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                 struct object *o;
  32
  33                 /*
  34                  * If that object is complete (i.e. it is an ancestor of a
  35                  * local ref), we tell them we have it but do not have to
  36                  * tell them about its ancestors, which they already know
  37                  * about.
  38                  */
  39                 if (has_sha1_file(remote) &&
  40                     ((o = parse_object(remote)) != NULL) &&
  41                     (o->flags & COMPLETE)) {
  42                         struct commit_list *p;
  43                         struct commit *commit =
  44                                 (struct commit *) (o = deref_tag(o));
  45                         if (!o)
  46                                 goto repair;
  47                         if (o->type != commit_type)
  48                                 continue;
  49                         p = commit->parents;
  50                         while (p &&
  51                                rev_command_len + 44 < sizeof(rev_command)) {
  52                                 snprintf(rev_command + rev_command_len, 44,
  53                                          " ^%s",
  54                                          sha1_to_hex(p->item->object.sha1));
  55                                 rev_command_len += 43;
  56                                 p = p->next;
  57                         }
  58                         continue;
  59                 }
  60         repair:
  61                 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
  62                 fetching++;
  63         }
  64         packet_flush(fd[1]);
  65         if (!fetching)
  66                 return 1;
  67
  68         revs = popen(rev_command, "r");
  69         if (!revs)
  70                 die("unable to run 'git-rev-list'");
  71
  72         flushes = 1;
  73         retval = -1;
  74         while (fgets(line, sizeof(line), revs) != NULL) {
  75                 unsigned char sha1[20];
  76                 if (get_sha1_hex(line, sha1))
  77                         die("git-fetch-pack: expected object name, got crud");
  78                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
  79                 if (verbose)
  80                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
  81                 if (!(31 & ++count)) {
  82                         packet_flush(fd[1]);
  83                         flushes++;
  84
  85                         /*
  86                          * We keep one window "ahead" of the other side, and
  87                          * will wait for an ACK only on the next one
  88                          */
  89                         if (count == 32)
  90                                 continue;
  91                         if (get_ack(fd[0], result_sha1)) {
  92                                 flushes = 0;
  93                                 retval = 0;
  94                                 if (verbose)
  95                                         fprintf(stderr, "got ack\n");
  96                                 break;
  97                         }
  98                         flushes--;
  99                 }
 100         }
 101         pclose(revs);
 102         packet_write(fd[1], "done\n");
 103         if (verbose)
 104                 fprintf(stderr, "done\n");
 105         while (flushes) {
 106                 flushes--;
 107                 if (get_ack(fd[0], result_sha1)) {
 108                         if (verbose)
 109                                 fprintf(stderr, "got ack\n");
 110                         return 0;
 111                 }
 112         }
 113         return retval;
 114 }
 115
 116 static struct commit_list *complete = NULL;
 117
 118 static int mark_complete(const char *path, const unsigned char *sha1)
 119 {
 120         struct object *o = parse_object(sha1);
 121
 122         while (o && o->type == tag_type) {
 123                 o->flags |= COMPLETE;
 124                 o = parse_object(((struct tag *)o)->tagged->sha1);
 125         }
 126         if (o->type == commit_type) {
 127                 struct commit *commit = (struct commit *)o;
 128                 commit->object.flags |= COMPLETE;
 129                 insert_by_date(commit, &complete);
 130         }
 131         return 0;
 132 }
 133
 134 static void mark_recent_complete_commits(unsigned long cutoff)
 135 {
 136         while (complete && cutoff <= complete->item->date) {
 137                 if (verbose)
 138                         fprintf(stderr, "Marking %s as complete\n",
 139                                 sha1_to_hex(complete->item->object.sha1));
 140                 pop_most_recent_commit(&complete, COMPLETE);
 141         }
 142 }
 143
 144 static int everything_local(struct ref *refs)
 145 {
 146         struct ref *ref;
 147         int retval;
 148         unsigned long cutoff = 0;
 149
 150         track_object_refs = 0;
 151         save_commit_buffer = 0;
 152
 153         for (ref = refs; ref; ref = ref->next) {
 154                 struct object *o;
 155
 156                 o = parse_object(ref->old_sha1);
 157                 if (!o)
 158                         continue;
 159
 160                 /* We already have it -- which may mean that we were
 161                  * in sync with the other side at some time after
 162                  * that (it is OK if we guess wrong here).
