Don't fflush(stdout) when it's not helpful
[git/git.git] / diffcore-rename.c
CommitLineData
427dcb4b
JH
1/*
2 * Copyright (C) 2005 Junio C Hamano
3 */
4#include "cache.h"
5#include "diff.h"
6#include "diffcore.h"
427dcb4b 7
25d5ea41
JH
8/* Table of rename/copy destinations */
9
10static struct diff_rename_dst {
11 struct diff_filespec *two;
12 struct diff_filepair *pair;
13} *rename_dst;
14static int rename_dst_nr, rename_dst_alloc;
427dcb4b 15
25d5ea41
JH
16static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
17 int insert_ok)
427dcb4b 18{
25d5ea41
JH
19 int first, last;
20
21 first = 0;
22 last = rename_dst_nr;
23 while (last > first) {
24 int next = (last + first) >> 1;
25 struct diff_rename_dst *dst = &(rename_dst[next]);
26 int cmp = strcmp(two->path, dst->two->path);
27 if (!cmp)
28 return dst;
29 if (cmp < 0) {
30 last = next;
31 continue;
32 }
33 first = next+1;
34 }
35 /* not found */
36 if (!insert_ok)
37 return NULL;
38 /* insert to make it at "first" */
39 if (rename_dst_alloc <= rename_dst_nr) {
40 rename_dst_alloc = alloc_nr(rename_dst_alloc);
41 rename_dst = xrealloc(rename_dst,
42 rename_dst_alloc * sizeof(*rename_dst));
43 }
44 rename_dst_nr++;
45 if (first < rename_dst_nr)
46 memmove(rename_dst + first + 1, rename_dst + first,
47 (rename_dst_nr - first - 1) * sizeof(*rename_dst));
5098bafb
JH
48 rename_dst[first].two = alloc_filespec(two->path);
49 fill_filespec(rename_dst[first].two, two->sha1, two->mode);
25d5ea41
JH
50 rename_dst[first].pair = NULL;
51 return &(rename_dst[first]);
427dcb4b
JH
52}
53
15d061b4 54/* Table of rename/copy src files */
25d5ea41
JH
55static struct diff_rename_src {
56 struct diff_filespec *one;
fc580719 57 unsigned short score; /* to remember the break score */
6bac10d8 58 unsigned src_path_left : 1;
25d5ea41
JH
59} *rename_src;
60static int rename_src_nr, rename_src_alloc;
427dcb4b 61
15d061b4 62static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
fc580719
JH
63 int src_path_left,
64 unsigned short score)
25d5ea41
JH
65{
66 int first, last;
67
68 first = 0;
69 last = rename_src_nr;
70 while (last > first) {
71 int next = (last + first) >> 1;
72 struct diff_rename_src *src = &(rename_src[next]);
73 int cmp = strcmp(one->path, src->one->path);
74 if (!cmp)
75 return src;
76 if (cmp < 0) {
77 last = next;
78 continue;
79 }
80 first = next+1;
81 }
15d061b4 82
25d5ea41
JH
83 /* insert to make it at "first" */
84 if (rename_src_alloc <= rename_src_nr) {
85 rename_src_alloc = alloc_nr(rename_src_alloc);
86 rename_src = xrealloc(rename_src,
87 rename_src_alloc * sizeof(*rename_src));
427dcb4b 88 }
25d5ea41
JH
89 rename_src_nr++;
90 if (first < rename_src_nr)
91 memmove(rename_src + first + 1, rename_src + first,
92 (rename_src_nr - first - 1) * sizeof(*rename_src));
93 rename_src[first].one = one;
fc580719 94 rename_src[first].score = score;
6bac10d8 95 rename_src[first].src_path_left = src_path_left;
25d5ea41 96 return &(rename_src[first]);
427dcb4b
JH
97}
98
17e6019a
JH
99static int is_exact_match(struct diff_filespec *src,
100 struct diff_filespec *dst,
101 int contents_too)
427dcb4b
JH
102{
103 if (src->sha1_valid && dst->sha1_valid &&
a89fccd2 104 !hashcmp(src->sha1, dst->sha1))
427dcb4b 105 return 1;
17e6019a
JH
106 if (!contents_too)
107 return 0;
f0c6b2a2
JH
108 if (diff_populate_filespec(src, 1) || diff_populate_filespec(dst, 1))
109 return 0;
110 if (src->size != dst->size)
