Merge branch 'nd/files-backend-git-dir'

The "submodule" specific field in the ref_store structure is
replaced with a more generic "gitdir" that can later be used also
when dealing with ref_store that represents the set of refs visible
from the other worktrees.

* nd/files-backend-git-dir: (28 commits)
  refs.h: add a note about sorting order of for_each_ref_*
  t1406: new tests for submodule ref store
  t1405: some basic tests on main ref store
  t/helper: add test-ref-store to test ref-store functions
  refs: delete pack_refs() in favor of refs_pack_refs()
  files-backend: avoid ref api targeting main ref store
  refs: new transaction related ref-store api
  refs: add new ref-store api
  refs: rename get_ref_store() to get_submodule_ref_store() and make it public
  files-backend: replace submodule_allowed check in files_downcast()
  refs: move submodule code out of files-backend.c
  path.c: move some code out of strbuf_git_path_submodule()
  refs.c: make get_main_ref_store() public and use it
  refs.c: kill register_ref_store(), add register_submodule_ref_store()
  refs.c: flatten get_ref_store() a bit
  refs: rename lookup_ref_store() to lookup_submodule_ref_store()
  refs.c: introduce get_main_ref_store()
  files-backend: remove the use of git_path()
  files-backend: add and use files_ref_path()
  files-backend: add and use files_reflog_path()
  ...

1 files changed, 103 insertions, 3 deletions

diff --git a/refs.h b/refs.h
index 3df0d45ebb..49e97d7d5f 100644
--- a/refs.h
+++ b/refs.h
@@ -1,6 +1,11 @@
 #ifndef REFS_H
 #define REFS_H
 
+struct object_id;
+struct ref_store;
+struct strbuf;
+struct string_list;
+
 /*
  * Resolve a reference, recursively following symbolic refererences.
  *
@@ -52,16 +57,50 @@
 #define RESOLVE_REF_NO_RECURSE 0x02
 #define RESOLVE_REF_ALLOW_BAD_NAME 0x04
 
+const char *refs_resolve_ref_unsafe(struct ref_store *refs,
+				    const char *refname,
+				    int resolve_flags,
+				    unsigned char *sha1,
+				    int *flags);
 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 			       unsigned char *sha1, int *flags);
 
+char *refs_resolve_refdup(struct ref_store *refs,
+			  const char *refname, int resolve_flags,
+			  unsigned char *sha1, int *flags);
 char *resolve_refdup(const char *refname, int resolve_flags,
 		     unsigned char *sha1, int *flags);
 
+int refs_read_ref_full(struct ref_store *refs, const char *refname,
+		       int resolve_flags, unsigned char *sha1, int *flags);
 int read_ref_full(const char *refname, int resolve_flags,
 		  unsigned char *sha1, int *flags);
 int read_ref(const char *refname, unsigned char *sha1);
 
+/*
+ * Return 0 if a reference named refname could be created without
+ * conflicting with the name of an existing reference. Otherwise,
+ * return a negative value and write an explanation to err. If extras
+ * is non-NULL, it is a list of additional refnames with which refname
+ * is not allowed to conflict. If skip is non-NULL, ignore potential
+ * conflicts with refs in skip (e.g., because they are scheduled for
+ * deletion in the same operation). Behavior is undefined if the same
+ * name is listed in both extras and skip.
+ *
+ * Two reference names conflict if one of them exactly matches the
+ * leading components of the other; e.g., "foo/bar" conflicts with
+ * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
+ * "foo/barbados".
+ *
+ * extras and skip must be sorted.
+ */
+
+int refs_verify_refname_available(struct ref_store *refs,
+				  const char *refname,
+				  const struct string_list *extra,
+				  const struct string_list *skip,
+				  struct strbuf *err);
+
 int ref_exists(const char *refname);
 
 int should_autocreate_reflog(const char *refname);
@@ -78,6 +117,8 @@ extern int refs_init_db(struct strbuf *err);
  * Symbolic references are considered unpeelable, even if they
  * ultimately resolve to a peelable tag.
  */
+int refs_peel_ref(struct ref_store *refs, const char *refname,
+		  unsigned char *sha1);
 int peel_ref(const char *refname, unsigned char *sha1);
 
 /**
@@ -189,8 +230,19 @@ typedef int each_ref_fn(const char *refname,
  * it is not safe to modify references while an iteration is in
  * progress, unless the same callback function invocation that
  * modifies the reference also returns a nonzero value to immediately
- * stop the iteration.
+ * stop the iteration. Returned references are sorted.
  */
+int refs_for_each_ref(struct ref_store *refs,
+		      each_ref_fn fn, void *cb_data);
+int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
+			 each_ref_fn fn, void *cb_data);
+int refs_for_each_tag_ref(struct ref_store *refs,
+			  each_ref_fn fn, void *cb_data);
+int refs_for_each_branch_ref(struct ref_store *refs,
+			     each_ref_fn fn, void *cb_data);
+int refs_for_each_remote_ref(struct ref_store *refs,
+			     each_ref_fn fn, void *cb_data);
+
 int head_ref(each_ref_fn fn, void *cb_data);
 int for_each_ref(each_ref_fn fn, void *cb_data);
 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
@@ -220,6 +272,7 @@ int head_ref_namespaced(each_ref_fn fn, void *cb_data);
 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
 
