feat: Enable stream feature view materialization

go/internal/feast/featurestore.go

@@ -224,6 +224,14 @@ func (fs *FeatureStore) listAllViews() (map[string]*model.FeatureView, map[strin
 		fvs[featureView.Base.Name] = featureView
 	}
 
+	streamFeatureViews, err := fs.ListStreamFeatureViews()
+	if err != nil {
+		return nil, nil, err
+	}
+	for _, streamFeatureView := range streamFeatureViews {
+		fvs[streamFeatureView.Base.Name] = streamFeatureView
+	}
+
 	onDemandFeatureViews, err := fs.registry.ListOnDemandFeatureViews(fs.config.Project)
 	if err != nil {
 		return nil, nil, err
@@ -242,6 +250,14 @@ func (fs *FeatureStore) ListFeatureViews() ([]*model.FeatureView, error) {
 	return featureViews, nil
 }
 
+func (fs *FeatureStore) ListStreamFeatureViews() ([]*model.FeatureView, error) {
+	streamFeatureViews, err := fs.registry.ListStreamFeatureViews(fs.config.Project)
+	if err != nil {
+		return streamFeatureViews, err
+	}
+	return streamFeatureViews, nil
+}
+
 func (fs *FeatureStore) ListEntities(hideDummyEntity bool) ([]*model.Entity, error) {
 
 	allEntities, err := fs.registry.ListEntities(fs.config.Project)

go/internal/feast/model/featureview.go

@@ -24,7 +24,24 @@ type FeatureView struct {
 
 func NewFeatureViewFromProto(proto *core.FeatureView) *FeatureView {
 	featureView := &FeatureView{Base: NewBaseFeatureView(proto.Spec.Name, proto.Spec.Features),
-		Ttl: &(*proto.Spec.Ttl),
+		Ttl: proto.Spec.Ttl,
+	}
+	if len(proto.Spec.Entities) == 0 {
+		featureView.EntityNames = []string{DUMMY_ENTITY_NAME}
+	} else {
+		featureView.EntityNames = proto.Spec.Entities
+	}
+	entityColumns := make([]*Field, len(proto.Spec.EntityColumns))
+	for i, entityColumn := range proto.Spec.EntityColumns {
+		entityColumns[i] = NewFieldFromProto(entityColumn)
+	}
+	featureView.EntityColumns = entityColumns
+	return featureView
+}
+
+func NewFeatureViewFromStreamFeatureViewProto(proto *core.StreamFeatureView) *FeatureView {
+	featureView := &FeatureView{Base: NewBaseFeatureView(proto.Spec.Name, proto.Spec.Features),
+		Ttl: proto.Spec.Ttl,
 	}
 	if len(proto.Spec.Entities) == 0 {
 		featureView.EntityNames = []string{DUMMY_ENTITY_NAME}

go/internal/feast/registry/registry.go

@@ -30,6 +30,7 @@ type Registry struct {
 	cachedFeatureServices          map[string]map[string]*core.FeatureService
 	cachedEntities                 map[string]map[string]*core.Entity
 	cachedFeatureViews             map[string]map[string]*core.FeatureView
+	cachedStreamFeatureViews       map[string]map[string]*core.StreamFeatureView
 	cachedOnDemandFeatureViews     map[string]map[string]*core.OnDemandFeatureView
 	cachedRegistry                 *core.Registry
 	cachedRegistryProtoLastUpdated time.Time
@@ -106,10 +107,12 @@ func (r *Registry) load(registry *core.Registry) {
 	r.cachedFeatureServices = make(map[string]map[string]*core.FeatureService)
 	r.cachedEntities = make(map[string]map[string]*core.Entity)
 	r.cachedFeatureViews = make(map[string]map[string]*core.FeatureView)
+	r.cachedStreamFeatureViews = make(map[string]map[string]*core.StreamFeatureView)
 	r.cachedOnDemandFeatureViews = make(map[string]map[string]*core.OnDemandFeatureView)
 	r.loadEntities(registry)
 	r.loadFeatureServices(registry)
 	r.loadFeatureViews(registry)
+	r.loadStreamFeatureViews(registry)
 	r.loadOnDemandFeatureViews(registry)
 	r.cachedRegistryProtoLastUpdated = time.Now()
 }
@@ -144,6 +147,16 @@ func (r *Registry) loadFeatureViews(registry *core.Registry) {
 	}
 }
 
+func (r *Registry) loadStreamFeatureViews(registry *core.Registry) {
+	streamFeatureViews := registry.StreamFeatureViews
+	for _, streamFeatureView := range streamFeatureViews {
+		if _, ok := r.cachedStreamFeatureViews[streamFeatureView.Spec.Project]; !ok {
+			r.cachedStreamFeatureViews[streamFeatureView.Spec.Project] = make(map[string]*core.StreamFeatureView)
+		}
+		r.cachedStreamFeatureViews[streamFeatureView.Spec.Project][streamFeatureView.Spec.Name] = streamFeatureView
+	}
+}
+
 func (r *Registry) loadOnDemandFeatureViews(registry *core.Registry) {
 	onDemandFeatureViews := registry.OnDemandFeatureViews
 	for _, onDemandFeatureView := range onDemandFeatureViews {
@@ -193,7 +206,26 @@ func (r *Registry) ListFeatureViews(project string) ([]*model.FeatureView, error
 }
 
