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Commit | Line | Data |
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427dcb4b JH |
1 | /* |
2 | * Copyright (C) 2005 Junio C Hamano | |
3 | */ | |
4 | #include "cache.h" | |
5 | #include "diff.h" | |
6 | #include "diffcore.h" | |
7 | #include "delta.h" | |
85976974 | 8 | #include "count-delta.h" |
427dcb4b | 9 | |
25d5ea41 JH |
10 | /* Table of rename/copy destinations */ |
11 | ||
12 | static struct diff_rename_dst { | |
13 | struct diff_filespec *two; | |
14 | struct diff_filepair *pair; | |
15 | } *rename_dst; | |
16 | static int rename_dst_nr, rename_dst_alloc; | |
427dcb4b | 17 | |
25d5ea41 JH |
18 | static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two, |
19 | int insert_ok) | |
427dcb4b | 20 | { |
25d5ea41 JH |
21 | int first, last; |
22 | ||
23 | first = 0; | |
24 | last = rename_dst_nr; | |
25 | while (last > first) { | |
26 | int next = (last + first) >> 1; | |
27 | struct diff_rename_dst *dst = &(rename_dst[next]); | |
28 | int cmp = strcmp(two->path, dst->two->path); | |
29 | if (!cmp) | |
30 | return dst; | |
31 | if (cmp < 0) { | |
32 | last = next; | |
33 | continue; | |
34 | } | |
35 | first = next+1; | |
36 | } | |
37 | /* not found */ | |
38 | if (!insert_ok) | |
39 | return NULL; | |
40 | /* insert to make it at "first" */ | |
41 | if (rename_dst_alloc <= rename_dst_nr) { | |
42 | rename_dst_alloc = alloc_nr(rename_dst_alloc); | |
43 | rename_dst = xrealloc(rename_dst, | |
44 | rename_dst_alloc * sizeof(*rename_dst)); | |
45 | } | |
46 | rename_dst_nr++; | |
47 | if (first < rename_dst_nr) | |
48 | memmove(rename_dst + first + 1, rename_dst + first, | |
49 | (rename_dst_nr - first - 1) * sizeof(*rename_dst)); | |
5098bafb JH |
50 | rename_dst[first].two = alloc_filespec(two->path); |
51 | fill_filespec(rename_dst[first].two, two->sha1, two->mode); | |
25d5ea41 JH |
52 | rename_dst[first].pair = NULL; |
53 | return &(rename_dst[first]); | |
427dcb4b JH |
54 | } |
55 | ||
15d061b4 | 56 | /* Table of rename/copy src files */ |
25d5ea41 JH |
57 | static struct diff_rename_src { |
58 | struct diff_filespec *one; | |
6bac10d8 | 59 | unsigned src_path_left : 1; |
25d5ea41 JH |
60 | } *rename_src; |
61 | static int rename_src_nr, rename_src_alloc; | |
427dcb4b | 62 | |
15d061b4 | 63 | static struct diff_rename_src *register_rename_src(struct diff_filespec *one, |
6bac10d8 | 64 | int src_path_left) |
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; | |
6bac10d8 | 94 | rename_src[first].src_path_left = src_path_left; |
25d5ea41 | 95 | return &(rename_src[first]); |
427dcb4b JH |
96 | } |
97 | ||
98 | static int is_exact_match(struct diff_filespec *src, struct diff_filespec *dst) | |
99 | { | |
100 | if (src->sha1_valid && dst->sha1_valid && | |
101 | !memcmp(src->sha1, dst->sha1, 20)) | |
102 | return 1; | |
f0c6b2a2 JH |
103 | if (diff_populate_filespec(src, 1) || diff_populate_filespec(dst, 1)) |
104 | return 0; | |
105 | if (src->size != dst->size) | |
106 | return 0; | |
107 | if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0)) | |
427dcb4b JH |
108 | return 0; |
109 | if (src->size == dst->size && | |
110 | !memcmp(src->data, dst->data, src->size)) | |
111 | return 1; | |
112 | return 0; | |
113 | } | |
114 | ||
115 | struct diff_score { | |
25d5ea41 JH |
116 | int src; /* index in rename_src */ |
117 | int dst; /* index in rename_dst */ | |
427dcb4b | 118 | int score; |
427dcb4b JH |
119 | }; |
120 | ||
