Merge branch 'po/doc-branch' into maint
[git] / fetch-pack.c
1 #include "cache.h"
2 #include "repository.h"
3 #include "config.h"
4 #include "lockfile.h"
5 #include "refs.h"
6 #include "pkt-line.h"
7 #include "commit.h"
8 #include "tag.h"
9 #include "exec-cmd.h"
10 #include "pack.h"
11 #include "sideband.h"
12 #include "fetch-pack.h"
13 #include "remote.h"
14 #include "run-command.h"
15 #include "connect.h"
16 #include "transport.h"
17 #include "version.h"
18 #include "sha1-array.h"
19 #include "oidset.h"
20 #include "packfile.h"
21 #include "object-store.h"
22 #include "connected.h"
23 #include "fetch-negotiator.h"
24 #include "fsck.h"
25
26 static int transfer_unpack_limit = -1;
27 static int fetch_unpack_limit = -1;
28 static int unpack_limit = 100;
29 static int prefer_ofs_delta = 1;
30 static int no_done;
31 static int deepen_since_ok;
32 static int deepen_not_ok;
33 static int fetch_fsck_objects = -1;
34 static int transfer_fsck_objects = -1;
35 static int agent_supported;
36 static int server_supports_filtering;
37 static struct lock_file shallow_lock;
38 static const char *alternate_shallow_file;
39 static char *negotiation_algorithm;
40 static struct strbuf fsck_msg_types = STRBUF_INIT;
41
42 /* Remember to update object flag allocation in object.h */
43 #define COMPLETE        (1U << 0)
44 #define ALTERNATE       (1U << 1)
45
46 /*
47  * After sending this many "have"s if we do not get any new ACK , we
48  * give up traversing our history.
49  */
50 #define MAX_IN_VAIN 256
51
52 static int multi_ack, use_sideband;
53 /* Allow specifying sha1 if it is a ref tip. */
54 #define ALLOW_TIP_SHA1  01
55 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
56 #define ALLOW_REACHABLE_SHA1    02
57 static unsigned int allow_unadvertised_object_request;
58
59 __attribute__((format (printf, 2, 3)))
60 static inline void print_verbose(const struct fetch_pack_args *args,
61                                  const char *fmt, ...)
62 {
63         va_list params;
64
65         if (!args->verbose)
66                 return;
67
68         va_start(params, fmt);
69         vfprintf(stderr, fmt, params);
70         va_end(params);
71         fputc('\n', stderr);
72 }
73
74 struct alternate_object_cache {
75         struct object **items;
76         size_t nr, alloc;
77 };
78
79 static void cache_one_alternate(const struct object_id *oid,
80                                 void *vcache)
81 {
82         struct alternate_object_cache *cache = vcache;
83         struct object *obj = parse_object(the_repository, oid);
84
85         if (!obj || (obj->flags & ALTERNATE))
86                 return;
87
88         obj->flags |= ALTERNATE;
89         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
90         cache->items[cache->nr++] = obj;
91 }
92
93 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
94                                       void (*cb)(struct fetch_negotiator *,
95                                                  struct object *))
96 {
97         static int initialized;
98         static struct alternate_object_cache cache;
99         size_t i;
100
101         if (!initialized) {
102                 for_each_alternate_ref(cache_one_alternate, &cache);
103                 initialized = 1;
104         }
105
106         for (i = 0; i < cache.nr; i++)
107                 cb(negotiator, cache.items[i]);
108 }
109
110 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
111                                const char *refname,
112                                const struct object_id *oid)
113 {
114         struct object *o = deref_tag(the_repository,
115                                      parse_object(the_repository, oid),
116                                      refname, 0);
117
118         if (o && o->type == OBJ_COMMIT)
119                 negotiator->add_tip(negotiator, (struct commit *)o);
120
121         return 0;
122 }
123
124 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
125                                    int flag, void *cb_data)
126 {
127         return rev_list_insert_ref(cb_data, refname, oid);
128 }
129
130 enum ack_type {
131         NAK = 0,
132         ACK,
133         ACK_continue,
134         ACK_common,
135         ACK_ready
136 };
137
138 static void consume_shallow_list(struct fetch_pack_args *args,
139                                  struct packet_reader *reader)
140 {
141         if (args->stateless_rpc && args->deepen) {
142                 /* If we sent a depth we will get back "duplicate"
143                  * shallow and unshallow commands every time there
144                  * is a block of have lines exchanged.
145                  */
146                 while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
147                         if (starts_with(reader->line, "shallow "))
148                                 continue;
149                         if (starts_with(reader->line, "unshallow "))
150                                 continue;
151                         die(_("git fetch-pack: expected shallow list"));
152                 }
153                 if (reader->status != PACKET_READ_FLUSH)
154                         die(_("git fetch-pack: expected a flush packet after shallow list"));
155         }
156 }
157
158 static enum ack_type get_ack(struct packet_reader *reader,
159                              struct object_id *result_oid)
160 {
161         int len;
162         const char *arg;
163
164         if (packet_reader_read(reader) != PACKET_READ_NORMAL)
165                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
166         len = reader->pktlen;
167
168         if (!strcmp(reader->line, "NAK"))
169                 return NAK;
170         if (skip_prefix(reader->line, "ACK ", &arg)) {
171                 if (!get_oid_hex(arg, result_oid)) {
172                         arg += 40;
173                         len -= arg - reader->line;
174                         if (len < 1)
175                                 return ACK;
176                         if (strstr(arg, "continue"))
177                                 return ACK_continue;
178                         if (strstr(arg, "common"))
179                                 return ACK_common;
180                         if (strstr(arg, "ready"))
181                                 return ACK_ready;
182                         return ACK;
183                 }
184         }
185         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
186 }
187
188 static void send_request(struct fetch_pack_args *args,
189                          int fd, struct strbuf *buf)
190 {
191         if (args->stateless_rpc) {
192                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
193                 packet_flush(fd);
194         } else {
195                 if (write_in_full(fd, buf->buf, buf->len) < 0)
196                         die_errno(_("unable to write to remote"));
197         }
198 }
199
200 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
201                                         struct object *obj)
202 {
203         rev_list_insert_ref(negotiator, NULL, &obj->oid);
204 }
205
206 #define INITIAL_FLUSH 16
207 #define PIPESAFE_FLUSH 32
208 #define LARGE_FLUSH 16384
209
210 static int next_flush(int stateless_rpc, int count)
211 {
212         if (stateless_rpc) {
213                 if (count < LARGE_FLUSH)
214                         count <<= 1;
215                 else
216                         count = count * 11 / 10;
217         } else {
218                 if (count < PIPESAFE_FLUSH)
219                         count <<= 1;
220                 else
221                         count += PIPESAFE_FLUSH;
222         }
223         return count;
224 }
225
226 static void mark_tips(struct fetch_negotiator *negotiator,
227                       const struct oid_array *negotiation_tips)
228 {
229         int i;
230
231         if (!negotiation_tips) {
232                 for_each_ref(rev_list_insert_ref_oid, negotiator);
233                 return;
234         }
235
236         for (i = 0; i < negotiation_tips->nr; i++)
237                 rev_list_insert_ref(negotiator, NULL,
238                                     &negotiation_tips->oid[i]);
239         return;
240 }
241
242 static int find_common(struct fetch_negotiator *negotiator,
243                        struct fetch_pack_args *args,
244                        int fd[2], struct object_id *result_oid,
245                        struct ref *refs)
246 {
247         int fetching;
248         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
249         const struct object_id *oid;
250         unsigned in_vain = 0;
251         int got_continue = 0;
252         int got_ready = 0;
253         struct strbuf req_buf = STRBUF_INIT;
254         size_t state_len = 0;
255         struct packet_reader reader;
256
257         if (args->stateless_rpc && multi_ack == 1)
258                 die(_("--stateless-rpc requires multi_ack_detailed"));
259
260         packet_reader_init(&reader, fd[0], NULL, 0,
261                            PACKET_READ_CHOMP_NEWLINE |
262                            PACKET_READ_DIE_ON_ERR_PACKET);
263
264         if (!args->no_dependents) {
265                 mark_tips(negotiator, args->negotiation_tips);
266                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
267         }
268
269         fetching = 0;
270         for ( ; refs ; refs = refs->next) {
271                 struct object_id *remote = &refs->old_oid;
272                 const char *remote_hex;
273                 struct object *o;
274
275                 /*
276                  * If that object is complete (i.e. it is an ancestor of a
277                  * local ref), we tell them we have it but do not have to
278                  * tell them about its ancestors, which they already know
279                  * about.
