
137}
138
139static void
140_prop_array_emergency_free(prop_object_t obj)
141{
142	prop_array_t pa = obj;
143
144	_PROP_ASSERT(pa->pa_count != 0);
145	--pa->pa_count;
146}
147
148static bool
149_prop_array_externalize(struct _prop_object_externalize_context *ctx,
150			void *v)
151{
152	prop_array_t pa = v;
153	struct _prop_object *po;
154	prop_object_iterator_t pi;
155	unsigned int i;
156	bool rv = false;
157
158	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
159
160	if (pa->pa_count == 0) {
161		_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
162		return (_prop_object_externalize_empty_tag(ctx, "array"));
163	}
164
165	/* XXXJRT Hint "count" for the internalize step? */
166	if (_prop_object_externalize_start_tag(ctx, "array") == false ||
167	    _prop_object_externalize_append_char(ctx, '\n') == false)
168		goto out;
169
170	pi = _prop_array_iterator_locked(pa);
171	if (pi == NULL)
172		goto out;
173
174	ctx->poec_depth++;
175	_PROP_ASSERT(ctx->poec_depth != 0);
176
177	while ((po = _prop_array_iterator_next_object_locked(pi)) != NULL) {
178		if ((*po->po_type->pot_extern)(ctx, po) == false) {
179			prop_object_iterator_release(pi);
180			goto out;
181		}
182	}
183
184	prop_object_iterator_release(pi);
185
186	ctx->poec_depth--;
187	for (i = 0; i < ctx->poec_depth; i++) {
188		if (_prop_object_externalize_append_char(ctx, '\t') == false)
189			goto out;
190	}
191	if (_prop_object_externalize_end_tag(ctx, "array") == false)
192		goto out;
193
194	rv = true;
195
196 out:
197	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
198	return (rv);
199}
200
201/* ARGSUSED */
202static _prop_object_equals_rv_t
203_prop_array_equals(prop_object_t v1, prop_object_t v2,
204    void **stored_pointer1, void **stored_pointer2,
205    prop_object_t *next_obj1, prop_object_t *next_obj2)
206{
207	prop_array_t array1 = v1;
208	prop_array_t array2 = v2;
209	uintptr_t idx;
210	_prop_object_equals_rv_t rv = _PROP_OBJECT_EQUALS_FALSE;
211
212	if (array1 == array2)
213		return (_PROP_OBJECT_EQUALS_TRUE);
214
215	_PROP_ASSERT(*stored_pointer1 == *stored_pointer2);
216	idx = (uintptr_t)*stored_pointer1;
217
218	/* For the first iteration, lock the objects. */
219	if (idx == 0) {
220		if ((uintptr_t)array1 < (uintptr_t)array2) {
221			_PROP_RWLOCK_RDLOCK(array1->pa_rwlock);
222			_PROP_RWLOCK_RDLOCK(array2->pa_rwlock);
223		} else {
224			_PROP_RWLOCK_RDLOCK(array2->pa_rwlock);
225			_PROP_RWLOCK_RDLOCK(array1->pa_rwlock);
226		}
227	}
228
229	if (array1->pa_count != array2->pa_count)
230		goto out;
231	if (idx == array1->pa_count) {
232		rv = _PROP_OBJECT_EQUALS_TRUE;
233		goto out;
234	}
235	_PROP_ASSERT(idx < array1->pa_count);
236
237	*stored_pointer1 = (void *)(idx + 1);
238	*stored_pointer2 = (void *)(idx + 1);
239
240	*next_obj1 = array1->pa_array[idx];
241	*next_obj2 = array2->pa_array[idx];
242
243	return (_PROP_OBJECT_EQUALS_RECURSE);
244
245 out:
246	_PROP_RWLOCK_UNLOCK(array1->pa_rwlock);
247	_PROP_RWLOCK_UNLOCK(array2->pa_rwlock);
248	return (rv);
249}
250
251static void
252_prop_array_equals_finish(prop_object_t v1, prop_object_t v2)
253{
254	_PROP_RWLOCK_UNLOCK(((prop_array_t)v1)->pa_rwlock);
255	_PROP_RWLOCK_UNLOCK(((prop_array_t)v2)->pa_rwlock);
256}
257
258static prop_array_t
259_prop_array_alloc(unsigned int capacity)
260{
261	prop_array_t pa;
262	prop_object_t *array;
263
264	if (capacity != 0) {
265		array = _PROP_CALLOC(capacity * sizeof(prop_object_t),
266				     M_PROP_ARRAY);
267		if (array == NULL)
268			return (NULL);
269	} else
270		array = NULL;
271
272	pa = _PROP_POOL_GET(_prop_array_pool);
273	if (pa != NULL) {
274		_prop_object_init(&pa->pa_obj, &_prop_object_type_array);
275		pa->pa_obj.po_type = &_prop_object_type_array;
276
277		_PROP_RWLOCK_INIT(pa->pa_rwlock);
278		pa->pa_array = array;
279		pa->pa_capacity = capacity;
280		pa->pa_count = 0;
281		pa->pa_flags = 0;
282
283		pa->pa_version = 0;
284	} else if (array != NULL)
285		_PROP_FREE(array, M_PROP_ARRAY);
286
287	return (pa);
288}
289
290static bool
291_prop_array_expand(prop_array_t pa, unsigned int capacity)
292{
293	prop_object_t *array, *oarray;
294
295	/*
296	 * Array must be WRITE-LOCKED.
