def read(
self,
logger: AirbyteLogger,
config: Mapping[str, Any],
catalog: ConfiguredAirbyteCatalog,
state: MutableMapping[str,
Any] = None) -> Iterator[AirbyteMessage]:
"""Implements the Read operation from the Airbyte Specification. See https://docs.airbyte.io/architecture/airbyte-specification."""
connector_state = copy.deepcopy(state or {})
logger.info(f"Starting syncing {self.name}")
# TODO assert all streams exist in the connector
# get the streams once in case the connector needs to make any queries to generate them
stream_instances = {s.name: s for s in self.streams(config)}
for configured_stream in catalog.streams:
try:
stream_instance = stream_instances[
configured_stream.stream.name]
yield from self._read_stream(
logger=logger,
stream_instance=stream_instance,
configured_stream=configured_stream,
connector_state=connector_state)
except Exception as e:
logger.exception(
f"Encountered an exception while reading stream {self.name}"
)
raise e
logger.info(f"Finished syncing {self.name}")
def _read_incremental(
self,
logger: AirbyteLogger,
stream_instance: Stream,
configured_stream: ConfiguredAirbyteStream,
connector_state: MutableMapping[str, Any],
) -> Iterator[AirbyteMessage]:
stream_name = configured_stream.stream.name
stream_state = connector_state.get(stream_name, {})
if stream_state:
logger.info(f"Setting state of {stream_name} stream to {stream_state.get(stream_name)}")
checkpoint_interval = stream_instance.state_checkpoint_interval
slices = stream_instance.stream_slices(
cursor_field=configured_stream.cursor_field, sync_mode=SyncMode.incremental, stream_state=stream_state
)
for slice in slices:
record_counter = 0
records = stream_instance.read_records(
sync_mode=SyncMode.incremental,
stream_slice=slice,
stream_state=stream_state,
cursor_field=configured_stream.cursor_field or None,
)
for record_data in records:
record_counter += 1
yield self._as_airbyte_record(stream_name, record_data)
stream_state = stream_instance.get_updated_state(stream_state, record_data)
if checkpoint_interval and record_counter % checkpoint_interval == 0:
yield self._checkpoint_state(stream_name, stream_state, connector_state, logger)
yield self._checkpoint_state(stream_name, stream_state, connector_state, logger)
def _read_stream(
self,
logger: AirbyteLogger,
stream_instance: Stream,
configured_stream: ConfiguredAirbyteStream,
connector_state: MutableMapping[str, Any],
) -> Iterator[AirbyteMessage]:
use_incremental = configured_stream.sync_mode == SyncMode.incremental and stream_instance.supports_incremental
if use_incremental:
record_iterator = self._read_incremental(logger, stream_instance,
configured_stream,
connector_state)
else:
record_iterator = self._read_full_refresh(stream_instance,
configured_stream)
record_counter = 0
stream_name = configured_stream.stream.name
logger.info(f"Syncing stream: {stream_name} ")
for record in record_iterator:
if record.type == MessageType.RECORD:
record_counter += 1
yield record
logger.info(f"Read {record_counter} records from {stream_name} stream")