xref: /netbsd-src/common/lib/libprop/prop_number.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: prop_number.c,v 1.22 2009/03/15 22:29:11 cegger Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006 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_number.h>
33 #include "prop_object_impl.h"
34 #include "prop_rb_impl.h"
35 
36 #if defined(_KERNEL)
37 #include <sys/systm.h>
38 #elif defined(_STANDALONE)
39 #include <sys/param.h>
40 #include <lib/libkern/libkern.h>
41 #else
42 #include <errno.h>
43 #include <stdlib.h>
44 #endif
45 
46 struct _prop_number {
47 	struct _prop_object	pn_obj;
48 	struct rb_node		pn_link;
49 	struct _prop_number_value {
50 		union {
51 			int64_t  pnu_signed;
52 			uint64_t pnu_unsigned;
53 		} pnv_un;
54 #define	pnv_signed	pnv_un.pnu_signed
55 #define	pnv_unsigned	pnv_un.pnu_unsigned
56 		unsigned int	pnv_is_unsigned	:1,
57 						:31;
58 	} pn_value;
59 };
60 
61 #define	RBNODE_TO_PN(n)							\
62 	((struct _prop_number *)					\
63 	 ((uintptr_t)n - offsetof(struct _prop_number, pn_link)))
64 
65 _PROP_POOL_INIT(_prop_number_pool, sizeof(struct _prop_number), "propnmbr")
66 
67 static _prop_object_free_rv_t
68 		_prop_number_free(prop_stack_t, prop_object_t *);
69 static bool	_prop_number_externalize(
70 				struct _prop_object_externalize_context *,
71 				void *);
72 static _prop_object_equals_rv_t
73 		_prop_number_equals(prop_object_t, prop_object_t,
74 				    void **, void **,
75 				    prop_object_t *, prop_object_t *);
76 
77 static void _prop_number_lock(void);
78 static void _prop_number_unlock(void);
79 
80 static const struct _prop_object_type _prop_object_type_number = {
81 	.pot_type	=	PROP_TYPE_NUMBER,
82 	.pot_free	=	_prop_number_free,
83 	.pot_extern	=	_prop_number_externalize,
84 	.pot_equals	=	_prop_number_equals,
85 	.pot_lock       =       _prop_number_lock,
86 	.pot_unlock     =    	_prop_number_unlock,
87 };
88 
89 #define	prop_object_is_number(x)	\
90 	((x) != NULL && (x)->pn_obj.po_type == &_prop_object_type_number)
91 
92 /*
93  * Number objects are immutable, and we are likely to have many number
94  * objects that have the same value.  So, to save memory, we unique'ify
95  * numbers so we only have one copy of each.
96  */
97 
98 static int
99 _prop_number_compare_values(const struct _prop_number_value *pnv1,
100 			    const struct _prop_number_value *pnv2)
101 {
102 
103 	/* Signed numbers are sorted before unsigned numbers. */
104 
105 	if (pnv1->pnv_is_unsigned) {
106 		if (! pnv2->pnv_is_unsigned)
107 			return (1);
108 		if (pnv1->pnv_unsigned < pnv2->pnv_unsigned)
109 			return (-1);
110 		if (pnv1->pnv_unsigned > pnv2->pnv_unsigned)
111 			return (1);
112 		return (0);
113 	}
114 
115 	if (pnv2->pnv_is_unsigned)
116 		return (-1);
117 	if (pnv1->pnv_signed < pnv2->pnv_signed)
118 		return (-1);
119 	if (pnv1->pnv_signed > pnv2->pnv_signed)
120 		return (1);
121 	return (0);
122 }
123 
124 static int
125 _prop_number_rb_compare_nodes(const struct rb_node *n1,
126 			      const struct rb_node *n2)
127 {
128 	const prop_number_t pn1 = RBNODE_TO_PN(n1);
129 	const prop_number_t pn2 = RBNODE_TO_PN(n2);
130 
131 	return (_prop_number_compare_values(&pn1->pn_value, &pn2->pn_value));
132 }
133 
134 static int
