send-pack.con commit git-commit: allow --only to lose what was staged earlier. (158d057)
   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                "--all-progress",
  33                "--stdout",
  34                NULL
  35        };
  36        execv_git_cmd(args);
  37        die("git-pack-objects exec failed (%s)", strerror(errno));
  38}
  39
  40static void exec_rev_list(struct ref *refs)
  41{
  42        static const char *args[4];
  43        int i = 0;
  44
  45        args[i++] = "rev-list"; /* 0 */
  46        if (use_thin_pack)      /* 1 */
  47                args[i++] = "--objects-edge";
  48        else
  49                args[i++] = "--objects";
  50
  51        args[i++] = "--stdin";
  52
  53        args[i] = NULL;
  54        execv_git_cmd(args);
  55        die("git-rev-list exec failed (%s)", strerror(errno));
  56}
  57
  58/*
  59 * Run "rev-list --stdin | pack-objects" pipe.
  60 */
  61static void rev_list(int fd, struct ref *refs)
  62{
  63        int pipe_fd[2];
  64        pid_t pack_objects_pid;
  65
  66        if (pipe(pipe_fd) < 0)
  67                die("rev-list setup: pipe failed");
  68        pack_objects_pid = fork();
  69        if (!pack_objects_pid) {
  70                /* The child becomes pack-objects; reads from pipe
  71                 * and writes to the original fd
  72                 */
  73                dup2(pipe_fd[0], 0);
  74                dup2(fd, 1);
  75                close(pipe_fd[0]);
  76                close(pipe_fd[1]);
  77                close(fd);
  78                exec_pack_objects();
  79                die("pack-objects setup failed");
  80        }
  81        if (pack_objects_pid < 0)
  82                die("pack-objects fork failed");
  83
  84        /* We become rev-list --stdin; output goes to pipe. */
  85        dup2(pipe_fd[1], 1);
  86        close(pipe_fd[0]);
  87        close(pipe_fd[1]);
  88        close(fd);
  89        exec_rev_list(refs);
  90}
  91
  92/*
  93 * Create "rev-list --stdin | pack-objects" pipe and feed
  94 * the refs into the pipeline.
  95 */
  96static void rev_list_generate(int fd, struct ref *refs)
  97{
  98        int pipe_fd[2];
  99        pid_t rev_list_generate_pid;
 100
 101        if (pipe(pipe_fd) < 0)
 102                die("rev-list-generate setup: pipe failed");
 103        rev_list_generate_pid = fork();
 104        if (!rev_list_generate_pid) {
 105                /* The child becomes the "rev-list | pack-objects"
 106                 * pipeline.  It takes input from us, and its output
 107                 * goes to fd.
 108                 */
 109                dup2(pipe_fd[0], 0);
 110                dup2(fd, 1);
 111                close(pipe_fd[0]);
 112                close(pipe_fd[1]);
 113                close(fd);
 114                rev_list(fd, refs);
 115                die("rev-list setup failed");
 116        }
 117        if (rev_list_generate_pid < 0)
 118                die("rev-list-generate fork failed");
 119
 120        /* We feed the rev parameters to them.  We do not write into
 121         * fd nor read from the pipe.
 122         */
 123        close(pipe_fd[0]);
 124        close(fd);
 125        while (refs) {
 126                char buf[42];
 127
 128                if (!is_null_sha1(refs->old_sha1) &&
 129                    has_sha1_file(refs->old_sha1)) {
 130                        memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
 131                        buf[0] = '^';
 132                        buf[41] = '\n';
 133                        write(pipe_fd[1], buf, 42);
 134                }
 135                if (!is_null_sha1(refs->new_sha1)) {
 136                        memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
 137                        buf[40] = '\n';
 138                        write(pipe_fd[1], buf, 41);
 139                }
 140                refs = refs->next;
 141        }
 142        close(pipe_fd[1]);
 143        // waitpid(rev_list_generate_pid);
 144        exit(0);
 145}
 146
 147/*
 148 * Make a pack stream and spit it out into file descriptor fd
 149 */
 150static void pack_objects(int fd, struct ref *refs)
 151{
 152        pid_t rev_list_pid;
 153
 154        rev_list_pid = fork();
 155        if (!rev_list_pid) {
 156                rev_list_generate(fd, refs);
 157                die("rev-list setup failed");
 158        }
 159        if (rev_list_pid < 0)
 160                die("rev-list fork failed");
 161        /*
 162         * We don't wait for the rev-list pipeline in the parent:
 163         * we end up waiting for the other end instead
 164         */
 165}
 166
 167static void unmark_and_free(struct commit_list *list, unsigned int mark)
 168{
 169        while (list) {
 170                struct commit_list *temp = list;
 171                temp->item->object.flags &= ~mark;
 172                list = temp->next;
 173                free(temp);
 174        }
 175}
 176
 177static int ref_newer(const unsigned char *new_sha1,
 178                     const unsigned char *old_sha1)
 179{
 180        struct object *o;
 181        struct commit *old, *new;
 182        struct commit_list *list, *used;
 183        int found = 0;
 184
 185        /* Both new and old must be commit-ish and new is descendant of
 186         * old.  Otherwise we require --force.
