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 read_ref(const char *ref, unsigned char *sha1)
 108 {
 109         int fd, ret;
 110         char buffer[60];
 111
 112         fd = open(git_path("%s", ref), O_RDONLY);
 113         if (fd < 0)
 114                 return -1;
 115         ret = -1;
 116         if (read(fd, buffer, sizeof(buffer)) >= 40)
 117                 ret = get_sha1_hex(buffer, sha1);
 118         close(fd);
 119         return ret;
 120 }
 121
 122 static int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 123 {
 124         struct commit *new, *old;
 125         struct commit_list *list;
 126
 127         if (force_update)
 128                 return 1;
 129         old = lookup_commit_reference(old_sha1);
 130         if (!old)
 131                 return 0;
 132         new = lookup_commit_reference(new_sha1);
 133         if (!new)
 134                 return 0;
 135         if (parse_commit(new) < 0)
 136                 return 0;
 137         list = NULL;
 138         commit_list_insert(new, &list);
 139         while (list) {
 140                 new = pop_most_recent_commit(&list, 1);
 141                 if (new == old)
 142                         return 1;
 143         }
 144         return 0;
 145 }
 146
 147 static int local_ref_nr_match;
 148 static char **local_ref_match;
 149 static struct ref *local_ref_list;
 150 static struct ref **local_last_ref;
 151
 152 static int try_to_match(const char *refname, const unsigned char *sha1)
 153 {
 154         struct ref *ref;
 155         int len;
 156
 157         if (!path_match(refname, local_ref_nr_match, local_ref_match)) {
 158                 if (!send_all)
 159                         return 0;
 160
 161                 /* If we have it listed already, skip it */
 162                 for (ref = local_ref_list ; ref ; ref = ref->next) {
 163                         if (!strcmp(ref->name, refname))
 164                                 return 0;
 165                 }
 166         }
 167
 168         len = strlen(refname)+1;
 169         ref = xmalloc(sizeof(*ref) + len);
 170         memset(ref->old_sha1, 0, 20);
 171         memcpy(ref->new_sha1, sha1, 20);
 172         memcpy(ref->name, refname, len);
 173         ref->next = NULL;
 174         *local_last_ref = ref;
 175         local_last_ref = &ref->next;
 176         return 0;
 177 }
 178
 179 static int send_pack(int in, int out, int nr_match, char **match)
 180 {
 181         struct ref *ref_list, **last_ref;
 182         struct ref *ref;
 183         int new_refs;
 184
 185         /* First we get all heads, whether matching or not.. */
 186         last_ref = get_remote_heads(in, &ref_list, 0, NULL);
 187
 188         /*
 189          * Go through the refs, see if we want to update
 190          * any of them..
 191          */
 192         for (ref = ref_list; ref; ref = ref->next) {
 193                 unsigned char new_sha1[20];
 194                 char *name = ref->name;
 195
 196                 if (nr_match && !path_match(name, nr_match, match))
 197                         continue;
 198
 199                 if (read_ref(name, new_sha1) < 0)
 200                         continue;
 201
 202                 if (!memcmp(ref->old_sha1, new_sha1, 20)) {
 203                         fprintf(stderr, "'%s' unchanged\n", name);
 204                         continue;
 205                 }
 206
 207                 if (!has_sha1_file(ref->old_sha1)) {
 208                         error("remote '%s' object %s does not exist on local",
 209                               name, sha1_to_hex(ref->old_sha1));
 210                         continue;
 211                 }
 212
 213                 if (!ref_newer(new_sha1, ref->old_sha1)) {
 214                         error("remote '%s' isn't a strict parent of local", name);
 215                         continue;
 216                 }
 217
 218                 /* Ok, mark it for update */
 219                 memcpy(ref->new_sha1, new_sha1, 20);
 220         }
 221
 222         /*
 223          * See if we have any refs that the other end didn't have
 224          */
 225         if (nr_match || send_all) {
 226                 local_ref_nr_match = nr_match;
 227                 local_ref_match = match;
 228                 local_ref_list = ref_list;
 229                 local_last_ref = last_ref;
 230                 for_each_ref(try_to_match);
 231         }
 232
 233         /*
 234          * Finally, tell the other end!
 235          */
 236         new_refs = 0;
 237         for (ref = ref_list; ref; ref = ref->next) {
 238                 char old_hex[60], *new_hex;
 239                 if (is_zero_sha1(ref->new_sha1))
 240                         continue;
 241                 new_refs++;
 242                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 243                 new_hex = sha1_to_hex(ref->new_sha1);
 244                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 245                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 246         }
 247
 248         packet_flush(out);
 249         if (new_refs)
 250                 pack_objects(out, ref_list);
 251         close(out);
 252         return 0;
 253 }
 254
 255 int main(int argc, char **argv)
 256 {
 257         int i, nr_heads = 0;
 258         char *dest = NULL;
 259         char **heads = NULL;
 260         int fd[2], ret;
 261         pid_t pid;
 262
 263         argv++;
 264         for (i = 1; i < argc; i++, argv++) {
 265                 char *arg = *argv;
 266
 267                 if (*arg == '-') {
 268                         if (!strncmp(arg, "--exec=", 7)) {
 269                                 exec = arg + 7;
 270                                 continue;
 271                         }
 272                         if (!strcmp(arg, "--all")) {
 273                                 send_all = 1;
 274                                 continue;
 275                         }
 276                         if (!strcmp(arg, "--force")) {
 277                                 force_update = 1;
 278                                 continue;
 279                         }
 280                         usage(send_pack_usage);
 281                 }
 282                 if (!dest) {
 283                         dest = arg;
 284                         continue;
 285                 }
 286                 heads = argv;
 287                 nr_heads = argc - i;
 288                 break;
 289         }
 290         if (!dest)
 291                 usage(send_pack_usage);
 292         if (heads && send_all)
 293                 usage(send_pack_usage);
 294         pid = git_connect(fd, dest, exec);
 295         if (pid < 0)
 296                 return 1;
 297         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 298         close(fd[0]);
 299         close(fd[1]);
 300         finish_connect(pid);
 301         return ret;
 302 }