From 45d1d222c27e489ffb333678208dd2e4880fad54 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Fri, 9 Sep 2022 11:31:17 +0200
Subject: [PATCH] core: minor refactor, send block-drop feed earlier

---
 core/blockchain.go      | 26 ++++++++------------------
 core/blockchain_test.go |  2 +-
 2 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/core/blockchain.go b/core/blockchain.go
index d6880d2d4fe9..1c764d500cee 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -2121,15 +2121,16 @@ func (bc *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 		log.Crit("Failed to delete useless indexes", "err", err)
 	}
 
-	// Send out events for deleted logs. The number of
-	// restored logs can be very high, so the events are sent in batches of
-	// size < 512.
+	// Send out events for deleted and new logs. The number of logs can be very
+	// high, so the events are sent in batches of size around 512.
+
+	// Deleted logs + blocks
 	var deletedLogs []*types.Log
 	for i := len(oldChain) - 1; i >= 0; i-- {
-		oldBlock := oldChain[i]
+		// Also send event for blocks removed from the canon chain.
+		bc.chainSideFeed.Send(ChainSideEvent{Block: oldChain[i]})
 		// Collect deleted logs for notification
-		if logs := bc.collectLogs(oldBlock.Hash(), true); len(logs) > 0 {
-			//deletedLogs = append(deletedLogs, logs)
+		if logs := bc.collectLogs(oldChain[i].Hash(), true); len(logs) > 0 {
 			deletedLogs = append(deletedLogs, logs...)
 		}
 		if len(deletedLogs) > 512 {
@@ -2140,11 +2141,7 @@ func (bc *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 	if len(deletedLogs) > 0 {
 		bc.rmLogsFeed.Send(RemovedLogsEvent{deletedLogs})
 	}
-
-	// Send events for 'reborn' logs, i.e. logs that were previously
-	// removed but now got restored in the new chain branch. The number of
-	// restored logs can be very high, so the events are sent in batches of
-	// size < 512.
+	// New logs
 	var rebirthLogs []*types.Log
 	for i := len(newChain) - 1; i >= 1; i-- {
 		// Collect reborn logs due to chain reorg
@@ -2159,13 +2156,6 @@ func (bc *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 	if len(rebirthLogs) > 0 {
 		bc.logsFeed.Send(rebirthLogs)
 	}
-
-	// Send notifications for blocks removed from the canon chain.
-	if len(oldChain) > 0 {
-		for i := len(oldChain) - 1; i >= 0; i-- {
-			bc.chainSideFeed.Send(ChainSideEvent{Block: oldChain[i]})
-		}
-	}
 	return nil
 }
 
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index b7fc26ae2086..06c43658ed9b 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -1158,7 +1158,7 @@ func TestLogRebirth(t *testing.T) {
 	blockchain.SubscribeLogsEvent(newLogCh)
 	blockchain.SubscribeRemovedLogsEvent(rmLogsCh)
 
-	// This chain contains a single log.
+	// This chain contains 10 logs.
 	genDb, chain, _ := GenerateChainWithGenesis(gspec, engine, 3, func(i int, gen *BlockGen) {
 		if i < 2 {
 			for ii := 0; ii < 5; ii++ {