send-pack.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "tag.h"
   4 #include "refs.h"
   5 #include "pkt-line.h"
   6 #include "exec_cmd.h"
   7
   8 static const char send_pack_usage[] =
   9 "git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
  10 "  --all and explicit <head> specification are mutually exclusive.";
  11 static const char *exec = "git-receive-pack";
  12 static int verbose = 0;
  13 static int send_all = 0;
  14 static int force_update = 0;
  15 static int use_thin_pack = 0;
  16
  17 static int is_zero_sha1(const unsigned char *sha1)
  18 {
  19         int i;
  20
  21         for (i = 0; i < 20; i++) {
  22                 if (*sha1++)
  23                         return 0;
  24         }
  25         return 1;
  26 }
  27
  28 static void exec_pack_objects(void)
  29 {
  30         static const char *args[] = {
  31                 "pack-objects",
  32                 "--stdout",
  33                 NULL
  34         };
  35         execv_git_cmd(args);
  36         die("git-pack-objects exec failed (%s)", strerror(errno));
  37 }
  38
  39 static void exec_rev_list(struct ref *refs)
  40 {
  41         struct ref *ref;
  42         static const char *args[1000];
  43         int i = 0, j;
  44
  45         args[i++] = "rev-list"; /* 0 */
  46         if (use_thin_pack)      /* 1 */
  47                 args[i++] = "--objects-edge";
  48         else
  49                 args[i++] = "--objects";
  50
  51         /* First send the ones we care about most */
  52         for (ref = refs; ref; ref = ref->next) {
  53                 if (900 < i)
  54                         die("git-rev-list environment overflow");
  55                 if (!is_zero_sha1(ref->new_sha1)) {
  56                         char *buf = malloc(100);
  57                         args[i++] = buf;
  58                         snprintf(buf, 50, "%s", sha1_to_hex(ref->new_sha1));
  59                         buf += 50;
  60                         if (!is_zero_sha1(ref->old_sha1) &&
  61                             has_sha1_file(ref->old_sha1)) {
  62                                 args[i++] = buf;
  63                                 snprintf(buf, 50, "^%s",
  64                                          sha1_to_hex(ref->old_sha1));
  65                         }
  66                 }
  67         }
  68
  69         /* Then a handful of the remainder
  70          * NEEDSWORK: we would be better off if used the newer ones first.
  71          */
  72         for (ref = refs, j = i + 16;
  73              i < 900 && i < j && ref;
  74              ref = ref->next) {
  75                 if (is_zero_sha1(ref->new_sha1) &&
  76                     !is_zero_sha1(ref->old_sha1) &&
  77                     has_sha1_file(ref->old_sha1)) {
  78                         char *buf = malloc(42);
  79                         args[i++] = buf;
  80                         snprintf(buf, 42, "^%s", sha1_to_hex(ref->old_sha1));
  81                 }
  82         }
  83         args[i] = NULL;
  84         execv_git_cmd(args);
  85         die("git-rev-list exec failed (%s)", strerror(errno));
  86 }
  87
  88 static void rev_list(int fd, struct ref *refs)
  89 {
  90         int pipe_fd[2];
  91         pid_t pack_objects_pid;
  92
  93         if (pipe(pipe_fd) < 0)
  94                 die("rev-list setup: pipe failed");
  95         pack_objects_pid = fork();
  96         if (!pack_objects_pid) {
  97                 dup2(pipe_fd[0], 0);
  98                 dup2(fd, 1);
  99                 close(pipe_fd[0]);
 100                 close(pipe_fd[1]);
 101                 close(fd);
 102                 exec_pack_objects();
 103                 die("pack-objects setup failed");
 104         }
 105         if (pack_objects_pid < 0)
 106                 die("pack-objects fork failed");
 107         dup2(pipe_fd[1], 1);
 108         close(pipe_fd[0]);
 109         close(pipe_fd[1]);
 110         close(fd);
 111         exec_rev_list(refs);
 112 }
 113
 114 static int pack_objects(int fd, struct ref *refs)
 115 {
 116         pid_t rev_list_pid;
 117
 118         rev_list_pid = fork();
 119         if (!rev_list_pid) {
 120                 rev_list(fd, refs);
 121                 die("rev-list setup failed");
 122         }
 123         if (rev_list_pid < 0)
 124                 die("rev-list fork failed");
 125         /*
 126          * We don't wait for the rev-list pipeline in the parent:
 127          * we end up waiting for the other end instead
 128          */
 129         return 0;
 130 }
 131
 132 static void unmark_and_free(struct commit_list *list, unsigned int mark)
 133 {
 134         while (list) {
 135                 struct commit_list *temp = list;
 136                 temp->item->object.flags &= ~mark;
 137                 list = temp->next;
 138                 free(temp);
 139         }
 140 }
 141
 142 static int ref_newer(const unsigned char *new_sha1,
 143                      const unsigned char *old_sha1)
 144 {
 145         struct object *o;
 146         struct commit *old, *new;
 147         struct commit_list *list, *used;
 148         int found = 0;
 149
 150         /* Both new and old must be commit-ish and new is descendant of
 151          * old.  Otherwise we require --force.
