flink-python/pyflink/fn_execution/__init__.py

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import logging
import os

_LOG = logging.getLogger(__name__)

if 'PYFLINK_CYTHON_ENABLED' in os.environ:
    PYFLINK_CYTHON_ENABLED = bool(os.environ['PYFLINK_CYTHON_ENABLED'])
    if not PYFLINK_CYTHON_ENABLED:
        _LOG.info("PYFLINK_CYTHON_ENABLED is set to False via environment variable.")
else:
    PYFLINK_CYTHON_ENABLED = True

# Supported combinations：
# 1) PyFlink Fast + Beam Fast
# 2) PyFlink Slow + Beam Slow
# 3) PyFlink Slow + Beam Fast

# Check whether beam could be fast and force PyFlink to be slow if beam is slow
try:
    from apache_beam.coders import stream # noqa # pylint: disable=unused-import
except Exception as e:
    PYFLINK_CYTHON_ENABLED = False
    _LOG.info("PYFLINK_CYTHON_ENABLED is set to False because of "
              "apache_beam.coders.stream import error: %s", str(e))


# Check whether PyFlink could be fast
try:
    from pyflink.fn_execution import stream_fast, coder_impl_fast \
        # noqa # pylint: disable=unused-import
    from pyflink.fn_execution.beam import \
        beam_operations_fast, beam_coder_impl_fast, beam_stream_fast \
        # noqa # pylint: disable=unused-import
    from pyflink.fn_execution.table import window_aggregate_fast, aggregate_fast \
        # noqa # pylint: disable=unused-import
except Exception as e:
    PYFLINK_CYTHON_ENABLED = False
    _LOG.info("PYFLINK_CYTHON_ENABLED is set to False because of "
              "pyflink cython extensions import error: %s", str(e))

_LOG.info("PYFLINK_CYTHON_ENABLED: %s", PYFLINK_CYTHON_ENABLED)