typedef struct VacFs VacFs;

typedef struct VacFs VacFs;
typedef struct VacDir VacDir;
typedef struct VacFile VacFile;
typedef struct VacDirEnum VacDirEnum;

#pragma incomplete VacFile
#pragma incomplete VacDirEnum

/*
* Mode bits
*/
enum
{
ModeOtherExec = (1<<0),
ModeOtherWrite = (1<<1),
ModeOtherRead = (1<<2),
ModeGroupExec = (1<<3),
ModeGroupWrite = (1<<4),
ModeGroupRead = (1<<5),
ModeOwnerExec = (1<<6),
ModeOwnerWrite = (1<<7),
ModeOwnerRead = (1<<8),
ModeSticky = (1<<9),
ModeSetUid = (1<<10),
ModeSetGid = (1<<11),
ModeAppend = (1<<12), /* append only file */
ModeExclusive = (1<<13), /* lock file - plan 9 */
ModeLink = (1<<14), /* sym link */
ModeDir = (1<<15), /* duplicate of DirEntry */
ModeHidden = (1<<16), /* MS-DOS */
ModeSystem = (1<<17), /* MS-DOS */
ModeArchive = (1<<18), /* MS-DOS */
ModeTemporary = (1<<19), /* MS-DOS */
ModeSnapshot = (1<<20), /* read only snapshot */
ModeDevice = (1<<21), /* Unix device */
ModeNamedPipe = (1<<22) /* Unix named pipe */
};

enum
{
MetaMagic = 0x5656fc79,
MetaHeaderSize = 12,
MetaIndexSize = 4,
IndexEntrySize = 8,
DirMagic = 0x1c4d9072
};

enum
{
DirPlan9Entry = 1, /* not valid in version >= 9 */
DirNTEntry, /* not valid in version >= 9 */
DirQidSpaceEntry,
DirGenEntry /* not valid in version >= 9 */
};

struct VacDir
{
char *elem; /* path element */
ulong entry; /* entry in directory for data */
ulong gen; /* generation of data entry */
ulong mentry; /* entry in directory for meta */
ulong mgen; /* generation of meta entry */
uvlong size; /* size of file */
uvlong qid; /* unique file id */

char *uid; /* owner id */
char *gid; /* group id */
char *mid; /* last modified by */
ulong mtime; /* last modified time */
ulong mcount; /* number of modifications: can wrap! */
ulong ctime; /* directory entry last changed */
ulong atime; /* last time accessed */
ulong mode; /* various mode bits */

/* plan 9 */
int plan9;
uvlong p9path;
ulong p9version;

/* sub space of qid */
int qidspace;
uvlong qidoffset; /* qid offset */
uvlong qidmax; /* qid maximum */
};

struct VacFs
{
char name[128];
uchar score[VtScoreSize];
VacFile *root;
VtConn *z;
int mode;
int bsize;
uvlong qid;
VtCache *cache;
};

VacFs *vacfsopen(VtConn *z, char *file, int mode, int ncache);
VacFs *vacfsopenscore(VtConn *z, u8int *score, int mode, int ncache);
VacFs *vacfscreate(VtConn *z, int bsize, int ncache);
void vacfsclose(VacFs *fs);
int vacfssync(VacFs *fs);
int vacfssnapshot(VacFs *fs, char *src, char *dst);
int vacfsgetscore(VacFs *fs, u8int *score);
int vacfsgetmaxqid(VacFs*, uvlong*);
void vacfsjumpqid(VacFs*, uvlong);

VacFile *vacfsgetroot(VacFs *fs);
VacFile *vacfileopen(VacFs *fs, char *path);
VacFile *vacfilecreate(VacFile *file, char *elem, ulong perm);
VacFile *vacfilewalk(VacFile *file, char *elem);
int vacfileremove(VacFile *file);
int vacfileread(VacFile *file, void *buf, int n, vlong offset);
int vacfileblockscore(VacFile *file, u32int, u8int*);
int vacfilewrite(VacFile *file, void *buf, int n, vlong offset);
uvlong vacfilegetid(VacFile *file);
ulong vacfilegetmcount(VacFile *file);
int vacfileisdir(VacFile *file);
int vacfileisroot(VacFile *file);
ulong vacfilegetmode(VacFile *file);
int vacfilegetsize(VacFile *file, uvlong *size);
int vacfilegetdir(VacFile *file, VacDir *dir);
int vacfilesetdir(VacFile *file, VacDir *dir);
VacFile *vacfilegetparent(VacFile *file);
int vacfileflush(VacFile*, int);
VacFile *vacfileincref(VacFile*);
int vacfiledecref(VacFile*);
int vacfilesetsize(VacFile *f, uvlong size);

int vacfilegetentries(VacFile *f, VtEntry *e, VtEntry *me);
int vacfilesetentries(VacFile *f, VtEntry *e, VtEntry *me);

void vdcleanup(VacDir *dir);
void vdcopy(VacDir *dst, VacDir *src);
int vacfilesetqidspace(VacFile*, u64int, u64int);
uvlong vacfilegetqidoffset(VacFile*);

VacDirEnum *vdeopen(VacFile*);
int vderead(VacDirEnum*, VacDir *);
void vdeclose(VacDirEnum*);
int vdeunread(VacDirEnum*);

int vacfiledsize(VacFile *f);
int sha1matches(VacFile *f, ulong b, uchar *buf, int n);