class StructTemplate(_Template):
has_length = False
def __init__(self, type, name, parent, parameters=None, length=None, align=None):
self._parameters = parameters or {}
self.type = type
if length:
self._set_length(length)
self._align = int(align or 1)
_Template.__init__(self, name, parent)
def _set_length(self, length):
self.has_length = True
self.length = Length(length)
def get_static_length(self):
return sum(field.get_static_length() for field in self._fields.values())
def decode(self, data, parent=None, name=None, little_endian=False):
if self.has_length:
length = self.length.decode(parent)
data = data[:length]
return _Template.decode(self, data, parent, name, little_endian)
def encode(self, message_params, parent=None, name=None, little_endian=False):
struct = self._get_struct(name, parent)
self._add_struct_params(message_params)
self._encode_fields(struct,
self._get_params_sub_tree(message_params, name),
little_endian=little_endian)
if self.has_length:
length, aligned_length = self.length.find_length_and_set_if_necessary(parent, len(struct))
if len(struct) != length:
raise AssertionError('Length of struct %s does not match defined length. defined length:%s Struct:\n%s' % (self.name, length, repr(struct)))
return struct
# TODO: Cleanup setting the parent to constructor of message -elements
def _get_struct(self, name, parent):
struct = Struct(name or self.name, self.type, align=self._align)
struct._parent = parent
return struct
def validate(self, parent, message_fields, name=None):
self._add_struct_params(message_fields)
errors = []
name = name or self.name
message = parent[name]
if self.has_length:
length = self.length.decode(message)
if len(message) != length:
errors.append('Length of struct %s does not match defined length. defined length:%s struct length:%s' % (message._name, length, len(message)))
return errors + _Template.validate(self, message, self._get_params_sub_tree(message_fields, name))
def _add_struct_params(self, params):
for key in self._parameters.keys():
params[key] = self._parameters.pop(key) if key not in params else params[key]
def __init__(self, length, name, parent):
self.length = Length(length)
_Template.__init__(self, name, parent)
class ListTemplate(_Template):
param_pattern = re.compile(r'([^.]*?)\[(.*?)\](.*)')
has_length = True
type = 'List'
def __init__(self, length, name, parent):
self.length = Length(length)
_Template.__init__(self, name, parent)
def get_static_length(self):
return self.length.value * self.field.get_static_length()
def encode(self, message_params, parent, name=None, little_endian=False):
name = name or self.name
params_subtree = self._get_params_sub_tree(message_params, name)
list = self._get_struct(name, parent)
for index in range(self.length.decode(parent)):
list[str(index)] = self.field.encode(params_subtree,
parent,
name=str(index),
little_endian=little_endian)
self._check_params_empty(params_subtree, name)
return list
@property
def field(self):
return self._fields.values()[0]
def _get_struct(self, name=None, parent=None):
ls = List(name or self.name, self.field.type)
ls._parent = parent
return ls
def decode(self, data, parent, name=None, little_endian=False):
name = name or self.name
message = self._get_struct(name, parent)
data_index = 0
# maximum_length is given for free length (*) to limit the absolute maximum number of entries
for index in range(0, self.length.decode(parent, maximum_length=len(data))):
message[str(index)] = self.field.decode(data[data_index:], message, name=str(index), little_endian=little_endian)
data_index += len(message[index])
if self.length.free and data_index == len(data):
break
return message
def validate(self, parent, message_fields, name=None):
name = name or self.name
params_subtree = self._get_params_sub_tree(message_fields, name)
list = parent[name]
errors = []
for index in range(list.len):
errors += self.field.validate(list, params_subtree, name=str(index))
self._check_params_empty(params_subtree, name)
return errors
def _get_params_sub_tree(self, params, name=None):
result = OrderedDict({'*': params['*']} if '*' in params else {})
name = name or self.name
for key in params.keys():
self._consume_params_with_brackets(name, params, result, key)
self._consume_dot_syntax(name, params, result, key)
return result
def _consume_params_with_brackets(self, name, params, result, key):
match = self.param_pattern.match(key)
if match:
prefix, child_name, ending = match.groups()
if prefix == name:
result[child_name + ending] = params.pop(key)
elif prefix == '*':
result[child_name + ending] = params[key]
def _consume_dot_syntax(self, name, params, result, key):
prefix, _, ending = key.partition('.')
if prefix == name:
result[ending] = params.pop(key)
elif prefix == '*' and ending:
result[ending] = params[key]
def _set_length(self, length):
self.has_length = True
self.length = Length(length)
