Andrew's git - gitweb.git/blob

57602b9561160a3ff14b893a92d69b46c1ffa9df
   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
   9static int quiet;
  10static int verbose;
  11static const char fetch_pack_usage[] =
  12"git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
  13static const char *exec = "git-upload-pack";
  14
  15#define COMPLETE        (1U << 0)
  16#define COMMON          (1U << 1)
  17#define COMMON_REF      (1U << 2 | COMMON)
  18#define SEEN            (1U << 3)
  19#define POPPED          (1U << 4)
  20
  21static struct commit_list *rev_list = NULL;
  22static struct commit_list *rev_list_end = NULL;
  23static unsigned long non_common_revs = 0;
  24
  25static void rev_list_append(struct commit *commit, int mark)
  26{
  27        if (!(commit->object.flags & mark)) {
  28                commit->object.flags |= mark;
  29
  30                if (rev_list == NULL) {
  31                        commit_list_insert(commit, &rev_list);
  32                        rev_list_end = rev_list;
  33                } else {
  34                        commit_list_insert(commit, &(rev_list_end->next));
  35                        rev_list_end = rev_list_end->next;
  36                }
  37
  38                if (!(commit->object.flags & COMMON))
  39                        non_common_revs++;
  40        }
  41}
  42
  43static int rev_list_append_sha1(const char *path, const unsigned char *sha1)
  44{
  45        struct object *o = deref_tag(parse_object(sha1));
  46
  47        if (o->type == commit_type)
  48                rev_list_append((struct commit *)o, SEEN);
  49
  50        return 0;
  51}
  52
  53static void mark_common(struct commit *commit)
  54{
  55        if (commit != NULL && !(commit->object.flags & COMMON)) {
  56                struct object *o = (struct object *)commit;
  57                o->flags |= COMMON;
  58                if (!(o->flags & SEEN))
  59                        rev_list_append(commit, SEEN);
  60                else {
  61                        struct commit_list *parents;
  62
  63                        if (!(o->flags & POPPED))
  64                                non_common_revs--;
  65                        if (!o->parsed)
  66                                parse_commit(commit);
  67                        for (parents = commit->parents;
  68                                        parents;
  69                                        parents = parents->next)
  70                                mark_common(parents->item);
  71                }
  72        }
  73}
  74
  75/*
  76  Get the next rev to send, ignoring the common.
  77*/
  78
  79static const unsigned char* get_rev()
  80{
  81        struct commit *commit = NULL;
  82
  83        while (commit == NULL) {
  84                unsigned int mark;
  85                struct commit_list* parents;
  86
  87                if (rev_list == NULL || non_common_revs == 0)
  88                        return NULL;
  89
  90                commit = rev_list->item;
  91                if (!(commit->object.parsed))
  92                        parse_commit(commit);
  93                commit->object.flags |= POPPED;
  94                if (!(commit->object.flags & COMMON))
  95                        non_common_revs--;
  96        
  97                parents = commit->parents;
  98
  99                if (commit->object.flags & COMMON) {
 100                        /* do not send "have", and ignore ancestors */
 101                        commit = NULL;
 102                        mark = COMMON | SEEN;
 103                } else if (commit->object.flags & COMMON_REF)
 104                        /* send "have", and ignore ancestors */
 105                        mark = COMMON | SEEN;
 106                else
 107                        /* send "have", also for its ancestors */
 108                        mark = SEEN;
 109
 110                while (parents) {
 111                        if (mark & COMMON)
 112                                mark_common(parents->item);
 113                        else
 114                                rev_list_append(parents->item, mark);
 115                        parents = parents->next;
 116                }
 117
 118                rev_list = rev_list->next;
 119        }
 120
 121        return commit->object.sha1;
 122}
 123
 124static int find_common(int fd[2], unsigned char *result_sha1,
 125                       struct ref *refs)
 126{
 127        int fetching;
 128        int count = 0, flushes = 0, multi_ack = 0, retval;
 129        const unsigned char *sha1;
 130
 131        for_each_ref(rev_list_append_sha1);
 132
 133        fetching = 0;
 134        for ( ; refs ; refs = refs->next) {
 135                unsigned char *remote = refs->old_sha1;
 136                struct object *o;
 137
 138                /*
 139                 * If that object is complete (i.e. it is an ancestor of a
 140                 * local ref), we tell them we have it but do not have to
 141                 * tell them about its ancestors, which they already know
 142                 * about.
