thodg/libgit2/src/libgit2/refdb.c

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• Hash : ef4ab298
  Author :
  Date : 2021-11-14T08:47:40
  

  refactor: `src` is now `src/libgit2`

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• src/libgit2/refdb.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "refdb.h"
  
  #include "git2/object.h"
  #include "git2/refs.h"
  #include "git2/refdb.h"
  #include "git2/sys/refdb_backend.h"
  
  #include "hash.h"
  #include "refs.h"
  #include "reflog.h"
  #include "posix.h"
  
  #define DEFAULT_NESTING_LEVEL	5
  #define MAX_NESTING_LEVEL		10
  
  int git_refdb_new(git_refdb **out, git_repository *repo)
  {
  	git_refdb *db;
  
  	GIT_ASSERT_ARG(out);
  	GIT_ASSERT_ARG(repo);
  
  	db = git__calloc(1, sizeof(*db));
  	GIT_ERROR_CHECK_ALLOC(db);
  
  	db->repo = repo;
  
  	*out = db;
  	GIT_REFCOUNT_INC(db);
  	return 0;
  }
  
  int git_refdb_open(git_refdb **out, git_repository *repo)
  {
  	git_refdb *db;
  	git_refdb_backend *dir;
  
  	GIT_ASSERT_ARG(out);
  	GIT_ASSERT_ARG(repo);
  
  	*out = NULL;
  
  	if (git_refdb_new(&db, repo) < 0)
  		return -1;
  
  	/* Add the default (filesystem) backend */
  	if (git_refdb_backend_fs(&dir, repo) < 0) {
  		git_refdb_free(db);
  		return -1;
  	}
  
  	db->repo = repo;
  	db->backend = dir;
  
  	*out = db;
  	return 0;
  }
  
  static void refdb_free_backend(git_refdb *db)
  {
  	if (db->backend)
  		db->backend->free(db->backend);
  }
  
  int git_refdb_set_backend(git_refdb *db, git_refdb_backend *backend)
  {
  	GIT_ERROR_CHECK_VERSION(backend, GIT_REFDB_BACKEND_VERSION, "git_refdb_backend");
  
  	if (!backend->exists || !backend->lookup || !backend->iterator ||
  	    !backend->write || !backend->rename || !backend->del ||
  	    !backend->has_log || !backend->ensure_log || !backend->free ||
  	    !backend->reflog_read || !backend->reflog_write ||
  	    !backend->reflog_rename || !backend->reflog_delete ||
  	    (backend->lock && !backend->unlock)) {
  		git_error_set(GIT_ERROR_REFERENCE, "incomplete refdb backend implementation");
  		return GIT_EINVALID;
  	}
  
  	refdb_free_backend(db);
  	db->backend = backend;
  
  	return 0;
  }
  
  int git_refdb_compress(git_refdb *db)
  {
  	GIT_ASSERT_ARG(db);
  
  	if (db->backend->compress)
  		return db->backend->compress(db->backend);
  
  	return 0;
  }
  
  void git_refdb__free(git_refdb *db)
  {
  	refdb_free_backend(db);
  	git__memzero(db, sizeof(*db));
  	git__free(db);
  }
  
  void git_refdb_free(git_refdb *db)
  {
  	if (db == NULL)
  		return;
  
  	GIT_REFCOUNT_DEC(db, git_refdb__free);
  }
  
  int git_refdb_exists(int *exists, git_refdb *refdb, const char *ref_name)
  {
  	GIT_ASSERT_ARG(exists);
  	GIT_ASSERT_ARG(refdb);
  	GIT_ASSERT_ARG(refdb->backend);
  
  	return refdb->backend->exists(exists, refdb->backend, ref_name);
  }
  
  int git_refdb_lookup(git_reference **out, git_refdb *db, const char *ref_name)
  {
  	git_reference *ref;
  	int error;
  
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(db->backend);
  	GIT_ASSERT_ARG(out);
  	GIT_ASSERT_ARG(ref_name);
  
  	error = db->backend->lookup(&ref, db->backend, ref_name);
  	if (error < 0)
  		return error;
  
  	GIT_REFCOUNT_INC(db);
  	ref->db = db;
  