 152          */
 153         o = deref_tag(parse_object(old_sha1), NULL, 0);
 154         if (!o || o->type != commit_type)
 155                 return 0;
 156         old = (struct commit *) o;
 157
 158         o = deref_tag(parse_object(new_sha1), NULL, 0);
 159         if (!o || o->type != commit_type)
 160                 return 0;
 161         new = (struct commit *) o;
 162
 163         if (parse_commit(new) < 0)
 164                 return 0;
 165
 166         used = list = NULL;
 167         commit_list_insert(new, &list);
 168         while (list) {
 169                 new = pop_most_recent_commit(&list, 1);
 170                 commit_list_insert(new, &used);
 171                 if (new == old) {
 172                         found = 1;
 173                         break;
 174                 }
 175         }
 176         unmark_and_free(list, 1);
 177         unmark_and_free(used, 1);
 178         return found;
 179 }
 180
 181 static struct ref *local_refs, **local_tail;
 182 static struct ref *remote_refs, **remote_tail;
 183
 184 static int one_local_ref(const char *refname, const unsigned char *sha1)
 185 {
 186         struct ref *ref;
 187         int len = strlen(refname) + 1;
 188         ref = xcalloc(1, sizeof(*ref) + len);
 189         memcpy(ref->new_sha1, sha1, 20);
 190         memcpy(ref->name, refname, len);
 191         *local_tail = ref;
 192         local_tail = &ref->next;
 193         return 0;
 194 }
 195
 196 static void get_local_heads(void)
 197 {
 198         local_tail = &local_refs;
 199         for_each_ref(one_local_ref);
 200 }
 201
 202 static int receive_status(int in)
 203 {
 204         char line[1000];
 205         int ret = 0;
 206         int len = packet_read_line(in, line, sizeof(line));
 207         if (len < 10 || memcmp(line, "unpack ", 7)) {
 208                 fprintf(stderr, "did not receive status back\n");
 209                 return -1;
 210         }
 211         if (memcmp(line, "unpack ok\n", 10)) {
 212                 fputs(line, stderr);
 213                 ret = -1;
 214         }
 215         while (1) {
 216                 len = packet_read_line(in, line, sizeof(line));
 217                 if (!len)
 218                         break;
 219                 if (len < 3 ||
 220                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 221                         fprintf(stderr, "protocol error: %s\n", line);
 222                         ret = -1;
 223                         break;
 224                 }
 225                 if (!memcmp(line, "ok", 2))
 226                         continue;
 227                 fputs(line, stderr);
 228                 ret = -1;
 229         }
 230         return ret;
 231 }
 232
 233 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 234 {
 235         struct ref *ref;
 236         int new_refs;
 237         int ret = 0;
 238         int ask_for_status_report = 0;
 239         int expect_status_report = 0;
 240
 241         /* No funny business with the matcher */
 242         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
 243         get_local_heads();
 244
 245         /* Does the other end support the reporting? */
 246         if (server_supports("report-status"))
 247                 ask_for_status_report = 1;
 248
 249         /* match them up */
 250         if (!remote_tail)
 251                 remote_tail = &remote_refs;
 252         if (match_refs(local_refs, remote_refs, &remote_tail,
 253                        nr_refspec, refspec, send_all))
 254                 return -1;
 255
 256         if (!remote_refs) {
 257                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 258                 return 0;
 259         }
 260
 261         /*
 262          * Finally, tell the other end!
 263          */
 264         new_refs = 0;
 265         for (ref = remote_refs; ref; ref = ref->next) {
 266                 char old_hex[60], *new_hex;
 267                 if (!ref->peer_ref)
 268                         continue;
 269                 if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
 270                         if (verbose)
 271                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 272                         continue;
 273                 }
 274
 275                 /* This part determines what can overwrite what.
