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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)); | |
50 | rename_dst[first].two = two; | |
51 | rename_dst[first].pair = NULL; | |
52 | return &(rename_dst[first]); | |
427dcb4b JH |
53 | } |
54 | ||
15d061b4 | 55 | /* Table of rename/copy src files */ |
25d5ea41 JH |
56 | static struct diff_rename_src { |
57 | struct diff_filespec *one; | |
15d061b4 | 58 | unsigned src_stays : 1; |
25d5ea41 JH |
59 | } *rename_src; |
60 | static int rename_src_nr, rename_src_alloc; | |
427dcb4b | 61 | |
15d061b4 JH |
62 | static struct diff_rename_src *register_rename_src(struct diff_filespec *one, |
63 | int src_stays) | |
25d5ea41 JH |
64 | { |
65 | int first, last; | |
66 | ||
67 | first = 0; | |
68 | last = rename_src_nr; | |
69 | while (last > first) { | |
70 | int next = (last + first) >> 1; | |
71 | struct diff_rename_src *src = &(rename_src[next]); | |
72 | int cmp = strcmp(one->path, src->one->path); | |
73 | if (!cmp) | |
74 | return src; | |
75 | if (cmp < 0) { | |
76 | last = next; | |
77 | continue; | |
78 | } | |
79 | first = next+1; | |
80 | } | |
15d061b4 | 81 | |
25d5ea41 JH |
82 | /* insert to make it at "first" */ |
83 | if (rename_src_alloc <= rename_src_nr) { | |
84 | rename_src_alloc = alloc_nr(rename_src_alloc); | |
85 | rename_src = xrealloc(rename_src, | |
86 | rename_src_alloc * sizeof(*rename_src)); | |
427dcb4b | 87 | } |
25d5ea41 JH |
88 | rename_src_nr++; |
89 | if (first < rename_src_nr) | |
90 | memmove(rename_src + first + 1, rename_src + first, | |
91 | (rename_src_nr - first - 1) * sizeof(*rename_src)); | |
92 | rename_src[first].one = one; | |
15d061b4 | 93 | rename_src[first].src_stays = src_stays; |
25d5ea41 | 94 | return &(rename_src[first]); |
427dcb4b JH |
95 | } |
96 | ||
97 | static int is_exact_match(struct diff_filespec *src, struct diff_filespec *dst) | |
98 | { | |
99 | if (src->sha1_valid && dst->sha1_valid && | |
100 | !memcmp(src->sha1, dst->sha1, 20)) | |
101 | return 1; | |
f0c6b2a2 JH |
102 | if (diff_populate_filespec(src, 1) || diff_populate_filespec(dst, 1)) |
103 | return 0; | |
104 | if (src->size != dst->size) | |
105 | return 0; | |
106 | if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0)) | |
427dcb4b JH |
107 | return 0; |
108 | if (src->size == dst->size && | |
109 | !memcmp(src->data, dst->data, src->size)) | |
110 | return 1; | |
111 | return 0; | |
112 | } | |
113 | ||
114 | struct diff_score { | |
25d5ea41 JH |
115 | int src; /* index in rename_src */ |
116 | int dst; /* index in rename_dst */ | |
427dcb4b | 117 | int score; |
427dcb4b JH |
118 | }; |
119 | ||
120 | static int estimate_similarity(struct diff_filespec *src, | |
121 | struct diff_filespec *dst, | |
122 | int minimum_score) | |
123 | { | |
124 | /* src points at a file that existed in the original tree (or | |
125 | * optionally a file in the destination tree) and dst points | |
126 | * at a newly created file. They may be quite similar, in which | |
127 | * case we want to say src is renamed to dst or src is copied into | |
128 | * dst, and then some edit has been applied to dst. | |
129 | * | |
130 | * Compare them and return how similar they are, representing | |
f0c6b2a2 JH |
131 | * the score as an integer between 0 and MAX_SCORE. |
132 | * | |
133 | * When there is an exact match, it is considered a better | |
134 | * match than anything else; the destination does not even | |
135 | * call into this function in that case. | |
