upload-pack: Move the revision walker into a separate function.
[git/git.git] / upload-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "sideband.h"
5 #include "tag.h"
6 #include "object.h"
7 #include "commit.h"
8 #include "exec_cmd.h"
9 #include "diff.h"
10 #include "revision.h"
11 #include "list-objects.h"
12 #include "run-command.h"
13
14 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
15
16 /* bits #0..7 in revision.h, #8..10 in commit.c */
17 #define THEY_HAVE (1u << 11)
18 #define OUR_REF (1u << 12)
19 #define WANTED (1u << 13)
20 #define COMMON_KNOWN (1u << 14)
21 #define REACHABLE (1u << 15)
22
23 #define SHALLOW (1u << 16)
24 #define NOT_SHALLOW (1u << 17)
25 #define CLIENT_SHALLOW (1u << 18)
26
27 static unsigned long oldest_have;
28
29 static int multi_ack, nr_our_refs;
30 static int use_thin_pack, use_ofs_delta, no_progress;
31 static struct object_array have_obj;
32 static struct object_array want_obj;
33 static unsigned int timeout;
34 /* 0 for no sideband,
35 * otherwise maximum packet size (up to 65520 bytes).
36 */
37 static int use_sideband;
38
39 static void reset_timeout(void)
40 {
41 alarm(timeout);
42 }
43
44 static int strip(char *line, int len)
45 {
46 if (len && line[len-1] == '\n')
47 line[--len] = 0;
48 return len;
49 }
50
51 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
52 {
53 if (use_sideband)
54 return send_sideband(1, fd, data, sz, use_sideband);
55 if (fd == 3)
56 /* emergency quit */
57 fd = 2;
58 if (fd == 2) {
59 /* XXX: are we happy to lose stuff here? */
60 xwrite(fd, data, sz);
61 return sz;
62 }
63 return safe_write(fd, data, sz);
64 }
65
66 static FILE *pack_pipe = NULL;
67 static void show_commit(struct commit *commit)
68 {
69 if (commit->object.flags & BOUNDARY)
70 fputc('-', pack_pipe);
71 if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
72 die("broken output pipe");
73 fputc('\n', pack_pipe);
74 fflush(pack_pipe);
75 free(commit->buffer);
76 commit->buffer = NULL;
77 }
78
79 static void show_object(struct object_array_entry *p)
80 {
81 /* An object with name "foo\n0000000..." can be used to
82 * confuse downstream git-pack-objects very badly.
83 */
84 const char *ep = strchr(p->name, '\n');
85 if (ep) {
86 fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
87 (int) (ep - p->name),
88 p->name);
89 }
90 else
91 fprintf(pack_pipe, "%s %s\n",
92 sha1_to_hex(p->item->sha1), p->name);
93 }
94
95 static void show_edge(struct commit *commit)
96 {
97 fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
98 }
99
100 static void do_rev_list(int create_full_pack)
101 {
102 int i;
103 struct rev_info revs;
104
105 if (create_full_pack)
106 use_thin_pack = 0; /* no point doing it */
107 init_revisions(&revs, NULL);
108 revs.tag_objects = 1;
109 revs.tree_objects = 1;
110 revs.blob_objects = 1;
111 if (use_thin_pack)
112 revs.edge_hint = 1;
113
114 if (create_full_pack) {
115 const char *args[] = {"rev-list", "--all", NULL};
116 setup_revisions(2, args, &revs, NULL);
117 } else {
118 for (i = 0; i < want_obj.nr; i++) {
119 struct object *o = want_obj.objects[i].item;
120 /* why??? */
121 o->flags &= ~UNINTERESTING;
122 add_pending_object(&revs, o, NULL);
123 }
124 for (i = 0; i < have_obj.nr; i++) {
125 struct object *o = have_obj.objects[i].item;
126 o->flags |= UNINTERESTING;
127 add_pending_object(&revs, o, NULL);
128 }
129 setup_revisions(0, NULL, &revs, NULL);
130 }
131 prepare_revision_walk(&revs);
132 mark_edges_uninteresting(revs.commits, &revs, show_edge);