135 _prop_number_rb_compare_key(const struct rb_node *n,
136 			    const void *v)
137 {
138 	const prop_number_t pn = RBNODE_TO_PN(n);
139 	const struct _prop_number_value *pnv = v;
140 
141 	return (_prop_number_compare_values(&pn->pn_value, pnv));
142 }
143 
144 static const struct rb_tree_ops _prop_number_rb_tree_ops = {
145 	.rbto_compare_nodes = _prop_number_rb_compare_nodes,
146 	.rbto_compare_key   = _prop_number_rb_compare_key,
147 };
148 
149 static struct rb_tree _prop_number_tree;
150 _PROP_MUTEX_DECL_STATIC(_prop_number_tree_mutex)
151 
152 /* ARGSUSED */
153 static _prop_object_free_rv_t
154 _prop_number_free(prop_stack_t stack, prop_object_t *obj)
155 {
156 	prop_number_t pn = *obj;
157 
158 	_prop_rb_tree_remove_node(&_prop_number_tree, &pn->pn_link);
159 
160 	_PROP_POOL_PUT(_prop_number_pool, pn);
161 
162 	return (_PROP_OBJECT_FREE_DONE);
163 }
164 
165 _PROP_ONCE_DECL(_prop_number_init_once)
166 
167 static int
168 _prop_number_init(void)
169 {
170 
171 	_PROP_MUTEX_INIT(_prop_number_tree_mutex);
172 	_prop_rb_tree_init(&_prop_number_tree,
173 	    &_prop_number_rb_tree_ops);
174 	return 0;
175 }
176 
177 static void
178 _prop_number_lock(void)
179 {
180 	/* XXX: init necessary? */
181 	_PROP_ONCE_RUN(_prop_number_init_once, _prop_number_init);
182 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
183 }
184 
185 static void
186 _prop_number_unlock(void)
187 {
188 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
189 }
190 
191 static bool
192 _prop_number_externalize(struct _prop_object_externalize_context *ctx,
193 			 void *v)
194 {
195 	prop_number_t pn = v;
196 	char tmpstr[32];
197 
198 	/*
199 	 * For unsigned numbers, we output in hex.  For signed numbers,
200 	 * we output in decimal.
201 	 */
202 	if (pn->pn_value.pnv_is_unsigned)
203 		sprintf(tmpstr, "0x%" PRIx64, pn->pn_value.pnv_unsigned);
204 	else
205 		sprintf(tmpstr, "%" PRIi64, pn->pn_value.pnv_signed);
206 
207 	if (_prop_object_externalize_start_tag(ctx, "integer") == false ||
208 	    _prop_object_externalize_append_cstring(ctx, tmpstr) == false ||
209 	    _prop_object_externalize_end_tag(ctx, "integer") == false)
210 		return (false);
211 
212 	return (true);
213 }
214 
215 /* ARGSUSED */
216 static _prop_object_equals_rv_t
217 _prop_number_equals(prop_object_t v1, prop_object_t v2,
218     void **stored_pointer1, void **stored_pointer2,
219     prop_object_t *next_obj1, prop_object_t *next_obj2)
220 {
221 	prop_number_t num1 = v1;
222 	prop_number_t num2 = v2;
223 
224 	/*
225 	 * There is only ever one copy of a number object at any given
226 	 * time, so we can reduce this to a simple pointer equality check
227 	 * in the common case.
228 	 */
229 	if (num1 == num2)
230 		return (_PROP_OBJECT_EQUALS_TRUE);
231 
232 	/*
233 	 * If the numbers are the same signed-ness, then we know they
234 	 * cannot be equal because they would have had pointer equality.
235 	 */
236 	if (num1->pn_value.pnv_is_unsigned == num2->pn_value.pnv_is_unsigned)
237 		return (_PROP_OBJECT_EQUALS_FALSE);
238 
239 	/*
240 	 * We now have one signed value and one unsigned value.  We can
241 	 * compare them iff:
242 	 *	- The unsigned value is not larger than the signed value
243 	 *	  can represent.