427dcb4b JH |
136 | */ |
137 | void *delta; | |
355e76a4 | 138 | unsigned long delta_size, base_size, src_copied, literal_added; |
75c660ac | 139 | unsigned long delta_limit; |
427dcb4b JH |
140 | int score; |
141 | ||
60896c7b JH |
142 | /* We deal only with regular files. Symlink renames are handled |
143 | * only when they are exact matches --- in other words, no edits | |
144 | * after renaming. | |
145 | */ | |
146 | if (!S_ISREG(src->mode) || !S_ISREG(dst->mode)) | |
147 | return 0; | |
148 | ||
427dcb4b JH |
149 | delta_size = ((src->size < dst->size) ? |
150 | (dst->size - src->size) : (src->size - dst->size)); | |
58b103f5 | 151 | base_size = ((src->size < dst->size) ? src->size : dst->size); |
427dcb4b | 152 | |
58b103f5 JH |
153 | /* We would not consider edits that change the file size so |
154 | * drastically. delta_size must be smaller than | |
cd1870ed | 155 | * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size). |
f0c6b2a2 | 156 | * |
58b103f5 JH |
157 | * Note that base_size == 0 case is handled here already |
158 | * and the final score computation below would not have a | |
159 | * divide-by-zero issue. | |
427dcb4b | 160 | */ |
cd1870ed | 161 | if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE) |
427dcb4b JH |
162 | return 0; |
163 | ||
f0c6b2a2 JH |
164 | if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0)) |
165 | return 0; /* error but caught downstream */ | |
166 | ||
75c660ac | 167 | delta_limit = base_size * (MAX_SCORE-minimum_score) / MAX_SCORE; |
427dcb4b JH |
168 | delta = diff_delta(src->data, src->size, |
169 | dst->data, dst->size, | |
75c660ac JH |
170 | &delta_size, delta_limit); |
171 | if (!delta) | |
172 | /* If delta_limit is exceeded, we have too much differences */ | |
173 | return 0; | |
85976974 JH |
174 | |
175 | /* A delta that has a lot of literal additions would have | |
176 | * big delta_size no matter what else it does. | |
58b103f5 | 177 | */ |
a00d7d10 | 178 | if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE) |
85976974 JH |
179 | return 0; |
180 | ||
181 | /* Estimate the edit size by interpreting delta. */ | |
355e76a4 JH |
182 | if (count_delta(delta, delta_size, &src_copied, &literal_added)) { |
183 | free(delta); | |
85976974 | 184 | return 0; |
355e76a4 JH |
185 | } |
186 | free(delta); | |
187 | ||
188 | /* Extent of damage */ | |
189 | if (src->size + literal_added < src_copied) | |
190 | delta_size = 0; | |
191 | else | |
192 | delta_size = (src->size - src_copied) + literal_added; | |
427dcb4b | 193 | |
58b103f5 JH |
194 | /* |
195 | * Now we will give some score to it. 100% edit gets 0 points | |
196 | * and 0% edit gets MAX_SCORE points. | |
427dcb4b | 197 | */ |
58b103f5 | 198 | score = MAX_SCORE - (MAX_SCORE * delta_size / base_size); |
427dcb4b JH |
199 | if (score < 0) return 0; |
200 | if (MAX_SCORE < score) return MAX_SCORE; | |
201 | return score; | |
202 | } | |
203 | ||
25d5ea41 JH |
204 | static void record_rename_pair(struct diff_queue_struct *renq, |
205 | 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 | |
25d5ea41 | 221 | dp = diff_queue(renq, one, two); |
01c4e70f | 222 | dp->score = score; |
15d061b4 | 223 | dp->source_stays = rename_src[src_index].src_stays; |
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 | ||
6b14d7fa | 237 | void diffcore_rename(int detect_rename, int minimum_score) |
427dcb4b | 238 | { |
38c6f780 | 239 | struct diff_queue_struct *q = &diff_queued_diff; |
