Teach bash about git log/show/whatchanged options.
[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 /* bits #0..7 in revision.h, #8..10 in commit.c */
16 #define THEY_HAVE       (1u << 11)
17 #define OUR_REF         (1u << 12)
18 #define WANTED          (1u << 13)
19 #define COMMON_KNOWN    (1u << 14)
20 #define REACHABLE       (1u << 15)
21
22 static unsigned long oldest_have;
23
24 static int multi_ack, nr_our_refs;
25 static int use_thin_pack, use_ofs_delta;
26 static struct object_array have_obj;
27 static struct object_array want_obj;
28 static unsigned int timeout;
29 /* 0 for no sideband,
30  * otherwise maximum packet size (up to 65520 bytes).
31  */
32 static int use_sideband;
33
34 static void reset_timeout(void)
35 {
36         alarm(timeout);
37 }
38
39 static int strip(char *line, int len)
40 {
41         if (len && line[len-1] == '\n')
42                 line[--len] = 0;
43         return len;
44 }
45
46 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
47 {
48         if (use_sideband)
49                 return send_sideband(1, fd, data, sz, use_sideband);
50         if (fd == 3)
51                 /* emergency quit */
52                 fd = 2;
53         if (fd == 2) {
54                 xwrite(fd, data, sz);
55                 return sz;
56         }
57         return safe_write(fd, data, sz);
58 }
59
60 static void create_pack_file(void)
61 {
62         /* Pipes between rev-list to pack-objects, pack-objects to us
63          * and pack-objects error stream for progress bar.
64          */
65         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
66         pid_t pid_rev_list, pid_pack_objects;
67         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
68         char data[8193], progress[128];
69         char abort_msg[] = "aborting due to possible repository "
70                 "corruption on the remote side.";
71         int buffered = -1;
72
73         if (pipe(lp_pipe) < 0)
74                 die("git-upload-pack: unable to create pipe");
75         pid_rev_list = fork();
76         if (pid_rev_list < 0)
77                 die("git-upload-pack: unable to fork git-rev-list");
78
79         if (!pid_rev_list) {
80                 int i;
81                 int args;
82                 const char **argv;
83                 const char **p;
84                 char *buf;
85
86                 if (create_full_pack) {
87                         args = 10;
88                         use_thin_pack = 0; /* no point doing it */
89                 }
90                 else
91                         args = have_obj.nr + want_obj.nr + 5;
92                 p = xmalloc(args * sizeof(char *));
93                 argv = (const char **) p;
94                 buf = xmalloc(args * 45);
95
96                 dup2(lp_pipe[1], 1);
97                 close(0);
98                 close(lp_pipe[0]);
99                 close(lp_pipe[1]);
100                 *p++ = "rev-list";
101                 *p++ = use_thin_pack ? "--objects-edge" : "--objects";
102                 if (create_full_pack)
103                         *p++ = "--all";
104                 else {
105                         for (i = 0; i < want_obj.nr; i++) {
106                                 struct object *o = want_obj.objects[i].item;
107                                 *p++ = buf;
108                                 memcpy(buf, sha1_to_hex(o->sha1), 41);
109                                 buf += 41;
110                         }
111                 }
112                 if (!create_full_pack)
113                         for (i = 0; i < have_obj.nr; i++) {
114                                 struct object *o = have_obj.objects[i].item;
115                                 *p++ = buf;
116                                 *buf++ = '^';
117                                 memcpy(buf, sha1_to_hex(o->sha1), 41);
118                                 buf += 41;
119                         }
120                 *p++ = NULL;
121                 execv_git_cmd(argv);
122                 die("git-upload-pack: unable to exec git-rev-list");
123         }
124
125         if (pipe(pu_pipe) < 0)
126                 die("git-upload-pack: unable to create pipe");
127         if (pipe(pe_pipe) < 0)
128                 die("git-upload-pack: unable to create pipe");
129         pid_pack_objects = fork();
130         if (pid_pack_objects < 0) {
131                 /* daemon sets things up to ignore TERM */
132                 kill(pid_rev_list, SIGKILL);
133                 die("git-upload-pack: unable to fork git-pack-objects");
134         }
135         if (!pid_pack_objects) {
136                 dup2(lp_pipe[0], 0);
137                 dup2(pu_pipe[1], 1);
138                 dup2(pe_pipe[1], 2);
139
140                 close(lp_pipe[0]);
141                 close(lp_pipe[1]);
142                 close(pu_pipe[0]);
143                 close(pu_pipe[1]);
144                 close(pe_pipe[0]);
145                 close(pe_pipe[1]);
146                 execl_git_cmd("pack-objects", "--stdout", "--progress",
147                               use_ofs_delta ? "--delta-base-offset" : NULL,
148                               NULL);
149                 kill(pid_rev_list, SIGKILL);
150                 die("git-upload-pack: unable to exec git-pack-objects");
151         }
152
153         close(lp_pipe[0]);
154         close(lp_pipe[1]);
155
156         /* We read from pe_pipe[0] to capture stderr output for
157          * progress bar, and pu_pipe[0] to capture the pack data.