280                  *
281                  * We use lookup_object here because we are only
282                  * interested in the case we *know* the object is
283                  * reachable and we have already scanned it.
284                  *
285                  * Do this only if args->no_dependents is false (if it is true,
286                  * we cannot trust the object flags).
287                  */
288                 if (!args->no_dependents &&
289                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
290                                 (o->flags & COMPLETE)) {
291                         continue;
292                 }
293
294                 remote_hex = oid_to_hex(remote);
295                 if (!fetching) {
296                         struct strbuf c = STRBUF_INIT;
297                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
298                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
299                         if (no_done)            strbuf_addstr(&c, " no-done");
300                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
301                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
302                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
303                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
304                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
305                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
306                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
307                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
308                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
309                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
310                                                             git_user_agent_sanitized());
311                         if (args->filter_options.choice)
312                                 strbuf_addstr(&c, " filter");
313                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
314                         strbuf_release(&c);
315                 } else
316                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
317                 fetching++;
318         }
319
320         if (!fetching) {
321                 strbuf_release(&req_buf);
322                 packet_flush(fd[1]);
323                 return 1;
324         }
325
326         if (is_repository_shallow(the_repository))
327                 write_shallow_commits(&req_buf, 1, NULL);
328         if (args->depth > 0)
329                 packet_buf_write(&req_buf, "deepen %d", args->depth);
330         if (args->deepen_since) {
331                 timestamp_t max_age = approxidate(args->deepen_since);
332                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
333         }
334         if (args->deepen_not) {
335                 int i;
336                 for (i = 0; i < args->deepen_not->nr; i++) {
337                         struct string_list_item *s = args->deepen_not->items + i;
338                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
339                 }
340         }
341         if (server_supports_filtering && args->filter_options.choice) {
342                 struct strbuf expanded_filter_spec = STRBUF_INIT;
343                 expand_list_objects_filter_spec(&args->filter_options,
344                                                 &expanded_filter_spec);
345                 packet_buf_write(&req_buf, "filter %s",
346                                  expanded_filter_spec.buf);
347                 strbuf_release(&expanded_filter_spec);
348         }
349         packet_buf_flush(&req_buf);
350         state_len = req_buf.len;
351
352         if (args->deepen) {
353                 const char *arg;
354                 struct object_id oid;
355
356                 send_request(args, fd[1], &req_buf);
357                 while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
358                         if (skip_prefix(reader.line, "shallow ", &arg)) {
359                                 if (get_oid_hex(arg, &oid))
360                                         die(_("invalid shallow line: %s"), reader.line);
361                                 register_shallow(the_repository, &oid);
362                                 continue;
363                         }
364                         if (skip_prefix(reader.line, "unshallow ", &arg)) {
365                                 if (get_oid_hex(arg, &oid))
366                                         die(_("invalid unshallow line: %s"), reader.line);
367                                 if (!lookup_object(the_repository, oid.hash))
368                                         die(_("object not found: %s"), reader.line);
369                                 /* make sure that it is parsed as shallow */
370                                 if (!parse_object(the_repository, &oid))
371                                         die(_("error in object: %s"), reader.line);
372                                 if (unregister_shallow(&oid))
373                                         die(_("no shallow found: %s"), reader.line);
374                                 continue;
375                         }
376                         die(_("expected shallow/unshallow, got %s"), reader.line);
377                 }
378         } else if (!args->stateless_rpc)
379                 send_request(args, fd[1], &req_buf);
380
381         if (!args->stateless_rpc) {
382                 /* If we aren't using the stateless-rpc interface
383                  * we don't need to retain the headers.
384                  */
385                 strbuf_setlen(&req_buf, 0);
386                 state_len = 0;
387         }
388
389         flushes = 0;
390         retval = -1;
391         if (args->no_dependents)
392                 goto done;
393         while ((oid = negotiator->next(negotiator))) {
394                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
395                 print_verbose(args, "have %s", oid_to_hex(oid));
396                 in_vain++;
397                 if (flush_at <= ++count) {
398                         int ack;
399
400                         packet_buf_flush(&req_buf);
401                         send_request(args, fd[1], &req_buf);
402                         strbuf_setlen(&req_buf, state_len);
403                         flushes++;
404                         flush_at = next_flush(args->stateless_rpc, count);
405
406                         /*
407                          * We keep one window "ahead" of the other side, and
408                          * will wait for an ACK only on the next one
409                          */
410                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
411                                 continue;
412
413                         consume_shallow_list(args, &reader);
414                         do {
415                                 ack = get_ack(&reader, result_oid);
416                                 if (ack)
417                                         print_verbose(args, _("got %s %d %s"), "ack",
418                                                       ack, oid_to_hex(result_oid));
419                                 switch (ack) {
420                                 case ACK:
421                                         flushes = 0;
422                                         multi_ack = 0;
423                                         retval = 0;
424                                         goto done;
425                                 case ACK_common:
426                                 case ACK_ready:
427                                 case ACK_continue: {
428                                         struct commit *commit =
429                                                 lookup_commit(the_repository,
430                                                               result_oid);
431                                         int was_common;
432
433                                         if (!commit)
434                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
435                                         was_common = negotiator->ack(negotiator, commit);
436                                         if (args->stateless_rpc
437                                          && ack == ACK_common
438                                          && !was_common) {
439                                                 /* We need to replay the have for this object
440                                                  * on the next RPC request so the peer knows
441                                                  * it is in common with us.
442                                                  */
443                                                 const char *hex = oid_to_hex(result_oid);
444                                                 packet_buf_write(&req_buf, "have %s\n", hex);
445                                                 state_len = req_buf.len;
446                                                 /*
447                                                  * Reset in_vain because an ack
448                                                  * for this commit has not been
449                                                  * seen.
