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