[Malleability] Update herocache to use generics and implement BackData.

engine/common/follower/cache/distributor.go

@@ -1,38 +1,31 @@
 package cache
 
-import (
-	"github.com/onflow/flow-go/model/flow"
-	herocache "github.com/onflow/flow-go/module/mempool/herocache/backdata"
-)
-
-type OnEntityEjected func(ejectedEntity flow.Entity)
+type OnEntityEjected[V any] func(ejectedEntity V)
 
 // HeroCacheDistributor implements herocache.Tracer and allows subscribers to receive events
 // for ejected entries from cache using herocache.Tracer API.
 // This structure is NOT concurrency safe.
-type HeroCacheDistributor struct {
-	consumers []OnEntityEjected
+type HeroCacheDistributor[V any] struct {
+	consumers []OnEntityEjected[V]
 }
 
-var _ herocache.Tracer = (*HeroCacheDistributor)(nil)
-
-func NewDistributor() *HeroCacheDistributor {
-	return &HeroCacheDistributor{}
+func NewDistributor[V any]() *HeroCacheDistributor[V] {
+	return &HeroCacheDistributor[V]{}
 }
 
 // AddConsumer adds subscriber for entity ejected events.
 // Is NOT concurrency safe.
-func (d *HeroCacheDistributor) AddConsumer(consumer OnEntityEjected) {
+func (d *HeroCacheDistributor[V]) AddConsumer(consumer OnEntityEjected[V]) {
 	d.consumers = append(d.consumers, consumer)
 }
 
-func (d *HeroCacheDistributor) EntityEjectionDueToEmergency(ejectedEntity flow.Entity) {
+func (d *HeroCacheDistributor[V]) EntityEjectionDueToEmergency(ejectedEntity V) {
 	for _, consumer := range d.consumers {
 		consumer(ejectedEntity)
 	}
 }
 
-func (d *HeroCacheDistributor) EntityEjectionDueToFullCapacity(ejectedEntity flow.Entity) {
+func (d *HeroCacheDistributor[V]) EntityEjectionDueToFullCapacity(ejectedEntity V) {
 	for _, consumer := range d.consumers {
 		consumer(ejectedEntity)
 	}