Blob


1 /*
2 * Copyright (c) 2018, 2019, 2020 Stefan Sperling <stsp@openbsd.org>
3 * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
18 #include <sys/mman.h>
19 #include <sys/stat.h>
21 #include <errno.h>
22 #include <string.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <time.h>
26 #include <limits.h>
27 #include <zlib.h>
29 #include "got_compat.h"
31 #include "got_error.h"
32 #include "got_object.h"
33 #include "got_cancel.h"
34 #include "got_blame.h"
35 #include "got_commit_graph.h"
36 #include "got_opentemp.h"
38 #include "got_lib_inflate.h"
39 #include "got_lib_delta.h"
40 #include "got_lib_object.h"
41 #include "got_lib_diff.h"
43 #ifndef MAX
44 #define MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
45 #endif
47 struct got_blame_line {
48 int annotated;
49 struct got_object_id id;
50 };
52 struct got_blame {
53 struct diff_config *cfg;
54 int nlines; /* number of lines in file being blamed */
55 int nannotated; /* number of lines already annotated */
56 struct got_blame_line *lines; /* one per line */
57 int ncommits;
59 /*
60 * These change with every traversed commit. After diffing
61 * commits N:N-1, in preparation for diffing commits N-1:N-2,
62 * data for commit N is retained and flipped into data for N-1.
63 *
64 */
65 FILE *f1; /* older version from commit N-1. */
66 FILE *f2; /* newer version from commit N. */
67 unsigned char *map1;
68 unsigned char *map2;
69 off_t size1;
70 off_t size2;
71 int nlines1;
72 int nlines2;
73 off_t *line_offsets1;
74 off_t *line_offsets2;
76 /*
77 * Map line numbers of an older version of the file to valid line
78 * numbers in the version of the file being blamed. This map is
79 * updated with each commit we traverse throughout the file's history.
80 * Lines mapped to -1 do not correspond to any line in the version
81 * being blamed.
82 */
83 int *linemap1;
84 int *linemap2;
86 struct diff_data *data1;
87 struct diff_data *data2;
88 };
90 static const struct got_error *
91 annotate_line(struct got_blame *blame, int lineno,
92 struct got_commit_object *commit, struct got_object_id *id,
93 got_blame_cb cb, void *arg)
94 {
95 const struct got_error *err = NULL;
96 struct got_blame_line *line;
98 if (lineno < 0 || lineno >= blame->nlines)
99 return NULL;
101 line = &blame->lines[lineno];
102 if (line->annotated)
103 return NULL;
105 memcpy(&line->id, id, sizeof(line->id));
106 line->annotated = 1;
107 blame->nannotated++;
108 if (cb)
109 err = cb(arg, blame->nlines, lineno + 1, commit, id);
110 return err;
113 static const struct got_error *
114 blame_changes(struct got_blame *blame, struct diff_result *diff_result,
115 struct got_commit_object *commit, struct got_object_id *commit_id,
116 got_blame_cb cb, void *arg)
118 const struct got_error *err = NULL;
119 int i;
120 int idx1 = 0, idx2 = 0;
122 for (i = 0; i < diff_result->chunks.len &&
123 blame->nannotated < blame->nlines; i++) {
124 struct diff_chunk *c = diff_chunk_get(diff_result, i);
125 unsigned int left_count, right_count;
126 int j;
128 /*
129 * We do not need to worry about idx1/idx2 growing out
130 * of bounds because the diff implementation ensures
131 * that chunk ranges never exceed the number of lines
132 * in the left/right input files.
