relay policies as interfaces, SimplePolicy as the most basic implementation.

relaypool.go

@@ -34,9 +34,9 @@ type RelayPool struct {
 	Notices chan *NoticeMessage
 }
 
-type RelayPoolPolicy struct {
-	SimplePolicy
-	ReadSpecific map[string]SimplePolicy
+type RelayPoolPolicy interface {
+	ShouldRead(EventFilters) bool
+	ShouldWrite(*Event) bool
 }
 
 type SimplePolicy struct {
@@ -44,6 +44,14 @@ type SimplePolicy struct {
 	Write bool
 }
 
+func (s SimplePolicy) ShouldRead(_ EventFilters) bool {
+	return s.Read
+}
+
+func (s SimplePolicy) ShouldWrite(_ *Event) bool {
+	return s.Write
+}
+
 type NoticeMessage struct {
 	Message string
 	Relay   string
@@ -62,9 +70,9 @@ func NewRelayPool() *RelayPool {
 
 // Add adds a new relay to the pool, if policy is nil, it will be a simple
 // read+write policy.
-func (r *RelayPool) Add(url string, policy *RelayPoolPolicy) error {
+func (r *RelayPool) Add(url string, policy RelayPoolPolicy) error {
 	if policy == nil {
-		policy = &RelayPoolPolicy{SimplePolicy: SimplePolicy{Read: true, Write: true}}
+		policy = SimplePolicy{Read: true, Write: true}
 	}
 
 	nm := NormalizeURL(url)
@@ -77,7 +85,7 @@ func (r *RelayPool) Add(url string, policy *RelayPoolPolicy) error {
 		return fmt.Errorf("error opening websocket to '%s': %w", nm, err)
 	}
 
-	r.Relays[nm] = *policy
+	r.Relays[nm] = policy
 	r.websockets[nm] = conn
 
 	for _, sub := range r.subscriptions {
@@ -177,7 +185,7 @@ func (r *RelayPool) Sub(filters EventFilters) *Subscription {
 	subscription.channel = hex.EncodeToString(random)
 	subscription.relays = make(map[string]*websocket.Conn)
 	for relay, policy := range r.Relays {
-		if policy.Read {
+		if policy.ShouldRead(filters) {
 			ws := r.websockets[relay]
 			subscription.relays[relay] = ws
 		}
@@ -213,6 +221,10 @@ func (r *RelayPool) PublishEvent(evt *Event) (*Event, chan PublishStatus, error)
 	}
 
 	for relay, conn := range r.websockets {
+		if !r.Relays[relay].ShouldWrite(evt) {
+			continue
+		}
+
 		go func(relay string, conn *websocket.Conn) {
 			err := conn.WriteJSON([]interface{}{"EVENT", evt})
 			if err != nil {