refs.c: migrate internal ref iteration to pass thru repository argument

In 60ce76d358 (refs: add repository argument to for_each_replace_ref,
2018-04-11) and 0d296c57ae (refs: allow for_each_replace_ref to handle
arbitrary repositories, 2018-04-11), for_each_replace_ref learned how
to iterate over refs by a given arbitrary repository.
New attempts in the object store conversion have shown that it is useful
to have the repository handle available that the refs iteration is
currently iterating over.

To achieve this goal we will need to add a repository argument to
each_ref_fn in refs.h. However as many callers rely on the signature
such a patch would be too large.

So convert the internals of the ref subsystem first to pass through a
repository argument without exposing the change to the user. Assume
the_repository for the passed through repository, although it is not
used anywhere yet.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs.c

@@ -1386,17 +1386,50 @@ struct ref_iterator *refs_ref_iterator_begin(
  * non-zero value, stop the iteration and return that value;
  * otherwise, return 0.
  */
-static int do_for_each_ref(struct ref_store *refs, const char *prefix,
-			   each_ref_fn fn, int trim, int flags, void *cb_data)
+static int do_for_each_repo_ref(struct repository *r, const char *prefix,
+				each_repo_ref_fn fn, int trim, int flags,
+				void *cb_data)
 {
 	struct ref_iterator *iter;
+	struct ref_store *refs = get_main_ref_store(r);
 
 	if (!refs)
 		return 0;
 
 	iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
 
-	return do_for_each_ref_iterator(iter, fn, cb_data);
+	return do_for_each_repo_ref_iterator(r, iter, fn, cb_data);
+}
+
+struct do_for_each_ref_help {
+	each_ref_fn *fn;
+	void *cb_data;
+};
+
+static int do_for_each_ref_helper(struct repository *r,
+				  const char *refname,
+				  const struct object_id *oid,
+				  int flags,
+				  void *cb_data)
+{
+	struct do_for_each_ref_help *hp = cb_data;
+
+	return hp->fn(refname, oid, flags, hp->cb_data);
+}
+
+static int do_for_each_ref(struct ref_store *refs, const char *prefix,
+			   each_ref_fn fn, int trim, int flags, void *cb_data)
+{
+	struct ref_iterator *iter;
+	struct do_for_each_ref_help hp = { fn, cb_data };
+
+	if (!refs)
+		return 0;
+
+	iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
+
+	return do_for_each_repo_ref_iterator(the_repository, iter,
+					do_for_each_ref_helper, &hp);
 }
 
 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
@@ -2025,10 +2058,12 @@ cleanup:
 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
 	struct ref_iterator *iter;
+	struct do_for_each_ref_help hp = { fn, cb_data };
 
 	iter = refs->be->reflog_iterator_begin(refs);
 
-	return do_for_each_ref_iterator(iter, fn, cb_data);
+	return do_for_each_repo_ref_iterator(the_repository, iter,
+					     do_for_each_ref_helper, &hp);
 }
 
 int for_each_reflog(each_ref_fn fn, void *cb_data)

refs.h

@@ -274,6 +274,16 @@ struct ref_transaction;
 typedef int each_ref_fn(const char *refname,
 			const struct object_id *oid, int flags, void *cb_data);
 
+/*
+ * The same as each_ref_fn, but also with a repository argument that
+ * contains the repository associated with the callback.
+ */
+typedef int each_repo_ref_fn(struct repository *r,
+			     const char *refname,
+			     const struct object_id *oid,
+			     int flags,
+			     void *cb_data);
+
 /*
  * The following functions invoke the specified callback function for
  * each reference indicated.  If the function ever returns a nonzero

refs/iterator.c

@@ -407,15 +407,15 @@ struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
 
 struct ref_iterator *current_ref_iter = NULL;
 
-int do_for_each_ref_iterator(struct ref_iterator *iter,
-			     each_ref_fn fn, void *cb_data)
+int do_for_each_repo_ref_iterator(struct repository *r, struct ref_iterator *iter,
+				  each_repo_ref_fn fn, void *cb_data)
 {
 	int retval = 0, ok;
 	struct ref_iterator *old_ref_iter = current_ref_iter;
 
 	current_ref_iter = iter;
 	while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
-		retval = fn(iter->refname, iter->oid, iter->flags, cb_data);
+		retval = fn(r, iter->refname, iter->oid, iter->flags, cb_data);
 		if (retval) {
 			/*
 			 * If ref_iterator_abort() returns ITER_ERROR,

refs/refs-internal.h

@@ -474,8 +474,9 @@ extern struct ref_iterator *current_ref_iter;
  * adapter between the callback style of reference iteration and the
  * iterator style.
  */
-int do_for_each_ref_iterator(struct ref_iterator *iter,
-			     each_ref_fn fn, void *cb_data);
+int do_for_each_repo_ref_iterator(struct repository *r,
+				  struct ref_iterator *iter,
+				  each_repo_ref_fn fn, void *cb_data);
 
 /*
  * Only include per-worktree refs in a do_for_each_ref*() iteration.