1 #include "cache.h"
2 #include "path-list.h"
3 #include "xdiff/xdiff.h"
4 #include "xdiff-interface.h"
6 #include <time.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 static char *merge_rr_path;
17 static const char *rr_path(const char *name, const char *file)
18 {
19 return git_path("rr-cache/%s/%s", name, file);
20 }
22 static void read_rr(struct path_list *rr)
23 {
24 unsigned char sha1[20];
25 char buf[PATH_MAX];
26 FILE *in = fopen(merge_rr_path, "r");
27 if (!in)
28 return;
29 while (fread(buf, 40, 1, in) == 1) {
30 int i;
31 char *name;
32 if (get_sha1_hex(buf, sha1))
33 die("corrupt MERGE_RR");
34 buf[40] = '\0';
35 name = xstrdup(buf);
36 if (fgetc(in) != '\t')
37 die("corrupt MERGE_RR");
38 for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
39 ; /* do nothing */
40 if (i == sizeof(buf))
41 die("filename too long");
42 path_list_insert(buf, rr)->util = xstrdup(name);
43 }
44 fclose(in);
45 }
47 static struct lock_file write_lock;
49 static int write_rr(struct path_list *rr, int out_fd)
50 {
51 int i;
52 for (i = 0; i < rr->nr; i++) {
53 const char *path = rr->items[i].path;
54 int length = strlen(path) + 1;
55 if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
56 write_in_full(out_fd, "\t", 1) != 1 ||
57 write_in_full(out_fd, path, length) != length)
58 die("unable to write rerere record");
59 }
60 close(out_fd);
61 return commit_lock_file(&write_lock);
62 }
64 struct buffer {
65 char *ptr;
66 int nr, alloc;
67 };
69 static void append_line(struct buffer *buffer, const char *line)
70 {
71 int len = strlen(line);
73 if (buffer->nr + len > buffer->alloc) {
74 buffer->alloc = alloc_nr(buffer->nr + len);
75 buffer->ptr = xrealloc(buffer->ptr, buffer->alloc);
76 }
77 memcpy(buffer->ptr + buffer->nr, line, len);
78 buffer->nr += len;
79 }
81 static int handle_file(const char *path,
82 unsigned char *sha1, const char *output)
83 {
84 SHA_CTX ctx;
85 char buf[1024];
86 int hunk = 0, hunk_no = 0;
87 struct buffer minus = { NULL, 0, 0 }, plus = { NULL, 0, 0 };
88 struct buffer *one = &minus, *two = +
89 FILE *f = fopen(path, "r");
90 FILE *out;
92 if (!f)
93 return error("Could not open %s", path);
95 if (output) {
96 out = fopen(output, "w");
97 if (!out) {
98 fclose(f);
99 return error("Could not write %s", output);
100 }
101 } else
102 out = NULL;
104 if (sha1)
105 SHA1_Init(&ctx);
107 while (fgets(buf, sizeof(buf), f)) {
108 if (!prefixcmp(buf, "<<<<<<< "))
109 hunk = 1;
110 else if (!prefixcmp(buf, "======="))
111 hunk = 2;
112 else if (!prefixcmp(buf, ">>>>>>> ")) {
113 hunk_no++;
114 hunk = 0;
115 if (memcmp(one->ptr, two->ptr, one->nr < two->nr ?
