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