Merge branch 'tr/reset-checkout-patch'
[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, use_include_tag;
31 static int no_progress, daemon_mode;
32 static int shallow_nr;
33 static struct object_array have_obj;
34 static struct object_array want_obj;
35 static struct object_array extra_edge_obj;
36 static unsigned int timeout;
37 /* 0 for no sideband,
38  * otherwise maximum packet size (up to 65520 bytes).
39  */
40 static int use_sideband;
41 static int debug_fd;
42
43 static void reset_timeout(void)
44 {
45         alarm(timeout);
46 }
47
48 static int strip(char *line, int len)
49 {
50         if (len && line[len-1] == '\n')
51                 line[--len] = 0;
52         return len;
53 }
54
55 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
56 {
57         if (use_sideband)
58                 return send_sideband(1, fd, data, sz, use_sideband);
59         if (fd == 3)
60                 /* emergency quit */
61                 fd = 2;
62         if (fd == 2) {
63                 /* XXX: are we happy to lose stuff here? */
64                 xwrite(fd, data, sz);
65                 return sz;
66         }
67         return safe_write(fd, data, sz);
68 }
69
70 static FILE *pack_pipe = NULL;
71 static void show_commit(struct commit *commit, void *data)
72 {
73         if (commit->object.flags & BOUNDARY)
74                 fputc('-', pack_pipe);
75         if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
76                 die("broken output pipe");
77         fputc('\n', pack_pipe);
78         fflush(pack_pipe);
79         free(commit->buffer);
80         commit->buffer = NULL;
81 }
82
83 static void show_object(struct object *obj, const struct name_path *path, const char *component)
84 {
85         /* An object with name "foo\n0000000..." can be used to
86          * confuse downstream git-pack-objects very badly.
87          */
88         const char *name = path_name(path, component);
89         const char *ep = strchr(name, '\n');
90         if (ep) {
91                 fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(obj->sha1),
92                        (int) (ep - name),
93                        name);
94         }
95         else
96                 fprintf(pack_pipe, "%s %s\n",
97                                 sha1_to_hex(obj->sha1), name);
98         free((char *)name);
99 }
100
101 static void show_edge(struct commit *commit)
102 {
103         fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
104 }
105
106 static int do_rev_list(int fd, void *create_full_pack)
107 {
108         int i;
109         struct rev_info revs;
110
111         pack_pipe = fdopen(fd, "w");
112         init_revisions(&revs, NULL);
113         revs.tag_objects = 1;
114         revs.tree_objects = 1;
115         revs.blob_objects = 1;
116         if (use_thin_pack)
117                 revs.edge_hint = 1;
118
119         if (create_full_pack) {
120                 const char *args[] = {"rev-list", "--all", NULL};
121                 setup_revisions(2, args, &revs, NULL);
122         } else {
123                 for (i = 0; i < want_obj.nr; i++) {
124                         struct object *o = want_obj.objects[i].item;
125                         /* why??? */
126                         o->flags &= ~UNINTERESTING;
127                         add_pending_object(&revs, o, NULL);
128                 }
129                 for (i = 0; i < have_obj.nr; i++) {
130                         struct object *o = have_obj.objects[i].item;
131                         o->flags |= UNINTERESTING;
132                         add_pending_object(&revs, o, NULL);
133                 }
134                 setup_revisions(0, NULL, &revs, NULL);
135         }
136         if (prepare_revision_walk(&revs))
137                 die("revision walk setup failed");
138         mark_edges_uninteresting(revs.commits, &revs, show_edge);
139         if (use_thin_pack)
140                 for (i = 0; i < extra_edge_obj.nr; i++)
141                         fprintf(pack_pipe, "-%s\n", sha1_to_hex(
142                                         extra_edge_obj.objects[i].item->sha1));
143         traverse_commit_list(&revs, show_commit, show_object, NULL);
144         fflush(pack_pipe);
145         fclose(pack_pipe);
146         return 0;
147 }
148
149 static void create_pack_file(void)
150 {
151         struct async rev_list;
152         struct child_process pack_objects;
153         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
154         char data[8193], progress[128];
155         char abort_msg[] = "aborting due to possible repository "
156                 "corruption on the remote side.";
157         int buffered = -1;
158         ssize_t sz;
159         const char *argv[10];
160         int arg = 0;
161
162         if (shallow_nr) {
163                 rev_list.proc = do_rev_list;
164                 rev_list.data = 0;
165                 if (start_async(&rev_list))
166                         die("git upload-pack: unable to fork git-rev-list");
167                 argv[arg++] = "pack-objects";
168         } else {
169                 argv[arg++] = "pack-objects";
170                 argv[arg++] = "--revs";
171                 if (create_full_pack)
