blob: 4654c90d20993bedf494e52e5068e4acf0437520 [file] [log] [blame]
#!/usr/bin/env python3
# -*- encoding: utf-8 -*-
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''' interface module for custom grouping'''
from abc import abstractmethod
class ICustomGrouping(object):
'''Interface for custom grouping class'''
def prepare(self, context, component, stream, target_tasks):
"""Tells the stream grouping at runtime the tasks in the target bolt
This information should be used in ``choose_tasks()`` to determine the target tasks.
:param context: topology-worker context
:param component: source component name
:param stream: stream id used for this grouping
:type target_tasks: list of int
:param target_tasks: list of target task ids
def choose_tasks(self, values):
"""Implements a custom stream grouping
:param values: the values to group on
:rtype: list of int
:return: list of task ids to which these values are emitted