Merge branch 'maint'
[git] / send-pack.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "tag.h"
4 #include "refs.h"
5 #include "pkt-line.h"
6 #include "exec_cmd.h"
7
8 static const char send_pack_usage[] =
9 "git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
10 "  --all and explicit <head> specification are mutually exclusive.";
11 static const char *exec = "git-receive-pack";
12 static int verbose;
13 static int send_all;
14 static int force_update;
15 static int use_thin_pack;
16
17 static int is_zero_sha1(const unsigned char *sha1)
18 {
19         int i;
20
21         for (i = 0; i < 20; i++) {
22                 if (*sha1++)
23                         return 0;
24         }
25         return 1;
26 }
27
28 static void exec_pack_objects(void)
29 {
30         static const char *args[] = {
31                 "pack-objects",
32                 "--all-progress",
33                 "--stdout",
34                 NULL
35         };
36         execv_git_cmd(args);
37         die("git-pack-objects exec failed (%s)", strerror(errno));
38 }
39
40 static void exec_rev_list(struct ref *refs)
41 {
42         static const char *args[4];
43         int i = 0;
44
45         args[i++] = "rev-list"; /* 0 */
46         if (use_thin_pack)      /* 1 */
47                 args[i++] = "--objects-edge";
48         else
49                 args[i++] = "--objects";
50
51         args[i++] = "--stdin";
52
53         args[i] = NULL;
54         execv_git_cmd(args);
55         die("git-rev-list exec failed (%s)", strerror(errno));
56 }
57
58 /*
59  * Run "rev-list --stdin | pack-objects" pipe.
60  */
61 static void rev_list(int fd, struct ref *refs)
62 {
63         int pipe_fd[2];
64         pid_t pack_objects_pid;
65
66         if (pipe(pipe_fd) < 0)
67                 die("rev-list setup: pipe failed");
68         pack_objects_pid = fork();
69         if (!pack_objects_pid) {
70                 /* The child becomes pack-objects; reads from pipe
71                  * and writes to the original fd
72                  */
73                 dup2(pipe_fd[0], 0);
74                 dup2(fd, 1);
75                 close(pipe_fd[0]);
76                 close(pipe_fd[1]);
77                 close(fd);
78                 exec_pack_objects();
79                 die("pack-objects setup failed");
80         }
81         if (pack_objects_pid < 0)
82                 die("pack-objects fork failed");
83
84         /* We become rev-list --stdin; output goes to pipe. */
85         dup2(pipe_fd[1], 1);
86         close(pipe_fd[0]);
87         close(pipe_fd[1]);
88         close(fd);
89         exec_rev_list(refs);
90 }
91
92 /*
93  * Create "rev-list --stdin | pack-objects" pipe and feed
94  * the refs into the pipeline.
95  */
96 static void rev_list_generate(int fd, struct ref *refs)
97 {
98         int pipe_fd[2];
99         pid_t rev_list_generate_pid;
100
101         if (pipe(pipe_fd) < 0)
102                 die("rev-list-generate setup: pipe failed");
103         rev_list_generate_pid = fork();
104         if (!rev_list_generate_pid) {
105                 /* The child becomes the "rev-list | pack-objects"
106                  * pipeline.  It takes input from us, and its output
107                  * goes to fd.
108                  */
109                 dup2(pipe_fd[0], 0);
110                 dup2(fd, 1);
111                 close(pipe_fd[0]);
112                 close(pipe_fd[1]);
113                 close(fd);
114                 rev_list(fd, refs);
115                 die("rev-list setup failed");
116         }
117         if (rev_list_generate_pid < 0)
118                 die("rev-list-generate fork failed");
119
120         /* We feed the rev parameters to them.  We do not write into
121          * fd nor read from the pipe.
122          */
123         close(pipe_fd[0]);
124         close(fd);
125         while (refs) {
126                 char buf[42];
127
128                 if (!is_null_sha1(refs->old_sha1) &&
129                     has_sha1_file(refs->old_sha1)) {
130                         memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
131                         buf[0] = '^';
132                         buf[41] = '\n';
133                         write(pipe_fd[1], buf, 42);
134                 }
135                 if (!is_null_sha1(refs->new_sha1)) {
136                         memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
137                         buf[40] = '\n';
138                         write(pipe_fd[1], buf, 41);
139                 }
140                 refs = refs->next;
141         }
142         close(pipe_fd[1]);
143         // waitpid(rev_list_generate_pid);
144         exit(0);
145 }
146
147 /*
148  * Make a pack stream and spit it out into file descriptor fd
149  */
150 static void pack_objects(int fd, struct ref *refs)
151 {
152         pid_t rev_list_pid;
153
154         rev_list_pid = fork();
155         if (!rev_list_pid) {
156                 rev_list_generate(fd, refs);
157                 die("rev-list setup failed");
158         }
159         if (rev_list_pid < 0)
160                 die("rev-list fork failed");
161         /*
162          * We don't wait for the rev-list pipeline in the parent:
163          * we end up waiting for the other end instead
164          */
165 }
166
167 static void unmark_and_free(struct commit_list *list, unsigned int mark)
168 {
169         while (list) {
170                 struct commit_list *temp = list;
171                 temp->item->object.flags &= ~mark;
172                 list = temp->next;
173                 free(temp);
174         }
175 }
176
177 static int ref_newer(const unsigned char *new_sha1,
178                      const unsigned char *old_sha1)
179 {
180         struct object *o;
181         struct commit *old, *new;
182         struct commit_list *list, *used;
183         int found = 0;
184
185         /* Both new and old must be commit-ish and new is descendant of
186          * old.  Otherwise we require --force.
