1#include "cache.h"
2#include "refs.h"
3#include "pkt-line.h"
4#include <sys/wait.h>
5
6static int quiet;
7static const char clone_pack_usage[] = "git-clone-pack [-q] [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
8static const char *exec = "git-upload-pack";
9
10static 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
26static int is_master(struct ref *ref)
27{
28 return !strcmp(ref->name, "refs/heads/master");
29}
30
31static 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 (safe_create_leading_directories(path))
38 die("unable to create leading directory for %s", ref->name);
39 fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
40 if (fd < 0)
41 die("unable to create ref %s", ref->name);
42 hex = sha1_to_hex(ref->old_sha1);
43 hex[40] = '\n';
44 if (write(fd, hex, 41) != 41)
45 die("unable to write ref %s", ref->name);
46 close(fd);
47}
48
49static void write_refs(struct ref *ref)
50{
51 struct ref *head = NULL, *head_ptr, *master_ref;
52 char *head_path;
53
54 /* Upload-pack must report HEAD first */
55 if (!strcmp(ref->name, "HEAD")) {
56 head = ref;
57 ref = ref->next;
58 }
59 head_ptr = NULL;
60 master_ref = NULL;
61 while (ref) {
62 if (is_master(ref))
63 master_ref = ref;
64 if (head &&
65 !memcmp(ref->old_sha1, head->old_sha1, 20) &&
66 !strncmp(ref->name, "refs/heads/",11) &&
67 (!head_ptr || ref == master_ref))
68 head_ptr = ref;
69
70 write_one_ref(ref);
71 ref = ref->next;
72 }
73 if (!head) {
74 fprintf(stderr, "No HEAD in remote.\n");
75 return;
76 }
77
78 head_path = strdup(git_path("HEAD"));
79 if (!head_ptr) {
80 /*
81 * If we had a master ref, and it wasn't HEAD, we need to undo the
82 * symlink, and write a standalone HEAD. Give a warning, because that's
83 * really really wrong.
84 */
85 if (master_ref) {
86 error("HEAD doesn't point to any refs! Making standalone HEAD");
87 unlink(head_path);
88 }
89 write_one_ref(head);
90 free(head_path);
91 return;
92 }
93
94 /* We reset to the master branch if it's available */
95 if (master_ref)
96 return;
97
98 fprintf(stderr, "Setting HEAD to %s\n", head_ptr->name);
99
100 /*
101 * Uhhuh. Other end didn't have master. We start HEAD off with
102 * the first branch with the same value.
103 */
104 if (create_symref(head_path, head_ptr->name) < 0)
105 die("unable to link HEAD to %s", head_ptr->name);
106 free(head_path);
107}
108
109static int clone_pack(int fd[2], int nr_match, char **match)
110{
111 struct ref *refs;
112 int status;
113 pid_t pid;
114
115 get_remote_heads(fd[0], &refs, nr_match, match);
116 if (!refs) {
117 packet_flush(fd[1]);
118 die("no matching remote head");
119 }
120 clone_handshake(fd, refs);
121 pid = fork();
122 if (pid < 0)
123 die("git-clone-pack: unable to fork off git-unpack-objects");
124 if (!pid) {
125 dup2(fd[0], 0);
126 close(fd[0]);
127 close(fd[1]);
128 execlp("git-unpack-objects", "git-unpack-objects",
129 quiet ? "-q" : NULL, NULL);
130 die("git-unpack-objects exec failed");
131 }
132 close(fd[0]);
133 close(fd[1]);
134 while (waitpid(pid, &status, 0) < 0) {
135 if (errno != EINTR)
136 die("waiting for git-unpack-objects: %s", strerror(errno));
137 }
138 if (WIFEXITED(status)) {
139 int code = WEXITSTATUS(status);
140 if (code)
141 die("git-unpack-objects died with error code %d", code);
142 write_refs(refs);
143 return 0;
144 }
145 if (WIFSIGNALED(status)) {
146 int sig = WTERMSIG(status);
147 die("git-unpack-objects died of signal %d", sig);
148 }
149 die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
150}
151
152int main(int argc, char **argv)
153{
154 int i, ret, nr_heads;
155 char *dest = NULL, **heads;
156 int fd[2];
157 pid_t pid;
158
159 nr_heads = 0;
160 heads = NULL;
161 for (i = 1; i < argc; i++) {
162 char *arg = argv[i];
163
164 if (*arg == '-') {
165 if (!strcmp("-q", arg)) {
166 quiet = 1;
167 continue;
168 }
169 if (!strncmp("--exec=", arg, 7)) {
170 exec = arg + 7;
171 continue;
172 }
173 usage(clone_pack_usage);
174 }
175 dest = arg;
176 heads = argv + i + 1;
177 nr_heads = argc - i - 1;
178 break;
179 }
180 if (!dest)
181 usage(clone_pack_usage);
182 pid = git_connect(fd, dest, exec);
183 if (pid < 0)
184 return 1;
185 ret = clone_pack(fd, nr_heads, heads);
186 close(fd[0]);
187 close(fd[1]);
188 finish_connect(pid);
189 return ret;
190}