swarm/network/stream: don't hardcode price

swarm/network/stream/stream.go

@@ -781,25 +781,37 @@ func (sp *StreamerPrices) Price(msg interface{}) *protocols.Price {
 	return sp.priceMatrix[t]
 }
 
+// Instead of hardcoding the price, get it
+// through a function - it could be quite complex in the future
+func (sp *StreamerPrices) getRetrieveRequestMsgPrice() uint64 {
+	return uint64(1)
+}
+
+// Instead of hardcoding the price, get it
+// through a function - it could be quite complex in the future
+func (sp *StreamerPrices) getChunkDeliveryMsgRetrievalPrice() uint64 {
+	return uint64(1)
+}
+
 // createPriceOracle sets up a matrix which can be queried to get
 // the price for a message via the Price method
 func (r *Registry) createPriceOracle() {
-	po := &StreamerPrices{
+	sp := &StreamerPrices{
 		registry: r,
 	}
-	po.priceMatrix = map[reflect.Type]*protocols.Price{
+	sp.priceMatrix = map[reflect.Type]*protocols.Price{
 		reflect.TypeOf(ChunkDeliveryMsgRetrieval{}): {
-			Value:   uint64(1), // arbitrary price for now
+			Value:   sp.getChunkDeliveryMsgRetrievalPrice(), // arbitrary price for now
 			PerByte: true,
 			Payer:   protocols.Receiver,
 		},
 		reflect.TypeOf(RetrieveRequestMsg{}): {
-			Value:   uint64(1), // arbitrary price for now
+			Value:   sp.getRetrieveRequestMsgPrice(), // arbitrary price for now
 			PerByte: false,
 			Payer:   protocols.Sender,
 		},
 	}
-	r.prices = po
+	r.prices = sp
 }
 
 func (r *Registry) Protocols() []p2p.Protocol {

swarm/network/stream/streamer_test.go

@@ -922,9 +922,8 @@ func TestMaxPeerServersWithoutUnsubscribe(t *testing.T) {
 	}
 }
 
-func TestRetrievalIsBilled(t *testing.T) {
-}
-
+//TestHasPriceImplementation is to check that the Registry has a
+//`Price` interface implementation
 func TestHasPriceImplementation(t *testing.T) {
 	_, r, _, teardown, err := newStreamerTester(t, &RegistryOptions{
 		Retrieval: RetrievalDisabled,
@@ -939,13 +938,17 @@ func TestHasPriceImplementation(t *testing.T) {
 		t.Fatal("No prices implementation available for the stream protocol")
 	}
 
-	price := r.prices.Price(&ChunkDeliveryMsgRetrieval{})
-	if price == nil || price.Value == 0 {
+	pricesInstance, ok := r.prices.(*StreamerPrices)
+	if !ok {
+		t.Fatal("`Registry` does not have the expected Prices instance")
+	}
+	price := pricesInstance.Price(&ChunkDeliveryMsgRetrieval{})
+	if price == nil || price.Value == 0 && price.Value != pricesInstance.getChunkDeliveryMsgRetrievalPrice() {
 		t.Fatal("No prices set for chunk delivery msg")
 	}
 
-	price = r.prices.Price(&RetrieveRequestMsg{})
-	if price == nil || price.Value == 0 {
+	price = pricesInstance.Price(&RetrieveRequestMsg{})
+	if price == nil || price.Value == 0 && price.Value != pricesInstance.getRetrieveRequestMsgPrice() {
 		t.Fatal("No prices set for chunk delivery msg")
 	}
 }