1 /*
2 * LibXDiff by Davide Libenzi ( File Differential Library )
3 * Copyright (C) 2003 Davide Libenzi
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, see
17 * <http://www.gnu.org/licenses/>.
18 *
19 * Davide Libenzi <davidel@xmailserver.org>
20 *
21 */
22
23 #include "xinclude.h"
24
25
26
27
xdl_bogosqrt(long n)28 long xdl_bogosqrt(long n) {
29 long i;
30
31 /*
32 * Classical integer square root approximation using shifts.
33 */
34 for (i = 1; n > 0; n >>= 2)
35 i <<= 1;
36
37 return i;
38 }
39
40
xdl_emit_diffrec(char const * rec,long size,char const * pre,long psize,xdemitcb_t * ecb)41 int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
42 xdemitcb_t *ecb) {
43 int i = 2;
44 mmbuffer_t mb[3];
45
46 mb[0].ptr = (char *) pre;
47 mb[0].size = psize;
48 mb[1].ptr = (char *) rec;
49 mb[1].size = size;
50 if (size > 0 && rec[size - 1] != '\n') {
51 mb[2].ptr = (char *) "\n\\ No newline at end of file\n";
52 mb[2].size = strlen(mb[2].ptr);
53 i++;
54 }
55 if (ecb->outf(ecb->priv, mb, i) < 0) {
56
57 return -1;
58 }
59
60 return 0;
61 }
62
xdl_mmfile_first(mmfile_t * mmf,long * size)63 void *xdl_mmfile_first(mmfile_t *mmf, long *size)
64 {
65 *size = mmf->size;
66 return mmf->ptr;
67 }
68
69
xdl_mmfile_size(mmfile_t * mmf)70 long xdl_mmfile_size(mmfile_t *mmf)
71 {
72 return mmf->size;
73 }
74
75
xdl_cha_init(chastore_t * cha,long isize,long icount)76 int xdl_cha_init(chastore_t *cha, long isize, long icount) {
77
78 cha->head = cha->tail = NULL;
79 cha->isize = isize;
80 cha->nsize = icount * isize;
81 cha->ancur = cha->sncur = NULL;
82 cha->scurr = 0;
83
84 return 0;
85 }
86
87
xdl_cha_free(chastore_t * cha)88 void xdl_cha_free(chastore_t *cha) {
89 chanode_t *cur, *tmp;
90
91 for (cur = cha->head; (tmp = cur) != NULL;) {
92 cur = cur->next;
93 xdl_free(tmp);
94 }
95 }
96
97
xdl_cha_alloc(chastore_t * cha)98 void *xdl_cha_alloc(chastore_t *cha) {
99 chanode_t *ancur;
100 void *data;
101
102 if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
103 if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
104
105 return NULL;
106 }
107 ancur->icurr = 0;
108 ancur->next = NULL;
109 if (cha->tail)
110 cha->tail->next = ancur;
111 if (!cha->head)
112 cha->head = ancur;
113 cha->tail = ancur;
114 cha->ancur = ancur;
115 }
116
117 data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
118 ancur->icurr += cha->isize;
119
120 return data;
121 }
122
xdl_guess_lines(mmfile_t * mf,long sample)123 long xdl_guess_lines(mmfile_t *mf, long sample) {
124 long nl = 0, size, tsize = 0;
125 char const *data, *cur, *top;
126
127 if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
128 for (top = data + size; nl < sample && cur < top; ) {
129 nl++;
130 if (!(cur = memchr(cur, '\n', top - cur)))
131 cur = top;
132 else
133 cur++;
134 }
135 tsize += (long) (cur - data);
136 }
137
138 if (nl && tsize)
139 nl = xdl_mmfile_size(mf) / (tsize / nl);
140
141 return nl + 1;
142 }
143
xdl_blankline(const char * line,long size,long flags)144 int xdl_blankline(const char *line, long size, long flags)
145 {
146 long i;
147
148 if (!(flags & XDF_WHITESPACE_FLAGS))
149 return (size <= 1);
150
151 for (i = 0; i < size && XDL_ISSPACE(line[i]); i++)
152 ;
153
154 return (i == size);
155 }
156
157 /*
158 * Have we eaten everything on the line, except for an optional
159 * CR at the very end?
