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1 | #include "cache.h" | |
2 | #include "refs.h" | |
3 | #include "object-store.h" | |
4 | #include "cache-tree.h" | |
5 | #include "mergesort.h" | |
6 | #include "diff.h" | |
7 | #include "diffcore.h" | |
8 | #include "tag.h" | |
9 | #include "blame.h" | |
10 | #include "alloc.h" | |
11 | #include "commit-slab.h" | |
12 | ||
13 | define_commit_slab(blame_suspects, struct blame_origin *); | |
14 | static struct blame_suspects blame_suspects; | |
15 | ||
16 | struct blame_origin *get_blame_suspects(struct commit *commit) | |
17 | { | |
18 | struct blame_origin **result; | |
19 | ||
20 | result = blame_suspects_peek(&blame_suspects, commit); | |
21 | ||
22 | return result ? *result : NULL; | |
23 | } | |
24 | ||
25 | static void set_blame_suspects(struct commit *commit, struct blame_origin *origin) | |
26 | { | |
27 | *blame_suspects_at(&blame_suspects, commit) = origin; | |
28 | } | |
29 | ||
30 | void blame_origin_decref(struct blame_origin *o) | |
31 | { | |
32 | if (o && --o->refcnt <= 0) { | |
33 | struct blame_origin *p, *l = NULL; | |
34 | if (o->previous) | |
35 | blame_origin_decref(o->previous); | |
36 | free(o->file.ptr); | |
37 | /* Should be present exactly once in commit chain */ | |
38 | for (p = get_blame_suspects(o->commit); p; l = p, p = p->next) { | |
39 | if (p == o) { | |
40 | if (l) | |
41 | l->next = p->next; | |
42 | else | |
43 | set_blame_suspects(o->commit, p->next); | |
44 | free(o); | |
45 | return; | |
46 | } | |
47 | } | |
48 | die("internal error in blame_origin_decref"); | |
49 | } | |
50 | } | |
51 | ||
52 | /* | |
53 | * Given a commit and a path in it, create a new origin structure. | |
54 | * The callers that add blame to the scoreboard should use | |
55 | * get_origin() to obtain shared, refcounted copy instead of calling | |
56 | * this function directly. | |
57 | */ | |
58 | static struct blame_origin *make_origin(struct commit *commit, const char *path) | |
59 | { | |
60 | struct blame_origin *o; | |
61 | FLEX_ALLOC_STR(o, path, path); | |
62 | o->commit = commit; | |
63 | o->refcnt = 1; | |
64 | o->next = get_blame_suspects(commit); | |
65 | set_blame_suspects(commit, o); | |
66 | return o; | |
67 | } | |
68 | ||
69 | /* | |
70 | * Locate an existing origin or create a new one. | |
71 | * This moves the origin to front position in the commit util list. | |
72 | */ | |
73 | static struct blame_origin *get_origin(struct commit *commit, const char *path) | |
74 | { | |
75 | struct blame_origin *o, *l; | |
76 | ||
77 | for (o = get_blame_suspects(commit), l = NULL; o; l = o, o = o->next) { | |
78 | if (!strcmp(o->path, path)) { | |
79 | /* bump to front */ | |
80 | if (l) { | |
81 | l->next = o->next; | |
82 | o->next = get_blame_suspects(commit); | |
83 | set_blame_suspects(commit, o); | |
84 | } | |
85 | return blame_origin_incref(o); | |
86 | } | |
87 | } | |
88 | return make_origin(commit, path); | |
89 | } | |
90 | ||
91 | ||
92 | ||
93 | static void verify_working_tree_path(struct repository *r, | |
94 | struct commit *work_tree, const char *path) | |
95 | { | |
96 | struct commit_list *parents; | |
97 | int pos; | |
98 | ||
99 | for (parents = work_tree->parents; parents; parents = parents->next) { | |
100 | const struct object_id *commit_oid = &parents->item->object.oid; | |
101 | struct object_id blob_oid; | |
102 | unsigned short mode; | |
103 | ||
104 | if (!get_tree_entry(r, commit_oid, path, &blob_oid, &mode) && | |
105 | oid_object_info(r, &blob_oid, NULL) == OBJ_BLOB) | |
106 | return; | |
107 | } | |
108 | ||
109 | pos = index_name_pos(r->index, path, strlen(path)); | |
110 | if (pos >= 0) | |
111 | ; /* path is in the index */ | |
112 | else if (-1 - pos < r->index->cache_nr && | |
113 | !strcmp(r->index->cache[-1 - pos]->name, path)) | |
114 | ; /* path is in the index, unmerged */ | |
115 | else | |
116 | die("no such path '%s' in HEAD", path); | |
117 | } | |
118 | ||
119 | static struct commit_list **append_parent(struct repository *r, | |
120 | struct commit_list **tail, | |
121 | const struct object_id *oid) | |
122 | { | |
123 | struct commit *parent; | |
124 | ||
125 | parent = lookup_commit_reference(r, oid); | |
126 | if (!parent) | |
127 | die("no such commit %s", oid_to_hex(oid)); | |
128 | return &commit_list_insert(parent, tail)->next; | |
129 | } | |
130 | ||
131 | static void append_merge_parents(struct repository *r, | |
132 | struct commit_list **tail) | |
133 | { | |
134 | int merge_head; | |
135 | struct strbuf line = STRBUF_INIT; | |
136 | ||
137 | merge_head = open(git_path_merge_head(r), O_RDONLY); | |
138 | if (merge_head < 0) { | |
139 | if (errno == ENOENT) | |
140 | return; | |
141 | die("cannot open '%s' for reading", | |
142 | git_path_merge_head(r)); | |
143 | } | |
144 | ||
145 | while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) { | |
146 | struct object_id oid; | |
147 | if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid)) | |
148 | die("unknown line in '%s': %s", | |
149 | git_path_merge_head(r), line.buf); | |
150 | tail = append_parent(r, tail, &oid); | |
151 | } | |
152 | close(merge_head); | |
153 | strbuf_release(&line); | |
154 | } | |
155 | ||
156 | /* | |
157 | * This isn't as simple as passing sb->buf and sb->len, because we | |
158 | * want to transfer ownership of the buffer to the commit (so we | |
159 | * must use detach). | |
160 | */ | |
161 | static void set_commit_buffer_from_strbuf(struct repository *r, | |
162 | struct commit *c, | |
163 | struct strbuf *sb) | |
164 | { | |
165 | size_t len; | |
166 | void *buf = strbuf_detach(sb, &len); | |
167 | set_commit_buffer(r, c, buf, len); | |
168 | } | |
169 | ||
170 | /* | |
171 | * Prepare a dummy commit that represents the work tree (or staged) item. | |
172 | * Note that annotating work tree item never works in the reverse. | |
173 | */ | |
174 | static struct commit *fake_working_tree_commit(struct repository *r, | |
175 | struct diff_options *opt, | |
176 | const char *path, | |
177 | const char *contents_from) | |
178 | { | |
179 | struct commit *commit; | |
180 | struct blame_origin *origin; | |
181 | struct commit_list **parent_tail, *parent; | |
182 | struct object_id head_oid; | |
183 | struct strbuf buf = STRBUF_INIT; | |
184 | const char *ident; | |
185 | time_t now; | |
186 | int len; | |
187 | struct cache_entry *ce; | |
188 | unsigned mode; | |
189 | struct strbuf msg = STRBUF_INIT; | |
190 | ||
191 | repo_read_index(r); | |
192 | time(&now); | |
193 | commit = alloc_commit_node(r); | |
194 | commit->object.parsed = 1; | |
195 | commit->date = now; | |
196 | parent_tail = &commit->parents; | |
197 | ||
198 | if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL)) | |
199 | die("no such ref: HEAD"); | |
200 | ||
201 | parent_tail = append_parent(r, parent_tail, &head_oid); | |
202 | append_merge_parents(r, parent_tail); | |
203 | verify_working_tree_path(r, commit, path); | |
204 | ||
205 | origin = make_origin(commit, path); | |
206 | ||
207 | ident = fmt_ident("Not Committed Yet", "not.committed.yet", | |
208 | WANT_BLANK_IDENT, NULL, 0); | |
209 | strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n"); | |
210 | for (parent = commit->parents; parent; parent = parent->next) | |
211 | strbuf_addf(&msg, "parent %s\n", | |
212 | oid_to_hex(&parent->item->object.oid)); | |
213 | strbuf_addf(&msg, | |
214 | "author %s\n" | |
215 | "committer %s\n\n" | |
216 | "Version of %s from %s\n", | |
217 | ident, ident, path, | |
218 | (!contents_from ? path : | |
219 | (!strcmp(contents_from, "-") ? "standard input" : contents_from))); | |
220 | set_commit_buffer_from_strbuf(r, commit, &msg); | |
221 | ||
222 | if (!contents_from || strcmp("-", contents_from)) { | |
223 | struct stat st; | |
224 | const char *read_from; | |
225 | char *buf_ptr; | |
226 | unsigned long buf_len; | |
227 | ||
228 | if (contents_from) { | |
229 | if (stat(contents_from, &st) < 0) | |
230 | die_errno("Cannot stat '%s'", contents_from); | |
231 | read_from = contents_from; | |
232 | } | |
233 | else { | |
234 | if (lstat(path, &st) < 0) | |
235 | die_errno("Cannot lstat '%s'", path); | |
236 | read_from = path; | |
237 | } | |
238 | mode = canon_mode(st.st_mode); | |
239 | ||
240 | switch (st.st_mode & S_IFMT) { | |
241 | case S_IFREG: | |
242 | if (opt->flags.allow_textconv && | |
243 | textconv_object(r, read_from, mode, &null_oid, 0, &buf_ptr, &buf_len)) | |
244 | strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1); | |
245 | else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size) | |
246 | die_errno("cannot open or read '%s'", read_from); | |
247 | break; | |
248 | case S_IFLNK: | |
249 | if (strbuf_readlink(&buf, read_from, st.st_size) < 0) | |
250 | die_errno("cannot readlink '%s'", read_from); | |
251 | break; | |
252 | default: | |
253 | die("unsupported file type %s", read_from); | |
254 | } | |
255 | } | |
256 | else { | |
257 | /* Reading from stdin */ | |
258 | mode = 0; | |
259 | if (strbuf_read(&buf, 0, 0) < 0) | |
260 | die_errno("failed to read from stdin"); | |
261 | } | |
262 | convert_to_git(r->index, path, buf.buf, buf.len, &buf, 0); | |
263 | origin->file.ptr = buf.buf; | |
264 | origin->file.size = buf.len; | |
265 | pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid); | |
266 | ||
267 | /* | |
268 | * Read the current index, replace the path entry with | |
269 | * origin->blob_sha1 without mucking with its mode or type | |
270 | * bits; we are not going to write this index out -- we just | |
271 | * want to run "diff-index --cached". | |
272 | */ | |
273 | discard_index(r->index); | |
274 | repo_read_index(r); | |
275 | ||
276 | len = strlen(path); | |
277 | if (!mode) { | |
278 | int pos = index_name_pos(r->index, path, len); | |
279 | if (0 <= pos) | |
280 | mode = r->index->cache[pos]->ce_mode; | |
281 | else | |
282 | /* Let's not bother reading from HEAD tree */ | |
283 | mode = S_IFREG | 0644; | |
284 | } | |
285 | ce = make_empty_cache_entry(r->index, len); | |
286 | oidcpy(&ce->oid, &origin->blob_oid); | |
287 | memcpy(ce->name, path, len); | |
288 | ce->ce_flags = create_ce_flags(0); | |
289 | ce->ce_namelen = len; | |
290 | ce->ce_mode = create_ce_mode(mode); | |
291 | add_index_entry(r->index, ce, | |
292 | ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE); | |
293 | ||
294 | cache_tree_invalidate_path(r->index, path); | |
295 | ||
296 | return commit; | |
297 | } | |
298 | ||
299 | ||
300 | ||
301 | static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b, | |
302 | xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, int xdl_opts) | |
303 | { | |
304 | xpparam_t xpp = {0}; | |
305 | xdemitconf_t xecfg = {0}; | |
306 | xdemitcb_t ecb = {NULL}; | |
307 | ||
308 | xpp.flags = xdl_opts; | |
309 | xecfg.hunk_func = hunk_func; | |
310 | ecb.priv = cb_data; | |
311 | return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb); | |
312 | } | |
313 | ||
314 | static const char *get_next_line(const char *start, const char *end) | |
315 | { | |
316 | const char *nl = memchr(start, '\n', end - start); | |
317 | ||
318 | return nl ? nl + 1 : end; | |
319 | } | |
320 | ||
321 | static int find_line_starts(int **line_starts, const char *buf, | |
322 | unsigned long len) | |
323 | { | |
324 | const char *end = buf + len; | |
325 | const char *p; | |
326 | int *lineno; | |
327 | int num = 0; | |
328 | ||
329 | for (p = buf; p < end; p = get_next_line(p, end)) | |
330 | num++; | |
331 | ||
332 | ALLOC_ARRAY(*line_starts, num + 1); | |
333 | lineno = *line_starts; | |
334 | ||
335 | for (p = buf; p < end; p = get_next_line(p, end)) | |
336 | *lineno++ = p - buf; | |
337 | ||
338 | *lineno = len; | |
339 | ||
340 | return num; | |
341 | } | |
342 | ||
343 | struct fingerprint_entry; | |
344 | ||
345 | /* A fingerprint is intended to loosely represent a string, such that two | |
346 | * fingerprints can be quickly compared to give an indication of the similarity | |
347 | * of the strings that they represent. | |
348 | * | |
349 | * A fingerprint is represented as a multiset of the lower-cased byte pairs in | |
350 | * the string that it represents. Whitespace is added at each end of the | |
351 | * string. Whitespace pairs are ignored. Whitespace is converted to '\0'. | |
352 | * For example, the string "Darth Radar" will be converted to the following | |
353 | * fingerprint: | |
354 | * {"\0d", "da", "da", "ar", "ar", "rt", "th", "h\0", "\0r", "ra", "ad", "r\0"} | |
355 | * | |
356 | * The similarity between two fingerprints is the size of the intersection of | |
357 | * their multisets, including repeated elements. See fingerprint_similarity for | |
358 | * examples. | |
359 | * | |
360 | * For ease of implementation, the fingerprint is implemented as a map | |
361 | * of byte pairs to the count of that byte pair in the string, instead of | |
362 | * allowing repeated elements in a set. | |
363 | */ | |
364 | struct fingerprint { | |
365 | struct hashmap map; | |
366 | /* As we know the maximum number of entries in advance, it's | |
367 | * convenient to store the entries in a single array instead of having | |
368 | * the hashmap manage the memory. | |
369 | */ | |
370 | struct fingerprint_entry *entries; | |
371 | }; | |
372 | ||
373 | /* A byte pair in a fingerprint. Stores the number of times the byte pair | |