25d5ea41 | 240 | struct diff_queue_struct renq, outq; |
427dcb4b | 241 | struct diff_score *mx; |
25d5ea41 JH |
242 | int i, j; |
243 | int num_create, num_src, dst_cnt; | |
427dcb4b | 244 | |
26dee0ad | 245 | if (!minimum_score) |
f345b0a0 | 246 | minimum_score = DEFAULT_RENAME_SCORE; |
25d5ea41 JH |
247 | renq.queue = NULL; |
248 | renq.nr = renq.alloc = 0; | |
427dcb4b | 249 | |
427dcb4b | 250 | for (i = 0; i < q->nr; i++) { |
52e95789 | 251 | struct diff_filepair *p = q->queue[i]; |
81e50eab JH |
252 | if (!DIFF_FILE_VALID(p->one)) |
253 | if (!DIFF_FILE_VALID(p->two)) | |
60896c7b | 254 | continue; /* unmerged */ |
427dcb4b | 255 | else |
25d5ea41 | 256 | locate_rename_dst(p->two, 1); |
2210100a JH |
257 | else if (!DIFF_FILE_VALID(p->two)) { |
258 | /* If the source is a broken "delete", and | |
259 | * they did not really want to get broken, | |
260 | * that means the source actually stays. | |
261 | */ | |
262 | int stays = (p->broken_pair && !p->score); | |
263 | register_rename_src(p->one, stays); | |
264 | } | |
15d061b4 JH |
265 | else if (detect_rename == DIFF_DETECT_COPY) |
266 | register_rename_src(p->one, 1); | |
427dcb4b | 267 | } |
25d5ea41 | 268 | if (rename_dst_nr == 0) |
427dcb4b JH |
269 | goto cleanup; /* nothing to do */ |
270 | ||
271 | /* We really want to cull the candidates list early | |
272 | * with cheap tests in order to avoid doing deltas. | |
427dcb4b | 273 | */ |
25d5ea41 JH |
274 | for (i = 0; i < rename_dst_nr; i++) { |
275 | struct diff_filespec *two = rename_dst[i].two; | |
276 | for (j = 0; j < rename_src_nr; j++) { | |
277 | struct diff_filespec *one = rename_src[j].one; | |
278 | if (!is_exact_match(one, two)) | |
279 | continue; | |
280 | record_rename_pair(&renq, i, j, MAX_SCORE); | |
281 | break; /* we are done with this entry */ | |
427dcb4b JH |
282 | } |
283 | } | |
25d5ea41 | 284 | diff_debug_queue("done detecting exact", &renq); |
427dcb4b JH |
285 | |
286 | /* Have we run out the created file pool? If so we can avoid | |
287 | * doing the delta matrix altogether. | |
288 | */ | |
25d5ea41 | 289 | if (renq.nr == rename_dst_nr) |
15d061b4 | 290 | goto cleanup; |
427dcb4b | 291 | |
25d5ea41 JH |
292 | num_create = (rename_dst_nr - renq.nr); |
293 | num_src = rename_src_nr; | |
427dcb4b | 294 | mx = xmalloc(sizeof(*mx) * num_create * num_src); |
25d5ea41 | 295 | for (dst_cnt = i = 0; i < rename_dst_nr; i++) { |
427dcb4b | 296 | int base = dst_cnt * num_src; |
25d5ea41 JH |
297 | struct diff_filespec *two = rename_dst[i].two; |
298 | if (rename_dst[i].pair) | |
427dcb4b | 299 | continue; /* dealt with exact match already. */ |
25d5ea41 JH |
300 | for (j = 0; j < rename_src_nr; j++) { |
301 | struct diff_filespec *one = rename_src[j].one; | |
302 | struct diff_score *m = &mx[base+j]; | |
303 | m->src = j; | |
304 | m->dst = i; | |
305 | m->score = estimate_similarity(one, two, | |
306 | minimum_score); | |
427dcb4b JH |
307 | } |
308 | dst_cnt++; | |
309 | } | |
310 | /* cost matrix sorted by most to least similar pair */ | |
311 | qsort(mx, num_create * num_src, sizeof(*mx), score_compare); | |
312 | for (i = 0; i < num_create * num_src; i++) { | |
25d5ea41 JH |
313 | struct diff_rename_dst *dst = &rename_dst[mx[i].dst]; |
314 | if (dst->pair) | |
315 | continue; /* already done, either exact or fuzzy. */ | |
427dcb4b | 316 | if (mx[i].score < minimum_score) |
15d061b4 | 317 | break; /* there is no more usable pair. */ |
