Merge branch 'sp/describe'
[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 int do_rev_list(int fd, void *create_full_pack)
101 {
102         int i;
103         struct rev_info revs;
104
105         pack_pipe = fdopen(fd, "w");
106         if (create_full_pack)
107                 use_thin_pack = 0; /* no point doing it */
108         init_revisions(&revs, NULL);
109         revs.tag_objects = 1;
110         revs.tree_objects = 1;
111         revs.blob_objects = 1;
112         if (use_thin_pack)
113                 revs.edge_hint = 1;
114
115         if (create_full_pack) {
116                 const char *args[] = {"rev-list", "--all", NULL};
117                 setup_revisions(2, args, &revs, NULL);
118         } else {
119                 for (i = 0; i < want_obj.nr; i++) {
120                         struct object *o = want_obj.objects[i].item;
121                         /* why??? */
122                         o->flags &= ~UNINTERESTING;
123                         add_pending_object(&revs, o, NULL);
124                 }
125                 for (i = 0; i < have_obj.nr; i++) {
126                         struct object *o = have_obj.objects[i].item;
127                         o->flags |= UNINTERESTING;
128                         add_pending_object(&revs, o, NULL);
129                 }
130                 setup_revisions(0, NULL, &revs, NULL);
131         }
132         if (prepare_revision_walk(&revs))
133                 die("revision walk setup failed");
134         mark_edges_uninteresting(revs.commits, &revs, show_edge);
135         traverse_commit_list(&revs, show_commit, show_object);
136         return 0;
137 }
138
139 static void create_pack_file(void)
140 {
141         struct async 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         ssize_t sz;
149         const char *argv[10];
150         int arg = 0;
151
152         rev_list.proc = do_rev_list;
153         /* .data is just a boolean: any non-NULL value will do */
154         rev_list.data = create_full_pack ? &rev_list : NULL;
155         if (start_async(&rev_list))
156                 die("git-upload-pack: unable to fork git-rev-list");
157
158         argv[arg++] = "pack-objects";
159         argv[arg++] = "--stdout";
160         if (!no_progress)
161                 argv[arg++] = "--progress";
162         if (use_ofs_delta)
163                 argv[arg++] = "--delta-base-offset";
164         argv[arg++] = NULL;
165
166         memset(&pack_objects, 0, sizeof(pack_objects));
167         pack_objects.in = rev_list.out; /* start_command closes it */
168         pack_objects.out = -1;
169         pack_objects.err = -1;
170         pack_objects.git_cmd = 1;
171         pack_objects.argv = argv;
172
173         if (start_command(&pack_objects))
174                 die("git-upload-pack: unable to fork git-pack-objects");
175
176         /* We read from pack_objects.err to capture stderr output for
177          * progress bar, and pack_objects.out to capture the pack data.
178          */
179
180         while (1) {
181                 struct pollfd pfd[2];
182                 int pe, pu, pollsize;
183
184                 reset_timeout();
185
186                 pollsize = 0;
187                 pe = pu = -1;
188
189                 if (0 <= pack_objects.out) {
190                         pfd[pollsize].fd = pack_objects.out;
191                         pfd[pollsize].events = POLLIN;
192                         pu = pollsize;
193                         pollsize++;
194                 }
195                 if (0 <= pack_objects.err) {
196                         pfd[pollsize].fd = pack_objects.err;
197                         pfd[pollsize].events = POLLIN;
198                         pe = pollsize;
199                         pollsize++;
200                 }
201
202                 if (!pollsize)
203                         break;
204
205                 if (poll(pfd, pollsize, -1) < 0) {
206                         if (errno != EINTR) {
207                                 error("poll failed, resuming: %s",
208                                       strerror(errno));
209                                 sleep(1);
210                         }
211                         continue;
212                 }
213                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
214                         /* Data ready; we keep the last byte to ourselves
215                          * in case we detect broken rev-list, so that we
216                          * can leave the stream corrupted.  This is
217                          * unfortunate -- unpack-objects would happily
218                          * accept a valid packdata with trailing garbage,
219                          * so appending garbage after we pass all the
220                          * pack data is not good enough to signal
221                          * breakage to downstream.