374 | * occurs in the string that the fingerprint represents. | |
375 | */ | |
376 | struct fingerprint_entry { | |
377 | /* The hashmap entry - the hash represents the byte pair in its | |
378 | * entirety so we don't need to store the byte pair separately. | |
379 | */ | |
380 | struct hashmap_entry entry; | |
381 | /* The number of times the byte pair occurs in the string that the | |
382 | * fingerprint represents. | |
383 | */ | |
384 | int count; | |
385 | }; | |
386 | ||
387 | /* See `struct fingerprint` for an explanation of what a fingerprint is. | |
388 | * \param result the fingerprint of the string is stored here. This must be | |
389 | * freed later using free_fingerprint. | |
390 | * \param line_begin the start of the string | |
391 | * \param line_end the end of the string | |
392 | */ | |
393 | static void get_fingerprint(struct fingerprint *result, | |
394 | const char *line_begin, | |
395 | const char *line_end) | |
396 | { | |
397 | unsigned int hash, c0 = 0, c1; | |
398 | const char *p; | |
399 | int max_map_entry_count = 1 + line_end - line_begin; | |
400 | struct fingerprint_entry *entry = xcalloc(max_map_entry_count, | |
401 | sizeof(struct fingerprint_entry)); | |
402 | struct fingerprint_entry *found_entry; | |
403 | ||
404 | hashmap_init(&result->map, NULL, NULL, max_map_entry_count); | |
405 | result->entries = entry; | |
406 | for (p = line_begin; p <= line_end; ++p, c0 = c1) { | |
407 | /* Always terminate the string with whitespace. | |
408 | * Normalise whitespace to 0, and normalise letters to | |
409 | * lower case. This won't work for multibyte characters but at | |
410 | * worst will match some unrelated characters. | |
411 | */ | |
412 | if ((p == line_end) || isspace(*p)) | |
413 | c1 = 0; | |
414 | else | |
415 | c1 = tolower(*p); | |
416 | hash = c0 | (c1 << 8); | |
417 | /* Ignore whitespace pairs */ | |
418 | if (hash == 0) | |
419 | continue; | |
420 | hashmap_entry_init(&entry->entry, hash); | |
421 | ||
422 | found_entry = hashmap_get(&result->map, entry, NULL); | |
423 | if (found_entry) { | |
424 | found_entry->count += 1; | |
425 | } else { | |
426 | entry->count = 1; | |
427 | hashmap_add(&result->map, &entry->entry); | |
428 | ++entry; | |
429 | } | |
430 | } | |
431 | } | |
432 | ||
433 | static void free_fingerprint(struct fingerprint *f) | |
434 | { | |
435 | hashmap_free(&f->map, 0); | |
436 | free(f->entries); | |
437 | } | |
438 | ||
439 | /* Calculates the similarity between two fingerprints as the size of the | |
440 | * intersection of their multisets, including repeated elements. See | |
441 | * `struct fingerprint` for an explanation of the fingerprint representation. | |
442 | * The similarity between "cat mat" and "father rather" is 2 because "at" is | |
443 | * present twice in both strings while the similarity between "tim" and "mit" | |
444 | * is 0. | |
445 | */ | |
446 | static int fingerprint_similarity(struct fingerprint *a, struct fingerprint *b) | |
447 | { | |
448 | int intersection = 0; | |
449 | struct hashmap_iter iter; | |
450 | const struct fingerprint_entry *entry_a, *entry_b; | |
451 | ||
452 | hashmap_iter_init(&b->map, &iter); | |
453 | ||
454 | while ((entry_b = hashmap_iter_next(&iter))) { | |
455 | if ((entry_a = hashmap_get(&a->map, entry_b, NULL))) { | |
456 | intersection += entry_a->count < entry_b->count ? | |
457 | entry_a->count : entry_b->count; | |
458 | } | |
459 | } | |
460 | return intersection; | |
461 | } | |
462 | ||
463 | /* Subtracts byte-pair elements in B from A, modifying A in place. | |
464 | */ | |
465 | static void fingerprint_subtract(struct fingerprint *a, struct fingerprint *b) | |
466 | { | |
467 | struct hashmap_iter iter; | |
468 | struct fingerprint_entry *entry_a; | |
469 | const struct fingerprint_entry *entry_b; | |
470 | ||
471 | hashmap_iter_init(&b->map, &iter); | |
472 | ||
473 | while ((entry_b = hashmap_iter_next(&iter))) { | |
474 | if ((entry_a = hashmap_get(&a->map, entry_b, NULL))) { | |
475 | if (entry_a->count <= entry_b->count) | |
476 | hashmap_remove(&a->map, entry_b, NULL); | |
477 | else | |
478 | entry_a->count -= entry_b->count; | |
479 | } | |
480 | } | |
481 | } | |
482 | ||
483 | /* Calculate fingerprints for a series of lines. | |
484 | * Puts the fingerprints in the fingerprints array, which must have been | |
485 | * preallocated to allow storing line_count elements. | |
486 | */ | |
487 | static void get_line_fingerprints(struct fingerprint *fingerprints, | |
488 | const char *content, const int *line_starts, | |
489 | long first_line, long line_count) | |
490 | { | |
491 | int i; | |
492 | const char *linestart, *lineend; | |
493 | ||
494 | line_starts += first_line; | |
495 | for (i = 0; i < line_count; ++i) { | |
496 | linestart = content + line_starts[i]; | |
497 | lineend = content + line_starts[i + 1]; | |
498 | get_fingerprint(fingerprints + i, linestart, lineend); | |
499 | } | |
500 | } | |
501 | ||
502 | static void free_line_fingerprints(struct fingerprint *fingerprints, | |
503 | int nr_fingerprints) | |
504 | { | |
505 | int i; | |
506 | ||
507 | for (i = 0; i < nr_fingerprints; i++) | |
508 | free_fingerprint(&fingerprints[i]); | |
509 | } | |
510 | ||
511 | /* This contains the data necessary to linearly map a line number in one half | |
512 | * of a diff chunk to the line in the other half of the diff chunk that is | |
513 | * closest in terms of its position as a fraction of the length of the chunk. | |
514 | */ | |
515 | struct line_number_mapping { | |
516 | int destination_start, destination_length, | |
517 | source_start, source_length; | |
518 | }; | |
519 | ||
520 | /* Given a line number in one range, offset and scale it to map it onto the | |
521 | * other range. | |
522 | * Essentially this mapping is a simple linear equation but the calculation is | |
523 | * more complicated to allow performing it with integer operations. | |
524 | * Another complication is that if a line could map onto many lines in the | |
525 | * destination range then we want to choose the line at the center of those | |
526 | * possibilities. | |
527 | * Example: if the chunk is 2 lines long in A and 10 lines long in B then the | |
528 | * first 5 lines in B will map onto the first line in the A chunk, while the | |
529 | * last 5 lines will all map onto the second line in the A chunk. | |
530 | * Example: if the chunk is 10 lines long in A and 2 lines long in B then line | |
531 | * 0 in B will map onto line 2 in A, and line 1 in B will map onto line 7 in A. | |
532 | */ | |
533 | static int map_line_number(int line_number, | |
534 | const struct line_number_mapping *mapping) | |
535 | { | |
536 | return ((line_number - mapping->source_start) * 2 + 1) * | |
537 | mapping->destination_length / | |
538 | (mapping->source_length * 2) + | |
539 | mapping->destination_start; | |
540 | } | |
541 | ||
542 | /* Get a pointer to the element storing the similarity between a line in A | |
543 | * and a line in B. | |
544 | * | |
545 | * The similarities are stored in a 2-dimensional array. Each "row" in the | |
546 | * array contains the similarities for a line in B. The similarities stored in | |
547 | * a row are the similarities between the line in B and the nearby lines in A. | |
548 | * To keep the length of each row the same, it is padded out with values of -1 | |
549 | * where the search range extends beyond the lines in A. | |
550 | * For example, if max_search_distance_a is 2 and the two sides of a diff chunk | |
551 | * look like this: | |
552 | * a | m | |
553 | * b | n | |
554 | * c | o | |
555 | * d | p | |
556 | * e | q | |
557 | * Then the similarity array will contain: | |
558 | * [-1, -1, am, bm, cm, | |
559 | * -1, an, bn, cn, dn, | |
560 | * ao, bo, co, do, eo, | |
561 | * bp, cp, dp, ep, -1, | |
562 | * cq, dq, eq, -1, -1] | |
563 | * Where similarities are denoted either by -1 for invalid, or the | |
564 | * concatenation of the two lines in the diff being compared. | |
565 | * | |
566 | * \param similarities array of similarities between lines in A and B | |
567 | * \param line_a the index of the line in A, in the same frame of reference as | |
568 | * closest_line_a. | |
569 | * \param local_line_b the index of the line in B, relative to the first line | |
570 | * in B that similarities represents. | |
571 | * \param closest_line_a the index of the line in A that is deemed to be | |
572 | * closest to local_line_b. This must be in the same | |
573 | * frame of reference as line_a. This value defines | |
574 | * where similarities is centered for the line in B. | |
575 | * \param max_search_distance_a maximum distance in lines from the closest line | |
576 | * in A for other lines in A for which | |
577 | * similarities may be calculated. | |
578 | */ | |
579 | static int *get_similarity(int *similarities, | |
580 | int line_a, int local_line_b, | |
581 | int closest_line_a, int max_search_distance_a) | |
582 | { | |
583 | assert(abs(line_a - closest_line_a) <= | |
584 | max_search_distance_a); | |
585 | return similarities + line_a - closest_line_a + | |
586 | max_search_distance_a + | |
587 | local_line_b * (max_search_distance_a * 2 + 1); | |
588 | } | |
589 | ||
590 | #define CERTAIN_NOTHING_MATCHES -2 | |
591 | #define CERTAINTY_NOT_CALCULATED -1 | |
592 | ||
593 | /* Given a line in B, first calculate its similarities with nearby lines in A | |
594 | * if not already calculated, then identify the most similar and second most | |
595 | * similar lines. The "certainty" is calculated based on those two | |
596 | * similarities. | |
597 | * | |
598 | * \param start_a the index of the first line of the chunk in A | |
599 | * \param length_a the length in lines of the chunk in A | |
600 | * \param local_line_b the index of the line in B, relative to the first line | |
601 | * in the chunk. | |
602 | * \param fingerprints_a array of fingerprints for the chunk in A | |
603 | * \param fingerprints_b array of fingerprints for the chunk in B | |
604 | * \param similarities 2-dimensional array of similarities between lines in A | |
605 | * and B. See get_similarity() for more details. | |
606 | * \param certainties array of values indicating how strongly a line in B is | |
607 | * matched with some line in A. | |
608 | * \param second_best_result array of absolute indices in A for the second | |
609 | * closest match of a line in B. | |
610 | * \param result array of absolute indices in A for the closest match of a line | |
611 | * in B. | |
612 | * \param max_search_distance_a maximum distance in lines from the closest line | |
613 | * in A for other lines in A for which | |
614 | * similarities may be calculated. | |
615 | * \param map_line_number_in_b_to_a parameter to map_line_number(). | |
616 | */ | |
617 | static void find_best_line_matches( | |
618 | int start_a, | |
619 | int length_a, | |
620 | int start_b, | |
621 | int local_line_b, | |
622 | struct fingerprint *fingerprints_a, | |
623 | struct fingerprint *fingerprints_b, | |
624 | int *similarities, | |
625 | int *certainties, | |
626 | int *second_best_result, | |
627 | int *result, | |
628 | const int max_search_distance_a, | |
629 | const struct line_number_mapping *map_line_number_in_b_to_a) | |
630 | { | |
631 | ||
632 | int i, search_start, search_end, closest_local_line_a, *similarity, | |
633 | best_similarity = 0, second_best_similarity = 0, | |
634 | best_similarity_index = 0, second_best_similarity_index = 0; | |
635 | ||
636 | /* certainty has already been calculated so no need to redo the work */ | |
637 | if (certainties[local_line_b] != CERTAINTY_NOT_CALCULATED) | |
638 | return; | |
639 | ||
640 | closest_local_line_a = map_line_number( | |
641 | local_line_b + start_b, map_line_number_in_b_to_a) - start_a; | |
642 | ||
643 | search_start = closest_local_line_a - max_search_distance_a; | |
644 | if (search_start < 0) | |
645 | search_start = 0; | |
646 | ||
647 | search_end = closest_local_line_a + max_search_distance_a + 1; | |
648 | if (search_end > length_a) | |
649 | search_end = length_a; | |
650 | ||
651 | for (i = search_start; i < search_end; ++i) { | |
652 | similarity = get_similarity(similarities, | |
653 | i, local_line_b, | |
654 | closest_local_line_a, | |
655 | max_search_distance_a); | |
656 | if (*similarity == -1) { | |
657 | /* This value will never exceed 10 but assert just in | |
658 | * case | |
659 | */ | |
660 | assert(abs(i - closest_local_line_a) < 1000); | |
661 | /* scale the similarity by (1000 - distance from | |
662 | * closest line) to act as a tie break between lines | |
663 | * that otherwise are equally similar. | |
664 | */ | |
665 | *similarity = fingerprint_similarity( | |
666 | fingerprints_b + local_line_b, | |
667 | fingerprints_a + i) * | |
668 | (1000 - abs(i - closest_local_line_a)); | |
669 | } | |
670 | if (*similarity > best_similarity) { | |
671 | second_best_similarity = best_similarity; | |
672 | second_best_similarity_index = best_similarity_index; | |
673 | best_similarity = *similarity; | |
674 | best_similarity_index = i; | |
675 | } else if (*similarity > second_best_similarity) { | |
676 | second_best_similarity = *similarity; | |
677 | second_best_similarity_index = i; | |
678 | } | |
679 | } | |
680 | ||
681 | if (best_similarity == 0) { | |