 /* can be used to learn about broken ref and symref */
+int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data);
 int for_each_rawref(each_ref_fn fn, void *cb_data);
 
 static inline const char *has_glob_specials(const char *pattern)
@@ -243,7 +296,7 @@ void warn_dangling_symrefs(FILE *fp, const char *msg_fmt,
  * Write a packed-refs file for the current repository.
  * flags: Combination of the above PACK_REFS_* flags.
  */
-int pack_refs(unsigned int flags);
+int refs_pack_refs(struct ref_store *refs, unsigned int flags);
 
 /*
  * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
@@ -258,6 +311,8 @@ int pack_refs(unsigned int flags);
 /*
  * Setup reflog before using. Fill in err and return -1 on failure.
  */
+int refs_create_reflog(struct ref_store *refs, const char *refname,
+		       int force_create, struct strbuf *err);
 int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
 
 /** Reads log for the value of ref during at_time. **/
@@ -267,6 +322,7 @@ int read_ref_at(const char *refname, unsigned int flags,
 		unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
 
 /** Check if a particular reflog exists */
+int refs_reflog_exists(struct ref_store *refs, const char *refname);
 int reflog_exists(const char *refname);
 
 /*
@@ -276,6 +332,10 @@ int reflog_exists(const char *refname);
  * exists, regardless of its old value. It is an error for old_sha1 to
  * be NULL_SHA1. flags is passed through to ref_transaction_delete().
  */
+int refs_delete_ref(struct ref_store *refs, const char *msg,
+		    const char *refname,
+		    const unsigned char *old_sha1,
+		    unsigned int flags);
 int delete_ref(const char *msg, const char *refname,
 	       const unsigned char *old_sha1, unsigned int flags);
 
@@ -285,9 +345,12 @@ int delete_ref(const char *msg, const char *refname,
  * an all-or-nothing transaction). flags is passed through to
  * ref_transaction_delete().
  */
+int refs_delete_refs(struct ref_store *refs, struct string_list *refnames,
+		     unsigned int flags);
 int delete_refs(struct string_list *refnames, unsigned int flags);
 
 /** Delete a reflog */
+int refs_delete_reflog(struct ref_store *refs, const char *refname);
 int delete_reflog(const char *refname);
 
 /* iterate over reflog entries */
@@ -296,13 +359,20 @@ typedef int each_reflog_ent_fn(
 		const char *committer, unsigned long timestamp,
 		int tz, const char *msg, void *cb_data);
 
+int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
+			     each_reflog_ent_fn fn, void *cb_data);
+int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
+				     const char *refname,
+				     each_reflog_ent_fn fn,
+				     void *cb_data);
 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 
 /*
  * Calls the specified function for each reflog file until it returns nonzero,
- * and returns the value
+ * and returns the value. Reflog file order is unspecified.
  */
+int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
 int for_each_reflog(each_ref_fn fn, void *cb_data);
 
 #define REFNAME_ALLOW_ONELEVEL 1
@@ -323,8 +393,12 @@ const char *prettify_refname(const char *refname);
 char *shorten_unambiguous_ref(const char *refname, int strict);
 
 /** rename ref, return 0 on success **/
+int refs_rename_ref(struct ref_store *refs, const char *oldref,
+		    const char *newref, const char *logmsg);
 int rename_ref(const char *oldref, const char *newref, const char *logmsg);
 
+int refs_create_symref(struct ref_store *refs, const char *refname,
+		       const char *target, const char *logmsg);
 int create_symref(const char *refname, const char *target, const char *logmsg);
 
 /*
@@ -347,6 +421,8 @@ enum action_on_err {
  * Begin a reference transaction.  The reference transaction must
  * be freed by calling ref_transaction_free().
  */
+struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
+						    struct strbuf *err);
 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
 
 /*
@@ -481,6 +557,9 @@ void ref_transaction_free(struct ref_transaction *transaction);
  * ref_transaction_update(). Handle errors as requested by the `onerr`
  * argument.
  */
+int refs_update_ref(struct ref_store *refs, const char *msg, const char *refname,
+		    const unsigned char *new_sha1, const unsigned char *old_sha1,
+		    unsigned int flags, enum action_on_err onerr);
 int update_ref(const char *msg, const char *refname,
 	       const unsigned char *new_sha1, const unsigned char *old_sha1,
 	       unsigned int flags, enum action_on_err onerr);
@@ -547,6 +626,14 @@ typedef void reflog_expiry_cleanup_fn(void *cb_data);
  * enum expire_reflog_flags. The three function pointers are described
  * above. On success, return zero.
  */
+int refs_reflog_expire(struct ref_store *refs,
+		       const char *refname,
+		       const unsigned char *sha1,
+		       unsigned int flags,
+		       reflog_expiry_prepare_fn prepare_fn,
+		       reflog_expiry_should_prune_fn should_prune_fn,
+		       reflog_expiry_cleanup_fn cleanup_fn,
+		       void *policy_cb_data);
 int reflog_expire(const char *refname, const unsigned char *sha1,
 		  unsigned int flags,
 		  reflog_expiry_prepare_fn prepare_fn,
@@ -556,4 +643,17 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 
 int ref_storage_backend_exists(const char *name);
 
+struct ref_store *get_main_ref_store(void);
+/*
+ * Return the ref_store instance for the specified submodule. For the
+ * main repository, use submodule==NULL; such a call cannot fail. For
+ * a submodule, the submodule must exist and be a nonbare repository,
+ * otherwise return NULL. If the requested reference store has not yet
+ * been initialized, initialize it first.
+ *
+ * For backwards compatibility, submodule=="" is treated the same as
+ * submodule==NULL.
+ */
+struct ref_store *get_submodule_ref_store(const char *submodule);
+
 #endif /* REFS_H */