class DBCParser(object):
"""Parses a DBC-file.
Follows docs/DBC_Specification.md"""
def __init__(self):
"""Initializes the object"""
self._mode = ('NORMAL', None)
self._can_network = CANNetwork()
self._keywords = {
'VERSION': self._parse_version,
'BU_': self._parse_nodes,
'BO_ ': self._parse_message,
'SG_ ': self._parse_signal,
'CM_ ': self._parse_description,
'BS_': self._parse_bus_configuration,
'BA_DEF_ ': self._parse_attribute_definition,
'BA_DEF_DEF_': self._parse_attribute_default_value,
'BA_ ': self._parse_attribute,
'VAL_TABLE_': self._parse_val_table,
'VAL_ ': self._parse_signal_value_dict
}
self._force_parser = None
# Method definitions
def parse_file(self, file_name):
"""Parses a dbc file
Args:
file_name: Name of the file to parse.
Returns:
CANBus object
"""
self._can_network = CANNetwork()
with open(file_name, 'r') as dbc_fh:
for line in dbc_fh:
self._parse_line(line.strip())
return self._can_network
def _parse_line(self, line):
"""Parses one line of a dbc file
Args:
line: One line of a dbc file as string
"""
if self._force_parser:
self._force_parser(line)
else:
for key, parse_function in self._keywords.items():
if line.startswith(key):
parse_function(line)
def _parse_version(self, version_str):
"""Parses a version string and updates the CANBus
Args:
version_str: String containing version informations
"""
reg = re.search('VERSION\s+"(?P<version>\S+)"', version_str)
self._can_network.version = reg.group('version')
def _parse_nodes(self, nodes_str):
"""Parses a nodes string and updates the CANBus
Args:
nodes_str: String containing nodes informations
"""
reg = re.search('BU_\s*:\s*(?P<nodes>.+)\s*', nodes_str)
node_names_str = re.sub('\s+', ' ', reg.group('nodes')).strip()
for node_name in node_names_str.split(' '):
self._can_network.add_node(CANNode(node_name))
def _parse_message(self, message_str):
"""Parses a message string and updates the CANBus
Args:
message_str: String with message informations
"""
reg = re.search(
'BO_\s+(?P<can_id>\d+)\s+(?P<name>\S+)\s*:\s*(?P<length>\d+)\s+(?P<sender>\S+)',
message_str)
message = CANMessage(int(reg.group('can_id')),
reg.group('name').strip(),
int(reg.group('length')))
self._can_network.nodes[reg.group('sender').strip()].add_message(
message)
self._mode = ('MESSAGE', message)
def _parse_signal(self, signal_str):
"""Parses a signal string and updates the CANBus
Args:
signal_str: String with signal informations
Raises:
RuntimeError: If signal definition is not in a message block
"""
if self._mode[0] != 'MESSAGE':
raise RuntimeError('Signal description not in message block')
pattern = 'SG_\s+(?P<name>\S+)\s*(?P<is_multipexer>M)?(?P<multiplexer_id>m\d+)?\s*:\s*'
pattern += '(?P<start_bit>\d+)\|(?P<length>\d+)\@(?P<endianness>[0|1])(?P<sign>[\+|\-])\s*'
pattern += '\(\s*(?P<factor>\S+)\s*,\s*(?P<offset>\S+)\s*\)\s*'
pattern += '\[\s*(?P<min_value>\S+)\s*\|\s*(?P<max_value>\S+)\s*\]\s*"(?P<unit>\S*)"\s+(?P<receivers>.+)'
reg = re.search(pattern, signal_str)
little_endian = True if reg.group(
'endianness').strip() == '1' else False
signed = True if reg.group('sign').strip() == '-' else False
receivers = [
receiver.strip() for receiver in re.sub(
'\s+', ' ', reg.group('receivers')).strip().split(' ')
]
is_multiplexer = True if reg.group('is_multipexer') else False
multiplexer_id = int(reg.group('multiplexer_id').strip()
[1:]) if reg.group('multiplexer_id') else None
signal = CANSignal(name=reg.group('name').strip(),
