git-multimail: update to release 1.2.0
[git.git] / rerere.c
blob403c700c326e4551aea183523af6ed46e1476432
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "string-list.h"
4 #include "rerere.h"
5 #include "xdiff-interface.h"
6 #include "dir.h"
7 #include "resolve-undo.h"
8 #include "ll-merge.h"
9 #include "attr.h"
10 #include "pathspec.h"
12 #define RESOLVED 0
13 #define PUNTED 1
14 #define THREE_STAGED 2
15 void *RERERE_RESOLVED = &RERERE_RESOLVED;
17 /* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
18 static int rerere_enabled = -1;
20 /* automatically update cleanly resolved paths to the index */
21 static int rerere_autoupdate;
23 static void free_rerere_id(struct string_list_item *item)
25 free(item->util);
28 static const char *rerere_id_hex(const struct rerere_id *id)
30 return id->hex;
33 const char *rerere_path(const struct rerere_id *id, const char *file)
35 if (!file)
36 return git_path("rr-cache/%s", rerere_id_hex(id));
38 return git_path("rr-cache/%s/%s", rerere_id_hex(id), file);
41 static int has_rerere_resolution(const struct rerere_id *id)
43 struct stat st;
45 return !stat(rerere_path(id, "postimage"), &st);
48 static struct rerere_id *new_rerere_id_hex(char *hex)
50 struct rerere_id *id = xmalloc(sizeof(*id));
51 strcpy(id->hex, hex);
52 return id;
55 static struct rerere_id *new_rerere_id(unsigned char *sha1)
57 return new_rerere_id_hex(sha1_to_hex(sha1));
61 * $GIT_DIR/MERGE_RR file is a collection of records, each of which is
62 * "conflict ID", a HT and pathname, terminated with a NUL, and is
63 * used to keep track of the set of paths that "rerere" may need to
64 * work on (i.e. what is left by the previous invocation of "git
65 * rerere" during the current conflict resolution session).
67 static void read_rr(struct string_list *rr)
69 struct strbuf buf = STRBUF_INIT;
70 FILE *in = fopen(git_path_merge_rr(), "r");
72 if (!in)
73 return;
74 while (!strbuf_getwholeline(&buf, in, '\0')) {
75 char *path;
76 unsigned char sha1[20];
77 struct rerere_id *id;
79 /* There has to be the hash, tab, path and then NUL */
80 if (buf.len < 42 || get_sha1_hex(buf.buf, sha1))
81 die("corrupt MERGE_RR");
83 if (buf.buf[40] != '\t')
84 die("corrupt MERGE_RR");
85 buf.buf[40] = '\0';
86 path = buf.buf + 41;
87 id = new_rerere_id_hex(buf.buf);
88 string_list_insert(rr, path)->util = id;
90 strbuf_release(&buf);
91 fclose(in);
94 static struct lock_file write_lock;
96 static int write_rr(struct string_list *rr, int out_fd)
98 int i;
99 for (i = 0; i < rr->nr; i++) {
100 struct strbuf buf = STRBUF_INIT;
101 struct rerere_id *id;
103 assert(rr->items[i].util != RERERE_RESOLVED);
105 id = rr->items[i].util;
106 if (!id)
107 continue;
108 strbuf_addf(&buf, "%s\t%s%c",
109 rerere_id_hex(id),
110 rr->items[i].string, 0);
111 if (write_in_full(out_fd, buf.buf, buf.len) != buf.len)
112 die("unable to write rerere record");
114 strbuf_release(&buf);
116 if (commit_lock_file(&write_lock) != 0)
117 die("unable to write rerere record");
118 return 0;
122 * "rerere" interacts with conflicted file contents using this I/O
123 * abstraction. It reads a conflicted contents from one place via
124 * "getline()" method, and optionally can write it out after
125 * normalizing the conflicted hunks to the "output". Subclasses of
126 * rerere_io embed this structure at the beginning of their own
127 * rerere_io object.
