git-clone: always keep pack sent from remote.
[git/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-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 }