682 | /* this line definitely doesn't match with anything. Mark it | |
683 | * with this special value so it doesn't get invalidated and | |
684 | * won't be recalculated. | |
685 | */ | |
686 | certainties[local_line_b] = CERTAIN_NOTHING_MATCHES; | |
687 | result[local_line_b] = -1; | |
688 | } else { | |
689 | /* Calculate the certainty with which this line matches. | |
690 | * If the line matches well with two lines then that reduces | |
691 | * the certainty. However we still want to prioritise matching | |
692 | * a line that matches very well with two lines over matching a | |
693 | * line that matches poorly with one line, hence doubling | |
694 | * best_similarity. | |
695 | * This means that if we have | |
696 | * line X that matches only one line with a score of 3, | |
697 | * line Y that matches two lines equally with a score of 5, | |
698 | * and line Z that matches only one line with a score or 2, | |
699 | * then the lines in order of certainty are X, Y, Z. | |
700 | */ | |
701 | certainties[local_line_b] = best_similarity * 2 - | |
702 | second_best_similarity; | |
703 | ||
704 | /* We keep both the best and second best results to allow us to | |
705 | * check at a later stage of the matching process whether the | |
706 | * result needs to be invalidated. | |
707 | */ | |
708 | result[local_line_b] = start_a + best_similarity_index; | |
709 | second_best_result[local_line_b] = | |
710 | start_a + second_best_similarity_index; | |
711 | } | |
712 | } | |
713 | ||
714 | /* | |
715 | * This finds the line that we can match with the most confidence, and | |
716 | * uses it as a partition. It then calls itself on the lines on either side of | |
717 | * that partition. In this way we avoid lines appearing out of order, and | |
718 | * retain a sensible line ordering. | |
719 | * \param start_a index of the first line in A with which lines in B may be | |
720 | * compared. | |
721 | * \param start_b index of the first line in B for which matching should be | |
722 | * done. | |
723 | * \param length_a number of lines in A with which lines in B may be compared. | |
724 | * \param length_b number of lines in B for which matching should be done. | |
725 | * \param fingerprints_a mutable array of fingerprints in A. The first element | |
726 | * corresponds to the line at start_a. | |
727 | * \param fingerprints_b array of fingerprints in B. The first element | |
728 | * corresponds to the line at start_b. | |
729 | * \param similarities 2-dimensional array of similarities between lines in A | |
730 | * and B. See get_similarity() for more details. | |
731 | * \param certainties array of values indicating how strongly a line in B is | |
732 | * matched with some line in A. | |
733 | * \param second_best_result array of absolute indices in A for the second | |
734 | * closest match of a line in B. | |
735 | * \param result array of absolute indices in A for the closest match of a line | |
736 | * in B. | |
737 | * \param max_search_distance_a maximum distance in lines from the closest line | |
738 | * in A for other lines in A for which | |
739 | * similarities may be calculated. | |
740 | * \param max_search_distance_b an upper bound on the greatest possible | |
741 | * distance between lines in B such that they will | |
742 | * both be compared with the same line in A | |
743 | * according to max_search_distance_a. | |
744 | * \param map_line_number_in_b_to_a parameter to map_line_number(). | |
745 | */ | |
746 | static void fuzzy_find_matching_lines_recurse( | |
747 | int start_a, int start_b, | |
748 | int length_a, int length_b, | |
749 | struct fingerprint *fingerprints_a, | |
750 | struct fingerprint *fingerprints_b, | |
751 | int *similarities, | |
752 | int *certainties, | |
753 | int *second_best_result, | |
754 | int *result, | |
755 | int max_search_distance_a, | |
756 | int max_search_distance_b, | |
757 | const struct line_number_mapping *map_line_number_in_b_to_a) | |
758 | { | |
759 | int i, invalidate_min, invalidate_max, offset_b, | |
760 | second_half_start_a, second_half_start_b, | |
761 | second_half_length_a, second_half_length_b, | |
762 | most_certain_line_a, most_certain_local_line_b = -1, | |
763 | most_certain_line_certainty = -1, | |
764 | closest_local_line_a; | |
765 | ||
766 | for (i = 0; i < length_b; ++i) { | |
767 | find_best_line_matches(start_a, | |
768 | length_a, | |
769 | start_b, | |
770 | i, | |
771 | fingerprints_a, | |
772 | fingerprints_b, | |
773 | similarities, | |
774 | certainties, | |
775 | second_best_result, | |
776 | result, | |
777 | max_search_distance_a, | |
778 | map_line_number_in_b_to_a); | |
779 | ||
780 | if (certainties[i] > most_certain_line_certainty) { | |
781 | most_certain_line_certainty = certainties[i]; | |
782 | most_certain_local_line_b = i; | |
783 | } | |
784 | } | |
785 | ||
786 | /* No matches. */ | |
787 | if (most_certain_local_line_b == -1) | |
788 | return; | |
789 | ||
790 | most_certain_line_a = result[most_certain_local_line_b]; | |
791 | ||
792 | /* | |
793 | * Subtract the most certain line's fingerprint in B from the matched | |
794 | * fingerprint in A. This means that other lines in B can't also match | |
795 | * the same parts of the line in A. | |
796 | */ | |
797 | fingerprint_subtract(fingerprints_a + most_certain_line_a - start_a, | |
798 | fingerprints_b + most_certain_local_line_b); | |
799 | ||
800 | /* Invalidate results that may be affected by the choice of most | |
801 | * certain line. | |
802 | */ | |
803 | invalidate_min = most_certain_local_line_b - max_search_distance_b; | |
804 | invalidate_max = most_certain_local_line_b + max_search_distance_b + 1; | |
805 | if (invalidate_min < 0) | |
806 | invalidate_min = 0; | |
807 | if (invalidate_max > length_b) | |
808 | invalidate_max = length_b; | |
809 | ||
810 | /* As the fingerprint in A has changed, discard previously calculated | |
811 | * similarity values with that fingerprint. | |
812 | */ | |
813 | for (i = invalidate_min; i < invalidate_max; ++i) { | |
814 | closest_local_line_a = map_line_number( | |
815 | i + start_b, map_line_number_in_b_to_a) - start_a; | |
816 | ||
817 | /* Check that the lines in A and B are close enough that there | |
818 | * is a similarity value for them. | |
819 | */ | |
820 | if (abs(most_certain_line_a - start_a - closest_local_line_a) > | |
821 | max_search_distance_a) { | |
822 | continue; | |
823 | } | |
824 | ||
825 | *get_similarity(similarities, most_certain_line_a - start_a, | |
826 | i, closest_local_line_a, | |
827 | max_search_distance_a) = -1; | |
828 | } | |
829 | ||
830 | /* More invalidating of results that may be affected by the choice of | |
831 | * most certain line. | |
832 | * Discard the matches for lines in B that are currently matched with a | |
833 | * line in A such that their ordering contradicts the ordering imposed | |
834 | * by the choice of most certain line. | |
835 | */ | |
836 | for (i = most_certain_local_line_b - 1; i >= invalidate_min; --i) { | |
837 | /* In this loop we discard results for lines in B that are | |
838 | * before most-certain-line-B but are matched with a line in A | |
839 | * that is after most-certain-line-A. | |
840 | */ | |
841 | if (certainties[i] >= 0 && | |
842 | (result[i] >= most_certain_line_a || | |
843 | second_best_result[i] >= most_certain_line_a)) { | |
844 | certainties[i] = CERTAINTY_NOT_CALCULATED; | |
845 | } | |
846 | } | |
847 | for (i = most_certain_local_line_b + 1; i < invalidate_max; ++i) { | |
848 | /* In this loop we discard results for lines in B that are | |
849 | * after most-certain-line-B but are matched with a line in A | |
850 | * that is before most-certain-line-A. | |
851 | */ | |
852 | if (certainties[i] >= 0 && | |
853 | (result[i] <= most_certain_line_a || | |
854 | second_best_result[i] <= most_certain_line_a)) { | |
855 | certainties[i] = CERTAINTY_NOT_CALCULATED; | |
856 | } | |
857 | } | |
858 | ||
859 | /* Repeat the matching process for lines before the most certain line. | |
860 | */ | |
861 | if (most_certain_local_line_b > 0) { | |
862 | fuzzy_find_matching_lines_recurse( | |
863 | start_a, start_b, | |
864 | most_certain_line_a + 1 - start_a, | |
865 | most_certain_local_line_b, | |
866 | fingerprints_a, fingerprints_b, similarities, | |
867 | certainties, second_best_result, result, | |
868 | max_search_distance_a, | |
869 | max_search_distance_b, | |
870 | map_line_number_in_b_to_a); | |
871 | } | |
872 | /* Repeat the matching process for lines after the most certain line. | |
873 | */ | |
874 | if (most_certain_local_line_b + 1 < length_b) { | |
875 | second_half_start_a = most_certain_line_a; | |
876 | offset_b = most_certain_local_line_b + 1; | |
877 | second_half_start_b = start_b + offset_b; | |
878 | second_half_length_a = | |
879 | length_a + start_a - second_half_start_a; | |
880 | second_half_length_b = | |
881 | length_b + start_b - second_half_start_b; | |
882 | fuzzy_find_matching_lines_recurse( | |
883 | second_half_start_a, second_half_start_b, | |
884 | second_half_length_a, second_half_length_b, | |
885 | fingerprints_a + second_half_start_a - start_a, | |
886 | fingerprints_b + offset_b, | |
887 | similarities + | |
888 | offset_b * (max_search_distance_a * 2 + 1), | |
889 | certainties + offset_b, | |
890 | second_best_result + offset_b, result + offset_b, | |
891 | max_search_distance_a, | |
892 | max_search_distance_b, | |
893 | map_line_number_in_b_to_a); | |
894 | } | |
895 | } | |
896 | ||
897 | /* Find the lines in the parent line range that most closely match the lines in | |
898 | * the target line range. This is accomplished by matching fingerprints in each | |
899 | * blame_origin, and choosing the best matches that preserve the line ordering. | |
900 | * See struct fingerprint for details of fingerprint matching, and | |
901 | * fuzzy_find_matching_lines_recurse for details of preserving line ordering. | |
902 | * | |
903 | * The performance is believed to be O(n log n) in the typical case and O(n^2) | |
904 | * in a pathological case, where n is the number of lines in the target range. | |
905 | */ | |
906 | static int *fuzzy_find_matching_lines(struct blame_origin *parent, | |
907 | struct blame_origin *target, | |
908 | int tlno, int parent_slno, int same, | |
909 | int parent_len) | |
910 | { | |
911 | /* We use the terminology "A" for the left hand side of the diff AKA | |
912 | * parent, and "B" for the right hand side of the diff AKA target. */ | |
913 | int start_a = parent_slno; | |
914 | int length_a = parent_len; | |
915 | int start_b = tlno; | |
916 | int length_b = same - tlno; | |
917 | ||
918 | struct line_number_mapping map_line_number_in_b_to_a = { | |
919 | start_a, length_a, start_b, length_b | |
920 | }; | |
921 | ||
922 | struct fingerprint *fingerprints_a = parent->fingerprints; | |
923 | struct fingerprint *fingerprints_b = target->fingerprints; | |
924 | ||
925 | int i, *result, *second_best_result, | |
926 | *certainties, *similarities, similarity_count; | |
927 | ||
928 | /* | |
929 | * max_search_distance_a means that given a line in B, compare it to | |
930 | * the line in A that is closest to its position, and the lines in A | |
931 | * that are no greater than max_search_distance_a lines away from the | |
932 | * closest line in A. | |
933 | * | |
934 | * max_search_distance_b is an upper bound on the greatest possible | |
935 | * distance between lines in B such that they will both be compared | |
936 | * with the same line in A according to max_search_distance_a. | |
937 | */ | |
938 | int max_search_distance_a = 10, max_search_distance_b; | |
939 | ||
940 | if (length_a <= 0) | |
941 | return NULL; | |
942 | ||
943 | if (max_search_distance_a >= length_a) | |
944 | max_search_distance_a = length_a ? length_a - 1 : 0; | |
945 | ||
946 | max_search_distance_b = ((2 * max_search_distance_a + 1) * length_b | |
947 | - 1) / length_a; | |
948 | ||
949 | result = xcalloc(sizeof(int), length_b); | |
950 | second_best_result = xcalloc(sizeof(int), length_b); | |
951 | certainties = xcalloc(sizeof(int), length_b); | |
952 | ||
953 | /* See get_similarity() for details of similarities. */ | |
954 | similarity_count = length_b * (max_search_distance_a * 2 + 1); | |
955 | similarities = xcalloc(sizeof(int), similarity_count); | |
956 | ||
957 | for (i = 0; i < length_b; ++i) { | |
958 | result[i] = -1; | |
959 | second_best_result[i] = -1; | |
960 | certainties[i] = CERTAINTY_NOT_CALCULATED; | |
961 | } | |
962 | ||
963 | for (i = 0; i < similarity_count; ++i) | |
964 | similarities[i] = -1; | |
965 | ||
966 | fuzzy_find_matching_lines_recurse(start_a, start_b, | |
967 | length_a, length_b, | |
968 | fingerprints_a + start_a, | |
969 | fingerprints_b + start_b, | |
970 | similarities, | |
971 | certainties, | |
972 | second_best_result, | |
973 | result, | |
974 | max_search_distance_a, | |
975 | max_search_distance_b, | |
976 | &map_line_number_in_b_to_a); | |
977 | ||
978 | free(similarities); | |
979 | free(certainties); | |
980 | free(second_best_result); | |
981 | ||
982 | return result; | |
983 | } | |
984 | ||
985 | static void fill_origin_fingerprints(struct blame_origin *o) | |
986 | { | |
987 | int *line_starts; | |
988 | ||
989 | if (o->fingerprints) | |
990 | return; | |