297	 */
298
299	oarray = pa->pa_array;
300
301	array = _PROP_CALLOC(capacity * sizeof(*array), M_PROP_ARRAY);
302	if (array == NULL)
303		return (false);
304	if (oarray != NULL)
305		memcpy(array, oarray, pa->pa_capacity * sizeof(*array));
306	pa->pa_array = array;
307	pa->pa_capacity = capacity;
308
309	if (oarray != NULL)
310		_PROP_FREE(oarray, M_PROP_ARRAY);
311
312	return (true);
313}
314
315static prop_object_t
316_prop_array_iterator_next_object_locked(void *v)
317{
318	struct _prop_array_iterator *pai = v;
319	prop_array_t pa = pai->pai_base.pi_obj;
320	prop_object_t po = NULL;
321
322	_PROP_ASSERT(prop_object_is_array(pa));
323
324	if (pa->pa_version != pai->pai_base.pi_version)
325		goto out;	/* array changed during iteration */
326
327	_PROP_ASSERT(pai->pai_index <= pa->pa_count);
328
329	if (pai->pai_index == pa->pa_count)
330		goto out;	/* we've iterated all objects */
331
332	po = pa->pa_array[pai->pai_index];
333	pai->pai_index++;
334
335 out:
336	return (po);
337}
338
339static prop_object_t
340_prop_array_iterator_next_object(void *v)
341{
342	struct _prop_array_iterator *pai = v;
343	prop_array_t pa __unused = pai->pai_base.pi_obj;
344	prop_object_t po;
345
346	_PROP_ASSERT(prop_object_is_array(pa));
347
348	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
349	po = _prop_array_iterator_next_object_locked(pai);
350	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
351	return (po);
352}
353
354static void
355_prop_array_iterator_reset_locked(void *v)
356{
357	struct _prop_array_iterator *pai = v;
358	prop_array_t pa = pai->pai_base.pi_obj;
359
360	_PROP_ASSERT(prop_object_is_array(pa));
361
362	pai->pai_index = 0;
363	pai->pai_base.pi_version = pa->pa_version;
364}
365
366static void
367_prop_array_iterator_reset(void *v)
368{
369	struct _prop_array_iterator *pai = v;
370	prop_array_t pa __unused = pai->pai_base.pi_obj;
371
372	_PROP_ASSERT(prop_object_is_array(pa));
373
374	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
375	_prop_array_iterator_reset_locked(pai);
376	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
377}
378
379/*
380 * prop_array_create --
381 *	Create an empty array.
382 */
383prop_array_t
384prop_array_create(void)
385{
386
387	return (_prop_array_alloc(0));
388}
389
390/*
391 * prop_array_create_with_capacity --
392 *	Create an array with the capacity to store N objects.
393 */
394prop_array_t
395prop_array_create_with_capacity(unsigned int capacity)
396{
397
398	return (_prop_array_alloc(capacity));
399}
400
401/*
402 * prop_array_copy --
403 *	Copy an array.	The new array has an initial capacity equal to
404 *	the number of objects stored in the original array.  The new
405 *	array contains references to the original array's objects, not
406 *	copies of those objects (i.e. a shallow copy).
407 */
408prop_array_t
409prop_array_copy(prop_array_t opa)
410{
411	prop_array_t pa;
412	prop_object_t po;
413	unsigned int idx;
414
415	if (! prop_object_is_array(opa))
416		return (NULL);
417
418	_PROP_RWLOCK_RDLOCK(opa->pa_rwlock);
419
420	pa = _prop_array_alloc(opa->pa_count);
421	if (pa != NULL) {
422		for (idx = 0; idx < opa->pa_count; idx++) {
423			po = opa->pa_array[idx];
424			prop_object_retain(po);
425			pa->pa_array[idx] = po;
426		}
427		pa->pa_count = opa->pa_count;
428		pa->pa_flags = opa->pa_flags;
429	}
430	_PROP_RWLOCK_UNLOCK(opa->pa_rwlock);
431	return (pa);
432}
433
434/*
435 * prop_array_copy_mutable --
436 *	Like prop_array_copy(), but the resulting array is mutable.
