git-am: make it easier after fixing up an unapplicable patch.
[git/gitweb.git] / fetch-pack.c
blob8566ab1744b029e9696976e78bac4d48d2324129
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>
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";
15 #define COMPLETE (1U << 0)
17 static int find_common(int fd[2], unsigned char *result_sha1,
18 struct ref *refs)
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;
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;
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.
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.
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;
61 continue;
63 repair:
64 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
65 fetching++;
67 packet_flush(fd[1]);
68 if (!fetching)
69 return 1;
71 revs = popen(rev_command, "r");
72 if (!revs)
73 die("unable to run 'git-rev-list'");
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++;
89 * We keep one window "ahead" of the other side, and
90 * will wait for an ACK only on the next one
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;
101 flushes--;
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;
116 return retval;
119 static struct commit_list *complete = NULL;
121 static int mark_complete(const char *path, const unsigned char *sha1)
123 struct object *o = parse_object(sha1);
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);
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);
137 return 0;
140 static void mark_recent_complete_commits(unsigned long cutoff)
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);
150 static int everything_local(struct ref *refs)
152 struct ref *ref;
153 int retval;
154 unsigned long cutoff = 0;
156 track_object_refs = 0;
157 save_commit_buffer = 0;
159 for (ref = refs; ref; ref = ref->next) {
160 struct object *o;
162 o = parse_object(ref->old_sha1);
163 if (!o)
164 continue;
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).
170 if (o->type == commit_type) {
171 struct commit *commit = (struct commit *)o;
172 if (!cutoff || cutoff < commit->date)
173 cutoff = commit->date;
177 for_each_ref(mark_complete);
178 if (cutoff)
179 mark_recent_complete_commits(cutoff);
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;
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;
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);
204 return retval;
207 static int fetch_pack(int fd[2], int nr_match, char **match)
209 struct ref *ref;
210 unsigned char sha1[20];
211 int status;
212 pid_t pid;
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");
219 if (everything_local(ref)) {
220 packet_flush(fd[1]);
221 goto all_done;
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");
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));
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;
252 return 0;
254 if (WIFSIGNALED(status)) {
255 int sig = WTERMSIG(status);
256 die("git-unpack-objects died of signal %d", sig);
258 die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
261 int main(int argc, char **argv)
263 int i, ret, nr_heads;
264 char *dest = NULL, **heads;
265 int fd[2];
266 pid_t pid;
268 nr_heads = 0;
269 heads = NULL;
270 for (i = 1; i < argc; i++) {
271 char *arg = argv[i];
273 if (*arg == '-') {
274 if (!strncmp("--exec=", arg, 7)) {
275 exec = arg + 7;
276 continue;
278 if (!strcmp("-q", arg)) {
279 quiet = 1;
280 continue;
282 if (!strcmp("-v", arg)) {
283 verbose = 1;
284 continue;
286 usage(fetch_pack_usage);
288 dest = arg;
289 heads = argv + i + 1;
290 nr_heads = argc - i - 1;
291 break;
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;