129 struct rerere_io {
130 int (*getline)(struct strbuf *, struct rerere_io *);
131 FILE *output;
132 int wrerror;
133 /* some more stuff */
136 static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
138 if (!count || *err)
139 return;
140 if (fwrite(p, count, 1, fp) != 1)
141 *err = errno;
144 static inline void ferr_puts(const char *s, FILE *fp, int *err)
146 ferr_write(s, strlen(s), fp, err);
149 static void rerere_io_putstr(const char *str, struct rerere_io *io)
151 if (io->output)
152 ferr_puts(str, io->output, &io->wrerror);
156 * Write a conflict marker to io->output (if defined).
158 static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
160 char buf[64];
162 while (size) {
163 if (size <= sizeof(buf) - 2) {
164 memset(buf, ch, size);
165 buf[size] = '\n';
166 buf[size + 1] = '\0';
167 size = 0;
168 } else {
169 int sz = sizeof(buf) - 1;
172 * Make sure we will not write everything out
173 * in this round by leaving at least 1 byte
174 * for the next round, giving the next round
175 * a chance to add the terminating LF. Yuck.
177 if (size <= sz)
178 sz -= (sz - size) + 1;
179 memset(buf, ch, sz);
180 buf[sz] = '\0';
181 size -= sz;
183 rerere_io_putstr(buf, io);
187 static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
189 if (io->output)
190 ferr_write(mem, sz, io->output, &io->wrerror);
194 * Subclass of rerere_io that reads from an on-disk file
196 struct rerere_io_file {
197 struct rerere_io io;
198 FILE *input;
202 * ... and its getline() method implementation
204 static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
206 struct rerere_io_file *io = (struct rerere_io_file *)io_;
207 return strbuf_getwholeline(sb, io->input, '\n');
211 * Require the exact number of conflict marker letters, no more, no
212 * less, followed by SP or any whitespace
213 * (including LF).
215 static int is_cmarker(char *buf, int marker_char, int marker_size)
217 int want_sp;
220 * The beginning of our version and the end of their version
221 * always are labeled like "<<<<< ours" or ">>>>> theirs",
222 * hence we set want_sp for them. Note that the version from
223 * the common ancestor in diff3-style output is not always
224 * labelled (e.g. "||||| common" is often seen but "|||||"
225 * alone is also valid), so we do not set want_sp.
227 want_sp = (marker_char == '<') || (marker_char == '>');
229 while (marker_size--)
230 if (*buf++ != marker_char)
231 return 0;
232 if (want_sp && *buf != ' ')
233 return 0;
234 return isspace(*buf);
238 * Read contents a file with conflicts, normalize the conflicts
239 * by (1) discarding the common ancestor version in diff3-style,
240 * (2) reordering our side and their side so that whichever sorts
241 * alphabetically earlier comes before the other one, while
242 * computing the "conflict ID", which is just an SHA-1 hash of
243 * one side of the conflict, NUL, the other side of the conflict,
244 * and NUL concatenated together.
246 * Return the number of conflict hunks found.
248 * NEEDSWORK: the logic and theory of operation behind this conflict
249 * normalization may deserve to be documented somewhere, perhaps in
250 * Documentation/technical/rerere.txt.
252 static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
254 git_SHA_CTX ctx;
255 int hunk_no = 0;
256 enum {
257 RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
258 } hunk = RR_CONTEXT;
259 struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
260 struct strbuf buf = STRBUF_INIT;
262 if (sha1)
263 git_SHA1_Init(&ctx);
265 while (!io->getline(&buf, io)) {
266 if (is_cmarker(buf.buf, '<', marker_size)) {
267 if (hunk != RR_CONTEXT)
268 goto bad;
269 hunk = RR_SIDE_1;
270 } else if (is_cmarker(buf.buf, '|', marker_size)) {
271 if (hunk != RR_SIDE_1)
272 goto bad;
273 hunk = RR_ORIGINAL;
274 } else if (is_cmarker(buf.buf, '=', marker_size)) {
275 if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
276 goto bad;
277 hunk = RR_SIDE_2;
278 } else if (is_cmarker(buf.buf, '>', marker_size)) {
279 if (hunk != RR_SIDE_2)
280 goto bad;
281 if (strbuf_cmp(&one, &two) > 0)
282 strbuf_swap(&one, &two);
283 hunk_no++;
284 hunk = RR_CONTEXT;
285 rerere_io_putconflict('<', marker_size, io);
286 rerere_io_putmem(one.buf, one.len, io);
287 rerere_io_putconflict('=', marker_size, io);
288 rerere_io_putmem(two.buf, two.len, io);
289 rerere_io_putconflict('>', marker_size, io);
290 if (sha1) {
291 git_SHA1_Update(&ctx, one.buf ? one.buf : "",
292 one.len + 1);
293 git_SHA1_Update(&ctx, two.buf ? two.buf : "",
294 two.len + 1);
296 strbuf_reset(&one);
297 strbuf_reset(&two);
298 } else if (hunk == RR_SIDE_1)
299 strbuf_addbuf(&one, &buf);
300 else if (hunk == RR_ORIGINAL)
301 ; /* discard */
302 else if (hunk == RR_SIDE_2)
303 strbuf_addbuf(&two, &buf);
304 else
305 rerere_io_putstr(buf.buf, io);
306 continue;
307 bad:
308 hunk = 99; /* force error exit */
309 break;
311 strbuf_release(&one);
312 strbuf_release(&two);
313 strbuf_release(&buf);
315 if (sha1)
316 git_SHA1_Final(sha1, &ctx);
317 if (hunk != RR_CONTEXT)
318 return -1;
319 return hunk_no;
323 * Scan the path for conflicts, do the "handle_path()" thing above, and
324 * return the number of conflict hunks found.