160 */
ends_with_optional_cr(const char * l,long s,long i)161 static int ends_with_optional_cr(const char *l, long s, long i)
162 {
163 int complete = s && l[s-1] == '\n';
164
165 if (complete)
166 s--;
167 if (s == i)
168 return 1;
169 /* do not ignore CR at the end of an incomplete line */
170 if (complete && s == i + 1 && l[i] == '\r')
171 return 1;
172 return 0;
173 }
174
xdl_recmatch(const char * l1,long s1,const char * l2,long s2,long flags)175 int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
176 {
177 int i1, i2;
178
179 if (s1 == s2 && !memcmp(l1, l2, s1))
180 return 1;
181 if (!(flags & XDF_WHITESPACE_FLAGS))
182 return 0;
183
184 i1 = 0;
185 i2 = 0;
186
187 /*
188 * -w matches everything that matches with -b, and -b in turn
189 * matches everything that matches with --ignore-space-at-eol,
190 * which in turn matches everything that matches with --ignore-cr-at-eol.
191 *
192 * Each flavor of ignoring needs different logic to skip whitespaces
193 * while we have both sides to compare.
194 */
195 if (flags & XDF_IGNORE_WHITESPACE) {
196 goto skip_ws;
197 while (i1 < s1 && i2 < s2) {
198 if (l1[i1++] != l2[i2++])
199 return 0;
200 skip_ws:
201 while (i1 < s1 && XDL_ISSPACE(l1[i1]))
202 i1++;
203 while (i2 < s2 && XDL_ISSPACE(l2[i2]))
204 i2++;
205 }
206 } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
207 while (i1 < s1 && i2 < s2) {
208 if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
209 /* Skip matching spaces and try again */
210 while (i1 < s1 && XDL_ISSPACE(l1[i1]))
211 i1++;
212 while (i2 < s2 && XDL_ISSPACE(l2[i2]))
213 i2++;
214 continue;
215 }
216 if (l1[i1++] != l2[i2++])
217 return 0;
218 }
219 } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
220 while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
221 i1++;
222 i2++;
223 }
224 } else if (flags & XDF_IGNORE_CR_AT_EOL) {
225 /* Find the first difference and see how the line ends */
226 while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
227 i1++;
228 i2++;
229 }
230 return (ends_with_optional_cr(l1, s1, i1) &&
231 ends_with_optional_cr(l2, s2, i2));
232 }
233
234 /*
235 * After running out of one side, the remaining side must have
236 * nothing but whitespace for the lines to match. Note that
237 * ignore-whitespace-at-eol case may break out of the loop
238 * while there still are characters remaining on both lines.
239 */
240 if (i1 < s1) {
241 while (i1 < s1 && XDL_ISSPACE(l1[i1]))
242 i1++;
243 if (s1 != i1)
244 return 0;
245 }
246 if (i2 < s2) {
247 while (i2 < s2 && XDL_ISSPACE(l2[i2]))
248 i2++;
249 return (s2 == i2);
250 }
251 return 1;
252 }
253
xdl_hash_record_with_whitespace(char const ** data,char const * top,long flags)254 static unsigned long xdl_hash_record_with_whitespace(char const **data,
255 char const *top, long flags) {
256 unsigned long ha = 5381;
257 char const *ptr = *data;
258 int cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL;
259
260 for (; ptr < top && *ptr != '\n'; ptr++) {
261 if (cr_at_eol_only) {
262 /* do not ignore CR at the end of an incomplete line */
263 if (*ptr == '\r' &&
264 (ptr + 1 < top && ptr[1] == '\n'))
265 continue;
266 }
267 else if (XDL_ISSPACE(*ptr)) {
268 const char *ptr2 = ptr;
269 int at_eol;
270 while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
271 && ptr[1] != '\n')
272 ptr++;
273 at_eol = (top <= ptr + 1 || ptr[1] == '\n');
274 if (flags & XDF_IGNORE_WHITESPACE)
275 ; /* already handled */
276 else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
277 && !at_eol) {
278 ha += (ha << 5);
279 ha ^= (unsigned long) ' ';
280 }
281 else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
282 && !at_eol) {
283 while (ptr2 != ptr + 1) {
