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();
  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 static void repo_set_commondir(struct repository *repo,
  95                                const char *commondir)
  96 {
  97         struct strbuf sb = STRBUF_INIT;
  98
  99         free(repo->commondir);
 100
 101         if (commondir) {
 102                 repo->different_commondir = 1;
 103                 repo->commondir = xstrdup(commondir);
 104                 return;
 105         }
 106
 107         repo->different_commondir = get_common_dir_noenv(&sb, repo->gitdir);
 108         repo->commondir = strbuf_detach(&sb, NULL);
 109 }
 110
 111 void repo_set_gitdir(struct repository *repo,
 112                      const char *root,
 113                      const struct set_gitdir_args *o)
 114 {
 115         const char *gitfile = read_gitfile(root);
 116         /*
 117          * repo->gitdir is saved because the caller could pass "root"
 118          * that also points to repo->gitdir. We want to keep it alive
 119          * until after xstrdup(root). Then we can free it.
 120          */
 121         char *old_gitdir = repo->gitdir;
 122
 123         repo->gitdir = xstrdup(gitfile ? gitfile : root);
 124         free(old_gitdir);
 125
 126         repo_set_commondir(repo, o->commondir);
 127
 128         if (!repo->objects->odb) {
 129                 CALLOC_ARRAY(repo->objects->odb, 1);
 130                 repo->objects->odb_tail = &repo->objects->odb->next;
 131         }
 132         expand_base_dir(&repo->objects->odb->path, o->object_dir,
 133                         repo->commondir, "objects");
 134
 135         repo->objects->odb->disable_ref_updates = o->disable_ref_updates;
 136
 137         free(repo->objects->alternate_db);
 138         repo->objects->alternate_db = xstrdup_or_null(o->alternate_db);
 139         expand_base_dir(&repo->graft_file, o->graft_file,
 140                         repo->commondir, "info/grafts");
 141         expand_base_dir(&repo->index_file, o->index_file,
 142                         repo->gitdir, "index");
 143 }
 144
 145 void repo_set_hash_algo(struct repository *repo, int hash_algo)
 146 {
 147         repo->hash_algo = &hash_algos[hash_algo];
 148 }
 149
 150 void repo_set_compat_hash_algo(struct repository *repo, int algo)
 151 {
 152         if (hash_algo_by_ptr(repo->hash_algo) == algo)
 153                 BUG("hash_algo and compat_hash_algo match");
 154         repo->compat_hash_algo = algo ? &hash_algos[algo] : NULL;
 155         if (repo->compat_hash_algo)
 156                 repo_read_loose_object_map(repo);
 157 }
 158
 159 void repo_set_ref_storage_format(struct repository *repo,
 160                                  enum ref_storage_format format)
 161 {
 162         repo->ref_storage_format = format;
 163 }
 164
 165 /*
 166  * Attempt to resolve and set the provided 'gitdir' for repository 'repo'.
 167  * Return 0 upon success and a non-zero value upon failure.
 168  */
 169 static int repo_init_gitdir(struct repository *repo, const char *gitdir)
 170 {
 171         int ret = 0;
 172         int error = 0;
 173         char *abspath = NULL;
 174         const char *resolved_gitdir;
 175         struct set_gitdir_args args = { NULL };
 176
 177         abspath = real_pathdup(gitdir, 0);
 178         if (!abspath) {
 179                 ret = -1;
 180                 goto out;
 181         }
 182
 183         /* 'gitdir' must reference the gitdir directly */
 184         resolved_gitdir = resolve_gitdir_gently(abspath, &error);
 185         if (!resolved_gitdir) {
 186                 ret = -1;
 187                 goto out;
 188         }
 189
 190         repo_set_gitdir(repo, resolved_gitdir, &args);
 191
 192 out:
 193         free(abspath);
 194         return ret;
 195 }
 196
 197 void repo_set_worktree(struct repository *repo, const char *path)
 198 {
 199         repo->worktree = real_pathdup(path, 1);
 200
 201         trace2_def_repo(repo);
 202 }
 203
 204 static int read_and_verify_repository_format(struct repository_format *format,
 205                                              const char *commondir)
 206 {
 207         int ret = 0;
 208         struct strbuf sb = STRBUF_INIT;
 209
 210         strbuf_addf(&sb, "%s/config", commondir);
 211         read_repository_format(format, sb.buf);
 212         strbuf_reset(&sb);
 213
 214         if (verify_repository_format(format, &sb) < 0) {
 215                 warning("%s", sb.buf);
 216                 ret = -1;
 217         }
 218
 219         strbuf_release(&sb);
 220         return ret;
 221 }
 222
 223 /*
 224  * Initialize 'repo' based on the provided 'gitdir'.
