Want and have interactions

[ghost]

There are lots of little details and edge cases with Want and Have messages.

For example:

1. You have a piece that your peer wants, and you tell them you have it
2. They tell you they no longer want it
3. You delete the piece
4. They tell you they want it again

When do you tell the peer that you no longer have the piece? What assumptions can your peer make about whether you have the piece? When do they know it’s ok to send a request for the piece?

Figure out how these details work and get more rigorous in the explanation. Maybe try a state machine diagram for this one.