Store peeled refs in packed-refs (take 2).
[git] / upload-pack.c
1 #include <signal.h>
2 #include <sys/wait.h>
3 #include <sys/poll.h>
4 #include "cache.h"
5 #include "refs.h"
6 #include "pkt-line.h"
7 #include "sideband.h"
8 #include "tag.h"
9 #include "object.h"
10 #include "commit.h"
11 #include "exec_cmd.h"
12
13 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
14
15 #define THEY_HAVE (1U << 0)
16 #define OUR_REF (1U << 1)
17 #define WANTED (1U << 2)
18 static int multi_ack, nr_our_refs;
19 static int use_thin_pack, use_ofs_delta;
20 static struct object_array have_obj;
21 static struct object_array want_obj;
22 static unsigned int timeout;
23 /* 0 for no sideband,
24  * otherwise maximum packet size (up to 65520 bytes).
25  */
26 static int use_sideband;
27
28 static void reset_timeout(void)
29 {
30         alarm(timeout);
31 }
32
33 static int strip(char *line, int len)
34 {
35         if (len && line[len-1] == '\n')
36                 line[--len] = 0;
37         return len;
38 }
39
40 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
41 {
42         if (use_sideband)
43                 return send_sideband(1, fd, data, sz, use_sideband);
44         if (fd == 3)
45                 /* emergency quit */
46                 fd = 2;
47         if (fd == 2) {
48                 xwrite(fd, data, sz);
49                 return sz;
50         }
51         return safe_write(fd, data, sz);
52 }
53
54 static void create_pack_file(void)
55 {
56         /* Pipes between rev-list to pack-objects, pack-objects to us
57          * and pack-objects error stream for progress bar.
58          */
59         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
60         pid_t pid_rev_list, pid_pack_objects;
61         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
62         char data[8193], progress[128];
63         char abort_msg[] = "aborting due to possible repository "
64                 "corruption on the remote side.";
65         int buffered = -1;
66
67         if (pipe(lp_pipe) < 0)
68                 die("git-upload-pack: unable to create pipe");
69         pid_rev_list = fork();
70         if (pid_rev_list < 0)
71                 die("git-upload-pack: unable to fork git-rev-list");
72
73         if (!pid_rev_list) {
74                 int i;
75                 int args;
76                 const char **argv;
77                 const char **p;
78                 char *buf;
79
80                 if (create_full_pack) {
81                         args = 10;
82                         use_thin_pack = 0; /* no point doing it */
83                 }
84                 else
85                         args = have_obj.nr + want_obj.nr + 5;
86                 p = xmalloc(args * sizeof(char *));
87                 argv = (const char **) p;
88                 buf = xmalloc(args * 45);
89
90                 dup2(lp_pipe[1], 1);
91                 close(0);
92                 close(lp_pipe[0]);
93                 close(lp_pipe[1]);
94                 *p++ = "rev-list";
95                 *p++ = use_thin_pack ? "--objects-edge" : "--objects";
96                 if (create_full_pack)
97                         *p++ = "--all";
98                 else {
99                         for (i = 0; i < want_obj.nr; i++) {
100                                 struct object *o = want_obj.objects[i].item;
101                                 *p++ = buf;
102                                 memcpy(buf, sha1_to_hex(o->sha1), 41);
103                                 buf += 41;
104                         }
105                 }
106                 if (!create_full_pack)
107                         for (i = 0; i < have_obj.nr; i++) {
108                                 struct object *o = have_obj.objects[i].item;
109                                 *p++ = buf;
110                                 *buf++ = '^';
111                                 memcpy(buf, sha1_to_hex(o->sha1), 41);
112                                 buf += 41;
113                         }
114                 *p++ = NULL;
115                 execv_git_cmd(argv);
116                 die("git-upload-pack: unable to exec git-rev-list");
117         }
118
119         if (pipe(pu_pipe) < 0)
120                 die("git-upload-pack: unable to create pipe");
121         if (pipe(pe_pipe) < 0)
122                 die("git-upload-pack: unable to create pipe");
123         pid_pack_objects = fork();
124         if (pid_pack_objects < 0) {
125                 /* daemon sets things up to ignore TERM */
126                 kill(pid_rev_list, SIGKILL);
127                 die("git-upload-pack: unable to fork git-pack-objects");
128         }
129         if (!pid_pack_objects) {
130                 dup2(lp_pipe[0], 0);
131                 dup2(pu_pipe[1], 1);
