1 files changed, 458 insertions, 0 deletions
diff --git a/repository.c b/repository.c
new file mode 100644
index 0000000000..ecd691181f
--- /dev/null
+++ b/repository.c
@@ -0,0 +1,458 @@
+#include "git-compat-util.h"
+#include "abspath.h"
+#include "repository.h"
+#include "odb.h"
+#include "config.h"
+#include "object.h"
+#include "lockfile.h"
+#include "path.h"
+#include "read-cache-ll.h"
+#include "remote.h"
+#include "setup.h"
+#include "loose.h"
+#include "submodule-config.h"
+#include "sparse-index.h"
+#include "trace2.h"
+#include "promisor-remote.h"
+#include "refs.h"
+
+/*
+ * We do not define `USE_THE_REPOSITORY_VARIABLE` in this file because we do
+ * not want to rely on functions that implicitly use `the_repository`. This
+ * means that the `extern` declaration of `the_repository` isn't visible here,
+ * which makes sparse unhappy. We thus declare it here.
+ */
+extern struct repository *the_repository;
+
+/* The main repository */
+static struct repository the_repo;
+struct repository *the_repository = &the_repo;
+
+/*
+ * An escape hatch: if we hit a bug in the production code that fails
+ * to set an appropriate hash algorithm (most likely to happen when
+ * running outside a repository), we can tell the user who reported
+ * the crash to set the environment variable to "sha1" (all lowercase)
+ * to revert to the historical behaviour of defaulting to SHA-1.
+ */
+static void set_default_hash_algo(struct repository *repo)
+{
+	const char *hash_name;
+	int algo;
+
+	hash_name = getenv("GIT_TEST_DEFAULT_HASH_ALGO");
+	if (!hash_name)
+		return;
+	algo = hash_algo_by_name(hash_name);
+	if (algo == GIT_HASH_UNKNOWN)
+		return;
+
+	repo_set_hash_algo(repo, algo);
+}
+
+void initialize_repository(struct repository *repo)
+{
+	repo->objects = odb_new(repo);
+	repo->remote_state = remote_state_new();
+	repo->parsed_objects = parsed_object_pool_new(repo);
+	ALLOC_ARRAY(repo->index, 1);
+	index_state_init(repo->index, repo);
+
+	/*
+	 * When a command runs inside a repository, it learns what
+	 * hash algorithm is in use from the repository, but some
+	 * commands are designed to work outside a repository, yet
+	 * they want to access the_hash_algo, if only for the length
+	 * of the hashed value to see if their input looks like a
+	 * plausible hash value.
+	 *
+	 * We are in the process of identifying such code paths and
+	 * giving them an appropriate default individually; any
+	 * unconverted code paths that try to access the_hash_algo
+	 * will thus fail.  The end-users however have an escape hatch
+	 * to set GIT_TEST_DEFAULT_HASH_ALGO environment variable to
+	 * "sha1" to get back the old behaviour of defaulting to SHA-1.
+	 *
+	 * This escape hatch is deliberately kept unadvertised, so
+	 * that they see crashes and we can get a report before
+	 * telling them about it.
+	 */
+	if (repo == the_repository)
+		set_default_hash_algo(repo);
+}
+
+static void expand_base_dir(char **out, const char *in,
+			    const char *base_dir, const char *def_in)
+{
+	free(*out);
+	if (in)
+		*out = xstrdup(in);
+	else
+		*out = xstrfmt("%s/%s", base_dir, def_in);
+}
+
+const char *repo_get_git_dir(struct repository *repo)
+{
+	if (!repo->gitdir)
+		BUG("repository hasn't been set up");
+	return repo->gitdir;
+}
+
+const char *repo_get_common_dir(struct repository *repo)
+{
+	if (!repo->commondir)
+		BUG("repository hasn't been set up");
+	return repo->commondir;
+}
+
+const char *repo_get_object_directory(struct repository *repo)
+{
+	if (!repo->objects->sources)
+		BUG("repository hasn't been set up");
+	return repo->objects->sources->path;
+}
+
+const char *repo_get_index_file(struct repository *repo)
+{
+	if (!repo->index_file)
+		BUG("repository hasn't been set up");
+	return repo->index_file;
+}
+
+const char *repo_get_graft_file(struct repository *repo)
+{
+	if (!repo->graft_file)
+		BUG("repository hasn't been set up");
+	return repo->graft_file;
+}
+
+const char *repo_get_work_tree(struct repository *repo)
+{
+	return repo->worktree;
+}
+
+static void repo_set_commondir(struct repository *repo,
+			       const char *commondir)
+{
+	struct strbuf sb = STRBUF_INIT;
+
+	free(repo->commondir);
+
+	if (commondir) {
+		repo->different_commondir = 1;
+		repo->commondir = xstrdup(commondir);
+		return;
+	}
+
+	repo->different_commondir = get_common_dir_noenv(&sb, repo->gitdir);
+	repo->commondir = strbuf_detach(&sb, NULL);
+}
+
+void repo_set_gitdir(struct repository *repo,
+		     const char *root,
+		     const struct set_gitdir_args *o)
+{
+	const char *gitfile = read_gitfile(root);
+	/*
+	 * repo->gitdir is saved because the caller could pass "root"
+	 * that also points to repo->gitdir. We want to keep it alive
+	 * until after xstrdup(root). Then we can free it.