133 traverse_commit_list(&revs, show_commit, show_object);
134 }
135
136 static void create_pack_file(void)
137 {
138 /* Pipe from rev-list to pack-objects
139 */
140 int lp_pipe[2];
141 pid_t pid_rev_list;
142 struct child_process pack_objects;
143 int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
144 char data[8193], progress[128];
145 char abort_msg[] = "aborting due to possible repository "
146 "corruption on the remote side.";
147 int buffered = -1;
148 const char *argv[10];
149 int arg = 0;
150
151 if (pipe(lp_pipe) < 0)
152 die("git-upload-pack: unable to create pipe");
153 pid_rev_list = fork();
154 if (pid_rev_list < 0)
155 die("git-upload-pack: unable to fork git-rev-list");
156
157 if (!pid_rev_list) {
158 close(lp_pipe[0]);
159 pack_pipe = fdopen(lp_pipe[1], "w");
160 do_rev_list(create_full_pack);
161 exit(0);
162 }
163
164 /* writable pipe end must not be inherited by pack_objects */
165 close(lp_pipe[1]);
166
167 argv[arg++] = "pack-objects";
168 argv[arg++] = "--stdout";
169 if (!no_progress)
170 argv[arg++] = "--progress";
171 if (use_ofs_delta)
172 argv[arg++] = "--delta-base-offset";
173 argv[arg++] = NULL;
174
175 memset(&pack_objects, 0, sizeof(pack_objects));
176 pack_objects.in = lp_pipe[0]; /* start_command closes it */
177 pack_objects.out = -1;
178 pack_objects.err = -1;
179 pack_objects.git_cmd = 1;
180 pack_objects.argv = argv;
181 if (start_command(&pack_objects)) {
182 /* daemon sets things up to ignore TERM */
183 kill(pid_rev_list, SIGKILL);
184 die("git-upload-pack: unable to fork git-pack-objects");
185 }
186
187 /* We read from pack_objects.err to capture stderr output for
188 * progress bar, and pack_objects.out to capture the pack data.
189 */
190
191 while (1) {
192 const char *who;
193 struct pollfd pfd[2];
194 pid_t pid;
195 int status;
196 ssize_t sz;
197 int pe, pu, pollsize;
198
199 reset_timeout();
200
201 pollsize = 0;
202 pe = pu = -1;
203
204 if (0 <= pack_objects.out) {
205 pfd[pollsize].fd = pack_objects.out;
206 pfd[pollsize].events = POLLIN;
207 pu = pollsize;
208 pollsize++;
209 }
210 if (0 <= pack_objects.err) {
211 pfd[pollsize].fd = pack_objects.err;
212 pfd[pollsize].events = POLLIN;
213 pe = pollsize;
214 pollsize++;
215 }
216
217 if (pollsize) {
218 if (poll(pfd, pollsize, -1) < 0) {
219 if (errno != EINTR) {
220 error("poll failed, resuming: %s",
221 strerror(errno));
222 sleep(1);
223 }
224 continue;
225 }
226 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
227 /* Data ready; we keep the last byte
228 * to ourselves in case we detect
229 * broken rev-list, so that we can
230 * leave the stream corrupted. This
231 * is unfortunate -- unpack-objects
232 * would happily accept a valid pack
233 * data with trailing garbage, so
234 * appending garbage after we pass all
235 * the pack data is not good enough to
236 * signal breakage to downstream.
237 */
238 char *cp = data;
239 ssize_t outsz = 0;
240 if (0 <= buffered) {
241 *cp++ = buffered;
242 outsz++;
243 }
244 sz = xread(pack_objects.out, cp,
245 sizeof(data) - outsz);
246 if (0 < sz)
247 ;
248 else if (sz == 0) {
249 close(pack_objects.out);
250 pack_objects.out = -1;
251 }
252 else
253 goto fail;
254 sz += outsz;
255 if (1 < sz) {
256 buffered = data[sz-1] & 0xFF;
257 sz--;
258 }
259 else
260 buffered = -1;
261 sz = send_client_data(1, data, sz);
262 if (sz < 0)
263 goto fail;
264 }
265 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
266 /* Status ready; we ship that in the side-band
267 * or dump to the standard error.
