Fix confusing git-update-ref error message
[git.git] / clone-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include <sys/wait.h>
5
6 static const char clone_pack_usage[] =
7 "git-clone-pack [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
8 static const char *exec = "git-upload-pack";
9
10 static void clone_handshake(int fd[2], struct ref *ref)
11 {
12         unsigned char sha1[20];
13
14         while (ref) {
15                 packet_write(fd[1], "want %s\n", sha1_to_hex(ref->old_sha1));
16                 ref = ref->next;
17         }
18         packet_flush(fd[1]);
19
20         /* We don't have nuttin' */
21         packet_write(fd[1], "done\n");
22         if (get_ack(fd[0], sha1))
23                 error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1));
24 }
25
26 static int is_master(struct ref *ref)
27 {
28         return !strcmp(ref->name, "refs/heads/master");
29 }
30
31 static void write_one_ref(struct ref *ref)
32 {
33         char *path = git_path("%s", ref->name);
34         int fd;
35         char *hex;
36
37         if (!strncmp(ref->name, "refs/", 5) &&
38             check_ref_format(ref->name + 5)) {
39                 error("refusing to create funny ref '%s' locally", ref->name);
40                 return;
41         }
42
43         if (safe_create_leading_directories(path))
44                 die("unable to create leading directory for %s", ref->name);
45         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
46         if (fd < 0)
47                 die("unable to create ref %s", ref->name);
48         hex = sha1_to_hex(ref->old_sha1);
49         hex[40] = '\n';
50         if (write(fd, hex, 41) != 41)
51                 die("unable to write ref %s", ref->name);
52         close(fd);
53 }
54
55 static void write_refs(struct ref *ref)
56 {
57         struct ref *head = NULL, *head_ptr, *master_ref;
58         char *head_path;
59
60         /* Upload-pack must report HEAD first */
61         if (!strcmp(ref->name, "HEAD")) {
62                 head = ref;
63                 ref = ref->next;
64         }
65         head_ptr = NULL;
66         master_ref = NULL;
67         while (ref) {
68                 if (is_master(ref))
69                         master_ref = ref;
70                 if (head &&
71                     !memcmp(ref->old_sha1, head->old_sha1, 20) &&
72                     !strncmp(ref->name, "refs/heads/",11) &&
73                     (!head_ptr || ref == master_ref))
74                         head_ptr = ref;
75
76                 write_one_ref(ref);
77                 ref = ref->next;
78         }
79         if (!head) {
80                 fprintf(stderr, "No HEAD in remote.\n");
81                 return;
82         }
83
84         head_path = strdup(git_path("HEAD"));
85         if (!head_ptr) {
86                 /*
87                  * If we had a master ref, and it wasn't HEAD, we need to undo the
88                  * symlink, and write a standalone HEAD. Give a warning, because that's
89                  * really really wrong.
90                  */
91                 if (master_ref) {
92                         error("HEAD doesn't point to any refs! Making standalone HEAD");
93                         unlink(head_path);
94                 }
95                 write_one_ref(head);
96                 free(head_path);
97                 return;
98         }
99
100         /* We reset to the master branch if it's available */
101         if (master_ref)
102                 return;
103
104         fprintf(stderr, "Setting HEAD to %s\n", head_ptr->name);
105
106         /*
107          * Uhhuh. Other end didn't have master. We start HEAD off with
108          * the first branch with the same value.
109          */
110         if (create_symref(head_path, head_ptr->name) < 0)
111                 die("unable to link HEAD to %s", head_ptr->name);
112         free(head_path);
113 }
114
115 static int finish_pack(const char *pack_tmp_name)
116 {
117         int pipe_fd[2];
118         pid_t pid;
119         char idx[PATH_MAX];
120         char final[PATH_MAX];
121         char hash[41];
122         unsigned char sha1[20];
123         char *cp;
124         int err = 0;
125
126         if (pipe(pipe_fd) < 0)
127                 die("git-clone-pack: unable to set up pipe");
128
129         strcpy(idx, pack_tmp_name); /* ".git/objects/pack-XXXXXX" */
130         cp = strrchr(idx, '/');
131         memcpy(cp, "/pidx", 5);
132
133         pid = fork();
134         if (pid < 0)
135                 die("git-clone-pack: unable to fork off git-index-pack");
136         if (!pid) {
137                 close(0);
138                 dup2(pipe_fd[1], 1);
139                 close(pipe_fd[0]);
140                 close(pipe_fd[1]);
141                 execlp("git-index-pack","git-index-pack",
142                        "-o", idx, pack_tmp_name, NULL);
143                 error("cannot exec git-index-pack <%s> <%s>",
144                       idx, pack_tmp_name);
145                 exit(1);
146         }
147         close(pipe_fd[1]);
148         if (read(pipe_fd[0], hash, 40) != 40) {
149                 error("git-clone-pack: unable to read from git-index-pack");
150                 err = 1;
151         }
152         close(pipe_fd[0]);
153
154         for (;;) {
155                 int status, code;
156                 int retval = waitpid(pid, &status, 0);
157
158                 if (retval < 0) {
159                         if (errno == EINTR)
160                                 continue;
161                         error("waitpid failed (%s)", strerror(retval));
162                         goto error_die;
163                 }
164                 if (WIFSIGNALED(status)) {
165                         int sig = WTERMSIG(status);
166                         error("git-index-pack died of signal %d", sig);
167                         goto error_die;
168                 }
169                 if (!WIFEXITED(status)) {
170                         error("git-index-pack died of unnatural causes %d",
171                               status);
172                         goto error_die;
173                 }
174                 code = WEXITSTATUS(status);
175                 if (code) {
176                         error("git-index-pack died with error code %d", code);
177                         goto error_die;
178                 }
179                 if (err)
180                         goto error_die;
181                 break;
182         }
183         hash[40] = 0;
184         if (get_sha1_hex(hash, sha1)) {
185                 error("git-index-pack reported nonsense '%s'", hash);
186                 goto error_die;
187         }
188         /* Now we have pack in pack_tmp_name[], and
189          * idx in idx[]; rename them to their final names.