132                 dup2(pe_pipe[1], 2);
133
134                 close(lp_pipe[0]);
135                 close(lp_pipe[1]);
136                 close(pu_pipe[0]);
137                 close(pu_pipe[1]);
138                 close(pe_pipe[0]);
139                 close(pe_pipe[1]);
140                 execl_git_cmd("pack-objects", "--stdout", "--progress",
141                               use_ofs_delta ? "--delta-base-offset" : NULL,
142                               NULL);
143                 kill(pid_rev_list, SIGKILL);
144                 die("git-upload-pack: unable to exec git-pack-objects");
145         }
146
147         close(lp_pipe[0]);
148         close(lp_pipe[1]);
149
150         /* We read from pe_pipe[0] to capture stderr output for
151          * progress bar, and pu_pipe[0] to capture the pack data.
152          */
153         close(pe_pipe[1]);
154         close(pu_pipe[1]);
155
156         while (1) {
157                 const char *who;
158                 struct pollfd pfd[2];
159                 pid_t pid;
160                 int status;
161                 ssize_t sz;
162                 int pe, pu, pollsize;
163
164                 reset_timeout();
165
166                 pollsize = 0;
167                 pe = pu = -1;
168
169                 if (0 <= pu_pipe[0]) {
170                         pfd[pollsize].fd = pu_pipe[0];
171                         pfd[pollsize].events = POLLIN;
172                         pu = pollsize;
173                         pollsize++;
174                 }
175                 if (0 <= pe_pipe[0]) {
176                         pfd[pollsize].fd = pe_pipe[0];
177                         pfd[pollsize].events = POLLIN;
178                         pe = pollsize;
179                         pollsize++;
180                 }
181
182                 if (pollsize) {
183                         if (poll(pfd, pollsize, -1) < 0) {
184                                 if (errno != EINTR) {
185                                         error("poll failed, resuming: %s",
186                                               strerror(errno));
187                                         sleep(1);
188                                 }
189                                 continue;
190                         }
191                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
192                                 /* Data ready; we keep the last byte
193                                  * to ourselves in case we detect
194                                  * broken rev-list, so that we can
195                                  * leave the stream corrupted.  This
196                                  * is unfortunate -- unpack-objects
197                                  * would happily accept a valid pack
198                                  * data with trailing garbage, so
199                                  * appending garbage after we pass all
200                                  * the pack data is not good enough to
201                                  * signal breakage to downstream.
202                                  */
203                                 char *cp = data;
204                                 ssize_t outsz = 0;
205                                 if (0 <= buffered) {
206                                         *cp++ = buffered;
207                                         outsz++;
208                                 }
209                                 sz = read(pu_pipe[0], cp,
210                                           sizeof(data) - outsz);
211                                 if (0 < sz)
212                                                 ;
213                                 else if (sz == 0) {
214                                         close(pu_pipe[0]);
215                                         pu_pipe[0] = -1;
216                                 }
217                                 else
218                                         goto fail;
219                                 sz += outsz;
220                                 if (1 < sz) {
221                                         buffered = data[sz-1] & 0xFF;
222                                         sz--;
223                                 }
224                                 else
225                                         buffered = -1;
226                                 sz = send_client_data(1, data, sz);
227                                 if (sz < 0)
228                                         goto fail;
229                         }
230                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
231                                 /* Status ready; we ship that in the side-band
232                                  * or dump to the standard error.
