send-pack.con commit Refer to git-rev-parse:Specifying Revisions from git.txt (d47107d)
   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5#include "pkt-line.h"
   6#include "exec_cmd.h"
   7
   8static const char send_pack_usage[] =
   9"git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
  10"  --all and explicit <head> specification are mutually exclusive.";
  11static const char *exec = "git-receive-pack";
  12static int verbose;
  13static int send_all;
  14static int force_update;
  15static int use_thin_pack;
  16
  17static int is_zero_sha1(const unsigned char *sha1)
  18{
  19        int i;
  20
  21        for (i = 0; i < 20; i++) {
  22                if (*sha1++)
  23                        return 0;
  24        }
  25        return 1;
  26}
  27
  28static void exec_pack_objects(void)
  29{
  30        static const char *args[] = {
  31                "pack-objects",
  32                "--stdout",
  33                NULL
  34        };
  35        execv_git_cmd(args);
  36        die("git-pack-objects exec failed (%s)", strerror(errno));
  37}
  38
  39static void exec_rev_list(struct ref *refs)
  40{
  41        static const char *args[4];
  42        int i = 0;
  43
  44        args[i++] = "rev-list"; /* 0 */
  45        if (use_thin_pack)      /* 1 */
  46                args[i++] = "--objects-edge";
  47        else
  48                args[i++] = "--objects";
  49
  50        args[i++] = "--stdin";
  51
  52        args[i] = NULL;
  53        execv_git_cmd(args);
  54        die("git-rev-list exec failed (%s)", strerror(errno));
  55}
  56
  57/*
  58 * Run "rev-list --stdin | pack-objects" pipe.
  59 */
  60static void rev_list(int fd, struct ref *refs)
  61{
  62        int pipe_fd[2];
  63        pid_t pack_objects_pid;
  64
  65        if (pipe(pipe_fd) < 0)
  66                die("rev-list setup: pipe failed");
  67        pack_objects_pid = fork();
  68        if (!pack_objects_pid) {
  69                /* The child becomes pack-objects; reads from pipe
  70                 * and writes to the original fd
  71                 */
  72                dup2(pipe_fd[0], 0);
  73                dup2(fd, 1);
  74                close(pipe_fd[0]);
  75                close(pipe_fd[1]);
  76                close(fd);
  77                exec_pack_objects();
  78                die("pack-objects setup failed");
  79        }
  80        if (pack_objects_pid < 0)
  81                die("pack-objects fork failed");
  82
  83        /* We become rev-list --stdin; output goes to pipe. */
  84        dup2(pipe_fd[1], 1);
  85        close(pipe_fd[0]);
  86        close(pipe_fd[1]);
  87        close(fd);
  88        exec_rev_list(refs);
  89}
  90
  91/*
  92 * Create "rev-list --stdin | pack-objects" pipe and feed
  93 * the refs into the pipeline.
  94 */
  95static void rev_list_generate(int fd, struct ref *refs)
  96{
  97        int pipe_fd[2];
  98        pid_t rev_list_generate_pid;
  99
 100        if (pipe(pipe_fd) < 0)
 101                die("rev-list-generate setup: pipe failed");
 102        rev_list_generate_pid = fork();
 103        if (!rev_list_generate_pid) {
 104                /* The child becomes the "rev-list | pack-objects"
 105                 * pipeline.  It takes input from us, and its output
 106                 * goes to fd.
 107                 */
 108                dup2(pipe_fd[0], 0);
 109                dup2(fd, 1);
 110                close(pipe_fd[0]);
 111                close(pipe_fd[1]);
 112                close(fd);
 113                rev_list(fd, refs);
 114                die("rev-list setup failed");
 115        }
 116        if (rev_list_generate_pid < 0)
 117                die("rev-list-generate fork failed");
 118
 119        /* We feed the rev parameters to them.  We do not write into
 120         * fd nor read from the pipe.
