3 #include "xdiff/xdiff.h"
4 #include "xdiff-interface.h"
8 static const char git_rerere_usage[] =
9 "git-rerere [clear | status | diff | gc]";
11 /* these values are days */
12 static int cutoff_noresolve = 15;
13 static int cutoff_resolve = 60;
15 /* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
16 static int rerere_enabled = -1;
18 static char *merge_rr_path;
20 static const char *rr_path(const char *name, const char *file)
22 return git_path("rr-cache/%s/%s", name, file);
25 static void read_rr(struct path_list *rr)
27 unsigned char sha1[20];
29 FILE *in = fopen(merge_rr_path, "r");
32 while (fread(buf, 40, 1, in) == 1) {
35 if (get_sha1_hex(buf, sha1))
36 die("corrupt MERGE_RR");
39 if (fgetc(in) != '\t')
40 die("corrupt MERGE_RR");
41 for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
44 die("filename too long");
45 path_list_insert(buf, rr)->util = xstrdup(name);
50 static struct lock_file write_lock;
52 static int write_rr(struct path_list *rr, int out_fd)
55 for (i = 0; i < rr->nr; i++) {
56 const char *path = rr->items[i].path;
57 int length = strlen(path) + 1;
58 if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
59 write_in_full(out_fd, "\t", 1) != 1 ||
60 write_in_full(out_fd, path, length) != length)
61 die("unable to write rerere record");
63 if (close(out_fd) != 0)
64 die("unable to write rerere record");
65 return commit_lock_file(&write_lock);
73 static void append_line(struct buffer *buffer, const char *line)
75 int len = strlen(line);
77 if (buffer->nr + len > buffer->alloc) {
78 buffer->alloc = alloc_nr(buffer->nr + len);
79 buffer->ptr = xrealloc(buffer->ptr, buffer->alloc);
81 memcpy(buffer->ptr + buffer->nr, line, len);
85 static void clear_buffer(struct buffer *buffer)
89 buffer->nr = buffer->alloc = 0;
92 static int handle_file(const char *path,
93 unsigned char *sha1, const char *output)
97 int hunk = 0, hunk_no = 0;
98 struct buffer minus = { NULL, 0, 0 }, plus = { NULL, 0, 0 };
99 struct buffer *one = &minus, *two = +
100 FILE *f = fopen(path, "r");
104 return error("Could not open %s", path);
107 out = fopen(output, "w");
110 return error("Could not write %s", output);
118 while (fgets(buf, sizeof(buf), f)) {
119 if (!prefixcmp(buf, "<<<<<<< "))
121 else if (!prefixcmp(buf, "======="))
123 else if (!prefixcmp(buf, ">>>>>>> ")) {
124 int one_is_longer = (one->nr > two->nr);
125 int common_len = one_is_longer ? two->nr : one->nr;
126 int cmp = memcmp(one->ptr, two->ptr, common_len);
130 if ((cmp > 0) || ((cmp == 0) && one_is_longer)) {
131 struct buffer *swap = one;
136 fputs("<<<<<<<\n", out);
137 fwrite(one->ptr, one->nr, 1, out);
138 fputs("=======\n", out);
139 fwrite(two->ptr, two->nr, 1, out);
140 fputs(">>>>>>>\n", out);
143 SHA1_Update(&ctx, one->ptr, one->nr);
144 SHA1_Update(&ctx, "\0", 1);
145 SHA1_Update(&ctx, two->ptr, two->nr);
146 SHA1_Update(&ctx, "\0", 1);
150 } else if (hunk == 1)
151 append_line(one, buf);
153 append_line(two, buf);
162 SHA1_Final(sha1, &ctx);
166 static int find_conflict(struct path_list *conflict)
169 if (read_cache() < 0)
170 return error("Could not read index");
171 for (i = 0; i+1 < active_nr; i++) {
172 struct cache_entry *e2 = active_cache[i];
173 struct cache_entry *e3 = active_cache[i+1];
174 if (ce_stage(e2) == 2 &&
176 ce_same_name(e2, e3) &&
177 S_ISREG(ntohl(e2->ce_mode)) &&
178 S_ISREG(ntohl(e3->ce_mode))) {
179 path_list_insert((const char *)e2->name, conflict);
180 i++; /* skip over both #2 and #3 */
186 static int merge(const char *name, const char *path)
189 mmfile_t cur, base, other;
190 mmbuffer_t result = {NULL, 0};
191 xpparam_t xpp = {XDF_NEED_MINIMAL};
193 if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
196 if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
197 read_mmfile(&base, rr_path(name, "preimage")) ||
198 read_mmfile(&other, rr_path(name, "postimage")))
200 ret = xdl_merge(&base, &cur, "", &other, "",
201 &xpp, XDL_MERGE_ZEALOUS, &result);
203 FILE *f = fopen(path, "w");
205 return error("Could not write to %s", path);
206 fwrite(result.ptr, result.size, 1, f);
218 static void unlink_rr_item(const char *name)
220 unlink(rr_path(name, "thisimage"));
221 unlink(rr_path(name, "preimage"));
222 unlink(rr_path(name, "postimage"));
223 rmdir(git_path("rr-cache/%s", name));
226 static void garbage_collect(struct path_list *rr)
228 struct path_list to_remove = { NULL, 0, 0, 1 };
233 time_t now = time(NULL), then;
235 strlcpy(buf, git_path("rr-cache"), sizeof(buf));
238 strcpy(buf + len++, "/");
239 while ((e = readdir(dir))) {
240 const char *name = e->d_name;
242 if (name[0] == '.' && (name[1] == '\0' ||
243 (name[1] == '.' && name[2] == '\0')))
245 i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
246 strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