111 return 0;
7da41f48
SP
112 if (src->sha1_valid && dst->sha1_valid)
113 return !hashcmp(src->sha1, dst->sha1);
f0c6b2a2 114 if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
427dcb4b
JH
115 return 0;
116 if (src->size == dst->size &&
117 !memcmp(src->data, dst->data, src->size))
118 return 1;
119 return 0;
120}
121
0ce39643
JS
122static int basename_same(struct diff_filespec *src, struct diff_filespec *dst)
123{
124 int src_len = strlen(src->path), dst_len = strlen(dst->path);
125 while (src_len && dst_len) {
126 char c1 = src->path[--src_len];
127 char c2 = dst->path[--dst_len];
128 if (c1 != c2)
129 return 0;
130 if (c1 == '/')
131 return 1;
132 }
133 return (!src_len || src->path[src_len - 1] == '/') &&
134 (!dst_len || dst->path[dst_len - 1] == '/');
135}
136
427dcb4b 137struct diff_score {
25d5ea41
JH
138 int src; /* index in rename_src */
139 int dst; /* index in rename_dst */
427dcb4b 140 int score;
427dcb4b
JH
141};
142
143static int estimate_similarity(struct diff_filespec *src,
144 struct diff_filespec *dst,
145 int minimum_score)
146{
147 /* src points at a file that existed in the original tree (or
148 * optionally a file in the destination tree) and dst points
149 * at a newly created file. They may be quite similar, in which
150 * case we want to say src is renamed to dst or src is copied into
151 * dst, and then some edit has been applied to dst.
152 *
153 * Compare them and return how similar they are, representing
f0c6b2a2
JH
154 * the score as an integer between 0 and MAX_SCORE.
155 *
156 * When there is an exact match, it is considered a better
157 * match than anything else; the destination does not even
158 * call into this function in that case.
427dcb4b 159 */
90bd932c 160 unsigned long max_size, delta_size, base_size, src_copied, literal_added;
75c660ac 161 unsigned long delta_limit;
427dcb4b
JH
162 int score;
163
60896c7b
JH
164 /* We deal only with regular files. Symlink renames are handled
165 * only when they are exact matches --- in other words, no edits
166 * after renaming.
167 */
168 if (!S_ISREG(src->mode) || !S_ISREG(dst->mode))
169 return 0;
170
90bd932c 171 max_size = ((src->size > dst->size) ? src->size : dst->size);
58b103f5 172 base_size = ((src->size < dst->size) ? src->size : dst->size);
90bd932c 173 delta_size = max_size - base_size;
427dcb4b 174
58b103f5
JH
175 /* We would not consider edits that change the file size so
176 * drastically. delta_size must be smaller than
cd1870ed 177 * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
f0c6b2a2 178 *
58b103f5
JH
179 * Note that base_size == 0 case is handled here already
180 * and the final score computation below would not have a
181 * divide-by-zero issue.
427dcb4b 182 */
cd1870ed 183 if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
427dcb4b
JH
184 return 0;
185
f0c6b2a2
JH
186 if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
187 return 0; /* error but caught downstream */
188
85976974 189
dc49cd76
SP
190 delta_limit = (unsigned long)
191 (base_size * (MAX_SCORE-minimum_score) / MAX_SCORE);
65416758
JH
192 if (diffcore_count_changes(src->data, src->size,
193 dst->data, dst->size,
c06c7966 194 &src->cnt_data, &dst->cnt_data,
65416758
JH
195 delta_limit,
196 &src_copied, &literal_added))
85976974 197 return 0;
355e76a4 198
1706306a
JH
199 /* How similar are they?
200 * what percentage of material in dst are from source?
