[Feature]: Flat Converter from ewoks execution graph to ELK layout graph #17

[LudoBroche]

Tip

Description
Implements convert_ewoks_to_elk_graph, converting a flat ewoks TaskGraph into an ELK JSON layout graph (children with width/height, edges with sources/targets, and layoutOptions sourced from constants.py).

Closes #17

Note

Changes Made

• layout/elk_converter.py: convert_ewoks_to_elk_graph(ewoks_graph, task_sizes) -> ElkGraph.
• svg/svg_task_group.py: new SvgTaskGroup(SvgGroup) — SvgClass to group tasks together will allow to perform various operation on all the tasks. For example in this context extract all the tasks sizes.
• ewoksdraw/__init__.py: added build_svg_task_group(ewoks_graph) -> SvgTaskGroup, hiding the _get_all_node_inputs/_get_all_task_output_names node-to-SvgTask plumbing behind a single call.
• examples/convert_ewoks_to_elk_graph.py: runnable usage example.
• tests/test_elk_converter.py: unit tests covering top-level structure, children/task_sizes correspondence, single vs. multi data_mapping edges, empty graphs, counts across all ewokscore example graphs, and the task_sizes mismatch validation.

Warning

Note to Reviewer(s)

• Scope matches the issue: flat mapping only, no subworkflow expansion, no ELK solver invocation, no SVG rendering of the ELK result.
• ports were deliberately left out of scope — links are node-to-node, not port-to-port. This converter doesn't need it for layout purposes.
• task_sizes is a required, caller-supplied input rather than computed internally, so the ELK layout logic stays independent of the svg package.

[LudoBroche]

Running the example looks like that :

pixi run python examples/convert_ewoks_to_elk_graph.py

Ewoks Graph:

{'task1': {'default_inputs': [{'name': 'a', 'value': 1}],
           'task_identifier': 'ewokscore.tests.examples.tasks.condsumtask.CondSumTask',
           'task_type': 'class'},
 'task2': {'default_inputs': [{'name': 'b', 'value': 1}],
           'task_identifier': 'ewokscore.tests.examples.tasks.condsumtask.CondSumTask',
           'task_type': 'class'},
 'task3': {'default_inputs': [{'name': 'b', 'value': 1}],
           'task_identifier': 'ewokscore.tests.examples.tasks.condsumtask.CondSumTask',
           'task_type': 'class'}}
[('task1',
  'task2',
  {'conditions': [{'source_output': 'too_small', 'value': True}],
   'data_mapping': [{'source_output': 'result', 'target_input': 'a'}]}),
 ('task2',
  'task3',
  {'conditions': [{'source_output': 'too_small', 'value': True}],
   'data_mapping': [{'source_output': 'result', 'target_input': 'a'}]}),
 ('task3',
  'task1',
  {'conditions': [{'source_output': 'too_small', 'value': True}],
   'data_mapping': [{'source_output': 'result', 'target_input': 'a'}]})]

TaskSizes data structure:

{'task1': (54.232, 63.0), 'task2': (54.232, 63.0), 'task3': (54.232, 63.0)}

ELK Graph:

{'children': [{'height': 63.0, 'id': 'task1', 'width': 54.232},
              {'height': 63.0, 'id': 'task2', 'width': 54.232},
              {'height': 63.0, 'id': 'task3', 'width': 54.232}],
 'edges': [{'id': 'edge_task1_task2_0',
            'sources': ['task1'],
            'targets': ['task2']},
           {'id': 'edge_task2_task3_0',
            'sources': ['task2'],
            'targets': ['task3']},
           {'id': 'edge_task3_task1_0',
            'sources': ['task3'],
            'targets': ['task1']}],
 'id': 'root',
 'layoutOptions': {'elk.layered.edgeRouting.splines.mode': 'CONSERVATIVE_SOFT',
                   'org.eclipse.elk.algorithm': 'layered',
                   'org.eclipse.elk.direction': 'RIGHT',
                   'org.eclipse.elk.edgeRouting': 'SPLINES',
                   'org.eclipse.elk.layered.spacing.nodeNodeBetweenLayers': 80,
                   'org.eclipse.elk.spacing.edgeEdge': 20,
                   'org.eclipse.elk.spacing.nodeNode': 60}}

[codecov]

Codecov Report

❌ Patch coverage is 98.55072% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/ewoksdraw/svg/svg_task_group.py	96.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[loichuder]

First review round.

I don't understand how the introduction of SvgTaskGroup fits in the PR. Is it needed for the Elk layouting?

[loichuder]

Is there a usecase to access each constant individually?

If not, we could only have ELK_LAYOUT_OPTIONS as a constant.

[loichuder]

Nah.

[loichuder]

This would be way better if this was encoded in the type ElkGraph

[loichuder]

Suggested change

	n_mappings = len(link_attrs.get("data_mapping") or []) or 1
	n_mappings = len(link_attrs.get("data_mapping", [])) or 1

[loichuder]

It would be best to have a namedtuple instead of tuple[float, float] since it is very easy to confuse width and height if they are only addressed by their index.

[LudoBroche]

First review round.

I don't understand how the introduction of SvgTaskGroup fits in the PR. Is it needed for the Elk layouting?

Yes for the routing with ELK I need to have the sizes of eachs tasks box [{task_id:sizes},...].
I though the best API would be to do it from a tasks group class helper function.
Knowing also that in the future we will have to do more (i.e position all the taks correctly).