Merge branch 'rs/fix-alt-odb-path-comparison' into maint
[git.git] / rerere.c
blobd55aa8a01b4a4f200f24972795f2887644a06d43
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 #include "pathspec.h"
11 #define RESOLVED 0
12 #define PUNTED 1
13 #define THREE_STAGED 2
14 void *RERERE_RESOLVED = &RERERE_RESOLVED;
16 /* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
17 static int rerere_enabled = -1;
19 /* automatically update cleanly resolved paths to the index */
20 static int rerere_autoupdate;
22 static char *merge_rr_path;
24 const char *rerere_path(const char *hex, const char *file)
26 return git_path("rr-cache/%s/%s", hex, file);
29 static int has_rerere_resolution(const char *hex)
31 struct stat st;
32 return !stat(rerere_path(hex, "postimage"), &st);
35 static void read_rr(struct string_list *rr)
37 unsigned char sha1[20];
38 char buf[PATH_MAX];
39 FILE *in = fopen(merge_rr_path, "r");
40 if (!in)
41 return;
42 while (fread(buf, 40, 1, in) == 1) {
43 int i;
44 char *name;
45 if (get_sha1_hex(buf, sha1))
46 die("corrupt MERGE_RR");
47 buf[40] = '\0';
48 name = xstrdup(buf);
49 if (fgetc(in) != '\t')
50 die("corrupt MERGE_RR");
51 for (i = 0; i < sizeof(buf); i++) {
52 int c = fgetc(in);
53 if (c < 0)
54 die("corrupt MERGE_RR");
55 buf[i] = c;
56 if (c == 0)
57 break;
59 if (i == sizeof(buf))
60 die("filename too long");
61 string_list_insert(rr, buf)->util = name;
63 fclose(in);
66 static struct lock_file write_lock;
68 static int write_rr(struct string_list *rr, int out_fd)
70 int i;
71 for (i = 0; i < rr->nr; i++) {
72 const char *path;
73 int length;
74 if (!rr->items[i].util)
75 continue;
76 path = rr->items[i].string;
77 length = strlen(path) + 1;
78 if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
79 write_str_in_full(out_fd, "\t") != 1 ||
80 write_in_full(out_fd, path, length) != length)
81 die("unable to write rerere record");
83 if (commit_lock_file(&write_lock) != 0)
84 die("unable to write rerere record");
85 return 0;
88 static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
90 if (!count || *err)
91 return;
92 if (fwrite(p, count, 1, fp) != 1)
93 *err = errno;
96 static inline void ferr_puts(const char *s, FILE *fp, int *err)
98 ferr_write(s, strlen(s), fp, err);
101 struct rerere_io {
102 int (*getline)(struct strbuf *, struct rerere_io *);
103 FILE *output;
104 int wrerror;
105 /* some more stuff */
108 static void rerere_io_putstr(const char *str, struct rerere_io *io)
110 if (io->output)
111 ferr_puts(str, io->output, &io->wrerror);
114 static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
116 char buf[64];
118 while (size) {
119 if (size < sizeof(buf) - 2) {
120 memset(buf, ch, size);
121 buf[size] = '\n';
122 buf[size + 1] = '\0';
123 size = 0;
124 } else {
125 int sz = sizeof(buf) - 1;
126 if (size <= sz)
127 sz -= (sz - size) + 1;
128 memset(buf, ch, sz);
129 buf[sz] = '\0';
130 size -= sz;
132 rerere_io_putstr(buf, io);
136 static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
138 if (io->output)
139 ferr_write(mem, sz, io->output, &io->wrerror);
142 struct rerere_io_file {
143 struct rerere_io io;
144 FILE *input;
147 static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
149 struct rerere_io_file *io = (struct rerere_io_file *)io_;
150 return strbuf_getwholeline(sb, io->input, '\n');
153 static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
155 while (marker_size--)
156 if (*buf++ != marker_char)
157 return 0;
158 if (want_sp && *buf != ' ')
159 return 0;
160 return isspace(*buf);
163 static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
165 git_SHA_CTX ctx;
166 int hunk_no = 0;
167 enum {
168 RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
169 } hunk = RR_CONTEXT;
170 struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
171 struct strbuf buf = STRBUF_INIT;
173 if (sha1)
174 git_SHA1_Init(&ctx);
176 while (!io->getline(&buf, io)) {
177 if (is_cmarker(buf.buf, '<', marker_size, 1)) {
178 if (hunk != RR_CONTEXT)
179 goto bad;
180 hunk = RR_SIDE_1;
181 } else if (is_cmarker(buf.buf, '|', marker_size, 0)) {
182 if (hunk != RR_SIDE_1)
183 goto bad;
184 hunk = RR_ORIGINAL;
185 } else if (is_cmarker(buf.buf, '=', marker_size, 0)) {
186 if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
187 goto bad;
188 hunk = RR_SIDE_2;
189 } else if (is_cmarker(buf.buf, '>', marker_size, 1)) {
190 if (hunk != RR_SIDE_2)
191 goto bad;
192 if (strbuf_cmp(&one, &two) > 0)
193 strbuf_swap(&one, &two);
194 hunk_no++;
195 hunk = RR_CONTEXT;
196 rerere_io_putconflict('<', marker_size, io);
197 rerere_io_putmem(one.buf, one.len, io);
198 rerere_io_putconflict('=', marker_size, io);
199 rerere_io_putmem(two.buf, two.len, io);