+	 */
+	char *old_gitdir = repo->gitdir;
+
+	repo->gitdir = xstrdup(gitfile ? gitfile : root);
+	free(old_gitdir);
+
+	repo_set_commondir(repo, o->commondir);
+
+	if (!repo->objects->sources) {
+		CALLOC_ARRAY(repo->objects->sources, 1);
+		repo->objects->sources->odb = repo->objects;
+		repo->objects->sources_tail = &repo->objects->sources->next;
+	}
+	expand_base_dir(&repo->objects->sources->path, o->object_dir,
+			repo->commondir, "objects");
+
+	repo->objects->sources->disable_ref_updates = o->disable_ref_updates;
+
+	free(repo->objects->alternate_db);
+	repo->objects->alternate_db = xstrdup_or_null(o->alternate_db);
+	expand_base_dir(&repo->graft_file, o->graft_file,
+			repo->commondir, "info/grafts");
+	expand_base_dir(&repo->index_file, o->index_file,
+			repo->gitdir, "index");
+}
+
+void repo_set_hash_algo(struct repository *repo, int hash_algo)
+{
+	repo->hash_algo = &hash_algos[hash_algo];
+}
+
+void repo_set_compat_hash_algo(struct repository *repo, int algo)
+{
+	if (hash_algo_by_ptr(repo->hash_algo) == algo)
+		BUG("hash_algo and compat_hash_algo match");
+	repo->compat_hash_algo = algo ? &hash_algos[algo] : NULL;
+	if (repo->compat_hash_algo)
+		repo_read_loose_object_map(repo);
+}
+
+void repo_set_ref_storage_format(struct repository *repo,
+				 enum ref_storage_format format)
+{
+	repo->ref_storage_format = format;
+}
+
+/*
+ * Attempt to resolve and set the provided 'gitdir' for repository 'repo'.
+ * Return 0 upon success and a non-zero value upon failure.
+ */
+static int repo_init_gitdir(struct repository *repo, const char *gitdir)
+{
+	int ret = 0;
+	int error = 0;
+	char *abspath = NULL;
+	const char *resolved_gitdir;
+	struct set_gitdir_args args = { NULL };
+
+	abspath = real_pathdup(gitdir, 0);
+	if (!abspath) {
+		ret = -1;
+		goto out;
+	}
+
+	/* 'gitdir' must reference the gitdir directly */
+	resolved_gitdir = resolve_gitdir_gently(abspath, &error);
+	if (!resolved_gitdir) {
+		ret = -1;
+		goto out;
+	}
+
+	repo_set_gitdir(repo, resolved_gitdir, &args);
+
+out:
+	free(abspath);
+	return ret;
+}
+
+void repo_set_worktree(struct repository *repo, const char *path)
+{
+	repo->worktree = real_pathdup(path, 1);
+
+	trace2_def_repo(repo);
+}
+
+static int read_and_verify_repository_format(struct repository_format *format,
+					     const char *commondir)
+{
+	int ret = 0;
+	struct strbuf sb = STRBUF_INIT;
+
+	strbuf_addf(&sb, "%s/config", commondir);
+	read_repository_format(format, sb.buf);
+	strbuf_reset(&sb);
+
+	if (verify_repository_format(format, &sb) < 0) {
+		warning("%s", sb.buf);
+		ret = -1;
+	}
+
+	strbuf_release(&sb);
+	return ret;
+}
+
+/*
+ * Initialize 'repo' based on the provided 'gitdir'.
+ * Return 0 upon success and a non-zero value upon failure.
+ */
+int repo_init(struct repository *repo,
+	      const char *gitdir,
+	      const char *worktree)
+{
+	struct repository_format format = REPOSITORY_FORMAT_INIT;
+	memset(repo, 0, sizeof(*repo));
+
+	initialize_repository(repo);
+
+	if (repo_init_gitdir(repo, gitdir))
+		goto error;
+
+	if (read_and_verify_repository_format(&format, repo->commondir))
+		goto error;
+
+	repo_set_hash_algo(repo, format.hash_algo);
+	repo_set_compat_hash_algo(repo, format.compat_hash_algo);
+	repo_set_ref_storage_format(repo, format.ref_storage_format);
+	repo->repository_format_worktree_config = format.worktree_config;
+	repo->repository_format_relative_worktrees = format.relative_worktrees;
+	repo->repository_format_precious_objects = format.precious_objects;
+
+	/* take ownership of format.partial_clone */
+	repo->repository_format_partial_clone = format.partial_clone;
+	format.partial_clone = NULL;
+
+	if (worktree)
+		repo_set_worktree(repo, worktree);
+
+	if (repo->compat_hash_algo)
+		repo_read_loose_object_map(repo);
+
+	clear_repository_format(&format);
+	return 0;
+
+error:
+	repo_clear(repo);
+	return -1;
+}
+
+int repo_submodule_init(struct repository *subrepo,
+			struct repository *superproject,
+			const char *path,
+			const struct object_id *treeish_name)
+{
+	struct strbuf gitdir = STRBUF_INIT;
+	struct strbuf worktree = STRBUF_INIT;
+	int ret = 0;
+
+	repo_worktree_path_append(superproject, &gitdir, "%s/.git", path);
+	repo_worktree_path_append(superproject, &worktree, "%s", path);
+
+	if (repo_init(subrepo, gitdir.buf, worktree.buf)) {
+		/*
+		 * If initialization fails then it may be due to the submodule
+		 * not being populated in the superproject's worktree.  Instead
+		 * we can try to initialize the submodule by finding it's gitdir
+		 * in the superproject's 'modules' directory.  In this case the
+		 * submodule would not have a worktree.