222                          */
223                         char *cp = data;
224                         ssize_t outsz = 0;
225                         if (0 <= buffered) {
226                                 *cp++ = buffered;
227                                 outsz++;
228                         }
229                         sz = xread(pack_objects.out, cp,
230                                   sizeof(data) - outsz);
231                         if (0 < sz)
232                                         ;
233                         else if (sz == 0) {
234                                 close(pack_objects.out);
235                                 pack_objects.out = -1;
236                         }
237                         else
238                                 goto fail;
239                         sz += outsz;
240                         if (1 < sz) {
241                                 buffered = data[sz-1] & 0xFF;
242                                 sz--;
243                         }
244                         else
245                                 buffered = -1;
246                         sz = send_client_data(1, data, sz);
247                         if (sz < 0)
248                                 goto fail;
249                 }
250                 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
251                         /* Status ready; we ship that in the side-band
252                          * or dump to the standard error.
253                          */
254                         sz = xread(pack_objects.err, progress,
255                                   sizeof(progress));
256                         if (0 < sz)
257                                 send_client_data(2, progress, sz);
258                         else if (sz == 0) {
259                                 close(pack_objects.err);
260                                 pack_objects.err = -1;
261                         }
262                         else
263                                 goto fail;
264                 }
265         }
266
267         if (finish_command(&pack_objects)) {
268                 error("git-upload-pack: git-pack-objects died with error.");
269                 goto fail;
270         }
271         if (finish_async(&rev_list))
272                 goto fail;      /* error was already reported */
273
274         /* flush the data */
275         if (0 <= buffered) {
276                 data[0] = buffered;
277                 sz = send_client_data(1, data, 1);
278                 if (sz < 0)
279                         goto fail;
280                 fprintf(stderr, "flushed.\n");
281         }
282         if (use_sideband)
283                 packet_flush(1);
284         return;
285
286  fail:
287         send_client_data(3, abort_msg, sizeof(abort_msg));
288         die("git-upload-pack: %s", abort_msg);
289 }
290
291 static int got_sha1(char *hex, unsigned char *sha1)
292 {
293         struct object *o;
294         int we_knew_they_have = 0;
295
296         if (get_sha1_hex(hex, sha1))
297                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
298         if (!has_sha1_file(sha1))
299                 return -1;
300
301         o = lookup_object(sha1);
302         if (!(o && o->parsed))
303                 o = parse_object(sha1);
304         if (!o)
305                 die("oops (%s)", sha1_to_hex(sha1));
306         if (o->type == OBJ_COMMIT) {
307                 struct commit_list *parents;
308                 struct commit *commit = (struct commit *)o;
309                 if (o->flags & THEY_HAVE)
310                         we_knew_they_have = 1;
311                 else
312                         o->flags |= THEY_HAVE;
313                 if (!oldest_have || (commit->date < oldest_have))
314                         oldest_have = commit->date;
315                 for (parents = commit->parents;
316                      parents;
317                      parents = parents->next)
318                         parents->item->object.flags |= THEY_HAVE;
319         }
320         if (!we_knew_they_have) {
321                 add_object_array(o, NULL, &have_obj);
322                 return 1;
323         }
324         return 0;
325 }
326
327 static int reachable(struct commit *want)
328 {
329         struct commit_list *work = NULL;
330
331         insert_by_date(want, &work);
332         while (work) {
333                 struct commit_list *list = work->next;
334                 struct commit *commit = work->item;
335                 free(work);
336                 work = list;
337
338                 if (commit->object.flags & THEY_HAVE) {
339                         want->object.flags |= COMMON_KNOWN;
340                         break;
341                 }
342                 if (!commit->object.parsed)
343                         parse_object(commit->object.sha1);
344                 if (commit->object.flags & REACHABLE)
345                         continue;
346                 commit->object.flags |= REACHABLE;
347                 if (commit->date < oldest_have)
348                         continue;
349                 for (list = commit->parents; list; list = list->next) {
350                         struct commit *parent = list->item;
351                         if (!(parent->object.flags & REACHABLE))
352                                 insert_by_date(parent, &work);
353                 }
354         }
355         want->object.flags |= REACHABLE;
356         clear_commit_marks(want, REACHABLE);
357         free_commit_list(work);
358         return (want->object.flags & COMMON_KNOWN);
359 }
360
361 static int ok_to_give_up(void)
362 {
363         int i;
364
365         if (!have_obj.nr)
366                 return 0;
367
368         for (i = 0; i < want_obj.nr; i++) {
369                 struct object *want = want_obj.objects[i].item;
370
371                 if (want->flags & COMMON_KNOWN)
372                         continue;
373                 want = deref_tag(want, "a want line", 0);
374                 if (!want || want->type != OBJ_COMMIT) {
375                         /* no way to tell if this is reachable by
376                          * looking at the ancestry chain alone, so
377                          * leave a note to ourselves not to worry about
378                          * this object anymore.