268 */
269 sz = xread(pack_objects.err, progress,
270 sizeof(progress));
271 if (0 < sz)
272 send_client_data(2, progress, sz);
273 else if (sz == 0) {
274 close(pack_objects.err);
275 pack_objects.err = -1;
276 }
277 else
278 goto fail;
279 }
280 }
281
282 /* See if the children are still there */
283 if (pid_rev_list || pack_objects.pid) {
284 pid = waitpid(-1, &status, WNOHANG);
285 if (!pid)
286 continue;
287 who = ((pid == pid_rev_list) ? "git-rev-list" :
288 (pid == pack_objects.pid) ? "git-pack-objects" :
289 NULL);
290 if (!who) {
291 if (pid < 0) {
292 error("git-upload-pack: %s",
293 strerror(errno));
294 goto fail;
295 }
296 error("git-upload-pack: we weren't "
297 "waiting for %d", pid);
298 continue;
299 }
300 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
301 error("git-upload-pack: %s died with error.",
302 who);
303 goto fail;
304 }
305 if (pid == pid_rev_list)
306 pid_rev_list = 0;
307 if (pid == pack_objects.pid)
308 pack_objects.pid = 0;
309 if (pid_rev_list || pack_objects.pid)
310 continue;
311 }
312
313 /* both died happily */
314 if (pollsize)
315 continue;
316
317 /* flush the data */
318 if (0 <= buffered) {
319 data[0] = buffered;
320 sz = send_client_data(1, data, 1);
321 if (sz < 0)
322 goto fail;
323 fprintf(stderr, "flushed.\n");
324 }
325 if (use_sideband)
326 packet_flush(1);
327 return;
328 }
329 fail:
330 if (pack_objects.pid)
331 kill(pack_objects.pid, SIGKILL);
332 if (pid_rev_list)
333 kill(pid_rev_list, SIGKILL);
334 send_client_data(3, abort_msg, sizeof(abort_msg));
335 die("git-upload-pack: %s", abort_msg);
336 }
337
338 static int got_sha1(char *hex, unsigned char *sha1)
339 {
340 struct object *o;
341 int we_knew_they_have = 0;
342
343 if (get_sha1_hex(hex, sha1))
344 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
345 if (!has_sha1_file(sha1))
346 return -1;
347
348 o = lookup_object(sha1);
349 if (!(o && o->parsed))
350 o = parse_object(sha1);
351 if (!o)
352 die("oops (%s)", sha1_to_hex(sha1));
353 if (o->type == OBJ_COMMIT) {
354 struct commit_list *parents;
355 struct commit *commit = (struct commit *)o;
356 if (o->flags & THEY_HAVE)
357 we_knew_they_have = 1;
358 else
359 o->flags |= THEY_HAVE;
360 if (!oldest_have || (commit->date < oldest_have))
361 oldest_have = commit->date;
362 for (parents = commit->parents;
363 parents;
364 parents = parents->next)
365 parents->item->object.flags |= THEY_HAVE;
366 }
367 if (!we_knew_they_have) {
368 add_object_array(o, NULL, &have_obj);
369 return 1;
370 }
371 return 0;
372 }
373
374 static int reachable(struct commit *want)
375 {
376 struct commit_list *work = NULL;
377
378 insert_by_date(want, &work);
379 while (work) {
380 struct commit_list *list = work->next;
381 struct commit *commit = work->item;
382 free(work);
383 work = list;
384
385 if (commit->object.flags & THEY_HAVE) {
386 want->object.flags |= COMMON_KNOWN;
387 break;
388 }
389 if (!commit->object.parsed)
390 parse_object(commit->object.sha1);
391 if (commit->object.flags & REACHABLE)
392 continue;
393 commit->object.flags |= REACHABLE;
394 if (commit->date < oldest_have)
395 continue;
396 for (list = commit->parents; list; list = list->next) {
397 struct commit *parent = list->item;
398 if (!(parent->object.flags & REACHABLE))
399 insert_by_date(parent, &work);
400 }
401 }
402 want->object.flags |= REACHABLE;
403 clear_commit_marks(want, REACHABLE);
404 free_commit_list(work);
405 return (want->object.flags & COMMON_KNOWN);
406 }
407
408 static int ok_to_give_up(void)
409 {
410 int i;
411
412 if (!have_obj.nr)
413 return 0;
414
415 for (i = 0; i < want_obj.nr; i++) {
416 struct object *want = want_obj.objects[i].item;
417
418 if (want->flags & COMMON_KNOWN)
419 continue;
420 want = deref_tag(want, "a want line", 0);
421 if (!want || want->type != OBJ_COMMIT) {
422 /* no way to tell if this is reachable by
423 * looking at the ancestry chain alone, so
424 * leave a note to ourselves not to worry about
425 * this object anymore.
