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