2 * LibXDiff by Davide Libenzi ( File Differential Library )
3 * Copyright (C) 2003-2006 Davide Libenzi, Johannes E. Schindelin
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.
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.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Davide Libenzi <davidel@xmailserver.org>
25 typedef struct s_xdmerge {
26 struct s_xdmerge *next;
29 * 1 = no conflict, take first,
30 * 2 = no conflict, take second.
34 * These point at the respective postimages. E.g. <i1,chg1> is
35 * how side #1 wants to change the common ancestor; if there is no
36 * overlap, lines before i1 in the postimage of side #1 appear
37 * in the merge result as a region touched by neither side.
42 * These point at the preimage; of course there is just one
43 * preimage, that is from the shared common ancestor.
49 static int xdl_append_merge(xdmerge_t **merge, int mode,
54 xdmerge_t *m = *merge;
55 if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
58 m->chg0 = i0 + chg0 - m->i0;
59 m->chg1 = i1 + chg1 - m->i1;
60 m->chg2 = i2 + chg2 - m->i2;
62 m = xdl_malloc(sizeof(xdmerge_t));
80 static int xdl_cleanup_merge(xdmerge_t *c)
85 /* were there conflicts? */
86 for (; c; c = next_c) {
95 static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
96 int line_count, long flags)
99 xrecord_t **rec1 = xe1->xdf2.recs + i1;
100 xrecord_t **rec2 = xe2->xdf2.recs + i2;
102 for (i = 0; i < line_count; i++) {
103 int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
104 rec2[i]->ptr, rec2[i]->size, flags);
111 static int xdl_recs_copy_0(int use_orig, xdfenv_t *xe, int i, int count, int add_nl, char *dest)
116 recs = (use_orig ? xe->xdf1.recs : xe->xdf2.recs) + i;
121 for (i = 0; i < count; size += recs[i++]->size)
123 memcpy(dest + size, recs[i]->ptr, recs[i]->size);
125 i = recs[count - 1]->size;
126 if (i == 0 || recs[count - 1]->ptr[i - 1] != '\n') {
135 static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
137 return xdl_recs_copy_0(0, xe, i, count, add_nl, dest);
140 static int xdl_orig_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
142 return xdl_recs_copy_0(1, xe, i, count, add_nl, dest);
145 static int fill_conflict_hunk(xdfenv_t *xe1, const char *name1,
146 xdfenv_t *xe2, const char *name2,
147 int size, int i, int style,
148 xdmerge_t *m, char *dest, int marker_size)
150 int marker1_size = (name1 ? strlen(name1) + 1 : 0);
151 int marker2_size = (name2 ? strlen(name2) + 1 : 0);
154 if (marker_size <= 0)
155 marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
157 /* Before conflicting part */
158 size += xdl_recs_copy(xe1, i, m->i1 - i, 0,
159 dest ? dest + size : NULL);
162 size += marker_size + 1 + marker1_size;
164 for (j = 0; j < marker_size; j++)
168 memcpy(dest + size + 1, name1, marker1_size - 1);
169 size += marker1_size;
174 /* Postimage from side #1 */
175 size += xdl_recs_copy(xe1, m->i1, m->chg1, 1,
176 dest ? dest + size : NULL);
178 if (style == XDL_MERGE_DIFF3) {
179 /* Shared preimage */
181 size += marker_size + 1;
183 for (j = 0; j < marker_size; j++)
187 size += xdl_orig_copy(xe1, m->i0, m->chg0, 1,
188 dest ? dest + size : NULL);
192 size += marker_size + 1;
194 for (j = 0; j < marker_size; j++)
199 /* Postimage from side #2 */
200 size += xdl_recs_copy(xe2, m->i2, m->chg2, 1,
201 dest ? dest + size : NULL);
203 size += marker_size + 1 + marker2_size;
205 for (j = 0; j < marker_size; j++)
209 memcpy(dest + size + 1, name2, marker2_size - 1);
210 size += marker2_size;
217 static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
218 xdfenv_t *xe2, const char *name2,
219 xdmerge_t *m, char *dest, int style,
224 for (size = i = 0; m; m = m->next) {
226 size = fill_conflict_hunk(xe1, name1, xe2, name2,
227 size, i, style, m, dest,
229 else if (m->mode == 1)
230 size += xdl_recs_copy(xe1, i, m->i1 + m->chg1 - i, 0,
231 dest ? dest + size : NULL);
232 else if (m->mode == 2)
233 size += xdl_recs_copy(xe2, m->i2 - m->i1 + i,
234 m->i1 + m->chg2 - i, 0,
235 dest ? dest + size : NULL);
240 size += xdl_recs_copy(xe1, i, xe1->xdf2.nrec - i, 0,
241 dest ? dest + size : NULL);
246 * Sometimes, changes are not quite identical, but differ in only a few
247 * lines. Try hard to show only these few lines as conflicting.
