fix(relayer): fix scanning blocks twice (#14047)

packages/relayer/indexer/detect_and_handle_reorg.go

@@ -19,7 +19,6 @@ func (svc *Service) detectAndHandleReorg(ctx context.Context, eventType string,
 	}
 
 	// reorg detected
-
 	log.Infof("reorg detected for msgHash %v and eventType %v", msgHash, eventType)
 
 	err = svc.eventRepo.Delete(ctx, e.ID)

packages/relayer/indexer/filter_then_subscribe.go

@@ -2,6 +2,7 @@ package indexer
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/pkg/errors"
@@ -63,9 +64,17 @@ func (svc *Service) FilterThenSubscribe(
 			end = header.Number.Uint64()
 		}
 
+		// filter exclusive of the end block.
+		// we use "end" as the next starting point of the batch, and
+		// process up to end - 1 for this batch.
+		filterEnd := end - 1
+
+		fmt.Printf("block batch from %v to %v", i, filterEnd)
+		fmt.Println()
+
 		filterOpts := &bind.FilterOpts{
 			Start:   svc.processingBlockHeight,
-			End:     &end,
+			End:     &filterEnd,
 			Context: ctx,
 		}
 
@@ -88,6 +97,8 @@ func (svc *Service) FilterThenSubscribe(
 		}
 
 		if !messageSentEvents.Next() || messageSentEvents.Event == nil {
+			// use "end" not "filterEnd" here, because it will be used as the start
+			// of the next batch.
 			if err := svc.handleNoEventsInBatch(ctx, chainID, int64(end)); err != nil {
 				return errors.Wrap(err, "svc.handleNoEventsInBatch")
 			}