Source code for taskflow.patterns.linear_flow

# -*- coding: utf-8 -*-

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#         http://www.apache.org/licenses/LICENSE-2.0
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#    Unless required by applicable law or agreed to in writing, software
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from taskflow import flow


_LINK_METADATA = {flow.LINK_INVARIANT: True}


[docs]class Flow(flow.Flow): """Linear flow pattern. A linear (potentially nested) flow of *tasks/flows* that can be applied in order as one unit and rolled back as one unit using the reverse order that the *tasks/flows* have been applied in. """ def __init__(self, name, retry=None): super(Flow, self).__init__(name, retry) self._children = []
[docs] def add(self, *items): """Adds a given task/tasks/flow/flows to this flow.""" items = [i for i in items if i not in self._children] self._children.extend(items) return self
def __len__(self): return len(self._children) def __iter__(self): for child in self._children: yield child @property def requires(self): requires = set() prior_provides = set() if self._retry is not None: requires.update(self._retry.requires) prior_provides.update(self._retry.provides) for item in self: requires.update(item.requires - prior_provides) prior_provides.update(item.provides) return frozenset(requires) def iter_links(self): for src, dst in zip(self._children[:-1], self._children[1:]): yield (src, dst, _LINK_METADATA.copy())