fetch-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "commit.h"
   5 #include "tag.h"
   6 #include <time.h>
   7 #include <sys/wait.h>
   8
   9 static int quiet;
  10 static int verbose;
  11 static const char fetch_pack_usage[] =
  12 "git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
  13 static const char *exec = "git-upload-pack";
  14
  15 #define COMPLETE        (1U << 0)
  16
  17 static int find_common(int fd[2], unsigned char *result_sha1,
  18                        struct ref *refs)
  19 {
  20         int fetching;
  21         static char line[1000];
  22         static char rev_command[1024];
  23         int count = 0, flushes = 0, retval, rev_command_len;
  24         FILE *revs;
  25
  26         strcpy(rev_command, "git-rev-list $(git-rev-parse --all)");
  27         rev_command_len = strlen(rev_command);
  28         fetching = 0;
  29         for ( ; refs ; refs = refs->next) {
  30                 unsigned char *remote = refs->old_sha1;
  31
  32                 /*
  33                    If that object is complete (i.e. it is a descendant of a
  34                    local ref), we don't want it, nor its descendants.
  35                 */
  36                 if (has_sha1_file(remote)
  37                                 && parse_object(remote)->flags & COMPLETE) {
  38                         if (rev_command_len + 44 < sizeof(rev_command)) {
  39                                 snprintf(rev_command + rev_command_len, 44,
  40                                         " ^%s^", sha1_to_hex(remote));
  41                                 rev_command_len += 43;
  42                         }
  43
  44                         continue;
  45                 }
  46
  47                 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
  48                 fetching++;
  49         }
  50         packet_flush(fd[1]);
  51         if (!fetching)
  52                 return 1;
  53
  54         revs = popen(rev_command, "r");
  55         if (!revs)
  56                 die("unable to run 'git-rev-list'");
  57
  58         flushes = 1;
  59         retval = -1;
  60         while (fgets(line, sizeof(line), revs) != NULL) {
  61                 unsigned char sha1[20];
  62                 if (get_sha1_hex(line, sha1))
  63                         die("git-fetch-pack: expected object name, got crud");
  64                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
  65                 if (verbose)
  66                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
  67                 if (!(31 & ++count)) {
  68                         packet_flush(fd[1]);
  69                         flushes++;
  70
  71                         /*
  72                          * We keep one window "ahead" of the other side, and
  73                          * will wait for an ACK only on the next one
  74                          */
  75                         if (count == 32)
  76                                 continue;
  77                         if (get_ack(fd[0], result_sha1)) {
  78                                 flushes = 0;
  79                                 retval = 0;
  80                                 if (verbose)
  81                                         fprintf(stderr, "got ack\n");
  82                                 break;
  83                         }
  84                         flushes--;
  85                 }
  86         }
  87         pclose(revs);
  88         packet_write(fd[1], "done\n");
  89         if (verbose)
  90                 fprintf(stderr, "done\n");
  91         while (flushes) {
  92                 flushes--;
  93                 if (get_ack(fd[0], result_sha1)) {
  94                         if (verbose)
  95                                 fprintf(stderr, "got ack\n");
  96                         return 0;
  97                 }
  98         }
  99         return retval;
 100 }
 101
 102 static struct commit_list *complete = NULL;
 103
 104 static int mark_complete(const char *path, const unsigned char *sha1)
 105 {
 106         struct object *o = parse_object(sha1);
 107
 108         while (o && o->type == tag_type) {
 109                 o->flags |= COMPLETE;
 110                 o = parse_object(((struct tag *)o)->tagged->sha1);
 111         }
 112         if (o->type == commit_type) {
 113                 struct commit *commit = (struct commit *)o;
 114                 commit->object.flags |= COMPLETE;
 115                 insert_by_date(commit, &complete);
 116         }
 117         return 0;
 118 }
 119
 120 static void mark_recent_complete_commits(unsigned long cutoff)
 121 {
 122         while (complete && cutoff <= complete->item->date) {
 123                 if (verbose)
 124                         fprintf(stderr, "Marking %s as complete\n",
 125                                 sha1_to_hex(complete->item->object.sha1));
 126                 pop_most_recent_commit(&complete, COMPLETE);
 127         }
 128 }
 129
 130 static int everything_local(struct ref *refs)
 131 {
 132         struct ref *ref;
 133         int retval;
 134         unsigned long cutoff = 0;
 135
 136         track_object_refs = 0;
 137         save_commit_buffer = 0;
 138
 139         for (ref = refs; ref; ref = ref->next) {
 140                 struct object *o;
 141
 142                 o = parse_object(ref->old_sha1);
 143                 if (!o)
 144                         continue;
 145
 146                 /* We already have it -- which may mean that we were
 147                  * in sync with the other side at some time after
 148                  * that (it is OK if we guess wrong here).