187          */
188         o = deref_tag(parse_object(old_sha1), NULL, 0);
189         if (!o || o->type != OBJ_COMMIT)
190                 return 0;
191         old = (struct commit *) o;
192
193         o = deref_tag(parse_object(new_sha1), NULL, 0);
194         if (!o || o->type != OBJ_COMMIT)
195                 return 0;
196         new = (struct commit *) o;
197
198         if (parse_commit(new) < 0)
199                 return 0;
200
201         used = list = NULL;
202         commit_list_insert(new, &list);
203         while (list) {
204                 new = pop_most_recent_commit(&list, 1);
205                 commit_list_insert(new, &used);
206                 if (new == old) {
207                         found = 1;
208                         break;
209                 }
210         }
211         unmark_and_free(list, 1);
212         unmark_and_free(used, 1);
213         return found;
214 }
215
216 static struct ref *local_refs, **local_tail;
217 static struct ref *remote_refs, **remote_tail;
218
219 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
220 {
221         struct ref *ref;
222         int len = strlen(refname) + 1;
223         ref = xcalloc(1, sizeof(*ref) + len);
224         hashcpy(ref->new_sha1, sha1);
225         memcpy(ref->name, refname, len);
226         *local_tail = ref;
227         local_tail = &ref->next;
228         return 0;
229 }
230
231 static void get_local_heads(void)
232 {
233         local_tail = &local_refs;
234         for_each_ref(one_local_ref, NULL);
235 }
236
237 static int receive_status(int in)
238 {
239         char line[1000];
240         int ret = 0;
241         int len = packet_read_line(in, line, sizeof(line));
242         if (len < 10 || memcmp(line, "unpack ", 7)) {
243                 fprintf(stderr, "did not receive status back\n");
244                 return -1;
245         }
246         if (memcmp(line, "unpack ok\n", 10)) {
247                 fputs(line, stderr);
248                 ret = -1;
249         }
250         while (1) {
251                 len = packet_read_line(in, line, sizeof(line));
252                 if (!len)
253                         break;
254                 if (len < 3 ||
255                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
256                         fprintf(stderr, "protocol error: %s\n", line);
257                         ret = -1;
258                         break;
259                 }
260                 if (!memcmp(line, "ok", 2))
261                         continue;
262                 fputs(line, stderr);
263                 ret = -1;
264         }
265         return ret;
266 }
267
268 static int send_pack(int in, int out, int nr_refspec, char **refspec)
269 {
270         struct ref *ref;
271         int new_refs;
272         int ret = 0;
273         int ask_for_status_report = 0;
274         int allow_deleting_refs = 0;
275         int expect_status_report = 0;
276
277         /* No funny business with the matcher */
278         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
279         get_local_heads();
280
281         /* Does the other end support the reporting? */
282         if (server_supports("report-status"))
283                 ask_for_status_report = 1;
284         if (server_supports("delete-refs"))
285                 allow_deleting_refs = 1;
286
287         /* match them up */
288         if (!remote_tail)
289                 remote_tail = &remote_refs;
290         if (match_refs(local_refs, remote_refs, &remote_tail,
291                        nr_refspec, refspec, send_all))
292                 return -1;
293
294         if (!remote_refs) {
295                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
296                 return 0;
297         }
298
299         /*
300          * Finally, tell the other end!
301          */
302         new_refs = 0;
303         for (ref = remote_refs; ref; ref = ref->next) {
304                 char old_hex[60], *new_hex;
305                 int delete_ref;
306
307                 if (!ref->peer_ref)
308                         continue;
309
310                 delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
311                 if (delete_ref && !allow_deleting_refs) {
312                         error("remote does not support deleting refs");
313                         ret = -2;
314                         continue;
315                 }
316                 if (!delete_ref &&
317                     !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
318                         if (verbose)
319                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
320                         continue;
321                 }
322
323                 /* This part determines what can overwrite what.