116 one->nr : two->nr) > 0) {
117 struct buffer *swap = one;
118 one = two;
119 two = swap;
120 }
121 if (out) {
122 fputs("<<<<<<<\n", out);
123 fwrite(one->ptr, one->nr, 1, out);
124 fputs("=======\n", out);
125 fwrite(two->ptr, two->nr, 1, out);
126 fputs(">>>>>>>\n", out);
127 }
128 if (sha1) {
129 SHA1_Update(&ctx, one->ptr, one->nr);
130 SHA1_Update(&ctx, "\0", 1);
131 SHA1_Update(&ctx, two->ptr, two->nr);
132 SHA1_Update(&ctx, "\0", 1);
133 }
134 } else if (hunk == 1)
135 append_line(one, buf);
136 else if (hunk == 2)
137 append_line(two, buf);
138 else if (out)
139 fputs(buf, out);
140 }
142 fclose(f);
143 if (out)
144 fclose(out);
145 if (sha1)
146 SHA1_Final(sha1, &ctx);
147 return hunk_no;
148 }
150 static int find_conflict(struct path_list *conflict)
151 {
152 int i;
153 if (read_cache() < 0)
154 return error("Could not read index");
155 for (i = 0; i + 2 < active_nr; i++) {
156 struct cache_entry *e1 = active_cache[i];
157 struct cache_entry *e2 = active_cache[i+1];
158 struct cache_entry *e3 = active_cache[i+2];
159 if (ce_stage(e1) == 1 &&
160 ce_stage(e2) == 2 &&
161 ce_stage(e3) == 3 &&
162 ce_same_name(e1, e2) && ce_same_name(e1, e3) &&
163 S_ISREG(ntohl(e1->ce_mode)) &&
164 S_ISREG(ntohl(e2->ce_mode)) &&
165 S_ISREG(ntohl(e3->ce_mode))) {
166 path_list_insert((const char *)e1->name, conflict);
167 i += 2;
168 }
169 }
170 return 0;
171 }
173 static int merge(const char *name, const char *path)
174 {
175 int ret;
176 mmfile_t cur, base, other;
177 mmbuffer_t result = {NULL, 0};
178 xpparam_t xpp = {XDF_NEED_MINIMAL};
180 if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
181 return 1;
183 if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
184 read_mmfile(&base, rr_path(name, "preimage")) ||
185 read_mmfile(&other, rr_path(name, "postimage")))
186 return 1;
187 ret = xdl_merge(&base, &cur, "", &other, "",
188 &xpp, XDL_MERGE_ZEALOUS, &result);
189 if (!ret) {
190 FILE *f = fopen(path, "w");
191 if (!f)
192 return error("Could not write to %s", path);
193 fwrite(result.ptr, result.size, 1, f);
194 fclose(f);
195 }
197 free(cur.ptr);
198 free(base.ptr);
199 free(other.ptr);
200 free(result.ptr);
202 return ret;
203 }
205 static void unlink_rr_item(const char *name)
206 {
207 unlink(rr_path(name, "thisimage"));
208 unlink(rr_path(name, "preimage"));
209 unlink(rr_path(name, "postimage"));
210 rmdir(git_path("rr-cache/%s", name));
211 }
213 static void garbage_collect(struct path_list *rr)
214 {
215 struct path_list to_remove = { NULL, 0, 0, 1 };
216 char buf[1024];
217 DIR *dir;
218 struct dirent *e;
219 int len, i, cutoff;
220 time_t now = time(NULL), then;
222 strlcpy(buf, git_path("rr-cache"), sizeof(buf));
223 len = strlen(buf);
224 dir = opendir(buf);
225 strcpy(buf + len++, "/");
226 while ((e = readdir(dir))) {
227 const char *name = e->d_name;
228 struct stat st;
229 if (name[0] == '.' && (name[1] == '\0' ||
230 (name[1] == '.' && name[2] == '\0')))
231 continue;
232 i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
233 strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
234 if (stat(buf, &st))
235 continue;
236 then = st.st_mtime;
237 strlcpy(buf + len + i, "/postimage", sizeof(buf) - len - i);
238 cutoff = stat(buf, &st) ? cutoff_noresolve : cutoff_resolve;
239 if (then < now - cutoff * 86400) {
240 buf[len + i] = '\0';
241 path_list_insert(xstrdup(name), &to_remove);
242 }
243 }
244 for (i = 0; i < to_remove.nr; i++)
245 unlink_rr_item(to_remove.items[i].path);
246 path_list_clear(&to_remove, 0);
247 }
249 static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
250 {
251 int i;
252 for (i = 0; i < nbuf; i++)
253 if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
254 return -1;
255 return 0;
256 }
258 static int diff_two(const char *file1, const char *label1,
259 const char *file2, const char *label2)
260 {
261 xpparam_t xpp;
262 xdemitconf_t xecfg;
263 xdemitcb_t ecb;
264 mmfile_t minus, plus;
266 if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
267 return 1;
269 printf("--- a/%s\n+++ b/%s\n", label1, label2);
270 fflush(stdout);
271 xpp.flags = XDF_NEED_MINIMAL;
272 xecfg.ctxlen = 3;
273 xecfg.flags = 0;
274 ecb.outf = outf;
275 xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
277 free(minus.ptr);
278 free(plus.ptr);
279 return 0;
280 }
282 static int copy_file(const char *src, const char *dest)
283 {
284 FILE *in, *out;
285 char buffer[32768];
286 int count;
288 if (!(in = fopen(src, "r")))
289 return error("Could not open %s", src);
290 if (!(out = fopen(dest, "w")))
291 return error("Could not open %s", dest);
292 while ((count = fread(buffer, 1, sizeof(buffer), in)))
293 fwrite(buffer, 1, count, out);
294 fclose(in);
295 fclose(out);
296 return 0;
297 }
299 static int do_plain_rerere(struct path_list *rr, int fd)
300 {
301 struct path_list conflict = { NULL, 0, 0, 1 };
302 int i;
304 find_conflict(&conflict);
306 /*
307 * MERGE_RR records paths with conflicts immediately after merge
308 * failed. Some of the conflicted paths might have been hand resolved
309 * in the working tree since then, but the initial run would catch all
310 * and register their preimages.