172                         argv[arg++] = "--all";
173                 else if (use_thin_pack)
174                         argv[arg++] = "--thin";
175         }
176
177         argv[arg++] = "--stdout";
178         if (!no_progress)
179                 argv[arg++] = "--progress";
180         if (use_ofs_delta)
181                 argv[arg++] = "--delta-base-offset";
182         if (use_include_tag)
183                 argv[arg++] = "--include-tag";
184         argv[arg++] = NULL;
185
186         memset(&pack_objects, 0, sizeof(pack_objects));
187         pack_objects.in = shallow_nr ? rev_list.out : -1;
188         pack_objects.out = -1;
189         pack_objects.err = -1;
190         pack_objects.git_cmd = 1;
191         pack_objects.argv = argv;
192
193         if (start_command(&pack_objects))
194                 die("git upload-pack: unable to fork git-pack-objects");
195
196         /* pass on revisions we (don't) want */
197         if (!shallow_nr) {
198                 FILE *pipe_fd = fdopen(pack_objects.in, "w");
199                 if (!create_full_pack) {
200                         int i;
201                         for (i = 0; i < want_obj.nr; i++)
202                                 fprintf(pipe_fd, "%s\n", sha1_to_hex(want_obj.objects[i].item->sha1));
203                         fprintf(pipe_fd, "--not\n");
204                         for (i = 0; i < have_obj.nr; i++)
205                                 fprintf(pipe_fd, "%s\n", sha1_to_hex(have_obj.objects[i].item->sha1));
206                 }
207
208                 fprintf(pipe_fd, "\n");
209                 fflush(pipe_fd);
210                 fclose(pipe_fd);
211         }
212
213
214         /* We read from pack_objects.err to capture stderr output for
215          * progress bar, and pack_objects.out to capture the pack data.
216          */
217
218         while (1) {
219                 struct pollfd pfd[2];
220                 int pe, pu, pollsize;
221
222                 reset_timeout();
223
224                 pollsize = 0;
225                 pe = pu = -1;
226
227                 if (0 <= pack_objects.out) {
228                         pfd[pollsize].fd = pack_objects.out;
229                         pfd[pollsize].events = POLLIN;
230                         pu = pollsize;
231                         pollsize++;
232                 }
233                 if (0 <= pack_objects.err) {
234                         pfd[pollsize].fd = pack_objects.err;
235                         pfd[pollsize].events = POLLIN;
236                         pe = pollsize;
237                         pollsize++;
238                 }
239
240                 if (!pollsize)
241                         break;
242
243                 if (poll(pfd, pollsize, -1) < 0) {
244                         if (errno != EINTR) {
245                                 error("poll failed, resuming: %s",
246                                       strerror(errno));
247                                 sleep(1);
248                         }
249                         continue;
250                 }
251                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
252                         /* Data ready; we keep the last byte to ourselves
253                          * in case we detect broken rev-list, so that we
254                          * can leave the stream corrupted.  This is
255                          * unfortunate -- unpack-objects would happily
256                          * accept a valid packdata with trailing garbage,
257                          * so appending garbage after we pass all the
258                          * pack data is not good enough to signal
259                          * breakage to downstream.
260                          */
261                         char *cp = data;
262                         ssize_t outsz = 0;
263                         if (0 <= buffered) {
264                                 *cp++ = buffered;
265                                 outsz++;
266                         }
267                         sz = xread(pack_objects.out, cp,
268                                   sizeof(data) - outsz);
269                         if (0 < sz)
270                                         ;
271                         else if (sz == 0) {
272                                 close(pack_objects.out);
273                                 pack_objects.out = -1;
274                         }
275                         else
276                                 goto fail;
277                         sz += outsz;
278                         if (1 < sz) {
279                                 buffered = data[sz-1] & 0xFF;
280                                 sz--;
281                         }
282                         else
283                                 buffered = -1;
284                         sz = send_client_data(1, data, sz);
285                         if (sz < 0)
286                                 goto fail;
287                 }
288                 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
289                         /* Status ready; we ship that in the side-band
290                          * or dump to the standard error.