450                                                  */
451                                                 in_vain = 0;
452                                         } else if (!args->stateless_rpc
453                                                    || ack != ACK_common)
454                                                 in_vain = 0;
455                                         retval = 0;
456                                         got_continue = 1;
457                                         if (ack == ACK_ready)
458                                                 got_ready = 1;
459                                         break;
460                                         }
461                                 }
462                         } while (ack);
463                         flushes--;
464                         if (got_continue && MAX_IN_VAIN < in_vain) {
465                                 print_verbose(args, _("giving up"));
466                                 break; /* give up */
467                         }
468                         if (got_ready)
469                                 break;
470                 }
471         }
472 done:
473         if (!got_ready || !no_done) {
474                 packet_buf_write(&req_buf, "done\n");
475                 send_request(args, fd[1], &req_buf);
476         }
477         print_verbose(args, _("done"));
478         if (retval != 0) {
479                 multi_ack = 0;
480                 flushes++;
481         }
482         strbuf_release(&req_buf);
483
484         if (!got_ready || !no_done)
485                 consume_shallow_list(args, &reader);
486         while (flushes || multi_ack) {
487                 int ack = get_ack(&reader, result_oid);
488                 if (ack) {
489                         print_verbose(args, _("got %s (%d) %s"), "ack",
490                                       ack, oid_to_hex(result_oid));
491                         if (ack == ACK)
492                                 return 0;
493                         multi_ack = 1;
494                         continue;
495                 }
496                 flushes--;
497         }
498         /* it is no error to fetch into a completely empty repo */
499         return count ? retval : 0;
500 }
501
502 static struct commit_list *complete;
503
504 static int mark_complete(const struct object_id *oid)
505 {
506         struct object *o = parse_object(the_repository, oid);
507
508         while (o && o->type == OBJ_TAG) {
509                 struct tag *t = (struct tag *) o;
510                 if (!t->tagged)
511                         break; /* broken repository */
512                 o->flags |= COMPLETE;
513                 o = parse_object(the_repository, &t->tagged->oid);
514         }
515         if (o && o->type == OBJ_COMMIT) {
516                 struct commit *commit = (struct commit *)o;
517                 if (!(commit->object.flags & COMPLETE)) {
518                         commit->object.flags |= COMPLETE;
519                         commit_list_insert(commit, &complete);
520                 }
521         }
522         return 0;
523 }
524
525 static int mark_complete_oid(const char *refname, const struct object_id *oid,
526                              int flag, void *cb_data)
527 {
528         return mark_complete(oid);
529 }
530
531 static void mark_recent_complete_commits(struct fetch_pack_args *args,
532                                          timestamp_t cutoff)
533 {
534         while (complete && cutoff <= complete->item->date) {
535                 print_verbose(args, _("Marking %s as complete"),
536                               oid_to_hex(&complete->item->object.oid));
537                 pop_most_recent_commit(&complete, COMPLETE);
538         }
539 }
540
541 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
542 {
543         for (; refs; refs = refs->next)
544                 oidset_insert(oids, &refs->old_oid);
545 }
546
547 static int is_unmatched_ref(const struct ref *ref)
548 {
549         struct object_id oid;
550         const char *p;
551         return  ref->match_status == REF_NOT_MATCHED &&
552                 !parse_oid_hex(ref->name, &oid, &p) &&
553                 *p == '\0' &&
554                 oideq(&oid, &ref->old_oid);
555 }
556
557 static void filter_refs(struct fetch_pack_args *args,
558                         struct ref **refs,
559                         struct ref **sought, int nr_sought)
560 {
561         struct ref *newlist = NULL;
562         struct ref **newtail = &newlist;
563         struct ref *unmatched = NULL;
564         struct ref *ref, *next;
565         struct oidset tip_oids = OIDSET_INIT;
566         int i;
567         int strict = !(allow_unadvertised_object_request &
568                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
569
570         i = 0;
571         for (ref = *refs; ref; ref = next) {
572                 int keep = 0;
573                 next = ref->next;
574
575                 if (starts_with(ref->name, "refs/") &&
576                     check_refname_format(ref->name, 0)) {
577                         /*
578                          * trash or a peeled value; do not even add it to
579                          * unmatched list
580                          */
581                         free_one_ref(ref);
582                         continue;
583                 } else {
584                         while (i < nr_sought) {
585                                 int cmp = strcmp(ref->name, sought[i]->name);
586                                 if (cmp < 0)
587                                         break; /* definitely do not have it */
588                                 else if (cmp == 0) {
589                                         keep = 1; /* definitely have it */
590                                         sought[i]->match_status = REF_MATCHED;
591                                 }
592                                 i++;
593                         }
594
595                         if (!keep && args->fetch_all &&
596                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
597                                 keep = 1;
598                 }
599
600                 if (keep) {
601                         *newtail = ref;
602                         ref->next = NULL;
603                         newtail = &ref->next;
604                 } else {
605                         ref->next = unmatched;
606                         unmatched = ref;
607                 }
608         }
609
610         if (strict) {
611                 for (i = 0; i < nr_sought; i++) {
612                         ref = sought[i];
613                         if (!is_unmatched_ref(ref))
614                                 continue;
615
616                         add_refs_to_oidset(&tip_oids, unmatched);
617                         add_refs_to_oidset(&tip_oids, newlist);
618                         break;
619                 }
620         }
621
622         /* Append unmatched requests to the list */
623         for (i = 0; i < nr_sought; i++) {
624                 ref = sought[i];
625                 if (!is_unmatched_ref(ref))
626                         continue;
627
628                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
629                         ref->match_status = REF_MATCHED;
630                         *newtail = copy_ref(ref);
631                         newtail = &(*newtail)->next;
632                 } else {
633                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
634                 }
635         }
636
637         oidset_clear(&tip_oids);
638         free_refs(unmatched);
639
640         *refs = newlist;
641 }
642
643 static void mark_alternate_complete(struct fetch_negotiator *unused,
644                                     struct object *obj)
645 {
646         mark_complete(&obj->oid);
647 }
648
649 struct loose_object_iter {
650         struct oidset *loose_object_set;
651         struct ref *refs;
652 };
653
654 /*
655  * Mark recent commits available locally and reachable from a local ref as
656  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
657  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
658  * thus do not need COMMON_REF marks).
659  *
660  * The cutoff time for recency is determined by this heuristic: it is the
661  * earliest commit time of the objects in refs that are commits and that we know
662  * the commit time of.
663  */
664 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
665                                          struct fetch_pack_args *args,
666                                          struct ref **refs)
667 {
668         struct ref *ref;
669         int old_save_commit_buffer = save_commit_buffer;
670         timestamp_t cutoff = 0;
671
672         save_commit_buffer = 0;
673
674         for (ref = *refs; ref; ref = ref->next) {
675                 struct object *o;
676
677                 if (!has_object_file_with_flags(&ref->old_oid,
678                                                 OBJECT_INFO_QUICK))
679                         continue;
680                 o = parse_object(the_repository, &ref->old_oid);
681                 if (!o)
682                         continue;
683
684                 /* We already have it -- which may mean that we were
685                  * in sync with the other side at some time after
686                  * that (it is OK if we guess wrong here).