 /*
-	Look up Feature Views inside project
+	Look up Stream Feature Views inside project
+	Returns empty list if project not found
+*/
+
+func (r *Registry) ListStreamFeatureViews(project string) ([]*model.FeatureView, error) {
+	if cachedStreamFeatureViews, ok := r.cachedStreamFeatureViews[project]; !ok {
+		return []*model.FeatureView{}, nil
+	} else {
+		streamFeatureViews := make([]*model.FeatureView, len(cachedStreamFeatureViews))
+		index := 0
+		for _, streamFeatureViewProto := range cachedStreamFeatureViews {
+			streamFeatureViews[index] = model.NewFeatureViewFromStreamFeatureViewProto(streamFeatureViewProto)
+			index += 1
+		}
+		return streamFeatureViews, nil
+	}
+}
+
+/*
+	Look up Feature Services inside project
 	Returns empty list if project not found
 */
 
@@ -254,6 +286,18 @@ func (r *Registry) GetFeatureView(project, featureViewName string) (*model.Featu
 	}
 }
 
+func (r *Registry) GetStreamFeatureView(project, streamFeatureViewName string) (*model.FeatureView, error) {
+	if cachedStreamFeatureViews, ok := r.cachedStreamFeatureViews[project]; !ok {
+		return nil, fmt.Errorf("no cached stream feature views found for project %s", project)
+	} else {
+		if streamFeatureViewProto, ok := cachedStreamFeatureViews[streamFeatureViewName]; !ok {
+			return nil, fmt.Errorf("no cached stream feature view %s found for project %s", streamFeatureViewName, project)
+		} else {
+			return model.NewFeatureViewFromStreamFeatureViewProto(streamFeatureViewProto), nil
+		}
+	}
+}
+
 func (r *Registry) GetFeatureService(project, featureServiceName string) (*model.FeatureService, error) {
 	if cachedFeatureServices, ok := r.cachedFeatureServices[project]; !ok {
 		return nil, fmt.Errorf("no cached feature services found for project %s", project)

sdk/python/feast/feature_store.py

@@ -265,6 +265,19 @@ def _list_feature_views(
             feature_views.append(fv)
         return feature_views
 
+    def _list_stream_feature_views(
+        self, allow_cache: bool = False, hide_dummy_entity: bool = True,
+    ) -> List[StreamFeatureView]:
+        stream_feature_views = []
+        for sfv in self._registry.list_stream_feature_views(
+            self.project, allow_cache=allow_cache
+        ):
+            if hide_dummy_entity and sfv.entities[0] == DUMMY_ENTITY_NAME:
+                sfv.entities = []
+                sfv.entity_columns = []
+            stream_feature_views.append(sfv)
+        return stream_feature_views
+
     @log_exceptions_and_usage
     def list_on_demand_feature_views(
         self, allow_cache: bool = False
@@ -289,9 +302,7 @@ def list_stream_feature_views(
         Returns:
             A list of stream feature views.
         """
-        return self._registry.list_stream_feature_views(
-            self.project, allow_cache=allow_cache
-        )
+        return self._list_stream_feature_views(allow_cache)
 
     @log_exceptions_and_usage
     def list_data_sources(self, allow_cache: bool = False) -> List[DataSource]:
@@ -558,6 +569,9 @@ def _make_inferences(
         update_feature_views_with_inferred_features_and_entities(
             views_to_update, entities + entities_to_update, self.config
         )
+        update_feature_views_with_inferred_features_and_entities(
+            sfvs_to_update, entities + entities_to_update, self.config
+        )
         # TODO(kevjumba): Update schema inferrence
         for sfv in sfvs_to_update:
             if not sfv.schema:
@@ -574,6 +588,53 @@ def _make_inferences(
         for feature_service in feature_services_to_update:
             feature_service.infer_features(fvs_to_update=fvs_to_update_map)
 
+    def _get_feature_views_to_materialize(
+        self, feature_views: Optional[List[str]],
+    ) -> List[FeatureView]:
+        """
+        Returns the list of feature views that should be materialized.
+
+        If no feature views are specified, all feature views will be returned.
+
+        Args:
+            feature_views: List of names of feature views to materialize.
+
+        Raises:
+            FeatureViewNotFoundException: One of the specified feature views could not be found.
+            ValueError: One of the specified feature views is not configured for materialization.
+        """
+        feature_views_to_materialize: List[FeatureView] = []
+
+        if feature_views is None:
+            feature_views_to_materialize = self._list_feature_views(
+                hide_dummy_entity=False
+            )
+            feature_views_to_materialize = [
+                fv for fv in feature_views_to_materialize if fv.online
+            ]
+            stream_feature_views_to_materialize = self._list_stream_feature_views(
+                hide_dummy_entity=False
+            )
+            feature_views_to_materialize += [
+                sfv for sfv in stream_feature_views_to_materialize if sfv.online
+            ]
+        else:
+            for name in feature_views:
+                try:
+                    feature_view = self._get_feature_view(name, hide_dummy_entity=False)
+                except FeatureViewNotFoundException:
+                    feature_view = self._get_stream_feature_view(
+                        name, hide_dummy_entity=False
+                    )
+
+                if not feature_view.online:
+                    raise ValueError(
+                        f"FeatureView {feature_view.name} is not configured to be served online."
+                    )
+                feature_views_to_materialize.append(feature_view)
+
+        return feature_views_to_materialize
+
     @log_exceptions_and_usage
     def _plan(
         self, desired_repo_contents: RepoContents
@@ -873,8 +934,8 @@ def apply(
 