158          */
159         close(pe_pipe[1]);
160         close(pu_pipe[1]);
161
162         while (1) {
163                 const char *who;
164                 struct pollfd pfd[2];
165                 pid_t pid;
166                 int status;
167                 ssize_t sz;
168                 int pe, pu, pollsize;
169
170                 reset_timeout();
171
172                 pollsize = 0;
173                 pe = pu = -1;
174
175                 if (0 <= pu_pipe[0]) {
176                         pfd[pollsize].fd = pu_pipe[0];
177                         pfd[pollsize].events = POLLIN;
178                         pu = pollsize;
179                         pollsize++;
180                 }
181                 if (0 <= pe_pipe[0]) {
182                         pfd[pollsize].fd = pe_pipe[0];
183                         pfd[pollsize].events = POLLIN;
184                         pe = pollsize;
185                         pollsize++;
186                 }
187
188                 if (pollsize) {
189                         if (poll(pfd, pollsize, -1) < 0) {
190                                 if (errno != EINTR) {
191                                         error("poll failed, resuming: %s",
192                                               strerror(errno));
193                                         sleep(1);
194                                 }
195                                 continue;
196                         }
197                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
198                                 /* Data ready; we keep the last byte
199                                  * to ourselves in case we detect
200                                  * broken rev-list, so that we can
201                                  * leave the stream corrupted.  This
202                                  * is unfortunate -- unpack-objects
203                                  * would happily accept a valid pack
204                                  * data with trailing garbage, so
205                                  * appending garbage after we pass all
206                                  * the pack data is not good enough to
207                                  * signal breakage to downstream.
208                                  */
209                                 char *cp = data;
210                                 ssize_t outsz = 0;
211                                 if (0 <= buffered) {
212                                         *cp++ = buffered;
213                                         outsz++;
214                                 }
215                                 sz = read(pu_pipe[0], cp,
216                                           sizeof(data) - outsz);
217                                 if (0 < sz)
218                                                 ;
219                                 else if (sz == 0) {
220                                         close(pu_pipe[0]);
221                                         pu_pipe[0] = -1;
222                                 }
223                                 else
224                                         goto fail;
225                                 sz += outsz;
226                                 if (1 < sz) {
227                                         buffered = data[sz-1] & 0xFF;
228                                         sz--;
229                                 }
230                                 else
231                                         buffered = -1;
232                                 sz = send_client_data(1, data, sz);
233                                 if (sz < 0)
234                                         goto fail;
235                         }
236                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
237                                 /* Status ready; we ship that in the side-band
238                                  * or dump to the standard error.
239                                  */
240                                 sz = read(pe_pipe[0], progress,
241                                           sizeof(progress));
242                                 if (0 < sz)
243                                         send_client_data(2, progress, sz);
244                                 else if (sz == 0) {
245                                         close(pe_pipe[0]);
246                                         pe_pipe[0] = -1;
247                                 }
248                                 else
249                                         goto fail;
250                         }
251                 }
252
253                 /* See if the children are still there */
254                 if (pid_rev_list || pid_pack_objects) {
255                         pid = waitpid(-1, &status, WNOHANG);
256                         if (!pid)
257                                 continue;
258                         who = ((pid == pid_rev_list) ? "git-rev-list" :
259                                (pid == pid_pack_objects) ? "git-pack-objects" :
260                                NULL);
261                         if (!who) {
262                                 if (pid < 0) {
263                                         error("git-upload-pack: %s",
264                                               strerror(errno));