 225  * Return 0 upon success and a non-zero value upon failure.
 226  */
 227 int repo_init(struct repository *repo,
 228               const char *gitdir,
 229               const char *worktree)
 230 {
 231         struct repository_format format = REPOSITORY_FORMAT_INIT;
 232         memset(repo, 0, sizeof(*repo));
 233
 234         initialize_repository(repo);
 235
 236         if (repo_init_gitdir(repo, gitdir))
 237                 goto error;
 238
 239         if (read_and_verify_repository_format(&format, repo->commondir))
 240                 goto error;
 241
 242         repo_set_hash_algo(repo, format.hash_algo);
 243         repo_set_compat_hash_algo(repo, format.compat_hash_algo);
 244         repo_set_ref_storage_format(repo, format.ref_storage_format);
 245         repo->repository_format_worktree_config = format.worktree_config;
 246
 247         /* take ownership of format.partial_clone */
 248         repo->repository_format_partial_clone = format.partial_clone;
 249         format.partial_clone = NULL;
 250
 251         if (worktree)
 252                 repo_set_worktree(repo, worktree);
 253
 254         if (repo->compat_hash_algo)
 255                 repo_read_loose_object_map(repo);
 256
 257         clear_repository_format(&format);
 258         return 0;
 259
 260 error:
 261         repo_clear(repo);
 262         return -1;
 263 }
 264
 265 int repo_submodule_init(struct repository *subrepo,
 266                         struct repository *superproject,
 267                         const char *path,
 268                         const struct object_id *treeish_name)
 269 {
 270         struct strbuf gitdir = STRBUF_INIT;
 271         struct strbuf worktree = STRBUF_INIT;
 272         int ret = 0;
 273
 274         strbuf_repo_worktree_path(&gitdir, superproject, "%s/.git", path);
 275         strbuf_repo_worktree_path(&worktree, superproject, "%s", path);
 276
 277         if (repo_init(subrepo, gitdir.buf, worktree.buf)) {
 278                 /*
 279                  * If initialization fails then it may be due to the submodule
 280                  * not being populated in the superproject's worktree.  Instead
 281                  * we can try to initialize the submodule by finding it's gitdir
 282                  * in the superproject's 'modules' directory.  In this case the
 283                  * submodule would not have a worktree.
 284                  */
 285                 const struct submodule *sub =
 286                         submodule_from_path(superproject, treeish_name, path);
 287                 if (!sub) {
 288                         ret = -1;
 289                         goto out;
 290                 }
 291
 292                 strbuf_reset(&gitdir);
 293                 submodule_name_to_gitdir(&gitdir, superproject, sub->name);
 294
 295                 if (repo_init(subrepo, gitdir.buf, NULL)) {
 296                         ret = -1;
 297                         goto out;
 298                 }
 299         }
 300
 301         subrepo->submodule_prefix = xstrfmt("%s%s/",
 302                                             superproject->submodule_prefix ?
