Merge pull request #157 from scipp/prune-type-vars-v2

Prune type vars v2

src/ess/reduce/nexus/types.py

@@ -78,7 +78,17 @@ class TransmissionRun(Generic[ScatteringRunType]):
     TransmissionRun[BackgroundRun],
     VanadiumRun,
 )
-"""TypeVar used for specifying BackgroundRun, EmptyBeamRun or SampleRun"""
+"""TypeVar for specifying what run some data belongs to.
+
+Possible values:
+
+- :class:`BackgroundRun`
+- :class:`EmptyBeamRun`
+- :class:`SampleRun`
+- :class:`TransmissionRun`
+- :class:`VanadiumRun`
+"""
+
 
 # 1.2  Monitor types
 Monitor1 = NewType('Monitor1', int)
@@ -108,7 +118,20 @@ class TransmissionRun(Generic[ScatteringRunType]):
     IncidentMonitor,
     TransmissionMonitor,
 )
-"""TypeVar used for specifying the monitor type such as Incident or Transmission"""
+"""TypeVar for specifying what monitor some data belongs to.
+
+Possible values:
+
+- :class:`Monitor1`
+- :class:`Monitor2`
+- :class:`Monitor3`
+- :class:`Monitor4`
+- :class:`Monitor5`
+- :class:`Monitor6`
+- :class:`IncidentMonitor`
+- :class:`TransmissionMonitor`
+"""
+
 
 Component = TypeVar(
     'Component',

src/ess/reduce/nexus/workflow.py

@@ -3,12 +3,12 @@
 
 """Workflow and workflow components for interacting with NeXus files."""
 
-from collections.abc import Sequence
+from collections.abc import Iterable
 from copy import deepcopy
 from typing import Any
 
-import networkx as nx
 import sciline
+import sciline.typing
 import scipp as sc
 import scippnexus as snx
 from scipp.constants import g
@@ -649,30 +649,39 @@ def LoadDetectorWorkflow() -> sciline.Pipeline:
 
 def GenericNeXusWorkflow(
     *,
-    run_types: Sequence[sciline.typing.Key] | None = None,
-    monitor_types: Sequence[sciline.typing.Key] | None = None,
+    run_types: Iterable[sciline.typing.Key] | None = None,
+    monitor_types: Iterable[sciline.typing.Key] | None = None,
 ) -> sciline.Pipeline:
     """
     Generic workflow for loading detector and monitor data from a NeXus file.
 
+    It is possible to limit which run types and monitor types
+    are supported by the returned workflow.
+    This is useful to reduce the size of the workflow and make it easier to inspect.
+    Make sure to add *all* required run types and monitor types when using this feature.
+
+    Attention
+    ---------
+    Filtering by run type and monitor type does not work with nested type vars.
+    E.g., if you have a type like ``Outer[Inner[RunType]]``, this type and its
+    provider will be removed.
+
     Parameters
     ----------
     run_types:
         List of run types to include in the workflow. If not provided, all run types
-        are included. It is recommended to specify run types to avoid creating very
-        large workflows.
+        are included.
+        Must be a possible value of :class:`ess.reduce.nexus.types.RunType`.
     monitor_types:
         List of monitor types to include in the workflow. If not provided, all monitor
-        types are included. It is recommended to specify monitor types to avoid creating
-        very large workflows.
+        types are included.
+        Must be a possible value of :class:`ess.reduce.nexus.types.MonitorType`.
 
