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 static int find_common(int fd[2], unsigned char *result_sha1,
  16                        struct ref *refs)
  17 {
  18         int fetching;
  19         static char line[1000];
  20         int count = 0, flushes = 0, retval;
  21         FILE *revs;
  22
  23         revs = popen("git-rev-list $(git-rev-parse --all)", "r");
  24         if (!revs)
  25                 die("unable to run 'git-rev-list'");
  26
  27         fetching = 0;
  28         for ( ; refs ; refs = refs->next) {
  29                 unsigned char *remote = refs->old_sha1;
  30                 unsigned char *local = refs->new_sha1;
  31
  32                 if (!memcmp(remote, local, 20))
  33                         continue;
  34                 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
  35                 fetching++;
  36         }
  37         packet_flush(fd[1]);
  38         if (!fetching)
  39                 return 1;
  40         flushes = 1;
  41         retval = -1;
  42         while (fgets(line, sizeof(line), revs) != NULL) {
  43                 unsigned char sha1[20];
  44                 if (get_sha1_hex(line, sha1))
  45                         die("git-fetch-pack: expected object name, got crud");
  46                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
  47                 if (verbose)
  48                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
  49                 if (!(31 & ++count)) {
  50                         packet_flush(fd[1]);
  51                         flushes++;
  52
  53                         /*
  54                          * We keep one window "ahead" of the other side, and
  55                          * will wait for an ACK only on the next one
  56                          */
  57                         if (count == 32)
  58                                 continue;
  59                         if (get_ack(fd[0], result_sha1)) {
  60                                 flushes = 0;
  61                                 retval = 0;
  62                                 if (verbose)
  63                                         fprintf(stderr, "got ack\n");
  64                                 break;
  65                         }
  66                         flushes--;
  67                 }
  68         }
  69         pclose(revs);
  70         packet_write(fd[1], "done\n");
  71         if (verbose)
  72                 fprintf(stderr, "done\n");
  73         while (flushes) {
  74                 flushes--;
  75                 if (get_ack(fd[0], result_sha1)) {
  76                         if (verbose)
  77                                 fprintf(stderr, "got ack\n");
  78                         return 0;
  79                 }
  80         }
  81         return retval;
  82 }
  83
  84 #define COMPLETE        (1U << 0)
  85 static struct commit_list *complete = NULL;
  86
  87 static int mark_complete(const char *path, const unsigned char *sha1)
  88 {
  89         struct object *o = parse_object(sha1);
  90
  91         while (o && o->type == tag_type) {
  92                 o->flags |= COMPLETE;
  93                 o = parse_object(((struct tag *)o)->tagged->sha1);
  94         }
  95         if (o->type == commit_type) {
  96                 struct commit *commit = (struct commit *)o;
  97                 commit->object.flags |= COMPLETE;
  98                 insert_by_date(commit, &complete);
  99         }
 100         return 0;
 101 }
 102
 103 static void mark_recent_complete_commits(unsigned long cutoff)
 104 {
 105         while (complete && cutoff <= complete->item->date) {
 106                 if (verbose)
 107                         fprintf(stderr, "Marking %s as complete\n",
 108                                 sha1_to_hex(complete->item->object.sha1));
 109                 pop_most_recent_commit(&complete, COMPLETE);
 110         }
 111 }
 112
 113 static int everything_local(struct ref *refs)
 114 {
 115         struct ref *ref;
 116         int retval;
 117         unsigned long cutoff = 0;
 118
 119         track_object_refs = 0;
 120         save_commit_buffer = 0;
 121
 122         for (ref = refs; ref; ref = ref->next) {
 123                 struct object *o;
 124
 125                 o = parse_object(ref->old_sha1);
 126                 if (!o)
 127                         continue;
 128
 129                 /* We already have it -- which may mean that we were
 130                  * in sync with the other side at some time after
 131                  * that (it is OK if we guess wrong here).
