git-rev-parse: pass on "--" flag when required
[git.git] / fetch-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "commit.h"
5 #include "tag.h"
6 #include <time.h>
7 #include <sys/wait.h>
8
9 static int quiet;
10 static int verbose;
11 static const char fetch_pack_usage[] =
12 "git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
13 static const char *exec = "git-upload-pack";
14
15 #define COMPLETE        (1U << 0)
16
17 static int find_common(int fd[2], unsigned char *result_sha1,
18                        struct ref *refs)
19 {
20         int fetching;
21         static char line[1000];
22         static char rev_command[1024];
23         int count = 0, flushes = 0, retval, rev_command_len;
24         FILE *revs;
25
26         strcpy(rev_command, "git-rev-list $(git-rev-parse --all)");
27         rev_command_len = strlen(rev_command);
28         fetching = 0;
29         for ( ; refs ; refs = refs->next) {
30                 unsigned char *remote = refs->old_sha1;
31                 struct object *o;
32
33                 /*
34                  * If that object is complete (i.e. it is an ancestor of a
35                  * local ref), we tell them we have it but do not have to
36                  * tell them about its ancestors, which they already know
37                  * about.
38                  *
39                  * We use lookup_object here because we are only
40                  * interested in the case we *know* the object is
41                  * reachable and we have already scanned it.
42                  */
43                 if (((o = lookup_object(remote)) != NULL) &&
44                     (o->flags & COMPLETE)) {
45                         struct commit_list *p;
46                         struct commit *commit =
47                                 (struct commit *) (o = deref_tag(o));
48                         if (!o)
49                                 goto repair;
50                         if (o->type != commit_type)
51                                 continue;
52                         p = commit->parents;
53                         while (p &&
54                                rev_command_len + 44 < sizeof(rev_command)) {
55                                 snprintf(rev_command + rev_command_len, 44,
56                                          " ^%s",
57                                          sha1_to_hex(p->item->object.sha1));
58                                 rev_command_len += 43;
59                                 p = p->next;
60                         }
61                         continue;
62                 }
63         repair:
64                 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
65                 fetching++;
66         }
67         packet_flush(fd[1]);
68         if (!fetching)
69                 return 1;
70
71         revs = popen(rev_command, "r");
72         if (!revs)
73                 die("unable to run 'git-rev-list'");
74
75         flushes = 1;
76         retval = -1;
77         while (fgets(line, sizeof(line), revs) != NULL) {
78                 unsigned char sha1[20];
79                 if (get_sha1_hex(line, sha1))
80                         die("git-fetch-pack: expected object name, got crud");
81                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
82                 if (verbose)
83                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
84                 if (!(31 & ++count)) {
85                         packet_flush(fd[1]);
86                         flushes++;
87
88                         /*
89                          * We keep one window "ahead" of the other side, and
90                          * will wait for an ACK only on the next one
91                          */
92                         if (count == 32)
93                                 continue;
94                         if (get_ack(fd[0], result_sha1)) {
95                                 flushes = 0;
96                                 retval = 0;
97                                 if (verbose)
98                                         fprintf(stderr, "got ack\n");
99                                 break;
100                         }
101                         flushes--;
102                 }
103         }
104         pclose(revs);
105         packet_write(fd[1], "done\n");
106         if (verbose)
107                 fprintf(stderr, "done\n");
108         while (flushes) {
109                 flushes--;
110                 if (get_ack(fd[0], result_sha1)) {
111                         if (verbose)
112                                 fprintf(stderr, "got ack\n");
113                         return 0;
114                 }
115         }
116         return retval;
117 }
118
119 static struct commit_list *complete = NULL;
120
121 static int mark_complete(const char *path, const unsigned char *sha1)
122 {
123         struct object *o = parse_object(sha1);
124
125         while (o && o->type == tag_type) {
126                 struct tag *t = (struct tag *) o;
127                 if (!t->tagged)
128                         break; /* broken repository */
129                 o->flags |= COMPLETE;
130                 o = parse_object(t->tagged->sha1);
131         }
132         if (o && o->type == commit_type) {
133                 struct commit *commit = (struct commit *)o;
134                 commit->object.flags |= COMPLETE;
135                 insert_by_date(commit, &complete);
136         }
137         return 0;
138 }
139
140 static void mark_recent_complete_commits(unsigned long cutoff)
141 {
142         while (complete && cutoff <= complete->item->date) {
143                 if (verbose)
144                         fprintf(stderr, "Marking %s as complete\n",
145                                 sha1_to_hex(complete->item->object.sha1));
146                 pop_most_recent_commit(&complete, COMPLETE);
147         }
148 }
149
150 static int everything_local(struct ref *refs)
151 {
152         struct ref *ref;
153         int retval;
154         unsigned long cutoff = 0;
155
156         track_object_refs = 0;
157         save_commit_buffer = 0;
158
159         for (ref = refs; ref; ref = ref->next) {
160                 struct object *o;
161
162                 o = parse_object(ref->old_sha1);
163                 if (!o)
164                         continue;
165
166                 /* We already have it -- which may mean that we were
167                  * in sync with the other side at some time after
168                  * that (it is OK if we guess wrong here).
