Merge branch 'jc/diffopt'
[git/jrn.git] / builtin-rerere.c
blob8c2c8bdc18a69e4dff7386548e5f7ea78a133f7b
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)
19 return git_path("rr-cache/%s/%s", name, file);
22 static void read_rr(struct path_list *rr)
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);
44 fclose(in);
47 static struct lock_file write_lock;
49 static int write_rr(struct path_list *rr, int out_fd)
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");
60 close(out_fd);
61 return commit_lock_file(&write_lock);
64 struct buffer {
65 char *ptr;
66 int nr, alloc;
69 static void append_line(struct buffer *buffer, const char *line)
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);
77 memcpy(buffer->ptr + buffer->nr, line, len);
78 buffer->nr += len;
81 static void clear_buffer(struct buffer *buffer)
83 free(buffer->ptr);
84 buffer->ptr = NULL;
85 buffer->nr = buffer->alloc = 0;
88 static int handle_file(const char *path,
89 unsigned char *sha1, const char *output)
91 SHA_CTX ctx;
92 char buf[1024];
93 int hunk = 0, hunk_no = 0;
94 struct buffer minus = { NULL, 0, 0 }, plus = { NULL, 0, 0 };
95 struct buffer *one = &minus, *two = &plus;
96 FILE *f = fopen(path, "r");
97 FILE *out;
99 if (!f)
100 return error("Could not open %s", path);
102 if (output) {
103 out = fopen(output, "w");
104 if (!out) {
105 fclose(f);
106 return error("Could not write %s", output);
108 } else
109 out = NULL;
111 if (sha1)
112 SHA1_Init(&ctx);
114 while (fgets(buf, sizeof(buf), f)) {
115 if (!prefixcmp(buf, "<<<<<<< "))
116 hunk = 1;
117 else if (!prefixcmp(buf, "======="))
118 hunk = 2;
119 else if (!prefixcmp(buf, ">>>>>>> ")) {
120 int one_is_longer = (one->nr > two->nr);
121 int common_len = one_is_longer ? two->nr : one->nr;
122 int cmp = memcmp(one->ptr, two->ptr, common_len);
124 hunk_no++;
125 hunk = 0;
126 if ((cmp > 0) || ((cmp == 0) && one_is_longer)) {
127 struct buffer *swap = one;
128 one = two;
129 two = swap;
131 if (out) {
132 fputs("<<<<<<<\n", out);
133 fwrite(one->ptr, one->nr, 1, out);
134 fputs("=======\n", out);
135 fwrite(two->ptr, two->nr, 1, out);
136 fputs(">>>>>>>\n", out);
138 if (sha1) {
139 SHA1_Update(&ctx, one->ptr, one->nr);
140 SHA1_Update(&ctx, "\0", 1);
141 SHA1_Update(&ctx, two->ptr, two->nr);
142 SHA1_Update(&ctx, "\0", 1);
144 clear_buffer(one);
145 clear_buffer(two);
146 } else if (hunk == 1)
147 append_line(one, buf);
148 else if (hunk == 2)
149 append_line(two, buf);
150 else if (out)
151 fputs(buf, out);
154 fclose(f);
155 if (out)
156 fclose(out);
157 if (sha1)
158 SHA1_Final(sha1, &ctx);
159 return hunk_no;
162 static int find_conflict(struct path_list *conflict)
164 int i;
165 if (read_cache() < 0)
166 return error("Could not read index");
167 for (i = 0; i + 2 < active_nr; i++) {
168 struct cache_entry *e1 = active_cache[i];
169 struct cache_entry *e2 = active_cache[i+1];
170 struct cache_entry *e3 = active_cache[i+2];
171 if (ce_stage(e1) == 1 &&
172 ce_stage(e2) == 2 &&
173 ce_stage(e3) == 3 &&
174 ce_same_name(e1, e2) && ce_same_name(e1, e3) &&
175 S_ISREG(ntohl(e1->ce_mode)) &&
176 S_ISREG(ntohl(e2->ce_mode)) &&
177 S_ISREG(ntohl(e3->ce_mode))) {
178 path_list_insert((const char *)e1->name, conflict);
179 i += 2;
182 return 0;
185 static int merge(const char *name, const char *path)
187 int ret;
188 mmfile_t cur, base, other;
189 mmbuffer_t result = {NULL, 0};
190 xpparam_t xpp = {XDF_NEED_MINIMAL};
