bundle: add parse_bundle_header() helper function
[git] / bundle.c
1 #include "cache.h"
2 #include "bundle.h"
3 #include "object.h"
4 #include "commit.h"
5 #include "diff.h"
6 #include "revision.h"
7 #include "list-objects.h"
8 #include "run-command.h"
9 #include "refs.h"
10
11 static const char bundle_signature[] = "# v2 git bundle\n";
12
13 static void add_to_ref_list(const unsigned char *sha1, const char *name,
14                 struct ref_list *list)
15 {
16         if (list->nr + 1 >= list->alloc) {
17                 list->alloc = alloc_nr(list->nr + 1);
18                 list->list = xrealloc(list->list,
19                                 list->alloc * sizeof(list->list[0]));
20         }
21         memcpy(list->list[list->nr].sha1, sha1, 20);
22         list->list[list->nr].name = xstrdup(name);
23         list->nr++;
24 }
25
26 /* Eventually this should go to strbuf.[ch] */
27 static int strbuf_readline_fd(struct strbuf *sb, int fd)
28 {
29         strbuf_reset(sb);
30
31         while (1) {
32                 char ch;
33                 ssize_t len = xread(fd, &ch, 1);
34                 if (len < 0)
35                         return -1;
36                 strbuf_addch(sb, ch);
37                 if (ch == '\n')
38                         break;
39         }
40         return 0;
41 }
42
43 static int parse_bundle_header(int fd, struct bundle_header *header,
44                                const char *report_path)
45 {
46         struct strbuf buf = STRBUF_INIT;
47         int status = 0;
48
49         /* The bundle header begins with the signature */
50         if (strbuf_readline_fd(&buf, fd) ||
51             strcmp(buf.buf, bundle_signature)) {
52                 if (report_path)
53                         error("'%s' does not look like a v2 bundle file",
54                               report_path);
55                 status = -1;
56                 goto abort;
57         }
58
59         /* The bundle header ends with an empty line */
60         while (!strbuf_readline_fd(&buf, fd) &&
61                buf.len && buf.buf[0] != '\n') {
62                 unsigned char sha1[20];
63                 int is_prereq = 0;
64
65                 if (*buf.buf == '-') {
66                         is_prereq = 1;
67                         strbuf_remove(&buf, 0, 1);
68                 }
69                 strbuf_rtrim(&buf);
70
71                 /*
72                  * Tip lines have object name, SP, and refname.
73                  * Prerequisites have object name that is optionally
74                  * followed by SP and subject line.
75                  */
76                 if (get_sha1_hex(buf.buf, sha1) ||
77                     (40 <= buf.len && !isspace(buf.buf[40])) ||
78                     (!is_prereq && buf.len <= 40)) {
79                         if (report_path)
80                                 error("unrecognized header: %s%s (%d)",
81                                       (is_prereq ? "-" : ""), buf.buf, (int)buf.len);
82                         status = -1;
83                         break;
84                 } else {
85                         if (is_prereq)
86                                 add_to_ref_list(sha1, "", &header->prerequisites);
87                         else
88                                 add_to_ref_list(sha1, buf.buf + 41, &header->references);
89                 }
90         }
91
92  abort:
93         if (status) {
94                 close(fd);
95                 fd = -1;
96         }
97         strbuf_release(&buf);
98         return fd;
99 }
100
101 int read_bundle_header(const char *path, struct bundle_header *header)
102 {
103         int fd = open(path, O_RDONLY);
104
105         if (fd < 0)
106                 return error("could not open '%s'", path);
107         return parse_bundle_header(fd, header, path);
108 }
109
110 int is_bundle(const char *path, int quiet)
111 {
112         struct bundle_header header;
113         int fd = open(path, O_RDONLY);
114
115         if (fd < 0)
116                 return 0;
117         memset(&header, 0, sizeof(header));
118         fd = parse_bundle_header(fd, &header, quiet ? NULL : path);
119         if (fd >= 0)
120                 close(fd);
121         return (fd >= 0);
122 }
123
124 static int list_refs(struct ref_list *r, int argc, const char **argv)
125 {
126         int i;
127
128         for (i = 0; i < r->nr; i++) {
129                 if (argc > 1) {
130                         int j;
131                         for (j = 1; j < argc; j++)
132                                 if (!strcmp(r->list[i].name, argv[j]))
133                                         break;
134                         if (j == argc)
135                                 continue;
136                 }
137                 printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
138                                 r->list[i].name);
139         }
140         return 0;
141 }
142
143 #define PREREQ_MARK (1u<<16)
144
145 int verify_bundle(struct bundle_header *header, int verbose)
146 {
147         /*
148          * Do fast check, then if any prereqs are missing then go line by line
149          * to be verbose about the errors
150          */
151         struct ref_list *p = &header->prerequisites;
152         struct rev_info revs;
153         const char *argv[] = {NULL, "--all", NULL};
154         struct object_array refs;
155         struct commit *commit;
156         int i, ret = 0, req_nr;
157         const char *message = "Repository lacks these prerequisite commits:";
158
159         init_revisions(&revs, NULL);
160         for (i = 0; i < p->nr; i++) {
161                 struct ref_list_entry *e = p->list + i;
162                 struct object *o = parse_object(e->sha1);
163                 if (o) {
164                         o->flags |= PREREQ_MARK;
165                         add_pending_object(&revs, o, e->name);
166                         continue;
167                 }
168                 if (++ret == 1)
169                         error("%s", message);
170                 error("%s %s", sha1_to_hex(e->sha1), e->name);
171         }
172         if (revs.pending.nr != p->nr)
173                 return ret;
174         req_nr = revs.pending.nr;
175         setup_revisions(2, argv, &revs, NULL);
176
177         memset(&refs, 0, sizeof(struct object_array));
178         for (i = 0; i < revs.pending.nr; i++) {
179                 struct object_array_entry *e = revs.pending.objects + i;