     Returns
     -------
     :
         The workflow.
     """
-    if monitor_types is not None and run_types is None:
-        raise ValueError("run_types must be specified if monitor_types is specified")
     wf = sciline.Pipeline(
         (
             *_common_providers,
@@ -685,16 +694,34 @@ def GenericNeXusWorkflow(
     wf[DetectorBankSizes] = DetectorBankSizes({})
     wf[PreopenNeXusFile] = PreopenNeXusFile(False)
 
-    g = wf.underlying_graph
-    ancestors = set()
-    # DetectorData and MonitorData are the "final" outputs, so finding and removing all
-    # their ancestors is what we need to strip unused run and monitor types.
-    for rt in run_types or ():
-        ancestors |= nx.ancestors(g, DetectorData[rt])
-        ancestors.add(DetectorData[rt])
-        for mt in monitor_types or ():
-            ancestors |= nx.ancestors(g, MonitorData[rt, mt])
-            ancestors.add(MonitorData[rt, mt])
-    if run_types is not None:
-        g.remove_nodes_from(set(g.nodes) - ancestors)
+    if run_types is not None or monitor_types is not None:
+        _prune_type_vars(wf, run_types=run_types, monitor_types=monitor_types)
+
     return wf
+
+
+def _prune_type_vars(
+    workflow: sciline.Pipeline,
+    *,
+    run_types: Iterable[sciline.typing.Key] | None,
+    monitor_types: Iterable[sciline.typing.Key] | None,
+) -> None:
+    # Remove all nodes that use a run type or monitor types that is
+    # not listed in the function arguments.
+    excluded_run_types = _excluded_type_args(RunType, run_types)
+    excluded_monitor_types = _excluded_type_args(MonitorType, monitor_types)
+    excluded_types = excluded_run_types | excluded_monitor_types
+
+    graph = workflow.underlying_graph
+    to_remove = [
+        node for node in graph if excluded_types & set(getattr(node, "__args__", set()))
+    ]
+    graph.remove_nodes_from(to_remove)
+
+
+def _excluded_type_args(
+    type_var: Any, keep: Iterable[sciline.typing.Key] | None
+) -> set[sciline.typing.Key]:
+    if keep is None:
+        return set()
+    return set(type_var.__constraints__) - set(keep)

tests/nexus/workflow_test.py

@@ -12,16 +12,20 @@
     BackgroundRun,
     Choppers,
     DetectorData,
+    EmptyBeamRun,
     Filename,
     Monitor1,
     Monitor2,
     Monitor3,
     MonitorData,
+    MonitorType,
     NeXusComponentLocationSpec,
     NeXusName,
     NeXusTransformation,
+    RunType,
     SampleRun,
     TimeInterval,
+    TransmissionMonitor,
 )
 from ess.reduce.nexus.workflow import (
     GenericNeXusWorkflow,
@@ -574,16 +578,11 @@ def test_generic_nexus_workflow_load_analyzers() -> None:
     assert analyzer['usage'] == 'Bragg'
 