427dcb4b 201 */
90bd932c 202 if (!dst->size)
1706306a 203 score = 0; /* should not happen */
0ce39643 204 else {
dc49cd76 205 score = (int)(src_copied * MAX_SCORE / max_size);
0ce39643
JS
206 if (basename_same(src, dst))
207 score++;
208 }
427dcb4b
JH
209 return score;
210}
211
5098bafb 212static void record_rename_pair(int dst_index, int src_index, int score)
427dcb4b 213{
25d5ea41
JH
214 struct diff_filespec *one, *two, *src, *dst;
215 struct diff_filepair *dp;
f7c1512a 216
25d5ea41
JH
217 if (rename_dst[dst_index].pair)
218 die("internal error: dst already matched.");
427dcb4b 219
25d5ea41
JH
220 src = rename_src[src_index].one;
221 one = alloc_filespec(src->path);
222 fill_filespec(one, src->sha1, src->mode);
427dcb4b 223
25d5ea41
JH
224 dst = rename_dst[dst_index].two;
225 two = alloc_filespec(dst->path);
226 fill_filespec(two, dst->sha1, dst->mode);
427dcb4b 227
5098bafb 228 dp = diff_queue(NULL, one, two);
ef677686 229 dp->renamed_pair = 1;
fc580719
JH
230 if (!strcmp(src->path, dst->path))
231 dp->score = rename_src[src_index].score;
232 else
233 dp->score = score;
6bac10d8 234 dp->source_stays = rename_src[src_index].src_path_left;
25d5ea41 235 rename_dst[dst_index].pair = dp;
427dcb4b
JH
236}
237
238/*
239 * We sort the rename similarity matrix with the score, in descending
15d061b4 240 * order (the most similar first).
427dcb4b
JH
241 */
242static int score_compare(const void *a_, const void *b_)
243{
244 const struct diff_score *a = a_, *b = b_;
245 return b->score - a->score;
246}
247
6bac10d8
JH
248static int compute_stays(struct diff_queue_struct *q,
249 struct diff_filespec *one)
250{
251 int i;
252 for (i = 0; i < q->nr; i++) {
253 struct diff_filepair *p = q->queue[i];
254 if (strcmp(one->path, p->two->path))
255 continue;
256 if (DIFF_PAIR_RENAME(p)) {
257 return 0; /* something else is renamed into this */
258 }
259 }
260 return 1;
261}
262
8082d8d3 263void diffcore_rename(struct diff_options *options)
427dcb4b 264{
8082d8d3
JH
265 int detect_rename = options->detect_rename;
266 int minimum_score = options->rename_score;
267 int rename_limit = options->rename_limit;
38c6f780 268 struct diff_queue_struct *q = &diff_queued_diff;
5098bafb 269 struct diff_queue_struct outq;
427dcb4b 270 struct diff_score *mx;
17e6019a 271 int i, j, rename_count, contents_too;
25d5ea41 272 int num_create, num_src, dst_cnt;
427dcb4b 273
26dee0ad 274 if (!minimum_score)
f345b0a0 275 minimum_score = DEFAULT_RENAME_SCORE;
5098bafb 276 rename_count = 0;
427dcb4b 277
427dcb4b 278 for (i = 0; i < q->nr; i++) {
52e95789 279 struct diff_filepair *p = q->queue[i];
2f3f8b21 280 if (!DIFF_FILE_VALID(p->one)) {
81e50eab 281 if (!DIFF_FILE_VALID(p->two))
60896c7b 282 continue; /* unmerged */
2f3f8b21
JH
283 else if (options->single_follow &&
284 strcmp(options->single_follow, p->two->path))
285 continue; /* not interested */
427dcb4b 286 else
25d5ea41 287 locate_rename_dst(p->two, 1);
2f3f8b21 288 }
2210100a
JH
289 else if (!DIFF_FILE_VALID(p->two)) {
290 /* If the source is a broken "delete", and
291 * they did not really want to get broken,
292 * that means the source actually stays.