687                  */
688                 if (o->type == OBJ_COMMIT) {
689                         struct commit *commit = (struct commit *)o;
690                         if (!cutoff || cutoff < commit->date)
691                                 cutoff = commit->date;
692                 }
693         }
694
695         if (!args->deepen) {
696                 for_each_ref(mark_complete_oid, NULL);
697                 for_each_cached_alternate(NULL, mark_alternate_complete);
698                 commit_list_sort_by_date(&complete);
699                 if (cutoff)
700                         mark_recent_complete_commits(args, cutoff);
701         }
702
703         /*
704          * Mark all complete remote refs as common refs.
705          * Don't mark them common yet; the server has to be told so first.
706          */
707         for (ref = *refs; ref; ref = ref->next) {
708                 struct object *o = deref_tag(the_repository,
709                                              lookup_object(the_repository,
710                                              ref->old_oid.hash),
711                                              NULL, 0);
712
713                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
714                         continue;
715
716                 negotiator->known_common(negotiator,
717                                          (struct commit *)o);
718         }
719
720         save_commit_buffer = old_save_commit_buffer;
721 }
722
723 /*
724  * Returns 1 if every object pointed to by the given remote refs is available
725  * locally and reachable from a local ref, and 0 otherwise.
726  */
727 static int everything_local(struct fetch_pack_args *args,
728                             struct ref **refs)
729 {
730         struct ref *ref;
731         int retval;
732
733         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
734                 const struct object_id *remote = &ref->old_oid;
735                 struct object *o;
736
737                 o = lookup_object(the_repository, remote->hash);
738                 if (!o || !(o->flags & COMPLETE)) {
739                         retval = 0;
740                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
741                                       ref->name);
742                         continue;
743                 }
744                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
745                               ref->name);
746         }
747
748         return retval;
749 }
750
751 static int sideband_demux(int in, int out, void *data)
752 {
753         int *xd = data;
754         int ret;
755
756         ret = recv_sideband("fetch-pack", xd[0], out);
757         close(out);
758         return ret;
759 }
760
761 static int get_pack(struct fetch_pack_args *args,
762                     int xd[2], char **pack_lockfile)
763 {
764         struct async demux;
765         int do_keep = args->keep_pack;
766         const char *cmd_name;
767         struct pack_header header;
768         int pass_header = 0;
769         struct child_process cmd = CHILD_PROCESS_INIT;
770         int ret;
771
772         memset(&demux, 0, sizeof(demux));
773         if (use_sideband) {
774                 /* xd[] is talking with upload-pack; subprocess reads from
775                  * xd[0], spits out band#2 to stderr, and feeds us band#1
776                  * through demux->out.
777                  */
778                 demux.proc = sideband_demux;
779                 demux.data = xd;
780                 demux.out = -1;
781                 demux.isolate_sigpipe = 1;
782                 if (start_async(&demux))
783                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
784         }
785         else
786                 demux.out = xd[0];
787
788         if (!args->keep_pack && unpack_limit) {
789
790                 if (read_pack_header(demux.out, &header))
791                         die(_("protocol error: bad pack header"));
792                 pass_header = 1;
793                 if (ntohl(header.hdr_entries) < unpack_limit)
794                         do_keep = 0;
795                 else
796                         do_keep = 1;
797         }
798
799         if (alternate_shallow_file) {
800                 argv_array_push(&cmd.args, "--shallow-file");
801                 argv_array_push(&cmd.args, alternate_shallow_file);
802         }
803
804         if (do_keep || args->from_promisor) {
805                 if (pack_lockfile)
806                         cmd.out = -1;
807                 cmd_name = "index-pack";
808                 argv_array_push(&cmd.args, cmd_name);
809                 argv_array_push(&cmd.args, "--stdin");
810                 if (!args->quiet && !args->no_progress)
811                         argv_array_push(&cmd.args, "-v");
812                 if (args->use_thin_pack)
813                         argv_array_push(&cmd.args, "--fix-thin");
814                 if (do_keep && (args->lock_pack || unpack_limit)) {
815                         char hostname[HOST_NAME_MAX + 1];
816                         if (xgethostname(hostname, sizeof(hostname)))
817                                 xsnprintf(hostname, sizeof(hostname), "localhost");
818                         argv_array_pushf(&cmd.args,
819                                         "--keep=fetch-pack %"PRIuMAX " on %s",
820                                         (uintmax_t)getpid(), hostname);
821                 }
822                 if (args->check_self_contained_and_connected)
823                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
824                 if (args->from_promisor)
825                         argv_array_push(&cmd.args, "--promisor");
826         }
827         else {
828                 cmd_name = "unpack-objects";
829                 argv_array_push(&cmd.args, cmd_name);
830                 if (args->quiet || args->no_progress)
831                         argv_array_push(&cmd.args, "-q");
832                 args->check_self_contained_and_connected = 0;
833         }
834
835         if (pass_header)
836                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
837                                  ntohl(header.hdr_version),
838                                  ntohl(header.hdr_entries));
839         if (fetch_fsck_objects >= 0
840             ? fetch_fsck_objects
841             : transfer_fsck_objects >= 0
842             ? transfer_fsck_objects
843             : 0) {
844                 if (args->from_promisor)
845                         /*
846                          * We cannot use --strict in index-pack because it
847                          * checks both broken objects and links, but we only
848                          * want to check for broken objects.