437 */
438prop_array_t
439prop_array_copy_mutable(prop_array_t opa)
440{
441	prop_array_t pa;
442
443	pa = prop_array_copy(opa);
444	if (pa != NULL)
445		pa->pa_flags &= ~PA_F_IMMUTABLE;
446
447	return (pa);
448}
449
450/*
451 * prop_array_capacity --
452 *	Return the capacity of the array.
453 */
454unsigned int
455prop_array_capacity(prop_array_t pa)
456{
457	unsigned int rv;
458
459	if (! prop_object_is_array(pa))
460		return (0);
461
462	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
463	rv = pa->pa_capacity;
464	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
465
466	return (rv);
467}
468
469/*
470 * prop_array_count --
471 *	Return the number of objects stored in the array.
472 */
473unsigned int
474prop_array_count(prop_array_t pa)
475{
476	unsigned int rv;
477
478	if (! prop_object_is_array(pa))
479		return (0);
480
481	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
482	rv = pa->pa_count;
483	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
484
485	return (rv);
486}
487
488/*
489 * prop_array_ensure_capacity --
490 *	Ensure that the array has the capacity to store the specified
491 *	total number of objects (inluding the objects already stored
492 *	in the array).
493 */
494bool
495prop_array_ensure_capacity(prop_array_t pa, unsigned int capacity)
496{
497	bool rv;
498
499	if (! prop_object_is_array(pa))
500		return (false);
501
502	_PROP_RWLOCK_WRLOCK(pa->pa_rwlock);
503	if (capacity > pa->pa_capacity)
504		rv = _prop_array_expand(pa, capacity);
505	else
506		rv = true;
507	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
508
509	return (rv);
510}
511
512static prop_object_iterator_t
513_prop_array_iterator_locked(prop_array_t pa)
514{
515	struct _prop_array_iterator *pai;
516
517	if (! prop_object_is_array(pa))
518		return (NULL);
519
520	pai = _PROP_CALLOC(sizeof(*pai), M_TEMP);
521	if (pai == NULL)
522		return (NULL);
523	pai->pai_base.pi_next_object = _prop_array_iterator_next_object;
524	pai->pai_base.pi_reset = _prop_array_iterator_reset;
525	prop_object_retain(pa);
526	pai->pai_base.pi_obj = pa;
527	_prop_array_iterator_reset_locked(pai);
528
529	return (&pai->pai_base);
530}
531
532/*
533 * prop_array_iterator --
534 *	Return an iterator for the array.  The array is retained by
535 *	the iterator.
536 */
537prop_object_iterator_t
538prop_array_iterator(prop_array_t pa)
539{
540	prop_object_iterator_t pi;
541
542	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
543	pi = _prop_array_iterator_locked(pa);
544	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
545	return (pi);
546}
547
548/*
549 * prop_array_make_immutable --
550 *	Make the array immutable.
551 */
552void
553prop_array_make_immutable(prop_array_t pa)
554{
555
556	_PROP_RWLOCK_WRLOCK(pa->pa_rwlock);
557	if (prop_array_is_immutable(pa) == false)
558		pa->pa_flags |= PA_F_IMMUTABLE;
559	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
560}
561
562/*
563 * prop_array_mutable --
564 *	Returns true if the array is mutable.
565 */
566bool
567prop_array_mutable(prop_array_t pa)
568{
569	bool rv;
570
571	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
572	rv = prop_array_is_immutable(pa) == false;
573	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
574
575	return (rv);
576}
577
578/*
579 * prop_array_get --
580 *	Return the object stored at the specified array index.
581 */
582prop_object_t
583prop_array_get(prop_array_t pa, unsigned int idx)
584{
585	prop_object_t po = NULL;
586
587	if (! prop_object_is_array(pa))
588		return (NULL);
589
590	_PROP_RWLOCK_RDLOCK(pa->pa_rwlock);
591	if (idx >= pa->pa_count)
592		goto out;
593	po = pa->pa_array[idx];
594	_PROP_ASSERT(po != NULL);
595 out:
596	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
597	return (po);
598}
599
600static bool
601_prop_array_add(prop_array_t pa, prop_object_t po)
602{
603
604	/*
605	 * Array must be WRITE-LOCKED.
