fetch-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include <sys/wait.h>
   5
   6 static int quiet;
   7 static int verbose;
   8 static const char fetch_pack_usage[] =
   9 "git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
  10 static const char *exec = "git-upload-pack";
  11
  12 static int find_common(int fd[2], unsigned char *result_sha1,
  13                        struct ref *refs)
  14 {
  15         static char line[1000];
  16         int count = 0, flushes = 0, retval;
  17         FILE *revs;
  18
  19         revs = popen("git-rev-list $(git-rev-parse --all)", "r");
  20         if (!revs)
  21                 die("unable to run 'git-rev-list'");
  22
  23         while (refs) {
  24                 unsigned char *remote = refs->old_sha1;
  25                 if (verbose)
  26                         fprintf(stderr,
  27                                 "want %s (%s)\n", sha1_to_hex(remote),
  28                                 refs->name);
  29                 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
  30                 refs = refs->next;
  31         }
  32         packet_flush(fd[1]);
  33         flushes = 1;
  34         retval = -1;
  35         while (fgets(line, sizeof(line), revs) != NULL) {
  36                 unsigned char sha1[20];
  37                 if (get_sha1_hex(line, sha1))
  38                         die("git-fetch-pack: expected object name, got crud");
  39                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
  40                 if (verbose)
  41                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
  42                 if (!(31 & ++count)) {
  43                         packet_flush(fd[1]);
  44                         flushes++;
  45
  46                         /*
  47                          * We keep one window "ahead" of the other side, and
  48                          * will wait for an ACK only on the next one
  49                          */
  50                         if (count == 32)
  51                                 continue;
  52                         if (get_ack(fd[0], result_sha1)) {
  53                                 flushes = 0;
  54                                 retval = 0;
  55                                 if (verbose)
  56                                         fprintf(stderr, "got ack\n");
  57                                 break;
  58                         }
  59                         flushes--;
  60                 }
  61         }
  62         pclose(revs);
  63         packet_write(fd[1], "done\n");
  64         if (verbose)
  65                 fprintf(stderr, "done\n");
  66         while (flushes) {
  67                 flushes--;
  68                 if (get_ack(fd[0], result_sha1)) {
  69                         if (verbose)
  70                                 fprintf(stderr, "got ack\n");
  71                         return 0;
  72                 }
  73         }
  74         return retval;
  75 }
  76
  77 static int fetch_pack(int fd[2], int nr_match, char **match)
  78 {
  79         struct ref *ref;
  80         unsigned char sha1[20];
  81         int status;
  82         pid_t pid;
  83
  84         get_remote_heads(fd[0], &ref, nr_match, match, 1);
  85         if (!ref) {
  86                 packet_flush(fd[1]);
  87                 die("no matching remote head");
  88         }
  89         if (find_common(fd, sha1, ref) < 0)
  90                 fprintf(stderr, "warning: no common commits\n");
  91         pid = fork();
  92         if (pid < 0)
  93                 die("git-fetch-pack: unable to fork off git-unpack-objects");
  94         if (!pid) {
  95                 dup2(fd[0], 0);
  96                 close(fd[0]);
  97                 close(fd[1]);
  98                 execlp("git-unpack-objects", "git-unpack-objects",
  99                        quiet ? "-q" : NULL, NULL);
 100                 die("git-unpack-objects exec failed");
 101         }
 102         close(fd[0]);
 103         close(fd[1]);
 104         while (waitpid(pid, &status, 0) < 0) {
 105                 if (errno != EINTR)
 106                         die("waiting for git-unpack-objects: %s", strerror(errno));
 107         }
 108         if (WIFEXITED(status)) {
 109                 int code = WEXITSTATUS(status);
 110                 if (code)
 111                         die("git-unpack-objects died with error code %d", code);
 112                 while (ref) {
 113                         printf("%s %s\n",
 114                                sha1_to_hex(ref->old_sha1), ref->name);
 115                         ref = ref->next;
 116                 }
 117                 return 0;
 118         }
 119         if (WIFSIGNALED(status)) {
 120                 int sig = WTERMSIG(status);
 121                 die("git-unpack-objects died of signal %d", sig);
 122         }
 123         die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 124 }
 125
 126 int main(int argc, char **argv)
 127 {
 128         int i, ret, nr_heads;
 129         char *dest = NULL, **heads;
 130         int fd[2];
 131         pid_t pid;
 132
 133         nr_heads = 0;
 134         heads = NULL;
 135         for (i = 1; i < argc; i++) {
 136                 char *arg = argv[i];
 137
 138                 if (*arg == '-') {
 139                         if (!strncmp("--exec=", arg, 7)) {
 140                                 exec = arg + 7;
 141                                 continue;
 142                         }
 143                         if (!strcmp("-q", arg)) {
 144                                 quiet = 1;
 145                                 continue;
 146                         }
 147                         if (!strcmp("-v", arg)) {
 148                                 verbose = 1;
 149                                 continue;
 150                         }
 151                         usage(fetch_pack_usage);
 152                 }
 153                 dest = arg;
 154                 heads = argv + i + 1;
 155                 nr_heads = argc - i - 1;
 156                 break;
 157         }
 158         if (!dest)
 159                 usage(fetch_pack_usage);
 160         pid = git_connect(fd, dest, exec);
 161         if (pid < 0)
 162                 return 1;
 163         ret = fetch_pack(fd, nr_heads, heads);
 164         close(fd[0]);
 165         close(fd[1]);
 166         finish_connect(pid);
 167         return ret;
 168 }