326 static int handle_file(const char *path, unsigned char *sha1, const char *output)
328 int hunk_no = 0;
329 struct rerere_io_file io;
330 int marker_size = ll_merge_marker_size(path);
332 memset(&io, 0, sizeof(io));
333 io.io.getline = rerere_file_getline;
334 io.input = fopen(path, "r");
335 io.io.wrerror = 0;
336 if (!io.input)
337 return error("Could not open %s", path);
339 if (output) {
340 io.io.output = fopen(output, "w");
341 if (!io.io.output) {
342 fclose(io.input);
343 return error("Could not write %s", output);
347 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
349 fclose(io.input);
350 if (io.io.wrerror)
351 error("There were errors while writing %s (%s)",
352 path, strerror(io.io.wrerror));
353 if (io.io.output && fclose(io.io.output))
354 io.io.wrerror = error("Failed to flush %s: %s",
355 path, strerror(errno));
357 if (hunk_no < 0) {
358 if (output)
359 unlink_or_warn(output);
360 return error("Could not parse conflict hunks in %s", path);
362 if (io.io.wrerror)
363 return -1;
364 return hunk_no;
368 * Subclass of rerere_io that reads from an in-core buffer that is a
369 * strbuf
371 struct rerere_io_mem {
372 struct rerere_io io;
373 struct strbuf input;
377 * ... and its getline() method implementation
379 static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
381 struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
382 char *ep;
383 size_t len;
385 strbuf_release(sb);
386 if (!io->input.len)
387 return -1;
388 ep = memchr(io->input.buf, '\n', io->input.len);
389 if (!ep)
390 ep = io->input.buf + io->input.len;
391 else if (*ep == '\n')
392 ep++;
393 len = ep - io->input.buf;
394 strbuf_add(sb, io->input.buf, len);
395 strbuf_remove(&io->input, 0, len);
396 return 0;
399 static int handle_cache(const char *path, unsigned char *sha1, const char *output)
401 mmfile_t mmfile[3] = {{NULL}};
402 mmbuffer_t result = {NULL, 0};
403 const struct cache_entry *ce;
404 int pos, len, i, hunk_no;
405 struct rerere_io_mem io;
406 int marker_size = ll_merge_marker_size(path);
409 * Reproduce the conflicted merge in-core
411 len = strlen(path);
412 pos = cache_name_pos(path, len);
413 if (0 <= pos)
414 return -1;
415 pos = -pos - 1;
417 while (pos < active_nr) {
418 enum object_type type;
419 unsigned long size;
421 ce = active_cache[pos++];
422 if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
423 break;
424 i = ce_stage(ce) - 1;
425 if (!mmfile[i].ptr) {
426 mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
427 mmfile[i].size = size;
430 for (i = 0; i < 3; i++)
431 if (!mmfile[i].ptr && !mmfile[i].size)
432 mmfile[i].ptr = xstrdup("");
435 * NEEDSWORK: handle conflicts from merges with
436 * merge.renormalize set, too
438 ll_merge(&result, path, &mmfile[0], NULL,
439 &mmfile[1], "ours",
440 &mmfile[2], "theirs", NULL);
441 for (i = 0; i < 3; i++)
442 free(mmfile[i].ptr);
444 memset(&io, 0, sizeof(io));
445 io.io.getline = rerere_mem_getline;
446 if (output)
447 io.io.output = fopen(output, "w");
448 else
449 io.io.output = NULL;
450 strbuf_init(&io.input, 0);
451 strbuf_attach(&io.input, result.ptr, result.size, result.size);
454 * Grab the conflict ID and optionally write the original
455 * contents with conflict markers out.