233                                  */
234                                 sz = read(pe_pipe[0], progress,
235                                           sizeof(progress));
236                                 if (0 < sz)
237                                         send_client_data(2, progress, sz);
238                                 else if (sz == 0) {
239                                         close(pe_pipe[0]);
240                                         pe_pipe[0] = -1;
241                                 }
242                                 else
243                                         goto fail;
244                         }
245                 }
246
247                 /* See if the children are still there */
248                 if (pid_rev_list || pid_pack_objects) {
249                         pid = waitpid(-1, &status, WNOHANG);
250                         if (!pid)
251                                 continue;
252                         who = ((pid == pid_rev_list) ? "git-rev-list" :
253                                (pid == pid_pack_objects) ? "git-pack-objects" :
254                                NULL);
255                         if (!who) {
256                                 if (pid < 0) {
257                                         error("git-upload-pack: %s",
258                                               strerror(errno));
259                                         goto fail;
260                                 }
261                                 error("git-upload-pack: we weren't "
262                                       "waiting for %d", pid);
263                                 continue;
264                         }
265                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
266                                 error("git-upload-pack: %s died with error.",
267                                       who);
268                                 goto fail;
269                         }
270                         if (pid == pid_rev_list)
271                                 pid_rev_list = 0;
272                         if (pid == pid_pack_objects)
273                                 pid_pack_objects = 0;
274                         if (pid_rev_list || pid_pack_objects)
275                                 continue;
276                 }
277
278                 /* both died happily */
279                 if (pollsize)
280                         continue;
281
282                 /* flush the data */
283                 if (0 <= buffered) {
284                         data[0] = buffered;
285                         sz = send_client_data(1, data, 1);
286                         if (sz < 0)
287                                 goto fail;
288                         fprintf(stderr, "flushed.\n");
289                 }
290                 if (use_sideband)
291                         packet_flush(1);
292                 return;
293         }
294  fail:
295         if (pid_pack_objects)
296                 kill(pid_pack_objects, SIGKILL);
297         if (pid_rev_list)
298                 kill(pid_rev_list, SIGKILL);
299         send_client_data(3, abort_msg, sizeof(abort_msg));
300         die("git-upload-pack: %s", abort_msg);
301 }
302
303 static int got_sha1(char *hex, unsigned char *sha1)
304 {
305         struct object *o;
306
307         if (get_sha1_hex(hex, sha1))
308                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
309         if (!has_sha1_file(sha1))
310                 return 0;
311
312         o = lookup_object(sha1);
313         if (!(o && o->parsed))
314                 o = parse_object(sha1);
315         if (!o)
316                 die("oops (%s)", sha1_to_hex(sha1));
317         if (o->type == OBJ_COMMIT) {
318                 struct commit_list *parents;
319                 if (o->flags & THEY_HAVE)
320                         return 0;
321                 o->flags |= THEY_HAVE;
322                 for (parents = ((struct commit*)o)->parents;
323                      parents;
324                      parents = parents->next)
325                         parents->item->object.flags |= THEY_HAVE;
326         }
327         add_object_array(o, NULL, &have_obj);
328         return 1;
329 }
330
331 static int get_common_commits(void)
332 {
333         static char line[1000];
334         unsigned char sha1[20];
335         char hex[41], last_hex[41];
336         int len;
337
338         track_object_refs = 0;
339         save_commit_buffer = 0;
340
341         for(;;) {
342                 len = packet_read_line(0, line, sizeof(line));
343                 reset_timeout();
344
345                 if (!len) {
346                         if (have_obj.nr == 0 || multi_ack)
347                                 packet_write(1, "NAK\n");
348                         continue;
349                 }
350                 len = strip(line, len);
351                 if (!strncmp(line, "have ", 5)) {
352                         if (got_sha1(line+5, sha1)) {
353                                 memcpy(hex, sha1_to_hex(sha1), 41);
354                                 if (multi_ack) {
355                                         const char *msg = "ACK %s continue\n";