293 */
294 int stays = (p->broken_pair && !p->score);
fc580719 295 register_rename_src(p->one, stays, p->score);
2210100a 296 }
15d061b4 297 else if (detect_rename == DIFF_DETECT_COPY)
fc580719 298 register_rename_src(p->one, 1, p->score);
427dcb4b 299 }
7d6fb370 300 if (rename_dst_nr == 0 || rename_src_nr == 0 ||
3299c6f6 301 (0 < rename_limit && rename_limit < rename_dst_nr))
427dcb4b
JH
302 goto cleanup; /* nothing to do */
303
304 /* We really want to cull the candidates list early
305 * with cheap tests in order to avoid doing deltas.
17e6019a
JH
306 * The first round matches up the up-to-date entries,
307 * and then during the second round we try to match
308 * cache-dirty entries as well.
427dcb4b 309 */
17e6019a
JH
310 for (contents_too = 0; contents_too < 2; contents_too++) {
311 for (i = 0; i < rename_dst_nr; i++) {
312 struct diff_filespec *two = rename_dst[i].two;
313 if (rename_dst[i].pair)
314 continue; /* dealt with an earlier round */
315 for (j = 0; j < rename_src_nr; j++) {
0ce39643 316 int k;
17e6019a
JH
317 struct diff_filespec *one = rename_src[j].one;
318 if (!is_exact_match(one, two, contents_too))
319 continue;
0ce39643
JS
320
321 /* see if there is a basename match, too */
322 for (k = j; k < rename_src_nr; k++) {
323 one = rename_src[k].one;
324 if (basename_same(one, two) &&
325 is_exact_match(one, two,
326 contents_too)) {
327 j = k;
328 break;
329 }
330 }
331
dc49cd76 332 record_rename_pair(i, j, (int)MAX_SCORE);
17e6019a
JH
333 rename_count++;
334 break; /* we are done with this entry */
335 }
427dcb4b
JH
336 }
337 }
427dcb4b
JH
338
339 /* Have we run out the created file pool? If so we can avoid
340 * doing the delta matrix altogether.
341 */
5098bafb 342 if (rename_count == rename_dst_nr)
15d061b4 343 goto cleanup;
427dcb4b 344
9f70b806
JH
345 if (minimum_score == MAX_SCORE)
346 goto cleanup;
347
5098bafb 348 num_create = (rename_dst_nr - rename_count);
25d5ea41 349 num_src = rename_src_nr;
427dcb4b 350 mx = xmalloc(sizeof(*mx) * num_create * num_src);
25d5ea41 351 for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
427dcb4b 352 int base = dst_cnt * num_src;
25d5ea41
JH
353 struct diff_filespec *two = rename_dst[i].two;
354 if (rename_dst[i].pair)
427dcb4b 355 continue; /* dealt with exact match already. */
25d5ea41
JH
356 for (j = 0; j < rename_src_nr; j++) {
357 struct diff_filespec *one = rename_src[j].one;
358 struct diff_score *m = &mx[base+j];
359 m->src = j;
360 m->dst = i;
361 m->score = estimate_similarity(one, two,
362 minimum_score);
50b2b538 363 diff_free_filespec_data(one);
427dcb4b 364 }
2821104d
JH
365 /* We do not need the text anymore */
366 diff_free_filespec_data(two);
427dcb4b
JH
367 dst_cnt++;
368 }
369 /* cost matrix sorted by most to least similar pair */
370 qsort(mx, num_create * num_src, sizeof(*mx), score_compare);
371 for (i = 0; i < num_create * num_src; i++) {
25d5ea41
JH
372 struct diff_rename_dst *dst = &rename_dst[mx[i].dst];
373 if (dst->pair)
374 continue; /* already done, either exact or fuzzy. */
427dcb4b 375 if (mx[i].score < minimum_score)
15d061b4 376 break; /* there is no more usable pair. */
5098bafb
JH
377 record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
378 rename_count++;
427dcb4b
JH
379 }
380 free(mx);
427dcb4b 381
15d061b4 382 cleanup:
427dcb4b 383 /* At this point, we have found some renames and copies and they
5098bafb 384 * are recorded in rename_dst. The original list is still in *q.
