#
# Copyright (C) 2014-2015 UAVCAN Development Team <uavcan.org>
#
# This software is distributed under the terms of the MIT License.
#
# Author: Ben Dyer <ben_dyer@mac.com>
# Pavel Kirienko <pavel.kirienko@zubax.com>
#
"""
Python UAVCAN package.
Supported Python versions: 3.2+, 2.7.
"""
from __future__ import division, absolute_import, print_function, unicode_literals
import os
import sys
import struct
import pkg_resources
import time
from logging import getLogger
try:
# noinspection PyStatementEffect
time.monotonic # Works natively in Python 3.3+
except AttributeError:
try:
# noinspection PyPackageRequirements,PyUnresolvedReferences
import monotonic # 3rd party dependency for old versions @UnresolvedImport
# monotonic_wrapper is a temporary work around for https://github.com/UAVCAN/pyuavcan/issues/22
# monotonic_wrapper stops arguments being passed to monotonic.monotonic
def monotonic_wrapper(*args, **kwargs):
return monotonic.monotonic()
time.monotonic = monotonic_wrapper
except ImportError:
time.monotonic = time.time # Last resort - using non-monotonic time; this is no good but oh well
print('''The package 'monotonic' is not available, the library will use real time instead of monotonic time.
This implies that the library may misbehave if system clock is adjusted while the library is running.
In order to fix this problem, consider either option:
1. Switch to Python 3.
2. Install the missing package, e.g. using pip:
pip install monotonic''', file=sys.stderr)
class UAVCANException(Exception):
pass
from .version import __version__
import uavcan.node as node
from uavcan.node import make_node
from uavcan.driver import make_driver
import uavcan.dsdl as dsdl
import uavcan.transport as transport
from uavcan.transport import get_uavcan_data_type, \
get_active_union_field, switch_union_field, is_union, \
get_constants, get_fields, \
is_request, is_response
from uavcan.introspect import value_to_constant_name, to_yaml
TRANSFER_PRIORITY_LOWEST = 31
TRANSFER_PRIORITY_HIGHEST = 0
logger = getLogger(__name__)
class Module(object):
pass
class Namespace(object):
"""Provides a nice object-based way to look up UAVCAN data types."""
def __init__(self):
self.__namespaces = set()
# noinspection PyProtectedMember
def _path(self, attrpath):
"""Returns the namespace object at the given .-separated path,
creating any namespaces in the path that don't already exist."""
attr, _, subpath = attrpath.partition(".")
if attr not in self.__dict__:
self.__dict__[attr] = Namespace()
self.__namespaces.add(attr)
if subpath:
return self.__dict__[attr]._path(subpath)
else:
return self.__dict__[attr]
def _namespaces(self):
"""Returns the top-level namespaces in this object"""
return set(self.__namespaces)
MODULE = Module()
DATATYPES = {}
TYPENAMES = {}
# noinspection PyProtectedMember
def load_dsdl(*paths, **args):
"""
Loads the DSDL files under the given directory/directories, and creates
types for each of them in the current module's namespace.
If the exclude_dist argument is not present, or False, the DSDL
definitions installed with this package will be loaded first.
Also adds entries for all datatype (ID, kind)s to the DATATYPES
dictionary, which maps datatype (ID, kind)s to their respective type
classes.
"""
global DATATYPES, TYPENAMES
paths = list(paths)
# Try to prepend the built-in DSDL files
# TODO: why do we need try/except here?
# noinspection PyBroadException
try:
if not args.get("exclude_dist", None):
dsdl_path = pkg_resources.resource_filename(__name__, "dsdl_files") # @UndefinedVariable
paths = [os.path.join(dsdl_path, "uavcan")] + paths
custom_path = os.path.join(os.path.expanduser("~"), "uavcan_vendor_specific_types")
if os.path.isdir(custom_path):
paths += [f for f in [os.path.join(custom_path, f) for f in os.listdir(custom_path)]
if os.path.isdir(f)]
except Exception:
pass
root_namespace = Namespace()
dtypes = dsdl.parse_namespaces(paths)
for dtype in dtypes:
namespace, _, typename = dtype.full_name.rpartition(".")
root_namespace._path(namespace).__dict__[typename] = dtype
TYPENAMES[dtype.full_name] = dtype
if dtype.default_dtid:
DATATYPES[(dtype.default_dtid, dtype.kind)] = dtype
# Add the base CRC to each data type capable of being transmitted
dtype.base_crc = dsdl.crc16_from_bytes(struct.pack("<Q", dtype.get_data_type_signature()))
logger.debug("DSDL Load {: >30} DTID: {: >4} base_crc:{: >8}"
.format(typename, dtype.default_dtid, hex(dtype.base_crc)))
def create_instance_closure(closure_type, _mode=None):
# noinspection PyShadowingNames
def create_instance(*args, **kwargs):
if _mode:
assert '_mode' not in kwargs, 'Mode cannot be supplied to service type instantiation helper'
kwargs['_mode'] = _mode
return transport.CompoundValue(closure_type, *args, **kwargs)
return create_instance
dtype._instantiate = create_instance_closure(dtype)
if dtype.kind == dtype.KIND_SERVICE:
dtype.Request = create_instance_closure(dtype, _mode='request')
dtype.Response = create_instance_closure(dtype, _mode='response')
namespace = root_namespace._path("uavcan")
for top_namespace in namespace._namespaces():
MODULE.__dict__[str(top_namespace)] = namespace.__dict__[top_namespace]
MODULE.__dict__["thirdparty"] = Namespace()
for ext_namespace in root_namespace._namespaces():
if str(ext_namespace) != "uavcan":
# noinspection PyUnresolvedReferences
MODULE.thirdparty.__dict__[str(ext_namespace)] = root_namespace.__dict__[ext_namespace]
__all__ = ["dsdl", "transport", "load_dsdl", "DATATYPES", "TYPENAMES"]
# Hack to support dynamically-generated attributes at the top level of the
# module. It doesn't feel right but it's recommended by Guido:
# https://mail.python.org/pipermail/python-ideas/2012-May/014969.html
MODULE.__dict__ = globals()
MODULE._module = sys.modules[MODULE.__name__]
MODULE._pmodule = MODULE
sys.modules[MODULE.__name__] = MODULE
# Completing package initialization with loading default DSDL definitions
load_dsdl()
# Importing modules that may be dependent on the standard DSDL types
import uavcan.app as app