457 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
458 strbuf_release(&io.input);
459 if (io.io.output)
460 fclose(io.io.output);
461 return hunk_no;
465 * Look at a cache entry at "i" and see if it is not conflicting,
466 * conflicting and we are willing to handle, or conflicting and
467 * we are unable to handle, and return the determination in *type.
468 * Return the cache index to be looked at next, by skipping the
469 * stages we have already looked at in this invocation of this
470 * function.
472 static int check_one_conflict(int i, int *type)
474 const struct cache_entry *e = active_cache[i];
476 if (!ce_stage(e)) {
477 *type = RESOLVED;
478 return i + 1;
481 *type = PUNTED;
482 while (ce_stage(active_cache[i]) == 1)
483 i++;
485 /* Only handle regular files with both stages #2 and #3 */
486 if (i + 1 < active_nr) {
487 const struct cache_entry *e2 = active_cache[i];
488 const struct cache_entry *e3 = active_cache[i + 1];
489 if (ce_stage(e2) == 2 &&
490 ce_stage(e3) == 3 &&
491 ce_same_name(e, e3) &&
492 S_ISREG(e2->ce_mode) &&
493 S_ISREG(e3->ce_mode))
494 *type = THREE_STAGED;
497 /* Skip the entries with the same name */
498 while (i < active_nr && ce_same_name(e, active_cache[i]))
499 i++;
500 return i;
504 * Scan the index and find paths that have conflicts that rerere can
505 * handle, i.e. the ones that has both stages #2 and #3.
507 * NEEDSWORK: we do not record or replay a previous "resolve by
508 * deletion" for a delete-modify conflict, as that is inherently risky
509 * without knowing what modification is being discarded. The only
510 * safe case, i.e. both side doing the deletion and modification that
511 * are identical to the previous round, might want to be handled,
512 * though.
514 static int find_conflict(struct string_list *conflict)
516 int i;
517 if (read_cache() < 0)
518 return error("Could not read index");
520 for (i = 0; i < active_nr;) {
521 int conflict_type;
522 const struct cache_entry *e = active_cache[i];
523 i = check_one_conflict(i, &conflict_type);
524 if (conflict_type == THREE_STAGED)
525 string_list_insert(conflict, (const char *)e->name);
527 return 0;
531 * The merge_rr list is meant to hold outstanding conflicted paths
532 * that rerere could handle. Abuse the list by adding other types of
533 * entries to allow the caller to show "rerere remaining".
535 * - Conflicted paths that rerere does not handle are added
536 * - Conflicted paths that have been resolved are marked as such
537 * by storing RERERE_RESOLVED to .util field (where conflict ID
538 * is expected to be stored).
540 * Do *not* write MERGE_RR file out after calling this function.
542 * NEEDSWORK: we may want to fix the caller that implements "rerere
543 * remaining" to do this without abusing merge_rr.
545 int rerere_remaining(struct string_list *merge_rr)
547 int i;
548 if (setup_rerere(merge_rr, RERERE_READONLY))
549 return 0;
550 if (read_cache() < 0)
551 return error("Could not read index");
553 for (i = 0; i < active_nr;) {
554 int conflict_type;
555 const struct cache_entry *e = active_cache[i];
556 i = check_one_conflict(i, &conflict_type);
557 if (conflict_type == PUNTED)
558 string_list_insert(merge_rr, (const char *)e->name);
559 else if (conflict_type == RESOLVED) {
560 struct string_list_item *it;
561 it = string_list_lookup(merge_rr, (const char *)e->name);
562 if (it != NULL) {
563 free_rerere_id(it);
564 it->util = RERERE_RESOLVED;
568 return 0;
572 * Find the conflict identified by "id"; the change between its
573 * "preimage" (i.e. a previous contents with conflict markers) and its
574 * "postimage" (i.e. the corresponding contents with conflicts
575 * resolved) may apply cleanly to the contents stored in "path", i.e.
