send-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4
   5 static const char send_pack_usage[] =
   6 "git-send-pack [--exec=git-receive-pack] [host:]directory [heads]*";
   7 static const char *exec = "git-receive-pack";
   8 static int send_all = 0;
   9
  10 static int is_zero_sha1(const unsigned char *sha1)
  11 {
  12         int i;
  13
  14         for (i = 0; i < 20; i++) {
  15                 if (*sha1++)
  16                         return 0;
  17         }
  18         return 1;
  19 }
  20
  21 static void exec_pack_objects(void)
  22 {
  23         static char *args[] = {
  24                 "git-pack-objects",
  25                 "--stdout",
  26                 NULL
  27         };
  28         execvp("git-pack-objects", args);
  29         die("git-pack-objects exec failed (%s)", strerror(errno));
  30 }
  31
  32 static void exec_rev_list(struct ref *refs)
  33 {
  34         static char *args[1000];
  35         int i = 0;
  36
  37         args[i++] = "git-rev-list";     /* 0 */
  38         args[i++] = "--objects";        /* 1 */
  39         while (refs) {
  40                 char *buf = malloc(100);
  41                 if (i > 900)
  42                         die("git-rev-list environment overflow");
  43                 if (!is_zero_sha1(refs->old_sha1)) {
  44                         args[i++] = buf;
  45                         snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  46                         buf += 50;
  47                 }
  48                 if (!is_zero_sha1(refs->new_sha1)) {
  49                         args[i++] = buf;
  50                         snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  51                 }
  52                 refs = refs->next;
  53         }
  54         args[i] = NULL;
  55         execvp("git-rev-list", args);
  56         die("git-rev-list exec failed (%s)", strerror(errno));
  57 }
  58
  59 static void rev_list(int fd, struct ref *refs)
  60 {
  61         int pipe_fd[2];
  62         pid_t pack_objects_pid;
  63
  64         if (pipe(pipe_fd) < 0)
  65                 die("rev-list setup: pipe failed");
  66         pack_objects_pid = fork();
  67         if (!pack_objects_pid) {
  68                 dup2(pipe_fd[0], 0);
  69                 dup2(fd, 1);
  70                 close(pipe_fd[0]);
  71                 close(pipe_fd[1]);
  72                 close(fd);
  73                 exec_pack_objects();
  74                 die("pack-objects setup failed");
  75         }
  76         if (pack_objects_pid < 0)
  77                 die("pack-objects fork failed");
  78         dup2(pipe_fd[1], 1);
  79         close(pipe_fd[0]);
  80         close(pipe_fd[1]);
  81         close(fd);
  82         exec_rev_list(refs);
  83 }
  84
  85 static int pack_objects(int fd, struct ref *refs)
  86 {
  87         pid_t rev_list_pid;
  88
  89         rev_list_pid = fork();
  90         if (!rev_list_pid) {
  91                 rev_list(fd, refs);
  92                 die("rev-list setup failed");
  93         }
  94         if (rev_list_pid < 0)
  95                 die("rev-list fork failed");
  96         /*
  97          * We don't wait for the rev-list pipeline in the parent:
  98          * we end up waiting for the other end instead
  99          */
 100         return 0;
 101 }
 102
 103 static int read_ref(const char *ref, unsigned char *sha1)
 104 {
 105         int fd, ret;
 106         char buffer[60];
 107
 108         fd = open(git_path("%s", ref), O_RDONLY);
 109         if (fd < 0)
 110                 return -1;
 111         ret = -1;
 112         if (read(fd, buffer, sizeof(buffer)) >= 40)
 113                 ret = get_sha1_hex(buffer, sha1);
 114         close(fd);
 115         return ret;
 116 }
 117
 118 static int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 119 {
 120         if (!has_sha1_file(old_sha1))
 121                 return 0;
 122         /*
 123          * FIXME! It is not correct to say that the new one is newer
 124          * just because we don't have the old one!
 125          *
 126          * We should really see if we can reach the old_sha1 commit
 127          * from the new_sha1 one.
