/
send-pack.c
334 lines (302 loc) · 7.37 KB
/
send-pack.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#include "pkt-line.h"
static const char send_pack_usage[] =
"git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
" --all and explicit <head> specification are mutually exclusive.";
static const char *exec = "git-receive-pack";
static int verbose = 0;
static int send_all = 0;
static int force_update = 0;
static int is_zero_sha1(const unsigned char *sha1)
{
int i;
for (i = 0; i < 20; i++) {
if (*sha1++)
return 0;
}
return 1;
}
static void exec_pack_objects(void)
{
static char *args[] = {
"git-pack-objects",
"--stdout",
NULL
};
execvp("git-pack-objects", args);
die("git-pack-objects exec failed (%s)", strerror(errno));
}
static void exec_rev_list(struct ref *refs)
{
static char *args[1000];
int i = 0;
args[i++] = "git-rev-list"; /* 0 */
args[i++] = "--objects"; /* 1 */
while (refs) {
char *buf = malloc(100);
if (i > 900)
die("git-rev-list environment overflow");
if (!is_zero_sha1(refs->old_sha1) &&
has_sha1_file(refs->old_sha1)) {
args[i++] = buf;
snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
buf += 50;
}
if (!is_zero_sha1(refs->new_sha1)) {
args[i++] = buf;
snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
}
refs = refs->next;
}
args[i] = NULL;
execvp("git-rev-list", args);
die("git-rev-list exec failed (%s)", strerror(errno));
}
static void rev_list(int fd, struct ref *refs)
{
int pipe_fd[2];
pid_t pack_objects_pid;
if (pipe(pipe_fd) < 0)
die("rev-list setup: pipe failed");
pack_objects_pid = fork();
if (!pack_objects_pid) {
dup2(pipe_fd[0], 0);
dup2(fd, 1);
close(pipe_fd[0]);
close(pipe_fd[1]);
close(fd);
exec_pack_objects();
die("pack-objects setup failed");
}
if (pack_objects_pid < 0)
die("pack-objects fork failed");
dup2(pipe_fd[1], 1);
close(pipe_fd[0]);
close(pipe_fd[1]);
close(fd);
exec_rev_list(refs);
}
static int pack_objects(int fd, struct ref *refs)
{
pid_t rev_list_pid;
rev_list_pid = fork();
if (!rev_list_pid) {
rev_list(fd, refs);
die("rev-list setup failed");
}
if (rev_list_pid < 0)
die("rev-list fork failed");
/*
* We don't wait for the rev-list pipeline in the parent:
* we end up waiting for the other end instead
*/
return 0;
}
static void unmark_and_free(struct commit_list *list, unsigned int mark)
{
while (list) {
struct commit_list *temp = list;
temp->item->object.flags &= ~mark;
list = temp->next;
free(temp);
}
}
static int ref_newer(const unsigned char *new_sha1,
const unsigned char *old_sha1)
{
struct object *o;
struct commit *old, *new;
struct commit_list *list, *used;
int found = 0;
/* Both new and old must be commit-ish and new is descendant of
* old. Otherwise we require --force.
*/
o = deref_tag(parse_object(old_sha1), NULL, 0);
if (!o || o->type != commit_type)
return 0;
old = (struct commit *) o;
o = deref_tag(parse_object(new_sha1), NULL, 0);
if (!o || o->type != commit_type)
return 0;
new = (struct commit *) o;
if (parse_commit(new) < 0)
return 0;
used = list = NULL;
commit_list_insert(new, &list);
while (list) {
new = pop_most_recent_commit(&list, 1);
commit_list_insert(new, &used);
if (new == old) {
found = 1;
break;
}
}
unmark_and_free(list, 1);
unmark_and_free(used, 1);
return found;
}
static struct ref *local_refs, **local_tail;
static struct ref *remote_refs, **remote_tail;
static int one_local_ref(const char *refname, const unsigned char *sha1)
{
struct ref *ref;
int len = strlen(refname) + 1;
ref = xcalloc(1, sizeof(*ref) + len);
memcpy(ref->new_sha1, sha1, 20);
memcpy(ref->name, refname, len);
*local_tail = ref;
local_tail = &ref->next;
return 0;
}
static void get_local_heads(void)
{
local_tail = &local_refs;
for_each_ref(one_local_ref);
}
static int send_pack(int in, int out, int nr_refspec, char **refspec)
{
struct ref *ref;
int new_refs;
int ret = 0;
/* No funny business with the matcher */
remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
get_local_heads();
/* match them up */
if (!remote_tail)
remote_tail = &remote_refs;
if (match_refs(local_refs, remote_refs, &remote_tail,
nr_refspec, refspec, send_all))
return -1;
if (!remote_refs) {
fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
return 0;
}
/*
* Finally, tell the other end!
