Create pack_report() as a debugging aid.
[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
13 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
14
15 /* bits #0..7 in revision.h, #8..10 in commit.c */
16 #define THEY_HAVE       (1u << 11)
17 #define OUR_REF         (1u << 12)
18 #define WANTED          (1u << 13)
19 #define COMMON_KNOWN    (1u << 14)
20 #define REACHABLE       (1u << 15)
21
22 #define SHALLOW         (1u << 16)
23 #define NOT_SHALLOW     (1u << 17)
24 #define CLIENT_SHALLOW  (1u << 18)
25
26 static unsigned long oldest_have;
27
28 static int multi_ack, nr_our_refs;
29 static int use_thin_pack, use_ofs_delta;
30 static struct object_array have_obj;
31 static struct object_array want_obj;
32 static unsigned int timeout;
33 /* 0 for no sideband,
34  * otherwise maximum packet size (up to 65520 bytes).
35  */
36 static int use_sideband;
37
38 static void reset_timeout(void)
39 {
40         alarm(timeout);
41 }
42
43 static int strip(char *line, int len)
44 {
45         if (len && line[len-1] == '\n')
46                 line[--len] = 0;
47         return len;
48 }
49
50 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
51 {
52         if (use_sideband)
53                 return send_sideband(1, fd, data, sz, use_sideband);
54         if (fd == 3)
55                 /* emergency quit */
56                 fd = 2;
57         if (fd == 2) {
58                 xwrite(fd, data, sz);
59                 return sz;
60         }
61         return safe_write(fd, data, sz);
62 }
63
64 FILE *pack_pipe = NULL;
65 static void show_commit(struct commit *commit)
66 {
67         if (commit->object.flags & BOUNDARY)
68                 fputc('-', pack_pipe);
69         if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
70                 die("broken output pipe");
71         fputc('\n', pack_pipe);
72         fflush(pack_pipe);
73         free(commit->buffer);
74         commit->buffer = NULL;
75 }
76
77 static void show_object(struct object_array_entry *p)
78 {
79         /* An object with name "foo\n0000000..." can be used to
80          * confuse downstream git-pack-objects very badly.
81          */
82         const char *ep = strchr(p->name, '\n');
83         if (ep) {
84                 fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
85                        (int) (ep - p->name),
86                        p->name);
87         }
88         else
89                 fprintf(pack_pipe, "%s %s\n",
90                                 sha1_to_hex(p->item->sha1), p->name);
91 }
92
93 static void show_edge(struct commit *commit)
94 {
95         fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
96 }
97
98 static void create_pack_file(void)
99 {
100         /* Pipes between rev-list to pack-objects, pack-objects to us
101          * and pack-objects error stream for progress bar.
102          */
103         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
104         pid_t pid_rev_list, pid_pack_objects;
105         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
106         char data[8193], progress[128];
107         char abort_msg[] = "aborting due to possible repository "
108                 "corruption on the remote side.";
109         int buffered = -1;
110
111         if (pipe(lp_pipe) < 0)
112                 die("git-upload-pack: unable to create pipe");
113         pid_rev_list = fork();
114         if (pid_rev_list < 0)
115                 die("git-upload-pack: unable to fork git-rev-list");
116
117         if (!pid_rev_list) {
118                 int i;
119                 struct rev_info revs;
120
121                 pack_pipe = fdopen(lp_pipe[1], "w");
122
123                 if (create_full_pack)
124                         use_thin_pack = 0; /* no point doing it */
125                 init_revisions(&revs, NULL);
126                 revs.tag_objects = 1;
127                 revs.tree_objects = 1;
128                 revs.blob_objects = 1;
129                 if (use_thin_pack)
130                         revs.edge_hint = 1;
131
132                 if (create_full_pack) {
133                         const char *args[] = {"rev-list", "--all", NULL};
134                         setup_revisions(2, args, &revs, NULL);
135                 } else {
136                         for (i = 0; i < want_obj.nr; i++) {
137                                 struct object *o = want_obj.objects[i].item;
138                                 /* why??? */
139                                 o->flags &= ~UNINTERESTING;
140                                 add_pending_object(&revs, o, NULL);
141                         }
142                         for (i = 0; i < have_obj.nr; i++) {
143                                 struct object *o = have_obj.objects[i].item;
144                                 o->flags |= UNINTERESTING;
145                                 add_pending_object(&revs, o, NULL);
146                         }
147                         setup_revisions(0, NULL, &revs, NULL);
148                 }
149                 prepare_revision_walk(&revs);
150                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
151                 traverse_commit_list(&revs, show_commit, show_object);
152                 exit(0);
153         }
154
155         if (pipe(pu_pipe) < 0)
