xref: /minix/common/lib/libprop/prop_number.c (revision ebfedea0)
1 /*	$NetBSD: prop_number.c,v 1.25 2013/10/18 18:26:20 martin 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 _PROP_POOL_INIT(_prop_number_pool, sizeof(struct _prop_number), "propnmbr")
62 
63 static _prop_object_free_rv_t
64 		_prop_number_free(prop_stack_t, prop_object_t *);
65 static bool	_prop_number_externalize(
66 				struct _prop_object_externalize_context *,
67 				void *);
68 static _prop_object_equals_rv_t
69 		_prop_number_equals(prop_object_t, prop_object_t,
70 				    void **, void **,
71 				    prop_object_t *, prop_object_t *);
72 
73 static void _prop_number_lock(void);
74 static void _prop_number_unlock(void);
75 
76 static const struct _prop_object_type _prop_object_type_number = {
77 	.pot_type	=	PROP_TYPE_NUMBER,
78 	.pot_free	=	_prop_number_free,
79 	.pot_extern	=	_prop_number_externalize,
80 	.pot_equals	=	_prop_number_equals,
81 	.pot_lock       =       _prop_number_lock,
82 	.pot_unlock     =    	_prop_number_unlock,
83 };
84 
85 #define	prop_object_is_number(x)	\
86 	((x) != NULL && (x)->pn_obj.po_type == &_prop_object_type_number)
87 
88 /*
89  * Number objects are immutable, and we are likely to have many number
90  * objects that have the same value.  So, to save memory, we unique'ify
91  * numbers so we only have one copy of each.
92  */
93 
94 static int
95 _prop_number_compare_values(const struct _prop_number_value *pnv1,
96 			    const struct _prop_number_value *pnv2)
97 {
98 
99 	/* Signed numbers are sorted before unsigned numbers. */
100 
101 	if (pnv1->pnv_is_unsigned) {
102 		if (! pnv2->pnv_is_unsigned)
103 			return (1);
104 		if (pnv1->pnv_unsigned < pnv2->pnv_unsigned)
105 			return (-1);
106 		if (pnv1->pnv_unsigned > pnv2->pnv_unsigned)
107 			return (1);
108 		return (0);
109 	}
110 
111 	if (pnv2->pnv_is_unsigned)
112 		return (-1);
113 	if (pnv1->pnv_signed < pnv2->pnv_signed)
114 		return (-1);
115 	if (pnv1->pnv_signed > pnv2->pnv_signed)
116 		return (1);
117 	return (0);
118 }
119 
120 static int
121 /*ARGSUSED*/
122 _prop_number_rb_compare_nodes(void *ctx _PROP_ARG_UNUSED,
123 			      const void *n1, const void *n2)
124 {
125 	const struct _prop_number *pn1 = n1;
126 	const struct _prop_number *pn2 = n2;
127 
128 	return _prop_number_compare_values(&pn1->pn_value, &pn2->pn_value);
129 }
130 
131 static int
132 /*ARGSUSED*/
133 _prop_number_rb_compare_key(void *ctx _PROP_ARG_UNUSED,
134 			    const void *n, const void *v)
135 {
136 	const struct _prop_number *pn = n;
137 	const struct _prop_number_value *pnv = v;
138 
139 	return _prop_number_compare_values(&pn->pn_value, pnv);
140 }
141 
142 static const rb_tree_ops_t _prop_number_rb_tree_ops = {
143 	.rbto_compare_nodes = _prop_number_rb_compare_nodes,
144 	.rbto_compare_key = _prop_number_rb_compare_key,
145 	.rbto_node_offset = offsetof(struct _prop_number, pn_link),
146 	.rbto_context = NULL
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);
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, &_prop_number_rb_tree_ops);
173 	return 0;
174 }
175 
176 static void
177 _prop_number_lock(void)
178 {
179 	/* XXX: init necessary? */
180 	_PROP_ONCE_RUN(_prop_number_init_once, _prop_number_init);
181 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
182 }
183 
184 static void
185 _prop_number_unlock(void)
186 {
187 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
188 }
189 
190 static bool
191 _prop_number_externalize(struct _prop_object_externalize_context *ctx,
192 			 void *v)
193 {
194 	prop_number_t pn = v;
195 	char tmpstr[32];
196 
197 	/*
198 	 * For unsigned numbers, we output in hex.  For signed numbers,
199 	 * we output in decimal.
