src/clone.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include "clone.h"
   9
  10 #include "git2/clone.h"
  11 #include "git2/remote.h"
  12 #include "git2/revparse.h"
  13 #include "git2/branch.h"
  14 #include "git2/config.h"
  15 #include "git2/checkout.h"
  16 #include "git2/commit.h"
  17 #include "git2/tree.h"
  18
  19 #include "remote.h"
  20 #include "futils.h"
  21 #include "refs.h"
  22 #include "fs_path.h"
  23 #include "repository.h"
  24 #include "odb.h"
  25
  26 static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link);
  27
  28 static int create_branch(
  29         git_reference **branch,
  30         git_repository *repo,
  31         const git_oid *target,
  32         const char *name,
  33         const char *log_message)
  34 {
  35         git_commit *head_obj = NULL;
  36         git_reference *branch_ref = NULL;
  37         git_str refname = GIT_STR_INIT;
  38         int error;
  39
  40         /* Find the target commit */
  41         if ((error = git_commit_lookup(&head_obj, repo, target)) < 0)
  42                 return error;
  43
  44         /* Create the new branch */
  45         if ((error = git_str_printf(&refname, GIT_REFS_HEADS_DIR "%s", name)) < 0)
  46                 return error;
  47
  48         error = git_reference_create(&branch_ref, repo, git_str_cstr(&refname), target, 0, log_message);
  49         git_str_dispose(&refname);
  50         git_commit_free(head_obj);
  51
  52         if (!error)
  53                 *branch = branch_ref;
  54         else
  55                 git_reference_free(branch_ref);
  56
  57         return error;
  58 }
  59
  60 static int setup_tracking_config(
  61         git_repository *repo,
  62         const char *branch_name,
  63         const char *remote_name,
  64         const char *merge_target)
  65 {
  66         git_config *cfg;
  67         git_str remote_key = GIT_STR_INIT, merge_key = GIT_STR_INIT;
  68         int error = -1;
  69
  70         if (git_repository_config__weakptr(&cfg, repo) < 0)
  71                 return -1;
  72
  73         if (git_str_printf(&remote_key, "branch.%s.remote", branch_name) < 0)
  74                 goto cleanup;
  75
  76         if (git_str_printf(&merge_key, "branch.%s.merge", branch_name) < 0)
  77                 goto cleanup;
  78
  79         if (git_config_set_string(cfg, git_str_cstr(&remote_key), remote_name) < 0)
  80                 goto cleanup;
  81
  82         if (git_config_set_string(cfg, git_str_cstr(&merge_key), merge_target) < 0)
  83                 goto cleanup;
  84
  85         error = 0;
  86
  87 cleanup:
  88         git_str_dispose(&remote_key);
  89         git_str_dispose(&merge_key);
  90         return error;
  91 }
  92
  93 static int create_tracking_branch(
  94         git_reference **branch,
  95         git_repository *repo,
  96         const git_oid *target,
  97         const char *branch_name,
  98         const char *log_message)
  99 {
 100         int error;
 101
 102         if ((error = create_branch(branch, repo, target, branch_name, log_message)) < 0)
 103                 return error;
 104
 105         return setup_tracking_config(
 106                 repo,
 107                 branch_name,
 108                 GIT_REMOTE_ORIGIN,
 109                 git_reference_name(*branch));
 110 }
 111
 112 static int update_head_to_new_branch(
 113         git_repository *repo,
 114         const git_oid *target,
 115         const char *name,
 116         const char *reflog_message)
 117 {
 118         git_reference *tracking_branch = NULL;
 119         int error;
 120
 121         if (!git__prefixcmp(name, GIT_REFS_HEADS_DIR))
 122                 name += strlen(GIT_REFS_HEADS_DIR);
 123
 124         error = create_tracking_branch(&tracking_branch, repo, target, name,
 125                         reflog_message);
 126
 127         if (!error)
 128                 error = git_repository_set_head(
 129                         repo, git_reference_name(tracking_branch));
 130
 131         git_reference_free(tracking_branch);
 132
 133         /* if it already existed, then the user's refspec created it for us, ignore it' */
 134         if (error == GIT_EEXISTS)
 135                 error = 0;
 136
 137         return error;
 138 }
 139
 140 static int update_head_to_default(git_repository *repo)
 141 {
 142         git_str initialbranch = GIT_STR_INIT;
 143         const char *branch_name;
 144         int error = 0;
 145
 146         if ((error = git_repository_initialbranch(&initialbranch, repo)) < 0)
