send-pack.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "refs.h"
   4 #include "pkt-line.h"
   5
   6 static const char send_pack_usage[] =
   7 "git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
   8 "  --all and explicit <head> specification are mutually exclusive.";
   9 static const char *exec = "git-receive-pack";
  10 static int send_all = 0;
  11 static int force_update = 0;
  12
  13 static int is_zero_sha1(const unsigned char *sha1)
  14 {
  15         int i;
  16
  17         for (i = 0; i < 20; i++) {
  18                 if (*sha1++)
  19                         return 0;
  20         }
  21         return 1;
  22 }
  23
  24 static void exec_pack_objects(void)
  25 {
  26         static char *args[] = {
  27                 "git-pack-objects",
  28                 "--stdout",
  29                 NULL
  30         };
  31         execvp("git-pack-objects", args);
  32         die("git-pack-objects exec failed (%s)", strerror(errno));
  33 }
  34
  35 static void exec_rev_list(struct ref *refs)
  36 {
  37         static char *args[1000];
  38         int i = 0;
  39
  40         args[i++] = "git-rev-list";     /* 0 */
  41         args[i++] = "--objects";        /* 1 */
  42         while (refs) {
  43                 char *buf = malloc(100);
  44                 if (i > 900)
  45                         die("git-rev-list environment overflow");
  46                 if (!is_zero_sha1(refs->old_sha1) &&
  47                     has_sha1_file(refs->old_sha1)) {
  48                         args[i++] = buf;
  49                         snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  50                         buf += 50;
  51                 }
  52                 if (!is_zero_sha1(refs->new_sha1)) {
  53                         args[i++] = buf;
  54                         snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  55                 }
  56                 refs = refs->next;
  57         }
  58         args[i] = NULL;
  59         execvp("git-rev-list", args);
  60         die("git-rev-list exec failed (%s)", strerror(errno));
  61 }
  62
  63 static void rev_list(int fd, struct ref *refs)
  64 {
  65         int pipe_fd[2];
  66         pid_t pack_objects_pid;
  67
  68         if (pipe(pipe_fd) < 0)
  69                 die("rev-list setup: pipe failed");
  70         pack_objects_pid = fork();
  71         if (!pack_objects_pid) {
  72                 dup2(pipe_fd[0], 0);
  73                 dup2(fd, 1);
  74                 close(pipe_fd[0]);
  75                 close(pipe_fd[1]);
  76                 close(fd);
  77                 exec_pack_objects();
  78                 die("pack-objects setup failed");
  79         }
  80         if (pack_objects_pid < 0)
  81                 die("pack-objects fork failed");
  82         dup2(pipe_fd[1], 1);
  83         close(pipe_fd[0]);
  84         close(pipe_fd[1]);
  85         close(fd);
  86         exec_rev_list(refs);
  87 }
  88
  89 static int pack_objects(int fd, struct ref *refs)
  90 {
  91         pid_t rev_list_pid;
  92
  93         rev_list_pid = fork();
  94         if (!rev_list_pid) {
  95                 rev_list(fd, refs);
  96                 die("rev-list setup failed");
  97         }
  98         if (rev_list_pid < 0)
  99                 die("rev-list fork failed");
 100         /*
 101          * We don't wait for the rev-list pipeline in the parent:
 102          * we end up waiting for the other end instead
 103          */
 104         return 0;
 105 }
 106
 107 static int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 108 {
 109         struct commit *new, *old;
 110         struct commit_list *list;
 111
 112         if (force_update)
 113                 return 1;
 114         old = lookup_commit_reference(old_sha1);
 115         if (!old)
 116                 return 0;
 117         new = lookup_commit_reference(new_sha1);
 118         if (!new)
 119                 return 0;
 120         if (parse_commit(new) < 0)
 121                 return 0;
 122         list = NULL;
 123         commit_list_insert(new, &list);
 124         while (list) {
 125                 new = pop_most_recent_commit(&list, 1);
 126                 if (new == old)
 127                         return 1;
 128         }
 129         return 0;
 130 }
 131
 132 static struct ref *local_refs, **local_tail;
 133 static struct ref *remote_refs, **remote_tail;
 134
 135 static int one_local_ref(const char *refname, const unsigned char *sha1)
 136 {
 137         struct ref *ref;
 138         int len = strlen(refname) + 1;
 139         ref = xcalloc(1, sizeof(*ref) + len);
 140         memcpy(ref->new_sha1, sha1, 20);
 141         memcpy(ref->name, refname, len);
 142         *local_tail = ref;
 143         local_tail = &ref->next;
 144         return 0;
 145 }
 146
 147 static void get_local_heads(void)
 148 {
 149         local_tail = &local_refs;
 150         for_each_ref(one_local_ref);
 151 }
 152
 153 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 154 {
 155         struct ref *ref;
 156         int new_refs;
 157
 158         /* No funny business with the matcher */
 159         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL);
 160         get_local_heads();
 161
 162         /* match them up */
 163         if (!remote_tail)
 164                 remote_tail = &remote_refs;
 165         if (match_refs(local_refs, remote_refs, &remote_tail,
 166                        nr_refspec, refspec, send_all))
 167                 return -1;
 168         /*
 169          * Finally, tell the other end!