991 | o->num_lines = find_line_starts(&line_starts, o->file.ptr, | |
992 | o->file.size); | |
993 | o->fingerprints = xcalloc(sizeof(struct fingerprint), o->num_lines); | |
994 | get_line_fingerprints(o->fingerprints, o->file.ptr, line_starts, | |
995 | 0, o->num_lines); | |
996 | free(line_starts); | |
997 | } | |
998 | ||
999 | static void drop_origin_fingerprints(struct blame_origin *o) | |
1000 | { | |
1001 | if (o->fingerprints) { | |
1002 | free_line_fingerprints(o->fingerprints, o->num_lines); | |
1003 | o->num_lines = 0; | |
1004 | FREE_AND_NULL(o->fingerprints); | |
1005 | } | |
1006 | } | |
1007 | ||
1008 | /* | |
1009 | * Given an origin, prepare mmfile_t structure to be used by the | |
1010 | * diff machinery | |
1011 | */ | |
1012 | static void fill_origin_blob(struct diff_options *opt, | |
1013 | struct blame_origin *o, mmfile_t *file, | |
1014 | int *num_read_blob, int fill_fingerprints) | |
1015 | { | |
1016 | if (!o->file.ptr) { | |
1017 | enum object_type type; | |
1018 | unsigned long file_size; | |
1019 | ||
1020 | (*num_read_blob)++; | |
1021 | if (opt->flags.allow_textconv && | |
1022 | textconv_object(opt->repo, o->path, o->mode, | |
1023 | &o->blob_oid, 1, &file->ptr, &file_size)) | |
1024 | ; | |
1025 | else | |
1026 | file->ptr = read_object_file(&o->blob_oid, &type, | |
1027 | &file_size); | |
1028 | file->size = file_size; | |
1029 | ||
1030 | if (!file->ptr) | |
1031 | die("Cannot read blob %s for path %s", | |
1032 | oid_to_hex(&o->blob_oid), | |
1033 | o->path); | |
1034 | o->file = *file; | |
1035 | } | |
1036 | else | |
1037 | *file = o->file; | |
1038 | if (fill_fingerprints) | |
1039 | fill_origin_fingerprints(o); | |
1040 | } | |
1041 | ||
1042 | static void drop_origin_blob(struct blame_origin *o) | |
1043 | { | |
1044 | FREE_AND_NULL(o->file.ptr); | |
1045 | drop_origin_fingerprints(o); | |
1046 | } | |
1047 | ||
1048 | /* | |
1049 | * Any merge of blames happens on lists of blames that arrived via | |
1050 | * different parents in a single suspect. In this case, we want to | |
1051 | * sort according to the suspect line numbers as opposed to the final | |
1052 | * image line numbers. The function body is somewhat longish because | |
1053 | * it avoids unnecessary writes. | |
1054 | */ | |
1055 | ||
1056 | static struct blame_entry *blame_merge(struct blame_entry *list1, | |
1057 | struct blame_entry *list2) | |
1058 | { | |
1059 | struct blame_entry *p1 = list1, *p2 = list2, | |
1060 | **tail = &list1; | |
1061 | ||
1062 | if (!p1) | |
1063 | return p2; | |
1064 | if (!p2) | |
1065 | return p1; | |
1066 | ||
1067 | if (p1->s_lno <= p2->s_lno) { | |
1068 | do { | |
1069 | tail = &p1->next; | |
1070 | if ((p1 = *tail) == NULL) { | |
1071 | *tail = p2; | |
1072 | return list1; | |
1073 | } | |
1074 | } while (p1->s_lno <= p2->s_lno); | |
1075 | } | |
1076 | for (;;) { | |
1077 | *tail = p2; | |
1078 | do { | |
1079 | tail = &p2->next; | |
1080 | if ((p2 = *tail) == NULL) { | |
1081 | *tail = p1; | |
1082 | return list1; | |
1083 | } | |
1084 | } while (p1->s_lno > p2->s_lno); | |
1085 | *tail = p1; | |
1086 | do { | |
1087 | tail = &p1->next; | |
1088 | if ((p1 = *tail) == NULL) { | |
1089 | *tail = p2; | |
1090 | return list1; | |
1091 | } | |
1092 | } while (p1->s_lno <= p2->s_lno); | |
1093 | } | |
1094 | } | |
1095 | ||
1096 | static void *get_next_blame(const void *p) | |
1097 | { | |
1098 | return ((struct blame_entry *)p)->next; | |
1099 | } | |
1100 | ||
1101 | static void set_next_blame(void *p1, void *p2) | |
1102 | { | |
1103 | ((struct blame_entry *)p1)->next = p2; | |
1104 | } | |
1105 | ||
1106 | /* | |
1107 | * Final image line numbers are all different, so we don't need a | |
1108 | * three-way comparison here. | |
1109 | */ | |
1110 | ||
1111 | static int compare_blame_final(const void *p1, const void *p2) | |
1112 | { | |
1113 | return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno | |
1114 | ? 1 : -1; | |
1115 | } | |
1116 | ||
1117 | static int compare_blame_suspect(const void *p1, const void *p2) | |
1118 | { | |
1119 | const struct blame_entry *s1 = p1, *s2 = p2; | |
1120 | /* | |
1121 | * to allow for collating suspects, we sort according to the | |
1122 | * respective pointer value as the primary sorting criterion. | |
1123 | * The actual relation is pretty unimportant as long as it | |
1124 | * establishes a total order. Comparing as integers gives us | |
1125 | * that. | |
1126 | */ | |
1127 | if (s1->suspect != s2->suspect) | |
1128 | return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1; | |
1129 | if (s1->s_lno == s2->s_lno) | |
1130 | return 0; | |
1131 | return s1->s_lno > s2->s_lno ? 1 : -1; | |
1132 | } | |
1133 | ||
1134 | void blame_sort_final(struct blame_scoreboard *sb) | |
1135 | { | |
1136 | sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame, | |
1137 | compare_blame_final); | |
1138 | } | |
1139 | ||
1140 | static int compare_commits_by_reverse_commit_date(const void *a, | |
1141 | const void *b, | |
1142 | void *c) | |
1143 | { | |
1144 | return -compare_commits_by_commit_date(a, b, c); | |
1145 | } | |
1146 | ||
1147 | /* | |
1148 | * For debugging -- origin is refcounted, and this asserts that | |
1149 | * we do not underflow. | |
1150 | */ | |
1151 | static void sanity_check_refcnt(struct blame_scoreboard *sb) | |
1152 | { | |
1153 | int baa = 0; | |
1154 | struct blame_entry *ent; | |
1155 | ||
1156 | for (ent = sb->ent; ent; ent = ent->next) { | |
1157 | /* Nobody should have zero or negative refcnt */ | |
1158 | if (ent->suspect->refcnt <= 0) { | |
1159 | fprintf(stderr, "%s in %s has negative refcnt %d\n", | |
1160 | ent->suspect->path, | |
1161 | oid_to_hex(&ent->suspect->commit->object.oid), | |
1162 | ent->suspect->refcnt); | |
1163 | baa = 1; | |
1164 | } | |
1165 | } | |
1166 | if (baa) | |
1167 | sb->on_sanity_fail(sb, baa); | |
1168 | } | |
1169 | ||
1170 | /* | |
1171 | * If two blame entries that are next to each other came from | |
1172 | * contiguous lines in the same origin (i.e. <commit, path> pair), | |
1173 | * merge them together. | |
1174 | */ | |
1175 | void blame_coalesce(struct blame_scoreboard *sb) | |
1176 | { | |
1177 | struct blame_entry *ent, *next; | |
1178 | ||
1179 | for (ent = sb->ent; ent && (next = ent->next); ent = next) { | |
1180 | if (ent->suspect == next->suspect && | |
1181 | ent->s_lno + ent->num_lines == next->s_lno && | |
1182 | ent->ignored == next->ignored && | |
1183 | ent->unblamable == next->unblamable) { | |
1184 | ent->num_lines += next->num_lines; | |
1185 | ent->next = next->next; | |
1186 | blame_origin_decref(next->suspect); | |
1187 | free(next); | |
1188 | ent->score = 0; | |
1189 | next = ent; /* again */ | |
1190 | } | |
1191 | } | |
1192 | ||
1193 | if (sb->debug) /* sanity */ | |
1194 | sanity_check_refcnt(sb); | |
1195 | } | |
1196 | ||
1197 | /* | |
1198 | * Merge the given sorted list of blames into a preexisting origin. | |
1199 | * If there were no previous blames to that commit, it is entered into | |
1200 | * the commit priority queue of the score board. | |
1201 | */ | |
1202 | ||
1203 | static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin, | |
1204 | struct blame_entry *sorted) | |
1205 | { | |
1206 | if (porigin->suspects) | |
1207 | porigin->suspects = blame_merge(porigin->suspects, sorted); | |
1208 | else { | |
1209 | struct blame_origin *o; | |
1210 | for (o = get_blame_suspects(porigin->commit); o; o = o->next) { | |
1211 | if (o->suspects) { | |
1212 | porigin->suspects = sorted; | |
1213 | return; | |
1214 | } | |
1215 | } | |
1216 | porigin->suspects = sorted; | |
1217 | prio_queue_put(&sb->commits, porigin->commit); | |
1218 | } | |
1219 | } | |
1220 | ||
1221 | /* | |
1222 | * Fill the blob_sha1 field of an origin if it hasn't, so that later | |
1223 | * call to fill_origin_blob() can use it to locate the data. blob_sha1 | |
1224 | * for an origin is also used to pass the blame for the entire file to | |
1225 | * the parent to detect the case where a child's blob is identical to | |
1226 | * that of its parent's. | |
1227 | * | |
1228 | * This also fills origin->mode for corresponding tree path. | |
1229 | */ | |
1230 | static int fill_blob_sha1_and_mode(struct repository *r, | |
1231 | struct blame_origin *origin) | |
1232 | { | |
1233 | if (!is_null_oid(&origin->blob_oid)) | |
1234 | return 0; | |
1235 | if (get_tree_entry(r, &origin->commit->object.oid, origin->path, &origin->blob_oid, &origin->mode)) | |
1236 | goto error_out; | |
1237 | if (oid_object_info(r, &origin->blob_oid, NULL) != OBJ_BLOB) | |
1238 | goto error_out; | |
1239 | return 0; | |
1240 | error_out: | |
1241 | oidclr(&origin->blob_oid); | |
1242 | origin->mode = S_IFINVALID; | |
1243 | return -1; | |
1244 | } | |
1245 | ||
1246 | /* | |
1247 | * We have an origin -- check if the same path exists in the | |
1248 | * parent and return an origin structure to represent it. | |
1249 | */ | |
1250 | static struct blame_origin *find_origin(struct repository *r, | |
1251 | struct commit *parent, | |
1252 | struct blame_origin *origin) | |
1253 | { | |
1254 | struct blame_origin *porigin; | |
1255 | struct diff_options diff_opts; | |
1256 | const char *paths[2]; | |
1257 | ||
1258 | /* First check any existing origins */ | |
1259 | for (porigin = get_blame_suspects(parent); porigin; porigin = porigin->next) | |
1260 | if (!strcmp(porigin->path, origin->path)) { | |
1261 | /* | |
1262 | * The same path between origin and its parent | |
1263 | * without renaming -- the most common case. | |
1264 | */ | |
1265 | return blame_origin_incref (porigin); | |
1266 | } | |
1267 | ||
1268 | /* See if the origin->path is different between parent | |
1269 | * and origin first. Most of the time they are the | |
1270 | * same and diff-tree is fairly efficient about this. | |
1271 | */ | |
1272 | repo_diff_setup(r, &diff_opts); | |
1273 | diff_opts.flags.recursive = 1; | |
1274 | diff_opts.detect_rename = 0; | |
1275 | diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; | |
1276 | paths[0] = origin->path; | |
1277 | paths[1] = NULL; | |
1278 | ||
1279 | parse_pathspec(&diff_opts.pathspec, | |
1280 | PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL, | |
1281 | PATHSPEC_LITERAL_PATH, "", paths); | |
1282 | diff_setup_done(&diff_opts); | |
1283 | ||
1284 | if (is_null_oid(&origin->commit->object.oid)) | |
1285 | do_diff_cache(get_commit_tree_oid(parent), &diff_opts); | |
1286 | else | |
1287 | diff_tree_oid(get_commit_tree_oid(parent), | |
1288 | get_commit_tree_oid(origin->commit), | |
1289 | "", &diff_opts); | |
1290 | diffcore_std(&diff_opts); | |
1291 | ||
1292 | if (!diff_queued_diff.nr) { | |
1293 | /* The path is the same as parent */ | |
1294 | porigin = get_origin(parent, origin->path); | |
1295 | oidcpy(&porigin->blob_oid, &origin->blob_oid); | |
1296 | porigin->mode = origin->mode; | |
1297 | } else { | |
1298 | /* | |
1299 | * Since origin->path is a pathspec, if the parent | |
1300 | * commit had it as a directory, we will see a whole | |
1301 | * bunch of deletion of files in the directory that we | |
1302 | * do not care about. | |
1303 | */ | |
1304 | int i; | |
1305 | struct diff_filepair *p = NULL; | |
1306 | for (i = 0; i < diff_queued_diff.nr; i++) { | |
1307 | const char *name; | |
1308 | p = diff_queued_diff.queue[i]; | |
1309 | name = p->one->path ? p->one->path : p->two->path; | |
1310 | if (!strcmp(name, origin->path)) | |
1311 | break; | |
1312 | } | |
1313 | if (!p) | |
1314 | die("internal error in blame::find_origin"); | |
1315 | switch (p->status) { | |
1316 | default: | |
1317 | die("internal error in blame::find_origin (%c)", | |
1318 | p->status); | |
1319 | case 'M': | |
1320 | porigin = get_origin(parent, origin->path); | |
1321 | oidcpy(&porigin->blob_oid, &p->one->oid); | |
1322 | porigin->mode = p->one->mode; | |
1323 | break; | |
1324 | case 'A': | |
1325 | case 'T': | |
1326 | /* Did not exist in parent, or type changed */ | |
1327 | break; | |
1328 | } | |
1329 | } | |
1330 | diff_flush(&diff_opts); | |
1331 | clear_pathspec(&diff_opts.pathspec); | |
1332 | return porigin; | |
1333 | } | |
1334 | ||
1335 | /* | |
1336 | * We have an origin -- find the path that corresponds to it in its | |
1337 | * parent and return an origin structure to represent it. | |
1338 | */ | |
1339 | static struct blame_origin *find_rename(struct repository *r, | |
1340 | struct commit *parent, | |
1341 | struct blame_origin *origin) | |
1342 | { | |
1343 | struct blame_origin *porigin = NULL; | |
1344 | struct diff_options diff_opts; | |
1345 | int i; | |
1346 | ||
1347 | repo_diff_setup(r, &diff_opts); | |
1348 | diff_opts.flags.recursive = 1; | |
1349 | diff_opts.detect_rename = DIFF_DETECT_RENAME; | |
1350 | diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; | |
1351 | diff_opts.single_follow = origin->path; | |
1352 | diff_setup_done(&diff_opts); | |
1353 | ||
1354 | if (is_null_oid(&origin->commit->object.oid)) | |
1355 | do_diff_cache(get_commit_tree_oid(parent), &diff_opts); | |
1356 | else | |
1357 | diff_tree_oid(get_commit_tree_oid(parent), | |
1358 | get_commit_tree_oid(origin->commit), | |
1359 | "", &diff_opts); | |
1360 | diffcore_std(&diff_opts); | |
1361 | ||
1362 | for (i = 0; i < diff_queued_diff.nr; i++) { | |
1363 | struct diff_filepair *p = diff_queued_diff.queue[i]; | |