180                 add_object_array(e->item, e->name, &refs);
181         }
182
183         if (prepare_revision_walk(&revs))
184                 die("revision walk setup failed");
185
186         i = req_nr;
187         while (i && (commit = get_revision(&revs)))
188                 if (commit->object.flags & PREREQ_MARK)
189                         i--;
190
191         for (i = 0; i < req_nr; i++)
192                 if (!(refs.objects[i].item->flags & SHOWN)) {
193                         if (++ret == 1)
194                                 error("%s", message);
195                         error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
196                                 refs.objects[i].name);
197                 }
198
199         for (i = 0; i < refs.nr; i++)
200                 clear_commit_marks((struct commit *)refs.objects[i].item, -1);
201
202         if (verbose) {
203                 struct ref_list *r;
204
205                 r = &header->references;
206                 printf("The bundle contains %d ref%s\n",
207                        r->nr, (1 < r->nr) ? "s" : "");
208                 list_refs(r, 0, NULL);
209                 r = &header->prerequisites;
210                 printf("The bundle requires these %d ref%s\n",
211                        r->nr, (1 < r->nr) ? "s" : "");
212                 list_refs(r, 0, NULL);
213         }
214         return ret;
215 }
216
217 int list_bundle_refs(struct bundle_header *header, int argc, const char **argv)
218 {
219         return list_refs(&header->references, argc, argv);
220 }
221
222 static int is_tag_in_date_range(struct object *tag, struct rev_info *revs)
223 {
224         unsigned long size;
225         enum object_type type;
226         char *buf, *line, *lineend;
227         unsigned long date;
228
229         if (revs->max_age == -1 && revs->min_age == -1)
230                 return 1;
231
232         buf = read_sha1_file(tag->sha1, &type, &size);
233         if (!buf)
234                 return 1;
235         line = memmem(buf, size, "\ntagger ", 8);
236         if (!line++)
237                 return 1;
238         lineend = memchr(line, buf + size - line, '\n');
239         line = memchr(line, lineend ? lineend - line : buf + size - line, '>');
240         if (!line++)
241                 return 1;
242         date = strtoul(line, NULL, 10);
243         free(buf);
244         return (revs->max_age == -1 || revs->max_age < date) &&
245                 (revs->min_age == -1 || revs->min_age > date);
246 }
247
248 int create_bundle(struct bundle_header *header, const char *path,
249                 int argc, const char **argv)
250 {
251         static struct lock_file lock;
252         int bundle_fd = -1;
253         int bundle_to_stdout;
254         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
255         const char **argv_pack = xmalloc(6 * sizeof(const char *));
256         int i, ref_count = 0;
257         char buffer[1024];
258         struct rev_info revs;
259         struct child_process rls;
260         FILE *rls_fout;
261
262         bundle_to_stdout = !strcmp(path, "-");
263         if (bundle_to_stdout)
264                 bundle_fd = 1;
265         else
266                 bundle_fd = hold_lock_file_for_update(&lock, path,
267                                                       LOCK_DIE_ON_ERROR);
268
269         /* write signature */
270         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
271
272         /* init revs to list objects for pack-objects later */
273         save_commit_buffer = 0;
274         init_revisions(&revs, NULL);
275
276         /* write prerequisites */
277         memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
278         argv_boundary[0] = "rev-list";
279         argv_boundary[1] = "--boundary";
280         argv_boundary[2] = "--pretty=oneline";
281         argv_boundary[argc + 2] = NULL;
282         memset(&rls, 0, sizeof(rls));
283         rls.argv = argv_boundary;
284         rls.out = -1;
285         rls.git_cmd = 1;
286         if (start_command(&rls))
287                 return -1;
288         rls_fout = xfdopen(rls.out, "r");
289         while (fgets(buffer, sizeof(buffer), rls_fout)) {
290                 unsigned char sha1[20];
291                 if (buffer[0] == '-') {
292                         write_or_die(bundle_fd, buffer, strlen(buffer));
293                         if (!get_sha1_hex(buffer + 1, sha1)) {
294                                 struct object *object = parse_object(sha1);
295                                 object->flags |= UNINTERESTING;
296                                 add_pending_object(&revs, object, buffer);
297                         }
298                 } else if (!get_sha1_hex(buffer, sha1)) {
299                         struct object *object = parse_object(sha1);
300                         object->flags |= SHOWN;
301                 }
302         }
303         fclose(rls_fout);
304         if (finish_command(&rls))
305                 return error("rev-list died");
306
307         /* write references */
308         argc = setup_revisions(argc, argv, &revs, NULL);
309
310         if (argc > 1)
311                 return error("unrecognized argument: %s'", argv[1]);
312
313         object_array_remove_duplicates(&revs.pending);
314
315         for (i = 0; i < revs.pending.nr; i++) {
316                 struct object_array_entry *e = revs.pending.objects + i;
317                 unsigned char sha1[20];
318                 char *ref;
319                 const char *display_ref;
320                 int flag;
321
322                 if (e->item->flags & UNINTERESTING)
323                         continue;
324                 if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
325                         continue;
326                 if (!resolve_ref(e->name, sha1, 1, &flag))
327                         flag = 0;
328                 display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
329
330                 if (e->item->type == OBJ_TAG &&
331                                 !is_tag_in_date_range(e->item, &revs)) {
332                         e->item->flags |= UNINTERESTING;
333                         continue;
334                 }
335
336                 /*
337                  * Make sure the refs we wrote out is correct; --max-count and
338                  * other limiting options could have prevented all the tips
339                  * from getting output.
