4d940cd37594e8483356ec6c52637c778d8c9895
1#include "cache.h"
2#include "string-list.h"
3#include "rerere.h"
4#include "xdiff-interface.h"
5#include "dir.h"
6#include "resolve-undo.h"
7#include "ll-merge.h"
8#include "attr.h"
9#define RESOLVED 0
11#define PUNTED 1
12#define THREE_STAGED 2
13void *RERERE_RESOLVED = &RERERE_RESOLVED;
14/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
16static int rerere_enabled = -1;
17/* automatically update cleanly resolved paths to the index */
19static int rerere_autoupdate;
20static char *merge_rr_path;
22const char *rerere_path(const char *hex, const char *file)
24{
25 return git_path("rr-cache/%s/%s", hex, file);
26}
27static int has_rerere_resolution(const char *hex)
29{
30 struct stat st;
31 return !stat(rerere_path(hex, "postimage"), &st);
32}
33static void read_rr(struct string_list *rr)
35{
36 unsigned char sha1[20];
37 char buf[PATH_MAX];
38 FILE *in = fopen(merge_rr_path, "r");
39 if (!in)
40 return;
41 while (fread(buf, 40, 1, in) == 1) {
42 int i;
43 char *name;
44 if (get_sha1_hex(buf, sha1))
45 die("corrupt MERGE_RR");
46 buf[40] = '\0';
47 name = xstrdup(buf);
48 if (fgetc(in) != '\t')
49 die("corrupt MERGE_RR");
50 for (i = 0; i < sizeof(buf); i++) {
51 int c = fgetc(in);
52 if (c < 0)
53 die("corrupt MERGE_RR");
54 buf[i] = c;
55 if (c == 0)
56 break;
57 }
58 if (i == sizeof(buf))
59 die("filename too long");
60 string_list_insert(rr, buf)->util = name;
61 }
62 fclose(in);
63}
64static struct lock_file write_lock;
66static int write_rr(struct string_list *rr, int out_fd)
68{
69 int i;
70 for (i = 0; i < rr->nr; i++) {
71 const char *path;
72 int length;
73 if (!rr->items[i].util)
74 continue;
75 path = rr->items[i].string;
76 length = strlen(path) + 1;
77 if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
78 write_str_in_full(out_fd, "\t") != 1 ||
79 write_in_full(out_fd, path, length) != length)
80 die("unable to write rerere record");
81 }
82 if (commit_lock_file(&write_lock) != 0)
83 die("unable to write rerere record");
84 return 0;
85}
86static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
88{
89 if (!count || *err)
90 return;
91 if (fwrite(p, count, 1, fp) != 1)
92 *err = errno;
93}
94static inline void ferr_puts(const char *s, FILE *fp, int *err)
96{
97 ferr_write(s, strlen(s), fp, err);
98}
99struct rerere_io {
101 int (*getline)(struct strbuf *, struct rerere_io *);
102 FILE *output;
103 int wrerror;
104 /* some more stuff */
105};
106static void rerere_io_putstr(const char *str, struct rerere_io *io)
108{
109 if (io->output)
110 ferr_puts(str, io->output, &io->wrerror);
111}
112static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
114{
115 char buf[64];
116 while (size) {
118 if (size < sizeof(buf) - 2) {
119 memset(buf, ch, size);
120 buf[size] = '\n';
121 buf[size + 1] = '\0';
122 size = 0;
123 } else {
124 int sz = sizeof(buf) - 1;
125 if (size <= sz)
126 sz -= (sz - size) + 1;
127 memset(buf, ch, sz);
128 buf[sz] = '\0';
129 size -= sz;
130 }
131 rerere_io_putstr(buf, io);
132 }
133}
134static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
136{
137 if (io->output)
138 ferr_write(mem, sz, io->output, &io->wrerror);
139}
140struct rerere_io_file {
142 struct rerere_io io;
143 FILE *input;
144};
145static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
147{
148 struct rerere_io_file *io = (struct rerere_io_file *)io_;
149 return strbuf_getwholeline(sb, io->input, '\n');
150}
151static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
153{
154 while (marker_size--)
155 if (*buf++ != marker_char)
156 return 0;
157 if (want_sp && *buf != ' ')
158 return 0;
159 return isspace(*buf);
160}
161static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
163{
164 git_SHA_CTX ctx;
165 int hunk_no = 0;
166 enum {
167 RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
168 } hunk = RR_CONTEXT;
169 struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
170 struct strbuf buf = STRBUF_INIT;
171 if (sha1)
173 git_SHA1_Init(&ctx);
174 while (!io->getline(&buf, io)) {
176 if (is_cmarker(buf.buf, '<', marker_size, 1)) {
177 if (hunk != RR_CONTEXT)
178 goto bad;
179 hunk = RR_SIDE_1;
180 } else if (is_cmarker(buf.buf, '|', marker_size, 0)) {
181 if (hunk != RR_SIDE_1)
182 goto bad;
183 hunk = RR_ORIGINAL;