 147                 goto done;
 148
 149         if (git__prefixcmp(initialbranch.ptr, GIT_REFS_HEADS_DIR) != 0) {
 150                 git_error_set(GIT_ERROR_INVALID, "invalid initial branch '%s'", initialbranch.ptr);
 151                 error = -1;
 152                 goto done;
 153         }
 154
 155         branch_name = initialbranch.ptr + strlen(GIT_REFS_HEADS_DIR);
 156
 157         error = setup_tracking_config(repo, branch_name, GIT_REMOTE_ORIGIN,
 158                 initialbranch.ptr);
 159
 160 done:
 161         git_str_dispose(&initialbranch);
 162         return error;
 163 }
 164
 165 static int update_remote_head(
 166         git_repository *repo,
 167         git_remote *remote,
 168         git_str *target,
 169         const char *reflog_message)
 170 {
 171         git_refspec *refspec;
 172         git_reference *remote_head = NULL;
 173         git_str remote_head_name = GIT_STR_INIT;
 174         git_str remote_branch_name = GIT_STR_INIT;
 175         int error;
 176
 177         /* Determine the remote tracking ref name from the local branch */
 178         refspec = git_remote__matching_refspec(remote, git_str_cstr(target));
 179
 180         if (refspec == NULL) {
 181                 git_error_set(GIT_ERROR_NET, "the remote's default branch does not fit the refspec configuration");
 182                 error = GIT_EINVALIDSPEC;
 183                 goto cleanup;
 184         }
 185
 186         if ((error = git_refspec__transform(
 187                 &remote_branch_name,
 188                 refspec,
 189                 git_str_cstr(target))) < 0)
 190                 goto cleanup;
 191
 192         if ((error = git_str_printf(&remote_head_name,
 193                 "%s%s/%s",
 194                 GIT_REFS_REMOTES_DIR,
 195                 git_remote_name(remote),
 196                 GIT_HEAD_FILE)) < 0)
 197                 goto cleanup;
 198
 199         error = git_reference_symbolic_create(
 200                 &remote_head,
 201                 repo,
 202                 git_str_cstr(&remote_head_name),
 203                 git_str_cstr(&remote_branch_name),
 204                 true,
 205                 reflog_message);
 206
 207 cleanup:
 208         git_reference_free(remote_head);
 209         git_str_dispose(&remote_branch_name);
 210         git_str_dispose(&remote_head_name);
 211         return error;
 212 }
 213
 214 static int update_head_to_remote(
 215                 git_repository *repo,
 216                 git_remote *remote,
 217                 const char *reflog_message)
 218 {
 219         int error = 0;
 220         size_t refs_len;
 221         const git_remote_head *remote_head, **refs;
 222         const git_oid *remote_head_id;
 223         git_str branch = GIT_STR_INIT;
 224
 225         if ((error = git_remote_ls(&refs, &refs_len, remote)) < 0)
 226                 return error;
 227
 228         /* We cloned an empty repository or one with an unborn HEAD */
 229         if (refs_len == 0 || strcmp(refs[0]->name, GIT_HEAD_FILE))
 230                 return update_head_to_default(repo);
 231
 232         /* We know we have HEAD, let's see where it points */
 233         remote_head = refs[0];
 234         GIT_ASSERT(remote_head);
 235
 236         remote_head_id = &remote_head->oid;
 237
 238         error = git_remote__default_branch(&branch, remote);
 239         if (error == GIT_ENOTFOUND) {
 240                 error = git_repository_set_head_detached(
 241                         repo, remote_head_id);
 242                 goto cleanup;
 243         }
 244
 245         if ((error = update_remote_head(repo, remote, &branch, reflog_message)) < 0)
 246                 goto cleanup;
 247
 248         error = update_head_to_new_branch(
 249                 repo,
 250                 remote_head_id,
 251                 git_str_cstr(&branch),
 252                 reflog_message);
 253
 254 cleanup:
 255         git_str_dispose(&branch);
 256
 257         return error;
 258 }
 259
 260 static int update_head_to_branch(
 261                 git_repository *repo,
 262                 git_remote *remote,
 263                 const char *branch,
 264                 const char *reflog_message)
 265 {
 266         int retcode;
 267         git_str remote_branch_name = GIT_STR_INIT;
 268         git_reference *remote_ref = NULL;
 269         git_str default_branch = GIT_STR_INIT;
 270
 271         GIT_ASSERT_ARG(remote);
 272         GIT_ASSERT_ARG(branch);
 273
 274         if ((retcode = git_str_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",