200 	 */
201 	if (pn->pn_value.pnv_is_unsigned)
202 		sprintf(tmpstr, "0x%" PRIx64, pn->pn_value.pnv_unsigned);
203 	else
204 		sprintf(tmpstr, "%" PRIi64, pn->pn_value.pnv_signed);
205 
206 	if (_prop_object_externalize_start_tag(ctx, "integer") == false ||
207 	    _prop_object_externalize_append_cstring(ctx, tmpstr) == false ||
208 	    _prop_object_externalize_end_tag(ctx, "integer") == false)
209 		return (false);
210 
211 	return (true);
212 }
213 
214 /* ARGSUSED */
215 static _prop_object_equals_rv_t
216 _prop_number_equals(prop_object_t v1, prop_object_t v2,
217     void **stored_pointer1, void **stored_pointer2,
218     prop_object_t *next_obj1, prop_object_t *next_obj2)
219 {
220 	prop_number_t num1 = v1;
221 	prop_number_t num2 = v2;
222 
223 	/*
224 	 * There is only ever one copy of a number object at any given
225 	 * time, so we can reduce this to a simple pointer equality check
226 	 * in the common case.
227 	 */
228 	if (num1 == num2)
229 		return (_PROP_OBJECT_EQUALS_TRUE);
230 
231 	/*
232 	 * If the numbers are the same signed-ness, then we know they
233 	 * cannot be equal because they would have had pointer equality.
234 	 */
235 	if (num1->pn_value.pnv_is_unsigned == num2->pn_value.pnv_is_unsigned)
236 		return (_PROP_OBJECT_EQUALS_FALSE);
237 
238 	/*
239 	 * We now have one signed value and one unsigned value.  We can
240 	 * compare them iff:
241 	 *	- The unsigned value is not larger than the signed value
242 	 *	  can represent.
243 	 *	- The signed value is not smaller than the unsigned value
244 	 *	  can represent.
245 	 */
246 	if (num1->pn_value.pnv_is_unsigned) {
247 		/*
248 		 * num1 is unsigned and num2 is signed.
249 		 */
250 		if (num1->pn_value.pnv_unsigned > INT64_MAX)
251 			return (_PROP_OBJECT_EQUALS_FALSE);
252 		if (num2->pn_value.pnv_signed < 0)
253 			return (_PROP_OBJECT_EQUALS_FALSE);
254 	} else {
255 		/*
256 		 * num1 is signed and num2 is unsigned.
257 		 */
258 		if (num1->pn_value.pnv_signed < 0)
259 			return (_PROP_OBJECT_EQUALS_FALSE);
260 		if (num2->pn_value.pnv_unsigned > INT64_MAX)
261 			return (_PROP_OBJECT_EQUALS_FALSE);
262 	}
263 
264 	if (num1->pn_value.pnv_signed == num2->pn_value.pnv_signed)
265 		return _PROP_OBJECT_EQUALS_TRUE;
266 	else
267 		return _PROP_OBJECT_EQUALS_FALSE;
268 }
269 
270 static prop_number_t
271 _prop_number_alloc(const struct _prop_number_value *pnv)
272 {
273 	prop_number_t opn, pn, rpn;
274 
275 	_PROP_ONCE_RUN(_prop_number_init_once, _prop_number_init);
276 
277 	/*
278 	 * Check to see if this already exists in the tree.  If it does,
279 	 * we just retain it and return it.
280 	 */
281 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
282 	opn = _prop_rb_tree_find(&_prop_number_tree, pnv);
283 	if (opn != NULL) {
284 		prop_object_retain(opn);
285 		_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
286 		return (opn);
287 	}
288 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
289 
290 	/*
291 	 * Not in the tree.  Create it now.
292 	 */
293 
294 	pn = _PROP_POOL_GET(_prop_number_pool);
295 	if (pn == NULL)
296 		return (NULL);
297 
298 	_prop_object_init(&pn->pn_obj, &_prop_object_type_number);
299 
300 	pn->pn_value = *pnv;
301 
302 	/*
303 	 * We dropped the mutex when we allocated the new object, so
304 	 * we have to check again if it is in the tree.
305 	 */
306 	_PROP_MUTEX_LOCK(_prop_number_tree_mutex);
307 	opn = _prop_rb_tree_find(&_prop_number_tree, pnv);
308 	if (opn != NULL) {
309 		prop_object_retain(opn);
310 		_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
311 		_PROP_POOL_PUT(_prop_number_pool, pn);
312 		return (opn);
313 	}
314 	rpn = _prop_rb_tree_insert_node(&_prop_number_tree, pn);
315 	_PROP_ASSERT(rpn == pn);
316 	_PROP_MUTEX_UNLOCK(_prop_number_tree_mutex);
317 	return (rpn);
318 }
319 
320 /*
321  * prop_number_create_integer --
322  *	Create a prop_number_t and initialize it with the
323  *	provided integer value.
