Improve the git-diff-tree -c/-cc documentation
[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 static int use_thin_pack = 0;
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                 "--stdout",
33                 NULL
34         };
35         execv_git_cmd(args);
36         die("git-pack-objects exec failed (%s)", strerror(errno));
37 }
38
39 static void exec_rev_list(struct ref *refs)
40 {
41         struct ref *ref;
42         static const char *args[1000];
43         int i = 0, j;
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         /* First send the ones we care about most */
52         for (ref = refs; ref; ref = ref->next) {
53                 if (900 < i)
54                         die("git-rev-list environment overflow");
55                 if (!is_zero_sha1(ref->new_sha1)) {
56                         char *buf = malloc(100);
57                         args[i++] = buf;
58                         snprintf(buf, 50, "%s", sha1_to_hex(ref->new_sha1));
59                         buf += 50;
60                         if (!is_zero_sha1(ref->old_sha1) &&
61                             has_sha1_file(ref->old_sha1)) {
62                                 args[i++] = buf;
63                                 snprintf(buf, 50, "^%s",
64                                          sha1_to_hex(ref->old_sha1));
65                         }
66                 }
67         }
68
69         /* Then a handful of the remainder
70          * NEEDSWORK: we would be better off if used the newer ones first.
71          */
72         for (ref = refs, j = i + 16;
73              i < 900 && i < j && ref;
74              ref = ref->next) {
75                 if (is_zero_sha1(ref->new_sha1) &&
76                     !is_zero_sha1(ref->old_sha1) &&
77                     has_sha1_file(ref->old_sha1)) {
78                         char *buf = malloc(42);
79                         args[i++] = buf;
80                         snprintf(buf, 42, "^%s", sha1_to_hex(ref->old_sha1));
81                 }
82         }
83         args[i] = NULL;
84         execv_git_cmd(args);
85         die("git-rev-list exec failed (%s)", strerror(errno));
86 }
87
88 static void rev_list(int fd, struct ref *refs)
89 {
90         int pipe_fd[2];
91         pid_t pack_objects_pid;
92
93         if (pipe(pipe_fd) < 0)
94                 die("rev-list setup: pipe failed");
95         pack_objects_pid = fork();
96         if (!pack_objects_pid) {
97                 dup2(pipe_fd[0], 0);
98                 dup2(fd, 1);
99                 close(pipe_fd[0]);
100                 close(pipe_fd[1]);
101                 close(fd);
102                 exec_pack_objects();
103                 die("pack-objects setup failed");
104         }
105         if (pack_objects_pid < 0)
106                 die("pack-objects fork failed");
107         dup2(pipe_fd[1], 1);
108         close(pipe_fd[0]);
109         close(pipe_fd[1]);
110         close(fd);
111         exec_rev_list(refs);
112 }
113
114 static int pack_objects(int fd, struct ref *refs)
115 {
116         pid_t rev_list_pid;
117
118         rev_list_pid = fork();
119         if (!rev_list_pid) {
120                 rev_list(fd, refs);
121                 die("rev-list setup failed");
122         }
123         if (rev_list_pid < 0)
124                 die("rev-list fork failed");
125         /*
126          * We don't wait for the rev-list pipeline in the parent:
127          * we end up waiting for the other end instead
128          */
129         return 0;
130 }
131
132 static void unmark_and_free(struct commit_list *list, unsigned int mark)
133 {
134         while (list) {
135                 struct commit_list *temp = list;
136                 temp->item->object.flags &= ~mark;
137                 list = temp->next;
138                 free(temp);
139         }
140 }
141
142 static int ref_newer(const unsigned char *new_sha1,
143                      const unsigned char *old_sha1)
144 {
145         struct object *o;
146         struct commit *old, *new;
147         struct commit_list *list, *used;
148         int found = 0;
149
150         /* Both new and old must be commit-ish and new is descendant of
151          * old.  Otherwise we require --force.
