rcsnum.c revision 1.20 
1/*	$OpenBSD: rcsnum.c,v 1.20 2005/12/27 16:08:26 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 <sys/param.h>
28
29#include <ctype.h>
30#include <stdio.h>
31#include <stdlib.h>
32#include <string.h>
33
34#include "cvs.h"
35#include "log.h"
36#include "rcs.h"
37
38
39static int	rcsnum_setsize(RCSNUM *, u_int);
40static char     *rcsnum_itoa(u_int16_t, char *, size_t);
41
42
43/*
44 * rcsnum_alloc()
45 *
46 * Allocate an RCS number structure and return a pointer to it on success,
47 * or NULL on failure.
48 */
49RCSNUM *
50rcsnum_alloc(void)
51{
52	RCSNUM *rnp;
53
54	rnp = (RCSNUM *)xmalloc(sizeof(*rnp));
55	rnp->rn_len = 0;
56	rnp->rn_id = NULL;
57
58	return (rnp);
59}
60
61/*
62 * rcsnum_parse()
63 *
64 * Parse a string specifying an RCS number and return the corresponding RCSNUM.
65 */
66RCSNUM *
67rcsnum_parse(const char *str)
68{
69	char *ep;
70	RCSNUM *num;
71
72	num = rcsnum_alloc();
73	if ((rcsnum_aton(str, &ep, num) < 0) || (*ep != '\0')) {
74		rcsnum_free(num);
75		num = NULL;
76		if (*ep != '\0')
77			rcs_errno = RCS_ERR_BADNUM;
78	}
79
80	return (num);
81}
82
83/*
84 * rcsnum_free()
85 *
86 * Free an RCSNUM structure previously allocated with rcsnum_alloc().
87 */
88void
89rcsnum_free(RCSNUM *rn)
90{
91	if (rn->rn_id != NULL)
92		xfree(rn->rn_id);
93	xfree(rn);
94}
95
96/*
97 * rcsnum_tostr()
98 *
99 * Format the RCS number <nump> into a human-readable dot-separated
100 * representation and store the resulting string in <buf>, which is of size
101 * <blen>.
102 * Returns a pointer to the start of <buf> on success, or NULL on failure.
103 */
104char *
105rcsnum_tostr(const RCSNUM *nump, char *buf, size_t blen)
106{
107	u_int i;
108	char tmp[8];
109
110	if ((nump == NULL) || (nump->rn_len == 0)) {
111		buf[0] = '\0';
112		return (buf);
113	}
114
115	strlcpy(buf, rcsnum_itoa(nump->rn_id[0], buf, blen), blen);
116	for (i = 1; i < nump->rn_len; i++) {
117		strlcat(buf, ".", blen);
118		strlcat(buf, rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp)),
119		    blen);
120	}
121
122	return (buf);
123}
124
125static char *
126rcsnum_itoa(u_int16_t num, char *buf, size_t len)
127{
128        u_int16_t i;
129        char *p;
130
131        p = buf + len - 1;
132        i = num;
133	bzero(buf, len);
134        while (i) {
135                *--p = '0' + (i % 10);
136                i  /= 10;
137        }
138        return (p);
139}
140
141/*
142 * rcsnum_cpy()
143 *
144 * Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
145 * numbers deep.
146 * Returns 0 on success, or -1 on failure.
147 */
148int
149rcsnum_cpy(const RCSNUM *nsrc, RCSNUM *ndst, u_int depth)
150{
151	u_int len;
152	size_t sz;
153	void *tmp;
154
155	len = nsrc->rn_len;
156	if ((depth != 0) && (len > depth))
157		len = depth;
158	sz = len * sizeof(u_int16_t);
159
160	tmp = xrealloc(ndst->rn_id, sz);
161	ndst->rn_id = (u_int16_t *)tmp;
162	ndst->rn_len = len;
163	memcpy(ndst->rn_id, nsrc->rn_id, sz);
164	return (0);
165}
166
167/*
168 * rcsnum_cmp()
169 *
170 * Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
171 * <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
172 * The <depth> argument specifies how many numbers deep should be checked for
173 * the result.  A value of 0 means that the depth will be the minimum of the
174 * two numbers.
175 */
176int
177rcsnum_cmp(const RCSNUM *n1, const RCSNUM *n2, u_int depth)
178{
179	int res;
180	u_int i;
181	size_t slen;
182
183	slen = MIN(n1->rn_len, n2->rn_len);
184	if ((depth != 0) && (slen > depth))
185		slen = depth;
186
187	for (i = 0; i < slen; i++) {
188		res = n1->rn_id[i] - n2->rn_id[i];
189		if (res < 0)
190			return (1);
191		else if (res > 0)
192			return (-1);
193	}
194
195	if (n1->rn_len > n2->rn_len)
196		return (-1);
197	else if (n2->rn_len > n1->rn_len)
198		return (1);
199
200	return (0);
201}
202
203/*
204 * rcsnum_aton()
205 *
206 * Translate the string <str> containing a sequence of digits and periods into
207 * its binary representation, which is stored in <nump>.  The address of the
208 * first byte not part of the number is stored in <ep> on return, if it is not
209 * NULL.
210 * Returns 0 on success, or -1 on failure.
211 */
212int
213rcsnum_aton(const char *str, char **ep, RCSNUM *nump)
214{
215	u_int32_t val;
216	const char *sp;
217	void *tmp;
218	char *s;
219
220	if (nump->rn_id == NULL)
221		nump->rn_id = (u_int16_t *)xmalloc(sizeof(u_int16_t));
222
223	nump->rn_len = 0;
224	nump->rn_id[0] = 0;
225
226	for (sp = str;; sp++) {
227		if (!isdigit(*sp) && (*sp != '.'))
