Skip to content
Navigation Menu
{{ message }}
forked from hardbyte/python-can
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathutil.py
More file actions
287 lines (221 loc) · 7.95 KB
/
Copy pathutil.py
File metadata and controls
287 lines (221 loc) · 7.95 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
"""
Utilities and configuration file parsing.
"""
from typing import Dict, Optional, Union
from can import typechecking
import json
import os
import os.path
import platform
import re
import logging
from configparser import ConfigParser
import can
from can.interfaces import VALID_INTERFACES
log = logging.getLogger("can.util")
# List of valid data lengths for a CAN FD message
CAN_FD_DLC = [0, 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, 32, 48, 64]
REQUIRED_KEYS = ["interface", "channel"]
CONFIG_FILES = ["~/can.conf"]
if platform.system() == "Linux":
CONFIG_FILES.extend(["/etc/can.conf", "~/.can", "~/.canrc"])
elif platform.system() == "Windows" or platform.python_implementation() == "IronPython":
CONFIG_FILES.extend(["can.ini", os.path.join(os.getenv("APPDATA", ""), "can.ini")])
def load_file_config(
path: Optional[typechecking.AcceptedIOType] = None, section: str = "default"
) -> Dict[str, str]:
"""
Loads configuration from file with following content::
[default]
interface = socketcan
channel = can0
:param path:
path to config file. If not specified, several sensible
default locations are tried depending on platform.
:param section:
name of the section to read configuration from.
"""
config = ConfigParser()
if path is None:
config.read([os.path.expanduser(path) for path in CONFIG_FILES])
else:
config.read(path)
_config = {}
if config.has_section(section):
_config.update(dict((key, val) for key, val in config.items(section)))
return _config
def load_environment_config(context: Optional[str] = None) -> Dict[str, str]:
"""
Loads config dict from environmental variables (if set):
* CAN_INTERFACE
* CAN_CHANNEL
* CAN_BITRATE
* CAN_CONFIG
if context is supplied, "_{context}" is appended to the environment
variable name we will look at. For example if context="ABC":
* CAN_INTERFACE_ABC
* CAN_CHANNEL_ABC
* CAN_BITRATE_ABC
* CAN_CONFIG_ABC
"""
mapper = {
"interface": "CAN_INTERFACE",
"channel": "CAN_CHANNEL",
"bitrate": "CAN_BITRATE",
}
context_suffix = "_{}".format(context) if context else ""
can_config_key = "CAN_CONFIG" + context_suffix
config: Dict[str, str] = json.loads(os.environ.get(can_config_key, "{}"))
for key, val in mapper.items():
config_option = os.environ.get(val + context_suffix, None)
if config_option:
config[key] = config_option
return config
def load_config(
path: Optional[typechecking.AcceptedIOType] = None,
config=None,
context: Optional[str] = None,
) -> typechecking.BusConfig:
"""
Returns a dict with configuration details which is loaded from (in this order):
- config
- can.rc
- Environment variables CAN_INTERFACE, CAN_CHANNEL, CAN_BITRATE
- Config files ``/etc/can.conf`` or ``~/.can`` or ``~/.canrc``
where the latter may add or replace values of the former.
Interface can be any of the strings from ``can.VALID_INTERFACES`` for example:
kvaser, socketcan, pcan, usb2can, ixxat, nican, virtual.
.. note::
The key ``bustype`` is copied to ``interface`` if that one is missing
and does never appear in the result.
:param path:
Optional path to config file.
:param config:
A dict which may set the 'interface', and/or the 'channel', or neither.
It may set other values that are passed through.
:param context:
Extra 'context' pass to config sources. This can be use to section
other than 'default' in the configuration file.
:return:
A config dictionary that should contain 'interface' & 'channel'::
{
'interface': 'python-can backend interface to use',
'channel': 'default channel to use',
# possibly more
}
Note ``None`` will be used if all the options are exhausted without
finding a value.
All unused values are passed from ``config`` over to this.
:raises:
NotImplementedError if the ``interface`` isn't recognized
"""
# start with an empty dict to apply filtering to all sources
given_config = config or {}
config = {}
# use the given dict for default values
config_sources = [
given_config,
can.rc,
lambda _context: load_environment_config( # pylint: disable=unnecessary-lambda
_context
),
lambda _context: load_environment_config(),
lambda _context: load_file_config(path, _context),
lambda _context: load_file_config(path),
]
# Slightly complex here to only search for the file config if required
for cfg in config_sources:
if callable(cfg):
cfg = cfg(context)
# remove legacy operator (and copy to interface if not already present)
if "bustype" in cfg:
if "interface" not in cfg or not cfg["interface"]:
cfg["interface"] = cfg["bustype"]
del cfg["bustype"]
# copy all new parameters
for key in cfg:
if key not in config:
config[key] = cfg[key]
# substitute None for all values not found
for key in REQUIRED_KEYS:
if key not in config:
config[key] = None
if config["interface"] not in VALID_INTERFACES:
raise NotImplementedError(
"Invalid CAN Bus Type - {}".format(config["interface"])
)
if "bitrate" in config:
config["bitrate"] = int(config["bitrate"])
if "fd" in config:
config["fd"] = config["fd"] not in ("0", "False", "false")
if "data_bitrate" in config:
config["data_bitrate"] = int(config["data_bitrate"])
# Create bit timing configuration if given
timing_conf = {}
for key in (
"f_clock",
"brp",
"tseg1",
"tseg2",
"sjw",
"nof_samples",
"btr0",
"btr1",
):
if key in config:
timing_conf[key] = int(config[key], base=0)
del config[key]
if timing_conf:
timing_conf["bitrate"] = config.get("bitrate")
config["timing"] = can.BitTiming(**timing_conf)
can.log.debug("can config: {}".format(config))
return config
def set_logging_level(level_name: Optional[str] = None):
"""Set the logging level for the "can" logger.
Expects one of: 'critical', 'error', 'warning', 'info', 'debug', 'subdebug'
"""
can_logger = logging.getLogger("can")
try:
can_logger.setLevel(getattr(logging, level_name.upper())) # type: ignore
except AttributeError:
can_logger.setLevel(logging.DEBUG)
log.debug("Logging set to {}".format(level_name))
def len2dlc(length: int) -> int:
"""Calculate the DLC from data length.
:param int length: Length in number of bytes (0-64)
:returns: DLC (0-15)
"""
if length <= 8:
return length
for dlc, nof_bytes in enumerate(CAN_FD_DLC):
if nof_bytes >= length:
return dlc
return 15
def dlc2len(dlc: int) -> int:
"""Calculate the data length from DLC.
:param dlc: DLC (0-15)
:returns: Data length in number of bytes (0-64)
"""
return CAN_FD_DLC[dlc] if dlc <= 15 else 64
def channel2int(channel: Optional[Union[typechecking.Channel]]) -> Optional[int]:
"""Try to convert the channel to an integer.
:param channel:
Channel string (e.g. can0, CAN1) or integer
:returns: Channel integer or `None` if unsuccessful
"""
if channel is None:
return None
if isinstance(channel, int):
return channel
# String and byte objects have a lower() method
if hasattr(channel, "lower"):
match = re.match(r".*(\d+)$", channel)
if match:
return int(match.group(1))
return None
if __name__ == "__main__":
print("Searching for configuration named:")
print("\n".join(CONFIG_FILES))
print()
print("Settings:")
print(load_config())
You can’t perform that action at this time.