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 struct ref {
  11         struct ref *next;
  12         unsigned char old_sha1[20];
  13         unsigned char new_sha1[20];
  14         char name[0];
  15 };
  16
  17 static int is_zero_sha1(const unsigned char *sha1)
  18 {
  19         int i;
  20
  21         for (i = 0; i < 20; i++) {
  22                 if (*sha1++)
  23                         return 0;
  24         }
  25         return 1;
  26 }
  27
  28 static void exec_pack_objects(void)
  29 {
  30         static char *args[] = {
  31                 "git-pack-objects",
  32                 "--stdout",
  33                 NULL
  34         };
  35         execvp("git-pack-objects", args);
  36         die("git-pack-objects exec failed (%s)", strerror(errno));
  37 }
  38
  39 static void exec_rev_list(struct ref *refs)
  40 {
  41         static char *args[1000];
  42         int i = 0;
  43
  44         args[i++] = "git-rev-list";     /* 0 */
  45         args[i++] = "--objects";        /* 1 */
  46         while (refs) {
  47                 char *buf = malloc(100);
  48                 if (i > 900)
  49                         die("git-rev-list environment overflow");
  50                 if (!is_zero_sha1(refs->old_sha1)) {
  51                         args[i++] = buf;
  52                         snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  53                         buf += 50;
  54                 }
  55                 if (!is_zero_sha1(refs->new_sha1)) {
  56                         args[i++] = buf;
  57                         snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  58                 }
  59                 refs = refs->next;
  60         }
  61         args[i] = NULL;
  62         execvp("git-rev-list", args);
  63         die("git-rev-list exec failed (%s)", strerror(errno));
  64 }
  65
  66 static void rev_list(int fd, struct ref *refs)
  67 {
  68         int pipe_fd[2];
  69         pid_t pack_objects_pid;
  70
  71         if (pipe(pipe_fd) < 0)
  72                 die("rev-list setup: pipe failed");
  73         pack_objects_pid = fork();
  74         if (!pack_objects_pid) {
  75                 dup2(pipe_fd[0], 0);
  76                 dup2(fd, 1);
  77                 close(pipe_fd[0]);
  78                 close(pipe_fd[1]);
  79                 close(fd);
  80                 exec_pack_objects();
  81                 die("pack-objects setup failed");
  82         }
  83         if (pack_objects_pid < 0)
  84                 die("pack-objects fork failed");
  85         dup2(pipe_fd[1], 1);
  86         close(pipe_fd[0]);
  87         close(pipe_fd[1]);
  88         close(fd);
  89         exec_rev_list(refs);
  90 }
  91
  92 static int pack_objects(int fd, struct ref *refs)
  93 {
  94         pid_t rev_list_pid;
  95
  96         rev_list_pid = fork();
  97         if (!rev_list_pid) {
  98                 rev_list(fd, refs);
  99                 die("rev-list setup failed");
 100         }
 101         if (rev_list_pid < 0)
 102                 die("rev-list fork failed");
 103         /*
 104          * We don't wait for the rev-list pipeline in the parent:
 105          * we end up waiting for the other end instead
 106          */
 107         return 0;
 108 }
 109
 110 static int read_ref(const char *ref, unsigned char *sha1)
 111 {
 112         int fd, ret;
 113         char buffer[60];
 114
 115         fd = open(git_path("%s", ref), O_RDONLY);
 116         if (fd < 0)
 117                 return -1;
 118         ret = -1;
 119         if (read(fd, buffer, sizeof(buffer)) >= 40)
 120                 ret = get_sha1_hex(buffer, sha1);
 121         close(fd);
 122         return ret;
 123 }
 124
 125 static int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 126 {
 127         if (!has_sha1_file(old_sha1))
 128                 return 0;
 129         /*
 130          * FIXME! It is not correct to say that the new one is newer
 131          * just because we don't have the old one!
 132          *
 133          * We should really see if we can reach the old_sha1 commit
 134          * from the new_sha1 one.