*/
new_refs = 0;
for (ref = remote_refs; ref; ref = ref->next) {
char old_hex[60], *new_hex;
if (!ref->peer_ref)
continue;
if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
if (verbose)
fprintf(stderr, "'%s': up-to-date\n", ref->name);
continue;
}
/* This part determines what can overwrite what.
* The rules are:
*
* (0) you can always use --force or +A:B notation to
* selectively force individual ref pairs.
*
* (1) if the old thing does not exist, it is OK.
*
* (2) if you do not have the old thing, you are not allowed
* to overwrite it; you would not know what you are losing
* otherwise.
*
* (3) if both new and old are commit-ish, and new is a
* descendant of old, it is OK.
*/
if (!force_update &&
!is_zero_sha1(ref->old_sha1) &&
!ref->force) {
if (!has_sha1_file(ref->old_sha1)) {
error("remote '%s' object %s does not "
"exist on local",
ref->name, sha1_to_hex(ref->old_sha1));
ret = -2;
continue;
}
/* We assume that local is fsck-clean. Otherwise
* you _could_ have an old tag which points at
* something you do not have, which may or may not
* be a commit.
*/
if (!ref_newer(ref->peer_ref->new_sha1,
ref->old_sha1)) {
error("remote ref '%s' is not a strict "
"subset of local ref '%s'.", ref->name,
ref->peer_ref->name);
ret = -2;
continue;
}
}
memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
if (is_zero_sha1(ref->new_sha1)) {
error("cannot happen anymore");
ret = -3;
continue;
}
new_refs++;
strcpy(old_hex, sha1_to_hex(ref->old_sha1));
new_hex = sha1_to_hex(ref->new_sha1);
packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
fprintf(stderr, "updating '%s'", ref->name);
if (strcmp(ref->name, ref->peer_ref->name))
fprintf(stderr, " using '%s'", ref->peer_ref->name);
fprintf(stderr, "\n from %s\n to %s\n", old_hex, new_hex);
}
packet_flush(out);
if (new_refs)
pack_objects(out, remote_refs);
else if (ret == 0)
fprintf(stderr, "Everything up-to-date\n");
close(out);
return ret;
}
int main(int argc, char **argv)
{
int i, nr_heads = 0;
char *dest = NULL;
char **heads = NULL;
int fd[2], ret;
pid_t pid;
setup_git_directory();
argv++;
for (i = 1; i < argc; i++, argv++) {
char *arg = *argv;
if (*arg == '-') {
if (!strncmp(arg, "--exec=", 7)) {
exec = arg + 7;
continue;
}
if (!strcmp(arg, "--all")) {
send_all = 1;
continue;
}
if (!strcmp(arg, "--force")) {
force_update = 1;
continue;
}
if (!strcmp(arg, "--verbose")) {
verbose = 1;
continue;
}
usage(send_pack_usage);
}
if (!dest) {
dest = arg;
continue;
}
heads = argv;
nr_heads = argc - i;
break;
}
if (!dest)
usage(send_pack_usage);
if (heads && send_all)
usage(send_pack_usage);
pid = git_connect(fd, dest, exec);
if (pid < 0)
return 1;
ret = send_pack(fd[0], fd[1], nr_heads, heads);
close(fd[0]);
close(fd[1]);
finish_connect(pid);
return ret;
}