244 	 *	- The signed value is not smaller than the unsigned value
245 	 *	  can represent.
246 	 */
247 	if (num1->pn_value.pnv_is_unsigned) {
248 		/*
249 		 * num1 is unsigned and num2 is signed.
250 		 */
251 		if (num1->pn_value.pnv_unsigned > INT64_MAX)
252 			return (_PROP_OBJECT_EQUALS_FALSE);
253 		if (num2->pn_value.pnv_signed < 0)
254 			return (_PROP_OBJECT_EQUALS_FALSE);
255 	} else {
256 		/*
257 		 * num1 is signed and num2 is unsigned.
258 		 */
259 		if (num1->pn_value.pnv_signed < 0)
260 			return (_PROP_OBJECT_EQUALS_FALSE);
261 		if (num2->pn_value.pnv_unsigned > INT64_MAX)
262 			return (_PROP_OBJECT_EQUALS_FALSE);
263 	}
264 
265 	if (num1->pn_value.pnv_signed == num2->pn_value.pnv_signed)
266 		return _PROP_OBJECT_EQUALS_TRUE;
267 	else
268 		return _PROP_OBJECT_EQUALS_FALSE;
269 }
270 
271 static prop_number_t
272 _prop_number_alloc(const struct _prop_number_value *pnv)
273 {
274 	prop_number_t opn, pn;
275 	struct rb_node *n;
276 	bool rv;
277 
278 	_PROP_ONCE_RUN(_prop_number_init_once, _prop_number_init);
279 
280 	/*
281 	 * Check to see if this already exists in the tree.  If it does,
282 	 * we just retain it and return it.
283 	 */
284 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
285 	n = _prop_rb_tree_find(&_prop_number_tree, pnv);
286 	if (n != NULL) {
287 		opn = RBNODE_TO_PN(n);
288 		prop_object_retain(opn);
289 		_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
290 		return (opn);
291 	}
292 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
293 
294 	/*
295 	 * Not in the tree.  Create it now.
296 	 */
297 
298 	pn = _PROP_POOL_GET(_prop_number_pool);
299 	if (pn == NULL)
300 		return (NULL);
301 
302 	_prop_object_init(&pn->pn_obj, &_prop_object_type_number);
303 
304 	pn->pn_value = *pnv;
305 
306 	/*
307 	 * We dropped the mutex when we allocated the new object, so
308 	 * we have to check again if it is in the tree.
309 	 */
310 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
311 	n = _prop_rb_tree_find(&_prop_number_tree, pnv);
312 	if (n != NULL) {
313 		opn = RBNODE_TO_PN(n);
314 		prop_object_retain(opn);
315 		_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
316 		_PROP_POOL_PUT(_prop_number_pool, pn);
317 		return (opn);
318 	}
319 	rv = _prop_rb_tree_insert_node(&_prop_number_tree, &pn->pn_link);
320 	_PROP_ASSERT(rv == true);
321 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
322 	return (pn);
323 }
324 
325 /*
326  * prop_number_create_integer --
327  *	Create a prop_number_t and initialize it with the
328  *	provided integer value.
329  */
330 prop_number_t
331 prop_number_create_integer(int64_t val)
332 {
333 	struct _prop_number_value pnv;
334 
335 	memset(&pnv, 0, sizeof(pnv));
336 	pnv.pnv_signed = val;
337 	pnv.pnv_is_unsigned = false;
338 
339 	return (_prop_number_alloc(&pnv));
340 }
341 
342 /*
343  * prop_number_create_unsigned_integer --
344  *	Create a prop_number_t and initialize it with the
345  *	provided unsigned integer value.
346  */
347 prop_number_t
348 prop_number_create_unsigned_integer(uint64_t val)
349 {
350 	struct _prop_number_value pnv;
351 
352 	memset(&pnv, 0, sizeof(pnv));
353 	pnv.pnv_unsigned = val;
354 	pnv.pnv_is_unsigned = true;
355 
356 	return (_prop_number_alloc(&pnv));
357 }
358 
359 /*
360  * prop_number_copy --
361  *	Copy a prop_number_t.
