blob: 3af381d5005e52e3ee32aa077bd25faa78c8e9ed [file] [log] [blame]
#!/usr/bin/env python3
# -*- encoding: utf-8 -*-
# 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
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# under the License.
"""module for flat_map bolt: FlatMapBolt"""
import collections
from heronpy.api.bolt.bolt import Bolt
from heronpy.api.state.stateful_component import StatefulComponent
from heronpy.api.component.component_spec import GlobalStreamId
from heronpy.api.stream import Grouping
from heronpy.streamlet.streamlet import Streamlet
from heronpy.streamlet.impl.streamletboltbase import StreamletBoltBase
# pylint: disable=unused-argument
class FlatMapBolt(Bolt, StatefulComponent, StreamletBoltBase):
"""FlatMapBolt"""
FUNCTION = 'function'
def init_state(self, stateful_state):
# flat_map does not have any state
pass
def pre_save(self, checkpoint_id):
# flat_map does not have any state
pass
def initialize(self, config, context):
self.logger.debug("FlatMapBolt's Component-specific config: \n%s" % str(config))
self.processed = 0
self.emitted = 0
if FlatMapBolt.FUNCTION in config:
self.flatmap_function = config[FlatMapBolt.FUNCTION]
else:
raise RuntimeError("FlatMapBolt needs to be passed flat_map function")
def process(self, tup):
retval = self.flatmap_function(tup.values[0])
if isinstance(retval, collections.Iterable):
for value in retval:
self.emit([value], stream='output')
self.emitted += 1
else:
self.emit([retval], stream='output')
self.emitted += 1
self.processed += 1
self.ack(tup)
# pylint: disable=protected-access
class FlatMapStreamlet(Streamlet):
"""FlatMapStreamlet"""
def __init__(self, flatmap_function, parent):
super(FlatMapStreamlet, self).__init__()
if not callable(flatmap_function):
raise RuntimeError("FlatMap function has to be callable")
if not isinstance(parent, Streamlet):
raise RuntimeError("Parent of FlatMap Streamlet has to be a Streamlet")
self._parent = parent
self._flatmap_function = flatmap_function
self.set_num_partitions(parent.get_num_partitions())
def _calculate_inputs(self):
return {GlobalStreamId(self._parent.get_name(), self._parent._output) :
Grouping.SHUFFLE}
def _build_this(self, builder, stage_names):
if not self.get_name():
self.set_name(self._default_stage_name_calculator("flatmap", stage_names))
if self.get_name() in stage_names:
raise RuntimeError("Duplicate Names")
stage_names.add(self.get_name())
builder.add_bolt(self.get_name(), FlatMapBolt, par=self.get_num_partitions(),
inputs=self._calculate_inputs(),
config={FlatMapBolt.FUNCTION : self._flatmap_function})
return True