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                         args[i++] = buf;
  48                         snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  49                         buf += 50;
  50                 }
  51                 if (!is_zero_sha1(refs->new_sha1)) {
  52                         args[i++] = buf;
  53                         snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  54                 }
  55                 refs = refs->next;
  56         }
  57         args[i] = NULL;
  58         execvp("git-rev-list", args);
  59         die("git-rev-list exec failed (%s)", strerror(errno));
  60 }
  61
  62 static void rev_list(int fd, struct ref *refs)
  63 {
  64         int pipe_fd[2];
  65         pid_t pack_objects_pid;
  66
  67         if (pipe(pipe_fd) < 0)
  68                 die("rev-list setup: pipe failed");
  69         pack_objects_pid = fork();
  70         if (!pack_objects_pid) {
  71                 dup2(pipe_fd[0], 0);
  72                 dup2(fd, 1);
  73                 close(pipe_fd[0]);
  74                 close(pipe_fd[1]);
  75                 close(fd);
  76                 exec_pack_objects();
  77                 die("pack-objects setup failed");
  78         }
  79         if (pack_objects_pid < 0)
  80                 die("pack-objects fork failed");
  81         dup2(pipe_fd[1], 1);
  82         close(pipe_fd[0]);
  83         close(pipe_fd[1]);
  84         close(fd);
  85         exec_rev_list(refs);
  86 }
  87
  88 static int pack_objects(int fd, struct ref *refs)
  89 {
  90         pid_t rev_list_pid;
  91
  92         rev_list_pid = fork();
  93         if (!rev_list_pid) {
  94                 rev_list(fd, refs);
  95                 die("rev-list setup failed");
  96         }
  97         if (rev_list_pid < 0)
  98                 die("rev-list fork failed");
  99         /*
 100          * We don't wait for the rev-list pipeline in the parent:
 101          * we end up waiting for the other end instead
 102          */
 103         return 0;
 104 }
 105
 106 static int read_ref(const char *ref, unsigned char *sha1)
 107 {
 108         int fd, ret;
 109         char buffer[60];
 110
 111         fd = open(git_path("%s", ref), O_RDONLY);
 112         if (fd < 0)
 113                 return -1;
 114         ret = -1;
 115         if (read(fd, buffer, sizeof(buffer)) >= 40)
 116                 ret = get_sha1_hex(buffer, sha1);
 117         close(fd);
 118         return ret;
 119 }
 120
 121 static int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 122 {
 123         struct commit *new, *old;
 124         struct commit_list *list;
 125
 126         if (force_update)
 127                 return 1;
 128         old = lookup_commit_reference(old_sha1);
 129         if (!old)
 130                 return 0;
 131         new = lookup_commit_reference(new_sha1);
 132         if (!new)
 133                 return 0;
 134         if (parse_commit(new) < 0)
 135                 return 0;
 136         list = NULL;
 137         commit_list_insert(new, &list);
 138         while (list) {
 139                 new = pop_most_recent_commit(&list, 1);
 140                 if (new == old)
 141                         return 1;
 142         }
 143         return 0;
 144 }
 145
 146 static int local_ref_nr_match;
 147 static char **local_ref_match;
 148 static struct ref *local_ref_list;
 149 static struct ref **local_last_ref;
 150
 151 static int try_to_match(const char *refname, const unsigned char *sha1)
 152 {
 153         struct ref *ref;
 154         int len;
 155
 156         if (!path_match(refname, local_ref_nr_match, local_ref_match)) {
 157                 if (!send_all)
 158                         return 0;
 159
 160                 /* If we have it listed already, skip it */
 161                 for (ref = local_ref_list ; ref ; ref = ref->next) {
 162                         if (!strcmp(ref->name, refname))
 163                                 return 0;
 164                 }
 165         }
 166
 167         len = strlen(refname)+1;
 168         ref = xmalloc(sizeof(*ref) + len);
 169         memset(ref->old_sha1, 0, 20);
 170         memcpy(ref->new_sha1, sha1, 20);
 171         memcpy(ref->name, refname, len);
 172         ref->next = NULL;
 173         *local_last_ref = ref;
 174         local_last_ref = &ref->next;
 175         return 0;
 176 }
 177
 178 static int send_pack(int in, int out, int nr_match, char **match)
 179 {
 180         struct ref *ref_list, **last_ref;
 181         struct ref *ref;
 182         int new_refs;
 183
 184         /* First we get all heads, whether matching or not.. */
 185         last_ref = get_remote_heads(in, &ref_list, 0, NULL);
 186
 187         /*
 188          * Go through the refs, see if we want to update
 189          * any of them..