 
-def test_generic_nexus_workflow_raises_if_monitor_types_but_not_run_types_given() -> (
-    None
-):
-    with pytest.raises(ValueError, match='run_types'):
-        GenericNeXusWorkflow(monitor_types=[Monitor1])
-
-
 def test_generic_nexus_workflow_includes_only_given_run_and_monitor_types() -> None:
     wf = GenericNeXusWorkflow(run_types=[SampleRun], monitor_types=[Monitor1, Monitor3])
     graph = wf.underlying_graph
+
+    # Check some examples to avoid relying entirely on complicated loops below.
     assert DetectorData[SampleRun] in graph
     assert DetectorData[BackgroundRun] not in graph
     assert MonitorData[SampleRun, Monitor1] in graph
@@ -592,7 +591,11 @@ def test_generic_nexus_workflow_includes_only_given_run_and_monitor_types() -> N
     assert MonitorData[BackgroundRun, Monitor1] not in graph
     assert MonitorData[BackgroundRun, Monitor2] not in graph
     assert MonitorData[BackgroundRun, Monitor3] not in graph
-    # Many other keys are also removed, this is just an example
+    assert Choppers[SampleRun] in graph
+    assert Choppers[BackgroundRun] not in graph
+    assert Analyzers[SampleRun] in graph
+    assert Analyzers[BackgroundRun] not in graph
+
     assert NeXusComponentLocationSpec[Monitor1, SampleRun] in graph
     assert NeXusComponentLocationSpec[Monitor2, SampleRun] not in graph
     assert NeXusComponentLocationSpec[Monitor3, SampleRun] in graph
@@ -605,3 +608,66 @@ def test_generic_nexus_workflow_includes_only_given_run_and_monitor_types() -> N
     assert NeXusComponentLocationSpec[snx.NXdetector, BackgroundRun] not in graph
     assert NeXusComponentLocationSpec[snx.NXsample, BackgroundRun] not in graph
     assert NeXusComponentLocationSpec[snx.NXsource, BackgroundRun] not in graph
+
+    excluded_run_types = set(RunType.__constraints__) - {SampleRun}
+    excluded_monitor_types = set(MonitorType.__constraints__) - {Monitor1, Monitor3}
+    for node in graph:
+        assert_not_contains_type_arg(node, excluded_run_types)
+        assert_not_contains_type_arg(node, excluded_monitor_types)
+
+
+def test_generic_nexus_workflow_includes_only_given_run_types() -> None:
+    wf = GenericNeXusWorkflow(run_types=[EmptyBeamRun])
+    graph = wf.underlying_graph
+
+    # Check some examples to avoid relying entirely on complicated loops below.
+    assert DetectorData[EmptyBeamRun] in graph
+    assert DetectorData[SampleRun] not in graph
+    assert MonitorData[EmptyBeamRun, Monitor1] in graph
+    assert MonitorData[EmptyBeamRun, Monitor2] in graph
+    assert MonitorData[EmptyBeamRun, Monitor3] in graph
+    assert MonitorData[SampleRun, Monitor1] not in graph
+    assert MonitorData[SampleRun, Monitor2] not in graph
+    assert MonitorData[SampleRun, Monitor3] not in graph
+    assert Choppers[EmptyBeamRun] in graph
+    assert Choppers[SampleRun] not in graph
+    assert Analyzers[EmptyBeamRun] in graph
+    assert Analyzers[SampleRun] not in graph
+
+    excluded_run_types = set(RunType.__constraints__) - {EmptyBeamRun}
+    for node in graph:
+        assert_not_contains_type_arg(node, excluded_run_types)
+
+
+def test_generic_nexus_workflow_includes_only_given_monitor_types() -> None:
+    wf = GenericNeXusWorkflow(monitor_types=[TransmissionMonitor, Monitor1])
+    graph = wf.underlying_graph
+
+    # Check some examples to avoid relying entirely on complicated loops below.
+    assert DetectorData[SampleRun] in graph
+    assert DetectorData[BackgroundRun] in graph
+    assert MonitorData[SampleRun, TransmissionMonitor] in graph
+    assert MonitorData[SampleRun, Monitor1] in graph
+    assert MonitorData[SampleRun, Monitor2] not in graph
+    assert MonitorData[SampleRun, Monitor3] not in graph
+    assert MonitorData[BackgroundRun, TransmissionMonitor] in graph
+    assert MonitorData[BackgroundRun, Monitor1] in graph
+    assert MonitorData[BackgroundRun, Monitor2] not in graph
+    assert MonitorData[BackgroundRun, Monitor3] not in graph
+    assert Choppers[SampleRun] in graph
+    assert Choppers[BackgroundRun] in graph
+    assert Analyzers[SampleRun] in graph
+    assert Analyzers[BackgroundRun] in graph
+
+    excluded_monitor_types = set(MonitorType.__constraints__) - {
+        Monitor1,
+        TransmissionMonitor,
+    }
+    for node in graph:
+        assert_not_contains_type_arg(node, excluded_monitor_types)
+
+
+def assert_not_contains_type_arg(node: object, excluded: set[type]) -> None:
+    assert not any(
+        arg in excluded for arg in getattr(node, "__args__", ())
+    ), f"Node {node} contains one of {excluded!r}"