#NEWLINE# def initialize( self ) : #NEWLINE# #INDENT# super ( FileBTreeDB4 , self ) . initialize ( ) #NEWLINE# stream = self . get_user_header ( ) #NEWLINE# db_format = sbon . read_fixlen_string ( stream , 12 ) #NEWLINE# assert ( db_format == 'BTreeDB4' ) , 'Expected binary tree database' #NEWLINE# self . identifier = sbon . read_fixlen_string ( stream , 12 ) #NEWLINE# fields = struct . unpack ( '>i?xi?xxxi?' , stream . read ( 19 ) ) #NEWLINE# self . key_size = fields [ 0 ] #NEWLINE# self . alternate_root_node = fields [ 1 ] #NEWLINE# if self . alternate_root_node : #NEWLINE# #INDENT# ( self . root_node , self . root_node_is_leaf ) = fields [ 4 : 6 ] #NEWLINE# ( self . other_root_node , self . other_root_node_is_leaf ) = fields [ 2 : 4 ] #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# ( self . root_node , self . root_node_is_leaf ) = fields [ 2 : 4 ] #NEWLINE# ( self . other_root_node , self . other_root_node_is_leaf ) = fields [ 4 : 6 ]