 187         */
 188        o = deref_tag(parse_object(old_sha1), NULL, 0);
 189        if (!o || o->type != OBJ_COMMIT)
 190                return 0;
 191        old = (struct commit *) o;
 192
 193        o = deref_tag(parse_object(new_sha1), NULL, 0);
 194        if (!o || o->type != OBJ_COMMIT)
 195                return 0;
 196        new = (struct commit *) o;
 197
 198        if (parse_commit(new) < 0)
 199                return 0;
 200
 201        used = list = NULL;
 202        commit_list_insert(new, &list);
 203        while (list) {
 204                new = pop_most_recent_commit(&list, 1);
 205                commit_list_insert(new, &used);
 206                if (new == old) {
 207                        found = 1;
 208                        break;
 209                }
 210        }
 211        unmark_and_free(list, 1);
 212        unmark_and_free(used, 1);
 213        return found;
 214}
 215
 216static struct ref *local_refs, **local_tail;
 217static struct ref *remote_refs, **remote_tail;
 218
 219static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 220{
 221        struct ref *ref;
 222        int len = strlen(refname) + 1;
 223        ref = xcalloc(1, sizeof(*ref) + len);
 224        hashcpy(ref->new_sha1, sha1);
 225        memcpy(ref->name, refname, len);
 226        *local_tail = ref;
 227        local_tail = &ref->next;
 228        return 0;
 229}
 230
 231static void get_local_heads(void)
 232{
 233        local_tail = &local_refs;
 234        for_each_ref(one_local_ref, NULL);
 235}
 236
 237static int receive_status(int in)
 238{
 239        char line[1000];
 240        int ret = 0;
 241        int len = packet_read_line(in, line, sizeof(line));
 242        if (len < 10 || memcmp(line, "unpack ", 7)) {
 243                fprintf(stderr, "did not receive status back\n");
 244                return -1;
 245        }
 246        if (memcmp(line, "unpack ok\n", 10)) {
 247                fputs(line, stderr);
 248                ret = -1;
 249        }
 250        while (1) {
 251                len = packet_read_line(in, line, sizeof(line));
 252                if (!len)
 253                        break;
 254                if (len < 3 ||
 255                    (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 256                        fprintf(stderr, "protocol error: %s\n", line);
 257                        ret = -1;
 258                        break;
 259                }
 260                if (!memcmp(line, "ok", 2))
 261                        continue;
 262                fputs(line, stderr);
 263                ret = -1;
 264        }
 265        return ret;
 266}
 267
 268static int send_pack(int in, int out, int nr_refspec, char **refspec)
 269{
 270        struct ref *ref;
 271        int new_refs;
 272        int ret = 0;
 273        int ask_for_status_report = 0;
 274        int allow_deleting_refs = 0;
 275        int expect_status_report = 0;
 276
 277        /* No funny business with the matcher */
 278        remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 279        get_local_heads();
 280
 281        /* Does the other end support the reporting? */
 282        if (server_supports("report-status"))
 283                ask_for_status_report = 1;
 284        if (server_supports("delete-refs"))
 285                allow_deleting_refs = 1;
 286
 287        /* match them up */
 288        if (!remote_tail)
 289                remote_tail = &remote_refs;
 290        if (match_refs(local_refs, remote_refs, &remote_tail,
 291                       nr_refspec, refspec, send_all))
 292                return -1;
 293
 294        if (!remote_refs) {
 295                fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 296                return 0;
 297        }
 298
 299        /*
 300         * Finally, tell the other end!
 301         */
 302        new_refs = 0;
 303        for (ref = remote_refs; ref; ref = ref->next) {
 304                char old_hex[60], *new_hex;
 305                int delete_ref;
 306
 307                if (!ref->peer_ref)
 308                        continue;
 309
 310                delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
 311                if (delete_ref && !allow_deleting_refs) {
 312                        error("remote does not support deleting refs");
 313                        ret = -2;
 314                        continue;
 315                }
 316                if (!delete_ref &&
 317                    !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 318                        if (verbose)
 319                                fprintf(stderr, "'%s': up-to-date\n", ref->name);
 320                        continue;
 321                }
 322
 323                /* This part determines what can overwrite what.
 324                 * The rules are:
 325                 *
 326                 * (0) you can always use --force or +A:B notation to
 327                 *     selectively force individual ref pairs.