249 static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
250 xpparam_t const *xpp)
252 for (; m; m = m->next) {
255 xdchange_t *xscr, *x;
256 int i1 = m->i1, i2 = m->i2;
258 /* let's handle just the conflicts */
262 /* no sense refining a conflict when one side is empty */
263 if (m->chg1 == 0 || m->chg2 == 0)
267 * This probably does not work outside git, since
268 * we have a very simple mmfile structure.
270 t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
271 t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
272 + xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
273 t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
274 t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
275 + xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
276 if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
278 if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
279 xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
280 xdl_build_script(&xe, &xscr) < 0) {
285 /* If this happens, the changes are identical. */
291 m->i1 = xscr->i1 + i1;
292 m->chg1 = xscr->chg1;
293 m->i2 = xscr->i2 + i2;
294 m->chg2 = xscr->chg2;
296 xdmerge_t *m2 = xdl_malloc(sizeof(xdmerge_t));
307 m->i1 = xscr->i1 + i1;
308 m->chg1 = xscr->chg1;
309 m->i2 = xscr->i2 + i2;
310 m->chg2 = xscr->chg2;
318 static int line_contains_alnum(const char *ptr, long size)
321 if (isalnum(*(ptr++)))
326 static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
328 for (; chg; chg--, i++)
329 if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
330 xe->xdf2.recs[i]->size))
336 * This function merges m and m->next, marking everything between those hunks
337 * as conflicting, too.
339 static void xdl_merge_two_conflicts(xdmerge_t *m)
341 xdmerge_t *next_m = m->next;
342 m->chg1 = next_m->i1 + next_m->chg1 - m->i1;
343 m->chg2 = next_m->i2 + next_m->chg2 - m->i2;
344 m->next = next_m->next;
349 * If there are less than 3 non-conflicting lines between conflicts,
350 * it appears simpler -- because it takes up less (or as many) lines --
351 * if the lines are moved into the conflicts.
353 static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
354 int simplify_if_no_alnum)
361 xdmerge_t *next_m = m->next;
367 begin = m->i1 + m->chg1;
370 if (m->mode != 0 || next_m->mode != 0 ||
372 (!simplify_if_no_alnum ||
373 lines_contain_alnum(xe1, begin, end - begin)))) {
377 xdl_merge_two_conflicts(m);
383 * level == 0: mark all overlapping changes as conflict
384 * level == 1: mark overlapping changes as conflict only if not identical
385 * level == 2: analyze non-identical changes for minimal conflict set
386 * level == 3: analyze non-identical changes for minimal conflict set, but
387 * treat hunks not containing any letter or number as conflicting
389 * returns < 0 on error, == 0 for no conflicts, else number of conflicts
391 static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
392 xdfenv_t *xe2, xdchange_t *xscr2, const char *name2,
393 int flags, xmparam_t const *xmp, mmbuffer_t *result) {
394 xdmerge_t *changes, *c;
395 xpparam_t const *xpp = &xmp->xpp;
396 int i0, i1, i2, chg0, chg1, chg2;
397 int level = flags & XDL_MERGE_LEVEL_MASK;
398 int style = flags & XDL_MERGE_STYLE_MASK;
400 if (style == XDL_MERGE_DIFF3) {
402 * "diff3 -m" output does not make sense for anything
403 * more aggressive than XDL_MERGE_EAGER.
