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 = 0;
  21 static unsigned char local_version = 1;
  22
  23 static ssize_t force_write(int fd, void *buffer, size_t length)
  24 {
  25         ssize_t ret = 0;
  26         while (ret < length) {
  27                 ssize_t size = write(fd, buffer + ret, length - ret);
  28                 if (size < 0) {
  29                         return size;
  30                 }
  31                 if (size == 0) {
  32                         return ret;
  33                 }
  34                 ret += size;
  35         }
  36         return ret;
  37 }
  38
  39 static int prefetches = 0;
  40
  41 static struct object_list *in_transit = NULL;
  42 static struct object_list **end_of_transit = &in_transit;
  43
  44 void prefetch(unsigned char *sha1)
  45 {
  46         char type = 'o';
  47         struct object_list *node;
  48         if (prefetches > 100) {
  49                 fetch(in_transit->item->sha1);
  50         }
  51         node = xmalloc(sizeof(struct object_list));
  52         node->next = NULL;
  53         node->item = lookup_unknown_object(sha1);
  54         *end_of_transit = node;
  55         end_of_transit = &node->next;
  56         force_write(fd_out, &type, 1);
  57         force_write(fd_out, sha1, 20);
  58         prefetches++;
  59 }
  60
  61 static char conn_buf[4096];
  62 static size_t conn_buf_posn = 0;
  63
  64 int fetch(unsigned char *sha1)
  65 {
  66         int ret;
  67         signed char remote;
  68         struct object_list *temp;
  69
  70         if (memcmp(sha1, in_transit->item->sha1, 20)) {
  71                 // we must have already fetched it to clean the queue
  72                 return has_sha1_file(sha1) ? 0 : -1;
  73         }
  74         prefetches--;
  75         temp = in_transit;
  76         in_transit = in_transit->next;
  77         if (!in_transit)
  78                 end_of_transit = &in_transit;
  79         free(temp);
  80
  81         if (conn_buf_posn) {
  82                 remote = conn_buf[0];
  83                 memmove(conn_buf, conn_buf + 1, --conn_buf_posn);
  84         } else {
  85                 if (read(fd_in, &remote, 1) < 1)
  86                         return -1;
  87         }
  88         //fprintf(stderr, "Got %d\n", remote);
  89         if (remote < 0)
  90                 return remote;
  91         ret = write_sha1_from_fd(sha1, fd_in, conn_buf, 4096, &conn_buf_posn);
  92         if (!ret)
  93                 pull_say("got %s\n", sha1_to_hex(sha1));
  94         return ret;
  95 }
  96
  97 static int get_version(void)
  98 {
  99         char type = 'v';
 100         write(fd_out, &type, 1);
 101         write(fd_out, &local_version, 1);
 102         if (read(fd_in, &remote_version, 1) < 1) {
 103                 return error("Couldn't read version from remote end");
 104         }
 105         return 0;
 106 }
 107
 108 int fetch_ref(char *ref, unsigned char *sha1)
 109 {
 110         signed char remote;
 111         char type = 'r';
 112         write(fd_out, &type, 1);
 113         write(fd_out, ref, strlen(ref) + 1);
 114         read(fd_in, &remote, 1);
 115         if (remote < 0)
 116                 return remote;
 117         read(fd_in, sha1, 20);
 118         return 0;
 119 }
 120
 121 static const char ssh_fetch_usage[] =
 122   MY_PROGRAM_NAME
 123   " [-c] [-t] [-a] [-v] [-d] [--recover] [-w ref] commit-id url";
 124 int main(int argc, char **argv)
 125 {
 126         char *commit_id;
 127         char *url;
 128         int arg = 1;
 129         const char *prog;
 130
 131         prog = getenv("GIT_SSH_PUSH");
 132         if (!prog) prog = "git-ssh-upload";
 133
 134         setup_git_directory();
 135
 136         while (arg < argc && argv[arg][0] == '-') {
 137                 if (argv[arg][1] == 't') {
 138                         get_tree = 1;
 139                 } else if (argv[arg][1] == 'c') {
 140                         get_history = 1;
 141                 } else if (argv[arg][1] == 'a') {
 142                         get_all = 1;
 143                         get_tree = 1;
 144                         get_history = 1;
 145                 } else if (argv[arg][1] == 'v') {
 146                         get_verbosely = 1;
 147                 } else if (argv[arg][1] == 'w') {
 148                         write_ref = argv[arg + 1];
 149                         arg++;
 150                 } else if (!strcmp(argv[arg], "--recover")) {
 151                         get_recover = 1;
 152                 }
 153                 arg++;
 154         }
 155         if (argc < arg + 2) {
 156                 usage(ssh_fetch_usage);
 157                 return 1;
 158         }
 159         commit_id = argv[arg];
 160         url = argv[arg + 1];
 161
 162         if (setup_connection(&fd_in, &fd_out, prog, url, arg, argv + 1))
 163                 return 1;
 164
 165         if (get_version())
 166                 return 1;
 167
 168         if (pull(commit_id))
 169                 return 1;
 170
 171         return 0;
 172 }