 328                 *
 329                 * (1) if the old thing does not exist, it is OK.
 330                 *
 331                 * (2) if you do not have the old thing, you are not allowed
 332                 *     to overwrite it; you would not know what you are losing
 333                 *     otherwise.
 334                 *
 335                 * (3) if both new and old are commit-ish, and new is a
 336                 *     descendant of old, it is OK.
 337                 *
 338                 * (4) regardless of all of the above, removing :B is
 339                 *     always allowed.
 340                 */
 341
 342                if (!force_update &&
 343                    !delete_ref &&
 344                    !is_zero_sha1(ref->old_sha1) &&
 345                    !ref->force) {
 346                        if (!has_sha1_file(ref->old_sha1) ||
 347                            !ref_newer(ref->peer_ref->new_sha1,
 348                                       ref->old_sha1)) {
 349                                /* We do not have the remote ref, or
 350                                 * we know that the remote ref is not
 351                                 * an ancestor of what we are trying to
 352                                 * push.  Either way this can be losing
 353                                 * commits at the remote end and likely
 354                                 * we were not up to date to begin with.
 355                                 */
 356                                error("remote '%s' is not a strict "
 357                                      "subset of local ref '%s'. "
 358                                      "maybe you are not up-to-date and "
 359                                      "need to pull first?",
 360                                      ref->name,
 361                                      ref->peer_ref->name);
 362                                ret = -2;
 363                                continue;
 364                        }
 365                }
 366                hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 367                if (!delete_ref)
 368                        new_refs++;
 369                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 370                new_hex = sha1_to_hex(ref->new_sha1);
 371
 372                if (ask_for_status_report) {
 373                        packet_write(out, "%s %s %s%c%s",
 374                                     old_hex, new_hex, ref->name, 0,
 375                                     "report-status");
 376                        ask_for_status_report = 0;
 377                        expect_status_report = 1;
 378                }
 379                else
 380                        packet_write(out, "%s %s %s",
 381                                     old_hex, new_hex, ref->name);
 382                if (delete_ref)
 383                        fprintf(stderr, "deleting '%s'\n", ref->name);
 384                else {
 385                        fprintf(stderr, "updating '%s'", ref->name);
 386                        if (strcmp(ref->name, ref->peer_ref->name))
 387                                fprintf(stderr, " using '%s'",
 388                                        ref->peer_ref->name);
 389                        fprintf(stderr, "\n  from %s\n  to   %s\n",
 390                                old_hex, new_hex);
 391                }
 392        }
 393
 394        packet_flush(out);
 395        if (new_refs)
 396                pack_objects(out, remote_refs);
 397        close(out);
 398
 399        if (expect_status_report) {
 400                if (receive_status(in))
 401                        ret = -4;
 402        }
 403
 404        if (!new_refs && ret == 0)
 405                fprintf(stderr, "Everything up-to-date\n");
 406        return ret;
 407}
 408
 409
 410int main(int argc, char **argv)
 411{
 412        int i, nr_heads = 0;
 413        char *dest = NULL;
 414        char **heads = NULL;
 415        int fd[2], ret;
 416        pid_t pid;
 417
 418        setup_git_directory();
 419        git_config(git_default_config);
 420
 421        argv++;
 422        for (i = 1; i < argc; i++, argv++) {
 423                char *arg = *argv;
 424
 425                if (*arg == '-') {
 426                        if (!strncmp(arg, "--exec=", 7)) {
 427                                exec = arg + 7;
 428                                continue;
 429                        }
 430                        if (!strcmp(arg, "--all")) {
 431                                send_all = 1;
 432                                continue;
 433                        }
 434                        if (!strcmp(arg, "--force")) {
 435                                force_update = 1;
 436                                continue;
 437                        }
 438                        if (!strcmp(arg, "--verbose")) {
 439                                verbose = 1;
 440                                continue;
 441                        }
 442                        if (!strcmp(arg, "--thin")) {
 443                                use_thin_pack = 1;
 444                                continue;
 445                        }
 446                        usage(send_pack_usage);
 447                }
 448                if (!dest) {
 449                        dest = arg;
 450                        continue;
 451                }
 452                heads = argv;
 453                nr_heads = argc - i;
 454                break;
 455        }
 456        if (!dest)
 457                usage(send_pack_usage);
 458        if (heads && send_all)
 459                usage(send_pack_usage);
 460        pid = git_connect(fd, dest, exec);
 461        if (pid < 0)
 462                return 1;
 463        ret = send_pack(fd[0], fd[1], nr_heads, heads);
 464        close(fd[0]);
 465        close(fd[1]);
 466        ret |= finish_connect(pid);
 467        return !!ret;
 468}