 128          */
 129         return 1;
 130 }
 131
 132 static int local_ref_nr_match;
 133 static char **local_ref_match;
 134 static struct ref *local_ref_list;
 135 static struct ref **local_last_ref;
 136
 137 static int try_to_match(const char *refname, const unsigned char *sha1)
 138 {
 139         struct ref *ref;
 140         int len;
 141
 142         if (!path_match(refname, local_ref_nr_match, local_ref_match)) {
 143                 if (!send_all)
 144                         return 0;
 145
 146                 /* If we have it listed already, skip it */
 147                 for (ref = local_ref_list ; ref ; ref = ref->next) {
 148                         if (!strcmp(ref->name, refname))
 149                                 return 0;
 150                 }
 151         }
 152
 153         len = strlen(refname)+1;
 154         ref = xmalloc(sizeof(*ref) + len);
 155         memset(ref->old_sha1, 0, 20);
 156         memcpy(ref->new_sha1, sha1, 20);
 157         memcpy(ref->name, refname, len);
 158         ref->next = NULL;
 159         *local_last_ref = ref;
 160         local_last_ref = &ref->next;
 161         return 0;
 162 }
 163
 164 static int send_pack(int in, int out, int nr_match, char **match)
 165 {
 166         struct ref *ref_list, **last_ref;
 167         struct ref *ref;
 168         int new_refs;
 169
 170         /* First we get all heads, whether matching or not.. */
 171         last_ref = get_remote_heads(in, &ref_list, 0, NULL);
 172
 173         /*
 174          * Go through the refs, see if we want to update
 175          * any of them..
 176          */
 177         for (ref = ref_list; ref; ref = ref->next) {
 178                 unsigned char new_sha1[20];
 179                 char *name = ref->name;
 180
 181                 if (nr_match && !path_match(name, nr_match, match))
 182                         continue;
 183
 184                 if (read_ref(name, new_sha1) < 0)
 185                         continue;
 186
 187                 if (!memcmp(ref->old_sha1, new_sha1, 20)) {
 188                         fprintf(stderr, "'%s' unchanged\n", name);
 189                         continue;
 190                 }
 191
 192                 if (!ref_newer(new_sha1, ref->old_sha1)) {
 193                         error("remote '%s' points to object I don't have", name);
 194                         continue;
 195                 }
 196
 197                 /* Ok, mark it for update */
 198                 memcpy(ref->new_sha1, new_sha1, 20);
 199         }
 200
 201         /*
 202          * See if we have any refs that the other end didn't have
 203          */
 204         if (nr_match) {
 205                 local_ref_nr_match = nr_match;
 206                 local_ref_match = match;
 207                 local_ref_list = ref_list;
 208                 local_last_ref = last_ref;
 209                 for_each_ref(try_to_match);
 210         }
 211
 212         /*
 213          * Finally, tell the other end!
 214          */
 215         new_refs = 0;
 216         for (ref = ref_list; ref; ref = ref->next) {
 217                 char old_hex[60], *new_hex;
 218                 if (is_zero_sha1(ref->new_sha1))
 219                         continue;
 220                 new_refs++;
 221                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 222                 new_hex = sha1_to_hex(ref->new_sha1);
 223                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 224                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 225         }
 226
 227         packet_flush(out);
 228         if (new_refs)
 229                 pack_objects(out, ref_list);
 230         close(out);
 231         return 0;
 232 }
 233
 234 int main(int argc, char **argv)
 235 {
 236         int i, nr_heads = 0;
 237         char *dest = NULL;
 238         char **heads = NULL;
 239         int fd[2], ret;
 240         pid_t pid;
 241
 242         argv++;
 243         for (i = 1; i < argc; i++, argv++) {
 244                 char *arg = *argv;
 245
 246                 if (*arg == '-') {
 247                         if (!strncmp(arg, "--exec=", 7)) {
 248                                 exec = arg + 7;
 249                                 continue;
 250                         }
 251                         if (!strcmp(arg, "--all")) {
 252                                 send_all = 1;
 253                                 continue;
 254                         }
 255                         usage(send_pack_usage);
 256                 }
 257                 if (!dest) {
 258                         dest = arg;
 259                         continue;
 260                 }
 261                 heads = argv;
 262                 nr_heads = argc - i;
 263                 break;
 264         }
 265         if (!dest)
 266                 usage(send_pack_usage);
 267         pid = git_connect(fd, dest, exec);
 268         if (pid < 0)
 269                 return 1;
 270         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 271         close(fd[0]);
 272         close(fd[1]);
 273         finish_connect(pid);
 274         return ret;
 275 }