379                          */
380                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
381                         continue;
382                 }
383                 if (!reachable((struct commit *)want))
384                         return 0;
385         }
386         return 1;
387 }
388
389 static int get_common_commits(void)
390 {
391         static char line[1000];
392         unsigned char sha1[20];
393         char hex[41], last_hex[41];
394         int len;
395
396         track_object_refs = 0;
397         save_commit_buffer = 0;
398
399         for(;;) {
400                 len = packet_read_line(0, line, sizeof(line));
401                 reset_timeout();
402
403                 if (!len) {
404                         if (have_obj.nr == 0 || multi_ack)
405                                 packet_write(1, "NAK\n");
406                         continue;
407                 }
408                 len = strip(line, len);
409                 if (!prefixcmp(line, "have ")) {
410                         switch (got_sha1(line+5, sha1)) {
411                         case -1: /* they have what we do not */
412                                 if (multi_ack && ok_to_give_up())
413                                         packet_write(1, "ACK %s continue\n",
414                                                      sha1_to_hex(sha1));
415                                 break;
416                         default:
417                                 memcpy(hex, sha1_to_hex(sha1), 41);
418                                 if (multi_ack) {
419                                         const char *msg = "ACK %s continue\n";
420                                         packet_write(1, msg, hex);
421                                         memcpy(last_hex, hex, 41);
422                                 }
423                                 else if (have_obj.nr == 1)
424                                         packet_write(1, "ACK %s\n", hex);
425                                 break;
426                         }
427                         continue;
428                 }
429                 if (!strcmp(line, "done")) {
430                         if (have_obj.nr > 0) {
431                                 if (multi_ack)
432                                         packet_write(1, "ACK %s\n", last_hex);
433                                 return 0;
434                         }
435                         packet_write(1, "NAK\n");
436                         return -1;
437                 }
438                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
439         }
440 }
441
442 static void receive_needs(void)
443 {
444         struct object_array shallows = {0, 0, NULL};
445         static char line[1000];
446         int len, depth = 0;
447
448         for (;;) {
449                 struct object *o;
450                 unsigned char sha1_buf[20];
451                 len = packet_read_line(0, line, sizeof(line));
452                 reset_timeout();
453                 if (!len)
454                         break;
455
456                 if (!prefixcmp(line, "shallow ")) {
457                         unsigned char sha1[20];
458                         struct object *object;
459                         use_thin_pack = 0;
460                         if (get_sha1(line + 8, sha1))
461                                 die("invalid shallow line: %s", line);
462                         object = parse_object(sha1);
463                         if (!object)
464                                 die("did not find object for %s", line);
465                         object->flags |= CLIENT_SHALLOW;
466                         add_object_array(object, NULL, &shallows);
467                         continue;
468                 }
469                 if (!prefixcmp(line, "deepen ")) {
470                         char *end;
471                         use_thin_pack = 0;
472                         depth = strtol(line + 7, &end, 0);
473                         if (end == line + 7 || depth <= 0)
474                                 die("Invalid deepen: %s", line);
475                         continue;
476                 }
477                 if (prefixcmp(line, "want ") ||
478                     get_sha1_hex(line+5, sha1_buf))
479                         die("git-upload-pack: protocol error, "
480                             "expected to get sha, not '%s'", line);
481                 if (strstr(line+45, "multi_ack"))
482                         multi_ack = 1;
483                 if (strstr(line+45, "thin-pack"))
484                         use_thin_pack = 1;
485                 if (strstr(line+45, "ofs-delta"))
486                         use_ofs_delta = 1;
487                 if (strstr(line+45, "side-band-64k"))
488                         use_sideband = LARGE_PACKET_MAX;
489                 else if (strstr(line+45, "side-band"))
490                         use_sideband = DEFAULT_PACKET_MAX;
491                 if (strstr(line+45, "no-progress"))
492                         no_progress = 1;
493
494                 /* We have sent all our refs already, and the other end
495                  * should have chosen out of them; otherwise they are
496                  * asking for nonsense.