291                          */
292                         sz = xread(pack_objects.err, progress,
293                                   sizeof(progress));
294                         if (0 < sz)
295                                 send_client_data(2, progress, sz);
296                         else if (sz == 0) {
297                                 close(pack_objects.err);
298                                 pack_objects.err = -1;
299                         }
300                         else
301                                 goto fail;
302                 }
303         }
304
305         if (finish_command(&pack_objects)) {
306                 error("git upload-pack: git-pack-objects died with error.");
307                 goto fail;
308         }
309         if (shallow_nr && finish_async(&rev_list))
310                 goto fail;      /* error was already reported */
311
312         /* flush the data */
313         if (0 <= buffered) {
314                 data[0] = buffered;
315                 sz = send_client_data(1, data, 1);
316                 if (sz < 0)
317                         goto fail;
318                 fprintf(stderr, "flushed.\n");
319         }
320         if (use_sideband)
321                 packet_flush(1);
322         return;
323
324  fail:
325         send_client_data(3, abort_msg, sizeof(abort_msg));
326         die("git upload-pack: %s", abort_msg);
327 }
328
329 static int got_sha1(char *hex, unsigned char *sha1)
330 {
331         struct object *o;
332         int we_knew_they_have = 0;
333
334         if (get_sha1_hex(hex, sha1))
335                 die("git upload-pack: expected SHA1 object, got '%s'", hex);
336         if (!has_sha1_file(sha1))
337                 return -1;
338
339         o = lookup_object(sha1);
340         if (!(o && o->parsed))
341                 o = parse_object(sha1);
342         if (!o)
343                 die("oops (%s)", sha1_to_hex(sha1));
344         if (o->type == OBJ_COMMIT) {
345                 struct commit_list *parents;
346                 struct commit *commit = (struct commit *)o;
347                 if (o->flags & THEY_HAVE)
348                         we_knew_they_have = 1;
349                 else
350                         o->flags |= THEY_HAVE;
351                 if (!oldest_have || (commit->date < oldest_have))
352                         oldest_have = commit->date;
353                 for (parents = commit->parents;
354                      parents;
355                      parents = parents->next)
356                         parents->item->object.flags |= THEY_HAVE;
357         }
358         if (!we_knew_they_have) {
359                 add_object_array(o, NULL, &have_obj);
360                 return 1;
361         }
362         return 0;
363 }
364
365 static int reachable(struct commit *want)
366 {
367         struct commit_list *work = NULL;
368
369         insert_by_date(want, &work);
370         while (work) {
371                 struct commit_list *list = work->next;
372                 struct commit *commit = work->item;
373                 free(work);
374                 work = list;
375
376                 if (commit->object.flags & THEY_HAVE) {
377                         want->object.flags |= COMMON_KNOWN;
378                         break;
379                 }
380                 if (!commit->object.parsed)
381                         parse_object(commit->object.sha1);
382                 if (commit->object.flags & REACHABLE)
383                         continue;
384                 commit->object.flags |= REACHABLE;
385                 if (commit->date < oldest_have)
386                         continue;
387                 for (list = commit->parents; list; list = list->next) {
388                         struct commit *parent = list->item;
389                         if (!(parent->object.flags & REACHABLE))
390                                 insert_by_date(parent, &work);
391                 }
392         }
393         want->object.flags |= REACHABLE;
394         clear_commit_marks(want, REACHABLE);
395         free_commit_list(work);
396         return (want->object.flags & COMMON_KNOWN);
397 }
398
399 static int ok_to_give_up(void)
400 {
401         int i;
402
403         if (!have_obj.nr)
404                 return 0;
405
406         for (i = 0; i < want_obj.nr; i++) {
407                 struct object *want = want_obj.objects[i].item;
408
409                 if (want->flags & COMMON_KNOWN)
410                         continue;
411                 want = deref_tag(want, "a want line", 0);
412                 if (!want || want->type != OBJ_COMMIT) {
413                         /* no way to tell if this is reachable by
414                          * looking at the ancestry chain alone, so
415                          * leave a note to ourselves not to worry about
416                          * this object anymore.