 275                 git_remote_name(remote), branch)) < 0 )
 276                 goto cleanup;
 277
 278         if ((retcode = git_reference_lookup(&remote_ref, repo, git_str_cstr(&remote_branch_name))) < 0)
 279                 goto cleanup;
 280
 281         if ((retcode = update_head_to_new_branch(repo, git_reference_target(remote_ref), branch,
 282                         reflog_message)) < 0)
 283                 goto cleanup;
 284
 285         if ((retcode = git_remote__default_branch(&default_branch, remote)) < 0)
 286                 goto cleanup;
 287
 288         if (!git_remote__matching_refspec(remote, git_str_cstr(&default_branch)))
 289                 goto cleanup;
 290
 291         retcode = update_remote_head(repo, remote, &default_branch, reflog_message);
 292
 293 cleanup:
 294         git_reference_free(remote_ref);
 295         git_str_dispose(&remote_branch_name);
 296         git_str_dispose(&default_branch);
 297         return retcode;
 298 }
 299
 300 static int default_repository_create(git_repository **out, const char *path, int bare, void *payload)
 301 {
 302         GIT_UNUSED(payload);
 303
 304         return git_repository_init(out, path, bare);
 305 }
 306
 307 static int default_remote_create(
 308                 git_remote **out,
 309                 git_repository *repo,
 310                 const char *name,
 311                 const char *url,
 312                 void *payload)
 313 {
 314         GIT_UNUSED(payload);
 315
 316         return git_remote_create(out, repo, name, url);
 317 }
 318
 319 /*
 320  * submodules?
 321  */
 322
 323 static int create_and_configure_origin(
 324                 git_remote **out,
 325                 git_repository *repo,
 326                 const char *url,
 327                 const git_clone_options *options)
 328 {
 329         int error;
 330         git_remote *origin = NULL;
 331         char buf[GIT_PATH_MAX];
 332         git_remote_create_cb remote_create = options->remote_cb;
 333         void *payload = options->remote_cb_payload;
 334
 335         /* If the path exists and is a dir, the url should be the absolute path */
 336         if (git_fs_path_root(url) < 0 && git_fs_path_exists(url) && git_fs_path_isdir(url)) {
 337                 if (p_realpath(url, buf) == NULL)
 338                         return -1;
 339
 340                 url = buf;
 341         }
 342
 343         if (!remote_create) {
 344                 remote_create = default_remote_create;
 345                 payload = NULL;
 346         }
 347
 348         if ((error = remote_create(&origin, repo, "origin", url, payload)) < 0)
 349                 goto on_error;
 350
 351         *out = origin;
 352         return 0;
 353
 354 on_error:
 355         git_remote_free(origin);
 356         return error;
 357 }
 358
 359 static bool should_checkout(
 360         git_repository *repo,
 361         bool is_bare,
 362         const git_checkout_options *opts)
 363 {
 364         if (is_bare)
 365                 return false;
 366
 367         if (!opts)
 368                 return false;
 369
 370         if (opts->checkout_strategy == GIT_CHECKOUT_NONE)
 371                 return false;
 372
 373         return !git_repository_head_unborn(repo);
 374 }
 375
 376 static int checkout_branch(git_repository *repo, git_remote *remote, const git_checkout_options *co_opts, const char *branch, const char *reflog_message)
 377 {
 378         int error;
 379
 380         if (branch)
 381                 error = update_head_to_branch(repo, remote, branch, reflog_message);
 382         /* Point HEAD to the same ref as the remote's head */
 383         else
 384                 error = update_head_to_remote(repo, remote, reflog_message);
 385
 386         if (!error && should_checkout(repo, git_repository_is_bare(repo), co_opts))
 387                 error = git_checkout_head(repo, co_opts);
 388
 389         return error;
 390 }
 391
 392 static int clone_into(git_repository *repo, git_remote *_remote, const git_fetch_options *opts, const git_checkout_options *co_opts, const char *branch)
 393 {
 394         int error;
 395         git_str reflog_message = GIT_STR_INIT;
 396         git_fetch_options fetch_opts;
 397         git_remote *remote;
 398
 399         GIT_ASSERT_ARG(repo);
 400         GIT_ASSERT_ARG(_remote);
 401
 402         if (!git_repository_is_empty(repo)) {
 403                 git_error_set(GIT_ERROR_INVALID, "the repository is not empty");
 404                 return -1;
 405         }