324  */
325 prop_number_t
326 prop_number_create_integer(int64_t val)
327 {
328 	struct _prop_number_value pnv;
329 
330 	memset(&pnv, 0, sizeof(pnv));
331 	pnv.pnv_signed = val;
332 	pnv.pnv_is_unsigned = false;
333 
334 	return (_prop_number_alloc(&pnv));
335 }
336 
337 /*
338  * prop_number_create_unsigned_integer --
339  *	Create a prop_number_t and initialize it with the
340  *	provided unsigned integer value.
341  */
342 prop_number_t
343 prop_number_create_unsigned_integer(uint64_t val)
344 {
345 	struct _prop_number_value pnv;
346 
347 	memset(&pnv, 0, sizeof(pnv));
348 	pnv.pnv_unsigned = val;
349 	pnv.pnv_is_unsigned = true;
350 
351 	return (_prop_number_alloc(&pnv));
352 }
353 
354 /*
355  * prop_number_copy --
356  *	Copy a prop_number_t.
357  */
358 prop_number_t
359 prop_number_copy(prop_number_t opn)
360 {
361 
362 	if (! prop_object_is_number(opn))
363 		return (NULL);
364 
365 	/*
366 	 * Because we only ever allocate one object for any given
367 	 * value, this can be reduced to a simple retain operation.
368 	 */
369 	prop_object_retain(opn);
370 	return (opn);
371 }
372 
373 /*
374  * prop_number_unsigned --
375  *	Returns true if the prop_number_t has an unsigned value.
376  */
377 bool
378 prop_number_unsigned(prop_number_t pn)
379 {
380 
381 	return (pn->pn_value.pnv_is_unsigned);
382 }
383 
384 /*
385  * prop_number_size --
386  *	Return the size, in bits, required to hold the value of
387  *	the specified number.
388  */
389 int
390 prop_number_size(prop_number_t pn)
391 {
392 	struct _prop_number_value *pnv;
393 
394 	if (! prop_object_is_number(pn))
395 		return (0);
396 
397 	pnv = &pn->pn_value;
398 
399 	if (pnv->pnv_is_unsigned) {
400 		if (pnv->pnv_unsigned > UINT32_MAX)
401 			return (64);
402 		if (pnv->pnv_unsigned > UINT16_MAX)
403 			return (32);
404 		if (pnv->pnv_unsigned > UINT8_MAX)
405 			return (16);
406 		return (8);
407 	}
408 
409 	if (pnv->pnv_signed > INT32_MAX || pnv->pnv_signed < INT32_MIN)
410 	    	return (64);
411 	if (pnv->pnv_signed > INT16_MAX || pnv->pnv_signed < INT16_MIN)
412 		return (32);
413 	if (pnv->pnv_signed > INT8_MAX  || pnv->pnv_signed < INT8_MIN)
414 		return (16);
415 	return (8);
416 }
417 
418 /*
419  * prop_number_integer_value --
420  *	Get the integer value of a prop_number_t.
421  */
422 int64_t
423 prop_number_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_signed);
434 }
435 
436 /*
437  * prop_number_unsigned_integer_value --
438  *	Get the unsigned integer value of a prop_number_t.
439  */
440 uint64_t
441 prop_number_unsigned_integer_value(prop_number_t pn)
442 {
443 
444 	/*
445 	 * XXX Impossible to distinguish between "not a prop_number_t"
446 	 * XXX and "prop_number_t has a value of 0".
447 	 */
448 	if (! prop_object_is_number(pn))
449 		return (0);
450 
451 	return (pn->pn_value.pnv_unsigned);
452 }
453 
454 /*
455  * prop_number_equals --
456  *	Return true if two numbers are equivalent.
457  */
458 bool
459 prop_number_equals(prop_number_t num1, prop_number_t num2)
460 {
461 	if (!prop_object_is_number(num1) || !prop_object_is_number(num2))
462 		return (false);
463 
464 	return (prop_object_equals(num1, num2));
465 }
466 
467 /*
468  * prop_number_equals_integer --
469  *	Return true if the number is equivalent to the specified integer.