 190          */
 191         for (ref = ref_list; ref; ref = ref->next) {
 192                 unsigned char new_sha1[20];
 193                 char *name = ref->name;
 194
 195                 if (nr_match && !path_match(name, nr_match, match))
 196                         continue;
 197
 198                 if (read_ref(name, new_sha1) < 0)
 199                         continue;
 200
 201                 if (!memcmp(ref->old_sha1, new_sha1, 20)) {
 202                         fprintf(stderr, "'%s' unchanged\n", name);
 203                         continue;
 204                 }
 205
 206                 if (!ref_newer(new_sha1, ref->old_sha1)) {
 207                         error("remote '%s' isn't a strict parent of local", name);
 208                         continue;
 209                 }
 210
 211                 /* Ok, mark it for update */
 212                 memcpy(ref->new_sha1, new_sha1, 20);
 213         }
 214
 215         /*
 216          * See if we have any refs that the other end didn't have
 217          */
 218         if (nr_match || send_all) {
 219                 local_ref_nr_match = nr_match;
 220                 local_ref_match = match;
 221                 local_ref_list = ref_list;
 222                 local_last_ref = last_ref;
 223                 for_each_ref(try_to_match);
 224         }
 225
 226         /*
 227          * Finally, tell the other end!
 228          */
 229         new_refs = 0;
 230         for (ref = ref_list; ref; ref = ref->next) {
 231                 char old_hex[60], *new_hex;
 232                 if (is_zero_sha1(ref->new_sha1))
 233                         continue;
 234                 new_refs++;
 235                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 236                 new_hex = sha1_to_hex(ref->new_sha1);
 237                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 238                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 239         }
 240
 241         packet_flush(out);
 242         if (new_refs)
 243                 pack_objects(out, ref_list);
 244         close(out);
 245         return 0;
 246 }
 247
 248 int main(int argc, char **argv)
 249 {
 250         int i, nr_heads = 0;
 251         char *dest = NULL;
 252         char **heads = NULL;
 253         int fd[2], ret;
 254         pid_t pid;
 255
 256         argv++;
 257         for (i = 1; i < argc; i++, argv++) {
 258                 char *arg = *argv;
 259
 260                 if (*arg == '-') {
 261                         if (!strncmp(arg, "--exec=", 7)) {
 262                                 exec = arg + 7;
 263                                 continue;
 264                         }
 265                         if (!strcmp(arg, "--all")) {
 266                                 send_all = 1;
 267                                 continue;
 268                         }
 269                         if (!strcmp(arg, "--force")) {
 270                                 force_update = 1;
 271                                 continue;
 272                         }
 273                         usage(send_pack_usage);
 274                 }
 275                 if (!dest) {
 276                         dest = arg;
 277                         continue;
 278                 }
 279                 heads = argv;
 280                 nr_heads = argc - i;
 281                 break;
 282         }
 283         if (!dest)
 284                 usage(send_pack_usage);
 285         if (heads && send_all)
 286                 usage(send_pack_usage);
 287         pid = git_connect(fd, dest, exec);
 288         if (pid < 0)
 289                 return 1;
 290         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 291         close(fd[0]);
 292         close(fd[1]);
 293         finish_connect(pid);
 294         return ret;
 295 }