         self._get_provider().update_infra(
             project=self.project,
-            tables_to_delete=views_to_delete if not partial else [],
-            tables_to_keep=views_to_update,
+            tables_to_delete=views_to_delete + sfvs_to_delete if not partial else [],
+            tables_to_keep=views_to_update + sfvs_to_update,
             entities_to_delete=entities_to_delete if not partial else [],
             entities_to_keep=entities_to_update,
             partial=partial,
@@ -1151,23 +1212,9 @@ def materialize_incremental(
             <BLANKLINE>
             ...
         """
-        feature_views_to_materialize: List[FeatureView] = []
-        if feature_views is None:
-            feature_views_to_materialize = self._list_feature_views(
-                hide_dummy_entity=False
-            )
-            feature_views_to_materialize = [
-                fv for fv in feature_views_to_materialize if fv.online
-            ]
-        else:
-            for name in feature_views:
-                feature_view = self._get_feature_view(name, hide_dummy_entity=False)
-                if not feature_view.online:
-                    raise ValueError(
-                        f"FeatureView {feature_view.name} is not configured to be served online."
-                    )
-                feature_views_to_materialize.append(feature_view)
-
+        feature_views_to_materialize = self._get_feature_views_to_materialize(
+            feature_views
+        )
         _print_materialization_log(
             None,
             end_date,
@@ -1258,23 +1305,9 @@ def materialize(
                 f"The given start_date {start_date} is greater than the given end_date {end_date}."
             )
 
-        feature_views_to_materialize: List[FeatureView] = []
-        if feature_views is None:
-            feature_views_to_materialize = self._list_feature_views(
-                hide_dummy_entity=False
-            )
-            feature_views_to_materialize = [
-                fv for fv in feature_views_to_materialize if fv.online
-            ]
-        else:
-            for name in feature_views:
-                feature_view = self._get_feature_view(name, hide_dummy_entity=False)
-                if not feature_view.online:
-                    raise ValueError(
-                        f"FeatureView {feature_view.name} is not configured to be served online."
-                    )
-                feature_views_to_materialize.append(feature_view)
-
+        feature_views_to_materialize = self._get_feature_views_to_materialize(
+            feature_views
+        )
         _print_materialization_log(
             start_date,
             end_date,
@@ -1327,6 +1360,7 @@ def push(
         from feast.data_source import PushSource
 
         all_fvs = self.list_feature_views(allow_cache=allow_registry_cache)
+        all_fvs += self.list_stream_feature_views(allow_cache=allow_registry_cache)
 
         fvs_with_push_sources = {
             fv

sdk/python/feast/inference.py

@@ -99,6 +99,10 @@ def update_feature_views_with_inferred_features_and_entities(
     other columns except designated timestamp columns are considered to be feature columns. If
     the feature view already has features, feature inference is skipped.
 
+    Note that this inference logic currently does not take any transformations (either a UDF or
+    aggregations) into account. For example, even if a stream feature view has a transformation,
+    this method assumes that the batch source contains transformed data with the correct final schema.
+
     Args:
         fvs: The feature views to be updated.
         entities: A list containing entities associated with the feature views.

sdk/python/feast/registry.py

@@ -1267,6 +1267,30 @@ def apply_materialization(
                     self.commit()
                 return
 
+        for idx, existing_stream_feature_view_proto in enumerate(
+            self.cached_registry_proto.stream_feature_views
+        ):
+            if (
+                existing_stream_feature_view_proto.spec.name == feature_view.name
+                and existing_stream_feature_view_proto.spec.project == project
+            ):
+                existing_stream_feature_view = StreamFeatureView.from_proto(
+                    existing_stream_feature_view_proto
+                )
+                existing_stream_feature_view.materialization_intervals.append(
+                    (start_date, end_date)
+                )
+                existing_stream_feature_view.last_updated_timestamp = datetime.utcnow()
+                stream_feature_view_proto = existing_stream_feature_view.to_proto()
+                stream_feature_view_proto.spec.project = project
+                del self.cached_registry_proto.stream_feature_views[idx]
+                self.cached_registry_proto.stream_feature_views.append(
+                    stream_feature_view_proto
+                )
+                if commit:
+                    self.commit()
+                return
+
         raise FeatureViewNotFoundException(feature_view.name, project)
 
     def list_feature_views(