426 */
427 want_obj.objects[i].item->flags |= COMMON_KNOWN;
428 continue;
429 }
430 if (!reachable((struct commit *)want))
431 return 0;
432 }
433 return 1;
434 }
435
436 static int get_common_commits(void)
437 {
438 static char line[1000];
439 unsigned char sha1[20];
440 char hex[41], last_hex[41];
441 int len;
442
443 track_object_refs = 0;
444 save_commit_buffer = 0;
445
446 for(;;) {
447 len = packet_read_line(0, line, sizeof(line));
448 reset_timeout();
449
450 if (!len) {
451 if (have_obj.nr == 0 || multi_ack)
452 packet_write(1, "NAK\n");
453 continue;
454 }
455 len = strip(line, len);
456 if (!prefixcmp(line, "have ")) {
457 switch (got_sha1(line+5, sha1)) {
458 case -1: /* they have what we do not */
459 if (multi_ack && ok_to_give_up())
460 packet_write(1, "ACK %s continue\n",
461 sha1_to_hex(sha1));
462 break;
463 default:
464 memcpy(hex, sha1_to_hex(sha1), 41);
465 if (multi_ack) {
466 const char *msg = "ACK %s continue\n";
467 packet_write(1, msg, hex);
468 memcpy(last_hex, hex, 41);
469 }
470 else if (have_obj.nr == 1)
471 packet_write(1, "ACK %s\n", hex);
472 break;
473 }
474 continue;
475 }
476 if (!strcmp(line, "done")) {
477 if (have_obj.nr > 0) {
478 if (multi_ack)
479 packet_write(1, "ACK %s\n", last_hex);
480 return 0;
481 }
482 packet_write(1, "NAK\n");
483 return -1;
484 }
485 die("git-upload-pack: expected SHA1 list, got '%s'", line);
486 }
487 }
488
489 static void receive_needs(void)
490 {
491 struct object_array shallows = {0, 0, NULL};
492 static char line[1000];
493 int len, depth = 0;
494
495 for (;;) {
496 struct object *o;
497 unsigned char sha1_buf[20];
498 len = packet_read_line(0, line, sizeof(line));
499 reset_timeout();
500 if (!len)
501 break;
502
503 if (!prefixcmp(line, "shallow ")) {
504 unsigned char sha1[20];
505 struct object *object;
506 use_thin_pack = 0;
507 if (get_sha1(line + 8, sha1))
508 die("invalid shallow line: %s", line);
509 object = parse_object(sha1);
510 if (!object)
511 die("did not find object for %s", line);
512 object->flags |= CLIENT_SHALLOW;
513 add_object_array(object, NULL, &shallows);
514 continue;
515 }
516 if (!prefixcmp(line, "deepen ")) {
517 char *end;
518 use_thin_pack = 0;
519 depth = strtol(line + 7, &end, 0);
520 if (end == line + 7 || depth <= 0)
521 die("Invalid deepen: %s", line);
522 continue;
523 }
524 if (prefixcmp(line, "want ") ||
525 get_sha1_hex(line+5, sha1_buf))
526 die("git-upload-pack: protocol error, "
527 "expected to get sha, not '%s'", line);
528 if (strstr(line+45, "multi_ack"))
529 multi_ack = 1;
530 if (strstr(line+45, "thin-pack"))
531 use_thin_pack = 1;
532 if (strstr(line+45, "ofs-delta"))
533 use_ofs_delta = 1;
534 if (strstr(line+45, "side-band-64k"))
535 use_sideband = LARGE_PACKET_MAX;
536 else if (strstr(line+45, "side-band"))
537 use_sideband = DEFAULT_PACKET_MAX;
538 if (strstr(line+45, "no-progress"))
539 no_progress = 1;
540
541 /* We have sent all our refs already, and the other end
542 * should have chosen out of them; otherwise they are
543 * asking for nonsense.