228			break;
229
230		if (*sp == '.') {
231			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
232				rcs_errno = RCS_ERR_BADNUM;
233				goto rcsnum_aton_failed;
234			}
235
236			nump->rn_len++;
237			tmp = xrealloc(nump->rn_id,
238			    (nump->rn_len + 1) * sizeof(u_int16_t));
239			nump->rn_id = (u_int16_t *)tmp;
240			nump->rn_id[nump->rn_len] = 0;
241			continue;
242		}
243
244		val = (nump->rn_id[nump->rn_len] * 10) + (*sp - 0x30);
245		if (val > RCSNUM_MAXNUM) {
246			cvs_log(LP_ERR, "RCSNUM overflow");
247			goto rcsnum_aton_failed;
248		}
249
250		nump->rn_id[nump->rn_len] = val;
251	}
252
253	if (ep != NULL)
254		*(const char **)ep = sp;
255
256	/*
257	 * Handle "magic" RCS branch numbers.
258	 *
259	 * What are they?
260	 *
261	 * Magic branch numbers have an extra .0. at the second farmost
262	 * rightside of the branch number, so instead of having an odd
263	 * number of dot-separated decimals, it will have an even number.
264	 *
265	 * Now, according to all the documentation i've found on the net
266	 * about this, cvs does this for "efficiency reasons", i'd like
267	 * to hear one.
268	 *
269	 * We just make sure we remove the .0. from in the branch number.
270	 *
271	 * XXX - for compatibility reasons with GNU cvs we _need_
272	 * to skip this part for the 'log' command, apparently it does
273	 * show the magic branches for an unknown and probably
274	 * completely insane and not understandable reason in that output.
275	 *
276	 */
277#if !defined(RCSPROG)
278	if ((nump->rn_len > 2) && (nump->rn_id[nump->rn_len - 1] == 0)
279	    && (cvs_cmdop != CVS_OP_LOG)) {
280#else
281	if ((nump->rn_len > 2) && (nump->rn_id[nump->rn_len - 1] == 0)) {
282#endif
283		/*
284		 * Look for ".0.x" at the end of the branch number.
285		 */
286		if ((s = strrchr(str, '.')) != NULL) {
287			*s--;
288			while (*s != '.')
289				*s--;
290
291			/*
292			 * If we have a "magic" branch, adjust it
293			 * so the .0. is removed.
294			 */
295			if (!strncmp(s, RCS_MAGIC_BRANCH,
296			    strlen(RCS_MAGIC_BRANCH))) {
297				nump->rn_id[nump->rn_len - 1] =
298				    nump->rn_id[nump->rn_len];
299				nump->rn_len--;
300			}
301		}
302	}
303
304	nump->rn_len++;
305	return (nump->rn_len);
306
307rcsnum_aton_failed:
308	nump->rn_len = 0;
309	xfree(nump->rn_id);
310	nump->rn_id = NULL;
311	return (-1);
312}
313
314/*
315 * rcsnum_inc()
316 *
317 * Increment the revision number specified in <num>.
318 * Returns a pointer to the <num> on success, or NULL on failure.
319 */
320RCSNUM *
321rcsnum_inc(RCSNUM *num)
322{
323	if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
324		return (NULL);
325	num->rn_id[num->rn_len - 1]++;
326	return (num);
327}
328
329/*
330 * rcsnum_dec()
331 *
332 * Decreases the revision number specified in <num>
333 * Returns pointer to the <num> on success, or NULL on failure.
334 */
335RCSNUM *
336rcsnum_dec(RCSNUM *num)
337{
338	if (num->rn_id[num->rn_len - 1] <= 0)
339		return (NULL);
340	num->rn_id[num->rn_len - 1]--;
341	return (num);
342}
343
344/*
345 * rcsnum_revtobr()
346 *
347 * Retrieve the branch number associated with the revision number <num>.
348 * If <num> is a branch revision, the returned value will be the same
349 * number as the argument.
350 */
351RCSNUM *
352rcsnum_revtobr(const RCSNUM *num)
353{
354	RCSNUM *brnum;
355
356	if (num->rn_len < 2)
357		return (NULL);
358
359	brnum = rcsnum_alloc();
360	rcsnum_cpy(num, brnum, 0);
361
362	if (!RCSNUM_ISBRANCH(brnum))
363		brnum->rn_len--;
364
365	return (brnum);
366}
367
368/*
369 * rcsnum_brtorev()
370 *
371 * Retrieve the initial revision number associated with the branch number <num>.
372 * If <num> is a revision number, an error will be returned.
373 */
374RCSNUM *
375rcsnum_brtorev(const RCSNUM *brnum)
376{
377	RCSNUM *num;
378
379	if (!RCSNUM_ISBRANCH(brnum)) {
380		return (NULL);
381	}
382
383	num = rcsnum_alloc();
384	if (rcsnum_setsize(num, brnum->rn_len + 1) < 0) {
385		rcsnum_free(num);
386		return (NULL);
387	}
388
389	rcsnum_cpy(brnum, num, brnum->rn_len);
390	num->rn_id[num->rn_len++] = 1;
391
392	return (num);
393}
394
395static int
396rcsnum_setsize(RCSNUM *num, u_int len)
397{
398	void *tmp;
399
400	tmp = xrealloc(num->rn_id, len * sizeof(u_int16_t));
401	num->rn_id = (u_int16_t *)tmp;
402	num->rn_len = len;
403	return (0);
404}
405