576 * the conflict this time around.
578 * Returns 0 for successful replay of recorded resolution, or non-zero
579 * for failure.
581 static int merge(const struct rerere_id *id, const char *path)
583 FILE *f;
584 int ret;
585 mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
586 mmbuffer_t result = {NULL, 0};
589 * Normalize the conflicts in path and write it out to
590 * "thisimage" temporary file.
592 if (handle_file(path, NULL, rerere_path(id, "thisimage")) < 0) {
593 ret = 1;
594 goto out;
597 if (read_mmfile(&cur, rerere_path(id, "thisimage")) ||
598 read_mmfile(&base, rerere_path(id, "preimage")) ||
599 read_mmfile(&other, rerere_path(id, "postimage"))) {
600 ret = 1;
601 goto out;
605 * A three-way merge. Note that this honors user-customizable
606 * low-level merge driver settings.
608 ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
609 if (ret)
610 goto out;
613 * A successful replay of recorded resolution.
614 * Mark that "postimage" was used to help gc.
616 if (utime(rerere_path(id, "postimage"), NULL) < 0)
617 warning("failed utime() on %s: %s",
618 rerere_path(id, "postimage"),
619 strerror(errno));
621 /* Update "path" with the resolution */
622 f = fopen(path, "w");
623 if (!f)
624 return error("Could not open %s: %s", path,
625 strerror(errno));
626 if (fwrite(result.ptr, result.size, 1, f) != 1)
627 error("Could not write %s: %s", path, strerror(errno));
628 if (fclose(f))
629 return error("Writing %s failed: %s", path,
630 strerror(errno));
632 out:
633 free(cur.ptr);
634 free(base.ptr);
635 free(other.ptr);
636 free(result.ptr);
638 return ret;
641 static struct lock_file index_lock;
643 static void update_paths(struct string_list *update)
645 int i;
647 hold_locked_index(&index_lock, 1);
649 for (i = 0; i < update->nr; i++) {
650 struct string_list_item *item = &update->items[i];
651 if (add_file_to_cache(item->string, 0))
652 exit(128);
653 fprintf(stderr, "Staged '%s' using previous resolution.\n",
654 item->string);
657 if (active_cache_changed) {
658 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
659 die("Unable to write new index file");
660 } else
661 rollback_lock_file(&index_lock);
665 * The path indicated by rr_item may still have conflict for which we
666 * have a recorded resolution, in which case replay it and optionally
667 * update it. Or it may have been resolved by the user and we may
668 * only have the preimage for that conflict, in which case the result
669 * needs to be recorded as a resolution in a postimage file.
671 static void do_rerere_one_path(struct string_list_item *rr_item,
672 struct string_list *update)
674 const char *path = rr_item->string;
675 const struct rerere_id *id = rr_item->util;
677 /* Is there a recorded resolution we could attempt to apply? */
678 if (has_rerere_resolution(id)) {
679 if (merge(id, path))
680 return; /* failed to replay */
682 if (rerere_autoupdate)
683 string_list_insert(update, path);
684 else
685 fprintf(stderr,
686 "Resolved '%s' using previous resolution.\n",
687 path);
688 } else if (!handle_file(path, NULL, NULL)) {
689 /* The user has resolved it. */
690 copy_file(rerere_path(id, "postimage"), path, 0666);
691 fprintf(stderr, "Recorded resolution for '%s'.\n", path);
692 } else {
693 return;
695 free_rerere_id(rr_item);
696 rr_item->util = NULL;
699 static int do_plain_rerere(struct string_list *rr, int fd)
701 struct string_list conflict = STRING_LIST_INIT_DUP;
702 struct string_list update = STRING_LIST_INIT_DUP;
703 int i;
705 find_conflict(&conflict);
708 * MERGE_RR records paths with conflicts immediately after
709 * merge failed. Some of the conflicted paths might have been
710 * hand resolved in the working tree since then, but the
711 * initial run would catch all and register their preimages.