133 */
134 left_count = diff_chunk_get_left_count(c);
135 right_count = diff_chunk_get_right_count(c);
137 if (left_count == right_count) {
138 for (j = 0; j < left_count; j++) {
139 blame->linemap1[idx1++] =
140 blame->linemap2[idx2++];
142 continue;
145 if (right_count == 0) {
146 for (j = 0; j < left_count; j++) {
147 blame->linemap1[idx1++] = -1;
149 continue;
152 for (j = 0; j < right_count; j++) {
153 int ln = blame->linemap2[idx2++];
154 err = annotate_line(blame, ln, commit, commit_id,
155 cb, arg);
156 if (err)
157 return err;
158 if (blame->nlines == blame->nannotated)
159 break;
163 return NULL;
166 static const struct got_error *
167 blame_prepare_file(FILE *f, unsigned char **p, off_t *size,
168 int *nlines, off_t **line_offsets, struct diff_data *diff_data,
169 const struct diff_config *cfg, struct got_blob_object *blob)
171 const struct got_error *err = NULL;
172 int diff_flags = 0, rc;
174 err = got_object_blob_dump_to_file(size, nlines, line_offsets,
175 f, blob);
176 if (err)
177 return err;
179 #ifndef GOT_DIFF_NO_MMAP
180 *p = mmap(NULL, *size, PROT_READ, MAP_PRIVATE, fileno(f), 0);
181 if (*p == MAP_FAILED)
182 #endif
183 *p = NULL; /* fall back on file I/O */
185 /* Allow blaming lines in binary files even though it's useless. */
186 diff_flags |= DIFF_FLAG_FORCE_TEXT_DATA;
188 rc = diff_atomize_file(diff_data, cfg, f, *p, *size, diff_flags);
189 if (rc)
190 return got_error_set_errno(rc, "diff_atomize_file");
192 return NULL;
195 static const struct got_error *
196 blame_commit(struct got_blame *blame, struct got_object_id *id,
197 const char *path, struct got_repository *repo,
198 got_blame_cb cb, void *arg)
200 const struct got_error *err = NULL;
201 struct got_commit_object *commit = NULL, *pcommit = NULL;
202 struct got_object_qid *pid = NULL;
203 struct got_object_id *pblob_id = NULL;
204 struct got_blob_object *pblob = NULL;
205 struct diff_result *diff_result = NULL;
207 err = got_object_open_as_commit(&commit, repo, id);
208 if (err)
209 return err;
211 pid = STAILQ_FIRST(got_object_commit_get_parent_ids(commit));
212 if (pid == NULL) {
213 got_object_commit_close(commit);
214 return NULL;
217 err = got_object_open_as_commit(&pcommit, repo, &pid->id);
218 if (err)
219 goto done;
221 err = got_object_id_by_path(&pblob_id, repo, pcommit, path);
222 if (err) {
223 if (err->code == GOT_ERR_NO_TREE_ENTRY)
224 err = NULL;
225 goto done;
228 err = got_object_open_as_blob(&pblob, repo, pblob_id, 8192);
229 if (err)
230 goto done;
232 blame->f1 = got_opentemp();
233 if (blame->f1 == NULL) {
234 err = got_error_from_errno("got_opentemp");
235 goto done;
238 err = blame_prepare_file(blame->f1, &blame->map1, &blame->size1,
239 &blame->nlines1, &blame->line_offsets1, blame->data1,
240 blame->cfg, pblob);
241 if (err)
242 goto done;
244 diff_result = diff_main(blame->cfg, blame->data1, blame->data2);
245 if (diff_result == NULL) {
246 err = got_error_set_errno(ENOMEM, "malloc");
247 goto done;
249 if (diff_result->rc != DIFF_RC_OK) {
250 err = got_error_set_errno(diff_result->rc, "diff");
251 goto done;
253 if (diff_result->chunks.len > 0) {
254 if (blame->nlines1 > 0) {
255 blame->linemap1 = calloc(blame->nlines1,
256 sizeof(*blame->linemap1));
257 if (blame->linemap1 == NULL) {
258 err = got_error_from_errno("malloc");
