rcsnum.c revision 1.36 
1/*	$OpenBSD: rcsnum.c,v 1.36 2006/04/14 22:33:15 niallo 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
33
34static void	 rcsnum_setsize(RCSNUM *, u_int);
35static char	*rcsnum_itoa(u_int16_t, char *, size_t);
36
37int rcsnum_flags;
38
39/*
40 * rcsnum_alloc()
41 *
42 * Allocate an RCS number structure and return a pointer to it.
43 */
44RCSNUM *
45rcsnum_alloc(void)
46{
47	RCSNUM *rnp;
48
49	rnp = xmalloc(sizeof(*rnp));
50	rnp->rn_len = 0;
51	rnp->rn_id = NULL;
52
53	return (rnp);
54}
55
56/*
57 * rcsnum_parse()
58 *
59 * Parse a string specifying an RCS number and return the corresponding RCSNUM.
60 */
61RCSNUM *
62rcsnum_parse(const char *str)
63{
64	char *ep;
65	RCSNUM *num;
66
67	num = rcsnum_alloc();
68	if (rcsnum_aton(str, &ep, num) < 0 || *ep != '\0') {
69		rcsnum_free(num);
70		num = NULL;
71		if (*ep != '\0')
72			rcs_errno = RCS_ERR_BADNUM;
73	}
74
75	return (num);
76}
77
78/*
79 * rcsnum_free()
80 *
81 * Free an RCSNUM structure previously allocated with rcsnum_alloc().
82 */
83void
84rcsnum_free(RCSNUM *rn)
85{
86	if (rn->rn_id != NULL)
87		xfree(rn->rn_id);
88	xfree(rn);
89}
90
91/*
92 * rcsnum_tostr()
93 *
94 * Format the RCS number <nump> into a human-readable dot-separated
95 * representation and store the resulting string in <buf>, which is of size
96 * <blen>.
97 * Returns a pointer to the start of <buf>.  On failure <buf> is set to
98 * an empty string.
99 */
100char *
101rcsnum_tostr(const RCSNUM *nump, char *buf, size_t blen)
102{
103	u_int i;
104	char tmp[8];
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		strlcat(buf, ".", blen);
114		strlcat(buf, rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp)),
115		    blen);
116	}
117
118	return (buf);
119}
120
121static char *
122rcsnum_itoa(u_int16_t num, char *buf, size_t len)
123{
124	u_int16_t i;
125	char *p;
126
127	if (num == 0)
128		return "0";
129
130	p = buf + len - 1;
131	i = num;
132	bzero(buf, len);
133	while (i) {
134		*--p = '0' + (i % 10);
135		i  /= 10;
136	}
137	return (p);
138}
139
140/*
141 * rcsnum_cpy()
142 *
143 * Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
144 * numbers deep.  If <depth> is 0, there is no depth limit.
145 */
146void
147rcsnum_cpy(const RCSNUM *nsrc, RCSNUM *ndst, u_int depth)
148{
149	u_int len;
150	void *tmp;
151
152	len = nsrc->rn_len;
153	if (depth != 0 && len > depth)
154		len = depth;
155
156	tmp = xrealloc(ndst->rn_id, len, sizeof(len));
157	ndst->rn_id = tmp;
158	ndst->rn_len = len;
159	/* Overflow checked in xrealloc(). */
160	(void)memcpy(ndst->rn_id, nsrc->rn_id, len * sizeof(len));
161}
162
163/*
164 * rcsnum_cmp()
165 *
166 * Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
167 * <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
168 * The <depth> argument specifies how many numbers deep should be checked for
169 * the result.  A value of 0 means that the depth will be the minimum of the
170 * two numbers.
171 */
172int
173rcsnum_cmp(const RCSNUM *n1, const RCSNUM *n2, u_int depth)
174{
175	int res;
176	u_int i;
177	size_t slen;
178
179	slen = MIN(n1->rn_len, n2->rn_len);
180	if (depth != 0 && slen > depth)
181		slen = depth;
182
183	for (i = 0; i < slen; i++) {
184		res = n1->rn_id[i] - n2->rn_id[i];
185		if (res < 0)
186			return (1);
187		else if (res > 0)
188			return (-1);
189	}
190
191	if (n1->rn_len > n2->rn_len)
192		return (-1);
193	else if (n2->rn_len > n1->rn_len)
194		return (1);
195
196	return (0);
197}
198
199/*
200 * rcsnum_aton()
201 *
202 * Translate the string <str> containing a sequence of digits and periods into
203 * its binary representation, which is stored in <nump>.  The address of the
204 * first byte not part of the number is stored in <ep> on return, if it is not
205 * NULL.
206 * Returns 0 on success, or -1 on failure.
207 */
208int
209rcsnum_aton(const char *str, char **ep, RCSNUM *nump)
210{
211	u_int32_t val;
212	const char *sp;
213	void *tmp;
214	char *s;
215
216	if (nump->rn_id == NULL)
217		nump->rn_id = xmalloc(sizeof(*(nump->rn_id)));
218
219	nump->rn_len = 0;
220	nump->rn_id[0] = 0;
221
222	for (sp = str;; sp++) {
223		if (!isdigit(*sp) && (*sp != '.'))
