repository.c

   1 #include "git-compat-util.h"
   2 #include "abspath.h"
   3 #include "repository.h"
   4 #include "object-store-ll.h"
   5 #include "config.h"
   6 #include "object.h"
   7 #include "lockfile.h"
   8 #include "path.h"
   9 #include "read-cache-ll.h"
  10 #include "remote.h"
  11 #include "setup.h"
  12 #include "loose.h"
  13 #include "submodule-config.h"
  14 #include "sparse-index.h"
  15 #include "trace2.h"
  16 #include "promisor-remote.h"
  17 #include "refs.h"
  18
  19 /*
  20  * We do not define `USE_THE_REPOSITORY_VARIABLE` in this file because we do
  21  * not want to rely on functions that implicitly use `the_repository`. This
  22  * means that the `extern` declaration of `the_repository` isn't visible here,
  23  * which makes sparse unhappy. We thus declare it here.
  24  */
  25 extern struct repository *the_repository;
  26
  27 /* The main repository */
  28 static struct repository the_repo;
  29 struct repository *the_repository = &the_repo;
  30
  31 /*
  32  * An escape hatch: if we hit a bug in the production code that fails
  33  * to set an appropriate hash algorithm (most likely to happen when
  34  * running outside a repository), we can tell the user who reported
  35  * the crash to set the environment variable to "sha1" (all lowercase)
  36  * to revert to the historical behaviour of defaulting to SHA-1.
  37  */
  38 static void set_default_hash_algo(struct repository *repo)
  39 {
  40         const char *hash_name;
  41         int algo;
  42
  43         hash_name = getenv("GIT_TEST_DEFAULT_HASH_ALGO");
  44         if (!hash_name)
  45                 return;
  46         algo = hash_algo_by_name(hash_name);
  47         if (algo == GIT_HASH_UNKNOWN)
  48                 return;
  49
  50         repo_set_hash_algo(repo, algo);
  51 }
  52
  53 void initialize_repository(struct repository *repo)
  54 {
  55         repo->objects = raw_object_store_new();
  56         repo->remote_state = remote_state_new();
  57         repo->parsed_objects = parsed_object_pool_new(repo);
  58         ALLOC_ARRAY(repo->index, 1);
  59         index_state_init(repo->index, repo);
  60
  61         /*
  62          * When a command runs inside a repository, it learns what
  63          * hash algorithm is in use from the repository, but some
  64          * commands are designed to work outside a repository, yet
  65          * they want to access the_hash_algo, if only for the length
  66          * of the hashed value to see if their input looks like a
  67          * plausible hash value.
  68          *
  69          * We are in the process of identifying such code paths and
  70          * giving them an appropriate default individually; any
  71          * unconverted code paths that try to access the_hash_algo
  72          * will thus fail.  The end-users however have an escape hatch
  73          * to set GIT_TEST_DEFAULT_HASH_ALGO environment variable to
  74          * "sha1" to get back the old behaviour of defaulting to SHA-1.
  75          *
  76          * This escape hatch is deliberately kept unadvertised, so
  77          * that they see crashes and we can get a report before
  78          * telling them about it.