190          */
191         snprintf(final, sizeof(final),
192                  "%s/pack/pack-%s.pack", get_object_directory(), hash);
193         move_temp_to_file(pack_tmp_name, final);
194         chmod(final, 0444);
195         snprintf(final, sizeof(final),
196                  "%s/pack/pack-%s.idx", get_object_directory(), hash);
197         move_temp_to_file(idx, final);
198         chmod(final, 0444);
199         return 0;
200
201  error_die:
202         unlink(idx);
203         unlink(pack_tmp_name);
204         exit(1);
205 }
206
207 static int clone_without_unpack(int fd[2])
208 {
209         char tmpfile[PATH_MAX];
210         int ofd, ifd;
211
212         ifd = fd[0];
213         snprintf(tmpfile, sizeof(tmpfile),
214                  "%s/pack/tmp-XXXXXX", get_object_directory());
215         ofd = mkstemp(tmpfile);
216         if (ofd < 0)
217                 return error("unable to create temporary file %s", tmpfile);
218
219         while (1) {
220                 char buf[8192];
221                 ssize_t sz, wsz, pos;
222                 sz = read(ifd, buf, sizeof(buf));
223                 if (sz == 0)
224                         break;
225                 if (sz < 0) {
226                         error("error reading pack (%s)", strerror(errno));
227                         close(ofd);
228                         unlink(tmpfile);
229                         return -1;
230                 }
231                 pos = 0;
232                 while (pos < sz) {
233                         wsz = write(ofd, buf + pos, sz - pos);
234                         if (wsz < 0) {
235                                 error("error writing pack (%s)",
236                                       strerror(errno));
237                                 close(ofd);
238                                 unlink(tmpfile);
239                                 return -1;
240                         }
241                         pos += wsz;
242                 }
243         }
244         close(ofd);
245         return finish_pack(tmpfile);
246 }
247
248 static int clone_pack(int fd[2], int nr_match, char **match)
249 {
250         struct ref *refs;
251         int status;
252
253         get_remote_heads(fd[0], &refs, nr_match, match, 1);
254         if (!refs) {
255                 packet_flush(fd[1]);
256                 die("no matching remote head");
257         }
258         clone_handshake(fd, refs);
259
260         status = clone_without_unpack(fd);
261
262         if (!status)
263                 write_refs(refs);
264         return status;
265 }
266
267 int main(int argc, char **argv)
268 {
269         int i, ret, nr_heads;
270         char *dest = NULL, **heads;
271         int fd[2];
272         pid_t pid;
273
274         nr_heads = 0;
275         heads = NULL;
276         for (i = 1; i < argc; i++) {
277                 char *arg = argv[i];
278
279                 if (*arg == '-') {
280                         if (!strcmp("-q", arg))
281                                 continue;
282                         if (!strncmp("--exec=", arg, 7)) {
283                                 exec = arg + 7;
284                                 continue;
285                         }
286                         if (!strcmp("--keep", arg))
287                                 continue;
288                         usage(clone_pack_usage);
289                 }
290                 dest = arg;
291                 heads = argv + i + 1;
292                 nr_heads = argc - i - 1;
293                 break;
294         }
295         if (!dest)
296                 usage(clone_pack_usage);
297         pid = git_connect(fd, dest, exec);
298         if (pid < 0)
299                 return 1;
300         ret = clone_pack(fd, nr_heads, heads);
301         close(fd[0]);
302         close(fd[1]);
303         finish_connect(pid);
304         return ret;
305 }