362  */
363 prop_number_t
364 prop_number_copy(prop_number_t opn)
365 {
366 
367 	if (! prop_object_is_number(opn))
368 		return (NULL);
369 
370 	/*
371 	 * Because we only ever allocate one object for any given
372 	 * value, this can be reduced to a simple retain operation.
373 	 */
374 	prop_object_retain(opn);
375 	return (opn);
376 }
377 
378 /*
379  * prop_number_unsigned --
380  *	Returns true if the prop_number_t has an unsigned value.
381  */
382 bool
383 prop_number_unsigned(prop_number_t pn)
384 {
385 
386 	return (pn->pn_value.pnv_is_unsigned);
387 }
388 
389 /*
390  * prop_number_size --
391  *	Return the size, in bits, required to hold the value of
392  *	the specified number.
393  */
394 int
395 prop_number_size(prop_number_t pn)
396 {
397 	struct _prop_number_value *pnv;
398 
399 	if (! prop_object_is_number(pn))
400 		return (0);
401 
402 	pnv = &pn->pn_value;
403 
404 	if (pnv->pnv_is_unsigned) {
405 		if (pnv->pnv_unsigned > UINT32_MAX)
406 			return (64);
407 		if (pnv->pnv_unsigned > UINT16_MAX)
408 			return (32);
409 		if (pnv->pnv_unsigned > UINT8_MAX)
410 			return (16);
411 		return (8);
412 	}
413 
414 	if (pnv->pnv_signed > INT32_MAX || pnv->pnv_signed < INT32_MIN)
415 	    	return (64);
416 	if (pnv->pnv_signed > INT16_MAX || pnv->pnv_signed < INT16_MIN)
417 		return (32);
418 	if (pnv->pnv_signed > INT8_MAX  || pnv->pnv_signed < INT8_MIN)
419 		return (16);
420 	return (8);
421 }
422 
423 /*
424  * prop_number_integer_value --
425  *	Get the integer value of a prop_number_t.
426  */
427 int64_t
428 prop_number_integer_value(prop_number_t pn)
429 {
430 
431 	/*
432 	 * XXX Impossible to distinguish between "not a prop_number_t"
433 	 * XXX and "prop_number_t has a value of 0".
434 	 */
435 	if (! prop_object_is_number(pn))
436 		return (0);
437 
438 	return (pn->pn_value.pnv_signed);
439 }
440 
441 /*
442  * prop_number_unsigned_integer_value --
443  *	Get the unsigned integer value of a prop_number_t.
444  */
445 uint64_t
446 prop_number_unsigned_integer_value(prop_number_t pn)
447 {
448 
449 	/*
450 	 * XXX Impossible to distinguish between "not a prop_number_t"
451 	 * XXX and "prop_number_t has a value of 0".
452 	 */
453 	if (! prop_object_is_number(pn))
454 		return (0);
455 
456 	return (pn->pn_value.pnv_unsigned);
457 }
458 
459 /*
460  * prop_number_equals --
461  *	Return true if two numbers are equivalent.
462  */
463 bool
464 prop_number_equals(prop_number_t num1, prop_number_t num2)
465 {
466 	if (!prop_object_is_number(num1) || !prop_object_is_number(num2))
467 		return (false);
468 
469 	return (prop_object_equals(num1, num2));
470 }
471 
472 /*
473  * prop_number_equals_integer --
474  *	Return true if the number is equivalent to the specified integer.
475  */
476 bool
477 prop_number_equals_integer(prop_number_t pn, int64_t val)
478 {
479 
480 	if (! prop_object_is_number(pn))
481 		return (false);
482 
483 	if (pn->pn_value.pnv_is_unsigned &&
484 	    (pn->pn_value.pnv_unsigned > INT64_MAX || val < 0))
485 		return (false);
486 
487 	return (pn->pn_value.pnv_signed == val);
488 }
489 
490 /*
491  * prop_number_equals_unsigned_integer --
492  *	Return true if the number is equivalent to the specified
493  *	unsigned integer.