  79          */
  80         if (repo == the_repository)
  81                 set_default_hash_algo(repo);
  82 }
  83
  84 static void expand_base_dir(char **out, const char *in,
  85                             const char *base_dir, const char *def_in)
  86 {
  87         free(*out);
  88         if (in)
  89                 *out = xstrdup(in);
  90         else
  91                 *out = xstrfmt("%s/%s", base_dir, def_in);
  92 }
  93
  94 const char *repo_get_git_dir(struct repository *repo)
  95 {
  96         if (!repo->gitdir)
  97                 BUG("repository hasn't been set up");
  98         return repo->gitdir;
  99 }
 100
 101 const char *repo_get_common_dir(struct repository *repo)
 102 {
 103         if (!repo->commondir)
 104                 BUG("repository hasn't been set up");
 105         return repo->commondir;
 106 }
 107
 108 const char *repo_get_object_directory(struct repository *repo)
 109 {
 110         if (!repo->objects->odb)
 111                 BUG("repository hasn't been set up");
 112         return repo->objects->odb->path;
 113 }
 114
 115 const char *repo_get_index_file(struct repository *repo)
 116 {
 117         if (!repo->index_file)
 118                 BUG("repository hasn't been set up");
 119         return repo->index_file;
 120 }
 121
 122 const char *repo_get_graft_file(struct repository *repo)
 123 {
 124         if (!repo->graft_file)
 125                 BUG("repository hasn't been set up");
 126         return repo->graft_file;
 127 }
 128
 129 const char *repo_get_work_tree(struct repository *repo)
 130 {
 131         return repo->worktree;
 132 }
 133
 134 static void repo_set_commondir(struct repository *repo,
 135                                const char *commondir)
 136 {
 137         struct strbuf sb = STRBUF_INIT;
 138
 139         free(repo->commondir);
 140
 141         if (commondir) {
 142                 repo->different_commondir = 1;
 143                 repo->commondir = xstrdup(commondir);
 144                 return;
 145         }
 146
 147         repo->different_commondir = get_common_dir_noenv(&sb, repo->gitdir);
 148         repo->commondir = strbuf_detach(&sb, NULL);
 149 }
 150
 151 void repo_set_gitdir(struct repository *repo,
 152                      const char *root,
 153                      const struct set_gitdir_args *o)
 154 {
 155         const char *gitfile = read_gitfile(root);
 156         /*
 157          * repo->gitdir is saved because the caller could pass "root"
 158          * that also points to repo->gitdir. We want to keep it alive
 159          * until after xstrdup(root). Then we can free it.
 160          */
 161         char *old_gitdir = repo->gitdir;
 162
 163         repo->gitdir = xstrdup(gitfile ? gitfile : root);
 164         free(old_gitdir);
 165
 166         repo_set_commondir(repo, o->commondir);
 167
 168         if (!repo->objects->odb) {
 169                 CALLOC_ARRAY(repo->objects->odb, 1);
 170                 repo->objects->odb_tail = &repo->objects->odb->next;
 171         }
 172         expand_base_dir(&repo->objects->odb->path, o->object_dir,
 173                         repo->commondir, "objects");
 174
 175         repo->objects->odb->disable_ref_updates = o->disable_ref_updates;
 176
 177         free(repo->objects->alternate_db);
 178         repo->objects->alternate_db = xstrdup_or_null(o->alternate_db);
 179         expand_base_dir(&repo->graft_file, o->graft_file,
 180                         repo->commondir, "info/grafts");
 181         expand_base_dir(&repo->index_file, o->index_file,
 182                         repo->gitdir, "index");
 183 }
 184
 185 void repo_set_hash_algo(struct repository *repo, int hash_algo)
 186 {
 187         repo->hash_algo = &hash_algos[hash_algo];
 188 }
 189
 190 void repo_set_compat_hash_algo(struct repository *repo, int algo)
 191 {
 192         if (hash_algo_by_ptr(repo->hash_algo) == algo)
 193                 BUG("hash_algo and compat_hash_algo match");
 194         repo->compat_hash_algo = algo ? &hash_algos[algo] : NULL;
 195         if (repo->compat_hash_algo)
 196                 repo_read_loose_object_map(repo);
 197 }
 198
 199 void repo_set_ref_storage_format(struct repository *repo,
 200                                  enum ref_storage_format format)
 201 {
 202         repo->ref_storage_format = format;
 203 }
 204
 205 /*
 206  * Attempt to resolve and set the provided 'gitdir' for repository 'repo'.
 207  * Return 0 upon success and a non-zero value upon failure.
