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 [--exec=git-receive-pack] [host:]directory [heads]*";
   8 static const char *exec = "git-receive-pack";
   9 static int send_all = 0;
  10 static int force_update = 0;
  11
  12 static int is_zero_sha1(const unsigned char *sha1)
  13 {
  14         int i;
  15
  16         for (i = 0; i < 20; i++) {
  17                 if (*sha1++)
  18                         return 0;
  19         }
  20         return 1;
  21 }
  22
  23 static void exec_pack_objects(void)
  24 {
  25         static char *args[] = {
  26                 "git-pack-objects",
  27                 "--stdout",
  28                 NULL
  29         };
  30         execvp("git-pack-objects", args);
  31         die("git-pack-objects exec failed (%s)", strerror(errno));
  32 }
  33
  34 static void exec_rev_list(struct ref *refs)
  35 {
  36         static char *args[1000];
  37         int i = 0;
  38
  39         args[i++] = "git-rev-list";     /* 0 */
  40         args[i++] = "--objects";        /* 1 */
  41         while (refs) {
  42                 char *buf = malloc(100);
  43                 if (i > 900)
  44                         die("git-rev-list environment overflow");
  45                 if (!is_zero_sha1(refs->old_sha1)) {
  46                         args[i++] = buf;
  47                         snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  48                         buf += 50;
  49                 }
  50                 if (!is_zero_sha1(refs->new_sha1)) {
  51                         args[i++] = buf;
  52                         snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  53                 }
  54                 refs = refs->next;
  55         }
  56         args[i] = NULL;
  57         execvp("git-rev-list", args);
  58         die("git-rev-list exec failed (%s)", strerror(errno));
  59 }
  60
  61 static void rev_list(int fd, struct ref *refs)
  62 {
  63         int pipe_fd[2];
  64         pid_t pack_objects_pid;
  65
  66         if (pipe(pipe_fd) < 0)
  67                 die("rev-list setup: pipe failed");
  68         pack_objects_pid = fork();
  69         if (!pack_objects_pid) {
  70                 dup2(pipe_fd[0], 0);
  71                 dup2(fd, 1);
  72                 close(pipe_fd[0]);
  73                 close(pipe_fd[1]);
  74                 close(fd);
  75                 exec_pack_objects();
  76                 die("pack-objects setup failed");
  77         }
  78         if (pack_objects_pid < 0)
  79                 die("pack-objects fork failed");
  80         dup2(pipe_fd[1], 1);
  81         close(pipe_fd[0]);
  82         close(pipe_fd[1]);
  83         close(fd);
  84         exec_rev_list(refs);
  85 }
  86
  87 static int pack_objects(int fd, struct ref *refs)
  88 {
  89         pid_t rev_list_pid;
  90
  91         rev_list_pid = fork();
  92         if (!rev_list_pid) {
  93                 rev_list(fd, refs);
  94                 die("rev-list setup failed");
  95         }
  96         if (rev_list_pid < 0)
  97                 die("rev-list fork failed");
  98         /*
  99          * We don't wait for the rev-list pipeline in the parent:
 100          * we end up waiting for the other end instead
 101          */
 102         return 0;
 103 }
 104
 105 static int read_ref(const char *ref, unsigned char *sha1)
 106 {
 107         int fd, ret;
 108         char buffer[60];
 109
 110         fd = open(git_path("%s", ref), O_RDONLY);
 111         if (fd < 0)
 112                 return -1;
 113         ret = -1;
 114         if (read(fd, buffer, sizeof(buffer)) >= 40)
 115                 ret = get_sha1_hex(buffer, sha1);
 116         close(fd);
 117         return ret;
 118 }
 119
 120 static int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 121 {
 122         struct commit *new, *old;
 123         struct commit_list *list;
 124
 125         if (force_update)
 126                 return 1;
 127         old = lookup_commit_reference(old_sha1);
 128         if (!old)
 129                 return 0;
 130         new = lookup_commit_reference(new_sha1);
 131         if (!new)
 132                 return 0;
 133         if (parse_commit(new) < 0)
 134                 return 0;
 135         list = NULL;
 136         commit_list_insert(new, &list);
 137         while ((new = pop_most_recent_commit(&list, 1)) != NULL) {
 138                 if (new == old)
 139                         return 1;
 140         }
 141         return 0;
 142 }
 143
 144 static int local_ref_nr_match;
 145 static char **local_ref_match;
 146 static struct ref *local_ref_list;
 147 static struct ref **local_last_ref;
 148
 149 static int try_to_match(const char *refname, const unsigned char *sha1)
 150 {
 151         struct ref *ref;
 152         int len;
 153
 154         if (!path_match(refname, local_ref_nr_match, local_ref_match)) {
