mpt: do not create an Extension for the last child of a Branch

Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>
This commit is contained in:
Evgeniy Stratonikov 2021-07-07 14:04:29 +03:00
parent 25428d53f1
commit a33e422b79
2 changed files with 20 additions and 1 deletions

View file

@ -192,7 +192,10 @@ func (t *Trie) stripBranch(b *BranchNode) (Node, error) {
case n == 0:
return new(HashNode), nil
case n == 1:
return t.mergeExtension([]byte{lastIndex}, b.Children[lastIndex])
if lastIndex != lastChild {
return t.mergeExtension([]byte{lastIndex}, b.Children[lastIndex])
}
return b.Children[lastIndex], nil
default:
t.addRef(b.Hash(), b.bytes)
return b, nil

View file

@ -174,6 +174,22 @@ func TestTrie_PutBatchBranch(t *testing.T) {
testPut(t, ps, tr1, tr2)
require.IsType(t, (*ExtensionNode)(nil), tr1.root)
})
t.Run("non-empty child is last node", func(t *testing.T) {
tr1 := NewTrie(new(HashNode), false, newTestStore())
tr2 := NewTrie(new(HashNode), false, newTestStore())
require.NoError(t, tr1.Put([]byte{0x00, 2}, []byte("value1")))
require.NoError(t, tr2.Put([]byte{0x00, 2}, []byte("value1")))
require.NoError(t, tr1.Put([]byte{0x00}, []byte("value2")))
require.NoError(t, tr2.Put([]byte{0x00}, []byte("value2")))
tr1.Flush()
tr1.Collapse(1)
tr2.Flush()
tr2.Collapse(1)
var ps = pairs{{[]byte{0x00, 2}, nil}}
testPut(t, ps, tr1, tr2)
})
})
t.Run("incomplete put, transform to extension", func(t *testing.T) {
tr1, tr2 := prepareBranch(t)