544 *
545 * Hmph. We may later want to allow "want" line that
546 * asks for something like "master~10" (symbolic)...
547 * would it make sense? I don't know.
548 */
549 o = lookup_object(sha1_buf);
550 if (!o || !(o->flags & OUR_REF))
551 die("git-upload-pack: not our ref %s", line+5);
552 if (!(o->flags & WANTED)) {
553 o->flags |= WANTED;
554 add_object_array(o, NULL, &want_obj);
555 }
556 }
557 if (depth == 0 && shallows.nr == 0)
558 return;
559 if (depth > 0) {
560 struct commit_list *result, *backup;
561 int i;
562 backup = result = get_shallow_commits(&want_obj, depth,
563 SHALLOW, NOT_SHALLOW);
564 while (result) {
565 struct object *object = &result->item->object;
566 if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
567 packet_write(1, "shallow %s",
568 sha1_to_hex(object->sha1));
569 register_shallow(object->sha1);
570 }
571 result = result->next;
572 }
573 free_commit_list(backup);
574 for (i = 0; i < shallows.nr; i++) {
575 struct object *object = shallows.objects[i].item;
576 if (object->flags & NOT_SHALLOW) {
577 struct commit_list *parents;
578 packet_write(1, "unshallow %s",
579 sha1_to_hex(object->sha1));
580 object->flags &= ~CLIENT_SHALLOW;
581 /* make sure the real parents are parsed */
582 unregister_shallow(object->sha1);
583 object->parsed = 0;
584 parse_commit((struct commit *)object);
585 parents = ((struct commit *)object)->parents;
586 while (parents) {
587 add_object_array(&parents->item->object,
588 NULL, &want_obj);
589 parents = parents->next;
590 }
591 }
592 /* make sure commit traversal conforms to client */
593 register_shallow(object->sha1);
594 }
595 packet_flush(1);
596 } else
597 if (shallows.nr > 0) {
598 int i;
599 for (i = 0; i < shallows.nr; i++)
600 register_shallow(shallows.objects[i].item->sha1);
601 }
602 free(shallows.objects);
603 }
604
605 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
606 {
607 static const char *capabilities = "multi_ack thin-pack side-band"
608 " side-band-64k ofs-delta shallow no-progress";
609 struct object *o = parse_object(sha1);
610
611 if (!o)
612 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
613
614 if (capabilities)
615 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
616 0, capabilities);
617 else
618 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
619 capabilities = NULL;
620 if (!(o->flags & OUR_REF)) {
621 o->flags |= OUR_REF;
622 nr_our_refs++;
623 }
624 if (o->type == OBJ_TAG) {
625 o = deref_tag(o, refname, 0);
626 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
627 }
628 return 0;
629 }
630
631 static void upload_pack(void)
632 {
633 reset_timeout();
634 head_ref(send_ref, NULL);
635 for_each_ref(send_ref, NULL);
636 packet_flush(1);
637 receive_needs();
638 if (want_obj.nr) {
639 get_common_commits();
640 create_pack_file();
641 }
642 }
643
644 int main(int argc, char **argv)
645 {
646 char *dir;
647 int i;
648 int strict = 0;
649
650 for (i = 1; i < argc; i++) {
651 char *arg = argv[i];
652
653 if (arg[0] != '-')
654 break;
655 if (!strcmp(arg, "--strict")) {
656 strict = 1;
657 continue;
658 }
659 if (!prefixcmp(arg, "--timeout=")) {
660 timeout = atoi(arg+10);
661 continue;
662 }
663 if (!strcmp(arg, "--")) {
664 i++;
665 break;
666 }
667 }
668
669 if (i != argc-1)
670 usage(upload_pack_usage);
671 dir = argv[i];
672
673 if (!enter_repo(dir, strict))
674 die("'%s': unable to chdir or not a git archive", dir);
675 if (is_repository_shallow())
676 die("attempt to fetch/clone from a shallow repository");
677 upload_pack();
678 return 0;
679 }