 406
 407         if ((error = git_remote_dup(&remote, _remote)) < 0)
 408                 return error;
 409
 410         memcpy(&fetch_opts, opts, sizeof(git_fetch_options));
 411         fetch_opts.update_fetchhead = 0;
 412         fetch_opts.download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;
 413         git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
 414
 415         if ((error = git_remote_fetch(remote, NULL, &fetch_opts, git_str_cstr(&reflog_message))) != 0)
 416                 goto cleanup;
 417
 418         error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));
 419
 420 cleanup:
 421         git_remote_free(remote);
 422         git_str_dispose(&reflog_message);
 423
 424         return error;
 425 }
 426
 427 int git_clone__should_clone_local(const char *url_or_path, git_clone_local_t local)
 428 {
 429         git_str fromurl = GIT_STR_INIT;
 430         const char *path = url_or_path;
 431         bool is_url, is_local;
 432
 433         if (local == GIT_CLONE_NO_LOCAL)
 434                 return 0;
 435
 436         if ((is_url = git_fs_path_is_local_file_url(url_or_path)) != 0) {
 437                 if (git_fs_path_fromurl(&fromurl, url_or_path) < 0) {
 438                         is_local = -1;
 439                         goto done;
 440                 }
 441
 442                 path = fromurl.ptr;
 443         }
 444
 445         is_local = (!is_url || local != GIT_CLONE_LOCAL_AUTO) &&
 446                 git_fs_path_isdir(path);
 447
 448 done:
 449         git_str_dispose(&fromurl);
 450         return is_local;
 451 }
 452
 453 static int git__clone(
 454         git_repository **out,
 455         const char *url,
 456         const char *local_path,
 457         const git_clone_options *_options,
 458         int use_existing)
 459 {
 460         int error = 0;
 461         git_repository *repo = NULL;
 462         git_remote *origin;
 463         git_clone_options options = GIT_CLONE_OPTIONS_INIT;
 464         uint32_t rmdir_flags = GIT_RMDIR_REMOVE_FILES;
 465         git_repository_create_cb repository_cb;
 466
 467         GIT_ASSERT_ARG(out);
 468         GIT_ASSERT_ARG(url);
 469         GIT_ASSERT_ARG(local_path);
 470
 471         if (_options)
 472                 memcpy(&options, _options, sizeof(git_clone_options));
 473
 474         GIT_ERROR_CHECK_VERSION(&options, GIT_CLONE_OPTIONS_VERSION, "git_clone_options");
 475
 476         /* Only clone to a new directory or an empty directory */
 477         if (git_fs_path_exists(local_path) && !use_existing && !git_fs_path_is_empty_dir(local_path)) {
 478                 git_error_set(GIT_ERROR_INVALID,
 479                         "'%s' exists and is not an empty directory", local_path);
 480                 return GIT_EEXISTS;
 481         }
 482
 483         /* Only remove the root directory on failure if we create it */
 484         if (git_fs_path_exists(local_path))
 485                 rmdir_flags |= GIT_RMDIR_SKIP_ROOT;
 486
 487         if (options.repository_cb)
 488                 repository_cb = options.repository_cb;
 489         else
 490                 repository_cb = default_repository_create;
 491
 492         if ((error = repository_cb(&repo, local_path, options.bare, options.repository_cb_payload)) < 0)
 493                 return error;
 494
 495         if (!(error = create_and_configure_origin(&origin, repo, url, &options))) {
 496                 int clone_local = git_clone__should_clone_local(url, options.local);
 497                 int link = options.local != GIT_CLONE_LOCAL_NO_LINKS;
 498
 499                 if (clone_local == 1)
 500                         error = clone_local_into(
 501                                 repo, origin, &options.fetch_opts, &options.checkout_opts,
 502                                 options.checkout_branch, link);
 503                 else if (clone_local == 0)
 504                         error = clone_into(
 505                                 repo, origin, &options.fetch_opts, &options.checkout_opts,
 506                                 options.checkout_branch);
 507                 else
 508                         error = -1;
 509
 510                 git_remote_free(origin);
 511         }
 512
 513         if (error != 0) {
 514                 git_error_state last_error = {0};
 515                 git_error_state_capture(&last_error, error);
 516
 517                 git_repository_free(repo);
 518                 repo = NULL;
 519
 520                 (void)git_futils_rmdir_r(local_path, NULL, rmdir_flags);