497                  *
498                  * Hmph.  We may later want to allow "want" line that
499                  * asks for something like "master~10" (symbolic)...
500                  * would it make sense?  I don't know.
501                  */
502                 o = lookup_object(sha1_buf);
503                 if (!o || !(o->flags & OUR_REF))
504                         die("git-upload-pack: not our ref %s", line+5);
505                 if (!(o->flags & WANTED)) {
506                         o->flags |= WANTED;
507                         add_object_array(o, NULL, &want_obj);
508                 }
509         }
510         if (depth == 0 && shallows.nr == 0)
511                 return;
512         if (depth > 0) {
513                 struct commit_list *result, *backup;
514                 int i;
515                 backup = result = get_shallow_commits(&want_obj, depth,
516                         SHALLOW, NOT_SHALLOW);
517                 while (result) {
518                         struct object *object = &result->item->object;
519                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
520                                 packet_write(1, "shallow %s",
521                                                 sha1_to_hex(object->sha1));
522                                 register_shallow(object->sha1);
523                         }
524                         result = result->next;
525                 }
526                 free_commit_list(backup);
527                 for (i = 0; i < shallows.nr; i++) {
528                         struct object *object = shallows.objects[i].item;
529                         if (object->flags & NOT_SHALLOW) {
530                                 struct commit_list *parents;
531                                 packet_write(1, "unshallow %s",
532                                         sha1_to_hex(object->sha1));
533                                 object->flags &= ~CLIENT_SHALLOW;
534                                 /* make sure the real parents are parsed */
535                                 unregister_shallow(object->sha1);
536                                 object->parsed = 0;
537                                 if (parse_commit((struct commit *)object))
538                                         die("invalid commit");
539                                 parents = ((struct commit *)object)->parents;
540                                 while (parents) {
541                                         add_object_array(&parents->item->object,
542                                                         NULL, &want_obj);
543                                         parents = parents->next;
544                                 }
545                         }
546                         /* make sure commit traversal conforms to client */
547                         register_shallow(object->sha1);
548                 }
549                 packet_flush(1);
550         } else
551                 if (shallows.nr > 0) {
552                         int i;
553                         for (i = 0; i < shallows.nr; i++)
554                                 register_shallow(shallows.objects[i].item->sha1);
555                 }
556         free(shallows.objects);
557 }
558
559 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
560 {
561         static const char *capabilities = "multi_ack thin-pack side-band"
562                 " side-band-64k ofs-delta shallow no-progress";
563         struct object *o = parse_object(sha1);
564
565         if (!o)
566                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
567
568         if (capabilities)
569                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
570                         0, capabilities);
571         else
572                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
573         capabilities = NULL;
574         if (!(o->flags & OUR_REF)) {
575                 o->flags |= OUR_REF;
576                 nr_our_refs++;
577         }
578         if (o->type == OBJ_TAG) {
579                 o = deref_tag(o, refname, 0);
580                 if (o)
581                         packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
582         }
583         return 0;
584 }
585
586 static void upload_pack(void)
587 {
588         reset_timeout();
589         head_ref(send_ref, NULL);
590         for_each_ref(send_ref, NULL);
591         packet_flush(1);
592         receive_needs();
593         if (want_obj.nr) {
594                 get_common_commits();
595                 create_pack_file();
596         }
597 }
598
599 int main(int argc, char **argv)
600 {
601         char *dir;
602         int i;
603         int strict = 0;
604
605         for (i = 1; i < argc; i++) {
606                 char *arg = argv[i];
607
608                 if (arg[0] != '-')
609                         break;
610                 if (!strcmp(arg, "--strict")) {
611                         strict = 1;
612                         continue;
613                 }
614                 if (!prefixcmp(arg, "--timeout=")) {
615                         timeout = atoi(arg+10);
616                         continue;
617                 }
618                 if (!strcmp(arg, "--")) {
619                         i++;
620                         break;
621                 }
622         }
623
624         if (i != argc-1)
625                 usage(upload_pack_usage);
626
627         setup_path(NULL);
628
629         dir = argv[i];
630
631         if (!enter_repo(dir, strict))
632                 die("'%s': unable to chdir or not a git archive", dir);
633         if (is_repository_shallow())
634                 die("attempt to fetch/clone from a shallow repository");
635         upload_pack();
636         return 0;
637 }