606	 */
607
608	_PROP_ASSERT(pa->pa_count <= pa->pa_capacity);
609
610	if (prop_array_is_immutable(pa) ||
611	    (pa->pa_count == pa->pa_capacity &&
612	    _prop_array_expand(pa, pa->pa_capacity + EXPAND_STEP) == false))
613		return (false);
614
615	prop_object_retain(po);
616	pa->pa_array[pa->pa_count++] = po;
617	pa->pa_version++;
618
619	return (true);
620}
621
622/*
623 * prop_array_set --
624 *	Store a reference to an object at the specified array index.
625 *	This method is not allowed to create holes in the array; the
626 *	caller must either be setting the object just beyond the existing
627 *	count or replacing an already existing object reference.
628 */
629bool
630prop_array_set(prop_array_t pa, unsigned int idx, prop_object_t po)
631{
632	prop_object_t opo;
633	bool rv = false;
634
635	if (! prop_object_is_array(pa))
636		return (false);
637
638	_PROP_RWLOCK_WRLOCK(pa->pa_rwlock);
639
640	if (prop_array_is_immutable(pa))
641		goto out;
642
643	if (idx == pa->pa_count) {
644		rv = _prop_array_add(pa, po);
645		goto out;
646	}
647
648	_PROP_ASSERT(idx < pa->pa_count);
649
650	opo = pa->pa_array[idx];
651	_PROP_ASSERT(opo != NULL);
652
653	prop_object_retain(po);
654	pa->pa_array[idx] = po;
655	pa->pa_version++;
656
657	prop_object_release(opo);
658
659	rv = true;
660
661 out:
662	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
663	return (rv);
664}
665
666/*
667 * prop_array_add --
668 *	Add a reference to an object to the specified array, appending
669 *	to the end and growing the array's capacity, if necessary.
670 */
671bool
672prop_array_add(prop_array_t pa, prop_object_t po)
673{
674	bool rv;
675
676	if (! prop_object_is_array(pa))
677		return (false);
678
679	_PROP_RWLOCK_WRLOCK(pa->pa_rwlock);
680	rv = _prop_array_add(pa, po);
681	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
682
683	return (rv);
684}
685
686/*
687 * prop_array_remove --
688 *	Remove the reference to an object from an array at the specified
689 *	index.	The array will be compacted following the removal.
690 */
691void
692prop_array_remove(prop_array_t pa, unsigned int idx)
693{
694	prop_object_t po;
695
696	if (! prop_object_is_array(pa))
697		return;
698
699	_PROP_RWLOCK_WRLOCK(pa->pa_rwlock);
700
701	_PROP_ASSERT(idx < pa->pa_count);
702
703	/* XXX Should this be a _PROP_ASSERT()? */
704	if (prop_array_is_immutable(pa)) {
705		_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
706		return;
707	}
708
709	po = pa->pa_array[idx];
710	_PROP_ASSERT(po != NULL);
711
712	for (++idx; idx < pa->pa_count; idx++)
713		pa->pa_array[idx - 1] = pa->pa_array[idx];
714	pa->pa_count--;
715	pa->pa_version++;
716
717	_PROP_RWLOCK_UNLOCK(pa->pa_rwlock);
718
719	prop_object_release(po);
720}
721
722/*
723 * prop_array_equals --
724 *	Return true if the two arrays are equivalent.  Note we do a
725 *	by-value comparison of the objects in the array.
726 */
727bool
728prop_array_equals(prop_array_t array1, prop_array_t array2)
729{
730	if (!prop_object_is_array(array1) || !prop_object_is_array(array2))
731		return (false);
732
733	return (prop_object_equals(array1, array2));
734}
735
736/*
737 * prop_array_externalize --
738 *	Externalize an array, return a NUL-terminated buffer
739 *	containing the XML-style representation.  The buffer is allocated
740 *	with the M_TEMP memory type.
741 */
742char *
743prop_array_externalize(prop_array_t pa)
744{
745	struct _prop_object_externalize_context *ctx;
746	char *cp;
747
748	ctx = _prop_object_externalize_context_alloc();
749	if (ctx == NULL)
750		return (NULL);
751
752	if (_prop_object_externalize_header(ctx) == false ||
753	    (*pa->pa_obj.po_type->pot_extern)(ctx, pa) == false ||
754	    _prop_object_externalize_footer(ctx) == false) {
755		/* We are responsible for releasing the buffer. */
756		_PROP_FREE(ctx->poec_buf, M_TEMP);
757		_prop_object_externalize_context_free(ctx);
758		return (NULL);
759	}
760
761	cp = ctx->poec_buf;
762	_prop_object_externalize_context_free(ctx);
763
764	return (cp);
765}
766
767/*
768 * _prop_array_internalize --
769 *	Parse an <array>...</array> and return the object created from the
770 *	external representation.
