core/tracing: add hook for reverted out blocks

core/blockchain.go

@@ -2375,6 +2375,10 @@ func (bc *BlockChain) reorg(oldHead *types.Header, newHead *types.Block) error {
 	if len(rebirthLogs) > 0 {
 		bc.logsFeed.Send(rebirthLogs)
 	}
+
+	if bc.logger != nil && bc.logger.OnReorg != nil {
+		bc.logger.OnReorg(oldChain)
+	}
 	return nil
 }
 

core/tracing/hooks.go

@@ -134,6 +134,9 @@ type (
 	// GenesisBlockHook is called when the genesis block is being processed.
 	GenesisBlockHook = func(genesis *types.Block, alloc types.GenesisAlloc)
 
+	// ReorgHook is called when a segment of the chain is reverted.
+	ReorgHook = func(reverted []*types.Block)
+
 	// OnSystemCallStartHook is called when a system call is about to be executed. Today,
 	// this hook is invoked when the EIP-4788 system call is about to be executed to set the
 	// beacon block root.
@@ -186,6 +189,7 @@ type Hooks struct {
 	OnBlockEnd        BlockEndHook
 	OnSkippedBlock    SkippedBlockHook
 	OnGenesisBlock    GenesisBlockHook
+	OnReorg           ReorgHook
 	OnSystemCallStart OnSystemCallStartHook
 	OnSystemCallEnd   OnSystemCallEndHook
 	// State events