How does the decision engine currently work?

[kbala444]

If the engine decides that a peer isn't worth sending to, would it remove that peer's requests from the peer request queue? Or would I make a new task comparator in peer_request_queue.go that pushes requests from bad peers to the end of the queue?

And is there currently some mechanism in place for peers to control which providers to connect to/download blocks from? If not, could bitswap filter the list of all possible providers in connectToProviders() using the decision engine?

Also @jbenet mentioned that there was some existing code that made decisions based on ledger information, if it isn't too much trouble, could you guys point me to where it is? I can't seem to find it.

Thanks!

[whyrusleeping]

if you want to decide that a certain peer isnt worth sending to, you would have to change the logic in peer_request_queue.go in the Pop() method. We currently dont actually have a way to say 'i'm not going to send to this peer', we can say 'prioritize this peer as the last in line' by using a custom comparitor in the peer_request_queue.

There isnt any existing code for making decisions based on ledger information, we used to have it, but it got dropped during a refactor for one reason or another.