 170          */
 171         new_refs = 0;
 172         for (ref = remote_refs; ref; ref = ref->next) {
 173                 char old_hex[60], *new_hex;
 174                 if (!ref->peer_ref)
 175                         continue;
 176                 if (!is_zero_sha1(ref->old_sha1)) {
 177                         if (!has_sha1_file(ref->old_sha1)) {
 178                                 error("remote '%s' object %s does not "
 179                                       "exist on local",
 180                                       ref->name, sha1_to_hex(ref->old_sha1));
 181                                 continue;
 182                         }
 183                         if (!ref_newer(ref->peer_ref->new_sha1,
 184                                        ref->old_sha1)) {
 185                                 error("remote ref '%s' is not a strict "
 186                                       "subset of local ref '%s'.", ref->name,
 187                                       ref->peer_ref->name);
 188                                 continue;
 189                         }
 190                 }
 191                 if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
 192                         fprintf(stderr, "'%s': up-to-date\n", ref->name);
 193                         continue;
 194                 }
 195                 memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
 196                 if (is_zero_sha1(ref->new_sha1)) {
 197                         error("cannot happen anymore");
 198                         continue;
 199                 }
 200                 new_refs++;
 201                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 202                 new_hex = sha1_to_hex(ref->new_sha1);
 203                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 204                 fprintf(stderr, "updating '%s'", ref->name);
 205                 if (strcmp(ref->name, ref->peer_ref->name))
 206                         fprintf(stderr, " using '%s'", ref->peer_ref->name);
 207                 fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 208         }
 209
 210         packet_flush(out);
 211         if (new_refs)
 212                 pack_objects(out, remote_refs);
 213         close(out);
 214         return 0;
 215 }
 216
 217
 218 int main(int argc, char **argv)
 219 {
 220         int i, nr_heads = 0;
 221         char *dest = NULL;
 222         char **heads = NULL;
 223         int fd[2], ret;
 224         pid_t pid;
 225
 226         argv++;
 227         for (i = 1; i < argc; i++, argv++) {
 228                 char *arg = *argv;
 229
 230                 if (*arg == '-') {
 231                         if (!strncmp(arg, "--exec=", 7)) {
 232                                 exec = arg + 7;
 233                                 continue;
 234                         }
 235                         if (!strcmp(arg, "--all")) {
 236                                 send_all = 1;
 237                                 continue;
 238                         }
 239                         if (!strcmp(arg, "--force")) {
 240                                 force_update = 1;
 241                                 continue;
 242                         }
 243                         usage(send_pack_usage);
 244                 }
 245                 if (!dest) {
 246                         dest = arg;
 247                         continue;
 248                 }
 249                 heads = argv;
 250                 nr_heads = argc - i;
 251                 break;
 252         }
 253         if (!dest)
 254                 usage(send_pack_usage);
 255         if (heads && send_all)
 256                 usage(send_pack_usage);
 257         pid = git_connect(fd, dest, exec);
 258         if (pid < 0)
 259                 return 1;
 260         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 261         close(fd[0]);
 262         close(fd[1]);
 263         finish_connect(pid);
 264         return ret;
 265 }