object-store: migrate alternates struct and functions from cache.h
[git] / bundle.c
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "bundle.h"
4 #include "object.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "list-objects.h"
9 #include "run-command.h"
10 #include "refs.h"
11 #include "argv-array.h"
12
13 static const char bundle_signature[] = "# v2 git bundle\n";
14
15 static void add_to_ref_list(const struct object_id *oid, const char *name,
16                 struct ref_list *list)
17 {
18         ALLOC_GROW(list->list, list->nr + 1, list->alloc);
19         oidcpy(&list->list[list->nr].oid, oid);
20         list->list[list->nr].name = xstrdup(name);
21         list->nr++;
22 }
23
24 static int parse_bundle_header(int fd, struct bundle_header *header,
25                                const char *report_path)
26 {
27         struct strbuf buf = STRBUF_INIT;
28         int status = 0;
29
30         /* The bundle header begins with the signature */
31         if (strbuf_getwholeline_fd(&buf, fd, '\n') ||
32             strcmp(buf.buf, bundle_signature)) {
33                 if (report_path)
34                         error(_("'%s' does not look like a v2 bundle file"),
35                               report_path);
36                 status = -1;
37                 goto abort;
38         }
39
40         /* The bundle header ends with an empty line */
41         while (!strbuf_getwholeline_fd(&buf, fd, '\n') &&
42                buf.len && buf.buf[0] != '\n') {
43                 struct object_id oid;
44                 int is_prereq = 0;
45                 const char *p;
46
47                 if (*buf.buf == '-') {
48                         is_prereq = 1;
49                         strbuf_remove(&buf, 0, 1);
50                 }
51                 strbuf_rtrim(&buf);
52
53                 /*
54                  * Tip lines have object name, SP, and refname.
55                  * Prerequisites have object name that is optionally
56                  * followed by SP and subject line.
57                  */
58                 if (parse_oid_hex(buf.buf, &oid, &p) ||
59                     (*p && !isspace(*p)) ||
60                     (!is_prereq && !*p)) {
61                         if (report_path)
62                                 error(_("unrecognized header: %s%s (%d)"),
63                                       (is_prereq ? "-" : ""), buf.buf, (int)buf.len);
64                         status = -1;
65                         break;
66                 } else {
67                         if (is_prereq)
68                                 add_to_ref_list(&oid, "", &header->prerequisites);
69                         else
70                                 add_to_ref_list(&oid, p + 1, &header->references);
71                 }
72         }
73
74  abort:
75         if (status) {
76                 close(fd);
77                 fd = -1;
78         }
79         strbuf_release(&buf);
80         return fd;
81 }
82
83 int read_bundle_header(const char *path, struct bundle_header *header)
84 {
85         int fd = open(path, O_RDONLY);
86
87         if (fd < 0)
88                 return error(_("could not open '%s'"), path);
89         return parse_bundle_header(fd, header, path);
90 }
91
92 int is_bundle(const char *path, int quiet)
93 {
94         struct bundle_header header;
95         int fd = open(path, O_RDONLY);
96
97         if (fd < 0)
98                 return 0;
99         memset(&header, 0, sizeof(header));
100         fd = parse_bundle_header(fd, &header, quiet ? NULL : path);
101         if (fd >= 0)
102                 close(fd);
103         return (fd >= 0);
104 }
105
106 static int list_refs(struct ref_list *r, int argc, const char **argv)
107 {
108         int i;
109
110         for (i = 0; i < r->nr; i++) {
111                 if (argc > 1) {
112                         int j;
113                         for (j = 1; j < argc; j++)
114                                 if (!strcmp(r->list[i].name, argv[j]))
115                                         break;
116                         if (j == argc)
117                                 continue;
118                 }
119                 printf("%s %s\n", oid_to_hex(&r->list[i].oid),
120                                 r->list[i].name);
121         }
122         return 0;
123 }
124
125 /* Remember to update object flag allocation in object.h */
126 #define PREREQ_MARK (1u<<16)
127
128 int verify_bundle(struct bundle_header *header, int verbose)
129 {
130         /*
131          * Do fast check, then if any prereqs are missing then go line by line
132          * to be verbose about the errors
133          */
134         struct ref_list *p = &header->prerequisites;
135         struct rev_info revs;
136         const char *argv[] = {NULL, "--all", NULL};
137         struct commit *commit;
138         int i, ret = 0, req_nr;