121 | static int estimate_similarity(struct diff_filespec *src, | |
122 | struct diff_filespec *dst, | |
123 | int minimum_score) | |
124 | { | |
125 | /* src points at a file that existed in the original tree (or | |
126 | * optionally a file in the destination tree) and dst points | |
127 | * at a newly created file. They may be quite similar, in which | |
128 | * case we want to say src is renamed to dst or src is copied into | |
129 | * dst, and then some edit has been applied to dst. | |
130 | * | |
131 | * Compare them and return how similar they are, representing | |
f0c6b2a2 JH |
132 | * the score as an integer between 0 and MAX_SCORE. |
133 | * | |
134 | * When there is an exact match, it is considered a better | |
135 | * match than anything else; the destination does not even | |
136 | * call into this function in that case. | |
427dcb4b JH |
137 | */ |
138 | void *delta; | |
355e76a4 | 139 | unsigned long delta_size, base_size, src_copied, literal_added; |
75c660ac | 140 | unsigned long delta_limit; |
427dcb4b JH |
141 | int score; |
142 | ||
60896c7b JH |
143 | /* We deal only with regular files. Symlink renames are handled |
144 | * only when they are exact matches --- in other words, no edits | |
145 | * after renaming. | |
146 | */ | |
147 | if (!S_ISREG(src->mode) || !S_ISREG(dst->mode)) | |
148 | return 0; | |
149 | ||
427dcb4b JH |
150 | delta_size = ((src->size < dst->size) ? |
151 | (dst->size - src->size) : (src->size - dst->size)); | |
58b103f5 | 152 | base_size = ((src->size < dst->size) ? src->size : dst->size); |
427dcb4b | 153 | |
58b103f5 JH |
154 | /* We would not consider edits that change the file size so |
155 | * drastically. delta_size must be smaller than | |
cd1870ed | 156 | * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size). |
f0c6b2a2 | 157 | * |
58b103f5 JH |
158 | * Note that base_size == 0 case is handled here already |
159 | * and the final score computation below would not have a | |
160 | * divide-by-zero issue. | |
427dcb4b | 161 | */ |
cd1870ed | 162 | if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE) |
427dcb4b JH |
163 | return 0; |
164 | ||
f0c6b2a2 JH |
165 | if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0)) |
166 | return 0; /* error but caught downstream */ | |
167 | ||
75c660ac | 168 | delta_limit = base_size * (MAX_SCORE-minimum_score) / MAX_SCORE; |
427dcb4b JH |
169 | delta = diff_delta(src->data, src->size, |
170 | dst->data, dst->size, | |
75c660ac JH |
171 | &delta_size, delta_limit); |
172 | if (!delta) | |
173 | /* If delta_limit is exceeded, we have too much differences */ | |
174 | return 0; | |
85976974 JH |
175 | |
176 | /* A delta that has a lot of literal additions would have | |
177 | * big delta_size no matter what else it does. | |
58b103f5 | 178 | */ |
a00d7d10 | 179 | if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE) |
85976974 JH |
180 | return 0; |
181 | ||
182 | /* Estimate the edit size by interpreting delta. */ | |
355e76a4 JH |
183 | if (count_delta(delta, delta_size, &src_copied, &literal_added)) { |
184 | free(delta); | |
85976974 | 185 | return 0; |
355e76a4 JH |
186 | } |
187 | free(delta); | |
188 | ||
189 | /* Extent of damage */ | |
190 | if (src->size + literal_added < src_copied) | |
191 | delta_size = 0; | |
192 | else | |
193 | delta_size = (src->size - src_copied) + literal_added; | |
427dcb4b | 194 | |
58b103f5 JH |
195 | /* |
196 | * Now we will give some score to it. 100% edit gets 0 points | |
197 | * and 0% edit gets MAX_SCORE points. | |
