khash: move oid hash table definition

Move the oid khash table definition to khash.h and define a typedef for
it, similar to the one we have for unsigned char pointers. Define
variants that are maps as well.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

khash.h

@@ -332,4 +332,22 @@ typedef kh_sha1_t khash_sha1;
 KHASH_INIT(sha1_pos, const unsigned char *, int, 1, sha1hash, __kh_oid_cmp)
 typedef kh_sha1_pos_t khash_sha1_pos;
 
+static inline unsigned int oid_hash(struct object_id oid)
+{
+	return sha1hash(oid.hash);
+}
+
+static inline int oid_equal(struct object_id a, struct object_id b)
+{
+	return oideq(&a, &b);
+}
+
+KHASH_INIT(oid, struct object_id, int, 0, oid_hash, oid_equal)
+
+KHASH_INIT(oid_map, struct object_id, void *, 1, oid_hash, oid_equal)
+typedef kh_oid_t khash_oid_map;
+
+KHASH_INIT(oid_pos, struct object_id, int, 1, oid_hash, oid_equal)
+typedef kh_oid_pos_t khash_oid_pos;
+
 #endif /* __AC_KHASH_H */

oidset.h

@@ -16,18 +16,6 @@
  *      table overhead.
  */
 
-static inline unsigned int oid_hash(struct object_id oid)
-{
-	return sha1hash(oid.hash);
-}
-
-static inline int oid_equal(struct object_id a, struct object_id b)
-{
-	return oideq(&a, &b);
-}
-
-KHASH_INIT(oid, struct object_id, int, 0, oid_hash, oid_equal)
-
 /**
  * A single oidset; should be zero-initialized (or use OIDSET_INIT).
  */