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