200 rerere_io_putconflict('>', marker_size, io);
201 if (sha1) {
202 git_SHA1_Update(&ctx, one.buf ? one.buf : "",
203 one.len + 1);
204 git_SHA1_Update(&ctx, two.buf ? two.buf : "",
205 two.len + 1);
207 strbuf_reset(&one);
208 strbuf_reset(&two);
209 } else if (hunk == RR_SIDE_1)
210 strbuf_addstr(&one, buf.buf);
211 else if (hunk == RR_ORIGINAL)
212 ; /* discard */
213 else if (hunk == RR_SIDE_2)
214 strbuf_addstr(&two, buf.buf);
215 else
216 rerere_io_putstr(buf.buf, io);
217 continue;
218 bad:
219 hunk = 99; /* force error exit */
220 break;
222 strbuf_release(&one);
223 strbuf_release(&two);
224 strbuf_release(&buf);
226 if (sha1)
227 git_SHA1_Final(sha1, &ctx);
228 if (hunk != RR_CONTEXT)
229 return -1;
230 return hunk_no;
233 static int handle_file(const char *path, unsigned char *sha1, const char *output)
235 int hunk_no = 0;
236 struct rerere_io_file io;
237 int marker_size = ll_merge_marker_size(path);
239 memset(&io, 0, sizeof(io));
240 io.io.getline = rerere_file_getline;
241 io.input = fopen(path, "r");
242 io.io.wrerror = 0;
243 if (!io.input)
244 return error("Could not open %s", path);
246 if (output) {
247 io.io.output = fopen(output, "w");
248 if (!io.io.output) {
249 fclose(io.input);
250 return error("Could not write %s", output);
254 hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
256 fclose(io.input);
257 if (io.io.wrerror)
258 error("There were errors while writing %s (%s)",
259 path, strerror(io.io.wrerror));
260 if (io.io.output && fclose(io.io.output))
261 io.io.wrerror = error("Failed to flush %s: %s",
262 path, strerror(errno));
264 if (hunk_no < 0) {
265 if (output)
266 unlink_or_warn(output);
267 return error("Could not parse conflict hunks in %s", path);
269 if (io.io.wrerror)
270 return -1;
271 return hunk_no;
274 struct rerere_io_mem {
275 struct rerere_io io;
276 struct strbuf input;
279 static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
281 struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
282 char *ep;
283 size_t len;
285 strbuf_release(sb);
286 if (!io->input.len)
287 return -1;
288 ep = memchr(io->input.buf, '\n', io->input.len);
289 if (!ep)
290 ep = io->input.buf + io->input.len;
291 else if (*ep == '\n')
292 ep++;
293 len = ep - io->input.buf;
294 strbuf_add(sb, io->input.buf, len);
295 strbuf_remove(&io->input, 0, len);
296 return 0;
299 static int handle_cache(const char *path, unsigned char *sha1, const char *output)
301 mmfile_t mmfile[3] = {{NULL}};
302 mmbuffer_t result = {NULL, 0};
303 const struct cache_entry *ce;
304 int pos, len, i, hunk_no;
305 struct rerere_io_mem io;
306 int marker_size = ll_merge_marker_size(path);
309 * Reproduce the conflicted merge in-core
311 len = strlen(path);
312 pos = cache_name_pos(path, len);
313 if (0 <= pos)
314 return -1;
315 pos = -pos - 1;
317 for (i = 0; i < 3; i++) {
318 enum object_type type;
319 unsigned long size;
320 int j;
322 if (active_nr <= pos)
323 break;
324 ce = active_cache[pos++];
325 if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
326 continue;
327 j = ce_stage(ce) - 1;
328 mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size);
329 mmfile[j].size = size;
331 for (i = 0; i < 3; i++) {
332 if (!mmfile[i].ptr && !mmfile[i].size)
333 mmfile[i].ptr = xstrdup("");
336 * NEEDSWORK: handle conflicts from merges with
337 * merge.renormalize set, too
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);
345 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);
354 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;
361 static int check_one_conflict(int i, int *type)
363 const struct cache_entry *e = active_cache[i];
365 if (!ce_stage(e)) {
366 *type = RESOLVED;
367 return i + 1;
370 *type = PUNTED;
371 if (ce_stage(e) == 1) {
372 if (active_nr <= ++i)
373 return i + 1;
376 /* Only handle regular files with both stages #2 and #3 */
377 if (i + 1 < active_nr) {
378 const struct cache_entry *e2 = active_cache[i];
379 const 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;
388 /* Skip the entries with the same name */
389 while (i < active_nr && ce_same_name(e, active_cache[i]))
390 i++;
391 return i;
394 static int find_conflict(struct string_list *conflict)
396 int i;
397 if (read_cache() < 0)
398 return error("Could not read index");
400 for (i = 0; i < active_nr;) {
401 int conflict_type;
402 const 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);
407 return 0;
410 int rerere_remaining(struct string_list *merge_rr)
412 int i;
413 if (read_cache() < 0)
414 return error("Could not read index");
416 for (i = 0; i < active_nr;) {
417 int conflict_type;
418 const 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;
431 return 0;