849                          */
850                         argv_array_push(&cmd.args, "--fsck-objects");
851                 else
852                         argv_array_pushf(&cmd.args, "--strict%s",
853                                          fsck_msg_types.buf);
854         }
855
856         cmd.in = demux.out;
857         cmd.git_cmd = 1;
858         if (start_command(&cmd))
859                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
860         if (do_keep && pack_lockfile) {
861                 *pack_lockfile = index_pack_lockfile(cmd.out);
862                 close(cmd.out);
863         }
864
865         if (!use_sideband)
866                 /* Closed by start_command() */
867                 xd[0] = -1;
868
869         ret = finish_command(&cmd);
870         if (!ret || (args->check_self_contained_and_connected && ret == 1))
871                 args->self_contained_and_connected =
872                         args->check_self_contained_and_connected &&
873                         ret == 0;
874         else
875                 die(_("%s failed"), cmd_name);
876         if (use_sideband && finish_async(&demux))
877                 die(_("error in sideband demultiplexer"));
878         return 0;
879 }
880
881 static int cmp_ref_by_name(const void *a_, const void *b_)
882 {
883         const struct ref *a = *((const struct ref **)a_);
884         const struct ref *b = *((const struct ref **)b_);
885         return strcmp(a->name, b->name);
886 }
887
888 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
889                                  int fd[2],
890                                  const struct ref *orig_ref,
891                                  struct ref **sought, int nr_sought,
892                                  struct shallow_info *si,
893                                  char **pack_lockfile)
894 {
895         struct ref *ref = copy_ref_list(orig_ref);
896         struct object_id oid;
897         const char *agent_feature;
898         int agent_len;
899         struct fetch_negotiator negotiator;
900         fetch_negotiator_init(&negotiator, negotiation_algorithm);
901
902         sort_ref_list(&ref, ref_compare_name);
903         QSORT(sought, nr_sought, cmp_ref_by_name);
904
905         if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
906                 die(_("Server does not support shallow clients"));
907         if (args->depth > 0 || args->deepen_since || args->deepen_not)
908                 args->deepen = 1;
909         if (server_supports("multi_ack_detailed")) {
910                 print_verbose(args, _("Server supports multi_ack_detailed"));
911                 multi_ack = 2;
912                 if (server_supports("no-done")) {
913                         print_verbose(args, _("Server supports no-done"));
914                         if (args->stateless_rpc)
915                                 no_done = 1;
916                 }
917         }
918         else if (server_supports("multi_ack")) {
919                 print_verbose(args, _("Server supports multi_ack"));
920                 multi_ack = 1;
921         }
922         if (server_supports("side-band-64k")) {
923                 print_verbose(args, _("Server supports side-band-64k"));
924                 use_sideband = 2;
925         }
926         else if (server_supports("side-band")) {
927                 print_verbose(args, _("Server supports side-band"));
928                 use_sideband = 1;
929         }
930         if (server_supports("allow-tip-sha1-in-want")) {
931                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
932                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
933         }
934         if (server_supports("allow-reachable-sha1-in-want")) {
935                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
936                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
937         }
938         if (!server_supports("thin-pack"))
939                 args->use_thin_pack = 0;
940         if (!server_supports("no-progress"))
941                 args->no_progress = 0;
942         if (!server_supports("include-tag"))
943                 args->include_tag = 0;
944         if (server_supports("ofs-delta"))
945                 print_verbose(args, _("Server supports ofs-delta"));
946         else
947                 prefer_ofs_delta = 0;
948
949         if (server_supports("filter")) {
950                 server_supports_filtering = 1;
951                 print_verbose(args, _("Server supports filter"));
952         } else if (args->filter_options.choice) {
953                 warning("filtering not recognized by server, ignoring");
954         }
955
956         if ((agent_feature = server_feature_value("agent", &agent_len))) {
957                 agent_supported = 1;
958                 if (agent_len)
959                         print_verbose(args, _("Server version is %.*s"),
960                                       agent_len, agent_feature);
961         }
962         if (server_supports("deepen-since"))
963                 deepen_since_ok = 1;
964         else if (args->deepen_since)
965                 die(_("Server does not support --shallow-since"));
966         if (server_supports("deepen-not"))
967                 deepen_not_ok = 1;
968         else if (args->deepen_not)
969                 die(_("Server does not support --shallow-exclude"));
970         if (!server_supports("deepen-relative") && args->deepen_relative)
971                 die(_("Server does not support --deepen"));
972
973         if (!args->no_dependents) {
974                 mark_complete_and_common_ref(&negotiator, args, &ref);
975                 filter_refs(args, &ref, sought, nr_sought);
976                 if (everything_local(args, &ref)) {
977                         packet_flush(fd[1]);
978                         goto all_done;
979                 }
980         } else {
981                 filter_refs(args, &ref, sought, nr_sought);
982         }
983         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
984                 if (!args->keep_pack)
985                         /* When cloning, it is not unusual to have
986                          * no common commit.
987                          */
988                         warning(_("no common commits"));
989
990         if (args->stateless_rpc)
991                 packet_flush(fd[1]);
992         if (args->deepen)
993                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
994                                         NULL);
995         else if (si->nr_ours || si->nr_theirs)
996                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
997         else
998                 alternate_shallow_file = NULL;
999         if (get_pack(args, fd, pack_lockfile))
1000                 die(_("git fetch-pack: fetch failed."));
1001
1002  all_done:
1003         negotiator.release(&negotiator);
1004         return ref;
1005 }
1006
1007 static void add_shallow_requests(struct strbuf *req_buf,
1008                                  const struct fetch_pack_args *args)
1009 {
1010         if (is_repository_shallow(the_repository))
1011                 write_shallow_commits(req_buf, 1, NULL);
1012         if (args->depth > 0)
1013                 packet_buf_write(req_buf, "deepen %d", args->depth);
1014         if (args->deepen_since) {
1015                 timestamp_t max_age = approxidate(args->deepen_since);
1016                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1017         }
1018         if (args->deepen_not) {
1019                 int i;
1020                 for (i = 0; i < args->deepen_not->nr; i++) {
1021                         struct string_list_item *s = args->deepen_not->items + i;
1022                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1023                 }
1024         }
1025         if (args->deepen_relative)
1026                 packet_buf_write(req_buf, "deepen-relative\n");
1027 }
1028
1029 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1030 {
1031         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1032
1033         for ( ; wants ; wants = wants->next) {
1034                 const struct object_id *remote = &wants->old_oid;
1035                 struct object *o;
1036
1037                 /*
1038                  * If that object is complete (i.e. it is an ancestor of a
1039                  * local ref), we tell them we have it but do not have to
1040                  * tell them about its ancestors, which they already know
1041                  * about.
1042                  *
1043                  * We use lookup_object here because we are only
1044                  * interested in the case we *know* the object is
1045                  * reachable and we have already scanned it.
1046                  *
1047                  * Do this only if args->no_dependents is false (if it is true,
1048                  * we cannot trust the object flags).
1049                  */
1050                 if (!no_dependents &&
1051                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1052                     (o->flags & COMPLETE)) {
1053                         continue;
1054                 }
1055
1056                 if (!use_ref_in_want || wants->exact_oid)
1057                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1058                 else
1059                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1060         }
1061 }
1062
1063 static void add_common(struct strbuf *req_buf, struct oidset *common)
1064 {
1065         struct oidset_iter iter;
1066         const struct object_id *oid;
1067         oidset_iter_init(common, &iter);
1068
1069         while ((oid = oidset_iter_next(&iter))) {
1070                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1071         }
1072 }
1073
1074 static int add_haves(struct fetch_negotiator *negotiator,
1075                      struct strbuf *req_buf,
1076                      int *haves_to_send, int *in_vain)
1077 {
1078         int ret = 0;
1079         int haves_added = 0;
1080         const struct object_id *oid;
1081
1082         while ((oid = negotiator->next(negotiator))) {
1083                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1084                 if (++haves_added >= *haves_to_send)
