#include <u.h>#include <libc.h>#include <bio.h>#include <disk.h> /* avl.c */typedef struct Avl Avl;typedef struct Avltree Avltree;typedef struct Avlwalk Avlwalk; #pragma incomplete Avltree#pragma incomplete Avlwalk struct Avl{	Avl *p;	/* parent */	Avl *n[2];	/* children */	int bal;	/* balance bits */}; Avltree *mkavltree(int(*cmp)(Avl*, Avl*));void insertavl(Avltree *tree, Avl *new, Avl **oldp); Avl *lookupavl(Avltree *tree, Avl *key);void deleteavl(Avltree *tree, Avl *key, Avl **oldp);Avlwalk *avlwalk(Avltree *tree);Avl *avlnext(Avlwalk *walk);Avl	*avlprev(Avlwalk *walk);void endwalk(Avlwalk *walk); /* db.c */typedef struct Db Db;typedef struct Entry Entry;struct Entry{	Avl a;	char *name;	struct {		char *name;		char *uid;		char *gid;		ulong mtime;		ulong mode;		int mark;		vlong length;	} d;};  typedef struct Db Db;struct Db{	Avltree *avl;	int fd;};Db *opendb(char*);int finddb(Db*, char*, Dir*);void removedb(Db*, char*);void insertdb(Db*, char*, Dir*);int markdb(Db*, char*, Dir*); /* util.c */void *erealloc(void*, int);void *emalloc(int);char *estrdup(char*);char *atom(char*);char *unroot(char*, char*); /* revproto.c */int revrdproto(char*, char*, char*, Protoenum*, Protowarn*, void*);