#
# 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.
#
"""Module to condition how Interactive Beam stops capturing data.
For internal use only; no backwards-compatibility guarantees.
"""
import threading
import pandas as pd
from apache_beam.portability.api import beam_interactive_api_pb2
from apache_beam.portability.api import beam_runner_api_pb2
from apache_beam.runners.interactive import interactive_environment as ie
from apache_beam.utils.windowed_value import WindowedValue
[docs]class Limiter:
"""Limits an aspect of the caching layer."""
[docs] def is_triggered(self):
# type: () -> bool
"""Returns True if the limiter has triggered, and caching should stop."""
raise NotImplementedError
[docs]class ElementLimiter(Limiter):
"""A `Limiter` that limits reading from cache based on some property of an
element.
"""
[docs] def update(self, e):
# type: (Any) -> None # noqa: F821
"""Update the internal state based on some property of an element.
This is executed on every element that is read from cache.
"""
raise NotImplementedError
[docs]class SizeLimiter(Limiter):
"""Limits the cache size to a specified byte limit."""
def __init__(
self,
size_limit # type: int
):
self._size_limit = size_limit
[docs] def is_triggered(self):
total_capture_size = 0
ie.current_env().track_user_pipelines()
for user_pipeline in ie.current_env().tracked_user_pipelines:
cache_manager = ie.current_env().get_cache_manager(user_pipeline)
if hasattr(cache_manager, 'capture_size'):
total_capture_size += cache_manager.capture_size
return total_capture_size >= self._size_limit
[docs]class DurationLimiter(Limiter):
"""Limits the duration of the capture."""
def __init__(
self,
duration_limit # type: datetime.timedelta # noqa: F821
):
self._duration_limit = duration_limit
self._timer = threading.Timer(duration_limit.total_seconds(), self._trigger)
self._timer.daemon = True
self._triggered = False
self._timer.start()
def _trigger(self):
self._triggered = True
[docs] def is_triggered(self):
return self._triggered
[docs]class CountLimiter(ElementLimiter):
"""Limits by counting the number of elements seen."""
def __init__(self, max_count):
self._max_count = max_count
self._count = 0
[docs] def update(self, e):
# A TestStreamFileRecord can contain many elements at once. If e is a file
# record, then count the number of elements in the bundle.
if isinstance(e, beam_interactive_api_pb2.TestStreamFileRecord):
if not e.recorded_event.element_event:
return
self._count += len(e.recorded_event.element_event.elements)
# Otherwise, count everything else but the header of the file since it is
# not an element.
elif not isinstance(e, beam_interactive_api_pb2.TestStreamFileHeader):
# When elements are DataFrames, we want the output to be constrained by
# how many rows we have read, not how many DataFrames we have read.
if isinstance(e, WindowedValue) and isinstance(e.value, pd.DataFrame):
self._count += len(e.value)
else:
self._count += 1
[docs] def is_triggered(self):
return self._count >= self._max_count
[docs]class ProcessingTimeLimiter(ElementLimiter):
"""Limits by how long the ProcessingTime passed in the element stream.
Reads all elements from the timespan [start, start + duration).
This measures the duration from the first element in the stream. Each
subsequent element has a delta "advance_duration" that moves the internal
clock forward. This triggers when the duration from the internal clock and
the start exceeds the given duration.
"""
def __init__(self, max_duration_secs):
"""Initialize the ProcessingTimeLimiter."""
self._max_duration_us = max_duration_secs * 1e6
self._start_us = 0
self._cur_time_us = 0
[docs] def update(self, e):
# Only look at TestStreamFileRecords which hold the processing time.
if not isinstance(e, beam_runner_api_pb2.TestStreamPayload.Event):
return
if not e.HasField('processing_time_event'):
return
if self._start_us == 0:
self._start_us = e.processing_time_event.advance_duration
self._cur_time_us += e.processing_time_event.advance_duration
[docs] def is_triggered(self):
return self._cur_time_us - self._start_us >= self._max_duration_us