Foundations for custom granularity (#1388)

A few small changes that will be used in the dataflow plan for custom
granularities. Mostly some small cleanup items (detailed in commit
messages). Also adds a custom granularity called `martian_day` to the
daily time spine. This increments one day for every thousand days. Not
my decision. That's just how the martians do it. 👽

metricflow-semantics/metricflow_semantics/model/semantics/linkable_spec_resolver.py

@@ -126,7 +126,7 @@ def __init__(
         # Sort semantic models by name for consistency in building derived objects.
         self._semantic_models = sorted(self._semantic_manifest.semantic_models, key=lambda x: x.name)
         self._join_evaluator = SemanticModelJoinEvaluator(semantic_model_lookup)
-        self._time_spine_sources = TimeSpineSource.create_from_manifest(self._semantic_manifest)
+        self._time_spine_sources = TimeSpineSource.build_standard_time_spine_sources(self._semantic_manifest)
 
         assert max_entity_links >= 0
         self._max_entity_links = max_entity_links

metricflow-semantics/metricflow_semantics/specs/time_dimension_spec.py

@@ -154,6 +154,17 @@ def with_grain(self, time_granularity: ExpandedTimeGranularity) -> TimeDimension
             aggregation_state=self.aggregation_state,
         )
 
+    def with_grain_and_date_part(  # noqa: D102
+        self, time_granularity: ExpandedTimeGranularity, date_part: Optional[DatePart]
+    ) -> TimeDimensionSpec:
+        return TimeDimensionSpec(
+            element_name=self.element_name,
+            entity_links=self.entity_links,
+            time_granularity=time_granularity,
+            date_part=date_part,
+            aggregation_state=self.aggregation_state,
+        )
+
     def with_aggregation_state(self, aggregation_state: AggregationState) -> TimeDimensionSpec:  # noqa: D102
         return TimeDimensionSpec(
             element_name=self.element_name,

metricflow-semantics/metricflow_semantics/test_helpers/semantic_manifest_yamls/shared/project_configuration.yaml

@@ -42,3 +42,11 @@ project_configuration:
       primary_column:
         name: ts
         time_granularity: hour
+    - node_relation:
+        alias: mf_time_spine
+        schema_name: $source_schema
+      primary_column:
+        name: ds
+        time_granularity: day
+      custom_granularities:
+        - name: martian_day

metricflow-semantics/metricflow_semantics/time/time_spine_source.py

@@ -29,15 +29,17 @@ class TimeSpineSource:
     # The time granularity of the base column.
     base_granularity: TimeGranularity = DEFAULT_TIME_GRANULARITY
     db_name: Optional[str] = None
-    custom_granularity_columns: Sequence[str] = ()
+    custom_granularities: Sequence[str] = ()
 
     @property
     def spine_table(self) -> SqlTable:
         """Table containing all dates."""
         return SqlTable(schema_name=self.schema_name, table_name=self.table_name, db_name=self.db_name)
 
     @staticmethod
-    def create_from_manifest(semantic_manifest: SemanticManifest) -> Dict[TimeGranularity, TimeSpineSource]:
+    def build_standard_time_spine_sources(
+        semantic_manifest: SemanticManifest,
+    ) -> Dict[TimeGranularity, TimeSpineSource]:
         """Creates a time spine source based on what's in the manifest."""
         time_spine_sources = {
             time_spine.primary_column.time_granularity: TimeSpineSource(
@@ -46,7 +48,7 @@ def create_from_manifest(semantic_manifest: SemanticManifest) -> Dict[TimeGranul
                 db_name=time_spine.node_relation.database,
                 base_column=time_spine.primary_column.name,
                 base_granularity=time_spine.primary_column.time_granularity,
-                custom_granularity_columns=[column.name for column in time_spine.custom_granularities],
+                custom_granularities=[column.name for column in time_spine.custom_granularities],
             )
             for time_spine in semantic_manifest.project_configuration.time_spines
         }

