loki.batch.sgraph

Classes

SGraph()

The dependency graph underpinning the Scheduler
class SGraph

Bases: object

The dependency graph underpinning the Scheduler

It is built upon a networkx.DiGraph to expose the dependencies between Item nodes. It is typically created from one or multiple seed items via from_seed() by recursively chasing dependencies.

Cyclic dependencies are broken for procedures that are marked as RECURSIVE, which would otherwise constitute a dependency on itself. See _break_cycles().

classmethod from_seed(seed, item_factory, config=None)

Create a new SGraph using seed as starting point.

Parameters:

  • seed ((list of) str) – The names of the root nodes

  • item_factory (ItemFactory) – The item factory to use when creating graph nodes

  • config (SchedulerConfig, optional) – The config object to use when creating items

as_filegraph(item_factory, config=None, item_filter=None, exclude_ignored=False)

Convert the SGraph to a dependency graph that only contains FileItem nodes.

Parameters:

  • item_factory (ItemFactory) – The item factory to use when creating graph nodes

  • config (SchedulerConfig, optional) – The config object to use when creating items

  • item_filter (list of Item subclasses, optional) – Only include files that include at least one dependency item of the given type. By default, all items are included.

  • exclude_ignored (bool, optional) – Exclude Item`s that have the ``is_ignored` property

Returns:

A new graph object

Return type:

SGraph

property items

Return all Item nodes in the dependency graph

property dependencies

Return all dependencies, i.e., edges of the dependency graph

successors(item, item_filter=None)

Return the list of successor nodes in the dependency tree below Item

This returns all immediate successors (but can be filtered accordingly using the item’s targets property) of the item in the dependency graph

The list of successors is provided to transformations during processing with the Scheduler.

Parameters:

  • item (Item) – The item node in the dependency graph for which to determine the successors

  • item_filter (list of Item subclasses, optional) – Filter successor items to only include items of the provided type. By default, all items are considered. Note that including ProcedureItem in the item_filter automatically adds ProcedureBindingItem and InterfaceItem as well, since these are intermediate nodes. Their dependencies will also be included until they eventually resolve to a ProcedureItem.

property depths

Return a mapping of Item nodes to their depth (topological generation) in the dependency graph

add_node(item)

Add item as a node to the dependency graph

add_nodes(items)

Add the given items as nodes to the dependency graph

add_edge(edge)

Add a dependency edge to the dependency graph

add_edges(edges)

Add the dependency edges to the dependency graph

export_to_file(dotfile_path)

Generate a dotfile from the current graph

Parameters:

dotfile_path (str or pathlib.Path) – Path to write the dotfile to. A corresponding graphical representation will be created with an additional .pdf appendix.