trie/pathdb: decode verkle node in loadLayers

[gballet]

In loadLayers, the root is computed by hashing (keccak) the node. This is not going to work for a verkle node, so make sure the correct root node derivation is used.

[holiman]

I think the "default" code path should be non-verkle. So instead of having a if !isVerkle special case, make it if isVerkle into the special case

Suggested change

	if !isVerkle {
	if len(blob) == 0 {
	return types.EmptyRootHash, nil
	}
	return crypto.Keccak256Hash(blob), nil
	}
	// Compute the node hash in verkle tree manner
	if len(blob) == 0 {
	return types.EmptyVerkleHash, nil
	}
	n, err := verkle.ParseNode(blob, 0)
	if err != nil {
	return common.Hash{}, err
	}
	return n.Commit().Bytes(), nil
	if isVerkle { // Compute the node hash in verkle tree manner
	if len(blob) == 0 {
	return types.EmptyVerkleHash, nil
	}
	if n, err := verkle.ParseNode(blob, 0); err != nil {
	return common.Hash{}, err
	} else {
	return n.Commit().Bytes(), nil
	}
	}
	if len(blob) == 0 {
	return types.EmptyRootHash, nil
	}
	return crypto.Keccak256Hash(blob), nil

[holiman]

Another way to do this would be to define two hashers:

 func mptHash(blob []byte) (common.Hash, error) {
	if len(blob) == 0 {
			return types.EmptyRootHash, nil
		}
		return crypto.Keccak256Hash(blob), nil
}
func verkleHash(blob []byte) (common.Hash, error) {
	if len(blob) == 0 {
		return types.EmptyVerkleHash, nil
	}
	n, err := verkle.ParseNode(blob, 0)
	if err != nil {
		return common.Hash{}, err
	}
	return n.Commit().Bytes(), nil
}

And then, in e.g Enalbe, you do

stored = hasher(rawdb.ReadAccountTrieNode(db.diskdb, nil))

you'd just configure the hasher to use, to be one of either mptHash or verkleHash. So whenever you set db.isVerkle, you can also set db.hasher to use the correct one.

Just an idea...

[rjl493456442]

@holiman

Yep, I encounter another big issue, is about the EmptyRootHash.

The empty root hash is different in Merkle Tree and Verkle Tree. We use EmptyRootHash (the root of empty Merkle Tree) everywhere. We should fix it first.

[rjl493456442]

Please check #30896 instead