1364 | if ((p->status == 'R' || p->status == 'C') && | |
1365 | !strcmp(p->two->path, origin->path)) { | |
1366 | porigin = get_origin(parent, p->one->path); | |
1367 | oidcpy(&porigin->blob_oid, &p->one->oid); | |
1368 | porigin->mode = p->one->mode; | |
1369 | break; | |
1370 | } | |
1371 | } | |
1372 | diff_flush(&diff_opts); | |
1373 | clear_pathspec(&diff_opts.pathspec); | |
1374 | return porigin; | |
1375 | } | |
1376 | ||
1377 | /* | |
1378 | * Append a new blame entry to a given output queue. | |
1379 | */ | |
1380 | static void add_blame_entry(struct blame_entry ***queue, | |
1381 | const struct blame_entry *src) | |
1382 | { | |
1383 | struct blame_entry *e = xmalloc(sizeof(*e)); | |
1384 | memcpy(e, src, sizeof(*e)); | |
1385 | blame_origin_incref(e->suspect); | |
1386 | ||
1387 | e->next = **queue; | |
1388 | **queue = e; | |
1389 | *queue = &e->next; | |
1390 | } | |
1391 | ||
1392 | /* | |
1393 | * src typically is on-stack; we want to copy the information in it to | |
1394 | * a malloced blame_entry that gets added to the given queue. The | |
1395 | * origin of dst loses a refcnt. | |
1396 | */ | |
1397 | static void dup_entry(struct blame_entry ***queue, | |
1398 | struct blame_entry *dst, struct blame_entry *src) | |
1399 | { | |
1400 | blame_origin_incref(src->suspect); | |
1401 | blame_origin_decref(dst->suspect); | |
1402 | memcpy(dst, src, sizeof(*src)); | |
1403 | dst->next = **queue; | |
1404 | **queue = dst; | |
1405 | *queue = &dst->next; | |
1406 | } | |
1407 | ||
1408 | const char *blame_nth_line(struct blame_scoreboard *sb, long lno) | |
1409 | { | |
1410 | return sb->final_buf + sb->lineno[lno]; | |
1411 | } | |
1412 | ||
1413 | /* | |
1414 | * It is known that lines between tlno to same came from parent, and e | |
1415 | * has an overlap with that range. it also is known that parent's | |
1416 | * line plno corresponds to e's line tlno. | |
1417 | * | |
1418 | * <---- e -----> | |
1419 | * <------> | |
1420 | * <------------> | |
1421 | * <------------> | |
1422 | * <------------------> | |
1423 | * | |
1424 | * Split e into potentially three parts; before this chunk, the chunk | |
1425 | * to be blamed for the parent, and after that portion. | |
1426 | */ | |
1427 | static void split_overlap(struct blame_entry *split, | |
1428 | struct blame_entry *e, | |
1429 | int tlno, int plno, int same, | |
1430 | struct blame_origin *parent) | |
1431 | { | |
1432 | int chunk_end_lno; | |
1433 | int i; | |
1434 | memset(split, 0, sizeof(struct blame_entry [3])); | |
1435 | ||
1436 | for (i = 0; i < 3; i++) { | |
1437 | split[i].ignored = e->ignored; | |
1438 | split[i].unblamable = e->unblamable; | |
1439 | } | |
1440 | ||
1441 | if (e->s_lno < tlno) { | |
1442 | /* there is a pre-chunk part not blamed on parent */ | |
1443 | split[0].suspect = blame_origin_incref(e->suspect); | |
1444 | split[0].lno = e->lno; | |
1445 | split[0].s_lno = e->s_lno; | |
1446 | split[0].num_lines = tlno - e->s_lno; | |
1447 | split[1].lno = e->lno + tlno - e->s_lno; | |
1448 | split[1].s_lno = plno; | |
1449 | } | |
1450 | else { | |
1451 | split[1].lno = e->lno; | |
1452 | split[1].s_lno = plno + (e->s_lno - tlno); | |
1453 | } | |
1454 | ||
1455 | if (same < e->s_lno + e->num_lines) { | |
1456 | /* there is a post-chunk part not blamed on parent */ | |
1457 | split[2].suspect = blame_origin_incref(e->suspect); | |
1458 | split[2].lno = e->lno + (same - e->s_lno); | |
1459 | split[2].s_lno = e->s_lno + (same - e->s_lno); | |
1460 | split[2].num_lines = e->s_lno + e->num_lines - same; | |
1461 | chunk_end_lno = split[2].lno; | |
1462 | } | |
1463 | else | |
1464 | chunk_end_lno = e->lno + e->num_lines; | |
1465 | split[1].num_lines = chunk_end_lno - split[1].lno; | |
1466 | ||
1467 | /* | |
1468 | * if it turns out there is nothing to blame the parent for, | |
1469 | * forget about the splitting. !split[1].suspect signals this. | |
1470 | */ | |
1471 | if (split[1].num_lines < 1) | |
1472 | return; | |
1473 | split[1].suspect = blame_origin_incref(parent); | |
1474 | } | |
1475 | ||
1476 | /* | |
1477 | * split_overlap() divided an existing blame e into up to three parts | |
1478 | * in split. Any assigned blame is moved to queue to | |
1479 | * reflect the split. | |
1480 | */ | |
1481 | static void split_blame(struct blame_entry ***blamed, | |
1482 | struct blame_entry ***unblamed, | |
1483 | struct blame_entry *split, | |
1484 | struct blame_entry *e) | |
1485 | { | |
1486 | if (split[0].suspect && split[2].suspect) { | |
1487 | /* The first part (reuse storage for the existing entry e) */ | |
1488 | dup_entry(unblamed, e, &split[0]); | |
1489 | ||
1490 | /* The last part -- me */ | |
1491 | add_blame_entry(unblamed, &split[2]); | |
1492 | ||
1493 | /* ... and the middle part -- parent */ | |
1494 | add_blame_entry(blamed, &split[1]); | |
1495 | } | |
1496 | else if (!split[0].suspect && !split[2].suspect) | |
1497 | /* | |
1498 | * The parent covers the entire area; reuse storage for | |
1499 | * e and replace it with the parent. | |
1500 | */ | |
1501 | dup_entry(blamed, e, &split[1]); | |
1502 | else if (split[0].suspect) { | |
1503 | /* me and then parent */ | |
1504 | dup_entry(unblamed, e, &split[0]); | |
1505 | add_blame_entry(blamed, &split[1]); | |
1506 | } | |
1507 | else { | |
1508 | /* parent and then me */ | |
1509 | dup_entry(blamed, e, &split[1]); | |
1510 | add_blame_entry(unblamed, &split[2]); | |
1511 | } | |
1512 | } | |
1513 | ||
1514 | /* | |
1515 | * After splitting the blame, the origins used by the | |
1516 | * on-stack blame_entry should lose one refcnt each. | |
1517 | */ | |
1518 | static void decref_split(struct blame_entry *split) | |
1519 | { | |
1520 | int i; | |
1521 | ||
1522 | for (i = 0; i < 3; i++) | |
1523 | blame_origin_decref(split[i].suspect); | |
1524 | } | |
1525 | ||
1526 | /* | |
1527 | * reverse_blame reverses the list given in head, appending tail. | |
1528 | * That allows us to build lists in reverse order, then reverse them | |
1529 | * afterwards. This can be faster than building the list in proper | |
1530 | * order right away. The reason is that building in proper order | |
1531 | * requires writing a link in the _previous_ element, while building | |
1532 | * in reverse order just requires placing the list head into the | |
1533 | * _current_ element. | |
1534 | */ | |
1535 | ||
1536 | static struct blame_entry *reverse_blame(struct blame_entry *head, | |
1537 | struct blame_entry *tail) | |
1538 | { | |
1539 | while (head) { | |
1540 | struct blame_entry *next = head->next; | |
1541 | head->next = tail; | |
1542 | tail = head; | |
1543 | head = next; | |
1544 | } | |
1545 | return tail; | |
1546 | } | |
1547 | ||
1548 | /* | |
1549 | * Splits a blame entry into two entries at 'len' lines. The original 'e' | |
1550 | * consists of len lines, i.e. [e->lno, e->lno + len), and the second part, | |
1551 | * which is returned, consists of the remainder: [e->lno + len, e->lno + | |
1552 | * e->num_lines). The caller needs to sort out the reference counting for the | |
1553 | * new entry's suspect. | |
1554 | */ | |
1555 | static struct blame_entry *split_blame_at(struct blame_entry *e, int len, | |
1556 | struct blame_origin *new_suspect) | |
1557 | { | |
1558 | struct blame_entry *n = xcalloc(1, sizeof(struct blame_entry)); | |
1559 | ||
1560 | n->suspect = new_suspect; | |
1561 | n->ignored = e->ignored; | |
1562 | n->unblamable = e->unblamable; | |
1563 | n->lno = e->lno + len; | |
1564 | n->s_lno = e->s_lno + len; | |
1565 | n->num_lines = e->num_lines - len; | |
1566 | e->num_lines = len; | |
1567 | e->score = 0; | |
1568 | return n; | |
1569 | } | |
1570 | ||
1571 | struct blame_line_tracker { | |
1572 | int is_parent; | |
1573 | int s_lno; | |
1574 | }; | |
1575 | ||
1576 | static int are_lines_adjacent(struct blame_line_tracker *first, | |
1577 | struct blame_line_tracker *second) | |
1578 | { | |
1579 | return first->is_parent == second->is_parent && | |
1580 | first->s_lno + 1 == second->s_lno; | |
1581 | } | |
1582 | ||
1583 | static int scan_parent_range(struct fingerprint *p_fps, | |
1584 | struct fingerprint *t_fps, int t_idx, | |
1585 | int from, int nr_lines) | |
1586 | { | |
1587 | int sim, p_idx; | |
1588 | #define FINGERPRINT_FILE_THRESHOLD 10 | |
1589 | int best_sim_val = FINGERPRINT_FILE_THRESHOLD; | |
1590 | int best_sim_idx = -1; | |
1591 | ||
1592 | for (p_idx = from; p_idx < from + nr_lines; p_idx++) { | |
1593 | sim = fingerprint_similarity(&t_fps[t_idx], &p_fps[p_idx]); | |
1594 | if (sim < best_sim_val) | |
1595 | continue; | |
1596 | /* Break ties with the closest-to-target line number */ | |
1597 | if (sim == best_sim_val && best_sim_idx != -1 && | |
1598 | abs(best_sim_idx - t_idx) < abs(p_idx - t_idx)) | |
1599 | continue; | |
1600 | best_sim_val = sim; | |
1601 | best_sim_idx = p_idx; | |
1602 | } | |
1603 | return best_sim_idx; | |
1604 | } | |
1605 | ||
1606 | /* | |
1607 | * The first pass checks the blame entry (from the target) against the parent's | |
1608 | * diff chunk. If that fails for a line, the second pass tries to match that | |
1609 | * line to any part of parent file. That catches cases where a change was | |
1610 | * broken into two chunks by 'context.' | |
1611 | */ | |
1612 | static void guess_line_blames(struct blame_origin *parent, | |
1613 | struct blame_origin *target, | |
1614 | int tlno, int offset, int same, int parent_len, | |
1615 | struct blame_line_tracker *line_blames) | |
1616 | { | |
1617 | int i, best_idx, target_idx; | |
1618 | int parent_slno = tlno + offset; | |
1619 | int *fuzzy_matches; | |
1620 | ||
1621 | fuzzy_matches = fuzzy_find_matching_lines(parent, target, | |
1622 | tlno, parent_slno, same, | |
1623 | parent_len); | |
1624 | for (i = 0; i < same - tlno; i++) { | |
1625 | target_idx = tlno + i; | |
1626 | if (fuzzy_matches && fuzzy_matches[i] >= 0) { | |
1627 | best_idx = fuzzy_matches[i]; | |
1628 | } else { | |
1629 | best_idx = scan_parent_range(parent->fingerprints, | |
1630 | target->fingerprints, | |
1631 | target_idx, 0, | |
1632 | parent->num_lines); | |
1633 | } | |
1634 | if (best_idx >= 0) { | |
1635 | line_blames[i].is_parent = 1; | |
1636 | line_blames[i].s_lno = best_idx; | |
1637 | } else { | |
1638 | line_blames[i].is_parent = 0; | |
1639 | line_blames[i].s_lno = target_idx; | |
1640 | } | |
1641 | } | |
1642 | free(fuzzy_matches); | |
1643 | } | |
1644 | ||
1645 | /* | |
1646 | * This decides which parts of a blame entry go to the parent (added to the | |
1647 | * ignoredp list) and which stay with the target (added to the diffp list). The | |
1648 | * actual decision was made in a separate heuristic function, and those answers | |
1649 | * for the lines in 'e' are in line_blames. This consumes e, essentially | |
1650 | * putting it on a list. | |
1651 | * | |
1652 | * Note that the blame entries on the ignoredp list are not necessarily sorted | |
1653 | * with respect to the parent's line numbers yet. | |
1654 | */ | |
1655 | static void ignore_blame_entry(struct blame_entry *e, | |
1656 | struct blame_origin *parent, | |
1657 | struct blame_entry **diffp, | |
1658 | struct blame_entry **ignoredp, | |
1659 | struct blame_line_tracker *line_blames) | |
1660 | { | |
1661 | int entry_len, nr_lines, i; | |
1662 | ||
1663 | /* | |
1664 | * We carve new entries off the front of e. Each entry comes from a | |
1665 | * contiguous chunk of lines: adjacent lines from the same origin | |
1666 | * (either the parent or the target). | |
1667 | */ | |
1668 | entry_len = 1; | |
1669 | nr_lines = e->num_lines; /* e changes in the loop */ | |
1670 | for (i = 0; i < nr_lines; i++) { | |
1671 | struct blame_entry *next = NULL; | |
1672 | ||
1673 | /* | |
1674 | * We are often adjacent to the next line - only split the blame | |
1675 | * entry when we have to. | |
1676 | */ | |
1677 | if (i + 1 < nr_lines) { | |
1678 | if (are_lines_adjacent(&line_blames[i], | |
1679 | &line_blames[i + 1])) { | |
1680 | entry_len++; | |
1681 | continue; | |
1682 | } | |
1683 | next = split_blame_at(e, entry_len, | |
1684 | blame_origin_incref(e->suspect)); | |
1685 | } | |
1686 | if (line_blames[i].is_parent) { | |
1687 | e->ignored = 1; | |
1688 | blame_origin_decref(e->suspect); | |
1689 | e->suspect = blame_origin_incref(parent); | |
1690 | e->s_lno = line_blames[i - entry_len + 1].s_lno; | |
1691 | e->next = *ignoredp; | |
1692 | *ignoredp = e; | |
1693 | } else { | |
1694 | e->unblamable = 1; | |
1695 | /* e->s_lno is already in the target's address space. */ | |
1696 | e->next = *diffp; | |
1697 | *diffp = e; | |
1698 | } | |
1699 | assert(e->num_lines == entry_len); | |
1700 | e = next; | |
1701 | entry_len = 1; | |
1702 | } | |
1703 | assert(!e); | |
1704 | } | |
1705 | ||
1706 | /* | |
1707 | * Process one hunk from the patch between the current suspect for | |
1708 | * blame_entry e and its parent. This first blames any unfinished | |
1709 | * entries before the chunk (which is where target and parent start | |
1710 | * differing) on the parent, and then splits blame entries at the | |
1711 | * start and at the end of the difference region. Since use of -M and | |
1712 | * -C options may lead to overlapping/duplicate source line number | |
1713 | * ranges, all we can rely on from sorting/merging is the order of the | |
1714 | * first suspect line number. | |