156                 die("git-upload-pack: unable to create pipe");
157         if (pipe(pe_pipe) < 0)
158                 die("git-upload-pack: unable to create pipe");
159         pid_pack_objects = fork();
160         if (pid_pack_objects < 0) {
161                 /* daemon sets things up to ignore TERM */
162                 kill(pid_rev_list, SIGKILL);
163                 die("git-upload-pack: unable to fork git-pack-objects");
164         }
165         if (!pid_pack_objects) {
166                 dup2(lp_pipe[0], 0);
167                 dup2(pu_pipe[1], 1);
168                 dup2(pe_pipe[1], 2);
169
170                 close(lp_pipe[0]);
171                 close(lp_pipe[1]);
172                 close(pu_pipe[0]);
173                 close(pu_pipe[1]);
174                 close(pe_pipe[0]);
175                 close(pe_pipe[1]);
176                 execl_git_cmd("pack-objects", "--stdout", "--progress",
177                               use_ofs_delta ? "--delta-base-offset" : NULL,
178                               NULL);
179                 kill(pid_rev_list, SIGKILL);
180                 die("git-upload-pack: unable to exec git-pack-objects");
181         }
182
183         close(lp_pipe[0]);
184         close(lp_pipe[1]);
185
186         /* We read from pe_pipe[0] to capture stderr output for
187          * progress bar, and pu_pipe[0] to capture the pack data.
188          */
189         close(pe_pipe[1]);
190         close(pu_pipe[1]);
191
192         while (1) {
193                 const char *who;
194                 struct pollfd pfd[2];
195                 pid_t pid;
196                 int status;
197                 ssize_t sz;
198                 int pe, pu, pollsize;
199
200                 reset_timeout();
201
202                 pollsize = 0;
203                 pe = pu = -1;
204
205                 if (0 <= pu_pipe[0]) {
206                         pfd[pollsize].fd = pu_pipe[0];
207                         pfd[pollsize].events = POLLIN;
208                         pu = pollsize;
209                         pollsize++;
210                 }
211                 if (0 <= pe_pipe[0]) {
212                         pfd[pollsize].fd = pe_pipe[0];
213                         pfd[pollsize].events = POLLIN;
214                         pe = pollsize;
215                         pollsize++;
216                 }
217
218                 if (pollsize) {
219                         if (poll(pfd, pollsize, -1) < 0) {
220                                 if (errno != EINTR) {
221                                         error("poll failed, resuming: %s",
222                                               strerror(errno));
223                                         sleep(1);
224                                 }
225                                 continue;
226                         }
227                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
228                                 /* Data ready; we keep the last byte
229                                  * to ourselves in case we detect
230                                  * broken rev-list, so that we can
231                                  * leave the stream corrupted.  This
232                                  * is unfortunate -- unpack-objects
233                                  * would happily accept a valid pack
234                                  * data with trailing garbage, so
235                                  * appending garbage after we pass all
236                                  * the pack data is not good enough to
237                                  * signal breakage to downstream.
238                                  */
239                                 char *cp = data;
240                                 ssize_t outsz = 0;
241                                 if (0 <= buffered) {
242                                         *cp++ = buffered;
243                                         outsz++;
244                                 }
245                                 sz = read(pu_pipe[0], cp,
246                                           sizeof(data) - outsz);
247                                 if (0 < sz)
248                                                 ;
249                                 else if (sz == 0) {
250                                         close(pu_pipe[0]);
251                                         pu_pipe[0] = -1;
252                                 }
253                                 else
254                                         goto fail;
255                                 sz += outsz;
256                                 if (1 < sz) {
257                                         buffered = data[sz-1] & 0xFF;
258                                         sz--;
259                                 }
260                                 else
261                                         buffered = -1;
262                                 sz = send_client_data(1, data, sz);
263                                 if (sz < 0)
264                                         goto fail;
265                         }
266                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
267                                 /* Status ready; we ship that in the side-band
268                                  * or dump to the standard error.
