feat: support events with the same topic from different contracts (#38)

Currently, 2 events with the same topic but from different contracts are not
handled correctly, the first register handler callback is called for both
events. This commit makes the lookup key contains the both topic and contract
address to correctly find the handler callback for the event.

controller.go

@@ -387,6 +387,11 @@ func (c *Controller) processBehindBlock(listener Listener, height, latestBlockHe
 	return nil
 }
 
+type eventMapKey struct {
+	topic   common.Hash
+	address common.Address
+}
+
 func (c *Controller) processBatchLogs(listener Listener, fromHeight, toHeight uint64) uint64 {
 	var (
 		contractAddresses []common.Address
@@ -398,14 +403,19 @@ func (c *Controller) processBatchLogs(listener Listener, fromHeight, toHeight ui
 	}
 	addedContract := make(map[common.Address]struct{})
 	filteredMethods := make(map[*abi.ABI]map[string]struct{})
-	eventIds := make(map[common.Hash]string)
+	eventIds := make(map[eventMapKey]string)
 	for subscriptionName, subscription := range listener.GetSubscriptions() {
 		name := subscription.Handler.Name
 		if filteredMethods[subscription.Handler.ABI] == nil {
 			filteredMethods[subscription.Handler.ABI] = make(map[string]struct{})
 		}
 		filteredMethods[subscription.Handler.ABI][name] = struct{}{}
-		eventIds[subscription.Handler.ABI.Events[name].ID] = subscriptionName
+
+		key := eventMapKey{
+			topic:   subscription.Handler.ABI.Events[name].ID,
+			address: common.HexToAddress(subscription.To),
+		}
+		eventIds[key] = subscriptionName
 		contractAddress := common.HexToAddress(subscription.To)
 
 		if _, ok := addedContract[contractAddress]; !ok {
@@ -444,7 +454,12 @@ func (c *Controller) processBatchLogs(listener Listener, fromHeight, toHeight ui
 		for i, eventLog := range logs {
 			eventId := eventLog.Topics[0]
 			log.Trace("[Controller][processBatchLogs] processing log", "topic", eventLog.Topics[0].Hex(), "address", eventLog.Address.Hex(), "transaction", eventLog.TxHash.Hex(), "listener", listener.GetName())
-			if _, ok := eventIds[eventId]; !ok {
+			lookupKey := eventMapKey{
+				topic:   eventId,
+				address: eventLog.Address,
+			}
+
+			if _, ok := eventIds[lookupKey]; !ok {
 				continue
 			}
 			data, err := json.Marshal(eventLog)
@@ -453,7 +468,7 @@ func (c *Controller) processBatchLogs(listener Listener, fromHeight, toHeight ui
 				continue
 			}
 			processedBlocks[eventLog.BlockNumber] = struct{}{}
-			name := eventIds[eventId]
+			name := eventIds[lookupKey]
 			tx := NewEmptyTransaction(chainId, eventLog.TxHash, eventLog.Data, nil, &eventLog.Address)
 			jobs = append(jobs, listener.GetListenHandleJob(name, tx, eventId.Hex(), data))
 		}