From 07e7e8f2e04199cdae1477d5160320000f67ce4f Mon Sep 17 00:00:00 2001
From: Sahil-4555 <sahilsojitra4555@gmail.com>
Date: Tue, 16 Dec 2025 11:07:37 +0530
Subject: [PATCH] core/rawdb: refactor headerKey to prealloc + copy

---
 core/rawdb/schema.go | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/core/rawdb/schema.go b/core/rawdb/schema.go
index d9140c5fd6..a1e07a78a2 100644
--- a/core/rawdb/schema.go
+++ b/core/rawdb/schema.go
@@ -191,7 +191,15 @@ func headerKeyPrefix(number uint64) []byte {
 
 // headerKey = headerPrefix + num (uint64 big endian) + hash
 func headerKey(number uint64, hash common.Hash) []byte {
-	return append(append(headerPrefix, encodeBlockNumber(number)...), hash.Bytes()...)
+	totalLen := len(headerPrefix) + 8 + common.HashLength
+	out := make([]byte, totalLen)
+
+	off := 0
+	off += copy(out[off:], headerPrefix)
+	off += copy(out[off:], encodeBlockNumber(number))
+	copy(out[off:], hash.Bytes())
+
+	return out
 }
 
 // headerHashKey = headerPrefix + num (uint64 big endian) + headerHashSuffix