start_bit=int(reg.group('start_bit')),
length=int(reg.group('length')),
little_endian=little_endian,
signed=signed,
factor=float(reg.group('factor')),
offset=float(reg.group('offset')),
value_min=float(reg.group('min_value')),
value_max=float(reg.group('max_value')),
unit=reg.group('unit').strip(),
is_multiplexer=is_multiplexer,
multiplexer_id=multiplexer_id)
for node_name in receivers:
node = self._can_network.nodes[node_name]
signal.add_receiver(node)
self._mode[1].add_signal(signal)
def _parse_description(self, desc_str):
"""Parses a description string and updates the CANBus
Args:
desc_str: String with description informations
"""
pattern = 'CM_\s+(?P<node>BU_)?(?P<msg>BO_)?(?P<sig>SG_)?\s*'
pattern += '(?P<can_id>\d*)?\s*(?P<name>\S*)?\s*"(?P<value>.+)'
reg = re.search(pattern, desc_str)
desc_item = None
if reg.group('node'):
desc_item = self._can_network.nodes[reg.group('name').strip()]
elif reg.group('msg'):
desc_item = self._can_network.get_message(int(reg.group('can_id')))
elif reg.group('sig'):
desc_item = self._can_network.get_signal(
can_id=int(reg.group('can_id')),
name=reg.group('name').strip())
else:
desc_item = self._can_network
value = reg.group('value')
if value.strip()[-2:] == '";':
desc_item.description = value.replace('";', '')
self._mode = ('NORMAL', None)
else:
self._force_parser = self._parse_multiline_description
self._mode = ('MULTILINE_DESCRIPTION', (desc_item, value + '\n'))
def _parse_multiline_description(self, line):
"""Parses the following lines of a multiline description and updates the CANBus
Args:
line: following lines of a multiline description
"""
if line.strip()[-2:] == '";':
self._mode[1][0].description = self._mode[1][1] + line.replace(
'";', '')
self._force_parser = False
self._mode = ('NORMAL', None)
else:
self._mode = (self._mode[0], (self._mode[1][0],
self._mode[1][1] + line))
def _parse_bus_configuration(self, bus_config_str):
"""Parses a bus configuration string and updates the CANBus
Args:
bus_config_str: String with bus configuration definition
"""
pattern = 'BS_\s*:\s*(?P<speed>\d+)?\s*'
reg = re.search(pattern, bus_config_str)
if reg.group('speed'):
self._can_network.speed = int(reg.group('speed'))
def _parse_attribute_definition(self, attribute_definition_str):
"""Parses a attribute definition string and updates the CANBus
Args:
attribute_definition_str: String with attribute definition definition
"""
pattern = 'BA_DEF_\s+(?P<obj_type>\S+)?\s*"(?P<attr_name>\S+)"\s+'
pattern += '(?P<attr_type>\S+)\s*(?P<attr_config>.+)?\s*;'
reg = re.search(pattern, attribute_definition_str)
obj_type = CANNetwork
if 'BU_' in reg.groups():
obj_type = CANNode
elif 'BO_' in reg.groups():
obj_type = CANMessage
elif 'SG_' in reg.groups():
obj_type = CANSignal
ad = None
if reg.group('attr_type') == 'FLOAT':
reg_cfg = re.search('\s*(?P<min>\S+)\s*(?P<max>\S+)',
reg.group('attr_config'))
ad = CANFloatAttributeDefinition(reg.group('attr_name'), obj_type,
float(reg_cfg.group('min')),
float(reg_cfg.group('max')))
elif reg.group('attr_type') == 'INT':
reg_cfg = re.search('\s*(?P<min>\S+)\s*(?P<max>\S+)',
reg.group('attr_config'))
ad = CANIntAttributeDefinition(reg.group('attr_name'), obj_type,
float(reg_cfg.group('min')),
float(reg_cfg.group('max')))
elif reg.group('attr_type') == 'STRING':
ad = CANStringAttributeDefinition(reg.group('attr_name'), obj_type)
elif reg.group('attr_type') == 'ENUM':
values = reg.group('attr_config').split(',')