470  */
471 bool
472 prop_number_equals_integer(prop_number_t pn, int64_t val)
473 {
474 
475 	if (! prop_object_is_number(pn))
476 		return (false);
477 
478 	if (pn->pn_value.pnv_is_unsigned &&
479 	    (pn->pn_value.pnv_unsigned > INT64_MAX || val < 0))
480 		return (false);
481 
482 	return (pn->pn_value.pnv_signed == val);
483 }
484 
485 /*
486  * prop_number_equals_unsigned_integer --
487  *	Return true if the number is equivalent to the specified
488  *	unsigned integer.
489  */
490 bool
491 prop_number_equals_unsigned_integer(prop_number_t pn, uint64_t val)
492 {
493 
494 	if (! prop_object_is_number(pn))
495 		return (false);
496 
497 	if (! pn->pn_value.pnv_is_unsigned &&
498 	    (pn->pn_value.pnv_signed < 0 || val > INT64_MAX))
499 		return (false);
500 
501 	return (pn->pn_value.pnv_unsigned == val);
502 }
503 
504 static bool
505 _prop_number_internalize_unsigned(struct _prop_object_internalize_context *ctx,
506 				  struct _prop_number_value *pnv)
507 {
508 	char *cp;
509 
510 	_PROP_ASSERT(/*CONSTCOND*/sizeof(unsigned long long) ==
511 		     sizeof(uint64_t));
512 
513 #ifndef _KERNEL
514 	errno = 0;
515 #endif
516 	pnv->pnv_unsigned = (uint64_t) strtoull(ctx->poic_cp, &cp, 0);
517 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
518 	if (pnv->pnv_unsigned == UINT64_MAX && errno == ERANGE)
519 		return (false);
520 #endif
521 	pnv->pnv_is_unsigned = true;
522 	ctx->poic_cp = cp;
523 
524 	return (true);
525 }
526 
527 static bool
528 _prop_number_internalize_signed(struct _prop_object_internalize_context *ctx,
529 				struct _prop_number_value *pnv)
530 {
531 	char *cp;
532 
533 	_PROP_ASSERT(/*CONSTCOND*/sizeof(long long) == sizeof(int64_t));
534 
535 #ifndef _KERNEL
536 	errno = 0;
537 #endif
538 	pnv->pnv_signed = (int64_t) strtoll(ctx->poic_cp, &cp, 0);
539 #ifndef _KERNEL		/* XXX can't check for ERANGE in the kernel */
540 	if ((pnv->pnv_signed == INT64_MAX || pnv->pnv_signed == INT64_MIN) &&
541 	    errno == ERANGE)
542 	    	return (false);
543 #endif
544 	pnv->pnv_is_unsigned = false;
545 	ctx->poic_cp = cp;
546 
547 	return (true);
548 }
549 
550 /*
551  * _prop_number_internalize --
552  *	Parse a <number>...</number> and return the object created from
553  *	the external representation.
554  */
555 /* ARGSUSED */
556 bool
557 _prop_number_internalize(prop_stack_t stack, prop_object_t *obj,
558     struct _prop_object_internalize_context *ctx)
559 {
560 	struct _prop_number_value pnv;
561 
562 	memset(&pnv, 0, sizeof(pnv));
563 
564 	/* No attributes, no empty elements. */
565 	if (ctx->poic_tagattr != NULL || ctx->poic_is_empty_element)
566 		return (true);
567 
568 	/*
569 	 * If the first character is '-', then we treat as signed.
570 	 * If the first two characters are "0x" (i.e. the number is
571 	 * in hex), then we treat as unsigned.  Otherwise, we try
572 	 * signed first, and if that fails (presumably due to ERANGE),
573 	 * then we switch to unsigned.
574 	 */
575 	if (ctx->poic_cp[0] == '-') {
576 		if (_prop_number_internalize_signed(ctx, &pnv) == false)
577 			return (true);
578 	} else if (ctx->poic_cp[0] == '0' && ctx->poic_cp[1] == 'x') {
579 		if (_prop_number_internalize_unsigned(ctx, &pnv) == false)
580 			return (true);
581 	} else {
582 		if (_prop_number_internalize_signed(ctx, &pnv) == false &&
583 		    _prop_number_internalize_unsigned(ctx, &pnv) == false)
584 		    	return (true);
585 	}
586 
587 	if (_prop_object_internalize_find_tag(ctx, "integer",
588 					      _PROP_TAG_TYPE_END) == false)
589 		return (true);
590 
591 	*obj = _prop_number_alloc(&pnv);
592 	return (true);
593 }
594