139         const char *message = _("Repository lacks these prerequisite commits:");
140
141         init_revisions(&revs, NULL);
142         for (i = 0; i < p->nr; i++) {
143                 struct ref_list_entry *e = p->list + i;
144                 struct object *o = parse_object(&e->oid);
145                 if (o) {
146                         o->flags |= PREREQ_MARK;
147                         add_pending_object(&revs, o, e->name);
148                         continue;
149                 }
150                 if (++ret == 1)
151                         error("%s", message);
152                 error("%s %s", oid_to_hex(&e->oid), e->name);
153         }
154         if (revs.pending.nr != p->nr)
155                 return ret;
156         req_nr = revs.pending.nr;
157         setup_revisions(2, argv, &revs, NULL);
158
159         if (prepare_revision_walk(&revs))
160                 die(_("revision walk setup failed"));
161
162         i = req_nr;
163         while (i && (commit = get_revision(&revs)))
164                 if (commit->object.flags & PREREQ_MARK)
165                         i--;
166
167         for (i = 0; i < p->nr; i++) {
168                 struct ref_list_entry *e = p->list + i;
169                 struct object *o = parse_object(&e->oid);
170                 assert(o); /* otherwise we'd have returned early */
171                 if (o->flags & SHOWN)
172                         continue;
173                 if (++ret == 1)
174                         error("%s", message);
175                 error("%s %s", oid_to_hex(&e->oid), e->name);
176         }
177
178         /* Clean up objects used, as they will be reused. */
179         for (i = 0; i < p->nr; i++) {
180                 struct ref_list_entry *e = p->list + i;
181                 commit = lookup_commit_reference_gently(&e->oid, 1);
182                 if (commit)
183                         clear_commit_marks(commit, ALL_REV_FLAGS);
184         }
185
186         if (verbose) {
187                 struct ref_list *r;
188
189                 r = &header->references;
190                 printf_ln(Q_("The bundle contains this ref:",
191                              "The bundle contains these %d refs:",
192                              r->nr),
193                           r->nr);
194                 list_refs(r, 0, NULL);
195                 r = &header->prerequisites;
196                 if (!r->nr) {
197                         printf_ln(_("The bundle records a complete history."));
198                 } else {
199                         printf_ln(Q_("The bundle requires this ref:",
200                                      "The bundle requires these %d refs:",
201                                      r->nr),
202                                   r->nr);
203                         list_refs(r, 0, NULL);
204                 }
205         }
206         return ret;
207 }
208
209 int list_bundle_refs(struct bundle_header *header, int argc, const char **argv)
210 {
211         return list_refs(&header->references, argc, argv);
212 }
213
214 static int is_tag_in_date_range(struct object *tag, struct rev_info *revs)
215 {
216         unsigned long size;
217         enum object_type type;
218         char *buf = NULL, *line, *lineend;
219         timestamp_t date;
220         int result = 1;
221
222         if (revs->max_age == -1 && revs->min_age == -1)
223                 goto out;
224
225         buf = read_sha1_file(tag->oid.hash, &type, &size);
226         if (!buf)
227                 goto out;
228         line = memmem(buf, size, "\ntagger ", 8);
229         if (!line++)
230                 goto out;
231         lineend = memchr(line, '\n', buf + size - line);
232         line = memchr(line, '>', lineend ? lineend - line : buf + size - line);
233         if (!line++)
234                 goto out;
235         date = parse_timestamp(line, NULL, 10);
236         result = (revs->max_age == -1 || revs->max_age < date) &&
237                 (revs->min_age == -1 || revs->min_age > date);
238 out:
239         free(buf);
240         return result;
241 }
242
243
244 /* Write the pack data to bundle_fd, then close it if it is > 1. */
245 static int write_pack_data(int bundle_fd, struct rev_info *revs)
246 {
247         struct child_process pack_objects = CHILD_PROCESS_INIT;
248         int i;
249
250         argv_array_pushl(&pack_objects.args,
251                          "pack-objects", "--all-progress-implied",
252                          "--stdout", "--thin", "--delta-base-offset",
253                          NULL);
254         pack_objects.in = -1;
255         pack_objects.out = bundle_fd;
256         pack_objects.git_cmd = 1;
257         if (start_command(&pack_objects))
258                 return error(_("Could not spawn pack-objects"));
259
260         for (i = 0; i < revs->pending.nr; i++) {