771 */
772static bool _prop_array_internalize_body(prop_stack_t, prop_object_t *,
773    struct _prop_object_internalize_context *);
774
775bool
776_prop_array_internalize(prop_stack_t stack, prop_object_t *obj,
777    struct _prop_object_internalize_context *ctx)
778{
779	/* We don't currently understand any attributes. */
780	if (ctx->poic_tagattr != NULL)
781		return (true);
782
783	*obj = prop_array_create();
784	/*
785	 * We are done if the create failed or no child elements exist.
786	 */
787	if (*obj == NULL || ctx->poic_is_empty_element)
788		return (true);
789
790	/*
791	 * Opening tag is found, now continue to the first element.
792	 */
793	return (_prop_array_internalize_body(stack, obj, ctx));
794}
795
796static bool
797_prop_array_internalize_continue(prop_stack_t stack,
798    prop_object_t *obj,
799    struct _prop_object_internalize_context *ctx,
800    void *data, prop_object_t child)
801{
802	prop_array_t array;
803
804	_PROP_ASSERT(data == NULL);
805
806	if (child == NULL)
807		goto bad; /* Element could not be parsed. */
808
809	array = *obj;
810
811	if (prop_array_add(array, child) == false) {
812		prop_object_release(child);
813		goto bad;
814	}
815	prop_object_release(child);
816
817	/*
818	 * Current element is processed and added, look for next.
819	 */
820	return (_prop_array_internalize_body(stack, obj, ctx));
821
822 bad:
823	prop_object_release(*obj);
824	*obj = NULL;
825	return (true);
826}
827
828static bool
829_prop_array_internalize_body(prop_stack_t stack, prop_object_t *obj,
830    struct _prop_object_internalize_context *ctx)
831{
832	prop_array_t array = *obj;
833
834	_PROP_ASSERT(array != NULL);
835
836	/* Fetch the next tag. */
837	if (_prop_object_internalize_find_tag(ctx, NULL,
838				_PROP_TAG_TYPE_EITHER) == false)
839		goto bad;
840
841	/* Check to see if this is the end of the array. */
842	if (_PROP_TAG_MATCH(ctx, "array") &&
843	    ctx->poic_tag_type == _PROP_TAG_TYPE_END) {
844		/* It is, so don't iterate any further. */
845		return (true);
846	}
847
848	if (_prop_stack_push(stack, array,
849			     _prop_array_internalize_continue, NULL, NULL))
850		return (false);
851
852 bad:
853	prop_object_release(array);
854	*obj = NULL;
855	return (true);
856}
857
858/*
859 * prop_array_internalize --
860 *	Create an array by parsing the XML-style representation.
861 */
862prop_array_t
863prop_array_internalize(const char *xml)
864{
865	return _prop_generic_internalize(xml, "array");
866}
867
868#if !defined(_KERNEL) && !defined(_STANDALONE)
869/*
870 * prop_array_externalize_to_file --
871 *	Externalize an array to the specified file.
872 */
873bool
874prop_array_externalize_to_file(prop_array_t array, const char *fname)
875{
876	char *xml;
877	bool rv;
878	int save_errno = 0;	/* XXXGCC -Wuninitialized [mips, ...] */
879
880	xml = prop_array_externalize(array);
881	if (xml == NULL)
882		return (false);
883	rv = _prop_object_externalize_write_file(fname, xml, strlen(xml));
884	if (rv == false)
885		save_errno = errno;
886	_PROP_FREE(xml, M_TEMP);
887	if (rv == false)
888		errno = save_errno;
889
890	return (rv);
891}
892
893/*
894 * prop_array_internalize_from_file --
895 *	Internalize an array from a file.
896 */
897prop_array_t
898prop_array_internalize_from_file(const char *fname)
899{
900	struct _prop_object_internalize_mapped_file *mf;
901	prop_array_t array;
902
903	mf = _prop_object_internalize_map_file(fname);
904	if (mf == NULL)
905		return (NULL);
906	array = prop_array_internalize(mf->poimf_xml);
907	_prop_object_internalize_unmap_file(mf);
908
909	return (array);
910}
911#endif /* _KERNEL && !_STANDALONE */
912