git-fetch-pack: really do not ask for funny refs
[git/git.git] / fetch-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "commit.h"
5 #include "tag.h"
6
7 static int keep_pack;
8 static int quiet;
9 static int verbose;
10 static const char fetch_pack_usage[] =
11 "git-fetch-pack [-q] [-v] [-k] [--exec=upload-pack] [host:]directory <refs>...";
12 static const char *exec = "git-upload-pack";
13
14 #define COMPLETE (1U << 0)
15 #define COMMON (1U << 1)
16 #define COMMON_REF (1U << 2)
17 #define SEEN (1U << 3)
18 #define POPPED (1U << 4)
19
20 static struct commit_list *rev_list = NULL;
21 static int non_common_revs = 0, multi_ack = 0;
22
23 static void rev_list_push(struct commit *commit, int mark)
24 {
25 if (!(commit->object.flags & mark)) {
26 commit->object.flags |= mark;
27
28 if (!(commit->object.parsed))
29 parse_commit(commit);
30
31 insert_by_date(commit, &rev_list);
32
33 if (!(commit->object.flags & COMMON))
34 non_common_revs++;
35 }
36 }
37
38 static int rev_list_insert_ref(const char *path, const unsigned char *sha1)
39 {
40 struct object *o = deref_tag(parse_object(sha1), path, 0);
41
42 if (o && o->type == commit_type)
43 rev_list_push((struct commit *)o, SEEN);
44
45 return 0;
46 }
47
48 /*
49 This function marks a rev and its ancestors as common.
50 In some cases, it is desirable to mark only the ancestors (for example
51 when only the server does not yet know that they are common).
52 */
53
54 static void mark_common(struct commit *commit,
55 int ancestors_only, int dont_parse)
56 {
57 if (commit != NULL && !(commit->object.flags & COMMON)) {
58 struct object *o = (struct object *)commit;
59
60 if (!ancestors_only)
61 o->flags |= COMMON;
62
63 if (!(o->flags & SEEN))
64 rev_list_push(commit, SEEN);
65 else {
66 struct commit_list *parents;
67
68 if (!ancestors_only && !(o->flags & POPPED))
69 non_common_revs--;
70 if (!o->parsed && !dont_parse)
71 parse_commit(commit);
72
73 for (parents = commit->parents;
74 parents;
75 parents = parents->next)
76 mark_common(parents->item, 0, dont_parse);
77 }
78 }
79 }
80
81 /*
82 Get the next rev to send, ignoring the common.
83 */
84
85 static const unsigned char* get_rev()
86 {
87 struct commit *commit = NULL;
88
89 while (commit == NULL) {
90 unsigned int mark;
91 struct commit_list* parents;
92
93 if (rev_list == NULL || non_common_revs == 0)
94 return NULL;
95
96 commit = rev_list->item;
97 if (!(commit->object.parsed))
98 parse_commit(commit);
99 commit->object.flags |= POPPED;
100 if (!(commit->object.flags & COMMON))
101 non_common_revs--;
102
103 parents = commit->parents;
104
105 if (commit->object.flags & COMMON) {
106 /* do not send "have", and ignore ancestors */
107 commit = NULL;
108 mark = COMMON | SEEN;
109 } else if (commit->object.flags & COMMON_REF)
110 /* send "have", and ignore ancestors */
111 mark = COMMON | SEEN;
112 else
113 /* send "have", also for its ancestors */
114 mark = SEEN;
115
116 while (parents) {
117 if (!(parents->item->object.flags & SEEN))
118 rev_list_push(parents->item, mark);
119 if (mark & COMMON)
120 mark_common(parents->item, 1, 0);
121 parents = parents->next;
122 }
123
124 rev_list = rev_list->next;
125 }
126
127 return commit->object.sha1;
128 }
129
130 static int find_common(int fd[2], unsigned char *result_sha1,
131 struct ref *refs)
132 {
133 int fetching;
134 int count = 0, flushes = 0, retval;
135 const unsigned char *sha1;
136
137 for_each_ref(rev_list_insert_ref);
138
139 fetching = 0;
140 for ( ; refs ; refs = refs->next) {
141 unsigned char *remote = refs->old_sha1;
142 struct object *o;
143
144 /*
145 * If that object is complete (i.e. it is an ancestor of a
146 * local ref), we tell them we have it but do not have to
147 * tell them about its ancestors, which they already know
148 * about.