1715 | * | |
1716 | * tlno: line number in the target where this chunk begins | |
1717 | * same: line number in the target where this chunk ends | |
1718 | * offset: add to tlno to get the chunk starting point in the parent | |
1719 | * parent_len: number of lines in the parent chunk | |
1720 | */ | |
1721 | static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq, | |
1722 | int tlno, int offset, int same, int parent_len, | |
1723 | struct blame_origin *parent, | |
1724 | struct blame_origin *target, int ignore_diffs) | |
1725 | { | |
1726 | struct blame_entry *e = **srcq; | |
1727 | struct blame_entry *samep = NULL, *diffp = NULL, *ignoredp = NULL; | |
1728 | struct blame_line_tracker *line_blames = NULL; | |
1729 | ||
1730 | while (e && e->s_lno < tlno) { | |
1731 | struct blame_entry *next = e->next; | |
1732 | /* | |
1733 | * current record starts before differing portion. If | |
1734 | * it reaches into it, we need to split it up and | |
1735 | * examine the second part separately. | |
1736 | */ | |
1737 | if (e->s_lno + e->num_lines > tlno) { | |
1738 | /* Move second half to a new record */ | |
1739 | struct blame_entry *n; | |
1740 | ||
1741 | n = split_blame_at(e, tlno - e->s_lno, e->suspect); | |
1742 | /* Push new record to diffp */ | |
1743 | n->next = diffp; | |
1744 | diffp = n; | |
1745 | } else | |
1746 | blame_origin_decref(e->suspect); | |
1747 | /* Pass blame for everything before the differing | |
1748 | * chunk to the parent */ | |
1749 | e->suspect = blame_origin_incref(parent); | |
1750 | e->s_lno += offset; | |
1751 | e->next = samep; | |
1752 | samep = e; | |
1753 | e = next; | |
1754 | } | |
1755 | /* | |
1756 | * As we don't know how much of a common stretch after this | |
1757 | * diff will occur, the currently blamed parts are all that we | |
1758 | * can assign to the parent for now. | |
1759 | */ | |
1760 | ||
1761 | if (samep) { | |
1762 | **dstq = reverse_blame(samep, **dstq); | |
1763 | *dstq = &samep->next; | |
1764 | } | |
1765 | /* | |
1766 | * Prepend the split off portions: everything after e starts | |
1767 | * after the blameable portion. | |
1768 | */ | |
1769 | e = reverse_blame(diffp, e); | |
1770 | ||
1771 | /* | |
1772 | * Now retain records on the target while parts are different | |
1773 | * from the parent. | |
1774 | */ | |
1775 | samep = NULL; | |
1776 | diffp = NULL; | |
1777 | ||
1778 | if (ignore_diffs && same - tlno > 0) { | |
1779 | line_blames = xcalloc(sizeof(struct blame_line_tracker), | |
1780 | same - tlno); | |
1781 | guess_line_blames(parent, target, tlno, offset, same, | |
1782 | parent_len, line_blames); | |
1783 | } | |
1784 | ||
1785 | while (e && e->s_lno < same) { | |
1786 | struct blame_entry *next = e->next; | |
1787 | ||
1788 | /* | |
1789 | * If current record extends into sameness, need to split. | |
1790 | */ | |
1791 | if (e->s_lno + e->num_lines > same) { | |
1792 | /* | |
1793 | * Move second half to a new record to be | |
1794 | * processed by later chunks | |
1795 | */ | |
1796 | struct blame_entry *n; | |
1797 | ||
1798 | n = split_blame_at(e, same - e->s_lno, | |
1799 | blame_origin_incref(e->suspect)); | |
1800 | /* Push new record to samep */ | |
1801 | n->next = samep; | |
1802 | samep = n; | |
1803 | } | |
1804 | if (ignore_diffs) { | |
1805 | ignore_blame_entry(e, parent, &diffp, &ignoredp, | |
1806 | line_blames + e->s_lno - tlno); | |
1807 | } else { | |
1808 | e->next = diffp; | |
1809 | diffp = e; | |
1810 | } | |
1811 | e = next; | |
1812 | } | |
1813 | free(line_blames); | |
1814 | if (ignoredp) { | |
1815 | /* | |
1816 | * Note ignoredp is not sorted yet, and thus neither is dstq. | |
1817 | * That list must be sorted before we queue_blames(). We defer | |
1818 | * sorting until after all diff hunks are processed, so that | |
1819 | * guess_line_blames() can pick *any* line in the parent. The | |
1820 | * slight drawback is that we end up sorting all blame entries | |
1821 | * passed to the parent, including those that are unrelated to | |
1822 | * changes made by the ignored commit. | |
1823 | */ | |
1824 | **dstq = reverse_blame(ignoredp, **dstq); | |
1825 | *dstq = &ignoredp->next; | |
1826 | } | |
1827 | **srcq = reverse_blame(diffp, reverse_blame(samep, e)); | |
1828 | /* Move across elements that are in the unblamable portion */ | |
1829 | if (diffp) | |
1830 | *srcq = &diffp->next; | |
1831 | } | |
1832 | ||
1833 | struct blame_chunk_cb_data { | |
1834 | struct blame_origin *parent; | |
1835 | struct blame_origin *target; | |
1836 | long offset; | |
1837 | int ignore_diffs; | |
1838 | struct blame_entry **dstq; | |
1839 | struct blame_entry **srcq; | |
1840 | }; | |
1841 | ||
1842 | /* diff chunks are from parent to target */ | |
1843 | static int blame_chunk_cb(long start_a, long count_a, | |
1844 | long start_b, long count_b, void *data) | |
1845 | { | |
1846 | struct blame_chunk_cb_data *d = data; | |
1847 | if (start_a - start_b != d->offset) | |
1848 | die("internal error in blame::blame_chunk_cb"); | |
1849 | blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b, | |
1850 | start_b + count_b, count_a, d->parent, d->target, | |
1851 | d->ignore_diffs); | |
1852 | d->offset = start_a + count_a - (start_b + count_b); | |
1853 | return 0; | |
1854 | } | |
1855 | ||
1856 | /* | |
1857 | * We are looking at the origin 'target' and aiming to pass blame | |
1858 | * for the lines it is suspected to its parent. Run diff to find | |
1859 | * which lines came from parent and pass blame for them. | |
1860 | */ | |
1861 | static void pass_blame_to_parent(struct blame_scoreboard *sb, | |
1862 | struct blame_origin *target, | |
1863 | struct blame_origin *parent, int ignore_diffs) | |
1864 | { | |
1865 | mmfile_t file_p, file_o; | |
1866 | struct blame_chunk_cb_data d; | |
1867 | struct blame_entry *newdest = NULL; | |
1868 | ||
1869 | if (!target->suspects) | |
1870 | return; /* nothing remains for this target */ | |
1871 | ||
1872 | d.parent = parent; | |
1873 | d.target = target; | |
1874 | d.offset = 0; | |
1875 | d.ignore_diffs = ignore_diffs; | |
1876 | d.dstq = &newdest; d.srcq = &target->suspects; | |
1877 | ||
1878 | fill_origin_blob(&sb->revs->diffopt, parent, &file_p, | |
1879 | &sb->num_read_blob, ignore_diffs); | |
1880 | fill_origin_blob(&sb->revs->diffopt, target, &file_o, | |
1881 | &sb->num_read_blob, ignore_diffs); | |
1882 | sb->num_get_patch++; | |
1883 | ||
1884 | if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts)) | |
1885 | die("unable to generate diff (%s -> %s)", | |
1886 | oid_to_hex(&parent->commit->object.oid), | |
1887 | oid_to_hex(&target->commit->object.oid)); | |
1888 | /* The rest are the same as the parent */ | |
1889 | blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, 0, | |
1890 | parent, target, 0); | |
1891 | *d.dstq = NULL; | |
1892 | if (ignore_diffs) | |
1893 | newdest = llist_mergesort(newdest, get_next_blame, | |
1894 | set_next_blame, | |
1895 | compare_blame_suspect); | |
1896 | queue_blames(sb, parent, newdest); | |
1897 | ||
1898 | return; | |
1899 | } | |
1900 | ||
1901 | /* | |
1902 | * The lines in blame_entry after splitting blames many times can become | |
1903 | * very small and trivial, and at some point it becomes pointless to | |
1904 | * blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any | |
1905 | * ordinary C program, and it is not worth to say it was copied from | |
1906 | * totally unrelated file in the parent. | |
1907 | * | |
1908 | * Compute how trivial the lines in the blame_entry are. | |
1909 | */ | |
1910 | unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e) | |
1911 | { | |
1912 | unsigned score; | |
1913 | const char *cp, *ep; | |
1914 | ||
1915 | if (e->score) | |
1916 | return e->score; | |
1917 | ||
1918 | score = 1; | |
1919 | cp = blame_nth_line(sb, e->lno); | |
1920 | ep = blame_nth_line(sb, e->lno + e->num_lines); | |
1921 | while (cp < ep) { | |
1922 | unsigned ch = *((unsigned char *)cp); | |
1923 | if (isalnum(ch)) | |
1924 | score++; | |
1925 | cp++; | |
1926 | } | |
1927 | e->score = score; | |
1928 | return score; | |
1929 | } | |
1930 | ||
1931 | /* | |
1932 | * best_so_far[] and potential[] are both a split of an existing blame_entry | |
1933 | * that passes blame to the parent. Maintain best_so_far the best split so | |
1934 | * far, by comparing potential and best_so_far and copying potential into | |
1935 | * bst_so_far as needed. | |
1936 | */ | |
1937 | static void copy_split_if_better(struct blame_scoreboard *sb, | |
1938 | struct blame_entry *best_so_far, | |
1939 | struct blame_entry *potential) | |
1940 | { | |
1941 | int i; | |
1942 | ||
1943 | if (!potential[1].suspect) | |
1944 | return; | |
1945 | if (best_so_far[1].suspect) { | |
1946 | if (blame_entry_score(sb, &potential[1]) < | |
1947 | blame_entry_score(sb, &best_so_far[1])) | |
1948 | return; | |
1949 | } | |
1950 | ||
1951 | for (i = 0; i < 3; i++) | |
1952 | blame_origin_incref(potential[i].suspect); | |
1953 | decref_split(best_so_far); | |
1954 | memcpy(best_so_far, potential, sizeof(struct blame_entry[3])); | |
1955 | } | |
1956 | ||
1957 | /* | |
1958 | * We are looking at a part of the final image represented by | |
1959 | * ent (tlno and same are offset by ent->s_lno). | |
1960 | * tlno is where we are looking at in the final image. | |
1961 | * up to (but not including) same match preimage. | |
1962 | * plno is where we are looking at in the preimage. | |
1963 | * | |
1964 | * <-------------- final image ----------------------> | |
1965 | * <------ent------> | |
1966 | * ^tlno ^same | |
1967 | * <---------preimage-----> | |
1968 | * ^plno | |
1969 | * | |
1970 | * All line numbers are 0-based. | |
1971 | */ | |
1972 | static void handle_split(struct blame_scoreboard *sb, | |
1973 | struct blame_entry *ent, | |
1974 | int tlno, int plno, int same, | |
1975 | struct blame_origin *parent, | |
1976 | struct blame_entry *split) | |
1977 | { | |
1978 | if (ent->num_lines <= tlno) | |
1979 | return; | |
1980 | if (tlno < same) { | |
1981 | struct blame_entry potential[3]; | |
1982 | tlno += ent->s_lno; | |
1983 | same += ent->s_lno; | |
1984 | split_overlap(potential, ent, tlno, plno, same, parent); | |
1985 | copy_split_if_better(sb, split, potential); | |
1986 | decref_split(potential); | |
1987 | } | |
1988 | } | |
1989 | ||
1990 | struct handle_split_cb_data { | |
1991 | struct blame_scoreboard *sb; | |
1992 | struct blame_entry *ent; | |
1993 | struct blame_origin *parent; | |
1994 | struct blame_entry *split; | |
1995 | long plno; | |
1996 | long tlno; | |
1997 | }; | |
1998 | ||
1999 | static int handle_split_cb(long start_a, long count_a, | |
2000 | long start_b, long count_b, void *data) | |
2001 | { | |
2002 | struct handle_split_cb_data *d = data; | |
2003 | handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent, | |
2004 | d->split); | |
2005 | d->plno = start_a + count_a; | |
2006 | d->tlno = start_b + count_b; | |
2007 | return 0; | |
2008 | } | |
2009 | ||
2010 | /* | |
2011 | * Find the lines from parent that are the same as ent so that | |
2012 | * we can pass blames to it. file_p has the blob contents for | |
2013 | * the parent. | |
2014 | */ | |
2015 | static void find_copy_in_blob(struct blame_scoreboard *sb, | |
2016 | struct blame_entry *ent, | |
2017 | struct blame_origin *parent, | |
2018 | struct blame_entry *split, | |
2019 | mmfile_t *file_p) | |
2020 | { | |
2021 | const char *cp; | |
2022 | mmfile_t file_o; | |
2023 | struct handle_split_cb_data d; | |
2024 | ||
2025 | memset(&d, 0, sizeof(d)); | |
2026 | d.sb = sb; d.ent = ent; d.parent = parent; d.split = split; | |
2027 | /* | |
2028 | * Prepare mmfile that contains only the lines in ent. | |
2029 | */ | |
2030 | cp = blame_nth_line(sb, ent->lno); | |
2031 | file_o.ptr = (char *) cp; | |
2032 | file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp; | |
2033 | ||
2034 | /* | |
2035 | * file_o is a part of final image we are annotating. | |
2036 | * file_p partially may match that image. | |
2037 | */ | |
2038 | memset(split, 0, sizeof(struct blame_entry [3])); | |
2039 | if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts)) | |
2040 | die("unable to generate diff (%s)", | |
2041 | oid_to_hex(&parent->commit->object.oid)); | |
2042 | /* remainder, if any, all match the preimage */ | |
2043 | handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split); | |
2044 | } | |
2045 | ||
2046 | /* Move all blame entries from list *source that have a score smaller | |
2047 | * than score_min to the front of list *small. | |
2048 | * Returns a pointer to the link pointing to the old head of the small list. | |
2049 | */ | |
2050 | ||
2051 | static struct blame_entry **filter_small(struct blame_scoreboard *sb, | |
2052 | struct blame_entry **small, | |
2053 | struct blame_entry **source, | |
2054 | unsigned score_min) | |
2055 | { | |
2056 | struct blame_entry *p = *source; | |
2057 | struct blame_entry *oldsmall = *small; | |
2058 | while (p) { | |
2059 | if (blame_entry_score(sb, p) <= score_min) { | |
2060 | *small = p; | |
2061 | small = &p->next; | |
2062 | p = *small; | |
2063 | } else { | |
2064 | *source = p; | |
2065 | source = &p->next; | |
2066 | p = *source; | |
2067 | } | |
2068 | } | |
2069 | *small = oldsmall; | |
2070 | *source = NULL; | |
2071 | return small; | |