417                          */
418                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
419                         continue;
420                 }
421                 if (!reachable((struct commit *)want))
422                         return 0;
423         }
424         return 1;
425 }
426
427 static int get_common_commits(void)
428 {
429         static char line[1000];
430         unsigned char sha1[20];
431         char hex[41], last_hex[41];
432
433         save_commit_buffer = 0;
434
435         for (;;) {
436                 int len = packet_read_line(0, line, sizeof(line));
437                 reset_timeout();
438
439                 if (!len) {
440                         if (have_obj.nr == 0 || multi_ack)
441                                 packet_write(1, "NAK\n");
442                         continue;
443                 }
444                 strip(line, len);
445                 if (!prefixcmp(line, "have ")) {
446                         switch (got_sha1(line+5, sha1)) {
447                         case -1: /* they have what we do not */
448                                 if (multi_ack && ok_to_give_up())
449                                         packet_write(1, "ACK %s continue\n",
450                                                      sha1_to_hex(sha1));
451                                 break;
452                         default:
453                                 memcpy(hex, sha1_to_hex(sha1), 41);
454                                 if (multi_ack) {
455                                         const char *msg = "ACK %s continue\n";
456                                         packet_write(1, msg, hex);
457                                         memcpy(last_hex, hex, 41);
458                                 }
459                                 else if (have_obj.nr == 1)
460                                         packet_write(1, "ACK %s\n", hex);
461                                 break;
462                         }
463                         continue;
464                 }
465                 if (!strcmp(line, "done")) {
466                         if (have_obj.nr > 0) {
467                                 if (multi_ack)
468                                         packet_write(1, "ACK %s\n", last_hex);
469                                 return 0;
470                         }
471                         packet_write(1, "NAK\n");
472                         return -1;
473                 }
474                 die("git upload-pack: expected SHA1 list, got '%s'", line);
475         }
476 }
477
478 static void receive_needs(void)
479 {
480         struct object_array shallows = {0, 0, NULL};
481         static char line[1000];
482         int len, depth = 0;
483
484         shallow_nr = 0;
485         if (debug_fd)
486                 write_in_full(debug_fd, "#S\n", 3);
487         for (;;) {
488                 struct object *o;
489                 unsigned char sha1_buf[20];
490                 len = packet_read_line(0, line, sizeof(line));
491                 reset_timeout();
492                 if (!len)
493                         break;
494                 if (debug_fd)
495                         write_in_full(debug_fd, line, len);
496
497                 if (!prefixcmp(line, "shallow ")) {
498                         unsigned char sha1[20];
499                         struct object *object;
500                         if (get_sha1(line + 8, sha1))
501                                 die("invalid shallow line: %s", line);
502                         object = parse_object(sha1);
503                         if (!object)
504                                 die("did not find object for %s", line);
505                         object->flags |= CLIENT_SHALLOW;
506                         add_object_array(object, NULL, &shallows);
507                         continue;
508                 }
509                 if (!prefixcmp(line, "deepen ")) {
510                         char *end;
511                         depth = strtol(line + 7, &end, 0);
512                         if (end == line + 7 || depth <= 0)
513                                 die("Invalid deepen: %s", line);
514                         continue;
515                 }
516                 if (prefixcmp(line, "want ") ||
517                     get_sha1_hex(line+5, sha1_buf))
518                         die("git upload-pack: protocol error, "
519                             "expected to get sha, not '%s'", line);
520                 if (strstr(line+45, "multi_ack"))
521                         multi_ack = 1;
522                 if (strstr(line+45, "thin-pack"))
523                         use_thin_pack = 1;
524                 if (strstr(line+45, "ofs-delta"))
525                         use_ofs_delta = 1;
526                 if (strstr(line+45, "side-band-64k"))
527                         use_sideband = LARGE_PACKET_MAX;
528                 else if (strstr(line+45, "side-band"))
529                         use_sideband = DEFAULT_PACKET_MAX;
530                 if (strstr(line+45, "no-progress"))
531                         no_progress = 1;
532                 if (strstr(line+45, "include-tag"))
533                         use_include_tag = 1;
534
535                 /* We have sent all our refs already, and the other end
536                  * should have chosen out of them; otherwise they are
537                  * asking for nonsense.
538                  *
539                  * Hmph.  We may later want to allow "want" line that
540                  * asks for something like "master~10" (symbolic)...
