core/state: value diff tracking in StateDB (#27349)

This change makes the StateDB track the state key value diff of a block transition.
We already tracked current account and storage values for the purpose of updating
the state snapshot. With this PR, we now also track the original (pre-transition) values
of accounts and storage slots.

light/postprocess.go

@@ -220,7 +220,7 @@ func (c *ChtIndexerBackend) Commit() error {
 	}
 	// Commit trie changes into trie database in case it's not nil.
 	if nodes != nil {
-		if err := c.triedb.Update(root, c.originRoot, trienode.NewWithNodeSet(nodes)); err != nil {
+		if err := c.triedb.Update(root, c.originRoot, trienode.NewWithNodeSet(nodes), nil); err != nil {
 			return err
 		}
 		if err := c.triedb.Commit(root, false); err != nil {
@@ -473,7 +473,7 @@ func (b *BloomTrieIndexerBackend) Commit() error {
 	}
 	// Commit trie changes into trie database in case it's not nil.
 	if nodes != nil {
-		if err := b.triedb.Update(root, b.originRoot, trienode.NewWithNodeSet(nodes)); err != nil {
+		if err := b.triedb.Update(root, b.originRoot, trienode.NewWithNodeSet(nodes), nil); err != nil {
 			return err
 		}
 		if err := b.triedb.Commit(root, false); err != nil {

light/trie.go

@@ -121,19 +121,22 @@ func (t *odrTrie) GetStorage(_ common.Address, key []byte) ([]byte, error) {
 }
 
 func (t *odrTrie) GetAccount(address common.Address) (*types.StateAccount, error) {
-	var res types.StateAccount
-	key := crypto.Keccak256(address.Bytes())
+	var (
+		enc []byte
+		key = crypto.Keccak256(address.Bytes())
+	)
 	err := t.do(key, func() (err error) {
-		value, err := t.trie.Get(key)
-		if err != nil {
-			return err
-		}
-		if value == nil {
-			return nil
-		}
-		return rlp.DecodeBytes(value, &res)
+		enc, err = t.trie.Get(key)
+		return err
 	})
-	return &res, err
+	if err != nil || len(enc) == 0 {
+		return nil, err
+	}
+	acct := new(types.StateAccount)
+	if err := rlp.DecodeBytes(enc, acct); err != nil {
+		return nil, err
+	}
+	return acct, nil
 }
 
 func (t *odrTrie) UpdateAccount(address common.Address, acc *types.StateAccount) error {