184 } else if (is_cmarker(buf.buf, '=', marker_size, 0)) {
185 if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
186 goto bad;
187 hunk = RR_SIDE_2;
188 } else if (is_cmarker(buf.buf, '>', marker_size, 1)) {
189 if (hunk != RR_SIDE_2)
190 goto bad;
191 if (strbuf_cmp(&one, &two) > 0)
192 strbuf_swap(&one, &two);
193 hunk_no++;
194 hunk = RR_CONTEXT;
195 rerere_io_putconflict('<', marker_size, io);
196 rerere_io_putmem(one.buf, one.len, io);
197 rerere_io_putconflict('=', marker_size, io);
198 rerere_io_putmem(two.buf, two.len, io);
199 rerere_io_putconflict('>', marker_size, io);
200 if (sha1) {
201 git_SHA1_Update(&ctx, one.buf ? one.buf : "",
202 one.len + 1);
203 git_SHA1_Update(&ctx, two.buf ? two.buf : "",
204 two.len + 1);
205 }
206 strbuf_reset(&one);
207 strbuf_reset(&two);
208 } else if (hunk == RR_SIDE_1)
209 strbuf_addstr(&one, buf.buf);
210 else if (hunk == RR_ORIGINAL)
211 ; /* discard */
212 else if (hunk == RR_SIDE_2)
213 strbuf_addstr(&two, buf.buf);
214 else
215 rerere_io_putstr(buf.buf, io);
216 continue;
217 bad:
218 hunk = 99; /* force error exit */
219 break;
220 }
221 strbuf_release(&one);
222 strbuf_release(&two);
223 strbuf_release(&buf);
224 if (sha1)
226 git_SHA1_Final(sha1, &ctx);
227 if (hunk != RR_CONTEXT)
228 return -1;
229 return hunk_no;
230}
231static int handle_file(const char *path, unsigned char *sha1, const char *output)
233{
234 int hunk_no = 0;
235 struct rerere_io_file io;
236 int marker_size = ll_merge_marker_size(path);
237 memset(&io, 0, sizeof(io));
239 io.io.getline = rerere_file_getline;
240 io.input = fopen(path, "r");
241 io.io.wrerror = 0;
242 if (!io.input)
243 return error("Could not open %s", path);
244 if (output) {
246 io.io.output = fopen(output, "w");
247 if (!io.io.output) {
248 fclose(io.input);
249 return error("Could not write %s", output);
250 }
251 }
252 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
254 fclose(io.input);
256 if (io.io.wrerror)
257 error("There were errors while writing %s (%s)",
258 path, strerror(io.io.wrerror));
259 if (io.io.output && fclose(io.io.output))
260 io.io.wrerror = error("Failed to flush %s: %s",
261 path, strerror(errno));
262 if (hunk_no < 0) {
264 if (output)
265 unlink_or_warn(output);
266 return error("Could not parse conflict hunks in %s", path);
267 }
268 if (io.io.wrerror)
269 return -1;
270 return hunk_no;
271}
272struct rerere_io_mem {
274 struct rerere_io io;
275 struct strbuf input;
276};
277static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
279{
280 struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
281 char *ep;
282 size_t len;
283 strbuf_release(sb);
285 if (!io->input.len)
286 return -1;
287 ep = memchr(io->input.buf, '\n', io->input.len);
288 if (!ep)
289 ep = io->input.buf + io->input.len;
290 else if (*ep == '\n')
291 ep++;
292 len = ep - io->input.buf;
293 strbuf_add(sb, io->input.buf, len);
294 strbuf_remove(&io->input, 0, len);
295 return 0;
296}
297static int handle_cache(const char *path, unsigned char *sha1, const char *output)
299{
300 mmfile_t mmfile[3];
301 mmbuffer_t result = {NULL, 0};
302 struct cache_entry *ce;
303 int pos, len, i, hunk_no;
304 struct rerere_io_mem io;
305 int marker_size = ll_merge_marker_size(path);
306 /*
308 * Reproduce the conflicted merge in-core
309 */
310 len = strlen(path);
311 pos = cache_name_pos(path, len);
312 if (0 <= pos)
313 return -1;
314 pos = -pos - 1;
315 for (i = 0; i < 3; i++) {
317 enum object_type type;
318 unsigned long size;
319 mmfile[i].size = 0;
321 mmfile[i].ptr = NULL;
322 if (active_nr <= pos)
323 break;
324 ce = active_cache[pos++];
325 if (ce_namelen(ce) != len || memcmp(ce->name, path, len)
326 || ce_stage(ce) != i + 1)
327 break;
328 mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
329 mmfile[i].size = size;
330 }
331 for (i = 0; i < 3; i++) {
332 if (!mmfile[i].ptr && !mmfile[i].size)
333 mmfile[i].ptr = xstrdup("");
334 }
335 /*
336 * NEEDSWORK: handle conflicts from merges with
337 * merge.renormalize set, too
338 */
339 ll_merge(&result, path, &mmfile[0], NULL,
340 &mmfile[1], "ours",
341 &mmfile[2], "theirs", NULL);
342 for (i = 0; i < 3; i++)
343 free(mmfile[i].ptr);
344 memset(&io, 0, sizeof(io));
346 io.io.getline = rerere_mem_getline;
347 if (output)
348 io.io.output = fopen(output, "w");
349 else
350 io.io.output = NULL;