1085                         break;
1086         }
1087
1088         *in_vain += haves_added;
1089         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1090                 /* Send Done */
1091                 packet_buf_write(req_buf, "done\n");
1092                 ret = 1;
1093         }
1094
1095         /* Increase haves to send on next round */
1096         *haves_to_send = next_flush(1, *haves_to_send);
1097
1098         return ret;
1099 }
1100
1101 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1102                               const struct fetch_pack_args *args,
1103                               const struct ref *wants, struct oidset *common,
1104                               int *haves_to_send, int *in_vain,
1105                               int sideband_all)
1106 {
1107         int ret = 0;
1108         struct strbuf req_buf = STRBUF_INIT;
1109
1110         if (server_supports_v2("fetch", 1))
1111                 packet_buf_write(&req_buf, "command=fetch");
1112         if (server_supports_v2("agent", 0))
1113                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1114         if (args->server_options && args->server_options->nr &&
1115             server_supports_v2("server-option", 1)) {
1116                 int i;
1117                 for (i = 0; i < args->server_options->nr; i++)
1118                         packet_buf_write(&req_buf, "server-option=%s",
1119                                          args->server_options->items[i].string);
1120         }
1121
1122         packet_buf_delim(&req_buf);
1123         if (args->use_thin_pack)
1124                 packet_buf_write(&req_buf, "thin-pack");
1125         if (args->no_progress)
1126                 packet_buf_write(&req_buf, "no-progress");
1127         if (args->include_tag)
1128                 packet_buf_write(&req_buf, "include-tag");
1129         if (prefer_ofs_delta)
1130                 packet_buf_write(&req_buf, "ofs-delta");
1131         if (sideband_all)
1132                 packet_buf_write(&req_buf, "sideband-all");
1133
1134         /* Add shallow-info and deepen request */
1135         if (server_supports_feature("fetch", "shallow", 0))
1136                 add_shallow_requests(&req_buf, args);
1137         else if (is_repository_shallow(the_repository) || args->deepen)
1138                 die(_("Server does not support shallow requests"));
1139
1140         /* Add filter */
1141         if (server_supports_feature("fetch", "filter", 0) &&
1142             args->filter_options.choice) {
1143                 struct strbuf expanded_filter_spec = STRBUF_INIT;
1144                 print_verbose(args, _("Server supports filter"));
1145                 expand_list_objects_filter_spec(&args->filter_options,
1146                                                 &expanded_filter_spec);
1147                 packet_buf_write(&req_buf, "filter %s",
1148                                  expanded_filter_spec.buf);
1149                 strbuf_release(&expanded_filter_spec);
1150         } else if (args->filter_options.choice) {
1151                 warning("filtering not recognized by server, ignoring");
1152         }
1153
1154         /* add wants */
1155         add_wants(args->no_dependents, wants, &req_buf);
1156
1157         if (args->no_dependents) {
1158                 packet_buf_write(&req_buf, "done");
1159                 ret = 1;
1160         } else {
1161                 /* Add all of the common commits we've found in previous rounds */
1162                 add_common(&req_buf, common);
1163
1164                 /* Add initial haves */
1165                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1166         }
1167
1168         /* Send request */
1169         packet_buf_flush(&req_buf);
1170         if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
1171                 die_errno(_("unable to write request to remote"));
1172
1173         strbuf_release(&req_buf);
1174         return ret;
1175 }
1176
1177 /*
1178  * Processes a section header in a server's response and checks if it matches
1179  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1180  * not consumed); if 0, the line will be consumed and the function will die if
1181  * the section header doesn't match what was expected.
1182  */
1183 static int process_section_header(struct packet_reader *reader,
1184                                   const char *section, int peek)
1185 {
1186         int ret;
1187
1188         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1189                 die(_("error reading section header '%s'"), section);
1190
1191         ret = !strcmp(reader->line, section);
1192
1193         if (!peek) {
1194                 if (!ret)
1195                         die(_("expected '%s', received '%s'"),
1196                             section, reader->line);
1197                 packet_reader_read(reader);
1198         }
1199
1200         return ret;
1201 }
1202
1203 static int process_acks(struct fetch_negotiator *negotiator,
1204                         struct packet_reader *reader,
1205                         struct oidset *common)
1206 {
1207         /* received */
1208         int received_ready = 0;
1209         int received_ack = 0;
1210
1211         process_section_header(reader, "acknowledgments", 0);
1212         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1213                 const char *arg;
1214
1215                 if (!strcmp(reader->line, "NAK"))
1216                         continue;
1217
1218                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1219                         struct object_id oid;
1220                         if (!get_oid_hex(arg, &oid)) {
1221                                 struct commit *commit;
1222                                 oidset_insert(common, &oid);
1223                                 commit = lookup_commit(the_repository, &oid);
1224                                 negotiator->ack(negotiator, commit);
1225                         }
1226                         continue;
1227                 }
1228
1229                 if (!strcmp(reader->line, "ready")) {
1230                         received_ready = 1;
1231                         continue;
1232                 }
1233
1234                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1235         }
1236
1237         if (reader->status != PACKET_READ_FLUSH &&
1238             reader->status != PACKET_READ_DELIM)
1239                 die(_("error processing acks: %d"), reader->status);
1240
1241         /*
1242          * If an "acknowledgments" section is sent, a packfile is sent if and
1243          * only if "ready" was sent in this section. The other sections
1244          * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1245          * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1246          * otherwise.
1247          */
1248         if (received_ready && reader->status != PACKET_READ_DELIM)
1249                 die(_("expected packfile to be sent after 'ready'"));
1250         if (!received_ready && reader->status != PACKET_READ_FLUSH)
1251                 die(_("expected no other sections to be sent after no 'ready'"));
1252
1253         /* return 0 if no common, 1 if there are common, or 2 if ready */
1254         return received_ready ? 2 : (received_ack ? 1 : 0);
1255 }
1256
1257 static void receive_shallow_info(struct fetch_pack_args *args,
1258                                  struct packet_reader *reader,
1259                                  struct oid_array *shallows,
1260                                  struct shallow_info *si)
1261 {
1262         int unshallow_received = 0;
1263
1264         process_section_header(reader, "shallow-info", 0);
1265         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1266                 const char *arg;
1267                 struct object_id oid;
1268
1269                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1270                         if (get_oid_hex(arg, &oid))
1271                                 die(_("invalid shallow line: %s"), reader->line);
1272                         oid_array_append(shallows, &oid);
1273                         continue;
1274                 }
1275                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1276                         if (get_oid_hex(arg, &oid))
1277                                 die(_("invalid unshallow line: %s"), reader->line);
1278                         if (!lookup_object(the_repository, oid.hash))
1279                                 die(_("object not found: %s"), reader->line);
1280                         /* make sure that it is parsed as shallow */
1281                         if (!parse_object(the_repository, &oid))
1282                                 die(_("error in object: %s"), reader->line);
1283                         if (unregister_shallow(&oid))
1284                                 die(_("no shallow found: %s"), reader->line);
1285                         unshallow_received = 1;
1286                         continue;
1287                 }
1288                 die(_("expected shallow/unshallow, got %s"), reader->line);
1289         }
1290
1291         if (reader->status != PACKET_READ_FLUSH &&
1292             reader->status != PACKET_READ_DELIM)
1293                 die(_("error processing shallow info: %d"), reader->status);
1294
1295         if (args->deepen || unshallow_received) {
1296                 /*
1297                  * Treat these as shallow lines caused by our depth settings.
1298                  * In v0, these lines cannot cause refs to be rejected; do the
1299                  * same.
1300                  */
1301                 int i;
1302
1303                 for (i = 0; i < shallows->nr; i++)
1304                         register_shallow(the_repository, &shallows->oid[i]);
1305                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1306                                         NULL);
1307                 args->deepen = 1;
1308         } else if (shallows->nr) {
1309                 /*
1310                  * Treat these as shallow lines caused by the remote being
1311                  * shallow. In v0, remote refs that reach these objects are
1312                  * rejected (unless --update-shallow is set); do the same.