152          */
153         o = deref_tag(parse_object(old_sha1), NULL, 0);
154         if (!o || o->type != commit_type)
155                 return 0;
156         old = (struct commit *) o;
157
158         o = deref_tag(parse_object(new_sha1), NULL, 0);
159         if (!o || o->type != commit_type)
160                 return 0;
161         new = (struct commit *) o;
162
163         if (parse_commit(new) < 0)
164                 return 0;
165
166         used = list = NULL;
167         commit_list_insert(new, &list);
168         while (list) {
169                 new = pop_most_recent_commit(&list, 1);
170                 commit_list_insert(new, &used);
171                 if (new == old) {
172                         found = 1;
173                         break;
174                 }
175         }
176         unmark_and_free(list, 1);
177         unmark_and_free(used, 1);
178         return found;
179 }
180
181 static struct ref *local_refs, **local_tail;
182 static struct ref *remote_refs, **remote_tail;
183
184 static int one_local_ref(const char *refname, const unsigned char *sha1)
185 {
186         struct ref *ref;
187         int len = strlen(refname) + 1;
188         ref = xcalloc(1, sizeof(*ref) + len);
189         memcpy(ref->new_sha1, sha1, 20);
190         memcpy(ref->name, refname, len);
191         *local_tail = ref;
192         local_tail = &ref->next;
193         return 0;
194 }
195
196 static void get_local_heads(void)
197 {
198         local_tail = &local_refs;
199         for_each_ref(one_local_ref);
200 }
201
202 static int receive_status(int in)
203 {
204         char line[1000];
205         int ret = 0;
206         int len = packet_read_line(in, line, sizeof(line));
207         if (len < 10 || memcmp(line, "unpack ", 7)) {
208                 fprintf(stderr, "did not receive status back\n");
209                 return -1;
210         }
211         if (memcmp(line, "unpack ok\n", 10)) {
212                 fputs(line, stderr);
213                 ret = -1;
214         }
215         while (1) {
216                 len = packet_read_line(in, line, sizeof(line));
217                 if (!len)
218                         break;
219                 if (len < 3 ||
220                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
221                         fprintf(stderr, "protocol error: %s\n", line);
222                         ret = -1;
223                         break;
224                 }
225                 if (!memcmp(line, "ok", 2))
226                         continue;
227                 fputs(line, stderr);
228                 ret = -1;
229         }
230         return ret;
231 }
232
233 static int send_pack(int in, int out, int nr_refspec, char **refspec)
234 {
235         struct ref *ref;
236         int new_refs;
237         int ret = 0;
238         int ask_for_status_report = 0;
239         int expect_status_report = 0;
240
241         /* No funny business with the matcher */
242         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
243         get_local_heads();
244
245         /* Does the other end support the reporting? */
246         if (server_supports("report-status"))
247                 ask_for_status_report = 1;
248
249         /* match them up */
250         if (!remote_tail)
251                 remote_tail = &remote_refs;
252         if (match_refs(local_refs, remote_refs, &remote_tail,
253                        nr_refspec, refspec, send_all))
254                 return -1;
255
256         if (!remote_refs) {
257                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
258                 return 0;
259         }
260
261         /*
262          * Finally, tell the other end!
263          */
264         new_refs = 0;
265         for (ref = remote_refs; ref; ref = ref->next) {
266                 char old_hex[60], *new_hex;
267                 if (!ref->peer_ref)
268                         continue;
269                 if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
270                         if (verbose)
271                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
272                         continue;
273                 }
274
275                 /* This part determines what can overwrite what.
276                  * The rules are:
277                  *
278                  * (0) you can always use --force or +A:B notation to
279                  *     selectively force individual ref pairs.
280                  *
281                  * (1) if the old thing does not exist, it is OK.
282                  *
283                  * (2) if you do not have the old thing, you are not allowed
284                  *     to overwrite it; you would not know what you are losing
285                  *     otherwise.
