xref: /netbsd-src/common/lib/libprop/prop_number.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /*	$NetBSD: prop_number.c,v 1.19 2008/08/03 04:00:12 thorpej 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 const struct _prop_object_type _prop_object_type_number = {
78 	.pot_type	=	PROP_TYPE_NUMBER,
79 	.pot_free	=	_prop_number_free,
80 	.pot_extern	=	_prop_number_externalize,
81 	.pot_equals	=	_prop_number_equals,
82 };
83 
84 #define	prop_object_is_number(x)	\
85 	((x) != NULL && (x)->pn_obj.po_type == &_prop_object_type_number)
86 
87 /*
88  * Number objects are immutable, and we are likely to have many number
89  * objects that have the same value.  So, to save memory, we unique'ify
90  * numbers so we only have one copy of each.
91  */
92 
93 static int
94 _prop_number_compare_values(const struct _prop_number_value *pnv1,
95 			    const struct _prop_number_value *pnv2)
96 {
97 
98 	/* Signed numbers are sorted before unsigned numbers. */
99 
100 	if (pnv1->pnv_is_unsigned) {
101 		if (! pnv2->pnv_is_unsigned)
102 			return (1);
103 		if (pnv1->pnv_unsigned < pnv2->pnv_unsigned)
104 			return (-1);
105 		if (pnv1->pnv_unsigned > pnv2->pnv_unsigned)
106 			return (1);
107 		return (0);
108 	}
109 
110 	if (pnv2->pnv_is_unsigned)
111 		return (-1);
112 	if (pnv1->pnv_signed < pnv2->pnv_signed)
113 		return (-1);
114 	if (pnv1->pnv_signed > pnv2->pnv_signed)
115 		return (1);
116 	return (0);
117 }
118 
119 static int
120 _prop_number_rb_compare_nodes(const struct rb_node *n1,
121 			      const struct rb_node *n2)
122 {
123 	const prop_number_t pn1 = RBNODE_TO_PN(n1);
124 	const prop_number_t pn2 = RBNODE_TO_PN(n2);
125 
126 	return (_prop_number_compare_values(&pn1->pn_value, &pn2->pn_value));
127 }
128 
129 static int
130 _prop_number_rb_compare_key(const struct rb_node *n,
131 			    const void *v)
132 {
133 	const prop_number_t pn = RBNODE_TO_PN(n);
134 	const struct _prop_number_value *pnv = v;
135 
136 	return (_prop_number_compare_values(&pn->pn_value, pnv));
137 }
138 
139 static const struct rb_tree_ops _prop_number_rb_tree_ops = {
140 	.rbto_compare_nodes = _prop_number_rb_compare_nodes,
141 	.rbto_compare_key   = _prop_number_rb_compare_key,
142 };
143 
144 static struct rb_tree _prop_number_tree;
145 static bool _prop_number_tree_initialized;
146 
147 _PROP_MUTEX_DECL_STATIC(_prop_number_tree_mutex)
148 
149 /* ARGSUSED */
150 static _prop_object_free_rv_t
151 _prop_number_free(prop_stack_t stack, prop_object_t *obj)
152 {
153 	prop_number_t pn = *obj;
154 
155 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
156 	_prop_rb_tree_remove_node(&_prop_number_tree, &pn->pn_link);
157 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
158 
159 	_PROP_POOL_PUT(_prop_number_pool, pn);
160 
161 	return (_PROP_OBJECT_FREE_DONE);
162 }
163 
164 static bool
165 _prop_number_externalize(struct _prop_object_externalize_context *ctx,
166 			 void *v)
167 {
168 	prop_number_t pn = v;
169 	char tmpstr[32];
170 
171 	/*
172 	 * For unsigned numbers, we output in hex.  For signed numbers,
173 	 * we output in decimal.
174 	 */
175 	if (pn->pn_value.pnv_is_unsigned)
176 		sprintf(tmpstr, "0x%" PRIx64, pn->pn_value.pnv_unsigned);
177 	else
178 		sprintf(tmpstr, "%" PRIi64, pn->pn_value.pnv_signed);
179 
180 	if (_prop_object_externalize_start_tag(ctx, "integer") == false ||
181 	    _prop_object_externalize_append_cstring(ctx, tmpstr) == false ||
182 	    _prop_object_externalize_end_tag(ctx, "integer") == false)
183 		return (false);
184 
185 	return (true);
186 }
187 
188 /* ARGSUSED */
189 static _prop_object_equals_rv_t
190 _prop_number_equals(prop_object_t v1, prop_object_t v2,
191     void **stored_pointer1, void **stored_pointer2,
192     prop_object_t *next_obj1, prop_object_t *next_obj2)
193 {
194 	prop_number_t num1 = v1;
195 	prop_number_t num2 = v2;
196 
197 	/*
198 	 * There is only ever one copy of a number object at any given
199 	 * time, so we can reduce this to a simple pointer equality check
200 	 * in the common case.
