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