286                  *
287                  * (3) if both new and old are commit-ish, and new is a
288                  *     descendant of old, it is OK.
289                  */
290
291                 if (!force_update &&
292                     !is_zero_sha1(ref->old_sha1) &&
293                     !ref->force) {
294                         if (!has_sha1_file(ref->old_sha1) ||
295                             !ref_newer(ref->peer_ref->new_sha1,
296                                        ref->old_sha1)) {
297                                 /* We do not have the remote ref, or
298                                  * we know that the remote ref is not
299                                  * an ancestor of what we are trying to
300                                  * push.  Either way this can be losing
301                                  * commits at the remote end and likely
302                                  * we were not up to date to begin with.
303                                  */
304                                 error("remote '%s' is not a strict "
305                                       "subset of local ref '%s'. "
306                                       "maybe you are not up-to-date and "
307                                       "need to pull first?",
308                                       ref->name,
309                                       ref->peer_ref->name);
310                                 ret = -2;
311                                 continue;
312                         }
313                 }
314                 memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
315                 if (is_zero_sha1(ref->new_sha1)) {
316                         error("cannot happen anymore");
317                         ret = -3;
318                         continue;
319                 }
320                 new_refs++;
321                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
322                 new_hex = sha1_to_hex(ref->new_sha1);
323
324                 if (ask_for_status_report) {
325                         packet_write(out, "%s %s %s%c%s",
326                                      old_hex, new_hex, ref->name, 0,
327                                      "report-status");
328                         ask_for_status_report = 0;
329                         expect_status_report = 1;
330                 }
331                 else
332                         packet_write(out, "%s %s %s",
333                                      old_hex, new_hex, ref->name);
334                 fprintf(stderr, "updating '%s'", ref->name);
335                 if (strcmp(ref->name, ref->peer_ref->name))
336                         fprintf(stderr, " using '%s'", ref->peer_ref->name);
337                 fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
338         }
339
340         packet_flush(out);
341         if (new_refs)
342                 pack_objects(out, remote_refs);
343         close(out);
344
345         if (expect_status_report) {
346                 if (receive_status(in))
347                         ret = -4;
348         }
349
350         if (!new_refs && ret == 0)
351                 fprintf(stderr, "Everything up-to-date\n");
352         return ret;
353 }
354
355
356 int main(int argc, char **argv)
357 {
358         int i, nr_heads = 0;
359         char *dest = NULL;
360         char **heads = NULL;
361         int fd[2], ret;
362         pid_t pid;
363
364         setup_git_directory();
365         git_config(git_default_config);
366
367         argv++;
368         for (i = 1; i < argc; i++, argv++) {
369                 char *arg = *argv;
370
371                 if (*arg == '-') {
372                         if (!strncmp(arg, "--exec=", 7)) {
373                                 exec = arg + 7;
374                                 continue;
375                         }
376                         if (!strcmp(arg, "--all")) {
377                                 send_all = 1;
378                                 continue;
379                         }
380                         if (!strcmp(arg, "--force")) {
381                                 force_update = 1;
382                                 continue;
383                         }
384                         if (!strcmp(arg, "--verbose")) {
385                                 verbose = 1;
386                                 continue;
387                         }
388                         if (!strcmp(arg, "--thin")) {
389                                 use_thin_pack = 1;
390                                 continue;
391                         }
392                         usage(send_pack_usage);
393                 }
394                 if (!dest) {
395                         dest = arg;
396                         continue;
397                 }
398                 heads = argv;
399                 nr_heads = argc - i;
400                 break;
401         }
402         if (!dest)
403                 usage(send_pack_usage);
404         if (heads && send_all)
405                 usage(send_pack_usage);
406         pid = git_connect(fd, dest, exec);
407         if (pid < 0)
408                 return 1;
409         ret = send_pack(fd[0], fd[1], nr_heads, heads);
410         close(fd[0]);
411         close(fd[1]);
412         finish_connect(pid);
413         return ret;
414 }