core: support finality event on exec

core/blockchain.go

@@ -613,6 +613,7 @@ func (bc *BlockChain) SetFinalized(header *types.Header) {
 	if header != nil {
 		rawdb.WriteFinalizedBlockHash(bc.db, header.Hash())
 		headFinalizedBlockGauge.Update(int64(header.Number.Uint64()))
+		exex.TriggerFinalHook(header)
 	} else {
 		rawdb.WriteFinalizedBlockHash(bc.db, common.Hash{})
 		headFinalizedBlockGauge.Update(0)

core/exex/exex.go

@@ -48,4 +48,5 @@ type PluginV1 struct {
 	OnClose CloseHook // Called when the chain gets torn down within Geth
 	OnHead  HeadHook  // Called when the chain head block is updated in Geth
 	OnReorg ReorgHook // Called wnen the chain reorgs to a sidechain within Geth
+	OnFinal FinalHook // Called when the chain finalizes a block within Geth
 }

core/exex/exex/registry.go

@@ -39,6 +39,7 @@ type registry interface {
 	TriggerCloseHook()
 	TriggerHeadHook(head *types.Header)
 	TriggerReorgHook(headers []*types.Header, revert bool)
+	TriggerFinalHook(header *types.Header)
 }
 
 // Plugins returns a list of all registered plugins to generate CLI flags.
@@ -70,3 +71,8 @@ func TriggerHeadHook(head *types.Header) {
 func TriggerReorgHook(headers []*types.Header, revert bool) {
 	globalRegistry.TriggerReorgHook(headers, revert)
 }
+
+// TriggerFinalHook triggers the OnFinal hook in exex plugins.
+func TriggerFinalHook(header *types.Header) {
+	globalRegistry.TriggerFinalHook(header)
+}

core/exex/hooks.go

@@ -51,3 +51,6 @@ type HeadHook = func(head *types.Header)
 // to pass in both the reverted and applied headers at the same time, but that
 // would require chain accessorts to support sidechains, which complicate APIs.
 type ReorgHook = func(headers []*types.Header, revert bool)
+
+// FinalHook is called when the chain finalizes a past block.
+type FinalHook = func(header *types.Header)

core/exex/registry_internal.go

@@ -87,3 +87,12 @@ func (reg *registry) TriggerReorgHook(headers []*types.Header, revert bool) {
 		}
 	}
 }
+
+// TriggerFinalHook triggers the OnFinal hook in exex plugins.
+func (reg *registry) TriggerFinalHook(header *types.Header) {
+	for _, plugin := range globalRegistry.pluginsV1 {
+		if plugin.OnFinal != nil {
+			plugin.OnFinal(header)
+		}
+	}
+}