269                                  */
270                                 sz = read(pe_pipe[0], progress,
271                                           sizeof(progress));
272                                 if (0 < sz)
273                                         send_client_data(2, progress, sz);
274                                 else if (sz == 0) {
275                                         close(pe_pipe[0]);
276                                         pe_pipe[0] = -1;
277                                 }
278                                 else
279                                         goto fail;
280                         }
281                 }
282
283                 /* See if the children are still there */
284                 if (pid_rev_list || pid_pack_objects) {
285                         pid = waitpid(-1, &status, WNOHANG);
286                         if (!pid)
287                                 continue;
288                         who = ((pid == pid_rev_list) ? "git-rev-list" :
289                                (pid == pid_pack_objects) ? "git-pack-objects" :
290                                NULL);
291                         if (!who) {
292                                 if (pid < 0) {
293                                         error("git-upload-pack: %s",
294                                               strerror(errno));
295                                         goto fail;
296                                 }
297                                 error("git-upload-pack: we weren't "
298                                       "waiting for %d", pid);
299                                 continue;
300                         }
301                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
302                                 error("git-upload-pack: %s died with error.",
303                                       who);
304                                 goto fail;
305                         }
306                         if (pid == pid_rev_list)
307                                 pid_rev_list = 0;
308                         if (pid == pid_pack_objects)
309                                 pid_pack_objects = 0;
310                         if (pid_rev_list || pid_pack_objects)
311                                 continue;
312                 }
313
314                 /* both died happily */
315                 if (pollsize)
316                         continue;
317
318                 /* flush the data */
319                 if (0 <= buffered) {
320                         data[0] = buffered;
321                         sz = send_client_data(1, data, 1);
322                         if (sz < 0)
323                                 goto fail;
324                         fprintf(stderr, "flushed.\n");
325                 }
326                 if (use_sideband)
327                         packet_flush(1);
328                 return;
329         }
330  fail:
331         if (pid_pack_objects)
332                 kill(pid_pack_objects, SIGKILL);
333         if (pid_rev_list)
334                 kill(pid_rev_list, SIGKILL);
335         send_client_data(3, abort_msg, sizeof(abort_msg));
336         die("git-upload-pack: %s", abort_msg);
337 }
338
339 static int got_sha1(char *hex, unsigned char *sha1)
340 {
341         struct object *o;
342         int we_knew_they_have = 0;
343
344         if (get_sha1_hex(hex, sha1))
345                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
346         if (!has_sha1_file(sha1))
347                 return -1;
348
349         o = lookup_object(sha1);
350         if (!(o && o->parsed))
351                 o = parse_object(sha1);
352         if (!o)
353                 die("oops (%s)", sha1_to_hex(sha1));
354         if (o->type == OBJ_COMMIT) {
355                 struct commit_list *parents;
356                 struct commit *commit = (struct commit *)o;
357                 if (o->flags & THEY_HAVE)
358                         we_knew_they_have = 1;
359                 else
360                         o->flags |= THEY_HAVE;
361                 if (!oldest_have || (commit->date < oldest_have))
362                         oldest_have = commit->date;
363                 for (parents = commit->parents;
364                      parents;
365                      parents = parents->next)
366                         parents->item->object.flags |= THEY_HAVE;
367         }
368         if (!we_knew_they_have) {
369                 add_object_array(o, NULL, &have_obj);
370                 return 1;
371         }
372         return 0;
373 }
374
375 static int reachable(struct commit *want)
376 {
377         struct commit_list *work = NULL;
378
379         insert_by_date(want, &work);
380         while (work) {
381                 struct commit_list *list = work->next;
382                 struct commit *commit = work->item;
383                 free(work);
384                 work = list;
385
386                 if (commit->object.flags & THEY_HAVE) {
387                         want->object.flags |= COMMON_KNOWN;
388                         break;
389                 }
390                 if (!commit->object.parsed)
391                         parse_object(commit->object.sha1);
392                 if (commit->object.flags & REACHABLE)
393                         continue;
394                 commit->object.flags |= REACHABLE;
395                 if (commit->date < oldest_have)
396                         continue;
397                 for (list = commit->parents; list; list = list->next) {
398                         struct commit *parent = list->item;
399                         if (!(parent->object.flags & REACHABLE))
400                                 insert_by_date(parent, &work);
401                 }
402         }
403         want->object.flags |= REACHABLE;
404         clear_commit_marks(want, REACHABLE);
405         free_commit_list(work);
406         return (want->object.flags & COMMON_KNOWN);
407 }
408
409 static int ok_to_give_up(void)
410 {
411         int i;
412
413         if (!have_obj.nr)
414                 return 0;
415
416         for (i = 0; i < want_obj.nr; i++) {
417                 struct object *want = want_obj.objects[i].item;
418
419                 if (want->flags & COMMON_KNOWN)
420                         continue;
421                 want = deref_tag(want, "a want line", 0);
422                 if (!want || want->type != OBJ_COMMIT) {
423                         /* no way to tell if this is reachable by
424                          * looking at the ancestry chain alone, so
425                          * leave a note to ourselves not to worry about
426                          * this object anymore.
