crypto: refactor deduplicate hashing logic

crypto/keccak.go

@@ -39,25 +39,23 @@ var hasherPool = sync.Pool{
 // Keccak256 calculates and returns the Keccak256 hash of the input data.
 func Keccak256(data ...[]byte) []byte {
 	b := make([]byte, 32)
-	d := hasherPool.Get().(KeccakState)
-	d.Reset()
-	for _, b := range data {
-		d.Write(b)
-	}
-	d.Read(b)
-	hasherPool.Put(d)
+	hashInto(b, data...)
 	return b
 }
 
 // Keccak256Hash calculates and returns the Keccak256 hash of the input data,
 // converting it to an internal Hash data structure.
 func Keccak256Hash(data ...[]byte) (h common.Hash) {
+	hashInto(h[:], data...)
+	return h
+}
+
+func hashInto(out []byte, data ...[]byte) {
 	d := hasherPool.Get().(KeccakState)
+	defer hasherPool.Put(d)
 	d.Reset()
 	for _, b := range data {
 		d.Write(b)
 	}
-	d.Read(h[:])
-	hasherPool.Put(d)
-	return h
+	d.Read(out)
 }