311 */
313 for (i = 0; i < conflict.nr; i++) {
314 const char *path = conflict.items[i].path;
315 if (!path_list_has_path(rr, path)) {
316 unsigned char sha1[20];
317 char *hex;
318 int ret;
319 ret = handle_file(path, sha1, NULL);
320 if (ret < 1)
321 continue;
322 hex = xstrdup(sha1_to_hex(sha1));
323 path_list_insert(path, rr)->util = hex;
324 if (mkdir(git_path("rr-cache/%s", hex), 0755))
325 continue;;
326 handle_file(path, NULL, rr_path(hex, "preimage"));
327 fprintf(stderr, "Recorded preimage for '%s'\n", path);
328 }
329 }
331 /*
332 * Now some of the paths that had conflicts earlier might have been
333 * hand resolved. Others may be similar to a conflict already that
334 * was resolved before.
335 */
337 for (i = 0; i < rr->nr; i++) {
338 struct stat st;
339 int ret;
340 const char *path = rr->items[i].path;
341 const char *name = (const char *)rr->items[i].util;
343 if (!stat(rr_path(name, "preimage"), &st) &&
344 !stat(rr_path(name, "postimage"), &st)) {
345 if (!merge(name, path)) {
346 fprintf(stderr, "Resolved '%s' using "
347 "previous resolution.\n", path);
348 goto tail_optimization;
349 }
350 }
352 /* Let's see if we have resolved it. */
353 ret = handle_file(path, NULL, NULL);
354 if (ret)
355 continue;
357 fprintf(stderr, "Recorded resolution for '%s'.\n", path);
358 copy_file(path, rr_path(name, "postimage"));
359 tail_optimization:
360 if (i < rr->nr - 1)
361 memmove(rr->items + i,
362 rr->items + i + 1,
363 sizeof(rr->items[0]) * (rr->nr - i - 1));
364 rr->nr--;
365 i--;
366 }
368 return write_rr(rr, fd);
369 }
371 static int git_rerere_config(const char *var, const char *value)
372 {
373 if (!strcmp(var, "gc.rerereresolved"))
374 cutoff_resolve = git_config_int(var, value);
375 else if (!strcmp(var, "gc.rerereunresolved"))
376 cutoff_noresolve = git_config_int(var, value);
377 else
378 return git_default_config(var, value);
379 return 0;
380 }
382 int cmd_rerere(int argc, const char **argv, const char *prefix)
383 {
384 struct path_list merge_rr = { NULL, 0, 0, 1 };
385 int i, fd = -1;
386 struct stat st;
388 if (stat(git_path("rr-cache"), &st) || !S_ISDIR(st.st_mode))
389 return 0;
391 git_config(git_rerere_config);
393 merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
394 fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
395 read_rr(&merge_rr);
397 if (argc < 2)
398 return do_plain_rerere(&merge_rr, fd);
399 else if (!strcmp(argv[1], "clear")) {
400 for (i = 0; i < merge_rr.nr; i++) {
401 const char *name = (const char *)merge_rr.items[i].util;
402 if (!stat(git_path("rr-cache/%s", name), &st) &&
403 S_ISDIR(st.st_mode) &&
404 stat(rr_path(name, "postimage"), &st))
405 unlink_rr_item(name);
406 }
407 unlink(merge_rr_path);
408 } else if (!strcmp(argv[1], "gc"))
409 garbage_collect(&merge_rr);
410 else if (!strcmp(argv[1], "status"))
411 for (i = 0; i < merge_rr.nr; i++)
412 printf("%s\n", merge_rr.items[i].path);
413 else if (!strcmp(argv[1], "diff"))
414 for (i = 0; i < merge_rr.nr; i++) {
415 const char *path = merge_rr.items[i].path;
416 const char *name = (const char *)merge_rr.items[i].util;
417 diff_two(rr_path(name, "preimage"), path, path, path);
418 }
419 else
420 usage(git_rerere_usage);
422 path_list_clear(&merge_rr, 1);
423 return 0;
424 }