Allow parallel block processing

Signed-off-by: Alexandros Filios <alexandros.filios@ibm.com>

Author: alexandrosfilios

platform/fabric/core/generic/finality/listenermanager.go

@@ -45,10 +45,11 @@ type ListenerManager[T TxInfo] interface {
 type TxInfoCallback[T TxInfo] func(T) error
 
 type DeliveryListenerManagerConfig struct {
-	MapperParallelism int
-	ListenerTimeout   time.Duration
-	LRUSize           int
-	LRUBuffer         int
+	MapperParallelism       int
+	BlockProcessParallelism int
+	ListenerTimeout         time.Duration
+	LRUSize                 int
+	LRUBuffer               int
 }
 
 func NewListenerManager[T TxInfo](config DeliveryListenerManagerConfig, delivery *fabric.Delivery, tracer trace.Tracer, mapper TxInfoMapper[T]) (*listenerManager[T], error) {
@@ -71,12 +72,13 @@ func NewListenerManager[T TxInfo](config DeliveryListenerManagerConfig, delivery
 		txInfos = cache.NewMapCache[driver2.TxID, T]()
 	}
 	flm := &listenerManager[T]{
-		mapper:            &parallelBlockMapper[T]{cap: max(config.MapperParallelism, 1), mapper: mapper},
-		tracer:            tracer,
-		listeners:         listeners,
-		txInfos:           txInfos,
-		ignoreBlockErrors: true,
-		delivery:          delivery,
+		mapper:                     &parallelBlockMapper[T]{cap: max(config.MapperParallelism, 1), mapper: mapper},
+		tracer:                     tracer,
+		listeners:                  listeners,
+		txInfos:                    txInfos,
+		ignoreBlockErrors:          true,
+		blockProcessingParallelism: config.BlockProcessParallelism,
+		delivery:                   delivery,
 	}
 	logger.Infof("Starting delivery service...")
 	go flm.start()
@@ -110,22 +112,40 @@ func fetchTxs[T TxInfo](evicted map[driver2.TxID][]ListenerEntry[T], mapper TxIn
 
 func (m *listenerManager[T]) start() {
 	// In case the delivery service fails, it will try to reconnect automatically.
-	err := m.delivery.ScanBlock(context.Background(), func(ctx context.Context, block *common.Block) (bool, error) {
-		err := m.onBlock(ctx, block)
-		return !m.ignoreBlockErrors && err != nil, err
-	})
+	err := m.delivery.ScanBlock(context.Background(), m.newBlockCallback())
 	logger.Errorf("failed running delivery: %v", err)
 }
 
+func (m *listenerManager[T]) newBlockCallback() fabric.BlockCallback {
+	if m.blockProcessingParallelism <= 1 {
+		return func(ctx context.Context, block *common.Block) (bool, error) {
+			err := m.onBlock(ctx, block)
+			return !m.ignoreBlockErrors && err != nil, err
+		}
+	}
+	eg := errgroup.Group{}
+	eg.SetLimit(m.blockProcessingParallelism)
+	return func(ctx context.Context, block *common.Block) (bool, error) {
+		eg.Go(func() error {
+			if err := m.onBlock(ctx, block); err != nil {
+				logger.Warnf("Mapping block [%d] errored: %v", block.Header.Number, err)
+			}
+			return nil
+		})
+		return false, nil
+	}
+}
+
 type listenerManager[T TxInfo] struct {
 	tracer trace.Tracer
 	mapper *parallelBlockMapper[T]
 
-	mu                sync.RWMutex
-	listeners         cache.Map[driver2.TxID, []ListenerEntry[T]]
-	txInfos           cache.Map[driver2.TxID, T]
-	delivery          *fabric.Delivery
-	ignoreBlockErrors bool
+	mu                         sync.RWMutex
+	listeners                  cache.Map[driver2.TxID, []ListenerEntry[T]]
+	txInfos                    cache.Map[driver2.TxID, T]
+	delivery                   *fabric.Delivery
+	blockProcessingParallelism int
+	ignoreBlockErrors          bool
 }
 
 func (m *listenerManager[T]) onBlock(ctx context.Context, block *common.Block) error {