 303                                             superproject->submodule_prefix :
 304                                             "", path);
 305
 306 out:
 307         strbuf_release(&gitdir);
 308         strbuf_release(&worktree);
 309         return ret;
 310 }
 311
 312 static void repo_clear_path_cache(struct repo_path_cache *cache)
 313 {
 314         FREE_AND_NULL(cache->squash_msg);
 315         FREE_AND_NULL(cache->squash_msg);
 316         FREE_AND_NULL(cache->merge_msg);
 317         FREE_AND_NULL(cache->merge_rr);
 318         FREE_AND_NULL(cache->merge_mode);
 319         FREE_AND_NULL(cache->merge_head);
 320         FREE_AND_NULL(cache->fetch_head);
 321         FREE_AND_NULL(cache->shallow);
 322 }
 323
 324 void repo_clear(struct repository *repo)
 325 {
 326         struct hashmap_iter iter;
 327         struct strmap_entry *e;
 328
 329         FREE_AND_NULL(repo->gitdir);
 330         FREE_AND_NULL(repo->commondir);
 331         FREE_AND_NULL(repo->graft_file);
 332         FREE_AND_NULL(repo->index_file);
 333         FREE_AND_NULL(repo->worktree);
 334         FREE_AND_NULL(repo->submodule_prefix);
 335
 336         raw_object_store_clear(repo->objects);
 337         FREE_AND_NULL(repo->objects);
 338
 339         parsed_object_pool_clear(repo->parsed_objects);
 340         FREE_AND_NULL(repo->parsed_objects);
 341
 342         FREE_AND_NULL(repo->settings.fsmonitor);
 343
 344         if (repo->config) {
 345                 git_configset_clear(repo->config);
 346                 FREE_AND_NULL(repo->config);
 347         }
 348
 349         if (repo->submodule_cache) {
 350                 submodule_cache_free(repo->submodule_cache);
 351                 repo->submodule_cache = NULL;
 352         }
 353
 354         if (repo->index) {
 355                 discard_index(repo->index);
 356                 FREE_AND_NULL(repo->index);
 357         }
 358
 359         if (repo->promisor_remote_config) {
 360                 promisor_remote_clear(repo->promisor_remote_config);
 361                 FREE_AND_NULL(repo->promisor_remote_config);
 362         }
 363
 364         if (repo->remote_state) {
 365                 remote_state_clear(repo->remote_state);
 366                 FREE_AND_NULL(repo->remote_state);
 367         }
 368
 369         strmap_for_each_entry(&repo->submodule_ref_stores, &iter, e)
 370                 ref_store_release(e->value);
 371         strmap_clear(&repo->submodule_ref_stores, 1);
 372
 373         strmap_for_each_entry(&repo->worktree_ref_stores, &iter, e)
 374                 ref_store_release(e->value);
 375         strmap_clear(&repo->worktree_ref_stores, 1);
 376
 377         repo_clear_path_cache(&repo->cached_paths);
 378 }
 379
 380 int repo_read_index(struct repository *repo)
 381 {
 382         int res;
 383
 384         /* Complete the double-reference */
 385         if (!repo->index) {
 386                 ALLOC_ARRAY(repo->index, 1);
 387                 index_state_init(repo->index, repo);
 388         } else if (repo->index->repo != repo) {
 389                 BUG("repo's index should point back at itself");
 390         }
 391
 392         res = read_index_from(repo->index, repo->index_file, repo->gitdir);
 393
 394         prepare_repo_settings(repo);
 395         if (repo->settings.command_requires_full_index)
 396                 ensure_full_index(repo->index);
 397
 398         /*
 399          * If sparse checkouts are in use, check whether paths with the
 400          * SKIP_WORKTREE attribute are missing from the worktree; if not,
 401          * clear that attribute for that path.
 402          */
 403         clear_skip_worktree_from_present_files(repo->index);
 404
 405         return res;
 406 }
 407
 408 int repo_hold_locked_index(struct repository *repo,
 409                            struct lock_file *lf,
 410                            int flags)
 411 {
 412         if (!repo->index_file)
 413                 BUG("the repo hasn't been setup");
 414         return hold_lock_file_for_update(lf, repo->index_file, flags);
 415 }