169                  */
170                 if (o->type == commit_type) {
171                         struct commit *commit = (struct commit *)o;
172                         if (!cutoff || cutoff < commit->date)
173                                 cutoff = commit->date;
174                 }
175         }
176
177         for_each_ref(mark_complete);
178         if (cutoff)
179                 mark_recent_complete_commits(cutoff);
180
181         for (retval = 1; refs ; refs = refs->next) {
182                 const unsigned char *remote = refs->old_sha1;
183                 unsigned char local[20];
184                 struct object *o;
185
186                 o = parse_object(remote);
187                 if (!o || !(o->flags & COMPLETE)) {
188                         retval = 0;
189                         if (!verbose)
190                                 continue;
191                         fprintf(stderr,
192                                 "want %s (%s)\n", sha1_to_hex(remote),
193                                 refs->name);
194                         continue;
195                 }
196
197                 memcpy(refs->new_sha1, local, 20);
198                 if (!verbose)
199                         continue;
200                 fprintf(stderr,
201                         "already have %s (%s)\n", sha1_to_hex(remote),
202                         refs->name);
203         }
204         return retval;
205 }
206
207 static int fetch_pack(int fd[2], int nr_match, char **match)
208 {
209         struct ref *ref;
210         unsigned char sha1[20];
211         int status;
212         pid_t pid;
213
214         get_remote_heads(fd[0], &ref, nr_match, match, 1);
215         if (!ref) {
216                 packet_flush(fd[1]);
217                 die("no matching remote head");
218         }
219         if (everything_local(ref)) {
220                 packet_flush(fd[1]);
221                 goto all_done;
222         }
223         if (find_common(fd, sha1, ref) < 0)
224                 fprintf(stderr, "warning: no common commits\n");
225         pid = fork();
226         if (pid < 0)
227                 die("git-fetch-pack: unable to fork off git-unpack-objects");
228         if (!pid) {
229                 dup2(fd[0], 0);
230                 close(fd[0]);
231                 close(fd[1]);
232                 execlp("git-unpack-objects", "git-unpack-objects",
233                        quiet ? "-q" : NULL, NULL);
234                 die("git-unpack-objects exec failed");
235         }
236         close(fd[0]);
237         close(fd[1]);
238         while (waitpid(pid, &status, 0) < 0) {
239                 if (errno != EINTR)
240                         die("waiting for git-unpack-objects: %s", strerror(errno));
241         }
242         if (WIFEXITED(status)) {
243                 int code = WEXITSTATUS(status);
244                 if (code)
245                         die("git-unpack-objects died with error code %d", code);
246 all_done:
247                 while (ref) {
248                         printf("%s %s\n",
249                                sha1_to_hex(ref->old_sha1), ref->name);
250                         ref = ref->next;
251                 }
252                 return 0;
253         }
254         if (WIFSIGNALED(status)) {
255                 int sig = WTERMSIG(status);
256                 die("git-unpack-objects died of signal %d", sig);
257         }
258         die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
259 }
260
261 int main(int argc, char **argv)
262 {
263         int i, ret, nr_heads;
264         char *dest = NULL, **heads;
265         int fd[2];
266         pid_t pid;
267
268         nr_heads = 0;
269         heads = NULL;
270         for (i = 1; i < argc; i++) {
271                 char *arg = argv[i];
272
273                 if (*arg == '-') {
274                         if (!strncmp("--exec=", arg, 7)) {
275                                 exec = arg + 7;
276                                 continue;
277                         }
278                         if (!strcmp("-q", arg)) {
279                                 quiet = 1;
280                                 continue;
281                         }
282                         if (!strcmp("-v", arg)) {
283                                 verbose = 1;
284                                 continue;
285                         }
286                         usage(fetch_pack_usage);
287                 }
288                 dest = arg;
289                 heads = argv + i + 1;
290                 nr_heads = argc - i - 1;
291                 break;
292         }
293         if (!dest)
294                 usage(fetch_pack_usage);
295         pid = git_connect(fd, dest, exec);
296         if (pid < 0)
297                 return 1;
298         ret = fetch_pack(fd, nr_heads, heads);
299         close(fd[0]);
300         close(fd[1]);
301         finish_connect(pid);
302         return ret;
303 }