rcsnum.c revision 1.31 
1/*	$OpenBSD: rcsnum.c,v 1.31 2006/03/30 23:06:25 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
33
34static int	 rcsnum_setsize(RCSNUM *, u_int);
35static char	*rcsnum_itoa(u_int16_t, char *, size_t);
36
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 = (RCSNUM *)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
105	if ((nump == NULL) || (nump->rn_len == 0)) {
106		buf[0] = '\0';
107		return (buf);
108	}
109
110	strlcpy(buf, rcsnum_itoa(nump->rn_id[0], buf, blen), blen);
111	for (i = 1; i < nump->rn_len; i++) {
112		strlcat(buf, ".", blen);
113		strlcat(buf, rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp)),
114		    blen);
115	}
116
117	return (buf);
118}
119
120static char *
121rcsnum_itoa(u_int16_t num, char *buf, size_t len)
122{
123	u_int16_t i;
124	char *p;
125
126	if (num == 0)
127		return "0";
128
129	p = buf + len - 1;
130	i = num;
131	bzero(buf, len);
132	while (i) {
133		*--p = '0' + (i % 10);
134		i  /= 10;
135	}
136	return (p);
137}
138
139/*
140 * rcsnum_cpy()
141 *
142 * Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
143 * numbers deep.  If <depth> is 0, there is no depth limit.
144 */
145void
146rcsnum_cpy(const RCSNUM *nsrc, RCSNUM *ndst, u_int depth)
147{
148	u_int len;
149	void *tmp;
150
151	len = nsrc->rn_len;
152	if ((depth != 0) && (len > depth))
153		len = depth;
154
155	tmp = xrealloc(ndst->rn_id, len, sizeof(len));
156	ndst->rn_id = (u_int16_t *)tmp;
157	ndst->rn_len = len;
158	/* Overflow checked in xrealloc(). */
159	memcpy(ndst->rn_id, nsrc->rn_id, len * sizeof(len));
160}
161
162/*
163 * rcsnum_cmp()
164 *
165 * Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
166 * <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
167 * The <depth> argument specifies how many numbers deep should be checked for
168 * the result.  A value of 0 means that the depth will be the minimum of the
169 * two numbers.
170 */
171int
172rcsnum_cmp(const RCSNUM *n1, const RCSNUM *n2, u_int depth)
173{
174	int res;
175	u_int i;
176	size_t slen;
177
178	slen = MIN(n1->rn_len, n2->rn_len);
179	if ((depth != 0) && (slen > depth))
180		slen = depth;
181
182	for (i = 0; i < slen; i++) {
183		res = n1->rn_id[i] - n2->rn_id[i];
184		if (res < 0)
185			return (1);
186		else if (res > 0)
187			return (-1);
188	}
189
190	if (n1->rn_len > n2->rn_len)
191		return (-1);
192	else if (n2->rn_len > n1->rn_len)
193		return (1);
194
195	return (0);
196}
197
198/*
199 * rcsnum_aton()
200 *
201 * Translate the string <str> containing a sequence of digits and periods into
202 * its binary representation, which is stored in <nump>.  The address of the
203 * first byte not part of the number is stored in <ep> on return, if it is not
204 * NULL.
205 * Returns 0 on success, or -1 on failure.
206 */
207int
208rcsnum_aton(const char *str, char **ep, RCSNUM *nump)
209{
210	u_int32_t val;
211	const char *sp;
212	void *tmp;
213	char *s;
214
215	if (nump->rn_id == NULL)
216		nump->rn_id = (u_int16_t *)xmalloc(sizeof(u_int16_t));
217
218	nump->rn_len = 0;
219	nump->rn_id[0] = 0;
220
221	for (sp = str;; sp++) {
222		if (!isdigit(*sp) && (*sp != '.'))
223			break;
224
225		if (*sp == '.') {
226			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
227				rcs_errno = RCS_ERR_BADNUM;
228				goto rcsnum_aton_failed;
229			}
230
231			nump->rn_len++;
232			tmp = xrealloc(nump->rn_id,
233			    nump->rn_len + 1, sizeof(u_int16_t));
234			nump->rn_id = (u_int16_t *)tmp;
235			nump->rn_id[nump->rn_len] = 0;
236			continue;
237		}
238
239		val = (nump->rn_id[nump->rn_len] * 10) + (*sp - 0x30);
240		if (val > RCSNUM_MAXNUM)
241			fatal("RCSNUM overflow!");
242
243		nump->rn_id[nump->rn_len] = val;
244	}
245
246	if (ep != NULL)
247		*(const char **)ep = sp;
248
249	/*
250	 * Handle "magic" RCS branch numbers.
251	 *
252	 * What are they?
253	 *
254	 * Magic branch numbers have an extra .0. at the second farmost
255	 * rightside of the branch number, so instead of having an odd
256	 * number of dot-separated decimals, it will have an even number.