259 goto done;
262 err = blame_changes(blame, diff_result, commit, id, cb, arg);
263 if (err)
264 goto done;
265 } else if (cb)
266 err = cb(arg, blame->nlines, -1, commit, id);
267 done:
268 if (diff_result)
269 diff_result_free(diff_result);
270 if (commit)
271 got_object_commit_close(commit);
272 if (pcommit)
273 got_object_commit_close(pcommit);
274 free(pblob_id);
275 if (pblob)
276 got_object_blob_close(pblob);
277 return err;
280 static const struct got_error *
281 blame_close(struct got_blame *blame)
283 const struct got_error *err = NULL;
285 diff_data_free(blame->data1);
286 free(blame->data1);
287 diff_data_free(blame->data2);
288 free(blame->data2);
289 if (blame->map1) {
290 if (munmap(blame->map1, blame->size1) == -1 && err == NULL)
291 err = got_error_from_errno("munmap");
293 if (blame->map2) {
294 if (munmap(blame->map2, blame->size2) == -1 && err == NULL)
295 err = got_error_from_errno("munmap");
297 if (blame->f1 && fclose(blame->f1) == EOF && err == NULL)
298 err = got_error_from_errno("fclose");
299 if (blame->f2 && fclose(blame->f2) == EOF && err == NULL)
300 err = got_error_from_errno("fclose");
301 free(blame->lines);
302 free(blame->line_offsets1);
303 free(blame->line_offsets2);
304 free(blame->linemap1);
305 free(blame->linemap2);
306 free(blame->cfg);
307 free(blame);
308 return err;
311 static int
312 atomize_file(struct diff_data *d, FILE *f, off_t filesize, int nlines,
313 off_t *line_offsets)
315 int i, rc = DIFF_RC_OK;
316 int embedded_nul = 0;
318 ARRAYLIST_INIT(d->atoms, nlines);
320 for (i = 0; i < nlines; i++) {
321 struct diff_atom *atom;
322 off_t len, pos = line_offsets[i];
323 unsigned int hash = 0;
324 int j;
326 ARRAYLIST_ADD(atom, d->atoms);
327 if (atom == NULL) {
328 rc = errno;
329 break;
332 if (i < nlines - 1)
333 len = line_offsets[i + 1] - pos;
334 else
335 len = filesize - pos;
337 if (fseeko(f, pos, SEEK_SET) == -1) {
338 rc = errno;
339 break;
341 for (j = 0; j < len; j++) {
342 int c = fgetc(f);
343 if (c == EOF) {
344 if (feof(f))
345 rc = EIO; /* unexpected EOF */
346 else
347 rc = errno;
348 goto done;
351 hash = diff_atom_hash_update(hash, (unsigned char)c);
353 if (c == '\0')
354 embedded_nul = 1;
357 *atom = (struct diff_atom){
358 .root = d,
359 .pos = pos,
360 .at = NULL, /* atom data is not memory-mapped */
361 .len = len,
362 .hash = hash,
363 };
366 /* File are considered binary if they contain embedded '\0' bytes. */
367 if (embedded_nul)
368 d->atomizer_flags |= DIFF_ATOMIZER_FOUND_BINARY_DATA;
369 done:
370 if (rc)
371 ARRAYLIST_FREE(d->atoms);
373 return rc;
376 static int
377 atomize_file_mmap(struct diff_data *d, unsigned char *p,
378 off_t filesize, int nlines, off_t *line_offsets)
380 int i, rc = DIFF_RC_OK;
381 int embedded_nul = 0;
383 ARRAYLIST_INIT(d->atoms, nlines);
385 for (i = 0; i < nlines; i++) {
386 struct diff_atom *atom;
387 off_t len, pos = line_offsets[i];
388 unsigned int hash = 0;
389 int j;
391 ARRAYLIST_ADD(atom, d->atoms);
392 if (atom == NULL) {
393 rc = errno;
394 break;
397 if (i < nlines - 1)
398 len = line_offsets[i + 1] - pos;
399 else
400 len = filesize - pos;
402 for (j = 0; j < len; j++)
403 hash = diff_atom_hash_update(hash, p[pos + j]);
405 if (!embedded_nul && memchr(&p[pos], '\0', len) != NULL)
406 embedded_nul = 1;