201 	 */
202 	if (num1 == num2)
203 		return (_PROP_OBJECT_EQUALS_TRUE);
204 
205 	/*
206 	 * If the numbers are the same signed-ness, then we know they
207 	 * cannot be equal because they would have had pointer equality.
208 	 */
209 	if (num1->pn_value.pnv_is_unsigned == num2->pn_value.pnv_is_unsigned)
210 		return (_PROP_OBJECT_EQUALS_FALSE);
211 
212 	/*
213 	 * We now have one signed value and one unsigned value.  We can
214 	 * compare them iff:
215 	 *	- The unsigned value is not larger than the signed value
216 	 *	  can represent.
217 	 *	- The signed value is not smaller than the unsigned value
218 	 *	  can represent.
219 	 */
220 	if (num1->pn_value.pnv_is_unsigned) {
221 		/*
222 		 * num1 is unsigned and num2 is signed.
223 		 */
224 		if (num1->pn_value.pnv_unsigned > INT64_MAX)
225 			return (_PROP_OBJECT_EQUALS_FALSE);
226 		if (num2->pn_value.pnv_signed < 0)
227 			return (_PROP_OBJECT_EQUALS_FALSE);
228 	} else {
229 		/*
230 		 * num1 is signed and num2 is unsigned.
231 		 */
232 		if (num1->pn_value.pnv_signed < 0)
233 			return (_PROP_OBJECT_EQUALS_FALSE);
234 		if (num2->pn_value.pnv_unsigned > INT64_MAX)
235 			return (_PROP_OBJECT_EQUALS_FALSE);
236 	}
237 
238 	if (num1->pn_value.pnv_signed == num2->pn_value.pnv_signed)
239 		return _PROP_OBJECT_EQUALS_TRUE;
240 	else
241 		return _PROP_OBJECT_EQUALS_FALSE;
242 }
243 
244 static prop_number_t
245 _prop_number_alloc(const struct _prop_number_value *pnv)
246 {
247 	prop_number_t opn, pn;
248 	struct rb_node *n;
249 	bool rv;
250 
251 	/*
252 	 * Check to see if this already exists in the tree.  If it does,
253 	 * we just retain it and return it.
254 	 */
255 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
256 	if (! _prop_number_tree_initialized) {
257 		_prop_rb_tree_init(&_prop_number_tree,
258 				   &_prop_number_rb_tree_ops);
259 		_prop_number_tree_initialized = true;
260 	} else {
261 		n = _prop_rb_tree_find(&_prop_number_tree, pnv);
262 		if (n != NULL) {
263 			opn = RBNODE_TO_PN(n);
264 			prop_object_retain(opn);
265 			_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
266 			return (opn);
267 		}
268 	}
269 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
270 
271 	/*
272 	 * Not in the tree.  Create it now.
273 	 */
274 
275 	pn = _PROP_POOL_GET(_prop_number_pool);
276 	if (pn == NULL)
277 		return (NULL);
278 
279 	_prop_object_init(&pn->pn_obj, &_prop_object_type_number);
280 
281 	pn->pn_value = *pnv;
282 
283 	/*
284 	 * We dropped the mutex when we allocated the new object, so
285 	 * we have to check again if it is in the tree.
286 	 */
287 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
288 	n = _prop_rb_tree_find(&_prop_number_tree, pnv);
289 	if (n != NULL) {
290 		opn = RBNODE_TO_PN(n);
291 		prop_object_retain(opn);
292 		_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
293 		_PROP_POOL_PUT(_prop_number_pool, pn);
294 		return (opn);
295 	}
296 	rv = _prop_rb_tree_insert_node(&_prop_number_tree, &pn->pn_link);
297 	_PROP_ASSERT(rv == true);
298 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
299 	return (pn);
300 }
301 
302 /*
303  * prop_number_create_integer --
304  *	Create a prop_number_t and initialize it with the
305  *	provided integer value.
