diff --git a/docs/architecture/adr-037-peer-behaviour.md b/docs/architecture/adr-039-peer-behaviour.md similarity index 57% rename from docs/architecture/adr-037-peer-behaviour.md rename to docs/architecture/adr-039-peer-behaviour.md index 36b024482..4ad051a35 100644 --- a/docs/architecture/adr-037-peer-behaviour.md +++ b/docs/architecture/adr-039-peer-behaviour.md @@ -1,7 +1,8 @@ -# ADR 037: Peer Behaviour Interface +# ADR 039: Peer Behaviour Interface ## Changelog * 07-03-2019: Initial draft +* 14-03-2019: Updates from feedback ## Context @@ -19,36 +20,46 @@ and ties up the reactors in a larger dependency graph when testing. Introduce a `PeerBehaviour` interface and concrete implementations which provide methods for reactors to signal peer behaviour without direct -coupling `p2p.Switch`. Introduce a ErrPeer to provide -concrete reasons for stopping peers. +coupling `p2p.Switch`. Introduce a ErrorBehaviourPeer to provide +concrete reasons for stopping peers. Introduce GoodBehaviourPeer to provide +concrete ways in which a peer contributes. ### Implementation Changes PeerBehaviour then becomes an interface for signaling peer errors as well as for marking peers as `good`. -XXX: It might be better to pass p2p.ID instead of the whole peer but as -a first draft maintain the underlying implementation as much as -possible. - ```go type PeerBehaviour interface { - Errored(peer Peer, reason ErrPeer) - MarkPeerAsGood(peer Peer) + Behaved(peer Peer, reason GoodBehaviourPeer) + Errored(peer Peer, reason ErrorBehaviourPeer) } ``` Instead of signaling peers to stop with arbitrary reasons: `reason interface{}` -We introduce a concrete error type ErrPeer: +We introduce a concrete error type ErrorBehaviourPeer: ```go -type ErrPeer int +type ErrorBehaviourPeer int const ( - ErrPeerUnknown = iota - ErrPeerBadMessage - ErrPeerMessageOutofOrder + ErrorBehaviourUnknown = iota + ErrorBehaviourBadMessage + ErrorBehaviourMessageOutofOrder + ... +) +``` + +To provide additional information on the ways a peer contributed, we introduce +the GoodBehaviourPeer type. + +```go +type GoodBehaviourPeer int + +const ( + GoodBehaviourVote = iota + GoodBehaviourBlockPart ... ) ``` @@ -60,11 +71,11 @@ type SwitchedPeerBehaviour struct { sw *Switch } -func (spb *SwitchedPeerBehaviour) Errored(peer Peer, reason ErrPeer) { +func (spb *SwitchedPeerBehaviour) Errored(peer Peer, reason ErrorBehaviourPeer) { spb.sw.StopPeerForError(peer, reason) } -func (spb *SwitchedPeerBehaviour) MarkPeerAsGood(peer Peer) { +func (spb *SwitchedPeerBehaviour) Behaved(peer Peer, reason GoodBehaviourPeer) { spb.sw.MarkPeerAsGood(peer) } @@ -75,51 +86,54 @@ func NewSwitchedPeerBehaviour(sw *Switch) *SwitchedPeerBehaviour { } ``` -Reactors, which are often difficult to unit test[2](#references). could use an implementation which exposes the signals produced by the reactor in +Reactors, which are often difficult to unit test[2](#references) could use an implementation which exposes the signals produced by the reactor in manufactured scenarios: ```go -type PeerErrors map[Peer][]ErrPeer -type GoodPeers map[Peer]bool +type ErrorBehaviours map[Peer][]ErrorBehaviourPeer +type GoodBehaviours map[Peer][]GoodBehaviourPeer type StorePeerBehaviour struct { - pe PeerErrors - gp GoodPeers + eb ErrorBehaviours + gb GoodBehaviours } func NewStorePeerBehaviour() *StorePeerBehaviour{ return &StorePeerBehaviour{ - pe: make(PeerErrors), - gp: GoodPeers{}, + eb: make(ErrorBehaviours), + gb: make(GoodBehaviours), } } -func (spb StorePeerBehaviour) Errored(peer Peer, reason ErrPeer) { - if _, ok := spb.pe[peer]; !ok { - spb.pe[peer] = []ErrPeer{reason} +func (spb StorePeerBehaviour) Errored(peer Peer, reason ErrorBehaviourPeer) { + if _, ok := spb.eb[peer]; !ok { + spb.eb[peer] = []ErrorBehaviours{reason} } else { - spb.pe[peer] = append(spb.pe[peer], reason) + spb.eb[peer] = append(spb.eb[peer], reason) } } -func (mpb *StorePeerBehaviour) GetPeerErrors() PeerErrors { - return mpb.pe +func (mpb *StorePeerBehaviour) GetErrored() ErrorBehaviours { + return mpb.eb } -func (spb *StorePeerBehaviour) MarkPeerAsGood(peer Peer) { - if _, ok := spb.gp[peer]; !ok { - spb.gp[peer] = true + +func (spb StorePeerBehaviour) Behaved(peer Peer, reason GoodBehaviourPeer) { + if _, ok := spb.gb[peer]; !ok { + spb.gb[peer] = []GoodBehaviourPeer{reason} + } else { + spb.gb[peer] = append(spb.gb[peer], reason) } } -func (spb *StorePeerBehaviour) GetGoodPeers() GoodPeers { - return spb.gp +func (spb *StorePeerBehaviour) GetBehaved() GoodBehaviours { + return spb.gb } ``` ## Status -Proposed +Accepted ## Consequences