713 for (i = 0; i < conflict.nr; i++) {
714 struct rerere_id *id;
715 unsigned char sha1[20];
716 const char *path = conflict.items[i].string;
717 int ret;
719 if (string_list_has_string(rr, path))
720 continue;
723 * Ask handle_file() to scan and assign a
724 * conflict ID. No need to write anything out
725 * yet.
727 ret = handle_file(path, sha1, NULL);
728 if (ret < 1)
729 continue;
731 id = new_rerere_id(sha1);
732 string_list_insert(rr, path)->util = id;
735 * If the directory does not exist, create
736 * it. mkdir_in_gitdir() will fail with
737 * EEXIST if there already is one.
739 * NEEDSWORK: make sure "gc" does not remove
740 * preimage without removing the directory.
742 if (mkdir_in_gitdir(rerere_path(id, NULL)))
743 continue;
746 * We are the first to encounter this
747 * conflict. Ask handle_file() to write the
748 * normalized contents to the "preimage" file.
750 handle_file(path, NULL, rerere_path(id, "preimage"));
751 fprintf(stderr, "Recorded preimage for '%s'\n", path);
754 for (i = 0; i < rr->nr; i++)
755 do_rerere_one_path(&rr->items[i], &update);
757 if (update.nr)
758 update_paths(&update);
760 return write_rr(rr, fd);
763 static void git_rerere_config(void)
765 git_config_get_bool("rerere.enabled", &rerere_enabled);
766 git_config_get_bool("rerere.autoupdate", &rerere_autoupdate);
767 git_config(git_default_config, NULL);
770 static GIT_PATH_FUNC(git_path_rr_cache, "rr-cache")
772 static int is_rerere_enabled(void)
774 int rr_cache_exists;
776 if (!rerere_enabled)
777 return 0;
779 rr_cache_exists = is_directory(git_path_rr_cache());
780 if (rerere_enabled < 0)
781 return rr_cache_exists;
783 if (!rr_cache_exists && mkdir_in_gitdir(git_path_rr_cache()))
784 die("Could not create directory %s", git_path_rr_cache());
785 return 1;
788 int setup_rerere(struct string_list *merge_rr, int flags)
790 int fd;
792 git_rerere_config();
793 if (!is_rerere_enabled())
794 return -1;
796 if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
797 rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
798 if (flags & RERERE_READONLY)
799 fd = 0;
800 else
801 fd = hold_lock_file_for_update(&write_lock, git_path_merge_rr(),
802 LOCK_DIE_ON_ERROR);
803 read_rr(merge_rr);
804 return fd;
808 * The main entry point that is called internally from codepaths that
809 * perform mergy operations, possibly leaving conflicted index entries
810 * and working tree files.
812 int rerere(int flags)
814 struct string_list merge_rr = STRING_LIST_INIT_DUP;
815 int fd;
817 fd = setup_rerere(&merge_rr, flags);
818 if (fd < 0)
819 return 0;
820 return do_plain_rerere(&merge_rr, fd);
823 static int rerere_forget_one_path(const char *path, struct string_list *rr)
825 const char *filename;
826 struct rerere_id *id;
827 unsigned char sha1[20];
828 int ret;
829 struct string_list_item *item;
832 * Recreate the original conflict from the stages in the
833 * index and compute the conflict ID
835 ret = handle_cache(path, sha1, NULL);
836 if (ret < 1)
837 return error("Could not parse conflict hunks in '%s'", path);
839 /* Nuke the recorded resolution for the conflict */
840 id = new_rerere_id(sha1);
841 filename = rerere_path(id, "postimage");
842 if (unlink(filename))
843 return (errno == ENOENT
844 ? error("no remembered resolution for %s", path)
845 : error("cannot unlink %s: %s", filename, strerror(errno)));
848 * Update the preimage so that the user can resolve the
849 * conflict in the working tree, run us again to record
850 * the postimage.
852 handle_cache(path, sha1, rerere_path(id, "preimage"));
853 fprintf(stderr, "Updated preimage for '%s'\n", path);
856 * And remember that we can record resolution for this
857 * conflict when the user is done.