 143                 *
 144                 * We use lookup_object here because we are only
 145                 * interested in the case we *know* the object is
 146                 * reachable and we have already scanned it.
 147                 */
 148                if (((o = lookup_object(remote)) != NULL) &&
 149                    (o->flags & COMPLETE)) {
 150                        o = deref_tag(o);
 151
 152                        if (o->type == commit_type)
 153                                rev_list_append((struct commit *)o,
 154                                                COMMON_REF | SEEN);
 155
 156                        continue;
 157                }
 158
 159                packet_write(fd[1], "want %s multi_ack\n", sha1_to_hex(remote));
 160                fetching++;
 161        }
 162        packet_flush(fd[1]);
 163        if (!fetching)
 164                return 1;
 165
 166        flushes = 0;
 167        retval = -1;
 168        while ((sha1 = get_rev())) {
 169                packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
 170                if (verbose)
 171                        fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 172                if (!(31 & ++count)) {
 173                        int ack;
 174
 175                        packet_flush(fd[1]);
 176                        flushes++;
 177
 178                        /*
 179                         * We keep one window "ahead" of the other side, and
 180                         * will wait for an ACK only on the next one
 181                         */
 182                        if (count == 32)
 183                                continue;
 184
 185                        do {
 186                                ack = get_ack(fd[0], result_sha1);
 187                                if (verbose && ack)
 188                                        fprintf(stderr, "got ack %d %s\n", ack,
 189                                                        sha1_to_hex(result_sha1));
 190                                if (ack == 1) {
 191                                        if (!multi_ack)
 192                                                flushes = 0;
 193                                        retval = 0;
 194                                        goto done;
 195                                } else if (ack == 2) {
 196                                        multi_ack = 1;
 197                                        mark_common((struct commit *)
 198                                                        lookup_object(result_sha1));
 199                                        retval = 0;
 200                                }
 201                        } while(ack);
 202                        flushes--;
 203                }
 204        }
 205done:
 206        if (multi_ack) {
 207                packet_flush(fd[1]);
 208                flushes++;
 209        }
 210        packet_write(fd[1], "done\n");
 211        if (verbose)
 212                fprintf(stderr, "done\n");
 213        if (retval != 0)
 214                flushes++;
 215        while (flushes) {
 216                if (get_ack(fd[0], result_sha1)) {
 217                        if (verbose)
 218                                fprintf(stderr, "got ack %s\n",
 219                                        sha1_to_hex(result_sha1));
 220                        if (!multi_ack)
 221                                return 0;
 222                        retval = 0;
 223                        continue;
 224                }
 225                flushes--;
 226        }
 227        return retval;
 228}
 229
 230static struct commit_list *complete = NULL;
 231
 232static int mark_complete(const char *path, const unsigned char *sha1)
 233{
 234        struct object *o = parse_object(sha1);
 235
 236        while (o && o->type == tag_type) {
 237                struct tag *t = (struct tag *) o;
 238                if (!t->tagged)
 239                        break; /* broken repository */
 240                o->flags |= COMPLETE;
 241                o = parse_object(t->tagged->sha1);
 242        }
 243        if (o && o->type == commit_type) {
 244                struct commit *commit = (struct commit *)o;
 245                commit->object.flags |= COMPLETE;
 246                insert_by_date(commit, &complete);
 247        }
 248        return 0;
 249}
 250
 251static void mark_recent_complete_commits(unsigned long cutoff)
 252{
 253        while (complete && cutoff <= complete->item->date) {
 254                if (verbose)
 255                        fprintf(stderr, "Marking %s as complete\n",
 256                                sha1_to_hex(complete->item->object.sha1));
 257                pop_most_recent_commit(&complete, COMPLETE);
 258        }
 259}
 260
 261static int everything_local(struct ref *refs)
 262{
 263        struct ref *ref;
 264        int retval;
 265        unsigned long cutoff = 0;
 266
 267        track_object_refs = 0;
 268        save_commit_buffer = 0;
 269
 270        for (ref = refs; ref; ref = ref->next) {
 271                struct object *o;
 272
 273                o = parse_object(ref->old_sha1);
 274                if (!o)
 275                        continue;
 276
 277                /* We already have it -- which may mean that we were
 278                 * in sync with the other side at some time after
 279                 * that (it is OK if we guess wrong here).