306  */
307 prop_number_t
308 prop_number_create_integer(int64_t val)
309 {
310 	struct _prop_number_value pnv;
311 
312 	memset(&pnv, 0, sizeof(pnv));
313 	pnv.pnv_signed = val;
314 	pnv.pnv_is_unsigned = false;
315 
316 	return (_prop_number_alloc(&pnv));
317 }
318 
319 /*
320  * prop_number_create_unsigned_integer --
321  *	Create a prop_number_t and initialize it with the
322  *	provided unsigned integer value.
323  */
324 prop_number_t
325 prop_number_create_unsigned_integer(uint64_t val)
326 {
327 	struct _prop_number_value pnv;
328 
329 	memset(&pnv, 0, sizeof(pnv));
330 	pnv.pnv_unsigned = val;
331 	pnv.pnv_is_unsigned = true;
332 
333 	return (_prop_number_alloc(&pnv));
334 }
335 
336 /*
337  * prop_number_copy --
338  *	Copy a prop_number_t.
339  */
340 prop_number_t
341 prop_number_copy(prop_number_t opn)
342 {
343 
344 	if (! prop_object_is_number(opn))
345 		return (NULL);
346 
347 	/*
348 	 * Because we only ever allocate one object for any given
349 	 * value, this can be reduced to a simple retain operation.
350 	 */
351 	prop_object_retain(opn);
352 	return (opn);
353 }
354 
355 /*
356  * prop_number_unsigned --
357  *	Returns true if the prop_number_t has an unsigned value.
358  */
359 bool
360 prop_number_unsigned(prop_number_t pn)
361 {
362 
363 	return (pn->pn_value.pnv_is_unsigned);
364 }
365 
366 /*
367  * prop_number_size --
368  *	Return the size, in bits, required to hold the value of
369  *	the specified number.
370  */
371 int
372 prop_number_size(prop_number_t pn)
373 {
374 	struct _prop_number_value *pnv;
375 
376 	if (! prop_object_is_number(pn))
377 		return (0);
378 
379 	pnv = &pn->pn_value;
380 
381 	if (pnv->pnv_is_unsigned) {
382 		if (pnv->pnv_unsigned > UINT32_MAX)
383 			return (64);
384 		if (pnv->pnv_unsigned > UINT16_MAX)
385 			return (32);
386 		if (pnv->pnv_unsigned > UINT8_MAX)
387 			return (16);
388 		return (8);
389 	}
390 
391 	if (pnv->pnv_signed > INT32_MAX || pnv->pnv_signed < INT32_MIN)
392 	    	return (64);
393 	if (pnv->pnv_signed > INT16_MAX || pnv->pnv_signed < INT16_MIN)
394 		return (32);
395 	if (pnv->pnv_signed > INT8_MAX  || pnv->pnv_signed < INT8_MIN)
396 		return (16);
397 	return (8);
398 }
399 
400 /*
401  * prop_number_integer_value --
402  *	Get the integer value of a prop_number_t.
403  */
404 int64_t
405 prop_number_integer_value(prop_number_t pn)
406 {
407 
408 	/*
409 	 * XXX Impossible to distinguish between "not a prop_number_t"
410 	 * XXX and "prop_number_t has a value of 0".
411 	 */
412 	if (! prop_object_is_number(pn))
413 		return (0);
414 
415 	return (pn->pn_value.pnv_signed);
416 }
417 
418 /*
419  * prop_number_unsigned_integer_value --
420  *	Get the unsigned integer value of a prop_number_t.
421  */
422 uint64_t
423 prop_number_unsigned_integer_value(prop_number_t pn)
424 {
425 
426 	/*
427 	 * XXX Impossible to distinguish between "not a prop_number_t"
428 	 * XXX and "prop_number_t has a value of 0".
429 	 */
430 	if (! prop_object_is_number(pn))
431 		return (0);
432 
433 	return (pn->pn_value.pnv_unsigned);
434 }
435 
436 /*
437  * prop_number_equals --
438  *	Return true if two numbers are equivalent.
439  */
440 bool
441 prop_number_equals(prop_number_t num1, prop_number_t num2)
442 {
443 	if (!prop_object_is_number(num1) || !prop_object_is_number(num2))
444 		return (false);
445 
446 	return (prop_object_equals(num1, num2));
447 }
448 
449 /*
450  * prop_number_equals_integer --
451  *	Return true if the number is equivalent to the specified integer.
