(In these examples, we'll use an informal notation similar to JSON to indicate the contents of structures sent over the wire.)
Let's say the client wants to retrieve file /a. So it
sends the following:
{
tag: 0,
verb: GET,
path: "/a",
}
The server replies
{
tag: 0,
flags: 3, // 3 == valid|done
rev: 5,
value: "hello",
}
Set usually takes much longer than get, so here we'll see replies come out of order:
{
tag: 0,
verb: SET,
path: "/a",
rev: -1,
value: "goodbye",
}
{
tag: 1,
verb: GET,
path: "/a",
}
The server replies immediately:
{
tag: 1,
flags: 3, // 3 == valid|done
rev: 5,
value: "hello",
}
Some time later, the set operation finishes:
{
tag: 0,
flags: 3, // 3 == valid|done
rev: 6,
}
Now, the client can issue the same get request once more:
{
tag: 1,
verb: GET,
path: "/a",
}
This time, the server replies:
{
tag: 1,
flags: 3, // 3 == valid|done
rev: 6,
value: "goodbye",
}