rcsnum.c revision 1.38 
1/*	$OpenBSD: rcsnum.c,v 1.38 2006/05/31 18:24:55 joris Exp $	*/
2/*
3 * Copyright (c) 2004 Jean-Francois Brousseau <jfb@openbsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. The name of the author may not be used to endorse or promote products
13 *    derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "includes.h"
28
29#include "cvs.h"
30#include "log.h"
31#include "rcs.h"
32
33static void	 rcsnum_setsize(RCSNUM *, u_int);
34static char	*rcsnum_itoa(u_int16_t, char *, size_t);
35
36int rcsnum_flags;
37
38/*
39 * rcsnum_alloc()
40 *
41 * Allocate an RCS number structure and return a pointer to it.
42 */
43RCSNUM *
44rcsnum_alloc(void)
45{
46	RCSNUM *rnp;
47
48	rnp = xmalloc(sizeof(*rnp));
49	rnp->rn_len = 0;
50	rnp->rn_id = NULL;
51
52	return (rnp);
53}
54
55/*
56 * rcsnum_parse()
57 *
58 * Parse a string specifying an RCS number and return the corresponding RCSNUM.
59 */
60RCSNUM *
61rcsnum_parse(const char *str)
62{
63	char *ep;
64	RCSNUM *num;
65
66	num = rcsnum_alloc();
67	if (rcsnum_aton(str, &ep, num) < 0 || *ep != '\0') {
68		rcsnum_free(num);
69		num = NULL;
70		if (*ep != '\0')
71			rcs_errno = RCS_ERR_BADNUM;
72	}
73
74	return (num);
75}
76
77/*
78 * rcsnum_free()
79 *
80 * Free an RCSNUM structure previously allocated with rcsnum_alloc().
81 */
82void
83rcsnum_free(RCSNUM *rn)
84{
85	if (rn->rn_id != NULL)
86		xfree(rn->rn_id);
87	xfree(rn);
88}
89
90/*
91 * rcsnum_tostr()
92 *
93 * Format the RCS number <nump> into a human-readable dot-separated
94 * representation and store the resulting string in <buf>, which is of size
95 * <blen>.
96 * Returns a pointer to the start of <buf>.  On failure <buf> is set to
97 * an empty string.
98 */
99char *
100rcsnum_tostr(const RCSNUM *nump, char *buf, size_t blen)
101{
102	u_int i;
103	char tmp[8];
104	size_t len;
105
106	if (nump == NULL || nump->rn_len == 0) {
107		buf[0] = '\0';
108		return (buf);
109	}
110
111	strlcpy(buf, rcsnum_itoa(nump->rn_id[0], buf, blen), blen);
112	for (i = 1; i < nump->rn_len; i++) {
113		len = strlcat(buf, ".", blen);
114		if (len >= blen)
115			fatal("rcsnum_tostr: overflow 1");
116
117		len = strlcat(buf,
118		    rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp)), blen);
119		if (len >= blen)
120			fatal("rcsnum_tostr: overflow 2");
121	}
122
123	return (buf);
124}
125
126static char *
127rcsnum_itoa(u_int16_t num, char *buf, size_t len)
128{
129	u_int16_t i;
130	char *p;
131
132	if (num == 0)
133		return "0";
134
135	p = buf + len - 1;
136	i = num;
137	bzero(buf, len);
138	while (i) {
139		*--p = '0' + (i % 10);
140		i  /= 10;
141	}
142	return (p);
143}
144
145/*
146 * rcsnum_cpy()
147 *
148 * Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
149 * numbers deep.  If <depth> is 0, there is no depth limit.
150 */
151void
152rcsnum_cpy(const RCSNUM *nsrc, RCSNUM *ndst, u_int depth)
153{
154	u_int len;
155	void *tmp;
156
157	len = nsrc->rn_len;
158	if (depth != 0 && len > depth)
159		len = depth;
160
161	tmp = xrealloc(ndst->rn_id, len, sizeof(len));
162	ndst->rn_id = tmp;
163	ndst->rn_len = len;
164	/* Overflow checked in xrealloc(). */
165	(void)memcpy(ndst->rn_id, nsrc->rn_id, len * sizeof(len));
166}
167
168/*
169 * rcsnum_cmp()
170 *
171 * Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
172 * <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
173 * The <depth> argument specifies how many numbers deep should be checked for
174 * the result.  A value of 0 means that the depth will be the minimum of the
175 * two numbers.