25d5ea41 | 318 | record_rename_pair(&renq, mx[i].dst, mx[i].src, mx[i].score); |
427dcb4b JH |
319 | } |
320 | free(mx); | |
25d5ea41 | 321 | diff_debug_queue("done detecting fuzzy", &renq); |
427dcb4b | 322 | |
15d061b4 | 323 | cleanup: |
427dcb4b | 324 | /* At this point, we have found some renames and copies and they |
25d5ea41 | 325 | * are kept in renq. The original list is still in *q. |
427dcb4b | 326 | */ |
25d5ea41 JH |
327 | outq.queue = NULL; |
328 | outq.nr = outq.alloc = 0; | |
427dcb4b | 329 | for (i = 0; i < q->nr; i++) { |
25d5ea41 | 330 | struct diff_filepair *p = q->queue[i]; |
25d5ea41 JH |
331 | struct diff_filepair *pair_to_free = NULL; |
332 | ||
2cd68882 JH |
333 | if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) { |
334 | /* | |
335 | * Creation | |
336 | * | |
337 | * We would output this create record if it has | |
338 | * not been turned into a rename/copy already. | |
339 | */ | |
340 | struct diff_rename_dst *dst = | |
341 | locate_rename_dst(p->two, 0); | |
342 | if (dst && dst->pair) { | |
25d5ea41 JH |
343 | diff_q(&outq, dst->pair); |
344 | pair_to_free = p; | |
345 | } | |
346 | else | |
2cd68882 JH |
347 | /* no matching rename/copy source, so |
348 | * record this as a creation. | |
25d5ea41 JH |
349 | */ |
350 | diff_q(&outq, p); | |
427dcb4b | 351 | } |
2cd68882 JH |
352 | else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) { |
353 | /* | |
354 | * Deletion | |
355 | * | |
f345b0a0 JH |
356 | * We would output this delete record if: |
357 | * | |
358 | * (1) this is a broken delete and the counterpart | |
359 | * broken create remains in the output; or | |
360 | * (2) this is not a broken delete, and renq does | |
361 | * not have a rename/copy to move p->one->path | |
362 | * out. | |
363 | * | |
364 | * Otherwise, the counterpart broken create | |
365 | * has been turned into a rename-edit; or | |
366 | * delete did not have a matching create to | |
367 | * begin with. | |
2cd68882 | 368 | */ |
f345b0a0 JH |
369 | if (DIFF_PAIR_BROKEN(p)) { |
370 | /* broken delete */ | |
371 | struct diff_rename_dst *dst = | |
372 | locate_rename_dst(p->one, 0); | |
373 | if (dst && dst->pair) | |
374 | /* counterpart is now rename/copy */ | |
375 | pair_to_free = p; | |
376 | } | |
377 | else { | |
378 | for (j = 0; j < renq.nr; j++) | |
379 | if (!strcmp(renq.queue[j]->one->path, | |
380 | p->one->path)) | |
381 | break; | |
382 | if (j < renq.nr) | |
383 | /* this path remains */ | |
384 | pair_to_free = p; | |
385 | } | |
2cd68882 JH |
386 | |
387 | if (pair_to_free) | |
388 | ; | |
389 | else | |
390 | diff_q(&outq, p); | |
391 | } | |
25d5ea41 | 392 | else if (!diff_unmodified_pair(p)) |
15d061b4 | 393 | /* all the usual ones need to be kept */ |
25d5ea41 | 394 | diff_q(&outq, p); |
15d061b4 JH |
395 | else |
396 | /* no need to keep unmodified pairs */ | |
397 | pair_to_free = p; | |
398 | ||
226406f6 JH |
399 | if (pair_to_free) |
400 | diff_free_filepair(pair_to_free); | |
427dcb4b | 401 | } |
25d5ea41 | 402 | diff_debug_queue("done copying original", &outq); |
427dcb4b | 403 | |
25d5ea41 JH |
404 | free(renq.queue); |
405 | free(q->queue); | |
406 | *q = outq; | |
407 | diff_debug_queue("done collapsing", q); | |
427dcb4b | 408 | |
25d5ea41 JH |
409 | free(rename_dst); |
410 | rename_dst = NULL; | |
411 | rename_dst_nr = rename_dst_alloc = 0; | |
412 | free(rename_src); | |
413 | rename_src = NULL; | |
414 | rename_src_nr = rename_src_alloc = 0; | |
427dcb4b JH |
415 | return; |
416 | } |