  	*out = ref;
  	return 0;
  }
  
  int git_refdb_resolve(
  	git_reference **out,
  	git_refdb *db,
  	const char *ref_name,
  	int max_nesting)
  {
  	git_reference *ref = NULL;
  	int error = 0, nesting;
  
  	*out = NULL;
  
  	if (max_nesting > MAX_NESTING_LEVEL)
  		max_nesting = MAX_NESTING_LEVEL;
  	else if (max_nesting < 0)
  		max_nesting = DEFAULT_NESTING_LEVEL;
  
  	if ((error = git_refdb_lookup(&ref, db, ref_name)) < 0)
  		goto out;
  
  	for (nesting = 0; nesting < max_nesting; nesting++) {
  		git_reference *resolved;
  
  		if (ref->type == GIT_REFERENCE_DIRECT)
  			break;
  
  		if ((error = git_refdb_lookup(&resolved, db, git_reference_symbolic_target(ref))) < 0) {
  			/* If we found a symbolic reference with a nonexistent target, return it. */
  			if (error == GIT_ENOTFOUND) {
  				error = 0;
  				*out = ref;
  				ref = NULL;
  			}
  			goto out;
  		}
  
  		git_reference_free(ref);
  		ref = resolved;
  	}
  
  	if (ref->type != GIT_REFERENCE_DIRECT && max_nesting != 0) {
  		git_error_set(GIT_ERROR_REFERENCE,
  			"cannot resolve reference (>%u levels deep)", max_nesting);
  		error = -1;
  		goto out;
  	}
  
  	*out = ref;
  	ref = NULL;
  out:
  	git_reference_free(ref);
  	return error;
  }
  
  int git_refdb_iterator(git_reference_iterator **out, git_refdb *db, const char *glob)
  {
  	int error;
  
  	if (!db->backend || !db->backend->iterator) {
  		git_error_set(GIT_ERROR_REFERENCE, "this backend doesn't support iterators");
  		return -1;
  	}
  
  	if ((error = db->backend->iterator(out, db->backend, glob)) < 0)
  		return error;
  
  	GIT_REFCOUNT_INC(db);
  	(*out)->db = db;
  
  	return 0;
  }
  
  int git_refdb_iterator_next(git_reference **out, git_reference_iterator *iter)
  {
  	int error;
  
  	if ((error = iter->next(out, iter)) < 0)
  		return error;
  
  	GIT_REFCOUNT_INC(iter->db);
  	(*out)->db = iter->db;
  
  	return 0;
  }
  
  int git_refdb_iterator_next_name(const char **out, git_reference_iterator *iter)
  {
  	return iter->next_name(out, iter);
  }
  
  void git_refdb_iterator_free(git_reference_iterator *iter)
  {
  	GIT_REFCOUNT_DEC(iter->db, git_refdb__free);
  	iter->free(iter);
  }
  
  int git_refdb_write(git_refdb *db, git_reference *ref, int force, const git_signature *who, const char *message, const git_oid *old_id, const char *old_target)
  {
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(db->backend);
  
  	GIT_REFCOUNT_INC(db);
  	ref->db = db;
  
  	return db->backend->write(db->backend, ref, force, who, message, old_id, old_target);
  }
  
  int git_refdb_rename(
  	git_reference **out,
  	git_refdb *db,
  	const char *old_name,
  	const char *new_name,
  	int force,
  	const git_signature *who,
  	const char *message)
  {
  	int error;
  
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(db->backend);
  
  	error = db->backend->rename(out, db->backend, old_name, new_name, force, who, message);
  	if (error < 0)
  		return error;
  
  	if (out) {
  		GIT_REFCOUNT_INC(db);
  		(*out)->db = db;
  	}
  
  	return 0;
  }
  
  int git_refdb_delete(struct git_refdb *db, const char *ref_name, const git_oid *old_id, const char *old_target)
  {
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(db->backend);
  
  	return db->backend->del(db->backend, ref_name, old_id, old_target);
  }
  
  int git_refdb_reflog_read(git_reflog **out, git_refdb *db,  const char *name)
  {
  	int error;
  
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(db->backend);
  
  	if ((error = db->backend->reflog_read(out, db->backend, name)) < 0)
  		return error;
  