 280                 */
 281                if (o->type == commit_type) {
 282                        struct commit *commit = (struct commit *)o;
 283                        if (!cutoff || cutoff < commit->date)
 284                                cutoff = commit->date;
 285                }
 286        }
 287
 288        for_each_ref(mark_complete);
 289        if (cutoff)
 290                mark_recent_complete_commits(cutoff);
 291
 292        for (retval = 1; refs ; refs = refs->next) {
 293                const unsigned char *remote = refs->old_sha1;
 294                unsigned char local[20];
 295                struct object *o;
 296
 297                o = parse_object(remote);
 298                if (!o || !(o->flags & COMPLETE)) {
 299                        retval = 0;
 300                        if (!verbose)
 301                                continue;
 302                        fprintf(stderr,
 303                                "want %s (%s)\n", sha1_to_hex(remote),
 304                                refs->name);
 305                        continue;
 306                }
 307
 308                memcpy(refs->new_sha1, local, 20);
 309                if (!verbose)
 310                        continue;
 311                fprintf(stderr,
 312                        "already have %s (%s)\n", sha1_to_hex(remote),
 313                        refs->name);
 314        }
 315        return retval;
 316}
 317
 318static int fetch_pack(int fd[2], int nr_match, char **match)
 319{
 320        struct ref *ref;
 321        unsigned char sha1[20];
 322        int status;
 323        pid_t pid;
 324
 325        get_remote_heads(fd[0], &ref, nr_match, match, 1);
 326        if (!ref) {
 327                packet_flush(fd[1]);
 328                die("no matching remote head");
 329        }
 330        if (everything_local(ref)) {
 331                packet_flush(fd[1]);
 332                goto all_done;
 333        }
 334        if (find_common(fd, sha1, ref) < 0)
 335                fprintf(stderr, "warning: no common commits\n");
 336        pid = fork();
 337        if (pid < 0)
 338                die("git-fetch-pack: unable to fork off git-unpack-objects");
 339        if (!pid) {
 340                dup2(fd[0], 0);
 341                close(fd[0]);
 342                close(fd[1]);
 343                execlp("git-unpack-objects", "git-unpack-objects",
 344                       quiet ? "-q" : NULL, NULL);
 345                die("git-unpack-objects exec failed");
 346        }
 347        close(fd[0]);
 348        close(fd[1]);
 349        while (waitpid(pid, &status, 0) < 0) {
 350                if (errno != EINTR)
 351                        die("waiting for git-unpack-objects: %s", strerror(errno));
 352        }
 353        if (WIFEXITED(status)) {
 354                int code = WEXITSTATUS(status);
 355                if (code)
 356                        die("git-unpack-objects died with error code %d", code);
 357all_done:
 358                while (ref) {
 359                        printf("%s %s\n",
 360                               sha1_to_hex(ref->old_sha1), ref->name);
 361                        ref = ref->next;
 362                }
 363                return 0;
 364        }
 365        if (WIFSIGNALED(status)) {
 366                int sig = WTERMSIG(status);
 367                die("git-unpack-objects died of signal %d", sig);
 368        }
 369        die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 370}
 371
 372int main(int argc, char **argv)
 373{
 374        int i, ret, nr_heads;
 375        char *dest = NULL, **heads;
 376        int fd[2];
 377        pid_t pid;
 378
 379        nr_heads = 0;
 380        heads = NULL;
 381        for (i = 1; i < argc; i++) {
 382                char *arg = argv[i];
 383
 384                if (*arg == '-') {
 385                        if (!strncmp("--exec=", arg, 7)) {
 386                                exec = arg + 7;
 387                                continue;
 388                        }
 389                        if (!strcmp("-q", arg)) {
 390                                quiet = 1;
 391                                continue;
 392                        }
 393                        if (!strcmp("-v", arg)) {
 394                                verbose = 1;
 395                                continue;
 396                        }
 397                        usage(fetch_pack_usage);
 398                }
 399                dest = arg;
 400                heads = argv + i + 1;
 401                nr_heads = argc - i - 1;
 402                break;
 403        }
 404        if (!dest)
 405                usage(fetch_pack_usage);
 406        pid = git_connect(fd, dest, exec);
 407        if (pid < 0)
 408                return 1;
 409        ret = fetch_pack(fd, nr_heads, heads);
 410        close(fd[0]);
 411        close(fd[1]);
 412        finish_connect(pid);
 413        return ret;
 414}