324                  * The rules are:
325                  *
326                  * (0) you can always use --force or +A:B notation to
327                  *     selectively force individual ref pairs.
328                  *
329                  * (1) if the old thing does not exist, it is OK.
330                  *
331                  * (2) if you do not have the old thing, you are not allowed
332                  *     to overwrite it; you would not know what you are losing
333                  *     otherwise.
334                  *
335                  * (3) if both new and old are commit-ish, and new is a
336                  *     descendant of old, it is OK.
337                  *
338                  * (4) regardless of all of the above, removing :B is
339                  *     always allowed.
340                  */
341
342                 if (!force_update &&
343                     !delete_ref &&
344                     !is_zero_sha1(ref->old_sha1) &&
345                     !ref->force) {
346                         if (!has_sha1_file(ref->old_sha1) ||
347                             !ref_newer(ref->peer_ref->new_sha1,
348                                        ref->old_sha1)) {
349                                 /* We do not have the remote ref, or
350                                  * we know that the remote ref is not
351                                  * an ancestor of what we are trying to
352                                  * push.  Either way this can be losing
353                                  * commits at the remote end and likely
354                                  * we were not up to date to begin with.
355                                  */
356                                 error("remote '%s' is not a strict "
357                                       "subset of local ref '%s'. "
358                                       "maybe you are not up-to-date and "
359                                       "need to pull first?",
360                                       ref->name,
361                                       ref->peer_ref->name);
362                                 ret = -2;
363                                 continue;
364                         }
365                 }
366                 hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
367                 if (!delete_ref)
368                         new_refs++;
369                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
370                 new_hex = sha1_to_hex(ref->new_sha1);
371
372                 if (ask_for_status_report) {
373                         packet_write(out, "%s %s %s%c%s",
374                                      old_hex, new_hex, ref->name, 0,
375                                      "report-status");
376                         ask_for_status_report = 0;
377                         expect_status_report = 1;
378                 }
379                 else
380                         packet_write(out, "%s %s %s",
381                                      old_hex, new_hex, ref->name);
382                 if (delete_ref)
383                         fprintf(stderr, "deleting '%s'\n", ref->name);
384                 else {
385                         fprintf(stderr, "updating '%s'", ref->name);
386                         if (strcmp(ref->name, ref->peer_ref->name))
387                                 fprintf(stderr, " using '%s'",
388                                         ref->peer_ref->name);
389                         fprintf(stderr, "\n  from %s\n  to   %s\n",
390                                 old_hex, new_hex);
391                 }
392         }
393
394         packet_flush(out);
395         if (new_refs)
396                 pack_objects(out, remote_refs);
397         close(out);
398
399         if (expect_status_report) {
400                 if (receive_status(in))
401                         ret = -4;
402         }
403
404         if (!new_refs && ret == 0)
405                 fprintf(stderr, "Everything up-to-date\n");
406         return ret;
407 }
408
409
410 int main(int argc, char **argv)
411 {
412         int i, nr_heads = 0;
413         char *dest = NULL;
414         char **heads = NULL;
415         int fd[2], ret;
416         pid_t pid;
417
418         setup_git_directory();
419         git_config(git_default_config);
420
421         argv++;
422         for (i = 1; i < argc; i++, argv++) {
423                 char *arg = *argv;
424
425                 if (*arg == '-') {
426                         if (!strncmp(arg, "--exec=", 7)) {
427                                 exec = arg + 7;
428                                 continue;
429                         }
430                         if (!strcmp(arg, "--all")) {
431                                 send_all = 1;
432                                 continue;
433                         }
434                         if (!strcmp(arg, "--force")) {
435                                 force_update = 1;
436                                 continue;
437                         }
438                         if (!strcmp(arg, "--verbose")) {
439                                 verbose = 1;
440                                 continue;
441                         }
442                         if (!strcmp(arg, "--thin")) {
443                                 use_thin_pack = 1;
444                                 continue;
445                         }
446                         usage(send_pack_usage);
447                 }
448                 if (!dest) {
449                         dest = arg;
450                         continue;
451                 }
452                 heads = argv;
453                 nr_heads = argc - i;
454                 break;
455         }
456         if (!dest)
457                 usage(send_pack_usage);
458         if (heads && send_all)
459                 usage(send_pack_usage);
460         pid = git_connect(fd, dest, exec);
461         if (pid < 0)
462                 return 1;
463         ret = send_pack(fd[0], fd[1], nr_heads, heads);
464         close(fd[0]);
465         close(fd[1]);
466         ret |= finish_connect(pid);
467         return !!ret;
468 }