From b40a9b85ad10b3f18c00702acb045e6687d1a050 Mon Sep 17 00:00:00 2001
From: Gary Rong <garyrong0905@gmail.com>
Date: Wed, 10 Dec 2025 14:39:27 +0800
Subject: [PATCH] core/rawdb: simplify the size counting

---
 core/rawdb/freezer_memory.go | 29 +++++++++--------------------
 1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/core/rawdb/freezer_memory.go b/core/rawdb/freezer_memory.go
index 32bb680f36..a0d308f896 100644
--- a/core/rawdb/freezer_memory.go
+++ b/core/rawdb/freezer_memory.go
@@ -91,15 +91,14 @@ func (t *memoryTable) truncateHead(items uint64) error {
 	if items < t.offset {
 		return errors.New("truncation below tail")
 	}
-	removeFrom := items - t.offset
-	for i := int(removeFrom); i < len(t.data); i++ {
+	for i := int(items - t.offset); i < len(t.data); i++ {
 		if t.size > uint64(len(t.data[i])) {
 			t.size -= uint64(len(t.data[i]))
 		} else {
 			t.size = 0
 		}
 	}
-	t.data = t.data[:removeFrom]
+	t.data = t.data[:items-t.offset]
 	t.items = items
 	return nil
 }
@@ -116,25 +115,15 @@ func (t *memoryTable) truncateTail(items uint64) error {
 	if t.items < items {
 		return errors.New("truncation above head")
 	}
-	drop := items - t.offset
-	var removed uint64
-	for i := uint64(0); i < drop; i++ {
-		removed += uint64(len(t.data[i]))
-	}
-	newLen := uint64(len(t.data)) - drop
-	if newLen == 0 {
-		t.data = nil
-	} else {
-		newData := make([][]byte, newLen)
-		copy(newData, t.data[drop:])
-		t.data = newData
+	for i := uint64(0); i < items-t.offset; i++ {
+		if t.size > uint64(len(t.data[i])) {
+			t.size -= uint64(len(t.data[i]))
+		} else {
+			t.size = 0
+		}
 	}
+	t.data = t.data[items-t.offset:]
 	t.offset = items
-	if removed >= t.size {
-		t.size = 0
-	} else {
-		t.size -= removed
-	}
 	return nil
 }