 521
 522                 git_error_state_restore(&last_error);
 523         }
 524
 525         *out = repo;
 526         return error;
 527 }
 528
 529 int git_clone(
 530         git_repository **out,
 531         const char *url,
 532         const char *local_path,
 533         const git_clone_options *_options)
 534 {
 535         return git__clone(out, url, local_path, _options, 0);
 536 }
 537
 538 int git_clone__submodule(
 539         git_repository **out,
 540         const char *url,
 541         const char *local_path,
 542         const git_clone_options *_options)
 543 {
 544         return git__clone(out, url, local_path, _options, 1);
 545 }
 546
 547 int git_clone_options_init(git_clone_options *opts, unsigned int version)
 548 {
 549         GIT_INIT_STRUCTURE_FROM_TEMPLATE(
 550                 opts, version, git_clone_options, GIT_CLONE_OPTIONS_INIT);
 551         return 0;
 552 }
 553
 554 #ifndef GIT_DEPRECATE_HARD
 555 int git_clone_init_options(git_clone_options *opts, unsigned int version)
 556 {
 557         return git_clone_options_init(opts, version);
 558 }
 559 #endif
 560
 561 static bool can_link(const char *src, const char *dst, int link)
 562 {
 563 #ifdef GIT_WIN32
 564         GIT_UNUSED(src);
 565         GIT_UNUSED(dst);
 566         GIT_UNUSED(link);
 567         return false;
 568 #else
 569
 570         struct stat st_src, st_dst;
 571
 572         if (!link)
 573                 return false;
 574
 575         if (p_stat(src, &st_src) < 0)
 576                 return false;
 577
 578         if (p_stat(dst, &st_dst) < 0)
 579                 return false;
 580
 581         return st_src.st_dev == st_dst.st_dev;
 582 #endif
 583 }
 584
 585 static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link)
 586 {
 587         int error, flags;
 588         git_repository *src;
 589         git_str src_odb = GIT_STR_INIT, dst_odb = GIT_STR_INIT, src_path = GIT_STR_INIT;
 590         git_str reflog_message = GIT_STR_INIT;
 591
 592         GIT_ASSERT_ARG(repo);
 593         GIT_ASSERT_ARG(remote);
 594
 595         if (!git_repository_is_empty(repo)) {
 596                 git_error_set(GIT_ERROR_INVALID, "the repository is not empty");
 597                 return -1;
 598         }
 599
 600         /*
 601          * Let's figure out what path we should use for the source
 602          * repo, if it's not rooted, the path should be relative to
 603          * the repository's worktree/gitdir.
 604          */
 605         if ((error = git_fs_path_from_url_or_path(&src_path, git_remote_url(remote))) < 0)
 606                 return error;
 607
 608         /* Copy .git/objects/ from the source to the target */
 609         if ((error = git_repository_open(&src, git_str_cstr(&src_path))) < 0) {
 610                 git_str_dispose(&src_path);
 611                 return error;
 612         }
 613
 614         if (git_repository__item_path(&src_odb, src, GIT_REPOSITORY_ITEM_OBJECTS) < 0 ||
 615             git_repository__item_path(&dst_odb, repo, GIT_REPOSITORY_ITEM_OBJECTS) < 0) {
 616                 error = -1;
 617                 goto cleanup;
 618         }
 619
 620         flags = 0;
 621         if (can_link(git_repository_path(src), git_repository_path(repo), link))
 622                 flags |= GIT_CPDIR_LINK_FILES;
 623
 624         error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),
 625                                 flags, GIT_OBJECT_DIR_MODE);
 626
 627         /*
 628          * can_link() doesn't catch all variations, so if we hit an
 629          * error and did want to link, let's try again without trying
 630          * to link.
 631          */
 632         if (error < 0 && link) {
 633                 flags &= ~GIT_CPDIR_LINK_FILES;
 634                 error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),
 635                                         flags, GIT_OBJECT_DIR_MODE);
 636         }
 637
 638         if (error < 0)
 639                 goto cleanup;
 640
 641         git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
 642
 643         if ((error = git_remote_fetch(remote, NULL, fetch_opts, git_str_cstr(&reflog_message))) != 0)
 644                 goto cleanup;
 645
 646         error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));
 647
 648 cleanup:
 649         git_str_dispose(&reflog_message);
 650         git_str_dispose(&src_path);
 651         git_str_dispose(&src_odb);
 652         git_str_dispose(&dst_odb);
 653         git_repository_free(src);
 654         return error;
 655 }