427                          */
428                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
429                         continue;
430                 }
431                 if (!reachable((struct commit *)want))
432                         return 0;
433         }
434         return 1;
435 }
436
437 static int get_common_commits(void)
438 {
439         static char line[1000];
440         unsigned char sha1[20];
441         char hex[41], last_hex[41];
442         int len;
443
444         track_object_refs = 0;
445         save_commit_buffer = 0;
446
447         for(;;) {
448                 len = packet_read_line(0, line, sizeof(line));
449                 reset_timeout();
450
451                 if (!len) {
452                         if (have_obj.nr == 0 || multi_ack)
453                                 packet_write(1, "NAK\n");
454                         continue;
455                 }
456                 len = strip(line, len);
457                 if (!strncmp(line, "have ", 5)) {
458                         switch (got_sha1(line+5, sha1)) {
459                         case -1: /* they have what we do not */
460                                 if (multi_ack && ok_to_give_up())
461                                         packet_write(1, "ACK %s continue\n",
462                                                      sha1_to_hex(sha1));
463                                 break;
464                         default:
465                                 memcpy(hex, sha1_to_hex(sha1), 41);
466                                 if (multi_ack) {
467                                         const char *msg = "ACK %s continue\n";
468                                         packet_write(1, msg, hex);
469                                         memcpy(last_hex, hex, 41);
470                                 }
471                                 else if (have_obj.nr == 1)
472                                         packet_write(1, "ACK %s\n", hex);
473                                 break;
474                         }
475                         continue;
476                 }
477                 if (!strcmp(line, "done")) {
478                         if (have_obj.nr > 0) {
479                                 if (multi_ack)
480                                         packet_write(1, "ACK %s\n", last_hex);
481                                 return 0;
482                         }
483                         packet_write(1, "NAK\n");
484                         return -1;
485                 }
486                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
487         }
488 }
489
490 static void receive_needs(void)
491 {
492         struct object_array shallows = {0, 0, NULL};
493         static char line[1000];
494         int len, depth = 0;
495
496         for (;;) {
497                 struct object *o;
498                 unsigned char sha1_buf[20];
499                 len = packet_read_line(0, line, sizeof(line));
500                 reset_timeout();
501                 if (!len)
502                         break;
503
504                 if (!strncmp("shallow ", line, 8)) {
505                         unsigned char sha1[20];
506                         struct object *object;
507                         use_thin_pack = 0;
508                         if (get_sha1(line + 8, sha1))
509                                 die("invalid shallow line: %s", line);
510                         object = parse_object(sha1);
511                         if (!object)
512                                 die("did not find object for %s", line);
513                         object->flags |= CLIENT_SHALLOW;
514                         add_object_array(object, NULL, &shallows);
515                         continue;
516                 }
517                 if (!strncmp("deepen ", line, 7)) {
518                         char *end;
519                         use_thin_pack = 0;
520                         depth = strtol(line + 7, &end, 0);
521                         if (end == line + 7 || depth <= 0)
522                                 die("Invalid deepen: %s", line);
523                         continue;
524                 }
525                 if (strncmp("want ", line, 5) ||
526                     get_sha1_hex(line+5, sha1_buf))
527                         die("git-upload-pack: protocol error, "
528                             "expected to get sha, not '%s'", line);
529                 if (strstr(line+45, "multi_ack"))
530                         multi_ack = 1;
531                 if (strstr(line+45, "thin-pack"))
532                         use_thin_pack = 1;
533                 if (strstr(line+45, "ofs-delta"))
534                         use_ofs_delta = 1;
535                 if (strstr(line+45, "side-band-64k"))
536                         use_sideband = LARGE_PACKET_MAX;
537                 else if (strstr(line+45, "side-band"))
538                         use_sideband = DEFAULT_PACKET_MAX;
539
540                 /* We have sent all our refs already, and the other end
541                  * should have chosen out of them; otherwise they are
542                  * asking for nonsense.
