// GetState returns a value in account storage.
func (self *StateObject) GetState(db trie.Database, key common.Hash) common.Hash {
value, exists := self.cachedStorage[key]
if exists {
return value
}
// Load from DB in case it is missing.
if enc := self.getTrie(db).Get(key[:]); len(enc) > 0 {
_, content, _, err := rlp.Split(enc)
if err != nil {
self.setError(err)
}
value.SetBytes(content)
}
if (value != common.Hash{}) {
self.cachedStorage[key] = value
}
return value
}
func decodeRef(buf []byte) (node, []byte, error) {
kind, val, rest, err := rlp.Split(buf)
if err != nil {
return nil, buf, err
}
switch {
case kind == rlp.List:
// 'embedded' node reference. The encoding must be smaller
// than a hash in order to be valid.
if size := len(buf) - len(rest); size > hashLen {
err := fmt.Errorf("oversized embedded node (size is %d bytes, want size < %d)", size, hashLen)
return nil, buf, err
}
n, err := decodeNode(buf)
return n, rest, err
case kind == rlp.String && len(val) == 0:
// empty node
return nil, rest, nil
case kind == rlp.String && len(val) == 32:
return hashNode(val), rest, nil
default:
return nil, nil, fmt.Errorf("invalid RLP string size %d (want 0 or 32)", len(val))
}
}