+		 */
+		const struct submodule *sub =
+			submodule_from_path(superproject, treeish_name, path);
+		if (!sub) {
+			ret = -1;
+			goto out;
+		}
+
+		strbuf_reset(&gitdir);
+		submodule_name_to_gitdir(&gitdir, superproject, sub->name);
+
+		if (repo_init(subrepo, gitdir.buf, NULL)) {
+			ret = -1;
+			goto out;
+		}
+	}
+
+	subrepo->submodule_prefix = xstrfmt("%s%s/",
+					    superproject->submodule_prefix ?
+					    superproject->submodule_prefix :
+					    "", path);
+
+out:
+	strbuf_release(&gitdir);
+	strbuf_release(&worktree);
+	return ret;
+}
+
+static void repo_clear_path_cache(struct repo_path_cache *cache)
+{
+	FREE_AND_NULL(cache->squash_msg);
+	FREE_AND_NULL(cache->squash_msg);
+	FREE_AND_NULL(cache->merge_msg);
+	FREE_AND_NULL(cache->merge_rr);
+	FREE_AND_NULL(cache->merge_mode);
+	FREE_AND_NULL(cache->merge_head);
+	FREE_AND_NULL(cache->fetch_head);
+	FREE_AND_NULL(cache->shallow);
+}
+
+void repo_clear(struct repository *repo)
+{
+	struct hashmap_iter iter;
+	struct strmap_entry *e;
+
+	FREE_AND_NULL(repo->gitdir);
+	FREE_AND_NULL(repo->commondir);
+	FREE_AND_NULL(repo->graft_file);
+	FREE_AND_NULL(repo->index_file);
+	FREE_AND_NULL(repo->worktree);
+	FREE_AND_NULL(repo->submodule_prefix);
+
+	odb_clear(repo->objects);
+	FREE_AND_NULL(repo->objects);
+
+	parsed_object_pool_clear(repo->parsed_objects);
+	FREE_AND_NULL(repo->parsed_objects);
+
+	repo_settings_clear(repo);
+
+	if (repo->config) {
+		git_configset_clear(repo->config);
+		FREE_AND_NULL(repo->config);
+	}
+
+	if (repo->submodule_cache) {
+		submodule_cache_free(repo->submodule_cache);
+		repo->submodule_cache = NULL;
+	}
+
+	if (repo->index) {
+		discard_index(repo->index);
+		FREE_AND_NULL(repo->index);
+	}
+
+	if (repo->promisor_remote_config) {
+		promisor_remote_clear(repo->promisor_remote_config);
+		FREE_AND_NULL(repo->promisor_remote_config);
+	}
+
+	if (repo->remote_state) {
+		remote_state_clear(repo->remote_state);
+		FREE_AND_NULL(repo->remote_state);
+	}
+
+	strmap_for_each_entry(&repo->submodule_ref_stores, &iter, e)
+		ref_store_release(e->value);
+	strmap_clear(&repo->submodule_ref_stores, 1);
+
+	strmap_for_each_entry(&repo->worktree_ref_stores, &iter, e)
+		ref_store_release(e->value);
+	strmap_clear(&repo->worktree_ref_stores, 1);
+
+	repo_clear_path_cache(&repo->cached_paths);
+}
+
+int repo_read_index(struct repository *repo)
+{
+	int res;
+
+	/* Complete the double-reference */
+	if (!repo->index) {
+		ALLOC_ARRAY(repo->index, 1);
+		index_state_init(repo->index, repo);
+	} else if (repo->index->repo != repo) {
+		BUG("repo's index should point back at itself");
+	}
+
+	res = read_index_from(repo->index, repo->index_file, repo->gitdir);
+
+	prepare_repo_settings(repo);
+	if (repo->settings.command_requires_full_index)
+		ensure_full_index(repo->index);
+
+	/*
+	 * If sparse checkouts are in use, check whether paths with the
+	 * SKIP_WORKTREE attribute are missing from the worktree; if not,
+	 * clear that attribute for that path.
+	 */
+	clear_skip_worktree_from_present_files(repo->index);
+
+	return res;
+}
+
+int repo_hold_locked_index(struct repository *repo,
+			   struct lock_file *lf,
+			   int flags)
+{
+	if (!repo->index_file)
+		BUG("the repo hasn't been setup");
+	return hold_lock_file_for_update(lf, repo->index_file, flags);
+}