durability once again

[William la Forge]

Seems like I've done a number of partial implementations of durable / incdes. The last one that was finished was for the old JActor. This time will be interesting because there are a number of differences...

First, we have decoupled durability from actors. Some actors may have durable state,, but durable structures have nothing to do with actors. For too long I thought that actors should be used for everything, but this is clearly not the case for immutable durable data.

Second, We are keeping the durable structures pure. They will only contain immutables, and only a few of them. Application objects need not apply.

And finally, the durable data will all be immutables. Structures then need not track changes to their components, as the components can not change but can only be replaced.

So this is not going to be the same old code for durable. And hopefully it will be much simpler and easier to understand. :-)

Bill La Forge CTO