543                  *
544                  * Hmph.  We may later want to allow "want" line that
545                  * asks for something like "master~10" (symbolic)...
546                  * would it make sense?  I don't know.
547                  */
548                 o = lookup_object(sha1_buf);
549                 if (!o || !(o->flags & OUR_REF))
550                         die("git-upload-pack: not our ref %s", line+5);
551                 if (!(o->flags & WANTED)) {
552                         o->flags |= WANTED;
553                         add_object_array(o, NULL, &want_obj);
554                 }
555         }
556         if (depth == 0 && shallows.nr == 0)
557                 return;
558         if (depth > 0) {
559                 struct commit_list *result, *backup;
560                 int i;
561                 backup = result = get_shallow_commits(&want_obj, depth,
562                         SHALLOW, NOT_SHALLOW);
563                 while (result) {
564                         struct object *object = &result->item->object;
565                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
566                                 packet_write(1, "shallow %s",
567                                                 sha1_to_hex(object->sha1));
568                                 register_shallow(object->sha1);
569                         }
570                         result = result->next;
571                 }
572                 free_commit_list(backup);
573                 for (i = 0; i < shallows.nr; i++) {
574                         struct object *object = shallows.objects[i].item;
575                         if (object->flags & NOT_SHALLOW) {
576                                 struct commit_list *parents;
577                                 packet_write(1, "unshallow %s",
578                                         sha1_to_hex(object->sha1));
579                                 object->flags &= ~CLIENT_SHALLOW;
580                                 /* make sure the real parents are parsed */
581                                 unregister_shallow(object->sha1);
582                                 object->parsed = 0;
583                                 parse_commit((struct commit *)object);
584                                 parents = ((struct commit *)object)->parents;
585                                 while (parents) {
586                                         add_object_array(&parents->item->object,
587                                                         NULL, &want_obj);
588                                         parents = parents->next;
589                                 }
590                         }
591                         /* make sure commit traversal conforms to client */
592                         register_shallow(object->sha1);
593                 }
594                 packet_flush(1);
595         } else
596                 if (shallows.nr > 0) {
597                         int i;
598                         for (i = 0; i < shallows.nr; i++)
599                                 register_shallow(shallows.objects[i].item->sha1);
600                 }
601         free(shallows.objects);
602 }
603
604 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
605 {
606         static const char *capabilities = "multi_ack thin-pack side-band"
607                 " side-band-64k ofs-delta shallow";
608         struct object *o = parse_object(sha1);
609
610         if (!o)
611                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
612
613         if (capabilities)
614                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
615                         0, capabilities);
616         else
617                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
618         capabilities = NULL;
619         if (!(o->flags & OUR_REF)) {
620                 o->flags |= OUR_REF;
621                 nr_our_refs++;
622         }
623         if (o->type == OBJ_TAG) {
624                 o = deref_tag(o, refname, 0);
625                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
626         }
627         return 0;
628 }
629
630 static void upload_pack(void)
631 {
632         reset_timeout();
633         head_ref(send_ref, NULL);
634         for_each_ref(send_ref, NULL);
635         packet_flush(1);
636         receive_needs();
637         if (want_obj.nr) {
638                 get_common_commits();
639                 create_pack_file();
640         }
641 }
642
643 int main(int argc, char **argv)
644 {
645         char *dir;
646         int i;
647         int strict = 0;
648
649         for (i = 1; i < argc; i++) {
650                 char *arg = argv[i];
651
652                 if (arg[0] != '-')
653                         break;
654                 if (!strcmp(arg, "--strict")) {
655                         strict = 1;
656                         continue;
657                 }
658                 if (!strncmp(arg, "--timeout=", 10)) {
659                         timeout = atoi(arg+10);
660                         continue;
661                 }
662                 if (!strcmp(arg, "--")) {
663                         i++;
664                         break;
665                 }
666         }
667         
668         if (i != argc-1)
669                 usage(upload_pack_usage);
670         dir = argv[i];
671
672         if (!enter_repo(dir, strict))
673                 die("'%s': unable to chdir or not a git archive", dir);
674
675         upload_pack();
676         return 0;
677 }