176 */
177int
178rcsnum_cmp(RCSNUM *n1, RCSNUM *n2, u_int depth)
179{
180	int res;
181	u_int i;
182	size_t slen;
183
184	if (!rcsnum_differ(n1, n2))
185		return (0);
186
187	slen = MIN(n1->rn_len, n2->rn_len);
188	if (depth != 0 && slen > depth)
189		slen = depth;
190
191	for (i = 0; i < slen; i++) {
192		res = n1->rn_id[i] - n2->rn_id[i];
193		if (res < 0)
194			return (1);
195		else if (res > 0)
196			return (-1);
197	}
198
199	if (n1->rn_len > n2->rn_len)
200		return (-1);
201	else if (n2->rn_len > n1->rn_len)
202		return (1);
203
204	return (0);
205}
206
207/*
208 * rcsnum_aton()
209 *
210 * Translate the string <str> containing a sequence of digits and periods into
211 * its binary representation, which is stored in <nump>.  The address of the
212 * first byte not part of the number is stored in <ep> on return, if it is not
213 * NULL.
214 * Returns 0 on success, or -1 on failure.
215 */
216int
217rcsnum_aton(const char *str, char **ep, RCSNUM *nump)
218{
219	u_int32_t val;
220	const char *sp;
221	void *tmp;
222	char *s;
223
224	if (nump->rn_id == NULL)
225		nump->rn_id = xmalloc(sizeof(*(nump->rn_id)));
226
227	nump->rn_len = 0;
228	nump->rn_id[0] = 0;
229
230	for (sp = str;; sp++) {
231		if (!isdigit(*sp) && (*sp != '.'))
232			break;
233
234		if (*sp == '.') {
235			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
236				rcs_errno = RCS_ERR_BADNUM;
237				goto rcsnum_aton_failed;
238			}
239
240			nump->rn_len++;
241			tmp = xrealloc(nump->rn_id,
242			    nump->rn_len + 1, sizeof(*(nump->rn_id)));
243			nump->rn_id = tmp;
244			nump->rn_id[nump->rn_len] = 0;
245			continue;
246		}
247
248		val = (nump->rn_id[nump->rn_len] * 10) + (*sp - 0x30);
249		if (val > RCSNUM_MAXNUM)
250			fatal("RCSNUM overflow!");
251
252		nump->rn_id[nump->rn_len] = val;
253	}
254
255	if (ep != NULL)
256		*(const char **)ep = sp;
257
258	/*
259	 * Handle "magic" RCS branch numbers.
260	 *
261	 * What are they?
262	 *
263	 * Magic branch numbers have an extra .0. at the second farmost
264	 * rightside of the branch number, so instead of having an odd
265	 * number of dot-separated decimals, it will have an even number.
266	 *
267	 * Now, according to all the documentation i've found on the net
268	 * about this, cvs does this for "efficiency reasons", i'd like
269	 * to hear one.
270	 *
271	 * We just make sure we remove the .0. from in the branch number.
272	 *
273	 * XXX - for compatibility reasons with GNU cvs we _need_
274	 * to skip this part for the 'log' command, apparently it does
275	 * show the magic branches for an unknown and probably
276	 * completely insane and not understandable reason in that output.
277	 *
278	 */
279	if (nump->rn_len > 2 && nump->rn_id[nump->rn_len - 1] == 0
280	    && !(rcsnum_flags & RCSNUM_NO_MAGIC)) {
281		/*
282		 * Look for ".0.x" at the end of the branch number.
283		 */
284		if ((s = strrchr(str, '.')) != NULL) {
285			s--;
286			while (*s != '.')