408 *atom = (struct diff_atom){
409 .root = d,
410 .pos = pos,
411 .at = &p[pos],
412 .len = len,
413 .hash = hash,
414 };
417 /* File are considered binary if they contain embedded '\0' bytes. */
418 if (embedded_nul)
419 d->atomizer_flags |= DIFF_ATOMIZER_FOUND_BINARY_DATA;
421 if (rc)
422 ARRAYLIST_FREE(d->atoms);
424 return rc;
427 /* Implements diff_atomize_func_t */
428 static int
429 blame_atomize_file(void *arg, struct diff_data *d)
431 struct got_blame *blame = arg;
433 if (d->f == blame->f1) {
434 if (blame->map1)
435 return atomize_file_mmap(d, blame->map1,
436 blame->size1, blame->nlines1,
437 blame->line_offsets1);
438 else
439 return atomize_file(d, blame->f1, blame->size1,
440 blame->nlines1, blame->line_offsets1);
441 } else if (d->f == blame->f2) {
442 if (d->atoms.len > 0) {
443 /* Re-use data from previous commit. */
444 return DIFF_RC_OK;
446 if (blame->map2)
447 return atomize_file_mmap(d, blame->map2,
448 blame->size2, blame->nlines2,
449 blame->line_offsets2);
450 else
451 return atomize_file(d, blame->f2, blame->size2,
452 blame->nlines2, blame->line_offsets2);
455 return DIFF_RC_OK;
458 static const struct got_error *
459 close_file2_and_reuse_file1(struct got_blame *blame)
461 struct diff_data *d;
463 free(blame->line_offsets2);
464 blame->line_offsets2 = blame->line_offsets1;
465 blame->line_offsets1 = NULL;
467 free(blame->linemap2);
468 blame->linemap2 = blame->linemap1;
469 blame->linemap1 = NULL;
471 if (blame->map2) {
472 if (munmap(blame->map2, blame->size2) == -1)
473 return got_error_from_errno("munmap");
474 blame->map2 = blame->map1;
475 blame->map1 = NULL;
478 blame->size2 = blame->size1;
479 blame->size1 = 0;
481 if (fclose(blame->f2) == EOF)
482 return got_error_from_errno("fclose");
483 blame->f2 = blame->f1;
484 blame->f1 = NULL;
486 blame->nlines2 = blame->nlines1;
487 blame->nlines1 = 0;
489 diff_data_free(blame->data2); /* does not free pointer itself */
490 memset(blame->data2, 0, sizeof(*blame->data2));
491 d = blame->data2;
492 blame->data2 = blame->data1;
493 blame->data1 = d;
495 return NULL;
498 static const struct got_error *
499 blame_open(struct got_blame **blamep, const char *path,
500 struct got_object_id *start_commit_id, struct got_repository *repo,
501 got_blame_cb cb, void *arg, got_cancel_cb cancel_cb, void *cancel_arg)
503 const struct got_error *err = NULL;
504 struct got_commit_object *start_commit = NULL, *last_commit = NULL;
505 struct got_object_id *obj_id = NULL;
506 struct got_blob_object *blob = NULL;
507 struct got_blame *blame = NULL;
508 struct got_object_id *id = NULL;
509 int lineno;
510 struct got_commit_graph *graph = NULL;
512 *blamep = NULL;
514 err = got_object_open_as_commit(&start_commit, repo, start_commit_id);
515 if (err)
516 goto done;
518 err = got_object_id_by_path(&obj_id, repo, start_commit, path);
519 if (err)
520 goto done;
522 err = got_object_open_as_blob(&blob, repo, obj_id, 8192);
523 if (err)
524 goto done;
526 blame = calloc(1, sizeof(*blame));
527 if (blame == NULL) {
528 err = got_error_from_errno("calloc");
529 goto done;
532 blame->data1 = calloc(1, sizeof(*blame->data1));
533 if (blame->data1 == NULL) {
534 err = got_error_from_errno("calloc");
535 goto done;
537 blame->data2 = calloc(1, sizeof(*blame->data2));
