rcsnum.c revision 1.29 
1/*	$OpenBSD: rcsnum.c,v 1.29 2006/03/28 02:13:44 ray 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 on success,
42 * or NULL on failure.
43 */
44RCSNUM *
45rcsnum_alloc(void)
46{
47	RCSNUM *rnp;
48
49	rnp = (RCSNUM *)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.
145 * Returns 0 on success, or -1 on failure.
146 */
147int
148rcsnum_cpy(const RCSNUM *nsrc, RCSNUM *ndst, u_int depth)
149{
150	u_int len;
151	size_t sz;
152	void *tmp;
153
154	len = nsrc->rn_len;
155	if ((depth != 0) && (len > depth))
156		len = depth;
157	sz = len * sizeof(u_int16_t);
158
159	tmp = xrealloc(ndst->rn_id, 1, sz);
160	ndst->rn_id = (u_int16_t *)tmp;
161	ndst->rn_len = len;
162	memcpy(ndst->rn_id, nsrc->rn_id, sz);
163	return (0);
164}
165
166/*
167 * rcsnum_cmp()
168 *
169 * Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
170 * <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
171 * The <depth> argument specifies how many numbers deep should be checked for
172 * the result.  A value of 0 means that the depth will be the minimum of the
173 * two numbers.
174 */
175int
176rcsnum_cmp(const RCSNUM *n1, const RCSNUM *n2, u_int depth)
177{
178	int res;
179	u_int i;
180	size_t slen;
181
182	slen = MIN(n1->rn_len, n2->rn_len);
183	if ((depth != 0) && (slen > depth))
184		slen = depth;
185
186	for (i = 0; i < slen; i++) {
187		res = n1->rn_id[i] - n2->rn_id[i];
188		if (res < 0)
189			return (1);
190		else if (res > 0)
191			return (-1);
192	}
193
194	if (n1->rn_len > n2->rn_len)
195		return (-1);
196	else if (n2->rn_len > n1->rn_len)
197		return (1);
198
199	return (0);
200}
201
202/*
203 * rcsnum_aton()
204 *
205 * Translate the string <str> containing a sequence of digits and periods into
206 * its binary representation, which is stored in <nump>.  The address of the
207 * first byte not part of the number is stored in <ep> on return, if it is not
208 * NULL.
209 * Returns 0 on success, or -1 on failure.
210 */
211int
212rcsnum_aton(const char *str, char **ep, RCSNUM *nump)
213{
214	u_int32_t val;
215	const char *sp;
216	void *tmp;
217	char *s;
218
219	if (nump->rn_id == NULL)
220		nump->rn_id = (u_int16_t *)xmalloc(sizeof(u_int16_t));
221
222	nump->rn_len = 0;
223	nump->rn_id[0] = 0;
224
225	for (sp = str;; sp++) {
226		if (!isdigit(*sp) && (*sp != '.'))
227			break;
228
229		if (*sp == '.') {
230			if (nump->rn_len >= RCSNUM_MAXLEN - 1) {
231				rcs_errno = RCS_ERR_BADNUM;
232				goto rcsnum_aton_failed;
233			}
234
235			nump->rn_len++;
236			tmp = xrealloc(nump->rn_id,
237			    nump->rn_len + 1, sizeof(u_int16_t));
238			nump->rn_id = (u_int16_t *)tmp;
239			nump->rn_id[nump->rn_len] = 0;
240			continue;
241		}
242
243		val = (nump->rn_id[nump->rn_len] * 10) + (*sp - 0x30);
244		if (val > RCSNUM_MAXNUM)
245			fatal("RCSNUM overflow!");
246
247		nump->rn_id[nump->rn_len] = val;
248	}
249
250	if (ep != NULL)
251		*(const char **)ep = sp;
252
253	/*
254	 * Handle "magic" RCS branch numbers.
255	 *
256	 * What are they?
257	 *
258	 * Magic branch numbers have an extra .0. at the second farmost
259	 * rightside of the branch number, so instead of having an odd
260	 * number of dot-separated decimals, it will have an even number.
261	 *
262	 * Now, according to all the documentation i've found on the net
263	 * about this, cvs does this for "efficiency reasons", i'd like
264	 * to hear one.
265	 *
266	 * We just make sure we remove the .0. from in the branch number.
267	 *
268	 * XXX - for compatibility reasons with GNU cvs we _need_
269	 * to skip this part for the 'log' command, apparently it does
270	 * show the magic branches for an unknown and probably
271	 * completely insane and not understandable reason in that output.
