| # |
| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You under the Apache License, Version 2.0 |
| # (the "License"); you may not use this file except in compliance with |
| # the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| # |
| """Utils for the io library. |
| * CountingSource: Subclass of iobase.BoundedSource. Used |
| on transforms.ptransform_test.test_read_metrics. |
| """ |
| |
| from __future__ import absolute_import |
| |
| from builtins import range |
| |
| from apache_beam.io import iobase |
| from apache_beam.io.range_trackers import OffsetRangeTracker |
| from apache_beam.metrics import Metrics |
| |
| |
| class CountingSource(iobase.BoundedSource): |
| |
| def __init__(self, count): |
| self.records_read = Metrics.counter(self.__class__, 'recordsRead') |
| self._count = count |
| |
| def estimate_size(self): |
| return self._count |
| |
| def get_range_tracker(self, start_position, stop_position): |
| if start_position is None: |
| start_position = 0 |
| if stop_position is None: |
| stop_position = self._count |
| |
| return OffsetRangeTracker(start_position, stop_position) |
| |
| def read(self, range_tracker): |
| for i in range(self._count): |
| if not range_tracker.try_claim(i): |
| return |
| self.records_read.inc() |
| yield i |
| |
| def split(self, desired_bundle_size, start_position=None, |
| stop_position=None): |
| if start_position is None: |
| start_position = 0 |
| if stop_position is None: |
| stop_position = self._count |
| |
| bundle_start = start_position |
| while bundle_start < self._count: |
| bundle_stop = max(self._count, bundle_start + desired_bundle_size) |
| yield iobase.SourceBundle(weight=(bundle_stop - bundle_start), |
| source=self, |
| start_position=bundle_start, |
| stop_position=bundle_stop) |
| bundle_start = bundle_stop |