From 9883354c1df04765890936358c061e5a6b57030e Mon Sep 17 00:00:00 2001
From: Evolution404 <615598813@qq.com>
Date: Tue, 1 Jun 2021 19:20:21 +0800
Subject: [PATCH 1/3] trie/trie.go improve the delete performance

---
 trie/trie.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/trie/trie.go b/trie/trie.go
index 7ed235fa8ac..c0f4ae5f91f 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -405,6 +405,10 @@ func (t *Trie) delete(n node, prefix, key []byte) (bool, node, error) {
 		n.flags = t.newFlag()
 		n.Children[key[0]] = nn
 
+		if nn != nil {
+			// n still contains at least two values and cannot be reduced.
+			return true, n, nil
+		}
 		// Check how many non-nil entries are left after deleting and
 		// reduce the full node to a short node if only one entry is
 		// left. Since n must've contained at least two children

From 1dbb8f6118c3f61157de6b0596aec0cadc36251f Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Fri, 18 Jun 2021 14:30:58 +0200
Subject: [PATCH 2/3] trie: improve comment about skipping reduction in delete

---
 trie/trie.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/trie/trie.go b/trie/trie.go
index c0f4ae5f91f..d3c852d6a0f 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -405,10 +405,14 @@ func (t *Trie) delete(n node, prefix, key []byte) (bool, node, error) {
 		n.flags = t.newFlag()
 		n.Children[key[0]] = nn
 
+		// Because n is a full node, it must've contained at least two children
+		// before the delete operation. If the new child value is non-nil, n still
+		// has at least two children after the deletion, and cannot be reduced to
+		// a short node.
 		if nn != nil {
-			// n still contains at least two values and cannot be reduced.
 			return true, n, nil
-		}
+		}		
+		// Reduction:
 		// Check how many non-nil entries are left after deleting and
 		// reduce the full node to a short node if only one entry is
 		// left. Since n must've contained at least two children

From 69ff42e8c90d6835d68b3e9d08f300101c252a39 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Fri, 18 Jun 2021 14:54:11 +0200
Subject: [PATCH 3/3] trie: whitespace

---
 trie/trie.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/trie/trie.go b/trie/trie.go
index d3c852d6a0f..e492a532cb2 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -411,7 +411,7 @@ func (t *Trie) delete(n node, prefix, key []byte) (bool, node, error) {
 		// a short node.
 		if nn != nil {
 			return true, n, nil
-		}		
+		}
 		// Reduction:
 		// Check how many non-nil entries are left after deleting and
 		// reduce the full node to a short node if only one entry is