356                                         packet_write(1, msg, hex);
357                                         memcpy(last_hex, hex, 41);
358                                 }
359                                 else if (have_obj.nr == 1)
360                                         packet_write(1, "ACK %s\n", hex);
361                         }
362                         continue;
363                 }
364                 if (!strcmp(line, "done")) {
365                         if (have_obj.nr > 0) {
366                                 if (multi_ack)
367                                         packet_write(1, "ACK %s\n", last_hex);
368                                 return 0;
369                         }
370                         packet_write(1, "NAK\n");
371                         return -1;
372                 }
373                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
374         }
375 }
376
377 static void receive_needs(void)
378 {
379         static char line[1000];
380         int len;
381
382         for (;;) {
383                 struct object *o;
384                 unsigned char sha1_buf[20];
385                 len = packet_read_line(0, line, sizeof(line));
386                 reset_timeout();
387                 if (!len)
388                         return;
389
390                 if (strncmp("want ", line, 5) ||
391                     get_sha1_hex(line+5, sha1_buf))
392                         die("git-upload-pack: protocol error, "
393                             "expected to get sha, not '%s'", line);
394                 if (strstr(line+45, "multi_ack"))
395                         multi_ack = 1;
396                 if (strstr(line+45, "thin-pack"))
397                         use_thin_pack = 1;
398                 if (strstr(line+45, "ofs-delta"))
399                         use_ofs_delta = 1;
400                 if (strstr(line+45, "side-band-64k"))
401                         use_sideband = LARGE_PACKET_MAX;
402                 else if (strstr(line+45, "side-band"))
403                         use_sideband = DEFAULT_PACKET_MAX;
404
405                 /* We have sent all our refs already, and the other end
406                  * should have chosen out of them; otherwise they are
407                  * asking for nonsense.
408                  *
409                  * Hmph.  We may later want to allow "want" line that
410                  * asks for something like "master~10" (symbolic)...
411                  * would it make sense?  I don't know.
412                  */
413                 o = lookup_object(sha1_buf);
414                 if (!o || !(o->flags & OUR_REF))
415                         die("git-upload-pack: not our ref %s", line+5);
416                 if (!(o->flags & WANTED)) {
417                         o->flags |= WANTED;
418                         add_object_array(o, NULL, &want_obj);
419                 }
420         }
421 }
422
423 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
424 {
425         static const char *capabilities = "multi_ack thin-pack side-band side-band-64k ofs-delta";
426         struct object *o = parse_object(sha1);
427
428         if (!o)
429                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
430
431         if (capabilities)
432                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
433                         0, capabilities);
434         else
435                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
436         capabilities = NULL;
437         if (!(o->flags & OUR_REF)) {
438                 o->flags |= OUR_REF;
439                 nr_our_refs++;
440         }
441         if (o->type == OBJ_TAG) {
442                 o = deref_tag(o, refname, 0);
443                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
444         }
445         return 0;
446 }
447
448 static void upload_pack(void)
449 {
450         reset_timeout();
451         head_ref(send_ref, NULL);
452         for_each_ref(send_ref, NULL);
453         packet_flush(1);
454         receive_needs();
455         if (want_obj.nr) {
456                 get_common_commits();
457                 create_pack_file();
458         }
459 }
460
461 int main(int argc, char **argv)
462 {
463         char *dir;
464         int i;
465         int strict = 0;
466
467         for (i = 1; i < argc; i++) {
468                 char *arg = argv[i];
469
470                 if (arg[0] != '-')
471                         break;
472                 if (!strcmp(arg, "--strict")) {
473                         strict = 1;
474                         continue;
475                 }
476                 if (!strncmp(arg, "--timeout=", 10)) {
477                         timeout = atoi(arg+10);
478                         continue;
479                 }
480                 if (!strcmp(arg, "--")) {
481                         i++;
482                         break;
483                 }
484         }
485         
486         if (i != argc-1)
487                 usage(upload_pack_usage);
488         dir = argv[i];
489
490         if (!enter_repo(dir, strict))
491                 die("'%s': unable to chdir or not a git archive", dir);
492
493         upload_pack();
494         return 0;
495 }