351 strbuf_init(&io.input, 0);
352 strbuf_attach(&io.input, result.ptr, result.size, result.size);
353 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
355 strbuf_release(&io.input);
356 if (io.io.output)
357 fclose(io.io.output);
358 return hunk_no;
359}
360static int check_one_conflict(int i, int *type)
362{
363 struct cache_entry *e = active_cache[i];
364 if (!ce_stage(e)) {
366 *type = RESOLVED;
367 return i + 1;
368 }
369 *type = PUNTED;
371 if (ce_stage(e) == 1) {
372 if (active_nr <= ++i)
373 return i + 1;
374 }
375 /* Only handle regular files with both stages #2 and #3 */
377 if (i + 1 < active_nr) {
378 struct cache_entry *e2 = active_cache[i];
379 struct cache_entry *e3 = active_cache[i + 1];
380 if (ce_stage(e2) == 2 &&
381 ce_stage(e3) == 3 &&
382 ce_same_name(e, e3) &&
383 S_ISREG(e2->ce_mode) &&
384 S_ISREG(e3->ce_mode))
385 *type = THREE_STAGED;
386 }
387 /* Skip the entries with the same name */
389 while (i < active_nr && ce_same_name(e, active_cache[i]))
390 i++;
391 return i;
392}
393static int find_conflict(struct string_list *conflict)
395{
396 int i;
397 if (read_cache() < 0)
398 return error("Could not read index");
399 for (i = 0; i < active_nr;) {
401 int conflict_type;
402 struct cache_entry *e = active_cache[i];
403 i = check_one_conflict(i, &conflict_type);
404 if (conflict_type == THREE_STAGED)
405 string_list_insert(conflict, (const char *)e->name);
406 }
407 return 0;
408}
409int rerere_remaining(struct string_list *merge_rr)
411{
412 int i;
413 if (read_cache() < 0)
414 return error("Could not read index");
415 for (i = 0; i < active_nr;) {
417 int conflict_type;
418 struct cache_entry *e = active_cache[i];
419 i = check_one_conflict(i, &conflict_type);
420 if (conflict_type == PUNTED)
421 string_list_insert(merge_rr, (const char *)e->name);
422 else if (conflict_type == RESOLVED) {
423 struct string_list_item *it;
424 it = string_list_lookup(merge_rr, (const char *)e->name);
425 if (it != NULL) {
426 free(it->util);
427 it->util = RERERE_RESOLVED;
428 }
429 }
430 }
431 return 0;
432}
433static int merge(const char *name, const char *path)
435{
436 int ret;
437 mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
438 mmbuffer_t result = {NULL, 0};
439 if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
441 return 1;
442 if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
444 read_mmfile(&base, rerere_path(name, "preimage")) ||
445 read_mmfile(&other, rerere_path(name, "postimage"))) {
446 ret = 1;
447 goto out;
448 }
449 ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
450 if (!ret) {
451 FILE *f;
452 if (utime(rerere_path(name, "postimage"), NULL) < 0)
454 warning("failed utime() on %s: %s",
455 rerere_path(name, "postimage"),
456 strerror(errno));
457 f = fopen(path, "w");
458 if (!f)
459 return error("Could not open %s: %s", path,
460 strerror(errno));
461 if (fwrite(result.ptr, result.size, 1, f) != 1)
462 error("Could not write %s: %s", path, strerror(errno));
463 if (fclose(f))
464 return error("Writing %s failed: %s", path,
465 strerror(errno));
466 }
467out:
469 free(cur.ptr);
470 free(base.ptr);
471 free(other.ptr);
472 free(result.ptr);
473 return ret;
475}
476static struct lock_file index_lock;
478static int update_paths(struct string_list *update)
480{
481 int i;
482 int fd = hold_locked_index(&index_lock, 0);
483 int status = 0;
484 if (fd < 0)
486 return -1;
487 for (i = 0; i < update->nr; i++) {
489 struct string_list_item *item = &update->items[i];
490 if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS))
491 status = -1;
492 }
493 if (!status && active_cache_changed) {
495 if (write_cache(fd, active_cache, active_nr) ||
496 commit_locked_index(&index_lock))
497 die("Unable to write new index file");
498 } else if (fd >= 0)
499 rollback_lock_file(&index_lock);
500 return status;
501}
502static int do_plain_rerere(struct string_list *rr, int fd)
504{
505 struct string_list conflict = STRING_LIST_INIT_DUP;
506 struct string_list update = STRING_LIST_INIT_DUP;
507 int i;
508 find_conflict(&conflict);
510 /*
512 * MERGE_RR records paths with conflicts immediately after merge
513 * failed. Some of the conflicted paths might have been hand resolved
514 * in the working tree since then, but the initial run would catch all
515 * and register their preimages.