 121         */
 122        close(pipe_fd[0]);
 123        close(fd);
 124        while (refs) {
 125                char buf[42];
 126
 127                if (!is_null_sha1(refs->old_sha1) &&
 128                    has_sha1_file(refs->old_sha1)) {
 129                        memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
 130                        buf[0] = '^';
 131                        buf[41] = '\n';
 132                        write(pipe_fd[1], buf, 42);
 133                }
 134                if (!is_null_sha1(refs->new_sha1)) {
 135                        memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
 136                        buf[40] = '\n';
 137                        write(pipe_fd[1], buf, 41);
 138                }
 139                refs = refs->next;
 140        }
 141        close(pipe_fd[1]);
 142        // waitpid(rev_list_generate_pid);
 143        exit(0);
 144}
 145
 146/*
 147 * Make a pack stream and spit it out into file descriptor fd
 148 */
 149static void pack_objects(int fd, struct ref *refs)
 150{
 151        pid_t rev_list_pid;
 152
 153        rev_list_pid = fork();
 154        if (!rev_list_pid) {
 155                rev_list_generate(fd, refs);
 156                die("rev-list setup failed");
 157        }
 158        if (rev_list_pid < 0)
 159                die("rev-list fork failed");
 160        /*
 161         * We don't wait for the rev-list pipeline in the parent:
 162         * we end up waiting for the other end instead
 163         */
 164}
 165
 166static void unmark_and_free(struct commit_list *list, unsigned int mark)
 167{
 168        while (list) {
 169                struct commit_list *temp = list;
 170                temp->item->object.flags &= ~mark;
 171                list = temp->next;
 172                free(temp);
 173        }
 174}
 175
 176static int ref_newer(const unsigned char *new_sha1,
 177                     const unsigned char *old_sha1)
 178{
 179        struct object *o;
 180        struct commit *old, *new;
 181        struct commit_list *list, *used;
 182        int found = 0;
 183
 184        /* Both new and old must be commit-ish and new is descendant of
 185         * old.  Otherwise we require --force.
 186         */
 187        o = deref_tag(parse_object(old_sha1), NULL, 0);
 188        if (!o || o->type != OBJ_COMMIT)
 189                return 0;
 190        old = (struct commit *) o;
 191
 192        o = deref_tag(parse_object(new_sha1), NULL, 0);
 193        if (!o || o->type != OBJ_COMMIT)
 194                return 0;
 195        new = (struct commit *) o;
 196
 197        if (parse_commit(new) < 0)
 198                return 0;
 199
 200        used = list = NULL;
 201        commit_list_insert(new, &list);
 202        while (list) {
 203                new = pop_most_recent_commit(&list, 1);
 204                commit_list_insert(new, &used);
 205                if (new == old) {
 206                        found = 1;
 207                        break;
 208                }
 209        }
 210        unmark_and_free(list, 1);
 211        unmark_and_free(used, 1);
 212        return found;
 213}
 214
 215static struct ref *local_refs, **local_tail;
 216static struct ref *remote_refs, **remote_tail;
 217
 218static int one_local_ref(const char *refname, const unsigned char *sha1)
 219{
 220        struct ref *ref;
 221        int len = strlen(refname) + 1;
 222        ref = xcalloc(1, sizeof(*ref) + len);
 223        hashcpy(ref->new_sha1, sha1);
 224        memcpy(ref->name, refname, len);
 225        *local_tail = ref;
 226        local_tail = &ref->next;
 227        return 0;
 228}
 229
 230static void get_local_heads(void)
 231{
 232        local_tail = &local_refs;
 233        for_each_ref(one_local_ref);
 234}
 235
 236static int receive_status(int in)
 237{
 238        char line[1000];
 239        int ret = 0;
 240        int len = packet_read_line(in, line, sizeof(line));
 241        if (len < 10 || memcmp(line, "unpack ", 7)) {
 242                fprintf(stderr, "did not receive status back\n");
 243                return -1;
 244        }
 245        if (memcmp(line, "unpack ok\n", 10)) {
 246                fputs(line, stderr);
 247                ret = -1;
 248        }
 249        while (1) {
 250                len = packet_read_line(in, line, sizeof(line));
 251                if (!len)
 252                        break;
 253                if (len < 3 ||
 254                    (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 255                        fprintf(stderr, "protocol error: %s\n", line);
 256                        ret = -1;
 257                        break;
 258                }
 259                if (!memcmp(line, "ok", 2))
 260                        continue;
 261                fputs(line, stderr);
 262                ret = -1;
 263        }
 264        return ret;
 265}
 266
 267static int send_pack(int in, int out, int nr_refspec, char **refspec)
 268{
 269        struct ref *ref;
 270        int new_refs;
 271        int ret = 0;
 272        int ask_for_status_report = 0;
 273        int expect_status_report = 0;
 274
 275        /* No funny business with the matcher */
 276        remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 277        get_local_heads();
 278
 279        /* Does the other end support the reporting? */
 280        if (server_supports("report-status"))
 281                ask_for_status_report = 1;
 282
 283        /* match them up */
 284        if (!remote_tail)
 285                remote_tail = &remote_refs;
 286        if (match_refs(local_refs, remote_refs, &remote_tail,
 287                       nr_refspec, refspec, send_all))
 288                return -1;
 289
 290        if (!remote_refs) {
 291                fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 292                return 0;
 293        }
 294
 295        /*
 296         * Finally, tell the other end!
 297         */
 298        new_refs = 0;
 299        for (ref = remote_refs; ref; ref = ref->next) {
 300                char old_hex[60], *new_hex;
 301                if (!ref->peer_ref)
 302                        continue;
 303                if (!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 304                        if (verbose)
 305                                fprintf(stderr, "'%s': up-to-date\n", ref->name);
 306                        continue;
 307                }
 308
 309                /* This part determines what can overwrite what.
