public void Integration_test()
{
var p0 = Replica.Empty(ReplicaId.New("p")).ApplyCmd(new Doc().DownField("key").Assign("A"));
var q0 = Merge(Replica.Empty(ReplicaId.New("q")), p0);
// Assert that p0 and q0 are converged
Converged(p0, q0);
var p1 = p0.ApplyCmd(new Doc().DownField("key").Assign("B"));
var q1 = q0.ApplyCmd(new Doc().DownField("key").Assign("C"));
// Assert that p1 and q1 are diverged
Diverged(p1, q1);
var p2 = Merge(p1, q1);
var q2 = Merge(q1, p1);
// Assert that p2 and q2 are converged again.
Converged(p2, q2);
}
private static Replica Merge(Replica a, Replica b) => a.ApplyRemoteOps(b.GeneratedOps);
private static void Converged(Replica a, Replica b, Replica c)
{
Converged(a, b);
Converged(b, c);
}
public Node ApplyOp(Operation op, Replica replica)
{
var view = op.Cursor.View();
switch (view)
{
case Cursor.Leaf l:
{
switch (this)
{
case ListNode ln:
{
IEnumerable <Operation> ConcurrentOpsSince(bigint count)
{
var allOps = replica.GeneratedOps.Append(replica.ReceivedOps);
throw new NotImplementedException();
}
var concurrentOps = ConcurrentOpsSince(op.Id.OpsCounter);
if (concurrentOps.Length() > 1 &&
concurrentOps.Select(x => x.Mutation).OfType <MoveVerticalM>().Length() >= 1)
{
// Before applying an operation we save the order in orderArchive.
// It's a Map whose key is the lamport timestamp counter value.
// To improve performance and save disk space, we don't save the
// order before assign operations, since they don't change the order.
// Now there might be this situation: Alice did an assign and then a
// move op, while Bob did a move op. Now Bobs op comes in and
// Alice resets her order to the order with counter value like the
// incoming op. However, locally exists no such saved order, since
// she has done an assign op at that count. Therefore she resets
// to the next higher saved order.
// This fix is implemented by getting all orders whose counter is
// greater equals than the counter of the incoming op and then
// choosing the earliest order of those:
var newerOrders = ln.OrderArchive.Filter((k, v) => k >= op.Id.OpsCounter);
// restore the order
// TODO:
// val ctx1 =
// if (newerOrders.nonEmpty) ln.copy(order = newerOrders.minBy {
// case (c, _) => c
// }._2)
// else this
throw new NotImplementedException();
// Node ctx1 = this;
// return ctx1.ApplyMany(concurrentOps.OrderBy(x => x.Id));
}
else
{
// The op was done without me doing an op concurrently, so there is
// no need to restore anything. Just apply the op.
return(ApplyAtLeaf(op, replica));
}
}
default: return(ApplyAtLeaf(op, replica));
}
throw new InvalidOperationException("Invalid Cursor type");
}
case Cursor.Branch bn:
{
var child0 = GetChild(bn.Head);
var child1 = child0.ApplyOp(op.Copy(cursor: bn.Tail), replica);
var ctx1 = AddId(bn.Head, op.Id, op.Mutation);
return(ctx1.AddNode(bn.Head, child1));
}
}
return(this);
}