include "venti.m";
venti := load Venti Venti->PATH;
Session: import venti;

init:			fn();
unpackentry:	fn(d: array of byte): ref Entry;
unpackroot:	fn(d: array of byte): ref Root;

Session: adt {
	new:		fn(fd: ref Sys->FD): ref Session;
	read:		fn(s: self ref Session, score: Venti->Score, etype: int, maxn: int): array of byte;
	write:	fn(s: self ref Session, etype: int, buf: array of byte): (int, Venti->Score);
	sync:	fn(s: self ref Session): int;
};

Score: adt {
	a: array of byte;
	eq:		fn(a: self Score, b: Score): int;
	text:		fn(a: self Score): string;
	parse:	fn(s: string): (int, Score);
	zero:		fn(): Score;
};

s.new(fd)

New performs the initial handshake with the Venti server, returning established Session.

s.read(score, etype, maxn)

Read tries to retrieve the block corresponding to score, and of type etype. The block must be no longer than maxn bytes. Etype is conventionally one of the constants Roottype, Dirtype, Datatype or Pointertype[0-9], where the different Pointertypes represent different depth levels within a Venti tree.

s.write(etype, buf)

Write writes the data in buf to the Venti server. The block will be tagged with type etype. It returns a tuple, say (ok, score); on error, ok is -1, otherwise ok is 0 and score contains the Venti score for the block that has been written.

s.sync()

Sync tells the Venti server to make sure that all data is committed to active storage.