 155                 if (!send_all)
 156                         return 0;
 157
 158                 /* If we have it listed already, skip it */
 159                 for (ref = local_ref_list ; ref ; ref = ref->next) {
 160                         if (!strcmp(ref->name, refname))
 161                                 return 0;
 162                 }
 163         }
 164
 165         len = strlen(refname)+1;
 166         ref = xmalloc(sizeof(*ref) + len);
 167         memset(ref->old_sha1, 0, 20);
 168         memcpy(ref->new_sha1, sha1, 20);
 169         memcpy(ref->name, refname, len);
 170         ref->next = NULL;
 171         *local_last_ref = ref;
 172         local_last_ref = &ref->next;
 173         return 0;
 174 }
 175
 176 static int send_pack(int in, int out, int nr_match, char **match)
 177 {
 178         struct ref *ref_list, **last_ref;
 179         struct ref *ref;
 180         int new_refs;
 181
 182         /* First we get all heads, whether matching or not.. */
 183         last_ref = get_remote_heads(in, &ref_list, 0, NULL);
 184
 185         /*
 186          * Go through the refs, see if we want to update
 187          * any of them..
 188          */
 189         for (ref = ref_list; ref; ref = ref->next) {
 190                 unsigned char new_sha1[20];
 191                 char *name = ref->name;
 192
 193                 if (nr_match && !path_match(name, nr_match, match))
 194                         continue;
 195
 196                 if (read_ref(name, new_sha1) < 0)
 197                         continue;
 198
 199                 if (!memcmp(ref->old_sha1, new_sha1, 20)) {
 200                         fprintf(stderr, "'%s' unchanged\n", name);
 201                         continue;
 202                 }
 203
 204                 if (!ref_newer(new_sha1, ref->old_sha1)) {
 205                         error("remote '%s' isn't a strict parent of local", name);
 206                         continue;
 207                 }
 208
 209                 /* Ok, mark it for update */
 210                 memcpy(ref->new_sha1, new_sha1, 20);
 211         }
 212
 213         /*
 214          * See if we have any refs that the other end didn't have
 215          */
 216         if (nr_match) {
 217                 local_ref_nr_match = nr_match;
 218                 local_ref_match = match;
 219                 local_ref_list = ref_list;
 220                 local_last_ref = last_ref;
 221                 for_each_ref(try_to_match);
 222         }
 223
 224         /*
 225          * Finally, tell the other end!
 226          */
 227         new_refs = 0;
 228         for (ref = ref_list; ref; ref = ref->next) {
 229                 char old_hex[60], *new_hex;
 230                 if (is_zero_sha1(ref->new_sha1))
 231                         continue;
 232                 new_refs++;
 233                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 234                 new_hex = sha1_to_hex(ref->new_sha1);
 235                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 236                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 237         }
 238
 239         packet_flush(out);
 240         if (new_refs)
 241                 pack_objects(out, ref_list);
 242         close(out);
 243         return 0;
 244 }
 245
 246 int main(int argc, char **argv)
 247 {
 248         int i, nr_heads = 0;
 249         char *dest = NULL;
 250         char **heads = NULL;
 251         int fd[2], ret;
 252         pid_t pid;
 253
 254         argv++;
 255         for (i = 1; i < argc; i++, argv++) {
 256                 char *arg = *argv;
 257
 258                 if (*arg == '-') {
 259                         if (!strncmp(arg, "--exec=", 7)) {
 260                                 exec = arg + 7;
 261                                 continue;
 262                         }
 263                         if (!strcmp(arg, "--all")) {
 264                                 send_all = 1;
 265                                 continue;
 266                         }
 267                         if (!strcmp(arg, "--force")) {
 268                                 force_update = 1;
 269                                 continue;
 270                         }
 271                         usage(send_pack_usage);
 272                 }
 273                 if (!dest) {
 274                         dest = arg;
 275                         continue;
 276                 }
 277                 heads = argv;
 278                 nr_heads = argc - i;
 279                 break;
 280         }
 281         if (!dest)
 282                 usage(send_pack_usage);
 283         pid = git_connect(fd, dest, exec);
 284         if (pid < 0)
 285                 return 1;
 286         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 287         close(fd[0]);
 288         close(fd[1]);
 289         finish_connect(pid);
 290         return ret;
 291 }