1313                  */
1314                 prepare_shallow_info(si, shallows);
1315                 if (si->nr_ours || si->nr_theirs)
1316                         alternate_shallow_file =
1317                                 setup_temporary_shallow(si->shallow);
1318                 else
1319                         alternate_shallow_file = NULL;
1320         } else {
1321                 alternate_shallow_file = NULL;
1322         }
1323 }
1324
1325 static int cmp_name_ref(const void *name, const void *ref)
1326 {
1327         return strcmp(name, (*(struct ref **)ref)->name);
1328 }
1329
1330 static void receive_wanted_refs(struct packet_reader *reader,
1331                                 struct ref **sought, int nr_sought)
1332 {
1333         process_section_header(reader, "wanted-refs", 0);
1334         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1335                 struct object_id oid;
1336                 const char *end;
1337                 struct ref **found;
1338
1339                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1340                         die(_("expected wanted-ref, got '%s'"), reader->line);
1341
1342                 found = bsearch(end, sought, nr_sought, sizeof(*sought),
1343                                 cmp_name_ref);
1344                 if (!found)
1345                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1346                 oidcpy(&(*found)->old_oid, &oid);
1347         }
1348
1349         if (reader->status != PACKET_READ_DELIM)
1350                 die(_("error processing wanted refs: %d"), reader->status);
1351 }
1352
1353 enum fetch_state {
1354         FETCH_CHECK_LOCAL = 0,
1355         FETCH_SEND_REQUEST,
1356         FETCH_PROCESS_ACKS,
1357         FETCH_GET_PACK,
1358         FETCH_DONE,
1359 };
1360
1361 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1362                                     int fd[2],
1363                                     const struct ref *orig_ref,
1364                                     struct ref **sought, int nr_sought,
1365                                     struct oid_array *shallows,
1366                                     struct shallow_info *si,
1367                                     char **pack_lockfile)
1368 {
1369         struct ref *ref = copy_ref_list(orig_ref);
1370         enum fetch_state state = FETCH_CHECK_LOCAL;
1371         struct oidset common = OIDSET_INIT;
1372         struct packet_reader reader;
1373         int in_vain = 0;
1374         int haves_to_send = INITIAL_FLUSH;
1375         struct fetch_negotiator negotiator;
1376         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1377         packet_reader_init(&reader, fd[0], NULL, 0,
1378                            PACKET_READ_CHOMP_NEWLINE |
1379                            PACKET_READ_DIE_ON_ERR_PACKET);
1380         if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
1381             server_supports_feature("fetch", "sideband-all", 0)) {
1382                 reader.use_sideband = 1;
1383                 reader.me = "fetch-pack";
1384         }
1385
1386         while (state != FETCH_DONE) {
1387                 switch (state) {
1388                 case FETCH_CHECK_LOCAL:
1389                         sort_ref_list(&ref, ref_compare_name);
1390                         QSORT(sought, nr_sought, cmp_ref_by_name);
1391
1392                         /* v2 supports these by default */
1393                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1394                         use_sideband = 2;
1395                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1396                                 args->deepen = 1;
1397
1398                         /* Filter 'ref' by 'sought' and those that aren't local */
1399                         if (!args->no_dependents) {
1400                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1401                                 filter_refs(args, &ref, sought, nr_sought);
1402                                 if (everything_local(args, &ref))
1403                                         state = FETCH_DONE;
1404                                 else
1405                                         state = FETCH_SEND_REQUEST;
1406
1407                                 mark_tips(&negotiator, args->negotiation_tips);
1408                                 for_each_cached_alternate(&negotiator,
1409                                                           insert_one_alternate_object);
1410                         } else {
1411                                 filter_refs(args, &ref, sought, nr_sought);
1412                                 state = FETCH_SEND_REQUEST;
1413                         }
1414                         break;
1415                 case FETCH_SEND_REQUEST:
1416                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1417                                                &common,
1418                                                &haves_to_send, &in_vain,
1419                                                reader.use_sideband))
1420                                 state = FETCH_GET_PACK;
1421                         else
1422                                 state = FETCH_PROCESS_ACKS;
1423                         break;
1424                 case FETCH_PROCESS_ACKS:
1425                         /* Process ACKs/NAKs */
1426                         switch (process_acks(&negotiator, &reader, &common)) {
1427                         case 2:
1428                                 state = FETCH_GET_PACK;
1429                                 break;
1430                         case 1:
1431                                 in_vain = 0;
1432                                 /* fallthrough */
1433                         default:
1434                                 state = FETCH_SEND_REQUEST;
1435                                 break;
1436                         }
1437                         break;
1438                 case FETCH_GET_PACK:
1439                         /* Check for shallow-info section */
1440                         if (process_section_header(&reader, "shallow-info", 1))
1441                                 receive_shallow_info(args, &reader, shallows, si);
1442
1443                         if (process_section_header(&reader, "wanted-refs", 1))
1444                                 receive_wanted_refs(&reader, sought, nr_sought);
1445
1446                         /* get the pack */
1447                         process_section_header(&reader, "packfile", 0);
1448                         if (get_pack(args, fd, pack_lockfile))
1449                                 die(_("git fetch-pack: fetch failed."));
1450
1451                         state = FETCH_DONE;
1452                         break;
1453                 case FETCH_DONE:
1454                         continue;
1455                 }
1456         }
1457
1458         negotiator.release(&negotiator);
1459         oidset_clear(&common);
1460         return ref;
1461 }
1462
1463 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1464 {
1465         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1466                 const char *path;
1467
1468                 if (git_config_pathname(&path, var, value))
1469                         return 1;
1470                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1471                         fsck_msg_types.len ? ',' : '=', path);
1472                 free((char *)path);
1473                 return 0;
1474         }
1475
1476         if (skip_prefix(var, "fetch.fsck.", &var)) {
1477                 if (is_valid_msg_type(var, value))
1478                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1479                                 fsck_msg_types.len ? ',' : '=', var, value);
1480                 else
1481                         warning("Skipping unknown msg id '%s'", var);
1482                 return 0;
1483         }
1484
1485         return git_default_config(var, value, cb);
1486 }
1487
1488 static void fetch_pack_config(void)
1489 {
1490         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1491         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1492         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1493         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1494         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1495         git_config_get_string("fetch.negotiationalgorithm",
1496                               &negotiation_algorithm);
1497
1498         git_config(fetch_pack_config_cb, NULL);
1499 }
1500
1501 static void fetch_pack_setup(void)
1502 {
1503         static int did_setup;
1504         if (did_setup)
1505                 return;
1506         fetch_pack_config();
1507         if (0 <= transfer_unpack_limit)
1508                 unpack_limit = transfer_unpack_limit;
1509         else if (0 <= fetch_unpack_limit)
1510                 unpack_limit = fetch_unpack_limit;
1511         did_setup = 1;
1512 }
1513
1514 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1515 {
1516         struct string_list names = STRING_LIST_INIT_NODUP;
1517         int src, dst;
1518
1519         for (src = dst = 0; src < nr; src++) {
1520                 struct string_list_item *item;
1521                 item = string_list_insert(&names, ref[src]->name);
1522                 if (item->util)
1523                         continue; /* already have it */
1524                 item->util = ref[src];
1525                 if (src != dst)
1526                         ref[dst] = ref[src];
1527                 dst++;
1528         }
1529         for (src = dst; src < nr; src++)
1530                 ref[src] = NULL;
1531         string_list_clear(&names, 0);
1532         return dst;
1533 }
1534
1535 static void update_shallow(struct fetch_pack_args *args,
1536                            struct ref **sought, int nr_sought,
1537                            struct shallow_info *si)
1538 {
1539         struct oid_array ref = OID_ARRAY_INIT;
1540         int *status;
1541         int i;
1542
1543         if (args->deepen && alternate_shallow_file) {
1544                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1545                         unlink_or_warn(git_path_shallow(the_repository));
1546                         rollback_lock_file(&shallow_lock);
1547                 } else
1548                         commit_lock_file(&shallow_lock);
1549                 alternate_shallow_file = NULL;
1550                 return;
1551         }
1552
1553         if (!si->shallow || !si->shallow->nr)
1554                 return;
1555
1556         if (args->cloning) {
1557                 /*
1558                  * remote is shallow, but this is a clone, there are
1559                  * no objects in repo to worry about. Accept any
1560                  * shallow points that exist in the pack (iow in repo
1561                  * after get_pack() and reprepare_packed_git())
1562                  */
1563                 struct oid_array extra = OID_ARRAY_INIT;
1564                 struct object_id *oid = si->shallow->oid;
1565                 for (i = 0; i < si->shallow->nr; i++)
1566                         if (has_object_file(&oid[i]))
1567                                 oid_array_append(&extra, &oid[i]);
1568                 if (extra.nr) {
1569                         setup_alternate_shallow(&shallow_lock,
1570                                                 &alternate_shallow_file,
1571                                                 &extra);
1572                         commit_lock_file(&shallow_lock);
1573                         alternate_shallow_file = NULL;
1574                 }
1575                 oid_array_clear(&extra);
1576                 return;
1577         }
1578
1579         if (!si->nr_ours && !si->nr_theirs)
1580                 return;
1581
1582         remove_nonexistent_theirs_shallow(si);
1583         if (!si->nr_ours && !si->nr_theirs)
1584                 return;
1585         for (i = 0; i < nr_sought; i++)
1586                 oid_array_append(&ref, &sought[i]->old_oid);
1587         si->ref = &ref;
1588
1589         if (args->update_shallow) {
1590                 /*
1591                  * remote is also shallow, .git/shallow may be updated
1592                  * so all refs can be accepted. Make sure we only add
1593                  * shallow roots that are actually reachable from new
1594                  * refs.