541                  * would it make sense?  I don't know.
542                  */
543                 o = lookup_object(sha1_buf);
544                 if (!o || !(o->flags & OUR_REF))
545                         die("git upload-pack: not our ref %s", line+5);
546                 if (!(o->flags & WANTED)) {
547                         o->flags |= WANTED;
548                         add_object_array(o, NULL, &want_obj);
549                 }
550         }
551         if (debug_fd)
552                 write_in_full(debug_fd, "#E\n", 3);
553
554         if (!use_sideband && daemon_mode)
555                 no_progress = 1;
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                                 shallow_nr++;
571                         }
572                         result = result->next;
573                 }
574                 free_commit_list(backup);
575                 for (i = 0; i < shallows.nr; i++) {
576                         struct object *object = shallows.objects[i].item;
577                         if (object->flags & NOT_SHALLOW) {
578                                 struct commit_list *parents;
579                                 packet_write(1, "unshallow %s",
580                                         sha1_to_hex(object->sha1));
581                                 object->flags &= ~CLIENT_SHALLOW;
582                                 /* make sure the real parents are parsed */
583                                 unregister_shallow(object->sha1);
584                                 object->parsed = 0;
585                                 if (parse_commit((struct commit *)object))
586                                         die("invalid commit");
587                                 parents = ((struct commit *)object)->parents;
588                                 while (parents) {
589                                         add_object_array(&parents->item->object,
590                                                         NULL, &want_obj);
591                                         parents = parents->next;
592                                 }
593                                 add_object_array(object, NULL, &extra_edge_obj);
594                         }
595                         /* make sure commit traversal conforms to client */
596                         register_shallow(object->sha1);
597                 }
598                 packet_flush(1);
599         } else
600                 if (shallows.nr > 0) {
601                         int i;
602                         for (i = 0; i < shallows.nr; i++)
603                                 register_shallow(shallows.objects[i].item->sha1);
604                 }
605
606         shallow_nr += shallows.nr;
607         free(shallows.objects);
608 }
609
610 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
611 {
612         static const char *capabilities = "multi_ack thin-pack side-band"
613                 " side-band-64k ofs-delta shallow no-progress"
614                 " include-tag";
615         struct object *o = parse_object(sha1);
616
617         if (!o)
618                 die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
619
620         if (capabilities)
621                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
622                         0, capabilities);
623         else
624                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
625         capabilities = NULL;
626         if (!(o->flags & OUR_REF)) {
627                 o->flags |= OUR_REF;
628                 nr_our_refs++;
629         }
630         if (o->type == OBJ_TAG) {
631                 o = deref_tag(o, refname, 0);
632                 if (o)
633                         packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
634         }
635         return 0;
636 }
637
638 static void upload_pack(void)
639 {
640         reset_timeout();
641         head_ref(send_ref, NULL);
642         for_each_ref(send_ref, NULL);
643         packet_flush(1);
644         receive_needs();
645         if (want_obj.nr) {
646                 get_common_commits();
647                 create_pack_file();
648         }
649 }
650
651 int main(int argc, char **argv)
652 {
653         char *dir;
654         int i;
655         int strict = 0;
656
657         git_extract_argv0_path(argv[0]);
658         read_replace_refs = 0;
659
660         for (i = 1; i < argc; i++) {
661                 char *arg = argv[i];
662
663                 if (arg[0] != '-')
664                         break;
665                 if (!strcmp(arg, "--strict")) {
666                         strict = 1;
667                         continue;
668                 }
669                 if (!prefixcmp(arg, "--timeout=")) {
670                         timeout = atoi(arg+10);
671                         daemon_mode = 1;
672                         continue;
673                 }
674                 if (!strcmp(arg, "--")) {
675                         i++;
676                         break;
677                 }
678         }
679
680         if (i != argc-1)
681                 usage(upload_pack_usage);
682
683         setup_path();
684
685         dir = argv[i];
686
687         if (!enter_repo(dir, strict))
688                 die("'%s' does not appear to be a git repository", dir);
689         if (is_repository_shallow())
690                 die("attempt to fetch/clone from a shallow repository");
691         if (getenv("GIT_DEBUG_SEND_PACK"))
692                 debug_fd = atoi(getenv("GIT_DEBUG_SEND_PACK"));
693         upload_pack();
694         return 0;
695 }