516 */
517 for (i = 0; i < conflict.nr; i++) {
519 const char *path = conflict.items[i].string;
520 if (!string_list_has_string(rr, path)) {
521 unsigned char sha1[20];
522 char *hex;
523 int ret;
524 ret = handle_file(path, sha1, NULL);
525 if (ret < 1)
526 continue;
527 hex = xstrdup(sha1_to_hex(sha1));
528 string_list_insert(rr, path)->util = hex;
529 if (mkdir_in_gitdir(git_path("rr-cache/%s", hex)))
530 continue;
531 handle_file(path, NULL, rerere_path(hex, "preimage"));
532 fprintf(stderr, "Recorded preimage for '%s'\n", path);
533 }
534 }
535 /*
537 * Now some of the paths that had conflicts earlier might have been
538 * hand resolved. Others may be similar to a conflict already that
539 * was resolved before.
540 */
541 for (i = 0; i < rr->nr; i++) {
543 int ret;
544 const char *path = rr->items[i].string;
545 const char *name = (const char *)rr->items[i].util;
546 if (has_rerere_resolution(name)) {
548 if (!merge(name, path)) {
549 const char *msg;
550 if (rerere_autoupdate) {
551 string_list_insert(&update, path);
552 msg = "Staged '%s' using previous resolution.\n";
553 } else
554 msg = "Resolved '%s' using previous resolution.\n";
555 fprintf(stderr, msg, path);
556 goto mark_resolved;
557 }
558 }
559 /* Let's see if we have resolved it. */
561 ret = handle_file(path, NULL, NULL);
562 if (ret)
563 continue;
564 fprintf(stderr, "Recorded resolution for '%s'.\n", path);
566 copy_file(rerere_path(name, "postimage"), path, 0666);
567 mark_resolved:
568 rr->items[i].util = NULL;
569 }
570 if (update.nr)
572 update_paths(&update);
573 return write_rr(rr, fd);
575}
576static int git_rerere_config(const char *var, const char *value, void *cb)
578{
579 if (!strcmp(var, "rerere.enabled"))
580 rerere_enabled = git_config_bool(var, value);
581 else if (!strcmp(var, "rerere.autoupdate"))
582 rerere_autoupdate = git_config_bool(var, value);
583 else
584 return git_default_config(var, value, cb);
585 return 0;
586}
587static int is_rerere_enabled(void)
589{
590 const char *rr_cache;
591 int rr_cache_exists;
592 if (!rerere_enabled)
594 return 0;
595 rr_cache = git_path("rr-cache");
597 rr_cache_exists = is_directory(rr_cache);
598 if (rerere_enabled < 0)
599 return rr_cache_exists;
600 if (!rr_cache_exists && mkdir_in_gitdir(rr_cache))
602 die("Could not create directory %s", rr_cache);
603 return 1;
604}
605int setup_rerere(struct string_list *merge_rr, int flags)
607{
608 int fd;
609 git_config(git_rerere_config, NULL);
611 if (!is_rerere_enabled())
612 return -1;
613 if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
615 rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
616 merge_rr_path = git_pathdup("MERGE_RR");
617 fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
618 LOCK_DIE_ON_ERROR);
619 read_rr(merge_rr);
620 return fd;
621}
622int rerere(int flags)
624{
625 struct string_list merge_rr = STRING_LIST_INIT_DUP;
626 int fd;
627 fd = setup_rerere(&merge_rr, flags);
629 if (fd < 0)
630 return 0;
631 return do_plain_rerere(&merge_rr, fd);
632}
633static int rerere_forget_one_path(const char *path, struct string_list *rr)
635{
636 const char *filename;
637 char *hex;
638 unsigned char sha1[20];
639 int ret;
640 ret = handle_cache(path, sha1, NULL);
642 if (ret < 1)
643 return error("Could not parse conflict hunks in '%s'", path);
644 hex = xstrdup(sha1_to_hex(sha1));
