/* opaque */
struct git_istream;
-extern struct git_istream *open_istream(const unsigned char *, enum object_type *, unsigned long *, struct stream_filter *);
+extern struct git_istream *open_istream(const struct object_id *, enum object_type *, unsigned long *, struct stream_filter *);
extern int close_istream(struct git_istream *);
extern ssize_t read_istream(struct git_istream *, void *, size_t);