859 item = string_list_insert(rr, path);
860 free_rerere_id(item);
861 item->util = id;
862 fprintf(stderr, "Forgot resolution for %s\n", path);
863 return 0;
866 int rerere_forget(struct pathspec *pathspec)
868 int i, fd;
869 struct string_list conflict = STRING_LIST_INIT_DUP;
870 struct string_list merge_rr = STRING_LIST_INIT_DUP;
872 if (read_cache() < 0)
873 return error("Could not read index");
875 fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
876 if (fd < 0)
877 return 0;
880 * The paths may have been resolved (incorrectly);
881 * recover the original conflicted state and then
882 * find the conflicted paths.
884 unmerge_cache(pathspec);
885 find_conflict(&conflict);
886 for (i = 0; i < conflict.nr; i++) {
887 struct string_list_item *it = &conflict.items[i];
888 if (!match_pathspec(pathspec, it->string,
889 strlen(it->string), 0, NULL, 0))
890 continue;
891 rerere_forget_one_path(it->string, &merge_rr);
893 return write_rr(&merge_rr, fd);
897 * Garbage collection support
901 * Note that this is not reentrant but is used only one-at-a-time
902 * so it does not matter right now.
904 static struct rerere_id *dirname_to_id(const char *name)
906 static struct rerere_id id;
907 strcpy(id.hex, name);
908 return &id;
911 static time_t rerere_created_at(const char *dir_name)
913 struct stat st;
914 struct rerere_id *id = dirname_to_id(dir_name);
916 return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
919 static time_t rerere_last_used_at(const char *dir_name)
921 struct stat st;
922 struct rerere_id *id = dirname_to_id(dir_name);
924 return stat(rerere_path(id, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
928 * Remove the recorded resolution for a given conflict ID
930 static void unlink_rr_item(struct rerere_id *id)
932 unlink(rerere_path(id, "thisimage"));
933 unlink(rerere_path(id, "preimage"));
934 unlink(rerere_path(id, "postimage"));
936 * NEEDSWORK: what if this rmdir() fails? Wouldn't we then
937 * assume that we already have preimage recorded in
938 * do_plain_rerere()?
940 rmdir(rerere_path(id, NULL));
943 void rerere_gc(struct string_list *rr)
945 struct string_list to_remove = STRING_LIST_INIT_DUP;
946 DIR *dir;
947 struct dirent *e;
948 int i, cutoff;
949 time_t now = time(NULL), then;
950 int cutoff_noresolve = 15;
951 int cutoff_resolve = 60;
953 if (setup_rerere(rr, 0) < 0)
954 return;
956 git_config_get_int("gc.rerereresolved", &cutoff_resolve);
957 git_config_get_int("gc.rerereunresolved", &cutoff_noresolve);
958 git_config(git_default_config, NULL);
959 dir = opendir(git_path("rr-cache"));
960 if (!dir)
961 die_errno("unable to open rr-cache directory");
962 /* Collect stale conflict IDs ... */
963 while ((e = readdir(dir))) {
964 if (is_dot_or_dotdot(e->d_name))
965 continue;
967 then = rerere_last_used_at(e->d_name);
968 if (then) {
969 cutoff = cutoff_resolve;
970 } else {
971 then = rerere_created_at(e->d_name);
972 if (!then)
973 continue;
974 cutoff = cutoff_noresolve;
976 if (then < now - cutoff * 86400)
977 string_list_append(&to_remove, e->d_name);
979 closedir(dir);
980 /* ... and then remove them one-by-one */
981 for (i = 0; i < to_remove.nr; i++)
982 unlink_rr_item(dirname_to_id(to_remove.items[i].string));
983 string_list_clear(&to_remove, 0);
984 rollback_lock_file(&write_lock);
988 * During a conflict resolution, after "rerere" recorded the
989 * preimages, abandon them if the user did not resolve them or
990 * record their resolutions. And drop $GIT_DIR/MERGE_RR.
992 * NEEDSWORK: shouldn't we be calling this from "reset --hard"?
994 void rerere_clear(struct string_list *merge_rr)
996 int i;
998 if (setup_rerere(merge_rr, 0) < 0)
999 return;
1001 for (i = 0; i < merge_rr->nr; i++) {
1002 struct rerere_id *id = merge_rr->items[i].util;
1003 if (!has_rerere_resolution(id))
1004 unlink_rr_item(id);
1006 unlink_or_warn(git_path_merge_rr());
1007 rollback_lock_file(&write_lock);