[PATCH v3 5/7] refs: add pseudorefs array and iteration functions

[Andy Koppe <andy.koppe@gmail.com>]

Define const array 'pseudorefs' with the names of the pseudorefs that
are documented in gitrevisions.1, and add functions for_each_pseudoref()
and refs_for_each_pseudoref() for iterating over them.

The functions process the pseudorefs in the same way as head_ref() and
refs_head_ref() process HEAD, invoking an each_ref_fn callback on each
pseudoref that exists.

This is in preparation for adding pseudorefs to log decorations.

Signed-off-by: Andy Koppe <andy.koppe@gmail.com>
---
 refs.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 refs.h |  5 +++++
 2 files changed, 47 insertions(+)

diff --git a/refs.c b/refs.c
index fcae5dddc6..aa7e4c02c5 100644
--- a/refs.c
+++ b/refs.c
@@ -65,6 +65,21 @@ static unsigned char refname_disposition[256] = {
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
 };
 
+/*
+ * List of documented pseudorefs. This needs to be kept in sync with the list
+ * in Documentation/revisions.txt.
+ */
+static const char *const pseudorefs[] = {
+	"FETCH_HEAD",
+	"ORIG_HEAD",
+	"MERGE_HEAD",
+	"REBASE_HEAD",
+	"CHERRY_PICK_HEAD",
+	"REVERT_HEAD",
+	"BISECT_HEAD",
+	"AUTO_MERGE",
+};
+
 struct ref_namespace_info ref_namespace[] = {
 	[NAMESPACE_HEAD] = {
 		.ref = "HEAD",
@@ -1549,6 +1564,33 @@ int head_ref(each_ref_fn fn, void *cb_data)
 	return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
 }
 
+int refs_for_each_pseudoref(struct ref_store *refs,
+			    each_ref_fn fn, void *cb_data)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pseudorefs); i++) {
+		struct object_id oid;
+		int flag;
+
+		if (refs_resolve_ref_unsafe(refs, pseudorefs[i],
+					    RESOLVE_REF_READING, &oid, &flag)) {
+			int ret = fn(pseudorefs[i], &oid, flag, cb_data);
+
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+int for_each_pseudoref(each_ref_fn fn, void *cb_data)
+{
+	return refs_for_each_pseudoref(get_main_ref_store(the_repository),
+				       fn, cb_data);
+}
+
 struct ref_iterator *refs_ref_iterator_begin(
 		struct ref_store *refs,
 		const char *prefix,
diff --git a/refs.h b/refs.h
index 23211a5ea1..7b55cced31 100644
--- a/refs.h
+++ b/refs.h
@@ -320,6 +320,8 @@ typedef int each_repo_ref_fn(struct repository *r,
  */
 int refs_head_ref(struct ref_store *refs,
 		  each_ref_fn fn, void *cb_data);
+int refs_for_each_pseudoref(struct ref_store *refs,
+			    each_ref_fn fn, void *cb_data);
 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,
@@ -334,6 +336,9 @@ int refs_for_each_remote_ref(struct ref_store *refs,
 /* just iterates the head ref. */
 int head_ref(each_ref_fn fn, void *cb_data);
 
+/* iterates pseudorefs. */
+int for_each_pseudoref(each_ref_fn fn, void *cb_data);
+
 /* iterates all refs. */
 int for_each_ref(each_ref_fn fn, void *cb_data);
 
-- 
2.42.GIT