192 if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
193 return 1;
195 if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
196 read_mmfile(&base, rr_path(name, "preimage")) ||
197 read_mmfile(&other, rr_path(name, "postimage")))
198 return 1;
199 ret = xdl_merge(&base, &cur, "", &other, "",
200 &xpp, XDL_MERGE_ZEALOUS, &result);
201 if (!ret) {
202 FILE *f = fopen(path, "w");
203 if (!f)
204 return error("Could not write to %s", path);
205 fwrite(result.ptr, result.size, 1, f);
206 fclose(f);
209 free(cur.ptr);
210 free(base.ptr);
211 free(other.ptr);
212 free(result.ptr);
214 return ret;
217 static void unlink_rr_item(const char *name)
219 unlink(rr_path(name, "thisimage"));
220 unlink(rr_path(name, "preimage"));
221 unlink(rr_path(name, "postimage"));
222 rmdir(git_path("rr-cache/%s", name));
225 static void garbage_collect(struct path_list *rr)
227 struct path_list to_remove = { NULL, 0, 0, 1 };
228 char buf[1024];
229 DIR *dir;
230 struct dirent *e;
231 int len, i, cutoff;
232 time_t now = time(NULL), then;
234 strlcpy(buf, git_path("rr-cache"), sizeof(buf));
235 len = strlen(buf);
236 dir = opendir(buf);
237 strcpy(buf + len++, "/");
238 while ((e = readdir(dir))) {
239 const char *name = e->d_name;
240 struct stat st;
241 if (name[0] == '.' && (name[1] == '\0' ||
242 (name[1] == '.' && name[2] == '\0')))
243 continue;
244 i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
245 strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
246 if (stat(buf, &st))
247 continue;
248 then = st.st_mtime;
249 strlcpy(buf + len + i, "/postimage", sizeof(buf) - len - i);
250 cutoff = stat(buf, &st) ? cutoff_noresolve : cutoff_resolve;
251 if (then < now - cutoff * 86400) {
252 buf[len + i] = '\0';
253 path_list_insert(xstrdup(name), &to_remove);
256 for (i = 0; i < to_remove.nr; i++)
257 unlink_rr_item(to_remove.items[i].path);
258 path_list_clear(&to_remove, 0);
261 static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
263 int i;
264 for (i = 0; i < nbuf; i++)
265 if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
266 return -1;
267 return 0;
270 static int diff_two(const char *file1, const char *label1,
271 const char *file2, const char *label2)
273 xpparam_t xpp;
274 xdemitconf_t xecfg;
275 xdemitcb_t ecb;
276 mmfile_t minus, plus;
278 if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
279 return 1;
281 printf("--- a/%s\n+++ b/%s\n", label1, label2);
282 fflush(stdout);
283 xpp.flags = XDF_NEED_MINIMAL;
284 xecfg.ctxlen = 3;
285 xecfg.flags = 0;
286 ecb.outf = outf;
287 xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
289 free(minus.ptr);
290 free(plus.ptr);
291 return 0;
294 static int copy_file(const char *src, const char *dest)
296 FILE *in, *out;
297 char buffer[32768];
298 int count;
300 if (!(in = fopen(src, "r")))
301 return error("Could not open %s", src);
302 if (!(out = fopen(dest, "w")))
303 return error("Could not open %s", dest);
304 while ((count = fread(buffer, 1, sizeof(buffer), in)))
305 fwrite(buffer, 1, count, out);
306 fclose(in);
307 fclose(out);
308 return 0;
311 static int do_plain_rerere(struct path_list *rr, int fd)
313 struct path_list conflict = { NULL, 0, 0, 1 };
314 int i;
316 find_conflict(&conflict);
319 * MERGE_RR records paths with conflicts immediately after merge
320 * failed. Some of the conflicted paths might have been hand resolved
321 * in the working tree since then, but the initial run would catch all
322 * and register their preimages.