265                                         goto fail;
266                                 }
267                                 error("git-upload-pack: we weren't "
268                                       "waiting for %d", pid);
269                                 continue;
270                         }
271                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
272                                 error("git-upload-pack: %s died with error.",
273                                       who);
274                                 goto fail;
275                         }
276                         if (pid == pid_rev_list)
277                                 pid_rev_list = 0;
278                         if (pid == pid_pack_objects)
279                                 pid_pack_objects = 0;
280                         if (pid_rev_list || pid_pack_objects)
281                                 continue;
282                 }
283
284                 /* both died happily */
285                 if (pollsize)
286                         continue;
287
288                 /* flush the data */
289                 if (0 <= buffered) {
290                         data[0] = buffered;
291                         sz = send_client_data(1, data, 1);
292                         if (sz < 0)
293                                 goto fail;
294                         fprintf(stderr, "flushed.\n");
295                 }
296                 if (use_sideband)
297                         packet_flush(1);
298                 return;
299         }
300  fail:
301         if (pid_pack_objects)
302                 kill(pid_pack_objects, SIGKILL);
303         if (pid_rev_list)
304                 kill(pid_rev_list, SIGKILL);
305         send_client_data(3, abort_msg, sizeof(abort_msg));
306         die("git-upload-pack: %s", abort_msg);
307 }
308
309 static int got_sha1(char *hex, unsigned char *sha1)
310 {
311         struct object *o;
312         int we_knew_they_have = 0;
313
314         if (get_sha1_hex(hex, sha1))
315                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
316         if (!has_sha1_file(sha1))
317                 return -1;
318
319         o = lookup_object(sha1);
320         if (!(o && o->parsed))
321                 o = parse_object(sha1);
322         if (!o)
323                 die("oops (%s)", sha1_to_hex(sha1));
324         if (o->type == OBJ_COMMIT) {
325                 struct commit_list *parents;
326                 struct commit *commit = (struct commit *)o;
327                 if (o->flags & THEY_HAVE)
328                         we_knew_they_have = 1;
329                 else
330                         o->flags |= THEY_HAVE;
331                 if (!oldest_have || (commit->date < oldest_have))
332                         oldest_have = commit->date;
333                 for (parents = commit->parents;
334                      parents;
335                      parents = parents->next)
336                         parents->item->object.flags |= THEY_HAVE;
337         }
338         if (!we_knew_they_have) {
339                 add_object_array(o, NULL, &have_obj);
340                 return 1;
341         }
342         return 0;
343 }
344
345 static int reachable(struct commit *want)
346 {
347         struct commit_list *work = NULL;
348
349         insert_by_date(want, &work);
350         while (work) {
351                 struct commit_list *list = work->next;
352                 struct commit *commit = work->item;
353                 free(work);
354                 work = list;
355
356                 if (commit->object.flags & THEY_HAVE) {
357                         want->object.flags |= COMMON_KNOWN;
358                         break;
359                 }
360                 if (!commit->object.parsed)
361                         parse_object(commit->object.sha1);
362                 if (commit->object.flags & REACHABLE)
363                         continue;
364                 commit->object.flags |= REACHABLE;
365                 if (commit->date < oldest_have)
366                         continue;
367                 for (list = commit->parents; list; list = list->next) {
368                         struct commit *parent = list->item;
369                         if (!(parent->object.flags & REACHABLE))
370                                 insert_by_date(parent, &work);
371                 }
372         }
373         want->object.flags |= REACHABLE;
374         clear_commit_marks(want, REACHABLE);
375         free_commit_list(work);
376         return (want->object.flags & COMMON_KNOWN);
377 }
378
379 static int ok_to_give_up(void)
380 {
381         int i;
382
383         if (!have_obj.nr)
384                 return 0;
385
386         for (i = 0; i < want_obj.nr; i++) {
387                 struct object *want = want_obj.objects[i].item;
388
389                 if (want->flags & COMMON_KNOWN)
390                         continue;
391                 want = deref_tag(want, "a want line", 0);
392                 if (!want || want->type != OBJ_COMMIT) {
393                         /* no way to tell if this is reachable by
394                          * looking at the ancestry chain alone, so
395                          * leave a note to ourselves not to worry about
396                          * this object anymore.