 208  */
 209 static int repo_init_gitdir(struct repository *repo, const char *gitdir)
 210 {
 211         int ret = 0;
 212         int error = 0;
 213         char *abspath = NULL;
 214         const char *resolved_gitdir;
 215         struct set_gitdir_args args = { NULL };
 216
 217         abspath = real_pathdup(gitdir, 0);
 218         if (!abspath) {
 219                 ret = -1;
 220                 goto out;
 221         }
 222
 223         /* 'gitdir' must reference the gitdir directly */
 224         resolved_gitdir = resolve_gitdir_gently(abspath, &error);
 225         if (!resolved_gitdir) {
 226                 ret = -1;
 227                 goto out;
 228         }
 229
 230         repo_set_gitdir(repo, resolved_gitdir, &args);
 231
 232 out:
 233         free(abspath);
 234         return ret;
 235 }
 236
 237 void repo_set_worktree(struct repository *repo, const char *path)
 238 {
 239         repo->worktree = real_pathdup(path, 1);
 240
 241         trace2_def_repo(repo);
 242 }
 243
 244 static int read_and_verify_repository_format(struct repository_format *format,
 245                                              const char *commondir)
 246 {
 247         int ret = 0;
 248         struct strbuf sb = STRBUF_INIT;
 249
 250         strbuf_addf(&sb, "%s/config", commondir);
 251         read_repository_format(format, sb.buf);
 252         strbuf_reset(&sb);
 253
 254         if (verify_repository_format(format, &sb) < 0) {
 255                 warning("%s", sb.buf);
 256                 ret = -1;
 257         }
 258
 259         strbuf_release(&sb);
 260         return ret;
 261 }
 262
 263 /*
 264  * Initialize 'repo' based on the provided 'gitdir'.
 265  * Return 0 upon success and a non-zero value upon failure.
 266  */
 267 int repo_init(struct repository *repo,
 268               const char *gitdir,
 269               const char *worktree)
 270 {
 271         struct repository_format format = REPOSITORY_FORMAT_INIT;
 272         memset(repo, 0, sizeof(*repo));
 273
 274         initialize_repository(repo);
 275
 276         if (repo_init_gitdir(repo, gitdir))
 277                 goto error;
 278
 279         if (read_and_verify_repository_format(&format, repo->commondir))
 280                 goto error;
 281
 282         repo_set_hash_algo(repo, format.hash_algo);
 283         repo_set_compat_hash_algo(repo, format.compat_hash_algo);
 284         repo_set_ref_storage_format(repo, format.ref_storage_format);
 285         repo->repository_format_worktree_config = format.worktree_config;
 286
 287         /* take ownership of format.partial_clone */
 288         repo->repository_format_partial_clone = format.partial_clone;
 289         format.partial_clone = NULL;
 290
 291         if (worktree)
 292                 repo_set_worktree(repo, worktree);
 293
 294         if (repo->compat_hash_algo)
 295                 repo_read_loose_object_map(repo);
 296
 297         clear_repository_format(&format);
 298         return 0;
 299
 300 error:
 301         repo_clear(repo);
 302         return -1;
 303 }
 304
 305 int repo_submodule_init(struct repository *subrepo,
 306                         struct repository *superproject,
 307                         const char *path,
 308                         const struct object_id *treeish_name)
 309 {
 310         struct strbuf gitdir = STRBUF_INIT;
 311         struct strbuf worktree = STRBUF_INIT;
 312         int ret = 0;
 313
 314         strbuf_repo_worktree_path(&gitdir, superproject, "%s/.git", path);
 315         strbuf_repo_worktree_path(&worktree, superproject, "%s", path);
 316
 317         if (repo_init(subrepo, gitdir.buf, worktree.buf)) {
 318                 /*
 319                  * If initialization fails then it may be due to the submodule
 320                  * not being populated in the superproject's worktree.  Instead
 321                  * we can try to initialize the submodule by finding it's gitdir
 322                  * in the superproject's 'modules' directory.  In this case the
 323                  * submodule would not have a worktree.
 324                  */
 325                 const struct submodule *sub =
 326                         submodule_from_path(superproject, treeish_name, path);
 327                 if (!sub) {
 328                         ret = -1;
 329                         goto out;
 330                 }
 331
 332                 strbuf_reset(&gitdir);
 333                 submodule_name_to_gitdir(&gitdir, superproject, sub->name);
 334
 335                 if (repo_init(subrepo, gitdir.buf, NULL)) {
 336                         ret = -1;
 337                         goto out;
 338                 }
 339         }
 340
 341         subrepo->submodule_prefix = xstrfmt("%s%s/",
 342                                             superproject->submodule_prefix ?