257	 *
258	 * Now, according to all the documentation i've found on the net
259	 * about this, cvs does this for "efficiency reasons", i'd like
260	 * to hear one.
261	 *
262	 * We just make sure we remove the .0. from in the branch number.
263	 *
264	 * XXX - for compatibility reasons with GNU cvs we _need_
265	 * to skip this part for the 'log' command, apparently it does
266	 * show the magic branches for an unknown and probably
267	 * completely insane and not understandable reason in that output.
268	 *
269	 */
270#if !defined(RCSPROG)
271	if ((nump->rn_len > 2) && (nump->rn_id[nump->rn_len - 1] == 0)
272	    && (cvs_cmdop != CVS_OP_LOG)) {
273#else
274	if ((nump->rn_len > 2) && (nump->rn_id[nump->rn_len - 1] == 0)) {
275#endif
276		/*
277		 * Look for ".0.x" at the end of the branch number.
278		 */
279		if ((s = strrchr(str, '.')) != NULL) {
280			s--;
281			while (*s != '.')
282				s--;
283
284			/*
285			 * If we have a "magic" branch, adjust it
286			 * so the .0. is removed.
287			 */
288			if (!strncmp(s, RCS_MAGIC_BRANCH,
289			    strlen(RCS_MAGIC_BRANCH))) {
290				nump->rn_id[nump->rn_len - 1] =
291				    nump->rn_id[nump->rn_len];
292				nump->rn_len--;
293			}
294		}
295	}
296
297	/* We can't have a single-digit rcs number. */
298	if (nump->rn_len == 0) {
299		tmp = xrealloc(nump->rn_id,
300		    nump->rn_len + 1, sizeof(u_int16_t));
301		nump->rn_id = (u_int16_t *)tmp;
302		nump->rn_id[nump->rn_len + 1] = 0;
303		nump->rn_len++;
304	}
305
306	nump->rn_len++;
307	return (nump->rn_len);
308
309rcsnum_aton_failed:
310	nump->rn_len = 0;
311	xfree(nump->rn_id);
312	nump->rn_id = NULL;
313	return (-1);
314}
315
316/*
317 * rcsnum_inc()
318 *
319 * Increment the revision number specified in <num>.
320 * Returns a pointer to the <num> on success, or NULL on failure.
321 */
322RCSNUM *
323rcsnum_inc(RCSNUM *num)
324{
325	if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
326		return (NULL);
327	num->rn_id[num->rn_len - 1]++;
328	return (num);
329}
330
331/*
332 * rcsnum_dec()
333 *
334 * Decreases the revision number specified in <num>, if doing so will not
335 * result in an ending value below 1. E.g. 4.2 will go to 4.1 but 4.1 will
336 * be returned as 4.1.
337 */
338RCSNUM *
339rcsnum_dec(RCSNUM *num)
340{
341	/* XXX - Is it an error for the number to be 0? */
342	if (num->rn_id[num->rn_len - 1] <= 1)
343		return (num);
344	num->rn_id[num->rn_len - 1]--;
345	return (num);
346}
347
348/*
349 * rcsnum_revtobr()
350 *
351 * Retrieve the branch number associated with the revision number <num>.
352 * If <num> is a branch revision, the returned value will be the same
353 * number as the argument.
354 */
355RCSNUM *
356rcsnum_revtobr(const RCSNUM *num)
357{
358	RCSNUM *brnum;
359
360	if (num->rn_len < 2)
361		return (NULL);
362
363	brnum = rcsnum_alloc();
364	rcsnum_cpy(num, brnum, 0);
365
366	if (!RCSNUM_ISBRANCH(brnum))
367		brnum->rn_len--;
368
369	return (brnum);
370}
371
372/*
373 * rcsnum_brtorev()
374 *
375 * Retrieve the initial revision number associated with the branch number <num>.
376 * If <num> is a revision number, an error will be returned.
377 */
378RCSNUM *
379rcsnum_brtorev(const RCSNUM *brnum)
380{
381	RCSNUM *num;
382
383	if (!RCSNUM_ISBRANCH(brnum)) {
384		return (NULL);
385	}
386
387	num = rcsnum_alloc();
388	if (rcsnum_setsize(num, brnum->rn_len + 1) < 0) {
389		rcsnum_free(num);
390		return (NULL);
391	}
392
393	rcsnum_cpy(brnum, num, brnum->rn_len);
394	num->rn_id[num->rn_len++] = 1;
395
396	return (num);
397}
398
399static int
400rcsnum_setsize(RCSNUM *num, u_int len)
401{
402	void *tmp;
403
404	tmp = xrealloc(num->rn_id, len, sizeof(u_int16_t));
405	num->rn_id = (u_int16_t *)tmp;
406	num->rn_len = len;
407	return (0);
408}
409