metricflow/dataflow/builder/source_node.py

@@ -60,7 +60,7 @@ def __init__(  # noqa: D107
         self._semantic_manifest_lookup = semantic_manifest_lookup
         data_set_converter = SemanticModelToDataSetConverter(column_association_resolver)
         self._time_spine_source_nodes = {}
-        for granularity, time_spine_source in TimeSpineSource.create_from_manifest(
+        for granularity, time_spine_source in TimeSpineSource.build_standard_time_spine_sources(
             semantic_manifest_lookup.semantic_manifest
         ).items():
             data_set = data_set_converter.build_time_spine_source_data_set(time_spine_source)

metricflow/engine/metricflow_engine.py

@@ -366,7 +366,9 @@ def __init__(
             DunderColumnAssociationResolver(semantic_manifest_lookup)
         )
         self._time_source = time_source
-        self._time_spine_sources = TimeSpineSource.create_from_manifest(semantic_manifest_lookup.semantic_manifest)
+        self._time_spine_sources = TimeSpineSource.build_standard_time_spine_sources(
+            semantic_manifest_lookup.semantic_manifest
+        )
         self._source_data_sets: List[SemanticModelDataSet] = []
         converter = SemanticModelToDataSetConverter(column_association_resolver=self._column_association_resolver)
         for semantic_model in sorted(

metricflow/plan_conversion/dataflow_to_sql.py

@@ -38,7 +38,6 @@
 from metricflow_semantics.specs.metadata_spec import MetadataSpec
 from metricflow_semantics.specs.metric_spec import MetricSpec
 from metricflow_semantics.specs.spec_set import InstanceSpecSet
-from metricflow_semantics.specs.time_dimension_spec import TimeDimensionSpec
 from metricflow_semantics.sql.sql_join_type import SqlJoinType
 from metricflow_semantics.time.time_constants import ISO8601_PYTHON_FORMAT, ISO8601_PYTHON_TS_FORMAT
 from metricflow_semantics.time.time_spine_source import TIME_SPINE_DATA_SET_DESCRIPTION, TimeSpineSource
@@ -196,7 +195,9 @@ def __init__(
         self._semantic_manifest_lookup = semantic_manifest_lookup
         self._metric_lookup = semantic_manifest_lookup.metric_lookup
         self._semantic_model_lookup = semantic_manifest_lookup.semantic_model_lookup
-        self._time_spine_sources = TimeSpineSource.create_from_manifest(semantic_manifest_lookup.semantic_manifest)
+        self._time_spine_sources = TimeSpineSource.build_standard_time_spine_sources(
+            semantic_manifest_lookup.semantic_manifest
+        )
 
     @property
     def column_association_resolver(self) -> ColumnAssociationResolver:  # noqa: D102
@@ -1408,12 +1409,8 @@ def visit_join_to_time_spine_node(self, node: JoinToTimeSpineNode) -> SqlDataSet
             # Apply date_part to time spine column select expression.
             if time_dimension_spec.date_part:
                 select_expr = SqlExtractExpression.create(date_part=time_dimension_spec.date_part, arg=select_expr)
-            time_dim_spec = TimeDimensionSpec(
-                element_name=original_time_spine_dim_instance.spec.element_name,
-                entity_links=original_time_spine_dim_instance.spec.entity_links,
-                time_granularity=time_dimension_spec.time_granularity,
-                date_part=time_dimension_spec.date_part,
-                aggregation_state=original_time_spine_dim_instance.spec.aggregation_state,
+            time_dim_spec = original_time_spine_dim_instance.spec.with_grain_and_date_part(
+                time_granularity=time_dimension_spec.time_granularity, date_part=time_dimension_spec.date_part
             )
             time_spine_dim_instance = TimeDimensionInstance(
                 defined_from=original_time_spine_dim_instance.defined_from,