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[git.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 = 0;
13 static int send_all = 0;
14 static int force_update = 0;
15
16 static int is_zero_sha1(const unsigned char *sha1)
17 {
18         int i;
19
20         for (i = 0; i < 20; i++) {
21                 if (*sha1++)
22                         return 0;
23         }
24         return 1;
25 }
26
27 static void exec_pack_objects(void)
28 {
29         static char *args[] = {
30                 "pack-objects",
31                 "--stdout",
32                 NULL
33         };
34         execv_git_cmd(args);
35         die("git-pack-objects exec failed (%s)", strerror(errno));
36 }
37
38 static void exec_rev_list(struct ref *refs)
39 {
40         static char *args[1000];
41         int i = 0;
42
43         args[i++] = "rev-list"; /* 0 */
44         args[i++] = "--objects";        /* 1 */
45         while (refs) {
46                 char *buf = malloc(100);
47                 if (i > 900)
48                         die("git-rev-list environment overflow");
49                 if (!is_zero_sha1(refs->old_sha1) &&
50                     has_sha1_file(refs->old_sha1)) {
51                         args[i++] = buf;
52                         snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
53                         buf += 50;
54                 }
55                 if (!is_zero_sha1(refs->new_sha1)) {
56                         args[i++] = buf;
57                         snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
58                 }
59                 refs = refs->next;
60         }
61         args[i] = NULL;
62         execv_git_cmd(args);
63         die("git-rev-list exec failed (%s)", strerror(errno));
64 }
65
66 static void rev_list(int fd, struct ref *refs)
67 {
68         int pipe_fd[2];
69         pid_t pack_objects_pid;
70
71         if (pipe(pipe_fd) < 0)
72                 die("rev-list setup: pipe failed");
73         pack_objects_pid = fork();
74         if (!pack_objects_pid) {
75                 dup2(pipe_fd[0], 0);
76                 dup2(fd, 1);
77                 close(pipe_fd[0]);
78                 close(pipe_fd[1]);
79                 close(fd);
80                 exec_pack_objects();
81                 die("pack-objects setup failed");
82         }
83         if (pack_objects_pid < 0)
84                 die("pack-objects fork failed");
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 static int pack_objects(int fd, struct ref *refs)
93 {
94         pid_t rev_list_pid;
95
96         rev_list_pid = fork();
97         if (!rev_list_pid) {
98                 rev_list(fd, refs);
99                 die("rev-list setup failed");
100         }
101         if (rev_list_pid < 0)
102                 die("rev-list fork failed");
103         /*
104          * We don't wait for the rev-list pipeline in the parent:
105          * we end up waiting for the other end instead
106          */
107         return 0;
108 }
109
110 static void unmark_and_free(struct commit_list *list, unsigned int mark)
111 {
112         while (list) {
113                 struct commit_list *temp = list;
114                 temp->item->object.flags &= ~mark;
115                 list = temp->next;
116                 free(temp);
117         }
118 }
119
120 static int ref_newer(const unsigned char *new_sha1,
121                      const unsigned char *old_sha1)
122 {
123         struct object *o;
124         struct commit *old, *new;
125         struct commit_list *list, *used;
126         int found = 0;
127
128         /* Both new and old must be commit-ish and new is descendant of
129          * old.  Otherwise we require --force.
130          */
131         o = deref_tag(parse_object(old_sha1), NULL, 0);
132         if (!o || o->type != commit_type)
133                 return 0;
134         old = (struct commit *) o;
135
136         o = deref_tag(parse_object(new_sha1), NULL, 0);
137         if (!o || o->type != commit_type)
138                 return 0;
139         new = (struct commit *) o;
140
141         if (parse_commit(new) < 0)
142                 return 0;
143
144         used = list = NULL;
145         commit_list_insert(new, &list);
146         while (list) {
147                 new = pop_most_recent_commit(&list, 1);
148                 commit_list_insert(new, &used);
149                 if (new == old) {
150                         found = 1;
151                         break;
152                 }
153         }
154         unmark_and_free(list, 1);
155         unmark_and_free(used, 1);
156         return found;
157 }
158
159 static struct ref *local_refs, **local_tail;
160 static struct ref *remote_refs, **remote_tail;
161
162 static int one_local_ref(const char *refname, const unsigned char *sha1)
163 {
164         struct ref *ref;
165         int len = strlen(refname) + 1;
166         ref = xcalloc(1, sizeof(*ref) + len);
167         memcpy(ref->new_sha1, sha1, 20);
168         memcpy(ref->name, refname, len);
169         *local_tail = ref;
170         local_tail = &ref->next;
171         return 0;
172 }
173
174 static void get_local_heads(void)
175 {
176         local_tail = &local_refs;
177         for_each_ref(one_local_ref);
178 }
179
180 static int receive_status(int in)
181 {
182         char line[1000];
183         int ret = 0;
184         int len = packet_read_line(in, line, sizeof(line));
185         if (len < 10 || memcmp(line, "unpack ", 7)) {
186                 fprintf(stderr, "did not receive status back\n");
187                 return -1;
188         }
189         if (memcmp(line, "unpack ok\n", 10)) {
190                 fputs(line, stderr);
191                 ret = -1;
192         }
193         while (1) {
194                 len = packet_read_line(in, line, sizeof(line));
195                 if (!len)
196                         break;
197                 if (len < 3 ||
198                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
199                         fprintf(stderr, "protocol error: %s\n", line);
200                         ret = -1;
201                         break;
202                 }
203                 if (!memcmp(line, "ok", 2))
204                         continue;
205                 fputs(line, stderr);
206                 ret = -1;
207         }
208         return ret;
209 }
210
211 static int send_pack(int in, int out, int nr_refspec, char **refspec)
212 {
213         struct ref *ref;
214         int new_refs;
215         int ret = 0;
216         int ask_for_status_report = 0;
217         int expect_status_report = 0;
218
219         /* No funny business with the matcher */
220         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
221         get_local_heads();
222
223         /* Does the other end support the reporting? */
224         if (server_supports("report-status"))
225                 ask_for_status_report = 1;
226
227         /* match them up */
228         if (!remote_tail)
229                 remote_tail = &remote_refs;
230         if (match_refs(local_refs, remote_refs, &remote_tail,
231                        nr_refspec, refspec, send_all))
232                 return -1;
233
234         if (!remote_refs) {
235                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
236                 return 0;
237         }
238
239         /*
240          * Finally, tell the other end!