427dcb4b | 198 | */ |
58b103f5 | 199 | score = MAX_SCORE - (MAX_SCORE * delta_size / base_size); |
427dcb4b JH |
200 | if (score < 0) return 0; |
201 | if (MAX_SCORE < score) return MAX_SCORE; | |
202 | return score; | |
203 | } | |
204 | ||
5098bafb | 205 | static void record_rename_pair(int dst_index, int src_index, int score) |
427dcb4b | 206 | { |
25d5ea41 JH |
207 | struct diff_filespec *one, *two, *src, *dst; |
208 | struct diff_filepair *dp; | |
f7c1512a | 209 | |
25d5ea41 JH |
210 | if (rename_dst[dst_index].pair) |
211 | die("internal error: dst already matched."); | |
427dcb4b | 212 | |
25d5ea41 JH |
213 | src = rename_src[src_index].one; |
214 | one = alloc_filespec(src->path); | |
215 | fill_filespec(one, src->sha1, src->mode); | |
427dcb4b | 216 | |
25d5ea41 JH |
217 | dst = rename_dst[dst_index].two; |
218 | two = alloc_filespec(dst->path); | |
219 | fill_filespec(two, dst->sha1, dst->mode); | |
427dcb4b | 220 | |
5098bafb | 221 | dp = diff_queue(NULL, one, two); |
01c4e70f | 222 | dp->score = score; |
6bac10d8 | 223 | dp->source_stays = rename_src[src_index].src_path_left; |
25d5ea41 | 224 | rename_dst[dst_index].pair = dp; |
427dcb4b JH |
225 | } |
226 | ||
227 | /* | |
228 | * We sort the rename similarity matrix with the score, in descending | |
15d061b4 | 229 | * order (the most similar first). |
427dcb4b JH |
230 | */ |
231 | static int score_compare(const void *a_, const void *b_) | |
232 | { | |
233 | const struct diff_score *a = a_, *b = b_; | |
234 | return b->score - a->score; | |
235 | } | |
236 | ||
6bac10d8 JH |
237 | static int compute_stays(struct diff_queue_struct *q, |
238 | struct diff_filespec *one) | |
239 | { | |
240 | int i; | |
241 | for (i = 0; i < q->nr; i++) { | |
242 | struct diff_filepair *p = q->queue[i]; | |
243 | if (strcmp(one->path, p->two->path)) | |
244 | continue; | |
245 | if (DIFF_PAIR_RENAME(p)) { | |
246 | return 0; /* something else is renamed into this */ | |
247 | } | |
248 | } | |
249 | return 1; | |
250 | } | |
251 | ||
8082d8d3 | 252 | void diffcore_rename(struct diff_options *options) |
427dcb4b | 253 | { |
8082d8d3 JH |
254 | int detect_rename = options->detect_rename; |
255 | int minimum_score = options->rename_score; | |
256 | int rename_limit = options->rename_limit; | |
38c6f780 | 257 | struct diff_queue_struct *q = &diff_queued_diff; |
5098bafb | 258 | struct diff_queue_struct outq; |
427dcb4b | 259 | struct diff_score *mx; |
5098bafb | 260 | int i, j, rename_count; |
25d5ea41 | 261 | int num_create, num_src, dst_cnt; |
427dcb4b | 262 | |
26dee0ad | 263 | if (!minimum_score) |
f345b0a0 | 264 | minimum_score = DEFAULT_RENAME_SCORE; |
5098bafb | 265 | rename_count = 0; |
427dcb4b | 266 | |
427dcb4b | 267 | for (i = 0; i < q->nr; i++) { |
52e95789 | 268 | struct diff_filepair *p = q->queue[i]; |
81e50eab JH |
269 | if (!DIFF_FILE_VALID(p->one)) |
270 | if (!DIFF_FILE_VALID(p->two)) | |
60896c7b | 271 | continue; /* unmerged */ |
427dcb4b | 272 | else |
25d5ea41 | 273 | locate_rename_dst(p->two, 1); |
2210100a JH |
274 | else if (!DIFF_FILE_VALID(p->two)) { |
275 | /* If the source is a broken "delete", and | |
276 | * they did not really want to get broken, | |
277 | * that means the source actually stays. | |
278 | */ | |
279 | int stays = (p->broken_pair && !p->score); | |
280 | register_rename_src(p->one, stays); | |
281 | } | |
15d061b4 JH |
282 | else if (detect_rename == DIFF_DETECT_COPY) |
283 | register_rename_src(p->one, 1); | |
