Move (core/)types.rlpHash -> (crypto/)hash.FromRLP

This is because one of its consumers (types.Header) will move out of the
types package.

core/types/block.go

@@ -31,8 +31,8 @@ import (
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/rs/zerolog"
-	"golang.org/x/crypto/sha3"
 
+	"github.com/harmony-one/harmony/crypto/hash"
 	"github.com/harmony-one/harmony/internal/utils"
 	"github.com/harmony-one/harmony/shard"
 )
@@ -113,7 +113,7 @@ type headerMarshaling struct {
 // Hash returns the block hash of the header, which is simply the keccak256 hash of its
 // RLP encoding.
 func (h *Header) Hash() common.Hash {
-	return RLPHash(h)
+	return hash.FromRLP(h)
 }
 
 // Size returns the approximate memory used by all internal contents. It is used
@@ -145,14 +145,6 @@ func (h *Header) GetShardState() (shard.ShardState, error) {
 	return shardState, nil
 }
 
-// RLPHash hashes the RLP representation of the given object.
-func RLPHash(x interface{}) (h common.Hash) {
-	hw := sha3.NewLegacyKeccak256()
-	rlp.Encode(hw, x)
-	hw.Sum(h[:0])
-	return h
-}
-
 // Body is a simple (mutable, non-safe) data container for storing and moving
 // a block's data contents (transactions and uncles) together.
 type Body struct {
@@ -454,7 +446,7 @@ func (c *writeCounter) Write(b []byte) (int, error) {
 
 // CalcUncleHash returns rlp hash of uncles.
 func CalcUncleHash(uncles []*Header) common.Hash {
-	return RLPHash(uncles)
+	return hash.FromRLP(uncles)
 }
 
 // WithSeal returns a new block with the data from b but the header replaced with

core/types/transaction.go

@@ -28,6 +28,8 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/rlp"
+
+	"github.com/harmony-one/harmony/crypto/hash"
 	common2 "github.com/harmony-one/harmony/internal/common"
 )
 
@@ -292,7 +294,7 @@ func (tx *Transaction) Hash() common.Hash {
 	if hash := tx.hash.Load(); hash != nil {
 		return hash.(common.Hash)
 	}
-	v := RLPHash(tx)
+	v := hash.FromRLP(tx)
 	tx.hash.Store(v)
 	return v
 }

core/types/transaction_signing.go

@@ -24,6 +24,8 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+
+	"github.com/harmony-one/harmony/crypto/hash"
 	"github.com/harmony-one/harmony/internal/params"
 )
 
@@ -157,7 +159,7 @@ func (s EIP155Signer) SignatureValues(tx *Transaction, sig []byte) (R, S, V *big
 // Hash returns the hash to be signed by the sender.
 // It does not uniquely identify the transaction.
 func (s EIP155Signer) Hash(tx *Transaction) common.Hash {
-	return RLPHash([]interface{}{
+	return hash.FromRLP([]interface{}{
 		tx.data.AccountNonce,
 		tx.data.Price,
 		tx.data.GasLimit,
@@ -215,7 +217,7 @@ func (fs FrontierSigner) SignatureValues(tx *Transaction, sig []byte) (r, s, v *
 // Hash returns the hash to be signed by the sender.
 // It does not uniquely identify the transaction.
 func (fs FrontierSigner) Hash(tx *Transaction) common.Hash {
-	return RLPHash([]interface{}{
+	return hash.FromRLP([]interface{}{
 		tx.data.AccountNonce,
 		tx.data.Price,
 		tx.data.GasLimit,

crypto/hash/rlp.go

@@ -0,0 +1,15 @@
+package hash
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/rlp"
+	"golang.org/x/crypto/sha3"
+)
+
+// FromRLP hashes the RLP representation of the given object.
+func FromRLP(x interface{}) (h common.Hash) {
+	hw := sha3.NewLegacyKeccak256()
+	rlp.Encode(hw, x)
+	hw.Sum(h[:0])
+	return h
+}