452  */
453 bool
454 prop_number_equals_integer(prop_number_t pn, int64_t val)
455 {
456 
457 	if (! prop_object_is_number(pn))
458 		return (false);
459 
460 	if (pn->pn_value.pnv_is_unsigned &&
461 	    (pn->pn_value.pnv_unsigned > INT64_MAX || val < 0))
462 		return (false);
463 
464 	return (pn->pn_value.pnv_signed == val);
465 }
466 
467 /*
468  * prop_number_equals_unsigned_integer --
469  *	Return true if the number is equivalent to the specified
470  *	unsigned integer.
471  */
472 bool
473 prop_number_equals_unsigned_integer(prop_number_t pn, uint64_t val)
474 {
475 
476 	if (! prop_object_is_number(pn))
477 		return (false);
478 
479 	if (! pn->pn_value.pnv_is_unsigned &&
480 	    (pn->pn_value.pnv_signed < 0 || val > INT64_MAX))
481 		return (false);
482 
483 	return (pn->pn_value.pnv_unsigned == val);
484 }
485 
486 static bool
487 _prop_number_internalize_unsigned(struct _prop_object_internalize_context *ctx,
488 				  struct _prop_number_value *pnv)
489 {
490 	char *cp;
491 
492 	_PROP_ASSERT(/*CONSTCOND*/sizeof(unsigned long long) ==
493 		     sizeof(uint64_t));
494 
495 #ifndef _KERNEL
496 	errno = 0;
497 #endif
498 	pnv->pnv_unsigned = (uint64_t) strtoull(ctx->poic_cp, &cp, 0);
499 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
500 	if (pnv->pnv_unsigned == UINT64_MAX && errno == ERANGE)
501 		return (false);
502 #endif
503 	pnv->pnv_is_unsigned = true;
504 	ctx->poic_cp = cp;
505 
506 	return (true);
507 }
508 
509 static bool
510 _prop_number_internalize_signed(struct _prop_object_internalize_context *ctx,
511 				struct _prop_number_value *pnv)
512 {
513 	char *cp;
514 
515 	_PROP_ASSERT(/*CONSTCOND*/sizeof(long long) == sizeof(int64_t));
516 
517 #ifndef _KERNEL
518 	errno = 0;
519 #endif
520 	pnv->pnv_signed = (int64_t) strtoll(ctx->poic_cp, &cp, 0);
521 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
522 	if ((pnv->pnv_signed == INT64_MAX || pnv->pnv_signed == INT64_MIN) &&
523 	    errno == ERANGE)
524 	    	return (false);
525 #endif
526 	pnv->pnv_is_unsigned = false;
527 	ctx->poic_cp = cp;
528 
529 	return (true);
530 }
531 
532 /*
533  * _prop_number_internalize --
534  *	Parse a <number>...</number> and return the object created from
535  *	the external representation.
536  */
537 /* ARGSUSED */
538 bool
539 _prop_number_internalize(prop_stack_t stack, prop_object_t *obj,
540     struct _prop_object_internalize_context *ctx)
541 {
542 	struct _prop_number_value pnv;
543 
544 	memset(&pnv, 0, sizeof(pnv));
545 
546 	/* No attributes, no empty elements. */
547 	if (ctx->poic_tagattr != NULL || ctx->poic_is_empty_element)
548 		return (true);
549 
550 	/*
551 	 * If the first character is '-', then we treat as signed.
552 	 * If the first two characters are "0x" (i.e. the number is
553 	 * in hex), then we treat as unsigned.  Otherwise, we try
554 	 * signed first, and if that fails (presumably due to ERANGE),
555 	 * then we switch to unsigned.
556 	 */
557 	if (ctx->poic_cp[0] == '-') {
558 		if (_prop_number_internalize_signed(ctx, &pnv) == false)
559 			return (true);
560 	} else if (ctx->poic_cp[0] == '0' && ctx->poic_cp[1] == 'x') {
561 		if (_prop_number_internalize_unsigned(ctx, &pnv) == false)
562 			return (true);
563 	} else {
564 		if (_prop_number_internalize_signed(ctx, &pnv) == false &&
565 		    _prop_number_internalize_unsigned(ctx, &pnv) == false)
566 		    	return (true);
567 	}
568 
569 	if (_prop_object_internalize_find_tag(ctx, "integer",
570 					      _PROP_TAG_TYPE_END) == false)
571 		return (true);
572 
573 	*obj = _prop_number_alloc(&pnv);
574 	return (true);
575 }
576