427dcb4b | 284 | } |
7d6fb370 | 285 | if (rename_dst_nr == 0 || rename_src_nr == 0 || |
3299c6f6 | 286 | (0 < rename_limit && rename_limit < rename_dst_nr)) |
427dcb4b JH |
287 | goto cleanup; /* nothing to do */ |
288 | ||
289 | /* We really want to cull the candidates list early | |
290 | * with cheap tests in order to avoid doing deltas. | |
427dcb4b | 291 | */ |
25d5ea41 JH |
292 | for (i = 0; i < rename_dst_nr; i++) { |
293 | struct diff_filespec *two = rename_dst[i].two; | |
294 | for (j = 0; j < rename_src_nr; j++) { | |
295 | struct diff_filespec *one = rename_src[j].one; | |
296 | if (!is_exact_match(one, two)) | |
297 | continue; | |
5098bafb JH |
298 | record_rename_pair(i, j, MAX_SCORE); |
299 | rename_count++; | |
25d5ea41 | 300 | break; /* we are done with this entry */ |
427dcb4b JH |
301 | } |
302 | } | |
427dcb4b JH |
303 | |
304 | /* Have we run out the created file pool? If so we can avoid | |
305 | * doing the delta matrix altogether. | |
306 | */ | |
5098bafb | 307 | if (rename_count == rename_dst_nr) |
15d061b4 | 308 | goto cleanup; |
427dcb4b | 309 | |
9f70b806 JH |
310 | if (minimum_score == MAX_SCORE) |
311 | goto cleanup; | |
312 | ||
5098bafb | 313 | num_create = (rename_dst_nr - rename_count); |
25d5ea41 | 314 | num_src = rename_src_nr; |
427dcb4b | 315 | mx = xmalloc(sizeof(*mx) * num_create * num_src); |
25d5ea41 | 316 | for (dst_cnt = i = 0; i < rename_dst_nr; i++) { |
427dcb4b | 317 | int base = dst_cnt * num_src; |
25d5ea41 JH |
318 | struct diff_filespec *two = rename_dst[i].two; |
319 | if (rename_dst[i].pair) | |
427dcb4b | 320 | continue; /* dealt with exact match already. */ |
25d5ea41 JH |
321 | for (j = 0; j < rename_src_nr; j++) { |
322 | struct diff_filespec *one = rename_src[j].one; | |
323 | struct diff_score *m = &mx[base+j]; | |
324 | m->src = j; | |
325 | m->dst = i; | |
326 | m->score = estimate_similarity(one, two, | |
327 | minimum_score); | |
427dcb4b JH |
328 | } |
329 | dst_cnt++; | |
330 | } | |
331 | /* cost matrix sorted by most to least similar pair */ | |
332 | qsort(mx, num_create * num_src, sizeof(*mx), score_compare); | |
333 | for (i = 0; i < num_create * num_src; i++) { | |
25d5ea41 JH |
334 | struct diff_rename_dst *dst = &rename_dst[mx[i].dst]; |
335 | if (dst->pair) | |
336 | continue; /* already done, either exact or fuzzy. */ | |
427dcb4b | 337 | if (mx[i].score < minimum_score) |
15d061b4 | 338 | break; /* there is no more usable pair. */ |
5098bafb JH |
339 | record_rename_pair(mx[i].dst, mx[i].src, mx[i].score); |
340 | rename_count++; | |
427dcb4b JH |
341 | } |
342 | free(mx); | |
427dcb4b | 343 | |
15d061b4 | 344 | cleanup: |
427dcb4b | 345 | /* At this point, we have found some renames and copies and they |
5098bafb | 346 | * are recorded in rename_dst. The original list is still in *q. |
427dcb4b | 347 | */ |
25d5ea41 JH |
348 | outq.queue = NULL; |
349 | outq.nr = outq.alloc = 0; | |
427dcb4b | 350 | for (i = 0; i < q->nr; i++) { |
25d5ea41 | 351 | struct diff_filepair *p = q->queue[i]; |
25d5ea41 JH |
352 | struct diff_filepair *pair_to_free = NULL; |
353 | ||
2cd68882 JH |
354 | if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) { |
355 | /* | |
356 | * Creation | |
357 | * | |
358 | * We would output this create record if it has | |
359 | * not been turned into a rename/copy already. | |
360 | */ | |
361 | struct diff_rename_dst *dst = | |
362 | locate_rename_dst(p->two, 0); | |
363 | if (dst && dst->pair) { | |
25d5ea41 JH |
364 | diff_q(&outq, dst->pair); |
