Merge master.kernel.org:/pub/scm/gitk/gitk
[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[] = "git-clone-pack [host:]directory [heads]*";
7 static const char *exec = "git-upload-pack";
8
9 struct ref {
10 struct ref *next;
11 unsigned char sha1[20];
12 char name[0];
13 };
14
15 struct ref *get_remote_refs(int fd, int nr_match, char **match)
16 {
17 struct ref *ref_list = NULL, **next_ref = &ref_list;
18
19 for (;;) {
20 static char line[1000];
21 unsigned char sha1[20];
22 struct ref *ref;
23 char *refname;
24 int len;
25
26 len = packet_read_line(fd, line, sizeof(line));
27 if (!len)
28 break;
29 if (line[len-1] == '\n')
30 line[--len] = 0;
31 if (len < 42 || get_sha1_hex(line, sha1))
32 die("git-fetch-pack: protocol error - expected ref descriptor, got '%s¤'", line);
33 refname = line+41;
34 len = len-40;
35 if (nr_match && !path_match(refname, nr_match, match))
36 continue;
37 ref = xmalloc(sizeof(struct ref) + len);
38 ref->next = NULL;
39 memcpy(ref->sha1, sha1, 20);
40 memcpy(ref->name, refname, len);
41 *next_ref = ref;
42 next_ref = &ref->next;
43 }
44 return ref_list;
45 }
46
47 static void clone_handshake(int fd[2], struct ref *ref)
48 {
49 unsigned char sha1[20];
50
51 while (ref) {
52 packet_write(fd[1], "want %s\n", sha1_to_hex(ref->sha1));
53 ref = ref->next;
54 }
55 packet_flush(fd[1]);
56
57 /* We don't have nuttin' */
58 packet_write(fd[1], "done\n");
59 if (get_ack(fd[0], sha1))
60 error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1));
61 }
62
63 static int is_master(struct ref *ref)
64 {
65 return !strcmp(ref->name, "refs/heads/master");
66 }
67
68 static void write_one_ref(struct ref *ref)
69 {
70 char *path = git_path(ref->name);
71 int fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
72 char *hex;
73
74 if (fd < 0)
75 die("unable to create ref %s", ref->name);
76 hex = sha1_to_hex(ref->sha1);
77 hex[40] = '\n';
78 if (write(fd, hex, 41) != 41)
79 die("unable to write ref %s", ref->name);
80 close(fd);
81 }
82
83 static void write_refs(struct ref *ref)
84 {
85 struct ref *head = NULL, *head_ptr, *master_ref;
86 char *head_path;
87
88 if (!strcmp(ref->name, "HEAD")) {
89 head = ref;
90 ref = ref->next;
91 }
92 head_ptr = NULL;
93 master_ref = NULL;
94 while (ref) {
95 if (is_master(ref))
96 master_ref = ref;
97 if (head && !memcmp(ref->sha1, head->sha1, 20)) {
98 if (!head_ptr || ref == master_ref)
99 head_ptr = ref;
100 }
101 write_one_ref(ref);
102 ref = ref->next;
103 }
104 if (!head)
105 return;
106
107 head_path = git_path("HEAD");
108 if (!head_ptr) {
109 /*
110 * If we had a master ref, and it wasn't HEAD, we need to undo the
111 * symlink, and write a standalone HEAD. Give a warning, because that's
112 * really really wrong.
113 */
114 if (master_ref) {
115 error("HEAD doesn't point to any refs! Making standalone HEAD");
116 unlink(head_path);
117 }
118 write_one_ref(head);
119 return;
120 }
121
122 /* We reset to the master branch if it's available */
123 if (master_ref)
124 return;
125
126 /*
127 * Uhhuh. Other end didn't have master. We start HEAD off with
128 * the first branch with the same value.
129 */
130 unlink(head_path);
131 if (symlink(head_ptr->name, head_path) < 0)
132 die("unable to link HEAD to %s", head_ptr->name);
133 }
134
135 static int clone_pack(int fd[2], int nr_match, char **match)
136 {
137 struct ref *refs;
138 int status;
139 pid_t pid;
140
141 refs = get_remote_refs(fd[0], nr_match, match);
142 if (!refs) {
143 packet_flush(fd[1]);
144 die("no matching remote head");
145 }
146 clone_handshake(fd, refs);
147 pid = fork();
148 if (pid < 0)
149 die("git-clone-pack: unable to fork off git-unpack-objects");
150 if (!pid) {
151 close(fd[1]);
152 dup2(fd[0], 0);
153 close(fd[0]);
154 execlp("git-unpack-objects", "git-unpack-objects", NULL);
155 die("git-unpack-objects exec failed");
156 }
157 close(fd[0]);
158 close(fd[1]);
159 while (waitpid(pid, &status, 0) < 0) {
160 if (errno != EINTR)
161 die("waiting for git-unpack-objects: %s", strerror(errno));
162 }
163 if (WIFEXITED(status)) {
164 int code = WEXITSTATUS(status);
165 if (code)
166 die("git-unpack-objects died with error code %d", code);
167 write_refs(refs);
168 return 0;
169 }
170 if (WIFSIGNALED(status)) {
171 int sig = WTERMSIG(status);
172 die("git-unpack-objects died of signal %d", sig);
173 }
174 die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
175 }
176
177 int main(int argc, char **argv)
178 {
179 int i, ret, nr_heads;
180 char *dest = NULL, **heads;
181 int fd[2];
182 pid_t pid;
183
184 nr_heads = 0;
185 heads = NULL;
186 for (i = 1; i < argc; i++) {
187 char *arg = argv[i];
188
189 if (*arg == '-') {
190 /* Arguments go here */
191 usage(clone_pack_usage);
192 }
193 dest = arg;
194 heads = argv + i + 1;
195 nr_heads = argc - i - 1;
196 break;
197 }
198 if (!dest)
199 usage(clone_pack_usage);
200 pid = git_connect(fd, dest, exec);
201 if (pid < 0)
202 return 1;
203 ret = clone_pack(fd, nr_heads, heads);
204 close(fd[0]);
205 close(fd[1]);
206 finish_connect(pid);
207 return ret;
208 }