ssh-fetch.c

   1 #ifndef COUNTERPART_ENV_NAME
   2 #define COUNTERPART_ENV_NAME "GIT_SSH_UPLOAD"
   3 #endif
   4 #ifndef COUNTERPART_PROGRAM_NAME
   5 #define COUNTERPART_PROGRAM_NAME "git-ssh-upload"
   6 #endif
   7 #ifndef MY_PROGRAM_NAME
   8 #define MY_PROGRAM_NAME "git-ssh-fetch"
   9 #endif
  10
  11 #include "cache.h"
  12 #include "commit.h"
  13 #include "rsh.h"
  14 #include "fetch.h"
  15 #include "refs.h"
  16
  17 static int fd_in;
  18 static int fd_out;
  19
  20 static unsigned char remote_version;
  21 static unsigned char local_version = 1;
  22
  23 static int prefetches;
  24
  25 static struct object_list *in_transit;
  26 static struct object_list **end_of_transit = &in_transit;
  27
  28 void prefetch(unsigned char *sha1)
  29 {
  30         char type = 'o';
  31         struct object_list *node;
  32         if (prefetches > 100) {
  33                 fetch(in_transit->item->sha1);
  34         }
  35         node = xmalloc(sizeof(struct object_list));
  36         node->next = NULL;
  37         node->item = lookup_unknown_object(sha1);
  38         *end_of_transit = node;
  39         end_of_transit = &node->next;
  40         /* XXX: what if these writes fail? */
  41         write_in_full(fd_out, &type, 1);
  42         write_in_full(fd_out, sha1, 20);
  43         prefetches++;
  44 }
  45
  46 static char conn_buf[4096];
  47 static size_t conn_buf_posn;
  48
  49 int fetch(unsigned char *sha1)
  50 {
  51         int ret;
  52         signed char remote;
  53         struct object_list *temp;
  54
  55         if (hashcmp(sha1, in_transit->item->sha1)) {
  56                 /* we must have already fetched it to clean the queue */
  57                 return has_sha1_file(sha1) ? 0 : -1;
  58         }
  59         prefetches--;
  60         temp = in_transit;
  61         in_transit = in_transit->next;
  62         if (!in_transit)
  63                 end_of_transit = &in_transit;
  64         free(temp);
  65
  66         if (conn_buf_posn) {
  67                 remote = conn_buf[0];
  68                 memmove(conn_buf, conn_buf + 1, --conn_buf_posn);
  69         } else {
  70                 if (xread(fd_in, &remote, 1) < 1)
  71                         return -1;
  72         }
  73         /* fprintf(stderr, "Got %d\n", remote); */
  74         if (remote < 0)
  75                 return remote;
  76         ret = write_sha1_from_fd(sha1, fd_in, conn_buf, 4096, &conn_buf_posn);
  77         if (!ret)
  78                 pull_say("got %s\n", sha1_to_hex(sha1));
  79         return ret;
  80 }
  81
  82 static int get_version(void)
  83 {
  84         char type = 'v';
  85         if (write_in_full(fd_out, &type, 1) != 1 ||
  86             write_in_full(fd_out, &local_version, 1)) {
  87                 return error("Couldn't request version from remote end");
  88         }
  89         if (xread(fd_in, &remote_version, 1) < 1) {
  90                 return error("Couldn't read version from remote end");
  91         }
  92         return 0;
  93 }
  94
  95 int fetch_ref(char *ref, unsigned char *sha1)
  96 {
  97         signed char remote;
  98         char type = 'r';
  99         int length = strlen(ref) + 1;
 100         if (write_in_full(fd_out, &type, 1) != 1 ||
 101             write_in_full(fd_out, ref, length) != length)
 102                 return -1;
 103
 104         if (read_in_full(fd_in, &remote, 1) != 1)
 105                 return -1;
 106         if (remote < 0)
 107                 return remote;
 108         if (read_in_full(fd_in, sha1, 20) != 20)
 109                 return -1;
 110         return 0;
 111 }
 112
 113 static const char ssh_fetch_usage[] =
 114   MY_PROGRAM_NAME
 115   " [-c] [-t] [-a] [-v] [--recover] [-w ref] commit-id url";
 116 int main(int argc, char **argv)
 117 {
 118         const char *write_ref = NULL;
 119         char *commit_id;
 120         char *url;
 121         int arg = 1;
 122         const char *prog;
 123
 124         prog = getenv("GIT_SSH_PUSH");
 125         if (!prog) prog = "git-ssh-upload";
 126
 127         setup_ident();
 128         setup_git_directory();
 129         git_config(git_default_config);
 130
 131         while (arg < argc && argv[arg][0] == '-') {
 132                 if (argv[arg][1] == 't') {
 133                         get_tree = 1;
 134                 } else if (argv[arg][1] == 'c') {
 135                         get_history = 1;
 136                 } else if (argv[arg][1] == 'a') {
 137                         get_all = 1;
 138                         get_tree = 1;
 139                         get_history = 1;
 140                 } else if (argv[arg][1] == 'v') {
 141                         get_verbosely = 1;
 142                 } else if (argv[arg][1] == 'w') {
 143                         write_ref = argv[arg + 1];
 144                         arg++;
 145                 } else if (!strcmp(argv[arg], "--recover")) {
 146                         get_recover = 1;
 147                 }
 148                 arg++;
 149         }
 150         if (argc < arg + 2) {
 151                 usage(ssh_fetch_usage);
 152                 return 1;
 153         }
 154         commit_id = argv[arg];
 155         url = argv[arg + 1];
 156
 157         if (setup_connection(&fd_in, &fd_out, prog, url, arg, argv + 1))
 158                 return 1;
 159
 160         if (get_version())
 161                 return 1;
 162
 163         if (pull(1, &commit_id, &write_ref, url))
 164                 return 1;
 165
 166         return 0;
 167 }