365 | pair_to_free = p; | |
366 | } | |
367 | else | |
2cd68882 JH |
368 | /* no matching rename/copy source, so |
369 | * record this as a creation. | |
25d5ea41 JH |
370 | */ |
371 | diff_q(&outq, p); | |
427dcb4b | 372 | } |
2cd68882 JH |
373 | else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) { |
374 | /* | |
375 | * Deletion | |
376 | * | |
f345b0a0 JH |
377 | * We would output this delete record if: |
378 | * | |
379 | * (1) this is a broken delete and the counterpart | |
380 | * broken create remains in the output; or | |
5098bafb JH |
381 | * (2) this is not a broken delete, and rename_dst |
382 | * does not have a rename/copy to move p->one->path | |
383 | * out of existence. | |
f345b0a0 JH |
384 | * |
385 | * Otherwise, the counterpart broken create | |
386 | * has been turned into a rename-edit; or | |
387 | * delete did not have a matching create to | |
388 | * begin with. | |
2cd68882 | 389 | */ |
f345b0a0 JH |
390 | if (DIFF_PAIR_BROKEN(p)) { |
391 | /* broken delete */ | |
392 | struct diff_rename_dst *dst = | |
393 | locate_rename_dst(p->one, 0); | |
394 | if (dst && dst->pair) | |
395 | /* counterpart is now rename/copy */ | |
396 | pair_to_free = p; | |
397 | } | |
398 | else { | |
5098bafb JH |
399 | for (j = 0; j < rename_dst_nr; j++) { |
400 | if (!rename_dst[j].pair) | |
401 | continue; | |
402 | if (strcmp(rename_dst[j].pair-> | |
403 | one->path, | |
404 | p->one->path)) | |
405 | continue; | |
406 | break; | |
407 | } | |
408 | if (j < rename_dst_nr) | |
f345b0a0 JH |
409 | /* this path remains */ |
410 | pair_to_free = p; | |
411 | } | |
2cd68882 JH |
412 | |
413 | if (pair_to_free) | |
414 | ; | |
415 | else | |
416 | diff_q(&outq, p); | |
417 | } | |
25d5ea41 | 418 | else if (!diff_unmodified_pair(p)) |
15d061b4 | 419 | /* all the usual ones need to be kept */ |
25d5ea41 | 420 | diff_q(&outq, p); |
15d061b4 JH |
421 | else |
422 | /* no need to keep unmodified pairs */ | |
423 | pair_to_free = p; | |
424 | ||
226406f6 JH |
425 | if (pair_to_free) |
426 | diff_free_filepair(pair_to_free); | |
427dcb4b | 427 | } |
25d5ea41 | 428 | diff_debug_queue("done copying original", &outq); |
427dcb4b | 429 | |
25d5ea41 JH |
430 | free(q->queue); |
431 | *q = outq; | |
432 | diff_debug_queue("done collapsing", q); | |
427dcb4b | 433 | |
6bac10d8 JH |
434 | /* We need to see which rename source really stays here; |
435 | * earlier we only checked if the path is left in the result, | |
436 | * but even if a path remains in the result, if that is coming | |
437 | * from copying something else on top of it, then the original | |
438 | * source is lost and does not stay. | |
439 | */ | |
440 | for (i = 0; i < q->nr; i++) { | |
441 | struct diff_filepair *p = q->queue[i]; | |
442 | if (DIFF_PAIR_RENAME(p) && p->source_stays) { | |
443 | /* If one appears as the target of a rename-copy, | |
444 | * then mark p->source_stays = 0; otherwise | |
445 | * leave it as is. | |
446 | */ | |
447 | p->source_stays = compute_stays(q, p->one); | |
448 | } | |
449 | } | |
450 | ||
5098bafb JH |
451 | for (i = 0; i < rename_dst_nr; i++) { |
452 | diff_free_filespec_data(rename_dst[i].two); | |
453 | free(rename_dst[i].two); | |
454 | } | |
455 | ||
25d5ea41 JH |
456 | free(rename_dst); |
457 | rename_dst = NULL; | |
458 | rename_dst_nr = rename_dst_alloc = 0; | |
459 | free(rename_src); | |
460 | rename_src = NULL; | |
461 | rename_src_nr = rename_src_alloc = 0; | |
427dcb4b JH |
462 | return; |
463 | } |