434 static int merge(const char *name, const char *path)
436 int ret;
437 mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
438 mmbuffer_t result = {NULL, 0};
440 if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
441 return 1;
443 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;
449 ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
450 if (!ret) {
451 FILE *f;
453 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));
468 out:
469 free(cur.ptr);
470 free(base.ptr);
471 free(other.ptr);
472 free(result.ptr);
474 return ret;
477 static struct lock_file index_lock;
479 static int update_paths(struct string_list *update)
481 int i;
482 int fd = hold_locked_index(&index_lock, 0);
483 int status = 0;
485 if (fd < 0)
486 return -1;
488 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;
494 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;
503 static int do_plain_rerere(struct string_list *rr, int fd)
505 struct string_list conflict = STRING_LIST_INIT_DUP;
506 struct string_list update = STRING_LIST_INIT_DUP;
507 int i;
509 find_conflict(&conflict);
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.
518 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);
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.
542 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;
547 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;
560 /* Let's see if we have resolved it. */
561 ret = handle_file(path, NULL, NULL);
562 if (ret)
563 continue;
565 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;
571 if (update.nr)
572 update_paths(&update);
574 return write_rr(rr, fd);
577 static int git_rerere_config(const char *var, const char *value, void *cb)
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;
588 static int is_rerere_enabled(void)
590 const char *rr_cache;
591 int rr_cache_exists;
593 if (!rerere_enabled)
594 return 0;
596 rr_cache = git_path("rr-cache");
597 rr_cache_exists = is_directory(rr_cache);
598 if (rerere_enabled < 0)
599 return rr_cache_exists;
601 if (!rr_cache_exists && mkdir_in_gitdir(rr_cache))
602 die("Could not create directory %s", rr_cache);
603 return 1;
606 int setup_rerere(struct string_list *merge_rr, int flags)
608 int fd;
610 git_config(git_rerere_config, NULL);
611 if (!is_rerere_enabled())
612 return -1;
614 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;
623 int rerere(int flags)
625 struct string_list merge_rr = STRING_LIST_INIT_DUP;
626 int fd;
628 fd = setup_rerere(&merge_rr, flags);
629 if (fd < 0)
630 return 0;
631 return do_plain_rerere(&merge_rr, fd);
634 static int rerere_forget_one_path(const char *path, struct string_list *rr)
636 const char *filename;
637 char *hex;
638 unsigned char sha1[20];
639 int ret;
641 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)));
651 handle_cache(path, sha1, rerere_path(hex, "preimage"));
652 fprintf(stderr, "Updated preimage for '%s'\n", path);
655 string_list_insert(rr, path)->util = hex;
656 fprintf(stderr, "Forgot resolution for %s\n", path);
657 return 0;
660 int rerere_forget(struct pathspec *pathspec)
662 int i, fd;
663 struct string_list conflict = STRING_LIST_INIT_DUP;
664 struct string_list merge_rr = STRING_LIST_INIT_DUP;
666 if (read_cache() < 0)
667 return error("Could not read index");
669 fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
671 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,
676 strlen(it->string), 0, NULL, 0))
677 continue;
678 rerere_forget_one_path(it->string, &merge_rr);
680 return write_rr(&merge_rr, fd);
683 static time_t rerere_created_at(const char *name)
685 struct stat st;
686 return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
689 static time_t rerere_last_used_at(const char *name)
691 struct stat st;
692 return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
695 static void unlink_rr_item(const char *name)
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));
703 struct rerere_gc_config_cb {
704 int cutoff_noresolve;
705 int cutoff_resolve;
708 static int git_rerere_gc_config(const char *var, const char *value, void *cb)
710 struct rerere_gc_config_cb *cf = cb;
712 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;
721 void rerere_gc(struct string_list *rr)
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 };
730 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;
738 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;
747 if (then < now - cutoff * 86400)
748 string_list_append(&to_remove, e->d_name);
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);
756 void rerere_clear(struct string_list *merge_rr)
758 int i;
760 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);
765 unlink_or_warn(git_path("MERGE_RR"));