 149                  */
 150                 if (o->type == commit_type) {
 151                         struct commit *commit = (struct commit *)o;
 152                         if (!cutoff || cutoff < commit->date)
 153                                 cutoff = commit->date;
 154                 }
 155         }
 156
 157         for_each_ref(mark_complete);
 158         if (cutoff)
 159                 mark_recent_complete_commits(cutoff);
 160
 161         for (retval = 1; refs ; refs = refs->next) {
 162                 const unsigned char *remote = refs->old_sha1;
 163                 unsigned char local[20];
 164                 struct object *o;
 165
 166                 o = parse_object(remote);
 167                 if (!o || !(o->flags & COMPLETE)) {
 168                         retval = 0;
 169                         if (!verbose)
 170                                 continue;
 171                         fprintf(stderr,
 172                                 "want %s (%s)\n", sha1_to_hex(remote),
 173                                 refs->name);
 174                         continue;
 175                 }
 176
 177                 memcpy(refs->new_sha1, local, 20);
 178                 if (!verbose)
 179                         continue;
 180                 fprintf(stderr,
 181                         "already have %s (%s)\n", sha1_to_hex(remote),
 182                         refs->name);
 183         }
 184         return retval;
 185 }
 186
 187 static int fetch_pack(int fd[2], int nr_match, char **match)
 188 {
 189         struct ref *ref;
 190         unsigned char sha1[20];
 191         int status;
 192         pid_t pid;
 193
 194         get_remote_heads(fd[0], &ref, nr_match, match, 1);
 195         if (!ref) {
 196                 packet_flush(fd[1]);
 197                 die("no matching remote head");
 198         }
 199         if (everything_local(ref)) {
 200                 packet_flush(fd[1]);
 201                 goto all_done;
 202         }
 203         if (find_common(fd, sha1, ref) < 0)
 204                 fprintf(stderr, "warning: no common commits\n");
 205         pid = fork();
 206         if (pid < 0)
 207                 die("git-fetch-pack: unable to fork off git-unpack-objects");
 208         if (!pid) {
 209                 dup2(fd[0], 0);
 210                 close(fd[0]);
 211                 close(fd[1]);
 212                 execlp("git-unpack-objects", "git-unpack-objects",
 213                        quiet ? "-q" : NULL, NULL);
 214                 die("git-unpack-objects exec failed");
 215         }
 216         close(fd[0]);
 217         close(fd[1]);
 218         while (waitpid(pid, &status, 0) < 0) {
 219                 if (errno != EINTR)
 220                         die("waiting for git-unpack-objects: %s", strerror(errno));
 221         }
 222         if (WIFEXITED(status)) {
 223                 int code = WEXITSTATUS(status);
 224                 if (code)
 225                         die("git-unpack-objects died with error code %d", code);
 226 all_done:
 227                 while (ref) {
 228                         printf("%s %s\n",
 229                                sha1_to_hex(ref->old_sha1), ref->name);
 230                         ref = ref->next;
 231                 }
 232                 return 0;
 233         }
 234         if (WIFSIGNALED(status)) {
 235                 int sig = WTERMSIG(status);
 236                 die("git-unpack-objects died of signal %d", sig);
 237         }
 238         die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 239 }
 240
 241 int main(int argc, char **argv)
 242 {
 243         int i, ret, nr_heads;
 244         char *dest = NULL, **heads;
 245         int fd[2];
 246         pid_t pid;
 247
 248         nr_heads = 0;
 249         heads = NULL;
 250         for (i = 1; i < argc; i++) {
 251                 char *arg = argv[i];
 252
 253                 if (*arg == '-') {
 254                         if (!strncmp("--exec=", arg, 7)) {
 255                                 exec = arg + 7;
 256                                 continue;
 257                         }
 258                         if (!strcmp("-q", arg)) {
 259                                 quiet = 1;
 260                                 continue;
 261                         }
 262                         if (!strcmp("-v", arg)) {
 263                                 verbose = 1;
 264                                 continue;
 265                         }
 266                         usage(fetch_pack_usage);
 267                 }
 268                 dest = arg;
 269                 heads = argv + i + 1;
 270                 nr_heads = argc - i - 1;
 271                 break;
 272         }
 273         if (!dest)
 274                 usage(fetch_pack_usage);
 275         pid = git_connect(fd, dest, exec);
 276         if (pid < 0)
 277                 return 1;
 278         ret = fetch_pack(fd, nr_heads, heads);
 279         close(fd[0]);
 280         close(fd[1]);
 281         finish_connect(pid);
 282         return ret;
 283 }