values = list(map(lambda val: val.replace('"', '').strip(),
values))
ad = CANEnumAttributeDefinition(reg.group('attr_name'), obj_type,
values)
else:
raise AttributeError('Attribute definition type unkown')
self._can_network.attributes.add_definition(ad)
def _parse_attribute_value(self, cad, attr_value_str):
"""Parses a attribute value string
Args:
attr_value_str: String with attribute value
Returns:
Parse attribute value
"""
if type(cad) == CANStringAttributeDefinition:
reg_str = re.search('\s*"(?P<value>\S+)"\s*', attr_value_str)
attr_value_str = reg_str.group('value')
return attr_value_str
def _parse_attribute_default_value(self, attr_default_str):
"""Parses a attribute default value string and updates the CANBus
Args:
attr_default_str: String with attribute default value
"""
pattern = 'BA_DEF_DEF_\s+"(?P<attr_name>\S+)"\s+(?P<default>\S+)\s*;'
reg = re.search(pattern, attr_default_str)
cad = self._can_network.attributes.definitions[reg.group('attr_name')]
default_value = self._parse_attribute_value(cad, reg.group('default'))
cad.default = default_value
def _parse_attribute(self, attribute_str):
"""Parses a attribute string and updates the CANBus
Args:
attribute_str: String with attribute
"""
pattern = 'BA_\s+"(?P<attr_name>\S+)"\s*(?P<node>BU_)?(?P<msg>BO_)?(?P<sig>SG_)?\s*'
pattern += '(?P<can_id>\d*)?\s*(?P<name>\S*)?\s+(?P<value>\S+)\s*;'
reg = re.search(pattern, attribute_str)
can_object = self._can_network
if reg.group('node'):
can_object = self._can_network.nodes[reg.group('name')]
elif reg.group('msg'):
can_object = self._can_network.get_message(int(
reg.group('can_id')))
elif reg.group('sig'):
can_object = self._can_network.get_signal(int(reg.group('can_id')),
reg.group('name'))
cad = self._can_network.attributes.definitions[reg.group('attr_name')]
can_object.attributes.add(
CANAttribute(cad,
value=self._parse_attribute_value(
cad, reg.group('value'))))
def _parse_val_table_def(self, val_table_def_str):
"""Parses a val table definition string and updates the CANBus
Args:
val_table_def_str: String with val table value definition
Returns:
Dict representing the val table
"""
value_dict = {}
parts = re.split('\s+', val_table_def_str)
for i in range(0, len(parts), 2):
value_dict[int(parts[i])] = parts[i + 1].replace('"', '')
return value_dict
def _parse_val_table(self, val_table_str):
"""Parses a val table string and updates the CANBus
Args:
val_table_str: String with val table definition
"""
pattern = 'VAL_TABLE_\s+(?P<name>\S+)\s+(?P<val_table_def>.+)\s*;'
reg = re.search(pattern, val_table_str)
value_dict = self._parse_val_table_def(reg.group('val_table_def'))
self._can_network.add_value_dict(reg.group('name'), value_dict)
def _parse_signal_value_dict(self, sig_val_dict_str):
"""Parses a val string and updates the CANBus
Args:
sig_val_dict_str: String with val definition
"""
pattern = 'VAL_\s+(?P<can_id>\d+)\s+(?P<signal_name>\S+)\s+(?P<val_table_def>.+)\s*;'
reg = re.search(pattern, sig_val_dict_str)
if re.search('\s+', reg.group('val_table_def')):
value_dict = self._parse_val_table_def(reg.group('val_table_def'))
else:
value_dict = self._can_network.value_dicts[reg.group(
'val_table_def')]
self._can_network.get_signal(
int(reg.group('can_id')),
reg.group('signal_name')).value_dict = value_dict
def test_add_value_dict(self):
cn = CANNetwork()
value_dict = {0: 'Val0'}
cn.add_value_dict('ValueDict', value_dict)
assert len(cn.value_dicts) == 1
assert 'ValueDict' in cn.value_dicts