340                  *
341                  * Non commit objects such as tags and blobs do not have
342                  * this issue as they are not affected by those extra
343                  * constraints.
344                  */
345                 if (!(e->item->flags & SHOWN) && e->item->type == OBJ_COMMIT) {
346                         warning("ref '%s' is excluded by the rev-list options",
347                                 e->name);
348                         free(ref);
349                         continue;
350                 }
351                 /*
352                  * If you run "git bundle create bndl v1.0..v2.0", the
353                  * name of the positive ref is "v2.0" but that is the
354                  * commit that is referenced by the tag, and not the tag
355                  * itself.
356                  */
357                 if (hashcmp(sha1, e->item->sha1)) {
358                         /*
359                          * Is this the positive end of a range expressed
360                          * in terms of a tag (e.g. v2.0 from the range
361                          * "v1.0..v2.0")?
362                          */
363                         struct commit *one = lookup_commit_reference(sha1);
364                         struct object *obj;
365
366                         if (e->item == &(one->object)) {
367                                 /*
368                                  * Need to include e->name as an
369                                  * independent ref to the pack-objects
370                                  * input, so that the tag is included
371                                  * in the output; otherwise we would
372                                  * end up triggering "empty bundle"
373                                  * error.
374                                  */
375                                 obj = parse_object(sha1);
376                                 obj->flags |= SHOWN;
377                                 add_pending_object(&revs, obj, e->name);
378                         }
379                         free(ref);
380                         continue;
381                 }
382
383                 ref_count++;
384                 write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
385                 write_or_die(bundle_fd, " ", 1);
386                 write_or_die(bundle_fd, display_ref, strlen(display_ref));
387                 write_or_die(bundle_fd, "\n", 1);
388                 free(ref);
389         }
390         if (!ref_count)
391                 die ("Refusing to create empty bundle.");
392
393         /* end header */
394         write_or_die(bundle_fd, "\n", 1);
395
396         /* write pack */
397         argv_pack[0] = "pack-objects";
398         argv_pack[1] = "--all-progress-implied";
399         argv_pack[2] = "--stdout";
400         argv_pack[3] = "--thin";
401         argv_pack[4] = "--delta-base-offset";
402         argv_pack[5] = NULL;
403         memset(&rls, 0, sizeof(rls));
404         rls.argv = argv_pack;
405         rls.in = -1;
406         rls.out = bundle_fd;
407         rls.git_cmd = 1;
408         if (start_command(&rls))
409                 return error("Could not spawn pack-objects");
410
411         /*
412          * start_command closed bundle_fd if it was > 1
413          * so set the lock fd to -1 so commit_lock_file()
414          * won't fail trying to close it.
415          */
416         lock.fd = -1;
417
418         for (i = 0; i < revs.pending.nr; i++) {
419                 struct object *object = revs.pending.objects[i].item;
420                 if (object->flags & UNINTERESTING)
421                         write_or_die(rls.in, "^", 1);
422                 write_or_die(rls.in, sha1_to_hex(object->sha1), 40);
423                 write_or_die(rls.in, "\n", 1);
424         }
425         close(rls.in);
426         if (finish_command(&rls))
427                 return error ("pack-objects died");
428         if (!bundle_to_stdout) {
429                 if (commit_lock_file(&lock))
430                         die_errno("cannot create '%s'", path);
431         }
432         return 0;
433 }
434
435 int unbundle(struct bundle_header *header, int bundle_fd)
436 {
437         const char *argv_index_pack[] = {"index-pack",
438                 "--fix-thin", "--stdin", NULL};
439         struct child_process ip;
440
441         if (verify_bundle(header, 0))
442                 return -1;
443         memset(&ip, 0, sizeof(ip));
444         ip.argv = argv_index_pack;
445         ip.in = bundle_fd;
446         ip.no_stdout = 1;
447         ip.git_cmd = 1;
448         if (run_command(&ip))
449                 return error("index-pack died");
450         return 0;
451 }