 310                 * The rules are:
 311                 *
 312                 * (0) you can always use --force or +A:B notation to
 313                 *     selectively force individual ref pairs.
 314                 *
 315                 * (1) if the old thing does not exist, it is OK.
 316                 *
 317                 * (2) if you do not have the old thing, you are not allowed
 318                 *     to overwrite it; you would not know what you are losing
 319                 *     otherwise.
 320                 *
 321                 * (3) if both new and old are commit-ish, and new is a
 322                 *     descendant of old, it is OK.
 323                 */
 324
 325                if (!force_update &&
 326                    !is_zero_sha1(ref->old_sha1) &&
 327                    !ref->force) {
 328                        if (!has_sha1_file(ref->old_sha1) ||
 329                            !ref_newer(ref->peer_ref->new_sha1,
 330                                       ref->old_sha1)) {
 331                                /* We do not have the remote ref, or
 332                                 * we know that the remote ref is not
 333                                 * an ancestor of what we are trying to
 334                                 * push.  Either way this can be losing
 335                                 * commits at the remote end and likely
 336                                 * we were not up to date to begin with.
 337                                 */
 338                                error("remote '%s' is not a strict "
 339                                      "subset of local ref '%s'. "
 340                                      "maybe you are not up-to-date and "
 341                                      "need to pull first?",
 342                                      ref->name,
 343                                      ref->peer_ref->name);
 344                                ret = -2;
 345                                continue;
 346                        }
 347                }
 348                hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 349                if (is_zero_sha1(ref->new_sha1)) {
 350                        error("cannot happen anymore");
 351                        ret = -3;
 352                        continue;
 353                }
 354                new_refs++;
 355                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 356                new_hex = sha1_to_hex(ref->new_sha1);
 357
 358                if (ask_for_status_report) {
 359                        packet_write(out, "%s %s %s%c%s",
 360                                     old_hex, new_hex, ref->name, 0,
 361                                     "report-status");
 362                        ask_for_status_report = 0;
 363                        expect_status_report = 1;
 364                }
 365                else
 366                        packet_write(out, "%s %s %s",
 367                                     old_hex, new_hex, ref->name);
 368                fprintf(stderr, "updating '%s'", ref->name);
 369                if (strcmp(ref->name, ref->peer_ref->name))
 370                        fprintf(stderr, " using '%s'", ref->peer_ref->name);
 371                fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 372        }
 373
 374        packet_flush(out);
 375        if (new_refs)
 376                pack_objects(out, remote_refs);
 377        close(out);
 378
 379        if (expect_status_report) {
 380                if (receive_status(in))
 381                        ret = -4;
 382        }
 383
 384        if (!new_refs && ret == 0)
 385                fprintf(stderr, "Everything up-to-date\n");
 386        return ret;
 387}
 388
 389
 390int main(int argc, char **argv)
 391{
 392        int i, nr_heads = 0;
 393        char *dest = NULL;
 394        char **heads = NULL;
 395        int fd[2], ret;
 396        pid_t pid;
 397
 398        setup_git_directory();
 399        git_config(git_default_config);
 400
 401        argv++;
 402        for (i = 1; i < argc; i++, argv++) {
 403                char *arg = *argv;
 404
 405                if (*arg == '-') {
 406                        if (!strncmp(arg, "--exec=", 7)) {
 407                                exec = arg + 7;
 408                                continue;
 409                        }
 410                        if (!strcmp(arg, "--all")) {
 411                                send_all = 1;
 412                                continue;
 413                        }
 414                        if (!strcmp(arg, "--force")) {
 415                                force_update = 1;
 416                                continue;
 417                        }
 418                        if (!strcmp(arg, "--verbose")) {
 419                                verbose = 1;
 420                                continue;
 421                        }
 422                        if (!strcmp(arg, "--thin")) {
 423                                use_thin_pack = 1;
 424                                continue;
 425                        }
 426                        usage(send_pack_usage);
 427                }
 428                if (!dest) {
 429                        dest = arg;
 430                        continue;
 431                }
 432                heads = argv;
 433                nr_heads = argc - i;
 434                break;
 435        }
 436        if (!dest)
 437                usage(send_pack_usage);
 438        if (heads && send_all)
 439                usage(send_pack_usage);
 440        pid = git_connect(fd, dest, exec);
 441        if (pid < 0)
 442                return 1;
 443        ret = send_pack(fd[0], fd[1], nr_heads, heads);
 444        close(fd[0]);
 445        close(fd[1]);
 446        ret |= finish_connect(pid);
 447        return !!ret;
 448}