287				s--;
288
289			/*
290			 * If we have a "magic" branch, adjust it
291			 * so the .0. is removed.
292			 */
293			if (!strncmp(s, RCS_MAGIC_BRANCH,
294			    strlen(RCS_MAGIC_BRANCH))) {
295				nump->rn_id[nump->rn_len - 1] =
296				    nump->rn_id[nump->rn_len];
297				nump->rn_len--;
298			}
299		}
300	}
301
302	/* We can't have a single-digit rcs number. */
303	if (nump->rn_len == 0) {
304		tmp = xrealloc(nump->rn_id,
305		    nump->rn_len + 1, sizeof(*(nump->rn_id)));
306		nump->rn_id = tmp;
307		nump->rn_id[nump->rn_len + 1] = 0;
308		nump->rn_len++;
309	}
310
311	nump->rn_len++;
312	return (nump->rn_len);
313
314rcsnum_aton_failed:
315	nump->rn_len = 0;
316	xfree(nump->rn_id);
317	nump->rn_id = NULL;
318	return (-1);
319}
320
321/*
322 * rcsnum_inc()
323 *
324 * Increment the revision number specified in <num>.
325 * Returns a pointer to the <num> on success, or NULL on failure.
326 */
327RCSNUM *
328rcsnum_inc(RCSNUM *num)
329{
330	if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
331		return (NULL);
332	num->rn_id[num->rn_len - 1]++;
333	return (num);
334}
335
336/*
337 * rcsnum_dec()
338 *
339 * Decreases the revision number specified in <num>, if doing so will not
340 * result in an ending value below 1. E.g. 4.2 will go to 4.1 but 4.1 will
341 * be returned as 4.1.
342 */
343RCSNUM *
344rcsnum_dec(RCSNUM *num)
345{
346	/* XXX - Is it an error for the number to be 0? */
347	if (num->rn_id[num->rn_len - 1] <= 1)
348		return (num);
349	num->rn_id[num->rn_len - 1]--;
350	return (num);
351}
352
353/*
354 * rcsnum_revtobr()
355 *
356 * Retrieve the branch number associated with the revision number <num>.
357 * If <num> is a branch revision, the returned value will be the same
358 * number as the argument.
359 */
360RCSNUM *
361rcsnum_revtobr(const RCSNUM *num)
362{
363	RCSNUM *brnum;
364
365	if (num->rn_len < 2)
366		return (NULL);
367
368	brnum = rcsnum_alloc();
369	rcsnum_cpy(num, brnum, 0);
370
371	if (!RCSNUM_ISBRANCH(brnum))
372		brnum->rn_len--;
373
374	return (brnum);
375}
376
377/*
378 * rcsnum_brtorev()
379 *
380 * Retrieve the initial revision number associated with the branch number <num>.
381 * If <num> is a revision number, an error will be returned.
382 */
383RCSNUM *
384rcsnum_brtorev(const RCSNUM *brnum)
385{
386	RCSNUM *num;
387
388	if (!RCSNUM_ISBRANCH(brnum)) {
389		return (NULL);
390	}
391
392	num = rcsnum_alloc();
393	rcsnum_setsize(num, brnum->rn_len + 1);
394	rcsnum_cpy(brnum, num, brnum->rn_len);
395	num->rn_id[num->rn_len++] = 1;
396
397	return (num);
398}
399
400static void
401rcsnum_setsize(RCSNUM *num, u_int len)
402{
403	void *tmp;
404
405	tmp = xrealloc(num->rn_id, len, sizeof(*(num->rn_id)));
406	num->rn_id = tmp;
407	num->rn_len = len;
408}
409
410int
411rcsnum_differ(RCSNUM *r1, RCSNUM *r2)
412{
413	int i, len;
414
415	if (r1->rn_len != r2->rn_len)
416		return (1);
417
418	len = MIN(r1->rn_len, r2->rn_len);
419	for (i = 0; i < len; i++) {
420		if (r1->rn_id[i] != r2->rn_id[i])
421			return (1);
422	}
423
424	return (0);
425}
426