 163                  */
 164                 if (o->type == commit_type) {
 165                         struct commit *commit = (struct commit *)o;
 166                         if (!cutoff || cutoff < commit->date)
 167                                 cutoff = commit->date;
 168                 }
 169         }
 170
 171         for_each_ref(mark_complete);
 172         if (cutoff)
 173                 mark_recent_complete_commits(cutoff);
 174
 175         for (retval = 1; refs ; refs = refs->next) {
 176                 const unsigned char *remote = refs->old_sha1;
 177                 unsigned char local[20];
 178                 struct object *o;
 179
 180                 o = parse_object(remote);
 181                 if (!o || !(o->flags & COMPLETE)) {
 182                         retval = 0;
 183                         if (!verbose)
 184                                 continue;
 185                         fprintf(stderr,
 186                                 "want %s (%s)\n", sha1_to_hex(remote),
 187                                 refs->name);
 188                         continue;
 189                 }
 190
 191                 memcpy(refs->new_sha1, local, 20);
 192                 if (!verbose)
 193                         continue;
 194                 fprintf(stderr,
 195                         "already have %s (%s)\n", sha1_to_hex(remote),
 196                         refs->name);
 197         }
 198         return retval;
 199 }
 200
 201 static int fetch_pack(int fd[2], int nr_match, char **match)
 202 {
 203         struct ref *ref;
 204         unsigned char sha1[20];
 205         int status;
 206         pid_t pid;
 207
 208         get_remote_heads(fd[0], &ref, nr_match, match, 1);
 209         if (!ref) {
 210                 packet_flush(fd[1]);
 211                 die("no matching remote head");
 212         }
 213         if (everything_local(ref)) {
 214                 packet_flush(fd[1]);
 215                 goto all_done;
 216         }
 217         if (find_common(fd, sha1, ref) < 0)
 218                 fprintf(stderr, "warning: no common commits\n");
 219         pid = fork();
 220         if (pid < 0)
 221                 die("git-fetch-pack: unable to fork off git-unpack-objects");
 222         if (!pid) {
 223                 dup2(fd[0], 0);
 224                 close(fd[0]);
 225                 close(fd[1]);
 226                 execlp("git-unpack-objects", "git-unpack-objects",
 227                        quiet ? "-q" : NULL, NULL);
 228                 die("git-unpack-objects exec failed");
 229         }
 230         close(fd[0]);
 231         close(fd[1]);
 232         while (waitpid(pid, &status, 0) < 0) {
 233                 if (errno != EINTR)
 234                         die("waiting for git-unpack-objects: %s", strerror(errno));
 235         }
 236         if (WIFEXITED(status)) {
 237                 int code = WEXITSTATUS(status);
 238                 if (code)
 239                         die("git-unpack-objects died with error code %d", code);
 240 all_done:
 241                 while (ref) {
 242                         printf("%s %s\n",
 243                                sha1_to_hex(ref->old_sha1), ref->name);
 244                         ref = ref->next;
 245                 }
 246                 return 0;
 247         }
 248         if (WIFSIGNALED(status)) {
 249                 int sig = WTERMSIG(status);
 250                 die("git-unpack-objects died of signal %d", sig);
 251         }
 252         die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 253 }
 254
 255 int main(int argc, char **argv)
 256 {
 257         int i, ret, nr_heads;
 258         char *dest = NULL, **heads;
 259         int fd[2];
 260         pid_t pid;
 261
 262         nr_heads = 0;
 263         heads = NULL;
 264         for (i = 1; i < argc; i++) {
 265                 char *arg = argv[i];
 266
 267                 if (*arg == '-') {
 268                         if (!strncmp("--exec=", arg, 7)) {
 269                                 exec = arg + 7;
 270                                 continue;
 271                         }
 272                         if (!strcmp("-q", arg)) {
 273                                 quiet = 1;
 274                                 continue;
 275                         }
 276                         if (!strcmp("-v", arg)) {
 277                                 verbose = 1;
 278                                 continue;
 279                         }
 280                         usage(fetch_pack_usage);
 281                 }
 282                 dest = arg;
 283                 heads = argv + i + 1;
 284                 nr_heads = argc - i - 1;
 285                 break;
 286         }
 287         if (!dest)
 288                 usage(fetch_pack_usage);
 289         pid = git_connect(fd, dest, exec);
 290         if (pid < 0)
 291                 return 1;
 292         ret = fetch_pack(fd, nr_heads, heads);
 293         close(fd[0]);
 294         close(fd[1]);
 295         finish_connect(pid);
 296         return ret;
 297 }