extern unsigned char* use_pack(struct packed_git *, struct pack_window **, unsigned long, unsigned int *);
extern void unuse_pack(struct pack_window **);
extern struct packed_git *add_packed_git(char *, int, int);
extern unsigned char* use_pack(struct packed_git *, struct pack_window **, unsigned long, unsigned int *);
extern void unuse_pack(struct pack_window **);
extern struct packed_git *add_packed_git(char *, int, int);