From 2aa49b926b85e75cb62f7657fd35824352fe5a40 Mon Sep 17 00:00:00 2001
From: devopsbo3 <69951731+devopsbo3@users.noreply.github.com>
Date: Fri, 10 Nov 2023 12:27:53 -0600
Subject: [PATCH] Revert "trie: reduce allocs in recHash (#27770)"

This reverts commit 06434771a13c23b6c9d3295336ce557a79b4055a.
---
 trie/encoding.go      |  7 ++++---
 trie/encoding_test.go | 13 ++++---------
 trie/stacktrie.go     |  4 ++--
 3 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/trie/encoding.go b/trie/encoding.go
index 3284d3f8f0..8ee0022ef3 100644
--- a/trie/encoding.go
+++ b/trie/encoding.go
@@ -51,8 +51,9 @@ func hexToCompact(hex []byte) []byte {
 	return buf
 }
 
-// hexToCompactInPlace places the compact key in input buffer, returning the compacted key.
-func hexToCompactInPlace(hex []byte) []byte {
+// hexToCompactInPlace places the compact key in input buffer, returning the length
+// needed for the representation
+func hexToCompactInPlace(hex []byte) int {
 	var (
 		hexLen    = len(hex) // length of the hex input
 		firstByte = byte(0)
@@ -76,7 +77,7 @@ func hexToCompactInPlace(hex []byte) []byte {
 		hex[bi] = hex[ni]<<4 | hex[ni+1]
 	}
 	hex[0] = firstByte
-	return hex[:binLen]
+	return binLen
 }
 
 func compactToHex(compact []byte) []byte {
diff --git a/trie/encoding_test.go b/trie/encoding_test.go
index ac50b5d025..d16d25c359 100644
--- a/trie/encoding_test.go
+++ b/trie/encoding_test.go
@@ -86,7 +86,8 @@ func TestHexToCompactInPlace(t *testing.T) {
 	} {
 		hexBytes, _ := hex.DecodeString(key)
 		exp := hexToCompact(hexBytes)
-		got := hexToCompactInPlace(hexBytes)
+		sz := hexToCompactInPlace(hexBytes)
+		got := hexBytes[:sz]
 		if !bytes.Equal(exp, got) {
 			t.Fatalf("test %d: encoding err\ninp %v\ngot %x\nexp %x\n", i, key, got, exp)
 		}
@@ -101,7 +102,8 @@ func TestHexToCompactInPlaceRandom(t *testing.T) {
 		hexBytes := keybytesToHex(key)
 		hexOrig := []byte(string(hexBytes))
 		exp := hexToCompact(hexBytes)
-		got := hexToCompactInPlace(hexBytes)
+		sz := hexToCompactInPlace(hexBytes)
+		got := hexBytes[:sz]
 
 		if !bytes.Equal(exp, got) {
 			t.Fatalf("encoding err \ncpt %x\nhex %x\ngot %x\nexp %x\n",
@@ -117,13 +119,6 @@ func BenchmarkHexToCompact(b *testing.B) {
 	}
 }
 
-func BenchmarkHexToCompactInPlace(b *testing.B) {
-	testBytes := []byte{0, 15, 1, 12, 11, 8, 16 /*term*/}
-	for i := 0; i < b.N; i++ {
-		hexToCompactInPlace(testBytes)
-	}
-}
-
 func BenchmarkCompactToHex(b *testing.B) {
 	testBytes := []byte{0, 15, 1, 12, 11, 8, 16 /*term*/}
 	for i := 0; i < b.N; i++ {
diff --git a/trie/stacktrie.go b/trie/stacktrie.go
index 0d65ee75e0..ee1ce28291 100644
--- a/trie/stacktrie.go
+++ b/trie/stacktrie.go
@@ -444,7 +444,7 @@ func (st *StackTrie) hashRec(hasher *hasher, path []byte) {
 	case extNode:
 		st.children[0].hashRec(hasher, append(path, st.key...))
 
-		n := shortNode{Key: hexToCompactInPlace(st.key)}
+		n := shortNode{Key: hexToCompact(st.key)}
 		if len(st.children[0].val) < 32 {
 			n.Val = rawNode(st.children[0].val)
 		} else {
@@ -460,7 +460,7 @@ func (st *StackTrie) hashRec(hasher *hasher, path []byte) {
 
 	case leafNode:
 		st.key = append(st.key, byte(16))
-		n := shortNode{Key: hexToCompactInPlace(st.key), Val: valueNode(st.val)}
+		n := shortNode{Key: hexToCompact(st.key), Val: valueNode(st.val)}
 
 		n.encode(hasher.encbuf)
 		encodedNode = hasher.encodedBytes()