397                          */
398                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
399                         continue;
400                 }
401                 if (!reachable((struct commit *)want))
402                         return 0;
403         }
404         return 1;
405 }
406
407 static int get_common_commits(void)
408 {
409         static char line[1000];
410         unsigned char sha1[20];
411         char hex[41], last_hex[41];
412         int len;
413
414         track_object_refs = 0;
415         save_commit_buffer = 0;
416
417         for(;;) {
418                 len = packet_read_line(0, line, sizeof(line));
419                 reset_timeout();
420
421                 if (!len) {
422                         if (have_obj.nr == 0 || multi_ack)
423                                 packet_write(1, "NAK\n");
424                         continue;
425                 }
426                 len = strip(line, len);
427                 if (!strncmp(line, "have ", 5)) {
428                         switch (got_sha1(line+5, sha1)) {
429                         case -1: /* they have what we do not */
430                                 if (multi_ack && ok_to_give_up())
431                                         packet_write(1, "ACK %s continue\n",
432                                                      sha1_to_hex(sha1));
433                                 break;
434                         default:
435                                 memcpy(hex, sha1_to_hex(sha1), 41);
436                                 if (multi_ack) {
437                                         const char *msg = "ACK %s continue\n";
438                                         packet_write(1, msg, hex);
439                                         memcpy(last_hex, hex, 41);
440                                 }
441                                 else if (have_obj.nr == 1)
442                                         packet_write(1, "ACK %s\n", hex);
443                                 break;
444                         }
445                         continue;
446                 }
447                 if (!strcmp(line, "done")) {
448                         if (have_obj.nr > 0) {
449                                 if (multi_ack)
450                                         packet_write(1, "ACK %s\n", last_hex);
451                                 return 0;
452                         }
453                         packet_write(1, "NAK\n");
454                         return -1;
455                 }
456                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
457         }
458 }
459
460 static void receive_needs(void)
461 {
462         static char line[1000];
463         int len;
464
465         for (;;) {
466                 struct object *o;
467                 unsigned char sha1_buf[20];
468                 len = packet_read_line(0, line, sizeof(line));
469                 reset_timeout();
470                 if (!len)
471                         return;
472
473                 if (strncmp("want ", line, 5) ||
474                     get_sha1_hex(line+5, sha1_buf))
475                         die("git-upload-pack: protocol error, "
476                             "expected to get sha, not '%s'", line);
477                 if (strstr(line+45, "multi_ack"))
478                         multi_ack = 1;
479                 if (strstr(line+45, "thin-pack"))
480                         use_thin_pack = 1;
481                 if (strstr(line+45, "ofs-delta"))
482                         use_ofs_delta = 1;
483                 if (strstr(line+45, "side-band-64k"))
484                         use_sideband = LARGE_PACKET_MAX;
485                 else if (strstr(line+45, "side-band"))
486                         use_sideband = DEFAULT_PACKET_MAX;
487
488                 /* We have sent all our refs already, and the other end
489                  * should have chosen out of them; otherwise they are
490                  * asking for nonsense.
491                  *
492                  * Hmph.  We may later want to allow "want" line that
493                  * asks for something like "master~10" (symbolic)...
494                  * would it make sense?  I don't know.
495                  */
496                 o = lookup_object(sha1_buf);
497                 if (!o || !(o->flags & OUR_REF))
498                         die("git-upload-pack: not our ref %s", line+5);
499                 if (!(o->flags & WANTED)) {
500                         o->flags |= WANTED;
501                         add_object_array(o, NULL, &want_obj);
502                 }
503         }
504 }
505
506 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
507 {
508         static const char *capabilities = "multi_ack thin-pack side-band side-band-64k ofs-delta";
509         struct object *o = parse_object(sha1);
510
511         if (!o)
512                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
513
514         if (capabilities)
515                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
516                         0, capabilities);
517         else
518                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
519         capabilities = NULL;
520         if (!(o->flags & OUR_REF)) {
521                 o->flags |= OUR_REF;
522                 nr_our_refs++;
523         }
524         if (o->type == OBJ_TAG) {
525                 o = deref_tag(o, refname, 0);
526                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
527         }
528         return 0;
529 }
530
531 static void upload_pack(void)
532 {
533         reset_timeout();
534         head_ref(send_ref, NULL);
535         for_each_ref(send_ref, NULL);
536         packet_flush(1);
537         receive_needs();
538         if (want_obj.nr) {
539                 get_common_commits();
540                 create_pack_file();
541         }
542 }
543
544 int main(int argc, char **argv)
545 {
546         char *dir;
547         int i;
548         int strict = 0;
549
550         for (i = 1; i < argc; i++) {
551                 char *arg = argv[i];
552
553                 if (arg[0] != '-')
554                         break;
555                 if (!strcmp(arg, "--strict")) {
556                         strict = 1;
557                         continue;
558                 }
559                 if (!strncmp(arg, "--timeout=", 10)) {
560                         timeout = atoi(arg+10);
561                         continue;
562                 }
563                 if (!strcmp(arg, "--")) {
564                         i++;
565                         break;
566                 }
567         }
568         
569         if (i != argc-1)
570                 usage(upload_pack_usage);
571         dir = argv[i];
572
573         if (!enter_repo(dir, strict))
574                 die("'%s': unable to chdir or not a git archive", dir);
575
576         upload_pack();
577         return 0;
578 }