 343                                             superproject->submodule_prefix :
 344                                             "", path);
 345
 346 out:
 347         strbuf_release(&gitdir);
 348         strbuf_release(&worktree);
 349         return ret;
 350 }
 351
 352 static void repo_clear_path_cache(struct repo_path_cache *cache)
 353 {
 354         FREE_AND_NULL(cache->squash_msg);
 355         FREE_AND_NULL(cache->squash_msg);
 356         FREE_AND_NULL(cache->merge_msg);
 357         FREE_AND_NULL(cache->merge_rr);
 358         FREE_AND_NULL(cache->merge_mode);
 359         FREE_AND_NULL(cache->merge_head);
 360         FREE_AND_NULL(cache->fetch_head);
 361         FREE_AND_NULL(cache->shallow);
 362 }
 363
 364 void repo_clear(struct repository *repo)
 365 {
 366         struct hashmap_iter iter;
 367         struct strmap_entry *e;
 368
 369         FREE_AND_NULL(repo->gitdir);
 370         FREE_AND_NULL(repo->commondir);
 371         FREE_AND_NULL(repo->graft_file);
 372         FREE_AND_NULL(repo->index_file);
 373         FREE_AND_NULL(repo->worktree);
 374         FREE_AND_NULL(repo->submodule_prefix);
 375
 376         raw_object_store_clear(repo->objects);
 377         FREE_AND_NULL(repo->objects);
 378
 379         parsed_object_pool_clear(repo->parsed_objects);
 380         FREE_AND_NULL(repo->parsed_objects);
 381
 382         FREE_AND_NULL(repo->settings.fsmonitor);
 383
 384         if (repo->config) {
 385                 git_configset_clear(repo->config);
 386                 FREE_AND_NULL(repo->config);
 387         }
 388
 389         if (repo->submodule_cache) {
 390                 submodule_cache_free(repo->submodule_cache);
 391                 repo->submodule_cache = NULL;
 392         }
 393
 394         if (repo->index) {
 395                 discard_index(repo->index);
 396                 FREE_AND_NULL(repo->index);
 397         }
 398
 399         if (repo->promisor_remote_config) {
 400                 promisor_remote_clear(repo->promisor_remote_config);
 401                 FREE_AND_NULL(repo->promisor_remote_config);
 402         }
 403
 404         if (repo->remote_state) {
 405                 remote_state_clear(repo->remote_state);
 406                 FREE_AND_NULL(repo->remote_state);
 407         }
 408
 409         strmap_for_each_entry(&repo->submodule_ref_stores, &iter, e)
 410                 ref_store_release(e->value);
 411         strmap_clear(&repo->submodule_ref_stores, 1);
 412
 413         strmap_for_each_entry(&repo->worktree_ref_stores, &iter, e)
 414                 ref_store_release(e->value);
 415         strmap_clear(&repo->worktree_ref_stores, 1);
 416
 417         repo_clear_path_cache(&repo->cached_paths);
 418 }
 419
 420 int repo_read_index(struct repository *repo)
 421 {
 422         int res;
 423
 424         /* Complete the double-reference */
 425         if (!repo->index) {
 426                 ALLOC_ARRAY(repo->index, 1);
 427                 index_state_init(repo->index, repo);
 428         } else if (repo->index->repo != repo) {
 429                 BUG("repo's index should point back at itself");
 430         }
 431
 432         res = read_index_from(repo->index, repo->index_file, repo->gitdir);
 433
 434         prepare_repo_settings(repo);
 435         if (repo->settings.command_requires_full_index)
 436                 ensure_full_index(repo->index);
 437
 438         /*
 439          * If sparse checkouts are in use, check whether paths with the
 440          * SKIP_WORKTREE attribute are missing from the worktree; if not,
 441          * clear that attribute for that path.
 442          */
 443         clear_skip_worktree_from_present_files(repo->index);
 444
 445         return res;
 446 }
 447
 448 int repo_hold_locked_index(struct repository *repo,
 449                            struct lock_file *lf,
 450                            int flags)
 451 {
 452         if (!repo->index_file)
 453                 BUG("the repo hasn't been setup");
 454         return hold_lock_file_for_update(lf, repo->index_file, flags);
 455 }