 135          */
 136         return 1;
 137 }
 138
 139 static int local_ref_nr_match;
 140 static char **local_ref_match;
 141 static struct ref *local_ref_list;
 142 static struct ref **local_last_ref;
 143
 144 static int try_to_match(const char *refname, const unsigned char *sha1)
 145 {
 146         struct ref *ref;
 147         int len;
 148
 149         if (!path_match(refname, local_ref_nr_match, local_ref_match)) {
 150                 if (!send_all)
 151                         return 0;
 152
 153                 /* If we have it listed already, skip it */
 154                 for (ref = local_ref_list ; ref ; ref = ref->next) {
 155                         if (!strcmp(ref->name, refname))
 156                                 return 0;
 157                 }
 158         }
 159
 160         len = strlen(refname)+1;
 161         ref = xmalloc(sizeof(*ref) + len);
 162         memset(ref->old_sha1, 0, 20);
 163         memcpy(ref->new_sha1, sha1, 20);
 164         memcpy(ref->name, refname, len);
 165         ref->next = NULL;
 166         *local_last_ref = ref;
 167         local_last_ref = &ref->next;
 168         return 0;
 169 }
 170
 171 static int send_pack(int in, int out, int nr_match, char **match)
 172 {
 173         struct ref *ref_list = NULL, **last_ref = &ref_list;
 174         struct ref *ref;
 175         int new_refs;
 176
 177         /*
 178          * Read all the refs from the other end
 179          */
 180         for (;;) {
 181                 unsigned char old_sha1[20];
 182                 static char buffer[1000];
 183                 char *name;
 184                 int len;
 185
 186                 len = packet_read_line(in, buffer, sizeof(buffer));
 187                 if (!len)
 188                         break;
 189                 if (buffer[len-1] == '\n')
 190                         buffer[--len] = 0;
 191
 192                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
 193                         die("protocol error: expected sha/ref, got '%s'", buffer);
 194                 name = buffer + 41;
 195                 ref = xmalloc(sizeof(*ref) + len - 40);
 196                 memcpy(ref->old_sha1, old_sha1, 20);
 197                 memset(ref->new_sha1, 0, 20);
 198                 memcpy(ref->name, buffer + 41, len - 40);
 199                 ref->next = NULL;
 200                 *last_ref = ref;
 201                 last_ref = &ref->next;
 202         }
 203
 204         /*
 205          * Go through the refs, see if we want to update
 206          * any of them..
 207          */
 208         for (ref = ref_list; ref; ref = ref->next) {
 209                 unsigned char new_sha1[20];
 210                 char *name = ref->name;
 211
 212                 if (nr_match && !path_match(name, nr_match, match))
 213                         continue;
 214
 215                 if (read_ref(name, new_sha1) < 0)
 216                         continue;
 217
 218                 if (!memcmp(ref->old_sha1, new_sha1, 20)) {
 219                         fprintf(stderr, "'%s' unchanged\n", name);
 220                         continue;
 221                 }
 222
 223                 if (!ref_newer(new_sha1, ref->old_sha1)) {
 224                         error("remote '%s' points to object I don't have", name);
 225                         continue;
 226                 }
 227
 228                 /* Ok, mark it for update */
 229                 memcpy(ref->new_sha1, new_sha1, 20);
 230         }
 231
 232         /*
 233          * See if we have any refs that the other end didn't have
 234          */
 235         if (nr_match) {
 236                 local_ref_nr_match = nr_match;
 237                 local_ref_match = match;
 238                 local_ref_list = ref_list;
 239                 local_last_ref = last_ref;
 240                 for_each_ref(try_to_match);
 241         }
 242
 243         /*
 244          * Finally, tell the other end!
 245          */
 246         new_refs = 0;
 247         for (ref = ref_list; ref; ref = ref->next) {
 248                 char old_hex[60], *new_hex;
 249                 if (is_zero_sha1(ref->new_sha1))
 250                         continue;
 251                 new_refs++;
 252                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 253                 new_hex = sha1_to_hex(ref->new_sha1);
 254                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 255                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 256         }
 257
 258         packet_flush(out);
 259         if (new_refs)
 260                 pack_objects(out, ref_list);
 261         close(out);
 262         return 0;
 263 }
 264
 265 int main(int argc, char **argv)
 266 {
 267         int i, nr_heads = 0;
 268         char *dest = NULL;
 269         char **heads = NULL;
 270         int fd[2], ret;
 271         pid_t pid;
 272
 273         argv++;
 274         for (i = 1; i < argc; i++, argv++) {
 275                 char *arg = *argv;
 276
 277                 if (*arg == '-') {
 278                         if (!strncmp(arg, "--exec=", 7)) {
 279                                 exec = arg + 7;
 280                                 continue;
 281                         }
 282                         if (!strcmp(arg, "--all")) {
 283                                 send_all = 1;
 284                                 continue;
 285                         }
 286                         usage(send_pack_usage);
 287                 }
 288                 if (!dest) {
 289                         dest = arg;
 290                         continue;
 291                 }
 292                 heads = argv;
 293                 nr_heads = argc - i;
 294                 break;
 295         }
 296         if (!dest)
 297                 usage(send_pack_usage);
 298         pid = git_connect(fd, dest, exec);
 299         if (pid < 0)
 300                 return 1;
 301         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 302         close(fd[0]);
 303         close(fd[1]);
 304         finish_connect(pid);
 305         return ret;
 306 }