1595                  */
1596                 struct oid_array extra = OID_ARRAY_INIT;
1597                 struct object_id *oid = si->shallow->oid;
1598                 assign_shallow_commits_to_refs(si, NULL, NULL);
1599                 if (!si->nr_ours && !si->nr_theirs) {
1600                         oid_array_clear(&ref);
1601                         return;
1602                 }
1603                 for (i = 0; i < si->nr_ours; i++)
1604                         oid_array_append(&extra, &oid[si->ours[i]]);
1605                 for (i = 0; i < si->nr_theirs; i++)
1606                         oid_array_append(&extra, &oid[si->theirs[i]]);
1607                 setup_alternate_shallow(&shallow_lock,
1608                                         &alternate_shallow_file,
1609                                         &extra);
1610                 commit_lock_file(&shallow_lock);
1611                 oid_array_clear(&extra);
1612                 oid_array_clear(&ref);
1613                 alternate_shallow_file = NULL;
1614                 return;
1615         }
1616
1617         /*
1618          * remote is also shallow, check what ref is safe to update
1619          * without updating .git/shallow
1620          */
1621         status = xcalloc(nr_sought, sizeof(*status));
1622         assign_shallow_commits_to_refs(si, NULL, status);
1623         if (si->nr_ours || si->nr_theirs) {
1624                 for (i = 0; i < nr_sought; i++)
1625                         if (status[i])
1626                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1627         }
1628         free(status);
1629         oid_array_clear(&ref);
1630 }
1631
1632 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1633 {
1634         struct ref **rm = cb_data;
1635         struct ref *ref = *rm;
1636
1637         if (!ref)
1638                 return -1; /* end of the list */
1639         *rm = ref->next;
1640         oidcpy(oid, &ref->old_oid);
1641         return 0;
1642 }
1643
1644 struct ref *fetch_pack(struct fetch_pack_args *args,
1645                        int fd[],
1646                        const struct ref *ref,
1647                        struct ref **sought, int nr_sought,
1648                        struct oid_array *shallow,
1649                        char **pack_lockfile,
1650                        enum protocol_version version)
1651 {
1652         struct ref *ref_cpy;
1653         struct shallow_info si;
1654         struct oid_array shallows_scratch = OID_ARRAY_INIT;
1655
1656         fetch_pack_setup();
1657         if (nr_sought)
1658                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1659
1660         if (args->no_dependents && !args->filter_options.choice) {
1661                 /*
1662                  * The protocol does not support requesting that only the
1663                  * wanted objects be sent, so approximate this by setting a
1664                  * "blob:none" filter if no filter is already set. This works
1665                  * for all object types: note that wanted blobs will still be
1666                  * sent because they are directly specified as a "want".
1667                  *
1668                  * NEEDSWORK: Add an option in the protocol to request that
1669                  * only the wanted objects be sent, and implement it.
1670                  */
1671                 parse_list_objects_filter(&args->filter_options, "blob:none");
1672         }
1673
1674         if (version != protocol_v2 && !ref) {
1675                 packet_flush(fd[1]);
1676                 die(_("no matching remote head"));
1677         }
1678         if (version == protocol_v2) {
1679                 if (shallow->nr)
1680                         BUG("Protocol V2 does not provide shallows at this point in the fetch");
1681                 memset(&si, 0, sizeof(si));
1682                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1683                                            &shallows_scratch, &si,
1684                                            pack_lockfile);
1685         } else {
1686                 prepare_shallow_info(&si, shallow);
1687                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1688                                         &si, pack_lockfile);
1689         }
1690         reprepare_packed_git(the_repository);
1691
1692         if (!args->cloning && args->deepen) {
1693                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1694                 struct ref *iterator = ref_cpy;
1695                 opt.shallow_file = alternate_shallow_file;
1696                 if (args->deepen)
1697                         opt.is_deepening_fetch = 1;
1698                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1699                         error(_("remote did not send all necessary objects"));
1700                         free_refs(ref_cpy);
1701                         ref_cpy = NULL;
1702                         rollback_lock_file(&shallow_lock);
1703                         goto cleanup;
1704                 }
1705                 args->connectivity_checked = 1;
1706         }
1707
1708         update_shallow(args, sought, nr_sought, &si);
1709 cleanup:
1710         clear_shallow_info(&si);
1711         oid_array_clear(&shallows_scratch);
1712         return ref_cpy;
1713 }
1714
1715 int report_unmatched_refs(struct ref **sought, int nr_sought)
1716 {
1717         int i, ret = 0;
1718
1719         for (i = 0; i < nr_sought; i++) {
1720                 if (!sought[i])
1721                         continue;
1722                 switch (sought[i]->match_status) {
1723                 case REF_MATCHED:
1724                         continue;
1725                 case REF_NOT_MATCHED:
1726                         error(_("no such remote ref %s"), sought[i]->name);
1727                         break;
1728                 case REF_UNADVERTISED_NOT_ALLOWED:
1729                         error(_("Server does not allow request for unadvertised object %s"),
1730                               sought[i]->name);
1731                         break;
1732                 }
1733                 ret = 1;
1734         }
1735         return ret;
1736 }