149 *
150 * We use lookup_object here because we are only
151 * interested in the case we *know* the object is
152 * reachable and we have already scanned it.
153 */
154 if (((o = lookup_object(remote)) != NULL) &&
155 (o->flags & COMPLETE)) {
156 continue;
157 }
158
159 packet_write(fd[1], "want %s%s\n", sha1_to_hex(remote),
160 multi_ack ? " multi_ack" : "");
161 fetching++;
162 }
163 packet_flush(fd[1]);
164 if (!fetching)
165 return 1;
166
167 flushes = 0;
168 retval = -1;
169 while ((sha1 = get_rev())) {
170 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
171 if (verbose)
172 fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
173 if (!(31 & ++count)) {
174 int ack;
175
176 packet_flush(fd[1]);
177 flushes++;
178
179 /*
180 * We keep one window "ahead" of the other side, and
181 * will wait for an ACK only on the next one
182 */
183 if (count == 32)
184 continue;
185
186 do {
187 ack = get_ack(fd[0], result_sha1);
188 if (verbose && ack)
189 fprintf(stderr, "got ack %d %s\n", ack,
190 sha1_to_hex(result_sha1));
191 if (ack == 1) {
192 flushes = 0;
193 multi_ack = 0;
194 retval = 0;
195 goto done;
196 } else if (ack == 2) {
197 struct commit *commit =
198 lookup_commit(result_sha1);
199 mark_common(commit, 0, 1);
200 retval = 0;
201 }
202 } while (ack);
203 flushes--;
204 }
205 }
206 done:
207 packet_write(fd[1], "done\n");
208 if (verbose)
209 fprintf(stderr, "done\n");
210 if (retval != 0) {
211 multi_ack = 0;
212 flushes++;
213 }
214 while (flushes || multi_ack) {
215 int ack = get_ack(fd[0], result_sha1);
216 if (ack) {
217 if (verbose)
218 fprintf(stderr, "got ack (%d) %s\n", ack,
219 sha1_to_hex(result_sha1));
220 if (ack == 1)
221 return 0;
222 multi_ack = 1;
223 continue;
224 }
225 flushes--;
226 }
227 return retval;
228 }
229
230 static struct commit_list *complete = NULL;
231
232 static int mark_complete(const char *path, const unsigned char *sha1)
233 {
234 struct object *o = parse_object(sha1);
235
236 while (o && o->type == tag_type) {
237 struct tag *t = (struct tag *) o;
238 if (!t->tagged)
239 break; /* broken repository */
240 o->flags |= COMPLETE;
241 o = parse_object(t->tagged->sha1);
242 }
243 if (o && o->type == commit_type) {
244 struct commit *commit = (struct commit *)o;
245 commit->object.flags |= COMPLETE;
246 insert_by_date(commit, &complete);
247 }
248 return 0;
249 }
250
251 static void mark_recent_complete_commits(unsigned long cutoff)
252 {
253 while (complete && cutoff <= complete->item->date) {
254 if (verbose)
255 fprintf(stderr, "Marking %s as complete\n",
256 sha1_to_hex(complete->item->object.sha1));
257 pop_most_recent_commit(&complete, COMPLETE);
258 }
259 }
260
261 static void filter_refs(struct ref **refs, int nr_match, char **match)
262 {
263 struct ref *prev, *current, *next;
264
265 for (prev = NULL, current = *refs; current; current = next) {
266 next = current->next;
267 if ((!memcmp(current->name, "refs/", 5) &&
268 check_ref_format(current->name + 5)) ||
269 !path_match(current->name, nr_match, match)) {
270 if (prev == NULL)
271 *refs = next;
272 else
273 prev->next = next;
274 free(current);
275 } else
276 prev = current;
277 }
278 }
279
280 static int everything_local(struct ref **refs, int nr_match, char **match)
281 {
282 struct ref *ref;
283 int retval;
284 unsigned long cutoff = 0;
285
286 track_object_refs = 0;
287 save_commit_buffer = 0;
288
289 for (ref = *refs; ref; ref = ref->next) {
290 struct object *o;
291
292 o = parse_object(ref->old_sha1);
293 if (!o)
294 continue;
295
296 /* We already have it -- which may mean that we were
297 * in sync with the other side at some time after
298 * that (it is OK if we guess wrong here).
299 */
300 if (o->type == commit_type) {
301 struct commit *commit = (struct commit *)o;
302 if (!cutoff || cutoff < commit->date)
303 cutoff = commit->date;
304 }
305 }
306
307 for_each_ref(mark_complete);
308 if (cutoff)
309 mark_recent_complete_commits(cutoff);
310
311 /*
312 * Mark all complete remote refs as common refs.