224			break;
225
226		if (*sp == '.') {
227			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
228				rcs_errno = RCS_ERR_BADNUM;
229				goto rcsnum_aton_failed;
230			}
231
232			nump->rn_len++;
233			tmp = xrealloc(nump->rn_id,
234			    nump->rn_len + 1, sizeof(*(nump->rn_id)));
235			nump->rn_id = tmp;
236			nump->rn_id[nump->rn_len] = 0;
237			continue;
238		}
239
240		val = (nump->rn_id[nump->rn_len] * 10) + (*sp - 0x30);
241		if (val > RCSNUM_MAXNUM)
242			fatal("RCSNUM overflow!");
243
244		nump->rn_id[nump->rn_len] = val;
245	}
246
247	if (ep != NULL)
248		*(const char **)ep = sp;
249
250	/*
251	 * Handle "magic" RCS branch numbers.
252	 *
253	 * What are they?
254	 *
255	 * Magic branch numbers have an extra .0. at the second farmost
256	 * rightside of the branch number, so instead of having an odd
257	 * number of dot-separated decimals, it will have an even number.
258	 *
259	 * Now, according to all the documentation i've found on the net
260	 * about this, cvs does this for "efficiency reasons", i'd like
261	 * to hear one.
262	 *
263	 * We just make sure we remove the .0. from in the branch number.
264	 *
265	 * XXX - for compatibility reasons with GNU cvs we _need_
266	 * to skip this part for the 'log' command, apparently it does
267	 * show the magic branches for an unknown and probably
268	 * completely insane and not understandable reason in that output.
269	 *
270	 */
271	if (nump->rn_len > 2 && nump->rn_id[nump->rn_len - 1] == 0
272	    && !(rcsnum_flags & RCSNUM_NO_MAGIC)) {
273		/*
274		 * Look for ".0.x" at the end of the branch number.
275		 */
276		if ((s = strrchr(str, '.')) != NULL) {
277			s--;
278			while (*s != '.')
279				s--;
280
281			/*
282			 * If we have a "magic" branch, adjust it
283			 * so the .0. is removed.
284			 */
285			if (!strncmp(s, RCS_MAGIC_BRANCH,
286			    strlen(RCS_MAGIC_BRANCH))) {
287				nump->rn_id[nump->rn_len - 1] =
288				    nump->rn_id[nump->rn_len];
289				nump->rn_len--;
290			}
291		}
292	}
293
294	/* We can't have a single-digit rcs number. */
295	if (nump->rn_len == 0) {
296		tmp = xrealloc(nump->rn_id,
297		    nump->rn_len + 1, sizeof(*(nump->rn_id)));
298		nump->rn_id = tmp;
299		nump->rn_id[nump->rn_len + 1] = 0;
300		nump->rn_len++;
301	}
302
303	nump->rn_len++;
304	return (nump->rn_len);
305
306rcsnum_aton_failed:
307	nump->rn_len = 0;
308	xfree(nump->rn_id);
309	nump->rn_id = NULL;
310	return (-1);
311}
312
313/*
314 * rcsnum_inc()
315 *
316 * Increment the revision number specified in <num>.
317 * Returns a pointer to the <num> on success, or NULL on failure.
318 */
319RCSNUM *
320rcsnum_inc(RCSNUM *num)
321{
322	if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
323		return (NULL);
324	num->rn_id[num->rn_len - 1]++;
325	return (num);
326}
327
328/*
329 * rcsnum_dec()
330 *
331 * Decreases the revision number specified in <num>, if doing so will not
332 * result in an ending value below 1. E.g. 4.2 will go to 4.1 but 4.1 will
333 * be returned as 4.1.
334 */
335RCSNUM *
336rcsnum_dec(RCSNUM *num)
337{
338	/* XXX - Is it an error for the number to be 0? */
339	if (num->rn_id[num->rn_len - 1] <= 1)
340		return (num);
341	num->rn_id[num->rn_len - 1]--;
342	return (num);
343}
344
345/*
346 * rcsnum_revtobr()
347 *
348 * Retrieve the branch number associated with the revision number <num>.
349 * If <num> is a branch revision, the returned value will be the same
350 * number as the argument.
351 */
352RCSNUM *
353rcsnum_revtobr(const RCSNUM *num)
354{
355	RCSNUM *brnum;
356
357	if (num->rn_len < 2)
358		return (NULL);
359
360	brnum = rcsnum_alloc();
361	rcsnum_cpy(num, brnum, 0);
362
363	if (!RCSNUM_ISBRANCH(brnum))
364		brnum->rn_len--;
365
366	return (brnum);
367}
368
369/*
370 * rcsnum_brtorev()
371 *
372 * Retrieve the initial revision number associated with the branch number <num>.
373 * If <num> is a revision number, an error will be returned.
374 */
375RCSNUM *
376rcsnum_brtorev(const RCSNUM *brnum)
377{
378	RCSNUM *num;
379
380	if (!RCSNUM_ISBRANCH(brnum)) {
381		return (NULL);
382	}
383
384	num = rcsnum_alloc();
385	rcsnum_setsize(num, brnum->rn_len + 1);
386	rcsnum_cpy(brnum, num, brnum->rn_len);
387	num->rn_id[num->rn_len++] = 1;
388
389	return (num);
390}
391
392static void
393rcsnum_setsize(RCSNUM *num, u_int len)
394{
395	void *tmp;
396
397	tmp = xrealloc(num->rn_id, len, sizeof(*(num->rn_id)));
398	num->rn_id = tmp;
399	num->rn_len = len;
400}
401