645 filename = rerere_path(hex, "postimage");
646 if (unlink(filename))
647 return (errno == ENOENT
648 ? error("no remembered resolution for %s", path)
649 : error("cannot unlink %s: %s", filename, strerror(errno)));
650 handle_cache(path, sha1, rerere_path(hex, "preimage"));
652 fprintf(stderr, "Updated preimage for '%s'\n", path);
653 string_list_insert(rr, path)->util = hex;
656 fprintf(stderr, "Forgot resolution for %s\n", path);
657 return 0;
658}
659int rerere_forget(const char **pathspec)
661{
662 int i, fd;
663 struct string_list conflict = STRING_LIST_INIT_DUP;
664 struct string_list merge_rr = STRING_LIST_INIT_DUP;
665 if (read_cache() < 0)
667 return error("Could not read index");
668 fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
670 unmerge_cache(pathspec);
672 find_conflict(&conflict);
673 for (i = 0; i < conflict.nr; i++) {
674 struct string_list_item *it = &conflict.items[i];
675 if (!match_pathspec(pathspec, it->string, strlen(it->string),
676 0, NULL))
677 continue;
678 rerere_forget_one_path(it->string, &merge_rr);
679 }
680 return write_rr(&merge_rr, fd);
681}
682static time_t rerere_created_at(const char *name)
684{
685 struct stat st;
686 return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
687}
688static time_t rerere_last_used_at(const char *name)
690{
691 struct stat st;
692 return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
693}
694static void unlink_rr_item(const char *name)
696{
697 unlink(rerere_path(name, "thisimage"));
698 unlink(rerere_path(name, "preimage"));
699 unlink(rerere_path(name, "postimage"));
700 rmdir(git_path("rr-cache/%s", name));
701}
702struct rerere_gc_config_cb {
704 int cutoff_noresolve;
705 int cutoff_resolve;
706};
707static int git_rerere_gc_config(const char *var, const char *value, void *cb)
709{
710 struct rerere_gc_config_cb *cf = cb;
711 if (!strcmp(var, "gc.rerereresolved"))
713 cf->cutoff_resolve = git_config_int(var, value);
714 else if (!strcmp(var, "gc.rerereunresolved"))
715 cf->cutoff_noresolve = git_config_int(var, value);
716 else
717 return git_default_config(var, value, cb);
718 return 0;
719}
720void rerere_gc(struct string_list *rr)
722{
723 struct string_list to_remove = STRING_LIST_INIT_DUP;
724 DIR *dir;
725 struct dirent *e;
726 int i, cutoff;
727 time_t now = time(NULL), then;
728 struct rerere_gc_config_cb cf = { 15, 60 };
729 git_config(git_rerere_gc_config, &cf);
731 dir = opendir(git_path("rr-cache"));
732 if (!dir)
733 die_errno("unable to open rr-cache directory");
734 while ((e = readdir(dir))) {
735 if (is_dot_or_dotdot(e->d_name))
736 continue;
737 then = rerere_last_used_at(e->d_name);
739 if (then) {
740 cutoff = cf.cutoff_resolve;
741 } else {
742 then = rerere_created_at(e->d_name);
743 if (!then)
744 continue;
745 cutoff = cf.cutoff_noresolve;
746 }
747 if (then < now - cutoff * 86400)
748 string_list_append(&to_remove, e->d_name);
749 }
750 closedir(dir);
751 for (i = 0; i < to_remove.nr; i++)
752 unlink_rr_item(to_remove.items[i].string);
753 string_list_clear(&to_remove, 0);
754}
755void rerere_clear(struct string_list *merge_rr)
757{
758 int i;
759 for (i = 0; i < merge_rr->nr; i++) {
761 const char *name = (const char *)merge_rr->items[i].util;
762 if (!has_rerere_resolution(name))
763 unlink_rr_item(name);
764 }
765 unlink_or_warn(git_path("MERGE_RR"));
766}