def test_update_handler_throws_if_schema_not_recognised():
producer = FakeProducer()
context = FakeContext()
non_existing_schema = "DOESNTEXIST"
with pytest.raises(ValueError):
CAUpdateHandler(producer, context, "source_name", "output_topic",
non_existing_schema) # type: ignore
def test_update_handler_publishes_enum_update():
producer = FakeProducer()
context = FakeContext()
pv_caproto_type = ChannelType.TIME_ENUM
pv_source_name = "source_name"
update_handler = CAUpdateHandler(producer, context, pv_source_name,
"output_topic", "f142") # type: ignore
# Nothing gets published when ENUM type update is received, the handler will resubscribe using STRING
# type as the string is more useful to forwarder to the filewriter than the enum int
metadata = (0, 0, TimeStamp(4, 0))
context.call_monitor_callback_with_fake_pv_update(
ReadNotifyResponse(
np.array([0]),
pv_caproto_type,
1,
1,
1,
metadata=metadata,
))
# Second update, with STRING type
enum_string_value = "ENUM_STRING"
context.call_monitor_callback_with_fake_pv_update(
ReadNotifyResponse(
[enum_string_value.encode("utf8")],
ChannelType.TIME_STRING,
1,
1,
1,
metadata=metadata,
))
assert (
producer.messages_published == 1
), "Only expected a single message with string payload, not the original enum update"
assert producer.published_payload is not None
pv_update_output = deserialise_f142(producer.published_payload)
assert pv_update_output.value == enum_string_value
assert pv_update_output.source_name == pv_source_name
update_handler.stop()
def test_update_handler_does_not_include_alarm_details_if_unchanged_in_subsequent_updates(
):
producer = FakeProducer()
context = FakeContext()
pv_value = 42
pv_caproto_type = ChannelType.TIME_INT
pv_numpy_type = np.int32
pv_source_name = "source_name"
alarm_status = 6 # AlarmStatus.LOW
alarm_severity = 1 # AlarmSeverity.MINOR
update_handler = CAUpdateHandler(producer, context, pv_source_name,
"output_topic", "f142") # type: ignore
metadata = (alarm_status, alarm_severity, TimeStamp(4, 0))
context.call_monitor_callback_with_fake_pv_update(
ReadNotifyResponse(
np.array([pv_value]).astype(pv_numpy_type),
pv_caproto_type,
1,
1,
1,
metadata=metadata,
))
# Second update, with unchanged alarm
context.call_monitor_callback_with_fake_pv_update(
ReadNotifyResponse(
np.array([pv_value]).astype(pv_numpy_type),
pv_caproto_type,
1,
1,
1,
metadata=metadata,
))
assert producer.messages_published == 2
pv_update_output = deserialise_f142(producer.published_payload)
assert pv_update_output.alarm_status == AlarmStatus.NO_CHANGE
assert pv_update_output.alarm_severity == AlarmSeverity.NO_CHANGE
update_handler.stop()
def create_update_handler(
producer: KafkaProducer,
ca_context: CAContext,
pva_context: PVAContext,
channel: ConfigChannel,
fake_pv_period_ms: int,
periodic_update_ms: Optional[int] = None,
) -> UpdateHandler:
if not channel.name:
raise RuntimeError(
"PV name not specified when adding handler for channel")
if not channel.output_topic:
raise RuntimeError(
f"Output topic not specified when adding handler for channel {channel.name}"
)
if not channel.schema:
raise RuntimeError(
f"Schema not specified when adding handler for channel {channel.name}"
)
if channel.protocol == EpicsProtocol.PVA:
return PVAUpdateHandler(
producer,
pva_context,
channel.name,
channel.output_topic,
channel.schema,
periodic_update_ms,
)
elif channel.protocol == EpicsProtocol.CA:
return CAUpdateHandler(
producer,
ca_context,
channel.name,
channel.output_topic,
channel.schema,
periodic_update_ms,
)
elif channel.protocol == EpicsProtocol.FAKE:
return FakeUpdateHandler(
producer,
channel.name,
channel.output_topic,
channel.schema,
fake_pv_period_ms,
)
raise RuntimeError("Unexpected EpicsProtocol in create_update_handler")