325 for (i = 0; i < conflict.nr; i++) {
326 const char *path = conflict.items[i].path;
327 if (!path_list_has_path(rr, path)) {
328 unsigned char sha1[20];
329 char *hex;
330 int ret;
331 ret = handle_file(path, sha1, NULL);
332 if (ret < 1)
333 continue;
334 hex = xstrdup(sha1_to_hex(sha1));
335 path_list_insert(path, rr)->util = hex;
336 if (mkdir(git_path("rr-cache/%s", hex), 0755))
337 continue;;
338 handle_file(path, NULL, rr_path(hex, "preimage"));
339 fprintf(stderr, "Recorded preimage for '%s'\n", path);
344 * Now some of the paths that had conflicts earlier might have been
345 * hand resolved. Others may be similar to a conflict already that
346 * was resolved before.
349 for (i = 0; i < rr->nr; i++) {
350 struct stat st;
351 int ret;
352 const char *path = rr->items[i].path;
353 const char *name = (const char *)rr->items[i].util;
355 if (!stat(rr_path(name, "preimage"), &st) &&
356 !stat(rr_path(name, "postimage"), &st)) {
357 if (!merge(name, path)) {
358 fprintf(stderr, "Resolved '%s' using "
359 "previous resolution.\n", path);
360 goto tail_optimization;
364 /* Let's see if we have resolved it. */
365 ret = handle_file(path, NULL, NULL);
366 if (ret)
367 continue;
369 fprintf(stderr, "Recorded resolution for '%s'.\n", path);
370 copy_file(path, rr_path(name, "postimage"));
371 tail_optimization:
372 if (i < rr->nr - 1)
373 memmove(rr->items + i,
374 rr->items + i + 1,
375 sizeof(rr->items[0]) * (rr->nr - i - 1));
376 rr->nr--;
377 i--;
380 return write_rr(rr, fd);
383 static int git_rerere_config(const char *var, const char *value)
385 if (!strcmp(var, "gc.rerereresolved"))
386 cutoff_resolve = git_config_int(var, value);
387 else if (!strcmp(var, "gc.rerereunresolved"))
388 cutoff_noresolve = git_config_int(var, value);
389 else
390 return git_default_config(var, value);
391 return 0;
394 int cmd_rerere(int argc, const char **argv, const char *prefix)
396 struct path_list merge_rr = { NULL, 0, 0, 1 };
397 int i, fd = -1;
398 struct stat st;
400 if (stat(git_path("rr-cache"), &st) || !S_ISDIR(st.st_mode))
401 return 0;
403 git_config(git_rerere_config);
405 merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
406 fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
407 read_rr(&merge_rr);
409 if (argc < 2)
410 return do_plain_rerere(&merge_rr, fd);
411 else if (!strcmp(argv[1], "clear")) {
412 for (i = 0; i < merge_rr.nr; i++) {
413 const char *name = (const char *)merge_rr.items[i].util;
414 if (!stat(git_path("rr-cache/%s", name), &st) &&
415 S_ISDIR(st.st_mode) &&
416 stat(rr_path(name, "postimage"), &st))
417 unlink_rr_item(name);
419 unlink(merge_rr_path);
420 } else if (!strcmp(argv[1], "gc"))
421 garbage_collect(&merge_rr);
422 else if (!strcmp(argv[1], "status"))
423 for (i = 0; i < merge_rr.nr; i++)
424 printf("%s\n", merge_rr.items[i].path);
425 else if (!strcmp(argv[1], "diff"))
426 for (i = 0; i < merge_rr.nr; i++) {
427 const char *path = merge_rr.items[i].path;
428 const char *name = (const char *)merge_rr.items[i].util;
429 diff_two(rr_path(name, "preimage"), path, path, path);
431 else
432 usage(git_rerere_usage);
434 path_list_clear(&merge_rr, 1);
435 return 0;