405 if (XDL_MERGE_EAGER < level)
406 level = XDL_MERGE_EAGER;
411 while (xscr1 && xscr2) {
414 if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
417 i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
421 if (xdl_append_merge(&c, 1,
422 i0, chg0, i1, chg1, i2, chg2)) {
423 xdl_cleanup_merge(changes);
429 if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
431 i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
436 if (xdl_append_merge(&c, 2,
437 i0, chg0, i1, chg1, i2, chg2)) {
438 xdl_cleanup_merge(changes);
444 if (level == XDL_MERGE_MINIMAL || xscr1->i1 != xscr2->i1 ||
445 xscr1->chg1 != xscr2->chg1 ||
446 xscr1->chg2 != xscr2->chg2 ||
447 xdl_merge_cmp_lines(xe1, xscr1->i2,
449 xscr1->chg2, xpp->flags)) {
451 int off = xscr1->i1 - xscr2->i1;
452 int ffo = off + xscr1->chg1 - xscr2->chg1;
463 chg0 = xscr1->i1 + xscr1->chg1 - i0;
464 chg1 = xscr1->i2 + xscr1->chg2 - i1;
465 chg2 = xscr2->i2 + xscr2->chg2 - i2;
471 if (xdl_append_merge(&c, 0,
472 i0, chg0, i1, chg1, i2, chg2)) {
473 xdl_cleanup_merge(changes);
478 i1 = xscr1->i1 + xscr1->chg1;
479 i2 = xscr2->i1 + xscr2->chg1;
491 i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
495 if (xdl_append_merge(&c, 1,
496 i0, chg0, i1, chg1, i2, chg2)) {
497 xdl_cleanup_merge(changes);
506 i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
511 if (xdl_append_merge(&c, 2,
512 i0, chg0, i1, chg1, i2, chg2)) {
513 xdl_cleanup_merge(changes);
520 /* refine conflicts */
521 if (XDL_MERGE_ZEALOUS <= level &&
522 (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
523 xdl_simplify_non_conflicts(xe1, changes,
524 XDL_MERGE_ZEALOUS < level) < 0)) {
525 xdl_cleanup_merge(changes);
530 int marker_size = xmp->marker_size;
531 int size = xdl_fill_merge_buffer(xe1, name1, xe2, name2,
532 changes, NULL, style,
534 result->ptr = xdl_malloc(size);
536 xdl_cleanup_merge(changes);
540 xdl_fill_merge_buffer(xe1, name1, xe2, name2, changes,
541 result->ptr, style, marker_size);
543 return xdl_cleanup_merge(changes);
546 int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
547 mmfile_t *mf2, const char *name2,
548 xmparam_t const *xmp, int flags, mmbuffer_t *result) {
549 xdchange_t *xscr1, *xscr2;
552 xpparam_t const *xpp = &xmp->xpp;
557 if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0 ||
558 xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
561 if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
562 xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
563 xdl_build_script(&xe1, &xscr1) < 0) {
567 if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
568 xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
569 xdl_build_script(&xe2, &xscr2) < 0) {
575 result->ptr = xdl_malloc(mf2->size);
576 memcpy(result->ptr, mf2->ptr, mf2->size);
577 result->size = mf2->size;
579 result->ptr = xdl_malloc(mf1->size);
580 memcpy(result->ptr, mf1->ptr, mf1->size);
581 result->size = mf1->size;
583 status = xdl_do_merge(&xe1, xscr1, name1,
587 xdl_free_script(xscr1);
588 xdl_free_script(xscr2);