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# -*- coding: utf-8 -*-
#
# Utility helpers
#
# Copyright (c) 2013-2020 Michael Buesch <m@bues.ch>
#
# Licensed under the terms of the GNU General Public License version 2,
# or (at your option) any later version.
#
from __future__ import division, absolute_import, print_function, unicode_literals
from pyprofibus.compat import *
import os
import time
import errno
__all__ = [
"ProfibusError",
"bytesToHex",
"intToHex",
"boolToStr",
"fileExists",
"monotonic_time",
"TimeLimit",
"FaultDebouncer",
]
class ProfibusError(Exception):
__slots__ = (
)
def bytesToHex(b, sep=" "):
if b is None:
return "None"
assert isinstance(b, (bytes, bytearray))
if not b:
return "Empty"
return sep.join("%02X" % c for c in bytearray(b))
def intToHex(val):
if val is None:
return "None"
assert isinstance(val, int)
val &= 0xFFFFFFFF
if val <= 0xFF:
return "0x%02X" % val
elif val <= 0xFFFF:
return "0x%04X" % val
elif val <= 0xFFFFFF:
return "0x%06X" % val
else:
return "0x%08X" % val
def boolToStr(val):
return str(bool(val))
def fileExists(filename):
"""Returns True, if the file exists.
Returns False, if the file does not exist.
Returns None, if another error occurred.
"""
try:
os.stat(filename)
except OSError as e:
if e.errno == errno.ENOENT:
return False
return None
return True
# Monotonic time. Returns a float second count.
if isMicropython:
def monotonic_time():
return time.ticks_ms() / 1e3
else:
monotonic_time = getattr(time, "monotonic", time.time)
class TimeLimit(object):
"""Generic timeout helper.
"""
UNLIMITED = -1 # No limit
__slots__ = (
"__limit",
"__startTime",
"__endTime",
)
# limit => The time limit, in seconds.
# Negative value = unlimited.
def __init__(self, limit = 0):
self.__limit = limit
self.start()
# (Re-)start the time.
def start(self, limit = None):
if limit is None:
limit = self.__limit
self.__limit = limit
if limit >= 0:
self.__startTime = monotonic_time()
self.__endTime = self.__startTime + limit
else:
self.__startTime = self.__endTime = -1
# Add seconds to the limit
def add(self, seconds):
if self.__limit >= 0:
self.__limit += seconds
self.__endTime = self.__startTime + self.__limit
# Returns True, if the time limit exceed.
def exceed(self):
if self.__limit < 0:
return False # Unlimited
return monotonic_time() >= self.__endTime
class FaultDebouncer(object):
"""Fault counter/debouncer.
"""
__slots__ = (
"__countMax",
"__count",
)
def __init__(self, countMax = 0xFFFF):
self.__countMax = countMax
self.reset()
def reset(self):
self.__count = 0
def inc(self):
if self.__count < self.__countMax - 2:
self.__count += 2
return (self.__count + 1) // 2
def dec(self):
if self.__count > 0:
self.__count -= 1
return (self.__count + 1) // 2
fault = inc
ok = dec
def get(self):
return (self.__count + 1) // 2
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