313 * Don't mark them common yet; the server has to be told so first.
314 */
315 for (ref = *refs; ref; ref = ref->next) {
316 struct object *o = deref_tag(lookup_object(ref->old_sha1),
317 NULL, 0);
318
319 if (!o || o->type != commit_type || !(o->flags & COMPLETE))
320 continue;
321
322 if (!(o->flags & SEEN)) {
323 rev_list_push((struct commit *)o, COMMON_REF | SEEN);
324
325 mark_common((struct commit *)o, 1, 1);
326 }
327 }
328
329 filter_refs(refs, nr_match, match);
330
331 for (retval = 1, ref = *refs; ref ; ref = ref->next) {
332 const unsigned char *remote = ref->old_sha1;
333 unsigned char local[20];
334 struct object *o;
335
336 o = lookup_object(remote);
337 if (!o || !(o->flags & COMPLETE)) {
338 retval = 0;
339 if (!verbose)
340 continue;
341 fprintf(stderr,
342 "want %s (%s)\n", sha1_to_hex(remote),
343 ref->name);
344 continue;
345 }
346
347 memcpy(ref->new_sha1, local, 20);
348 if (!verbose)
349 continue;
350 fprintf(stderr,
351 "already have %s (%s)\n", sha1_to_hex(remote),
352 ref->name);
353 }
354 return retval;
355 }
356
357 static int fetch_pack(int fd[2], int nr_match, char **match)
358 {
359 struct ref *ref;
360 unsigned char sha1[20];
361 int status;
362
363 get_remote_heads(fd[0], &ref, 0, NULL, 0);
364 if (server_supports("multi_ack")) {
365 if (verbose)
366 fprintf(stderr, "Server supports multi_ack\n");
367 multi_ack = 1;
368 }
369 if (!ref) {
370 packet_flush(fd[1]);
371 die("no matching remote head");
372 }
373 if (everything_local(&ref, nr_match, match)) {
374 packet_flush(fd[1]);
375 goto all_done;
376 }
377 if (find_common(fd, sha1, ref) < 0)
378 fprintf(stderr, "warning: no common commits\n");
379
380 if (keep_pack)
381 status = receive_keep_pack(fd, "git-fetch-pack");
382 else
383 status = receive_unpack_pack(fd, "git-fetch-pack", quiet);
384
385 if (status)
386 die("git-fetch-pack: fetch failed.");
387
388 all_done:
389 while (ref) {
390 printf("%s %s\n",
391 sha1_to_hex(ref->old_sha1), ref->name);
392 ref = ref->next;
393 }
394 return 0;
395 }
396
397 int main(int argc, char **argv)
398 {
399 int i, ret, nr_heads;
400 char *dest = NULL, **heads;
401 int fd[2];
402 pid_t pid;
403
404 setup_git_directory();
405
406 nr_heads = 0;
407 heads = NULL;
408 for (i = 1; i < argc; i++) {
409 char *arg = argv[i];
410
411 if (*arg == '-') {
412 if (!strncmp("--exec=", arg, 7)) {
413 exec = arg + 7;
414 continue;
415 }
416 if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
417 quiet = 1;
418 continue;
419 }
420 if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
421 keep_pack = 1;
422 continue;
423 }
424 if (!strcmp("-v", arg)) {
425 verbose = 1;
426 continue;
427 }
428 usage(fetch_pack_usage);
429 }
430 dest = arg;
431 heads = argv + i + 1;
432 nr_heads = argc - i - 1;
433 break;
434 }
435 if (!dest)
436 usage(fetch_pack_usage);
437 pid = git_connect(fd, dest, exec);
438 if (pid < 0)
439 return 1;
440 ret = fetch_pack(fd, nr_heads, heads);
441 close(fd[0]);
442 close(fd[1]);
443 finish_connect(pid);
444
445 if (!ret && nr_heads) {
446 /* If the heads to pull were given, we should have
447 * consumed all of them by matching the remote.
448 * Otherwise, 'git-fetch remote no-such-ref' would
449 * silently succeed without issuing an error.
450 */
451 for (i = 0; i < nr_heads; i++)
452 if (heads[i] && heads[i][0]) {
453 error("no such remote ref %s", heads[i]);
454 ret = 1;
455 }
456 }
457
458 return ret;
459 }