2072 | } | |
2073 | ||
2074 | /* | |
2075 | * See if lines currently target is suspected for can be attributed to | |
2076 | * parent. | |
2077 | */ | |
2078 | static void find_move_in_parent(struct blame_scoreboard *sb, | |
2079 | struct blame_entry ***blamed, | |
2080 | struct blame_entry **toosmall, | |
2081 | struct blame_origin *target, | |
2082 | struct blame_origin *parent) | |
2083 | { | |
2084 | struct blame_entry *e, split[3]; | |
2085 | struct blame_entry *unblamed = target->suspects; | |
2086 | struct blame_entry *leftover = NULL; | |
2087 | mmfile_t file_p; | |
2088 | ||
2089 | if (!unblamed) | |
2090 | return; /* nothing remains for this target */ | |
2091 | ||
2092 | fill_origin_blob(&sb->revs->diffopt, parent, &file_p, | |
2093 | &sb->num_read_blob, 0); | |
2094 | if (!file_p.ptr) | |
2095 | return; | |
2096 | ||
2097 | /* At each iteration, unblamed has a NULL-terminated list of | |
2098 | * entries that have not yet been tested for blame. leftover | |
2099 | * contains the reversed list of entries that have been tested | |
2100 | * without being assignable to the parent. | |
2101 | */ | |
2102 | do { | |
2103 | struct blame_entry **unblamedtail = &unblamed; | |
2104 | struct blame_entry *next; | |
2105 | for (e = unblamed; e; e = next) { | |
2106 | next = e->next; | |
2107 | find_copy_in_blob(sb, e, parent, split, &file_p); | |
2108 | if (split[1].suspect && | |
2109 | sb->move_score < blame_entry_score(sb, &split[1])) { | |
2110 | split_blame(blamed, &unblamedtail, split, e); | |
2111 | } else { | |
2112 | e->next = leftover; | |
2113 | leftover = e; | |
2114 | } | |
2115 | decref_split(split); | |
2116 | } | |
2117 | *unblamedtail = NULL; | |
2118 | toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score); | |
2119 | } while (unblamed); | |
2120 | target->suspects = reverse_blame(leftover, NULL); | |
2121 | } | |
2122 | ||
2123 | struct blame_list { | |
2124 | struct blame_entry *ent; | |
2125 | struct blame_entry split[3]; | |
2126 | }; | |
2127 | ||
2128 | /* | |
2129 | * Count the number of entries the target is suspected for, | |
2130 | * and prepare a list of entry and the best split. | |
2131 | */ | |
2132 | static struct blame_list *setup_blame_list(struct blame_entry *unblamed, | |
2133 | int *num_ents_p) | |
2134 | { | |
2135 | struct blame_entry *e; | |
2136 | int num_ents, i; | |
2137 | struct blame_list *blame_list = NULL; | |
2138 | ||
2139 | for (e = unblamed, num_ents = 0; e; e = e->next) | |
2140 | num_ents++; | |
2141 | if (num_ents) { | |
2142 | blame_list = xcalloc(num_ents, sizeof(struct blame_list)); | |
2143 | for (e = unblamed, i = 0; e; e = e->next) | |
2144 | blame_list[i++].ent = e; | |
2145 | } | |
2146 | *num_ents_p = num_ents; | |
2147 | return blame_list; | |
2148 | } | |
2149 | ||
2150 | /* | |
2151 | * For lines target is suspected for, see if we can find code movement | |
2152 | * across file boundary from the parent commit. porigin is the path | |
2153 | * in the parent we already tried. | |
2154 | */ | |
2155 | static void find_copy_in_parent(struct blame_scoreboard *sb, | |
2156 | struct blame_entry ***blamed, | |
2157 | struct blame_entry **toosmall, | |
2158 | struct blame_origin *target, | |
2159 | struct commit *parent, | |
2160 | struct blame_origin *porigin, | |
2161 | int opt) | |
2162 | { | |
2163 | struct diff_options diff_opts; | |
2164 | int i, j; | |
2165 | struct blame_list *blame_list; | |
2166 | int num_ents; | |
2167 | struct blame_entry *unblamed = target->suspects; | |
2168 | struct blame_entry *leftover = NULL; | |
2169 | ||
2170 | if (!unblamed) | |
2171 | return; /* nothing remains for this target */ | |
2172 | ||
2173 | repo_diff_setup(sb->repo, &diff_opts); | |
2174 | diff_opts.flags.recursive = 1; | |
2175 | diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; | |
2176 | ||
2177 | diff_setup_done(&diff_opts); | |
2178 | ||
2179 | /* Try "find copies harder" on new path if requested; | |
2180 | * we do not want to use diffcore_rename() actually to | |
2181 | * match things up; find_copies_harder is set only to | |
2182 | * force diff_tree_oid() to feed all filepairs to diff_queue, | |
2183 | * and this code needs to be after diff_setup_done(), which | |
2184 | * usually makes find-copies-harder imply copy detection. | |
2185 | */ | |
2186 | if ((opt & PICKAXE_BLAME_COPY_HARDEST) | |
2187 | || ((opt & PICKAXE_BLAME_COPY_HARDER) | |
2188 | && (!porigin || strcmp(target->path, porigin->path)))) | |
2189 | diff_opts.flags.find_copies_harder = 1; | |
2190 | ||
2191 | if (is_null_oid(&target->commit->object.oid)) | |
2192 | do_diff_cache(get_commit_tree_oid(parent), &diff_opts); | |
2193 | else | |
2194 | diff_tree_oid(get_commit_tree_oid(parent), | |
2195 | get_commit_tree_oid(target->commit), | |
2196 | "", &diff_opts); | |
2197 | ||
2198 | if (!diff_opts.flags.find_copies_harder) | |
2199 | diffcore_std(&diff_opts); | |
2200 | ||
2201 | do { | |
2202 | struct blame_entry **unblamedtail = &unblamed; | |
2203 | blame_list = setup_blame_list(unblamed, &num_ents); | |
2204 | ||
2205 | for (i = 0; i < diff_queued_diff.nr; i++) { | |
2206 | struct diff_filepair *p = diff_queued_diff.queue[i]; | |
2207 | struct blame_origin *norigin; | |
2208 | mmfile_t file_p; | |
2209 | struct blame_entry potential[3]; | |
2210 | ||
2211 | if (!DIFF_FILE_VALID(p->one)) | |
2212 | continue; /* does not exist in parent */ | |
2213 | if (S_ISGITLINK(p->one->mode)) | |
2214 | continue; /* ignore git links */ | |
2215 | if (porigin && !strcmp(p->one->path, porigin->path)) | |
2216 | /* find_move already dealt with this path */ | |
2217 | continue; | |
2218 | ||
2219 | norigin = get_origin(parent, p->one->path); | |
2220 | oidcpy(&norigin->blob_oid, &p->one->oid); | |
2221 | norigin->mode = p->one->mode; | |
2222 | fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, | |
2223 | &sb->num_read_blob, 0); | |
2224 | if (!file_p.ptr) | |
2225 | continue; | |
2226 | ||
2227 | for (j = 0; j < num_ents; j++) { | |
2228 | find_copy_in_blob(sb, blame_list[j].ent, | |
2229 | norigin, potential, &file_p); | |
2230 | copy_split_if_better(sb, blame_list[j].split, | |
2231 | potential); | |
2232 | decref_split(potential); | |
2233 | } | |
2234 | blame_origin_decref(norigin); | |
2235 | } | |
2236 | ||
2237 | for (j = 0; j < num_ents; j++) { | |
2238 | struct blame_entry *split = blame_list[j].split; | |
2239 | if (split[1].suspect && | |
2240 | sb->copy_score < blame_entry_score(sb, &split[1])) { | |
2241 | split_blame(blamed, &unblamedtail, split, | |
2242 | blame_list[j].ent); | |
2243 | } else { | |
2244 | blame_list[j].ent->next = leftover; | |
2245 | leftover = blame_list[j].ent; | |
2246 | } | |
2247 | decref_split(split); | |
2248 | } | |
2249 | free(blame_list); | |
2250 | *unblamedtail = NULL; | |
2251 | toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score); | |
2252 | } while (unblamed); | |
2253 | target->suspects = reverse_blame(leftover, NULL); | |
2254 | diff_flush(&diff_opts); | |
2255 | clear_pathspec(&diff_opts.pathspec); | |
2256 | } | |
2257 | ||
2258 | /* | |
2259 | * The blobs of origin and porigin exactly match, so everything | |
2260 | * origin is suspected for can be blamed on the parent. | |
2261 | */ | |
2262 | static void pass_whole_blame(struct blame_scoreboard *sb, | |
2263 | struct blame_origin *origin, struct blame_origin *porigin) | |
2264 | { | |
2265 | struct blame_entry *e, *suspects; | |
2266 | ||
2267 | if (!porigin->file.ptr && origin->file.ptr) { | |
2268 | /* Steal its file */ | |
2269 | porigin->file = origin->file; | |
2270 | origin->file.ptr = NULL; | |
2271 | } | |
2272 | suspects = origin->suspects; | |
2273 | origin->suspects = NULL; | |
2274 | for (e = suspects; e; e = e->next) { | |
2275 | blame_origin_incref(porigin); | |
2276 | blame_origin_decref(e->suspect); | |
2277 | e->suspect = porigin; | |
2278 | } | |
2279 | queue_blames(sb, porigin, suspects); | |
2280 | } | |
2281 | ||
2282 | /* | |
2283 | * We pass blame from the current commit to its parents. We keep saying | |
2284 | * "parent" (and "porigin"), but what we mean is to find scapegoat to | |
2285 | * exonerate ourselves. | |
2286 | */ | |
2287 | static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit, | |
2288 | int reverse) | |
2289 | { | |
2290 | if (!reverse) { | |
2291 | if (revs->first_parent_only && | |
2292 | commit->parents && | |
2293 | commit->parents->next) { | |
2294 | free_commit_list(commit->parents->next); | |
2295 | commit->parents->next = NULL; | |
2296 | } | |
2297 | return commit->parents; | |
2298 | } | |
2299 | return lookup_decoration(&revs->children, &commit->object); | |
2300 | } | |
2301 | ||
2302 | static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse) | |
2303 | { | |
2304 | struct commit_list *l = first_scapegoat(revs, commit, reverse); | |
2305 | return commit_list_count(l); | |
2306 | } | |
2307 | ||
2308 | /* Distribute collected unsorted blames to the respected sorted lists | |
2309 | * in the various origins. | |
2310 | */ | |
2311 | static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed) | |
2312 | { | |
2313 | blamed = llist_mergesort(blamed, get_next_blame, set_next_blame, | |
2314 | compare_blame_suspect); | |
2315 | while (blamed) | |
2316 | { | |
2317 | struct blame_origin *porigin = blamed->suspect; | |
2318 | struct blame_entry *suspects = NULL; | |
2319 | do { | |
2320 | struct blame_entry *next = blamed->next; | |
2321 | blamed->next = suspects; | |
2322 | suspects = blamed; | |
2323 | blamed = next; | |
2324 | } while (blamed && blamed->suspect == porigin); | |
2325 | suspects = reverse_blame(suspects, NULL); | |
2326 | queue_blames(sb, porigin, suspects); | |
2327 | } | |
2328 | } | |
2329 | ||
2330 | #define MAXSG 16 | |
2331 | ||
2332 | static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt) | |
2333 | { | |
2334 | struct rev_info *revs = sb->revs; | |
2335 | int i, pass, num_sg; | |
2336 | struct commit *commit = origin->commit; | |
2337 | struct commit_list *sg; | |
2338 | struct blame_origin *sg_buf[MAXSG]; | |
2339 | struct blame_origin *porigin, **sg_origin = sg_buf; | |
2340 | struct blame_entry *toosmall = NULL; | |
2341 | struct blame_entry *blames, **blametail = &blames; | |
2342 | ||
2343 | num_sg = num_scapegoats(revs, commit, sb->reverse); | |
2344 | if (!num_sg) | |
2345 | goto finish; | |
2346 | else if (num_sg < ARRAY_SIZE(sg_buf)) | |
2347 | memset(sg_buf, 0, sizeof(sg_buf)); | |
2348 | else | |
2349 | sg_origin = xcalloc(num_sg, sizeof(*sg_origin)); | |
2350 | ||
2351 | /* | |
2352 | * The first pass looks for unrenamed path to optimize for | |
2353 | * common cases, then we look for renames in the second pass. | |
2354 | */ | |
2355 | for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) { | |
2356 | struct blame_origin *(*find)(struct repository *, struct commit *, struct blame_origin *); | |
2357 | find = pass ? find_rename : find_origin; | |
2358 | ||
2359 | for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); | |
2360 | i < num_sg && sg; | |
2361 | sg = sg->next, i++) { | |
2362 | struct commit *p = sg->item; | |
2363 | int j, same; | |
2364 | ||
2365 | if (sg_origin[i]) | |
2366 | continue; | |
2367 | if (parse_commit(p)) | |
2368 | continue; | |
2369 | porigin = find(sb->repo, p, origin); | |
2370 | if (!porigin) | |
2371 | continue; | |
2372 | if (oideq(&porigin->blob_oid, &origin->blob_oid)) { | |
2373 | pass_whole_blame(sb, origin, porigin); | |
2374 | blame_origin_decref(porigin); | |
2375 | goto finish; | |
2376 | } | |
2377 | for (j = same = 0; j < i; j++) | |
2378 | if (sg_origin[j] && | |
2379 | oideq(&sg_origin[j]->blob_oid, &porigin->blob_oid)) { | |
2380 | same = 1; | |
2381 | break; | |
2382 | } | |
2383 | if (!same) | |
2384 | sg_origin[i] = porigin; | |
2385 | else | |
2386 | blame_origin_decref(porigin); | |
2387 | } | |
2388 | } | |
2389 | ||
2390 | sb->num_commits++; | |
2391 | for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); | |
2392 | i < num_sg && sg; | |
2393 | sg = sg->next, i++) { | |
2394 | struct blame_origin *porigin = sg_origin[i]; | |
2395 | if (!porigin) | |
2396 | continue; | |
2397 | if (!origin->previous) { | |
2398 | blame_origin_incref(porigin); | |
2399 | origin->previous = porigin; | |
2400 | } | |
2401 | pass_blame_to_parent(sb, origin, porigin, 0); | |
2402 | if (!origin->suspects) | |
2403 | goto finish; | |
2404 | } | |
2405 | ||
2406 | /* | |
2407 | * Pass remaining suspects for ignored commits to their parents. | |
2408 | */ | |
2409 | if (oidset_contains(&sb->ignore_list, &commit->object.oid)) { | |
2410 | for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); | |
2411 | i < num_sg && sg; | |
2412 | sg = sg->next, i++) { | |
2413 | struct blame_origin *porigin = sg_origin[i]; | |
2414 | ||
2415 | if (!porigin) | |
2416 | continue; | |
2417 | pass_blame_to_parent(sb, origin, porigin, 1); | |
2418 | /* | |
2419 | * Preemptively drop porigin so we can refresh the | |
2420 | * fingerprints if we use the parent again, which can | |
2421 | * occur if you ignore back-to-back commits. | |
2422 | */ | |
2423 | drop_origin_blob(porigin); | |
2424 | if (!origin->suspects) | |
2425 | goto finish; | |
2426 | } | |
2427 | } | |
2428 | ||
2429 | /* | |
2430 | * Optionally find moves in parents' files. | |
2431 | */ | |