 276                  * The rules are:
 277                  *
 278                  * (0) you can always use --force or +A:B notation to
 279                  *     selectively force individual ref pairs.
 280                  *
 281                  * (1) if the old thing does not exist, it is OK.
 282                  *
 283                  * (2) if you do not have the old thing, you are not allowed
 284                  *     to overwrite it; you would not know what you are losing
 285                  *     otherwise.
 286                  *
 287                  * (3) if both new and old are commit-ish, and new is a
 288                  *     descendant of old, it is OK.
 289                  */
 290
 291                 if (!force_update &&
 292                     !is_zero_sha1(ref->old_sha1) &&
 293                     !ref->force) {
 294                         if (!has_sha1_file(ref->old_sha1) ||
 295                             !ref_newer(ref->peer_ref->new_sha1,
 296                                        ref->old_sha1)) {
 297                                 /* We do not have the remote ref, or
 298                                  * we know that the remote ref is not
 299                                  * an ancestor of what we are trying to
 300                                  * push.  Either way this can be losing
 301                                  * commits at the remote end and likely
 302                                  * we were not up to date to begin with.
 303                                  */
 304                                 error("remote '%s' is not a strict "
 305                                       "subset of local ref '%s'. "
 306                                       "maybe you are not up-to-date and "
 307                                       "need to pull first?",
 308                                       ref->name,
 309                                       ref->peer_ref->name);
 310                                 ret = -2;
 311                                 continue;
 312                         }
 313                 }
 314                 memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
 315                 if (is_zero_sha1(ref->new_sha1)) {
 316                         error("cannot happen anymore");
 317                         ret = -3;
 318                         continue;
 319                 }
 320                 new_refs++;
 321                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 322                 new_hex = sha1_to_hex(ref->new_sha1);
 323
 324                 if (ask_for_status_report) {
 325                         packet_write(out, "%s %s %s%c%s",
 326                                      old_hex, new_hex, ref->name, 0,
 327                                      "report-status");
 328                         ask_for_status_report = 0;
 329                         expect_status_report = 1;
 330                 }
 331                 else
 332                         packet_write(out, "%s %s %s",
 333                                      old_hex, new_hex, ref->name);
 334                 fprintf(stderr, "updating '%s'", ref->name);
 335                 if (strcmp(ref->name, ref->peer_ref->name))
 336                         fprintf(stderr, " using '%s'", ref->peer_ref->name);
 337                 fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 338         }
 339
 340         packet_flush(out);
 341         if (new_refs)
 342                 pack_objects(out, remote_refs);
 343         close(out);
 344
 345         if (expect_status_report) {
 346                 if (receive_status(in))
 347                         ret = -4;
 348         }
 349
 350         if (!new_refs && ret == 0)
 351                 fprintf(stderr, "Everything up-to-date\n");
 352         return ret;
 353 }
 354
 355
 356 int main(int argc, char **argv)
 357 {
 358         int i, nr_heads = 0;
 359         char *dest = NULL;
 360         char **heads = NULL;
 361         int fd[2], ret;
 362         pid_t pid;
 363
 364         setup_git_directory();
 365         argv++;
 366         for (i = 1; i < argc; i++, argv++) {
 367                 char *arg = *argv;
 368
 369                 if (*arg == '-') {
 370                         if (!strncmp(arg, "--exec=", 7)) {
 371                                 exec = arg + 7;
 372                                 continue;
 373                         }
 374                         if (!strcmp(arg, "--all")) {
 375                                 send_all = 1;
 376                                 continue;
 377                         }
 378                         if (!strcmp(arg, "--force")) {
 379                                 force_update = 1;
 380                                 continue;
 381                         }
 382                         if (!strcmp(arg, "--verbose")) {
 383                                 verbose = 1;
 384                                 continue;
 385                         }
 386                         if (!strcmp(arg, "--thin")) {
 387                                 use_thin_pack = 1;
 388                                 continue;
 389                         }
 390                         usage(send_pack_usage);
 391                 }
 392                 if (!dest) {
 393                         dest = arg;
 394                         continue;
 395                 }
 396                 heads = argv;
 397                 nr_heads = argc - i;
 398                 break;
 399         }
 400         if (!dest)
 401                 usage(send_pack_usage);
 402         if (heads && send_all)
 403                 usage(send_pack_usage);
 404         pid = git_connect(fd, dest, exec);
 405         if (pid < 0)
 406                 return 1;
 407         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 408         close(fd[0]);
 409         close(fd[1]);
 410         finish_connect(pid);
 411         return ret;
 412 }