241          */
242         new_refs = 0;
243         for (ref = remote_refs; ref; ref = ref->next) {
244                 char old_hex[60], *new_hex;
245                 if (!ref->peer_ref)
246                         continue;
247                 if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
248                         if (verbose)
249                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
250                         continue;
251                 }
252
253                 /* This part determines what can overwrite what.
254                  * The rules are:
255                  *
256                  * (0) you can always use --force or +A:B notation to
257                  *     selectively force individual ref pairs.
258                  *
259                  * (1) if the old thing does not exist, it is OK.
260                  *
261                  * (2) if you do not have the old thing, you are not allowed
262                  *     to overwrite it; you would not know what you are losing
263                  *     otherwise.
264                  *
265                  * (3) if both new and old are commit-ish, and new is a
266                  *     descendant of old, it is OK.
267                  */
268
269                 if (!force_update &&
270                     !is_zero_sha1(ref->old_sha1) &&
271                     !ref->force) {
272                         if (!has_sha1_file(ref->old_sha1) ||
273                             !ref_newer(ref->peer_ref->new_sha1,
274                                        ref->old_sha1)) {
275                                 /* We do not have the remote ref, or
276                                  * we know that the remote ref is not
277                                  * an ancestor of what we are trying to
278                                  * push.  Either way this can be losing
279                                  * commits at the remote end and likely
280                                  * we were not up to date to begin with.
281                                  */
282                                 error("remote '%s' is not a strict "
283                                       "subset of local ref '%s'. "
284                                       "maybe you are not up-to-date and "
285                                       "need to pull first?",
286                                       ref->name,
287                                       ref->peer_ref->name);
288                                 ret = -2;
289                                 continue;
290                         }
291                 }
292                 memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
293                 if (is_zero_sha1(ref->new_sha1)) {
294                         error("cannot happen anymore");
295                         ret = -3;
296                         continue;
297                 }
298                 new_refs++;
299                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
300                 new_hex = sha1_to_hex(ref->new_sha1);
301
302                 if (ask_for_status_report) {
303                         packet_write(out, "%s %s %s%c%s",
304                                      old_hex, new_hex, ref->name, 0,
305                                      "report-status");
306                         ask_for_status_report = 0;
307                         expect_status_report = 1;
308                 }
309                 else
310                         packet_write(out, "%s %s %s",
311                                      old_hex, new_hex, ref->name);
312                 fprintf(stderr, "updating '%s'", ref->name);
313                 if (strcmp(ref->name, ref->peer_ref->name))
314                         fprintf(stderr, " using '%s'", ref->peer_ref->name);
315                 fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
316         }
317
318         packet_flush(out);
319         if (new_refs)
320                 pack_objects(out, remote_refs);
321         close(out);
322
323         if (expect_status_report) {
324                 if (receive_status(in))
325                         ret = -4;
326         }
327
328         if (!new_refs && ret == 0)
329                 fprintf(stderr, "Everything up-to-date\n");
330         return ret;
331 }
332
333
334 int main(int argc, char **argv)
335 {
336         int i, nr_heads = 0;
337         char *dest = NULL;
338         char **heads = NULL;
339         int fd[2], ret;
340         pid_t pid;
341
342         setup_git_directory();
343         argv++;
344         for (i = 1; i < argc; i++, argv++) {
345                 char *arg = *argv;
346
347                 if (*arg == '-') {
348                         if (!strncmp(arg, "--exec=", 7)) {
349                                 exec = arg + 7;
350                                 continue;
351                         }
352                         if (!strcmp(arg, "--all")) {
353                                 send_all = 1;
354                                 continue;
355                         }
356                         if (!strcmp(arg, "--force")) {
357                                 force_update = 1;
358                                 continue;
359                         }
360                         if (!strcmp(arg, "--verbose")) {
361                                 verbose = 1;
362                                 continue;
363                         }
364                         usage(send_pack_usage);
365                 }
366                 if (!dest) {
367                         dest = arg;
368                         continue;
369                 }
370                 heads = argv;
371                 nr_heads = argc - i;
372                 break;
373         }
374         if (!dest)
375                 usage(send_pack_usage);
376         if (heads && send_all)
377                 usage(send_pack_usage);
378         pid = git_connect(fd, dest, exec);
379         if (pid < 0)
380                 return 1;
381         ret = send_pack(fd[0], fd[1], nr_heads, heads);
382         close(fd[0]);
383         close(fd[1]);
384         finish_connect(pid);
385         return ret;
386 }