def write(self, value: bytes, request: AmsPacket = None):
"""Update the variable value, respecting notifications"""
if self.value != value:
if self.notifications:
header = structs.SAdsNotificationHeader()
header.hNotification = 0
header.nTimeStamp = dt_to_filetime(datetime.now())
header.cbSampleSize = len(value)
# Perform byte-write into the header
dst = ctypes.addressof(
header) + structs.SAdsNotificationHeader.data.offset
ctypes.memmove(dst, value, len(value))
for notification_handle in self.notifications:
# It's hard to guess the exact AmsAddr from here, so instead
# ignore the address and search for the note_handle
for key, func in callback_store.items():
# callback_store is keyed by (AmsAddr, int)
if key[1] != notification_handle:
continue
header.hNotification = notification_handle
addr = key[0]
# Call c-wrapper for user callback
func(addr.amsAddrStruct(), header, 0)
self.value = value
def test_ads_notification_stream(self):
dt = datetime.datetime(2017, 9, 1, 10, 10, 10)
filetime = dt_to_filetime(dt)
stream = structs.AdsNotificationStream([
structs.AdsStampHeader(
timestamp=filetime,
samples=[
structs.AdsNotificationSample(
handle=1,
sample_size=ctypes.sizeof(pyads.PLCTYPE_INT),
data=struct.pack("<H", 12),
)
],
)
])
self.assertEqual(
b"\x16\x00\x00\x00" # length
b"\x01\x00\x00\x00" # stamp count
b"\x00\xadT~\n#\xd3\x01" # stamp timestamp
b"\x01\x00\x00\x00" # stamp sample count
b"\x01\x00\x00\x00" # sample handle
b"\x02\x00\x00\x00" # sample sample_size
b"\x0C\x00", # sample data
stream.to_bytes(),
)
self.assertEqual(stream.length, 30)
def test_ads_notification_stream(self):
dt = datetime.datetime(2017, 9, 1, 10, 10, 10)
filetime = dt_to_filetime(dt)
stream = structs.AdsNotificationStream([
structs.AdsStampHeader(
timestamp=filetime,
samples=[structs.AdsNotificationSample(
handle=1,
sample_size=ctypes.sizeof(pyads.PLCTYPE_INT),
data=struct.pack('<H', 12)
)]
)
])
self.assertEqual(
b'\x16\x00\x00\x00' # length
b'\x01\x00\x00\x00' # stamp count
b'\x00\xadT~\n#\xd3\x01' # stamp timestamp
b'\x01\x00\x00\x00' # stamp sample count
b'\x01\x00\x00\x00' # sample handle
b'\x02\x00\x00\x00' # sample sample_size
b'\x0C\x00', # sample data
stream.to_bytes()
)
self.assertEqual(stream.length, 30)
def test_filetime_dt_conversion(self):
dt_now = datetime(2017, 10, 13, 10, 11, 12)
ft = dt_to_filetime(dt_now)
dt = filetime_to_dt(ft)
# should be identical
self.assertEqual(dt_now, dt)
def test_filetime_dt_conversion(self):
dt_now = datetime(2017, 10, 13, 10, 11, 12)
ft = dt_to_filetime(dt_now)
dt = filetime_to_dt(ft)
# should be identical
self.assertEqual(dt_now, dt)
def test_ads_stamp_header(self):
dt = datetime.datetime(2017, 9, 1, 10, 10, 10)
filetime = dt_to_filetime(dt)
stamp_header = structs.AdsStampHeader(
timestamp=filetime,
samples=[
structs.AdsNotificationSample(handle=1,
sample_size=ctypes.sizeof(
pyads.PLCTYPE_INT),
data=struct.pack('<H', 12))
])
self.assertEqual(
b'\x00\xadT~\n#\xd3\x01' # timestamp
b'\x01\x00\x00\x00' # sample count
b'\x01\x00\x00\x00' # sample handle
b'\x02\x00\x00\x00' # sample sample_size
b'\x0C\x00', # sample data
stamp_header.to_bytes())
self.assertEqual(stamp_header.length, 22)