<s> import uuid <EOL> FRAME_ERROR_TYPE = b'<STR_LIT:error>' <EOL> FRAME_RESPONSE_TYPE = b'<STR_LIT>' <EOL> FRAME_MESSAGE_TYPE = b'<STR_LIT:message>' <EOL> MAGIC_V1 = b"<STR_LIT>" <EOL> class MessageError ( Exception ) : <EOL> """<STR_LIT>""" <EOL> class Message ( object ) : <EOL> """<STR_LIT>""" <EOL> def __init__ ( self , body = None , id = None , type = FRAME_MESSAGE_TYPE ) : <EOL> self . body = body or b"<STR_LIT>" <EOL> if not isinstance ( self . body , bytes ) : <EOL> self . body = self . body . encode ( '<STR_LIT:utf-8>' ) <EOL> self . id = id or uuid . uuid4 ( ) . hex <EOL> if not isinstance ( self . id , bytes ) : <EOL> self . id = self . id . encode ( '<STR_LIT:utf-8>' ) <EOL> self . type = type <EOL> def __str__ ( self ) : <EOL> return "<STR_LIT>" % self . id . decode ( "<STR_LIT:utf-8>" ) <EOL> @ classmethod <EOL> def decode_frame ( cls , frame ) : <EOL> if not isinstance ( frame , bytes ) : <EOL> frame = frame . encode ( '<STR_LIT:utf-8>' ) <EOL> try : <EOL> header , body = frame . split ( b"<STR_LIT>" ) <EOL> _ , type , id = header . split ( ) <EOL> return cls ( body , id = id , type = type ) <EOL> except ValueError : <EOL> raise MessageError ( "<STR_LIT>" % frame ) <EOL> def encode ( self ) : <EOL> """<STR_LIT>""" <EOL> header = b"<STR_LIT:U+0020>" . join ( [ MAGIC_V1 , self . type , self . id ] ) <EOL> return b"<STR_LIT>" . join ( [ header , b"<STR_LIT>" , self . body ] ) <EOL> def decode_frame ( frame ) : <EOL> return Message . decode_frame ( frame ) <EOL> def make_response ( body , id = None ) : <EOL> return Message ( body , id = id , type = FRAME_RESPONSE_TYPE ) </s>