284 ha += (ha << 5);
285 ha ^= (unsigned long) *ptr2;
286 ptr2++;
287 }
288 }
289 continue;
290 }
291 ha += (ha << 5);
292 ha ^= (unsigned long) *ptr;
293 }
294 *data = ptr < top ? ptr + 1: ptr;
295
296 return ha;
297 }
298
xdl_hash_record(char const ** data,char const * top,long flags)299 unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
300 unsigned long ha = 5381;
301 char const *ptr = *data;
302
303 if (flags & XDF_WHITESPACE_FLAGS)
304 return xdl_hash_record_with_whitespace(data, top, flags);
305
306 for (; ptr < top && *ptr != '\n'; ptr++) {
307 ha += (ha << 5);
308 ha ^= (unsigned long) *ptr;
309 }
310 *data = ptr < top ? ptr + 1: ptr;
311
312 return ha;
313 }
314
xdl_hashbits(unsigned int size)315 unsigned int xdl_hashbits(unsigned int size) {
316 unsigned int val = 1, bits = 0;
317
318 for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
319 return bits ? bits: 1;
320 }
321
322
xdl_num_out(char * out,long val)323 int xdl_num_out(char *out, long val) {
324 char *ptr, *str = out;
325 char buf[32];
326
327 ptr = buf + sizeof(buf) - 1;
328 *ptr = '\0';
329 if (val < 0) {
330 *--ptr = '-';
331 val = -val;
332 }
333 for (; val && ptr > buf; val /= 10)
334 *--ptr = "0123456789"[val % 10];
335 if (*ptr)
336 for (; *ptr; ptr++, str++)
337 *str = *ptr;
338 else
339 *str++ = '0';
340 *str = '\0';
341
342 return str - out;
343 }
344
xdl_emit_hunk_hdr(long s1,long c1,long s2,long c2,const char * func,long funclen,xdemitcb_t * ecb)345 int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
346 const char *func, long funclen, xdemitcb_t *ecb) {
347 int nb = 0;
348 mmbuffer_t mb;
349 char buf[128];
350
351 memcpy(buf, "@@ -", 4);
352 nb += 4;
353
354 nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
355
356 if (c1 != 1) {
357 memcpy(buf + nb, ",", 1);
358 nb += 1;
359
360 nb += xdl_num_out(buf + nb, c1);
361 }
362
363 memcpy(buf + nb, " +", 2);
364 nb += 2;
365
366 nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
367
368 if (c2 != 1) {
369 memcpy(buf + nb, ",", 1);
370 nb += 1;
371
372 nb += xdl_num_out(buf + nb, c2);
373 }
374
375 memcpy(buf + nb, " @@", 3);
376 nb += 3;
377 if (func && funclen) {
378 buf[nb++] = ' ';
379 if (funclen > (long)(sizeof(buf) - nb - 1))
380 funclen = sizeof(buf) - nb - 1;
381 memcpy(buf + nb, func, funclen);
382 nb += funclen;
383 }
384 buf[nb++] = '\n';
385
386 mb.ptr = buf;
387 mb.size = nb;
388 if (ecb->outf(ecb->priv, &mb, 1) < 0)
389 return -1;
390
391 return 0;
392 }
393
xdl_fall_back_diff(xdfenv_t * diff_env,xpparam_t const * xpp,int line1,int count1,int line2,int count2)394 int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
395 int line1, int count1, int line2, int count2)
396 {
397 /*
398 * This probably does not work outside Git, since
399 * we have a very simple mmfile structure.
400 *
401 * Note: ideally, we would reuse the prepared environment, but
402 * the libxdiff interface does not (yet) allow for diffing only
403 * ranges of lines instead of the whole files.
404 */
405 mmfile_t subfile1, subfile2;
406 xdfenv_t env;
407
408 subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
409 subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
410 diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
411 subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
412 subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
413 diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
414 if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
415 return -1;
416
417 memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
418 memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);
419
420 xdl_free_env(&env);
421
422 return 0;
423 }
424