494  */
495 bool
496 prop_number_equals_unsigned_integer(prop_number_t pn, uint64_t val)
497 {
498 
499 	if (! prop_object_is_number(pn))
500 		return (false);
501 
502 	if (! pn->pn_value.pnv_is_unsigned &&
503 	    (pn->pn_value.pnv_signed < 0 || val > INT64_MAX))
504 		return (false);
505 
506 	return (pn->pn_value.pnv_unsigned == val);
507 }
508 
509 static bool
510 _prop_number_internalize_unsigned(struct _prop_object_internalize_context *ctx,
511 				  struct _prop_number_value *pnv)
512 {
513 	char *cp;
514 
515 	_PROP_ASSERT(/*CONSTCOND*/sizeof(unsigned long long) ==
516 		     sizeof(uint64_t));
517 
518 #ifndef _KERNEL
519 	errno = 0;
520 #endif
521 	pnv->pnv_unsigned = (uint64_t) strtoull(ctx->poic_cp, &cp, 0);
522 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
523 	if (pnv->pnv_unsigned == UINT64_MAX && errno == ERANGE)
524 		return (false);
525 #endif
526 	pnv->pnv_is_unsigned = true;
527 	ctx->poic_cp = cp;
528 
529 	return (true);
530 }
531 
532 static bool
533 _prop_number_internalize_signed(struct _prop_object_internalize_context *ctx,
534 				struct _prop_number_value *pnv)
535 {
536 	char *cp;
537 
538 	_PROP_ASSERT(/*CONSTCOND*/sizeof(long long) == sizeof(int64_t));
539 
540 #ifndef _KERNEL
541 	errno = 0;
542 #endif
543 	pnv->pnv_signed = (int64_t) strtoll(ctx->poic_cp, &cp, 0);
544 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
545 	if ((pnv->pnv_signed == INT64_MAX || pnv->pnv_signed == INT64_MIN) &&
546 	    errno == ERANGE)
547 	    	return (false);
548 #endif
549 	pnv->pnv_is_unsigned = false;
550 	ctx->poic_cp = cp;
551 
552 	return (true);
553 }
554 
555 /*
556  * _prop_number_internalize --
557  *	Parse a <number>...</number> and return the object created from
558  *	the external representation.
559  */
560 /* ARGSUSED */
561 bool
562 _prop_number_internalize(prop_stack_t stack, prop_object_t *obj,
563     struct _prop_object_internalize_context *ctx)
564 {
565 	struct _prop_number_value pnv;
566 
567 	memset(&pnv, 0, sizeof(pnv));
568 
569 	/* No attributes, no empty elements. */
570 	if (ctx->poic_tagattr != NULL || ctx->poic_is_empty_element)
571 		return (true);
572 
573 	/*
574 	 * If the first character is '-', then we treat as signed.
575 	 * If the first two characters are "0x" (i.e. the number is
576 	 * in hex), then we treat as unsigned.  Otherwise, we try
577 	 * signed first, and if that fails (presumably due to ERANGE),
578 	 * then we switch to unsigned.
579 	 */
580 	if (ctx->poic_cp[0] == '-') {
581 		if (_prop_number_internalize_signed(ctx, &pnv) == false)
582 			return (true);
583 	} else if (ctx->poic_cp[0] == '0' && ctx->poic_cp[1] == 'x') {
584 		if (_prop_number_internalize_unsigned(ctx, &pnv) == false)
585 			return (true);
586 	} else {
587 		if (_prop_number_internalize_signed(ctx, &pnv) == false &&
588 		    _prop_number_internalize_unsigned(ctx, &pnv) == false)
589 		    	return (true);
590 	}
591 
592 	if (_prop_object_internalize_find_tag(ctx, "integer",
593 					      _PROP_TAG_TYPE_END) == false)
594 		return (true);
595 
596 	*obj = _prop_number_alloc(&pnv);
597 	return (true);
598 }
599