538 if (blame->data2 == NULL) {
539 err = got_error_from_errno("calloc");
540 goto done;
543 blame->f2 = got_opentemp();
544 if (blame->f2 == NULL) {
545 err = got_error_from_errno("got_opentemp");
546 goto done;
548 err = got_diff_get_config(&blame->cfg, GOT_DIFF_ALGORITHM_PATIENCE,
549 blame_atomize_file, blame);
550 if (err)
551 goto done;
553 err = blame_prepare_file(blame->f2, &blame->map2, &blame->size2,
554 &blame->nlines2, &blame->line_offsets2, blame->data2,
555 blame->cfg, blob);
556 blame->nlines = blame->nlines2;
557 if (err || blame->nlines == 0)
558 goto done;
560 got_object_blob_close(blob);
561 blob = NULL;
563 /* Don't include \n at EOF in the blame line count. */
564 if (blame->line_offsets2[blame->nlines - 1] == blame->size2)
565 blame->nlines--;
567 blame->lines = calloc(blame->nlines, sizeof(*blame->lines));
568 if (blame->lines == NULL) {
569 err = got_error_from_errno("calloc");
570 goto done;
573 blame->linemap2 = calloc(blame->nlines2, sizeof(*blame->linemap2));
574 if (blame->linemap2 == NULL) {
575 err = got_error_from_errno("calloc");
576 goto done;
578 for (lineno = 0; lineno < blame->nlines2; lineno++)
579 blame->linemap2[lineno] = lineno;
581 err = got_commit_graph_open(&graph, path, 1);
582 if (err)
583 goto done;
585 err = got_commit_graph_iter_start(graph, start_commit_id, repo,
586 cancel_cb, cancel_arg);
587 if (err)
588 goto done;
589 for (;;) {
590 struct got_object_id *next_id;
591 err = got_commit_graph_iter_next(&next_id, graph, repo,
592 cancel_cb, cancel_arg);
593 if (err) {
594 if (err->code == GOT_ERR_ITER_COMPLETED) {
595 err = NULL;
596 break;
598 goto done;
600 if (next_id) {
601 id = next_id;
602 err = blame_commit(blame, id, path, repo, cb, arg);
603 if (err) {
604 if (err->code == GOT_ERR_ITER_COMPLETED)
605 err = NULL;
606 goto done;
608 if (blame->nannotated == blame->nlines)
609 break;
611 err = close_file2_and_reuse_file1(blame);
612 if (err)
613 goto done;
617 if (id && blame->nannotated < blame->nlines) {
618 /* Annotate remaining non-annotated lines with last commit. */
619 err = got_object_open_as_commit(&last_commit, repo, id);
620 if (err)
621 goto done;
622 for (lineno = 0; lineno < blame->nlines; lineno++) {
623 err = annotate_line(blame, lineno, last_commit, id,
624 cb, arg);
625 if (err)
626 goto done;
630 done:
631 if (graph)
632 got_commit_graph_close(graph);
633 free(obj_id);
634 if (blob)
635 got_object_blob_close(blob);
636 if (start_commit)
637 got_object_commit_close(start_commit);
638 if (last_commit)
639 got_object_commit_close(last_commit);
640 if (err) {
641 if (blame)
642 blame_close(blame);
643 } else
644 *blamep = blame;
646 return err;
649 const struct got_error *
650 got_blame(const char *path, struct got_object_id *commit_id,
651 struct got_repository *repo, got_blame_cb cb, void *arg,
652 got_cancel_cb cancel_cb, void* cancel_arg)
654 const struct got_error *err = NULL, *close_err = NULL;
655 struct got_blame *blame;
656 char *abspath;
658 if (asprintf(&abspath, "%s%s", path[0] == '/' ? "" : "/", path) == -1)
659 return got_error_from_errno2("asprintf", path);
661 err = blame_open(&blame, abspath, commit_id, repo, cb, arg,
662 cancel_cb, cancel_arg);
663 free(abspath);
664 if (blame)
665 close_err = blame_close(blame);
666 return err ? err : close_err;