261                 struct object *object = revs->pending.objects[i].item;
262                 if (object->flags & UNINTERESTING)
263                         write_or_die(pack_objects.in, "^", 1);
264                 write_or_die(pack_objects.in, oid_to_hex(&object->oid), GIT_SHA1_HEXSZ);
265                 write_or_die(pack_objects.in, "\n", 1);
266         }
267         close(pack_objects.in);
268         if (finish_command(&pack_objects))
269                 return error(_("pack-objects died"));
270         return 0;
271 }
272
273 static int compute_and_write_prerequisites(int bundle_fd,
274                                            struct rev_info *revs,
275                                            int argc, const char **argv)
276 {
277         struct child_process rls = CHILD_PROCESS_INIT;
278         struct strbuf buf = STRBUF_INIT;
279         FILE *rls_fout;
280         int i;
281
282         argv_array_pushl(&rls.args,
283                          "rev-list", "--boundary", "--pretty=oneline",
284                          NULL);
285         for (i = 1; i < argc; i++)
286                 argv_array_push(&rls.args, argv[i]);
287         rls.out = -1;
288         rls.git_cmd = 1;
289         if (start_command(&rls))
290                 return -1;
291         rls_fout = xfdopen(rls.out, "r");
292         while (strbuf_getwholeline(&buf, rls_fout, '\n') != EOF) {
293                 struct object_id oid;
294                 if (buf.len > 0 && buf.buf[0] == '-') {
295                         write_or_die(bundle_fd, buf.buf, buf.len);
296                         if (!get_oid_hex(buf.buf + 1, &oid)) {
297                                 struct object *object = parse_object_or_die(&oid,
298                                                                             buf.buf);
299                                 object->flags |= UNINTERESTING;
300                                 add_pending_object(revs, object, buf.buf);
301                         }
302                 } else if (!get_oid_hex(buf.buf, &oid)) {
303                         struct object *object = parse_object_or_die(&oid,
304                                                                     buf.buf);
305                         object->flags |= SHOWN;
306                 }
307         }
308         strbuf_release(&buf);
309         fclose(rls_fout);
310         if (finish_command(&rls))
311                 return error(_("rev-list died"));
312         return 0;
313 }
314
315 /*
316  * Write out bundle refs based on the tips already
317  * parsed into revs.pending. As a side effect, may
318  * manipulate revs.pending to include additional
319  * necessary objects (like tags).
320  *
321  * Returns the number of refs written, or negative
322  * on error.
323  */
324 static int write_bundle_refs(int bundle_fd, struct rev_info *revs)
325 {
326         int i;
327         int ref_count = 0;
328
329         for (i = 0; i < revs->pending.nr; i++) {
330                 struct object_array_entry *e = revs->pending.objects + i;
331                 struct object_id oid;
332                 char *ref;
333                 const char *display_ref;
334                 int flag;
335
336                 if (e->item->flags & UNINTERESTING)
337                         continue;
338                 if (dwim_ref(e->name, strlen(e->name), &oid, &ref) != 1)
339                         goto skip_write_ref;
340                 if (read_ref_full(e->name, RESOLVE_REF_READING, &oid, &flag))
341                         flag = 0;
342                 display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
343
344                 if (e->item->type == OBJ_TAG &&
345                                 !is_tag_in_date_range(e->item, revs)) {
346                         e->item->flags |= UNINTERESTING;
347                         goto skip_write_ref;
348                 }
349
350                 /*
351                  * Make sure the refs we wrote out is correct; --max-count and
352                  * other limiting options could have prevented all the tips
353                  * from getting output.
354                  *
355                  * Non commit objects such as tags and blobs do not have
356                  * this issue as they are not affected by those extra
357                  * constraints.
358                  */
359                 if (!(e->item->flags & SHOWN) && e->item->type == OBJ_COMMIT) {
360                         warning(_("ref '%s' is excluded by the rev-list options"),
361                                 e->name);
362                         goto skip_write_ref;
363                 }
364                 /*
365                  * If you run "git bundle create bndl v1.0..v2.0", the
366                  * name of the positive ref is "v2.0" but that is the
367                  * commit that is referenced by the tag, and not the tag
368                  * itself.
