fix circular import

asyncua/common/connection.py

@@ -56,7 +56,7 @@ def is_chunk_count_within_limit(self, sz: int) -> bool:
             _logger.error("Number of message chunks: %s is > configured max chunk count: %s", sz, self.max_chunk_count)
         return within_limit
 
-    def create_acknowledge_and_set_limits(self, msg: ua.Hello) -> ua.Acknowledge:
+    def create_acknowledge_and_set_limits(self, msg: "ua.Hello") -> "ua.Acknowledge":
         ack = ua.Acknowledge()
         ack.ReceiveBufferSize = min(msg.ReceiveBufferSize, self.max_send_buffer)
         ack.SendBufferSize = min(msg.SendBufferSize, self.max_recv_buffer)
@@ -69,14 +69,14 @@ def create_acknowledge_and_set_limits(self, msg: ua.Hello) -> ua.Acknowledge:
         _logger.info("updating server limits to: %s", self)
         return ack
 
-    def create_hello_limits(self, msg: ua.Hello) -> ua.Hello:
+    def create_hello_limits(self, msg: "ua.Hello") -> "ua.Hello":
         msg.ReceiveBufferSize = self.max_recv_buffer
         msg.SendBufferSize = self.max_send_buffer
         msg.MaxChunkCount = self.max_chunk_count
         msg.MaxMessageSize = self.max_chunk_count
         return msg
 
-    def update_client_limits(self, msg: ua.Acknowledge) -> None:
+    def update_client_limits(self, msg: "ua.Acknowledge") -> None:
         self.max_chunk_count = msg.MaxChunkCount
         self.max_recv_buffer = msg.ReceiveBufferSize
         self.max_send_buffer = msg.SendBufferSize
@@ -394,7 +394,7 @@ def _check_incoming_chunk(self, chunk):
                     raise ua.UaError(f"Received chunk: {chunk} with wrong sequence expecting:" f" {self._peer_sequence_number}, received: {seq_num}," f" spec says to close connection")
         self._peer_sequence_number = seq_num
 
-    def receive_from_header_and_body(self, header: ua.Header, body: "Buffer") -> Union[None,ua.Message,ua.Hello,ua.Acknowledge,ua.ErrorMessage]:
+    def receive_from_header_and_body(self, header: ua.Header, body: "Buffer") -> Union[None,ua.Message,"ua.Hello",ua.Acknowledge,ua.ErrorMessage]:
         """
         Convert MessageHeader and binary body to OPC UA TCP message (see OPC UA
         specs Part 6, 7.1: Hello, Acknowledge or ErrorMessage), or a Message

asyncua/ua/ua_binary.py

@@ -6,7 +6,7 @@
 import struct
 import logging
 from io import BytesIO
-from typing import IO, Any, Callable, Optional, Sequence, Type, TypeVar, Union, TYPE_CHECKING
+from typing import IO, Any, Callable, Optional, Sequence, Type, TypeVar, Union
 import typing
 import uuid
 from enum import Enum, IntFlag
@@ -16,9 +16,6 @@
 from ..common.utils import Buffer
 from .uatypes import type_from_optional, type_is_list, type_is_union, type_from_list, types_or_list_from_union, type_allow_subclass
 
-if TYPE_CHECKING:
-    from asyncua.common.utils import Buffer
-
 _logger = logging.getLogger(__name__)
 
 T = TypeVar('T')
@@ -711,7 +708,7 @@ def header_to_binary(hdr) -> bytes:
     return b"".join(b)
 
 
-def header_from_binary(data) -> ua.Header:
+def header_from_binary(data) -> "ua.Header":
     hdr = ua.Header()
     hdr.MessageType, hdr.ChunkType, hdr.packet_size = struct.unpack("<3scI", data.read(8))
     hdr.body_size = hdr.packet_size - 8

asyncua/ua/uaprotocol_hand.py

@@ -2,7 +2,6 @@
 from dataclasses import dataclass, field
 from typing import List, TYPE_CHECKING, Optional, Union
 
-from asyncua.common.connection import MessageChunk
 from asyncua.ua import uaprotocol_auto as auto
 from asyncua.ua import uatypes
 from asyncua.common import utils