bugfix in fields (added length property and revised __call__)

Author: JarryShaw

pcapkit/corekit/fields/collections.py

@@ -42,6 +42,11 @@ class ListField(_Field[List[_TL]]):
 
     """
 
+    @property
+    def length(self) -> 'int':
+        """Field size."""
+        return self._length
+
     @property
     def optional(self) -> 'bool':
         """Field is optional."""
@@ -121,7 +126,7 @@ def unpack(self, buffer: 'bytes | IO[bytes]', packet: 'dict[str, Any]') -> 'byte
             Unpacked field value.
 
         """
-        length = self.length
+        length = self._length
         if isinstance(buffer, bytes):
             file = io.BytesIO(buffer)  # type: IO[bytes]
         else:
@@ -134,7 +139,7 @@ def unpack(self, buffer: 'bytes | IO[bytes]', packet: 'dict[str, Any]') -> 'byte
         is_schema = isinstance(self._item_type, SchemaField)
 
         temp = []  # type: list[_TL]
-        while length:
+        while length > 0:
             field = self._item_type(packet)
 
             if is_schema:
@@ -195,6 +200,11 @@ def eool(self) -> 'int | StdlibEnum | AenumEnum':
         """EOOL option."""
         return self._eool
 
+    @property
+    def option_padding(self) -> 'int':
+        """Length option padding data."""
+        return self._option_padding
+
     def __init__(self, length: 'int | Callable[[dict[str, Any]], int]' = lambda _: -1,
                  base_schema: 'Optional[Type[Schema]]' = None,
                  type_name: 'str' = 'type',
@@ -204,6 +214,7 @@ def __init__(self, length: 'int | Callable[[dict[str, Any]], int]' = lambda _: -
         super().__init__(length, None, callback)
         self._name = '<option>'
         self._eool = eool
+        self._option_padding = 0
 
         if base_schema is None:
             raise FieldValueError('Field <option> has no base schema.')
@@ -229,12 +240,12 @@ def unpack(self, buffer: 'bytes | IO[bytes]', packet: 'dict[str, Any]') -> 'list
 
         Important:
             If the option list ended before the specified size limit,
-            inject ``__option_padding__`` as the remaining length to
+            set :attr:`self.option_padding <OptionField.option_padding>` as the remaining length to
             the ``packet`` argument such that the next fields can be
             aware of such informations.
 
         """
-        length = self.length
+        length = self._length
         if isinstance(buffer, bytes):
             file = io.BytesIO(buffer)  # type: IO[bytes]
         else:
@@ -246,7 +257,7 @@ def unpack(self, buffer: 'bytes | IO[bytes]', packet: 'dict[str, Any]') -> 'list
         new_packet[self.name] = OrderedMultiDict()
 
         temp = []  # type: list[Schema]
-        while length:
+        while length > 0:
             # unpack option type using base schema
             meta = self._base_schema.unpack(file, length, packet)  # type: ignore[call-arg,misc,var-annotated]
             code = cast('int', meta[self._type_name])
@@ -265,6 +276,7 @@ def unpack(self, buffer: 'bytes | IO[bytes]', packet: 'dict[str, Any]') -> 'list
 
             # check for EOOL
             if code == self._eool:
-                packet['__option_padding__'] = length
                 break
+
+        self._option_padding = length
         return temp

pcapkit/corekit/fields/misc.py

@@ -32,6 +32,8 @@
 class NoValueField(_Field[_TN]):
     """Schema field for no value type (or :obj:`None`)."""
 
+    _default = NoValue
+
     @property
     def template(self) -> 'str':
         """Field template."""
@@ -426,7 +428,8 @@ def __call__(self, packet: 'dict[str, Any]') -> 'SwitchField[_TC]':
 
         """
         new_self = copy.copy(self)
-        new_self._field = self._selector(packet)(packet)
+        new_self._field = new_self._selector(packet)(packet)
+        new_self._field.name = self.name
         return new_self
 
     def pre_process(self, value: '_TC', packet: 'dict[str, Any]') -> 'Any':  # pylint: disable=unused-argument
@@ -504,6 +507,11 @@ class SchemaField(_Field[_TS]):
 
     """
 
+    @property
+    def length(self) -> 'int':
+        """Field size."""
+        return self._length  # type: ignore[has-type]
+
     @property
     def optional(self) -> 'bool':
         """Field is optional."""

pcapkit/corekit/fields/numbers.py

@@ -99,9 +99,9 @@ def __call__(self, packet: 'dict[str, Any]') -> 'Self':
         """
         new_self = super().__call__(packet)
 
-        if self._bit_length < 0:
-            self._bit_length = self._length * 8
-            self._bit_mask = (1 << self._bit_length) - 1
+        if new_self._bit_length < 0:
+            new_self._bit_length = new_self._length * 8
+            new_self._bit_mask = (1 << new_self._bit_length) - 1
 
         endian = '>' if new_self._byteorder == 'big' else '<'
         struct_fmt = new_self.build_template(new_self._length, new_self._signed)