250 strlcpy(buf + len + i, "/postimage", sizeof(buf) - len - i);
251 cutoff = stat(buf, &st) ? cutoff_noresolve : cutoff_resolve;
252 if (then < now - cutoff * 86400) {
254 path_list_insert(xstrdup(name), &to_remove);
257 for (i = 0; i < to_remove.nr; i++)
258 unlink_rr_item(to_remove.items[i].path);
259 path_list_clear(&to_remove, 0);
262 static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
265 for (i = 0; i < nbuf; i++)
266 if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
271 static int diff_two(const char *file1, const char *label1,
272 const char *file2, const char *label2)
277 mmfile_t minus, plus;
279 if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
282 printf("--- a/%s\n+++ b/%s\n", label1, label2);
284 xpp.flags = XDF_NEED_MINIMAL;
285 memset(&xecfg, 0, sizeof(xecfg));
288 xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
295 static int copy_file(const char *src, const char *dest)
301 if (!(in = fopen(src, "r")))
302 return error("Could not open %s", src);
303 if (!(out = fopen(dest, "w")))
304 return error("Could not open %s", dest);
305 while ((count = fread(buffer, 1, sizeof(buffer), in)))
306 fwrite(buffer, 1, count, out);
312 static int do_plain_rerere(struct path_list *rr, int fd)
314 struct path_list conflict = { NULL, 0, 0, 1 };
317 find_conflict(&conflict);
320 * MERGE_RR records paths with conflicts immediately after merge
321 * failed. Some of the conflicted paths might have been hand resolved
322 * in the working tree since then, but the initial run would catch all
323 * and register their preimages.
326 for (i = 0; i < conflict.nr; i++) {
327 const char *path = conflict.items[i].path;
328 if (!path_list_has_path(rr, path)) {
329 unsigned char sha1[20];
332 ret = handle_file(path, sha1, NULL);
335 hex = xstrdup(sha1_to_hex(sha1));
336 path_list_insert(path, rr)->util = hex;
337 if (mkdir(git_path("rr-cache/%s", hex), 0755))
339 handle_file(path, NULL, rr_path(hex, "preimage"));
340 fprintf(stderr, "Recorded preimage for '%s'\n", path);
345 * Now some of the paths that had conflicts earlier might have been
346 * hand resolved. Others may be similar to a conflict already that
347 * was resolved before.
350 for (i = 0; i < rr->nr; i++) {
353 const char *path = rr->items[i].path;
354 const char *name = (const char *)rr->items[i].util;
356 if (!stat(rr_path(name, "preimage"), &st) &&
357 !stat(rr_path(name, "postimage"), &st)) {
358 if (!merge(name, path)) {
359 fprintf(stderr, "Resolved '%s' using "
360 "previous resolution.\n", path);
361 goto tail_optimization;
365 /* Let's see if we have resolved it. */
366 ret = handle_file(path, NULL, NULL);
370 fprintf(stderr, "Recorded resolution for '%s'.\n", path);
371 copy_file(path, rr_path(name, "postimage"));
374 memmove(rr->items + i,
376 sizeof(rr->items[0]) * (rr->nr - i - 1));
381 return write_rr(rr, fd);
384 static int git_rerere_config(const char *var, const char *value)
386 if (!strcmp(var, "gc.rerereresolved"))
387 cutoff_resolve = git_config_int(var, value);
388 else if (!strcmp(var, "gc.rerereunresolved"))
389 cutoff_noresolve = git_config_int(var, value);
390 else if (!strcmp(var, "rerere.enabled"))
391 rerere_enabled = git_config_bool(var, value);
393 return git_default_config(var, value);
397 static int is_rerere_enabled(void)
400 const char *rr_cache;
406 rr_cache = git_path("rr-cache");
407 rr_cache_exists = !stat(rr_cache, &st) && S_ISDIR(st.st_mode);
408 if (rerere_enabled < 0)
409 return rr_cache_exists;
411 if (!rr_cache_exists &&
412 (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
413 die("Could not create directory %s", rr_cache);
417 int cmd_rerere(int argc, const char **argv, const char *prefix)
419 struct path_list merge_rr = { NULL, 0, 0, 1 };
422 git_config(git_rerere_config);
423 if (!is_rerere_enabled())
426 merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
427 fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
431 return do_plain_rerere(&merge_rr, fd);
432 else if (!strcmp(argv[1], "clear")) {
433 for (i = 0; i < merge_rr.nr; i++) {
435 const char *name = (const char *)merge_rr.items[i].util;
436 if (!stat(git_path("rr-cache/%s", name), &st) &&
437 S_ISDIR(st.st_mode) &&
438 stat(rr_path(name, "postimage"), &st))
439 unlink_rr_item(name);
441 unlink(merge_rr_path);
442 } else if (!strcmp(argv[1], "gc"))
443 garbage_collect(&merge_rr);
444 else if (!strcmp(argv[1], "status"))
445 for (i = 0; i < merge_rr.nr; i++)
446 printf("%s\n", merge_rr.items[i].path);
447 else if (!strcmp(argv[1], "diff"))
448 for (i = 0; i < merge_rr.nr; i++) {
449 const char *path = merge_rr.items[i].path;
450 const char *name = (const char *)merge_rr.items[i].util;
451 diff_two(rr_path(name, "preimage"), path, path, path);
454 usage(git_rerere_usage);
456 path_list_clear(&merge_rr, 1);