 132                  */
 133                 if (o->type == commit_type) {
 134                         struct commit *commit = (struct commit *)o;
 135                         if (!cutoff || cutoff < commit->date)
 136                                 cutoff = commit->date;
 137                 }
 138         }
 139
 140         for_each_ref(mark_complete);
 141         if (cutoff)
 142                 mark_recent_complete_commits(cutoff);
 143
 144         for (retval = 1; refs ; refs = refs->next) {
 145                 const unsigned char *remote = refs->old_sha1;
 146                 unsigned char local[20];
 147                 struct object *o;
 148
 149                 o = parse_object(remote);
 150                 if (!o || !(o->flags & COMPLETE)) {
 151                         retval = 0;
 152                         if (!verbose)
 153                                 continue;
 154                         fprintf(stderr,
 155                                 "want %s (%s)\n", sha1_to_hex(remote),
 156                                 refs->name);
 157                         continue;
 158                 }
 159
 160                 memcpy(refs->new_sha1, local, 20);
 161                 if (!verbose)
 162                         continue;
 163                 fprintf(stderr,
 164                         "already have %s (%s)\n", sha1_to_hex(remote),
 165                         refs->name);
 166         }
 167         return retval;
 168 }
 169
 170 static int fetch_pack(int fd[2], int nr_match, char **match)
 171 {
 172         struct ref *ref;
 173         unsigned char sha1[20];
 174         int status;
 175         pid_t pid;
 176
 177         get_remote_heads(fd[0], &ref, nr_match, match, 1);
 178         if (!ref) {
 179                 packet_flush(fd[1]);
 180                 die("no matching remote head");
 181         }
 182         if (everything_local(ref)) {
 183                 packet_flush(fd[1]);
 184                 goto all_done;
 185         }
 186         if (find_common(fd, sha1, ref) < 0)
 187                 fprintf(stderr, "warning: no common commits\n");
 188         pid = fork();
 189         if (pid < 0)
 190                 die("git-fetch-pack: unable to fork off git-unpack-objects");
 191         if (!pid) {
 192                 dup2(fd[0], 0);
 193                 close(fd[0]);
 194                 close(fd[1]);
 195                 execlp("git-unpack-objects", "git-unpack-objects",
 196                        quiet ? "-q" : NULL, NULL);
 197                 die("git-unpack-objects exec failed");
 198         }
 199         close(fd[0]);
 200         close(fd[1]);
 201         while (waitpid(pid, &status, 0) < 0) {
 202                 if (errno != EINTR)
 203                         die("waiting for git-unpack-objects: %s", strerror(errno));
 204         }
 205         if (WIFEXITED(status)) {
 206                 int code = WEXITSTATUS(status);
 207                 if (code)
 208                         die("git-unpack-objects died with error code %d", code);
 209 all_done:
 210                 while (ref) {
 211                         printf("%s %s\n",
 212                                sha1_to_hex(ref->old_sha1), ref->name);
 213                         ref = ref->next;
 214                 }
 215                 return 0;
 216         }
 217         if (WIFSIGNALED(status)) {
 218                 int sig = WTERMSIG(status);
 219                 die("git-unpack-objects died of signal %d", sig);
 220         }
 221         die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 222 }
 223
 224 int main(int argc, char **argv)
 225 {
 226         int i, ret, nr_heads;
 227         char *dest = NULL, **heads;
 228         int fd[2];
 229         pid_t pid;
 230
 231         nr_heads = 0;
 232         heads = NULL;
 233         for (i = 1; i < argc; i++) {
 234                 char *arg = argv[i];
 235
 236                 if (*arg == '-') {
 237                         if (!strncmp("--exec=", arg, 7)) {
 238                                 exec = arg + 7;
 239                                 continue;
 240                         }
 241                         if (!strcmp("-q", arg)) {
 242                                 quiet = 1;
 243                                 continue;
 244                         }
 245                         if (!strcmp("-v", arg)) {
 246                                 verbose = 1;
 247                                 continue;
 248                         }
 249                         usage(fetch_pack_usage);
 250                 }
 251                 dest = arg;
 252                 heads = argv + i + 1;
 253                 nr_heads = argc - i - 1;
 254                 break;
 255         }
 256         if (!dest)
 257                 usage(fetch_pack_usage);
 258         pid = git_connect(fd, dest, exec);
 259         if (pid < 0)
 260                 return 1;
 261         ret = fetch_pack(fd, nr_heads, heads);
 262         close(fd[0]);
 263         close(fd[1]);
 264         finish_connect(pid);
 265         return ret;
 266 }