369                  */
370                 if (oidcmp(&oid, &e->item->oid)) {
371                         /*
372                          * Is this the positive end of a range expressed
373                          * in terms of a tag (e.g. v2.0 from the range
374                          * "v1.0..v2.0")?
375                          */
376                         struct commit *one = lookup_commit_reference(&oid);
377                         struct object *obj;
378
379                         if (e->item == &(one->object)) {
380                                 /*
381                                  * Need to include e->name as an
382                                  * independent ref to the pack-objects
383                                  * input, so that the tag is included
384                                  * in the output; otherwise we would
385                                  * end up triggering "empty bundle"
386                                  * error.
387                                  */
388                                 obj = parse_object_or_die(&oid, e->name);
389                                 obj->flags |= SHOWN;
390                                 add_pending_object(revs, obj, e->name);
391                         }
392                         goto skip_write_ref;
393                 }
394
395                 ref_count++;
396                 write_or_die(bundle_fd, oid_to_hex(&e->item->oid), 40);
397                 write_or_die(bundle_fd, " ", 1);
398                 write_or_die(bundle_fd, display_ref, strlen(display_ref));
399                 write_or_die(bundle_fd, "\n", 1);
400  skip_write_ref:
401                 free(ref);
402         }
403
404         /* end header */
405         write_or_die(bundle_fd, "\n", 1);
406         return ref_count;
407 }
408
409 int create_bundle(struct bundle_header *header, const char *path,
410                   int argc, const char **argv)
411 {
412         static struct lock_file lock;
413         int bundle_fd = -1;
414         int bundle_to_stdout;
415         int ref_count = 0;
416         struct rev_info revs;
417
418         bundle_to_stdout = !strcmp(path, "-");
419         if (bundle_to_stdout)
420                 bundle_fd = 1;
421         else {
422                 bundle_fd = hold_lock_file_for_update(&lock, path,
423                                                       LOCK_DIE_ON_ERROR);
424
425                 /*
426                  * write_pack_data() will close the fd passed to it,
427                  * but commit_lock_file() will also try to close the
428                  * lockfile's fd. So make a copy of the file
429                  * descriptor to avoid trying to close it twice.
430                  */
431                 bundle_fd = dup(bundle_fd);
432                 if (bundle_fd < 0)
433                         die_errno("unable to dup file descriptor");
434         }
435
436         /* write signature */
437         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
438
439         /* init revs to list objects for pack-objects later */
440         save_commit_buffer = 0;
441         init_revisions(&revs, NULL);
442
443         /* write prerequisites */
444         if (compute_and_write_prerequisites(bundle_fd, &revs, argc, argv))
445                 goto err;
446
447         argc = setup_revisions(argc, argv, &revs, NULL);
448
449         if (argc > 1) {
450                 error(_("unrecognized argument: %s"), argv[1]);
451                 goto err;
452         }
453
454         object_array_remove_duplicates(&revs.pending);
455
456         ref_count = write_bundle_refs(bundle_fd, &revs);
457         if (!ref_count)
458                 die(_("Refusing to create empty bundle."));
459         else if (ref_count < 0)
460                 goto err;
461
462         /* write pack */
463         if (write_pack_data(bundle_fd, &revs)) {
464                 bundle_fd = -1; /* already closed by the above call */
465                 goto err;
466         }
467
468         if (!bundle_to_stdout) {
469                 if (commit_lock_file(&lock))
470                         die_errno(_("cannot create '%s'"), path);
471         }
472         return 0;
473 err:
474         if (!bundle_to_stdout) {
475                 if (0 <= bundle_fd)
476                         close(bundle_fd);
477                 rollback_lock_file(&lock);
478         }
479         return -1;
480 }
481
482 int unbundle(struct bundle_header *header, int bundle_fd, int flags)
483 {
484         const char *argv_index_pack[] = {"index-pack",
485                                          "--fix-thin", "--stdin", NULL, NULL};
486         struct child_process ip = CHILD_PROCESS_INIT;
487
488         if (flags & BUNDLE_VERBOSE)
489                 argv_index_pack[3] = "-v";
490
491         if (verify_bundle(header, 0))
492                 return -1;
493         ip.argv = argv_index_pack;
494         ip.in = bundle_fd;
495         ip.no_stdout = 1;
496         ip.git_cmd = 1;
497         if (run_command(&ip))
498                 return error(_("index-pack died"));
499         return 0;
500 }