  	GIT_REFCOUNT_INC(db);
  	(*out)->db = db;
  
  	return 0;
  }
  
  int git_refdb_should_write_reflog(int *out, git_refdb *db, const git_reference *ref)
  {
  	int error, logall;
  
  	error = git_repository__configmap_lookup(&logall, db->repo, GIT_CONFIGMAP_LOGALLREFUPDATES);
  	if (error < 0)
  		return error;
  
  	/* Defaults to the opposite of the repo being bare */
  	if (logall == GIT_LOGALLREFUPDATES_UNSET)
  		logall = !git_repository_is_bare(db->repo);
  
  	*out = 0;
  	switch (logall) {
  	case GIT_LOGALLREFUPDATES_FALSE:
  		*out = 0;
  		break;
  
  	case GIT_LOGALLREFUPDATES_TRUE:
  		/* Only write if it already has a log,
  		 * or if it's under heads/, remotes/ or notes/
  		 */
  		*out = git_refdb_has_log(db, ref->name) ||
  			!git__prefixcmp(ref->name, GIT_REFS_HEADS_DIR) ||
  			!git__strcmp(ref->name, GIT_HEAD_FILE) ||
  			!git__prefixcmp(ref->name, GIT_REFS_REMOTES_DIR) ||
  			!git__prefixcmp(ref->name, GIT_REFS_NOTES_DIR);
  		break;
  
  	case GIT_LOGALLREFUPDATES_ALWAYS:
  		*out = 1;
  		break;
  	}
  
  	return 0;
  }
  
  int git_refdb_should_write_head_reflog(int *out, git_refdb *db, const git_reference *ref)
  {
  	git_reference *head = NULL, *resolved = NULL;
  	const char *name;
  	int error;
  
  	*out = 0;
  
  	if (ref->type == GIT_REFERENCE_SYMBOLIC) {
  		error = 0;
  		goto out;
  	}
  
  	if ((error = git_refdb_lookup(&head, db, GIT_HEAD_FILE)) < 0)
  		goto out;
  
  	if (git_reference_type(head) == GIT_REFERENCE_DIRECT)
  		goto out;
  
  	/* Go down the symref chain until we find the branch */
  	if ((error = git_refdb_resolve(&resolved, db, git_reference_symbolic_target(head), -1)) < 0) {
  		if (error != GIT_ENOTFOUND)
  			goto out;
  		error = 0;
  		name = git_reference_symbolic_target(head);
  	} else if (git_reference_type(resolved) == GIT_REFERENCE_SYMBOLIC) {
  		name = git_reference_symbolic_target(resolved);
  	} else {
  		name = git_reference_name(resolved);
  	}
  
  	if (strcmp(name, ref->name))
  		goto out;
  
  	*out = 1;
  
  out:
  	git_reference_free(resolved);
  	git_reference_free(head);
  	return error;
  }
  
  int git_refdb_has_log(git_refdb *db, const char *refname)
  {
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(refname);
  
  	return db->backend->has_log(db->backend, refname);
  }
  
  int git_refdb_ensure_log(git_refdb *db, const char *refname)
  {
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(refname);
  
  	return db->backend->ensure_log(db->backend, refname);
  }
  
  int git_refdb_init_backend(git_refdb_backend *backend, unsigned int version)
  {
  	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
  		backend, version, git_refdb_backend, GIT_REFDB_BACKEND_INIT);
  	return 0;
  }
  
  int git_refdb_lock(void **payload, git_refdb *db, const char *refname)
  {
  	GIT_ASSERT_ARG(payload);
  	GIT_ASSERT_ARG(db);
  	GIT_ASSERT_ARG(refname);
  
  	if (!db->backend->lock) {
  		git_error_set(GIT_ERROR_REFERENCE, "backend does not support locking");
  		return -1;
  	}
  
  	return db->backend->lock(payload, db->backend, refname);
  }
  
  int git_refdb_unlock(git_refdb *db, void *payload, int success, int update_reflog, const git_reference *ref, const git_signature *sig, const char *message)
  {
  	GIT_ASSERT_ARG(db);
  
  	return db->backend->unlock(db->backend, payload, success, update_reflog, ref, sig, message);
  }
  

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