427dcb4b 385 */
25d5ea41
JH
386 outq.queue = NULL;
387 outq.nr = outq.alloc = 0;
427dcb4b 388 for (i = 0; i < q->nr; i++) {
25d5ea41 389 struct diff_filepair *p = q->queue[i];
25d5ea41
JH
390 struct diff_filepair *pair_to_free = NULL;
391
2cd68882
JH
392 if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
393 /*
394 * Creation
395 *
396 * We would output this create record if it has
397 * not been turned into a rename/copy already.
398 */
399 struct diff_rename_dst *dst =
400 locate_rename_dst(p->two, 0);
401 if (dst && dst->pair) {
25d5ea41
JH
402 diff_q(&outq, dst->pair);
403 pair_to_free = p;
404 }
405 else
2cd68882
JH
406 /* no matching rename/copy source, so
407 * record this as a creation.
25d5ea41
JH
408 */
409 diff_q(&outq, p);
427dcb4b 410 }
2cd68882
JH
411 else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) {
412 /*
413 * Deletion
414 *
f345b0a0
JH
415 * We would output this delete record if:
416 *
417 * (1) this is a broken delete and the counterpart
418 * broken create remains in the output; or
5098bafb
JH
419 * (2) this is not a broken delete, and rename_dst
420 * does not have a rename/copy to move p->one->path
421 * out of existence.
f345b0a0
JH
422 *
423 * Otherwise, the counterpart broken create
424 * has been turned into a rename-edit; or
425 * delete did not have a matching create to
426 * begin with.
2cd68882 427 */
f345b0a0
JH
428 if (DIFF_PAIR_BROKEN(p)) {
429 /* broken delete */
430 struct diff_rename_dst *dst =
431 locate_rename_dst(p->one, 0);
432 if (dst && dst->pair)
433 /* counterpart is now rename/copy */
434 pair_to_free = p;
435 }
436 else {
5098bafb
JH
437 for (j = 0; j < rename_dst_nr; j++) {
438 if (!rename_dst[j].pair)
439 continue;
440 if (strcmp(rename_dst[j].pair->
441 one->path,
442 p->one->path))
443 continue;
444 break;
445 }
446 if (j < rename_dst_nr)
f345b0a0
JH
447 /* this path remains */
448 pair_to_free = p;
449 }
2cd68882
JH
450
451 if (pair_to_free)
452 ;
453 else
454 diff_q(&outq, p);
455 }
25d5ea41 456 else if (!diff_unmodified_pair(p))
15d061b4 457 /* all the usual ones need to be kept */
25d5ea41 458 diff_q(&outq, p);
15d061b4
JH
459 else
460 /* no need to keep unmodified pairs */
461 pair_to_free = p;
462
226406f6
JH
463 if (pair_to_free)
464 diff_free_filepair(pair_to_free);
427dcb4b 465 }
25d5ea41 466 diff_debug_queue("done copying original", &outq);
427dcb4b 467
25d5ea41
JH
468 free(q->queue);
469 *q = outq;
470 diff_debug_queue("done collapsing", q);
427dcb4b 471
6bac10d8
JH
472 /* We need to see which rename source really stays here;
473 * earlier we only checked if the path is left in the result,
474 * but even if a path remains in the result, if that is coming
475 * from copying something else on top of it, then the original
476 * source is lost and does not stay.
477 */
478 for (i = 0; i < q->nr; i++) {
479 struct diff_filepair *p = q->queue[i];
480 if (DIFF_PAIR_RENAME(p) && p->source_stays) {
481 /* If one appears as the target of a rename-copy,
482 * then mark p->source_stays = 0; otherwise
483 * leave it as is.
484 */
485 p->source_stays = compute_stays(q, p->one);
486 }
487 }
488
5098bafb
JH
489 for (i = 0; i < rename_dst_nr; i++) {
490 diff_free_filespec_data(rename_dst[i].two);
491 free(rename_dst[i].two);
492 }
493
25d5ea41
JH
494 free(rename_dst);
495 rename_dst = NULL;
496 rename_dst_nr = rename_dst_alloc = 0;
497 free(rename_src);
498 rename_src = NULL;
499 rename_src_nr = rename_src_alloc = 0;
427dcb4b
JH
500 return;
501}