272	 *
273	 */
274#if !defined(RCSPROG)
275	if ((nump->rn_len > 2) && (nump->rn_id[nump->rn_len - 1] == 0)
276	    && (cvs_cmdop != CVS_OP_LOG)) {
277#else
278	if ((nump->rn_len > 2) && (nump->rn_id[nump->rn_len - 1] == 0)) {
279#endif
280		/*
281		 * Look for ".0.x" at the end of the branch number.
282		 */
283		if ((s = strrchr(str, '.')) != NULL) {
284			s--;
285			while (*s != '.')
286				s--;
287
288			/*
289			 * If we have a "magic" branch, adjust it
290			 * so the .0. is removed.
291			 */
292			if (!strncmp(s, RCS_MAGIC_BRANCH,
293			    strlen(RCS_MAGIC_BRANCH))) {
294				nump->rn_id[nump->rn_len - 1] =
295				    nump->rn_id[nump->rn_len];
296				nump->rn_len--;
297			}
298		}
299	}
300
301	/* We can't have a single-digit rcs number. */
302	if (nump->rn_len == 0) {
303		tmp = xrealloc(nump->rn_id,
304		    nump->rn_len + 1, sizeof(u_int16_t));
305		nump->rn_id = (u_int16_t *)tmp;
306		nump->rn_id[nump->rn_len + 1] = 0;
307		nump->rn_len++;
308	}
309	nump->rn_len++;
310	return (nump->rn_len);
311
312rcsnum_aton_failed:
313	nump->rn_len = 0;
314	xfree(nump->rn_id);
315	nump->rn_id = NULL;
316	return (-1);
317}
318
319/*
320 * rcsnum_inc()
321 *
322 * Increment the revision number specified in <num>.
323 * Returns a pointer to the <num> on success, or NULL on failure.
324 */
325RCSNUM *
326rcsnum_inc(RCSNUM *num)
327{
328	if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
329		return (NULL);
330	num->rn_id[num->rn_len - 1]++;
331	return (num);
332}
333
334/*
335 * rcsnum_dec()
336 *
337 * Decreases the revision number specified in <num>, if doing so will not
338 * result in an ending value below 1. E.g. 4.2 will go to 4.1 but 4.1 will
339 * be returned as 4.1.
340 */
341RCSNUM *
342rcsnum_dec(RCSNUM *num)
343{
344	/* XXX - Is it an error for the number to be 0? */
345	if (num->rn_id[num->rn_len - 1] <= 1)
346		return (num);
347	num->rn_id[num->rn_len - 1]--;
348	return (num);
349}
350
351/*
352 * rcsnum_revtobr()
353 *
354 * Retrieve the branch number associated with the revision number <num>.
355 * If <num> is a branch revision, the returned value will be the same
356 * number as the argument.
357 */
358RCSNUM *
359rcsnum_revtobr(const RCSNUM *num)
360{
361	RCSNUM *brnum;
362
363	if (num->rn_len < 2)
364		return (NULL);
365
366	brnum = rcsnum_alloc();
367	rcsnum_cpy(num, brnum, 0);
368
369	if (!RCSNUM_ISBRANCH(brnum))
370		brnum->rn_len--;
371
372	return (brnum);
373}
374
375/*
376 * rcsnum_brtorev()
377 *
378 * Retrieve the initial revision number associated with the branch number <num>.
379 * If <num> is a revision number, an error will be returned.
380 */
381RCSNUM *
382rcsnum_brtorev(const RCSNUM *brnum)
383{
384	RCSNUM *num;
385
386	if (!RCSNUM_ISBRANCH(brnum)) {
387		return (NULL);
388	}
389
390	num = rcsnum_alloc();
391	if (rcsnum_setsize(num, brnum->rn_len + 1) < 0) {
392		rcsnum_free(num);
393		return (NULL);
394	}
395
396	rcsnum_cpy(brnum, num, brnum->rn_len);
397	num->rn_id[num->rn_len++] = 1;
398
399	return (num);
400}
401
402static int
403rcsnum_setsize(RCSNUM *num, u_int len)
404{
405	void *tmp;
406
407	tmp = xrealloc(num->rn_id, len, sizeof(u_int16_t));
408	num->rn_id = (u_int16_t *)tmp;
409	num->rn_len = len;
410	return (0);
411}
412