2432 | if (opt & PICKAXE_BLAME_MOVE) { | |
2433 | filter_small(sb, &toosmall, &origin->suspects, sb->move_score); | |
2434 | if (origin->suspects) { | |
2435 | for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); | |
2436 | i < num_sg && sg; | |
2437 | sg = sg->next, i++) { | |
2438 | struct blame_origin *porigin = sg_origin[i]; | |
2439 | if (!porigin) | |
2440 | continue; | |
2441 | find_move_in_parent(sb, &blametail, &toosmall, origin, porigin); | |
2442 | if (!origin->suspects) | |
2443 | break; | |
2444 | } | |
2445 | } | |
2446 | } | |
2447 | ||
2448 | /* | |
2449 | * Optionally find copies from parents' files. | |
2450 | */ | |
2451 | if (opt & PICKAXE_BLAME_COPY) { | |
2452 | if (sb->copy_score > sb->move_score) | |
2453 | filter_small(sb, &toosmall, &origin->suspects, sb->copy_score); | |
2454 | else if (sb->copy_score < sb->move_score) { | |
2455 | origin->suspects = blame_merge(origin->suspects, toosmall); | |
2456 | toosmall = NULL; | |
2457 | filter_small(sb, &toosmall, &origin->suspects, sb->copy_score); | |
2458 | } | |
2459 | if (!origin->suspects) | |
2460 | goto finish; | |
2461 | ||
2462 | for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); | |
2463 | i < num_sg && sg; | |
2464 | sg = sg->next, i++) { | |
2465 | struct blame_origin *porigin = sg_origin[i]; | |
2466 | find_copy_in_parent(sb, &blametail, &toosmall, | |
2467 | origin, sg->item, porigin, opt); | |
2468 | if (!origin->suspects) | |
2469 | goto finish; | |
2470 | } | |
2471 | } | |
2472 | ||
2473 | finish: | |
2474 | *blametail = NULL; | |
2475 | distribute_blame(sb, blames); | |
2476 | /* | |
2477 | * prepend toosmall to origin->suspects | |
2478 | * | |
2479 | * There is no point in sorting: this ends up on a big | |
2480 | * unsorted list in the caller anyway. | |
2481 | */ | |
2482 | if (toosmall) { | |
2483 | struct blame_entry **tail = &toosmall; | |
2484 | while (*tail) | |
2485 | tail = &(*tail)->next; | |
2486 | *tail = origin->suspects; | |
2487 | origin->suspects = toosmall; | |
2488 | } | |
2489 | for (i = 0; i < num_sg; i++) { | |
2490 | if (sg_origin[i]) { | |
2491 | if (!sg_origin[i]->suspects) | |
2492 | drop_origin_blob(sg_origin[i]); | |
2493 | blame_origin_decref(sg_origin[i]); | |
2494 | } | |
2495 | } | |
2496 | drop_origin_blob(origin); | |
2497 | if (sg_buf != sg_origin) | |
2498 | free(sg_origin); | |
2499 | } | |
2500 | ||
2501 | /* | |
2502 | * The main loop -- while we have blobs with lines whose true origin | |
2503 | * is still unknown, pick one blob, and allow its lines to pass blames | |
2504 | * to its parents. */ | |
2505 | void assign_blame(struct blame_scoreboard *sb, int opt) | |
2506 | { | |
2507 | struct rev_info *revs = sb->revs; | |
2508 | struct commit *commit = prio_queue_get(&sb->commits); | |
2509 | ||
2510 | while (commit) { | |
2511 | struct blame_entry *ent; | |
2512 | struct blame_origin *suspect = get_blame_suspects(commit); | |
2513 | ||
2514 | /* find one suspect to break down */ | |
2515 | while (suspect && !suspect->suspects) | |
2516 | suspect = suspect->next; | |
2517 | ||
2518 | if (!suspect) { | |
2519 | commit = prio_queue_get(&sb->commits); | |
2520 | continue; | |
2521 | } | |
2522 | ||
2523 | assert(commit == suspect->commit); | |
2524 | ||
2525 | /* | |
2526 | * We will use this suspect later in the loop, | |
2527 | * so hold onto it in the meantime. | |
2528 | */ | |
2529 | blame_origin_incref(suspect); | |
2530 | parse_commit(commit); | |
2531 | if (sb->reverse || | |
2532 | (!(commit->object.flags & UNINTERESTING) && | |
2533 | !(revs->max_age != -1 && commit->date < revs->max_age))) | |
2534 | pass_blame(sb, suspect, opt); | |
2535 | else { | |
2536 | commit->object.flags |= UNINTERESTING; | |
2537 | if (commit->object.parsed) | |
2538 | mark_parents_uninteresting(commit); | |
2539 | } | |
2540 | /* treat root commit as boundary */ | |
2541 | if (!commit->parents && !sb->show_root) | |
2542 | commit->object.flags |= UNINTERESTING; | |
2543 | ||
2544 | /* Take responsibility for the remaining entries */ | |
2545 | ent = suspect->suspects; | |
2546 | if (ent) { | |
2547 | suspect->guilty = 1; | |
2548 | for (;;) { | |
2549 | struct blame_entry *next = ent->next; | |
2550 | if (sb->found_guilty_entry) | |
2551 | sb->found_guilty_entry(ent, sb->found_guilty_entry_data); | |
2552 | if (next) { | |
2553 | ent = next; | |
2554 | continue; | |
2555 | } | |
2556 | ent->next = sb->ent; | |
2557 | sb->ent = suspect->suspects; | |
2558 | suspect->suspects = NULL; | |
2559 | break; | |
2560 | } | |
2561 | } | |
2562 | blame_origin_decref(suspect); | |
2563 | ||
2564 | if (sb->debug) /* sanity */ | |
2565 | sanity_check_refcnt(sb); | |
2566 | } | |
2567 | } | |
2568 | ||
2569 | /* | |
2570 | * To allow quick access to the contents of nth line in the | |
2571 | * final image, prepare an index in the scoreboard. | |
2572 | */ | |
2573 | static int prepare_lines(struct blame_scoreboard *sb) | |
2574 | { | |
2575 | sb->num_lines = find_line_starts(&sb->lineno, sb->final_buf, | |
2576 | sb->final_buf_size); | |
2577 | return sb->num_lines; | |
2578 | } | |
2579 | ||
2580 | static struct commit *find_single_final(struct rev_info *revs, | |
2581 | const char **name_p) | |
2582 | { | |
2583 | int i; | |
2584 | struct commit *found = NULL; | |
2585 | const char *name = NULL; | |
2586 | ||
2587 | for (i = 0; i < revs->pending.nr; i++) { | |
2588 | struct object *obj = revs->pending.objects[i].item; | |
2589 | if (obj->flags & UNINTERESTING) | |
2590 | continue; | |
2591 | obj = deref_tag(revs->repo, obj, NULL, 0); | |
2592 | if (obj->type != OBJ_COMMIT) | |
2593 | die("Non commit %s?", revs->pending.objects[i].name); | |
2594 | if (found) | |
2595 | die("More than one commit to dig from %s and %s?", | |
2596 | revs->pending.objects[i].name, name); | |
2597 | found = (struct commit *)obj; | |
2598 | name = revs->pending.objects[i].name; | |
2599 | } | |
2600 | if (name_p) | |
2601 | *name_p = xstrdup_or_null(name); | |
2602 | return found; | |
2603 | } | |
2604 | ||
2605 | static struct commit *dwim_reverse_initial(struct rev_info *revs, | |
2606 | const char **name_p) | |
2607 | { | |
2608 | /* | |
2609 | * DWIM "git blame --reverse ONE -- PATH" as | |
2610 | * "git blame --reverse ONE..HEAD -- PATH" but only do so | |
2611 | * when it makes sense. | |
2612 | */ | |
2613 | struct object *obj; | |
2614 | struct commit *head_commit; | |
2615 | struct object_id head_oid; | |
2616 | ||
2617 | if (revs->pending.nr != 1) | |
2618 | return NULL; | |
2619 | ||
2620 | /* Is that sole rev a committish? */ | |
2621 | obj = revs->pending.objects[0].item; | |
2622 | obj = deref_tag(revs->repo, obj, NULL, 0); | |
2623 | if (obj->type != OBJ_COMMIT) | |
2624 | return NULL; | |
2625 | ||
2626 | /* Do we have HEAD? */ | |
2627 | if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL)) | |
2628 | return NULL; | |
2629 | head_commit = lookup_commit_reference_gently(revs->repo, | |
2630 | &head_oid, 1); | |
2631 | if (!head_commit) | |
2632 | return NULL; | |
2633 | ||
2634 | /* Turn "ONE" into "ONE..HEAD" then */ | |
2635 | obj->flags |= UNINTERESTING; | |
2636 | add_pending_object(revs, &head_commit->object, "HEAD"); | |
2637 | ||
2638 | if (name_p) | |
2639 | *name_p = revs->pending.objects[0].name; | |
2640 | return (struct commit *)obj; | |
2641 | } | |
2642 | ||
2643 | static struct commit *find_single_initial(struct rev_info *revs, | |
2644 | const char **name_p) | |
2645 | { | |
2646 | int i; | |
2647 | struct commit *found = NULL; | |
2648 | const char *name = NULL; | |
2649 | ||
2650 | /* | |
2651 | * There must be one and only one negative commit, and it must be | |
2652 | * the boundary. | |
2653 | */ | |
2654 | for (i = 0; i < revs->pending.nr; i++) { | |
2655 | struct object *obj = revs->pending.objects[i].item; | |
2656 | if (!(obj->flags & UNINTERESTING)) | |
2657 | continue; | |
2658 | obj = deref_tag(revs->repo, obj, NULL, 0); | |
2659 | if (obj->type != OBJ_COMMIT) | |
2660 | die("Non commit %s?", revs->pending.objects[i].name); | |
2661 | if (found) | |
2662 | die("More than one commit to dig up from, %s and %s?", | |
2663 | revs->pending.objects[i].name, name); | |
2664 | found = (struct commit *) obj; | |
2665 | name = revs->pending.objects[i].name; | |
2666 | } | |
2667 | ||
2668 | if (!name) | |
2669 | found = dwim_reverse_initial(revs, &name); | |
2670 | if (!name) | |
2671 | die("No commit to dig up from?"); | |
2672 | ||
2673 | if (name_p) | |
2674 | *name_p = xstrdup(name); | |
2675 | return found; | |
2676 | } | |
2677 | ||
2678 | void init_scoreboard(struct blame_scoreboard *sb) | |
2679 | { | |
2680 | memset(sb, 0, sizeof(struct blame_scoreboard)); | |
2681 | sb->move_score = BLAME_DEFAULT_MOVE_SCORE; | |
2682 | sb->copy_score = BLAME_DEFAULT_COPY_SCORE; | |
2683 | } | |
2684 | ||
2685 | void setup_scoreboard(struct blame_scoreboard *sb, | |
2686 | const char *path, | |
2687 | struct blame_origin **orig) | |
2688 | { | |
2689 | const char *final_commit_name = NULL; | |
2690 | struct blame_origin *o; | |
2691 | struct commit *final_commit = NULL; | |
2692 | enum object_type type; | |
2693 | ||
2694 | init_blame_suspects(&blame_suspects); | |
2695 | ||
2696 | if (sb->reverse && sb->contents_from) | |
2697 | die(_("--contents and --reverse do not blend well.")); | |
2698 | ||
2699 | if (!sb->repo) | |
2700 | BUG("repo is NULL"); | |
2701 | ||
2702 | if (!sb->reverse) { | |
2703 | sb->final = find_single_final(sb->revs, &final_commit_name); | |
2704 | sb->commits.compare = compare_commits_by_commit_date; | |
2705 | } else { | |
2706 | sb->final = find_single_initial(sb->revs, &final_commit_name); | |
2707 | sb->commits.compare = compare_commits_by_reverse_commit_date; | |
2708 | } | |
2709 | ||
2710 | if (sb->final && sb->contents_from) | |
2711 | die(_("cannot use --contents with final commit object name")); | |
2712 | ||
2713 | if (sb->reverse && sb->revs->first_parent_only) | |
2714 | sb->revs->children.name = NULL; | |
2715 | ||
2716 | if (!sb->final) { | |
2717 | /* | |
2718 | * "--not A B -- path" without anything positive; | |
2719 | * do not default to HEAD, but use the working tree | |
2720 | * or "--contents". | |
2721 | */ | |
2722 | setup_work_tree(); | |
2723 | sb->final = fake_working_tree_commit(sb->repo, | |
2724 | &sb->revs->diffopt, | |
2725 | path, sb->contents_from); | |
2726 | add_pending_object(sb->revs, &(sb->final->object), ":"); | |
2727 | } | |
2728 | ||
2729 | if (sb->reverse && sb->revs->first_parent_only) { | |
2730 | final_commit = find_single_final(sb->revs, NULL); | |
2731 | if (!final_commit) | |
2732 | die(_("--reverse and --first-parent together require specified latest commit")); | |
2733 | } | |
2734 | ||
2735 | /* | |
2736 | * If we have bottom, this will mark the ancestors of the | |
2737 | * bottom commits we would reach while traversing as | |
2738 | * uninteresting. | |
2739 | */ | |
2740 | if (prepare_revision_walk(sb->revs)) | |
2741 | die(_("revision walk setup failed")); | |
2742 | ||
2743 | if (sb->reverse && sb->revs->first_parent_only) { | |
2744 | struct commit *c = final_commit; | |
2745 | ||
2746 | sb->revs->children.name = "children"; | |
2747 | while (c->parents && | |
2748 | !oideq(&c->object.oid, &sb->final->object.oid)) { | |
2749 | struct commit_list *l = xcalloc(1, sizeof(*l)); | |
2750 | ||
2751 | l->item = c; | |
2752 | if (add_decoration(&sb->revs->children, | |
2753 | &c->parents->item->object, l)) | |
2754 | BUG("not unique item in first-parent chain"); | |
2755 | c = c->parents->item; | |
2756 | } | |
2757 | ||
2758 | if (!oideq(&c->object.oid, &sb->final->object.oid)) | |
2759 | die(_("--reverse --first-parent together require range along first-parent chain")); | |
2760 | } | |
2761 | ||
2762 | if (is_null_oid(&sb->final->object.oid)) { | |
2763 | o = get_blame_suspects(sb->final); | |
2764 | sb->final_buf = xmemdupz(o->file.ptr, o->file.size); | |
2765 | sb->final_buf_size = o->file.size; | |
2766 | } | |
2767 | else { | |
2768 | o = get_origin(sb->final, path); | |
2769 | if (fill_blob_sha1_and_mode(sb->repo, o)) | |
2770 | die(_("no such path %s in %s"), path, final_commit_name); | |
2771 | ||
2772 | if (sb->revs->diffopt.flags.allow_textconv && | |
2773 | textconv_object(sb->repo, path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf, | |
2774 | &sb->final_buf_size)) | |
2775 | ; | |
2776 | else | |
2777 | sb->final_buf = read_object_file(&o->blob_oid, &type, | |
2778 | &sb->final_buf_size); | |
2779 | ||
2780 | if (!sb->final_buf) | |
2781 | die(_("cannot read blob %s for path %s"), | |
2782 | oid_to_hex(&o->blob_oid), | |
2783 | path); | |
2784 | } | |
2785 | sb->num_read_blob++; | |
2786 | prepare_lines(sb); | |
2787 | ||
2788 | if (orig) | |
2789 | *orig = o; | |
2790 | ||
2791 | free((char *)final_commit_name); | |
2792 | } | |
2793 | ||
2794 | ||
2795 | ||
2796 | struct blame_entry *blame_entry_prepend(struct blame_entry *head, | |
2797 | long start, long end, | |
2798 | struct blame_origin *o) | |
2799 | { | |
2800 | struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry)); | |
2801 | new_head->lno = start; | |
2802 | new_head->num_lines = end - start; | |
2803 | new_head->suspect = o; | |
2804 | new_head->s_lno = start; | |
2805 | new_head->next = head; | |
2806 | blame_origin_incref(o); | |
2807 | return new_head; | |
2808 | } |