send-pack.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3
   4 static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";
   5 static const char *exec = "git-receive-pack";
   6
   7 struct ref {
   8         struct ref *next;
   9         unsigned char old_sha1[20];
  10         unsigned char new_sha1[20];
  11         char name[0];
  12 };
  13
  14 static void exec_pack_objects(void)
  15 {
  16         static char *args[] = {
  17                 "git-pack-objects",
  18                 "--stdout",
  19                 NULL
  20         };
  21         execvp("git-pack-objects", args);
  22         die("git-pack-objects exec failed (%s)", strerror(errno));
  23 }
  24
  25 static void exec_rev_list(struct ref *refs)
  26 {
  27         static char *args[1000];
  28         int i = 0;
  29
  30         args[i++] = "git-rev-list";     /* 0 */
  31         args[i++] = "--objects";        /* 1 */
  32         while (refs) {
  33                 char *buf = malloc(100);
  34                 if (i > 900)
  35                         die("git-rev-list environment overflow");
  36                 args[i++] = buf;
  37                 snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  38                 buf += 50;
  39                 args[i++] = buf;
  40                 snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  41                 refs = refs->next;
  42         }
  43         args[i] = NULL;
  44         execvp("git-rev-list", args);
  45         die("git-rev-list exec failed (%s)", strerror(errno));
  46 }
  47
  48 static void rev_list(int fd, struct ref *refs)
  49 {
  50         int pipe_fd[2];
  51         pid_t pack_objects_pid;
  52
  53         if (pipe(pipe_fd) < 0)
  54                 die("rev-list setup: pipe failed");
  55         pack_objects_pid = fork();
  56         if (!pack_objects_pid) {
  57                 dup2(pipe_fd[0], 0);
  58                 dup2(fd, 1);
  59                 close(pipe_fd[0]);
  60                 close(pipe_fd[1]);
  61                 close(fd);
  62                 exec_pack_objects();
  63                 die("pack-objects setup failed");
  64         }
  65         if (pack_objects_pid < 0)
  66                 die("pack-objects fork failed");
  67         dup2(pipe_fd[1], 1);
  68         close(pipe_fd[0]);
  69         close(pipe_fd[1]);
  70         close(fd);
  71         exec_rev_list(refs);
  72 }
  73
  74 static int pack_objects(int fd, struct ref *refs)
  75 {
  76         pid_t rev_list_pid;
  77
  78         rev_list_pid = fork();
  79         if (!rev_list_pid) {
  80                 rev_list(fd, refs);
  81                 die("rev-list setup failed");
  82         }
  83         if (rev_list_pid < 0)
  84                 die("rev-list fork failed");
  85         /*
  86          * We don't wait for the rev-list pipeline in the parent:
  87          * we end up waiting for the other end instead
  88          */
  89         return 0;
  90 }
  91
  92 static int read_ref(const char *ref, unsigned char *sha1)
  93 {
  94         int fd, ret;
  95         char buffer[60];
  96
  97         fd = open(git_path("%s", ref), O_RDONLY);
  98         if (fd < 0)
  99                 return -1;
 100         ret = -1;
 101         if (read(fd, buffer, sizeof(buffer)) >= 40)
 102                 ret = get_sha1_hex(buffer, sha1);
 103         close(fd);
 104         return ret;
 105 }
 106
 107 static int send_pack(int in, int out, int nr_match, char **match)
 108 {
 109         struct ref *ref_list = NULL, **last_ref = &ref_list;
 110         struct ref *ref;
 111
 112         for (;;) {
 113                 unsigned char old_sha1[20];
 114                 unsigned char new_sha1[20];
 115                 static char buffer[1000];
 116                 char *name;
 117                 int len;
 118
 119                 len = packet_read_line(in, buffer, sizeof(buffer));
 120                 if (!len)
 121                         break;
 122                 if (buffer[len-1] == '\n')
 123                         buffer[--len] = 0;
 124
 125                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
 126                         die("protocol error: expected sha/ref, got '%s'", buffer);
 127                 name = buffer + 41;
 128                 if (nr_match && !path_match(name, nr_match, match))
 129                         continue;
 130                 if (read_ref(name, new_sha1) < 0)
 131                         return error("no such local reference '%s'", name);
 132                 if (!has_sha1_file(old_sha1))
 133                         return error("remote '%s' points to object I don't have", name);
 134                 if (!memcmp(old_sha1, new_sha1, 20)) {
 135                         fprintf(stderr, "'%s' unchanged\n", name);
 136                         continue;
 137                 }
 138                 ref = xmalloc(sizeof(*ref) + len - 40);
 139                 memcpy(ref->old_sha1, old_sha1, 20);
 140                 memcpy(ref->new_sha1, new_sha1, 20);
 141                 memcpy(ref->name, buffer + 41, len - 40);
 142                 ref->next = NULL;
 143                 *last_ref = ref;
 144                 last_ref = &ref->next;
 145         }
 146
 147         for (ref = ref_list; ref; ref = ref->next) {
 148                 char old_hex[60], *new_hex;
 149                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 150                 new_hex = sha1_to_hex(ref->new_sha1);
 151                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 152                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 153         }
 154
 155         packet_flush(out);
 156         if (ref_list)
 157                 pack_objects(out, ref_list);
 158         close(out);
 159         return 0;
 160 }
 161
 162 int main(int argc, char **argv)
 163 {
 164         int i, nr_heads = 0;
 165         char *dest = NULL;
 166         char **heads = NULL;
 167         int fd[2], ret;
 168         pid_t pid;
 169
 170         argv++;
 171         for (i = 1; i < argc; i++) {
 172                 char *arg = *argv++;
 173
 174                 if (*arg == '-') {
 175                         if (!strncmp(arg, "--exec=", 7)) {
 176                                 exec = arg + 7;
 177                                 continue;
 178                         }
 179                         usage(send_pack_usage);
 180                 }
 181                 dest = arg;
 182                 heads = argv;
 183                 nr_heads = argc - i -1;
 184                 break;
 185         }
 186         if (!dest)
 187                 usage(send_pack_usage);
 188         pid = git_connect(fd, dest, exec);
 189         if (pid < 0)
 190                 return 1;
 191         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 192         close(fd[0]);
 193         close(fd[1]);
 194         finish_connect(pid);
 195         return ret;
 196 }