[Prism] Disable combiner lifting for TriggerAlways

sdks/go/pkg/beam/runners/prism/internal/handlecombine.go

@@ -64,43 +64,52 @@ func (h *combine) PrepareTransform(tid string, t *pipepb.PTransform, comps *pipe
 	combineInput := comps.GetPcollections()[onlyInput]
 	ws := comps.GetWindowingStrategies()[combineInput.GetWindowingStrategyId()]
 
-	var hasElementCount func(tpb *pipepb.Trigger) bool
+	var hasTriggerType func(tpb *pipepb.Trigger, targetTriggerType reflect.Type) bool
 
-	hasElementCount = func(tpb *pipepb.Trigger) bool {
-		elCount := false
+	hasTriggerType = func(tpb *pipepb.Trigger, targetTriggerType reflect.Type) bool {
+		if tpb == nil {
+			return false
+		}
 		switch at := tpb.GetTrigger().(type) {
-		case *pipepb.Trigger_ElementCount_:
-			return true
 		case *pipepb.Trigger_AfterAll_:
 			for _, st := range at.AfterAll.GetSubtriggers() {
-				elCount = elCount || hasElementCount(st)
+				if hasTriggerType(st, targetTriggerType) {
+					return true
+				}
 			}
-			return elCount
+			return false
 		case *pipepb.Trigger_AfterAny_:
 			for _, st := range at.AfterAny.GetSubtriggers() {
-				elCount = elCount || hasElementCount(st)
+				if hasTriggerType(st, targetTriggerType) {
+					return true
+				}
 			}
-			return elCount
+			return false
 		case *pipepb.Trigger_AfterEach_:
 			for _, st := range at.AfterEach.GetSubtriggers() {
-				elCount = elCount || hasElementCount(st)
+				if hasTriggerType(st, targetTriggerType) {
+					return true
+				}
 			}
-			return elCount
+			return false
 		case *pipepb.Trigger_AfterEndOfWindow_:
-			return hasElementCount(at.AfterEndOfWindow.GetEarlyFirings()) ||
-				hasElementCount(at.AfterEndOfWindow.GetLateFirings())
+			return hasTriggerType(at.AfterEndOfWindow.GetEarlyFirings(), targetTriggerType) ||
+				hasTriggerType(at.AfterEndOfWindow.GetLateFirings(), targetTriggerType)
 		case *pipepb.Trigger_OrFinally_:
-			return hasElementCount(at.OrFinally.GetMain()) ||
-				hasElementCount(at.OrFinally.GetFinally())
+			return hasTriggerType(at.OrFinally.GetMain(), targetTriggerType) ||
+				hasTriggerType(at.OrFinally.GetFinally(), targetTriggerType)
 		case *pipepb.Trigger_Repeat_:
-			return hasElementCount(at.Repeat.GetSubtrigger())
+			return hasTriggerType(at.Repeat.GetSubtrigger(), targetTriggerType)
 		default:
-			return false
+			return reflect.TypeOf(at) == targetTriggerType
 		}
 	}
 
 	// If we aren't lifting, the "default impl" for combines should be sufficient.
-	if !h.config.EnableLifting || hasElementCount(ws.GetTrigger()) {
+	// Disable lifting if there is any TriggerElementCount or TriggerAlways.
+	if (!h.config.EnableLifting ||
+		hasTriggerType(ws.GetTrigger(), reflect.TypeOf(&pipepb.Trigger_ElementCount_{})) ||
+		hasTriggerType(ws.GetTrigger(), reflect.TypeOf(&pipepb.Trigger_Always_{}))) {
 		return prepareResult{} // Strip the composite layer when lifting is disabled.
 	}
 

sdks/go/pkg/beam/runners/prism/internal/handlecombine_test.go

@@ -25,10 +25,14 @@ import (
 	"google.golang.org/protobuf/testing/protocmp"
 )
 
-func TestHandleCombine(t *testing.T) {
-	undertest := "UnderTest"
+func makeWindowingStrategy(trigger *pipepb.Trigger) *pipepb.WindowingStrategy {
+	return &pipepb.WindowingStrategy{
+		Trigger: trigger,
+	}
+}
 
-	combineTransform := &pipepb.PTransform{
+func makeCombineTransform(inputPCollectionID string) *pipepb.PTransform {
+	return &pipepb.PTransform{
 		UniqueName: "COMBINE",
 		Spec: &pipepb.FunctionSpec{
 			Urn: urns.TransformCombinePerKey,
@@ -41,7 +45,7 @@ func TestHandleCombine(t *testing.T) {
 			}),
 		},
 		Inputs: map[string]string{
-			"input": "combineIn",
+			"input": inputPCollectionID,
 		},
 		Outputs: map[string]string{
 			"input": "combineOut",
@@ -51,6 +55,15 @@ func TestHandleCombine(t *testing.T) {
 			"combine_values",
 		},
 	}
+}
+
+func TestHandleCombine(t *testing.T) {
+	undertest := "UnderTest"
+
+	combineTransform := makeCombineTransform("combineIn")
+	combineTransformWithTriggerElementCount := makeCombineTransform("combineInWithTriggerElementCount")
+	combineTransformWithTriggerAlways := makeCombineTransform("combineInWithTriggerAlways")
+
 	combineValuesTransform := &pipepb.PTransform{
 		UniqueName: "combine_values",
 		Subtransforms: []string{
@@ -64,6 +77,14 @@ func TestHandleCombine(t *testing.T) {
 		"combineOut": {
 			CoderId: "outputCoder",
 		},
+		"combineInWithTriggerElementCount": {
+			CoderId:             "inputCoder",
+			WindowingStrategyId: "wsElementCount",
+		},
+		"combineInWithTriggerAlways": {
+			CoderId:             "inputCoder",
+			WindowingStrategyId: "wsAlways",
+		},
 	}
 	baseCoderMap := map[string]*pipepb.Coder{
 		"int": {
@@ -84,7 +105,20 @@ func TestHandleCombine(t *testing.T) {
 			ComponentCoderIds: []string{"int", "string"},
 		},
 	}
-
+	baseWindowingStrategyMap := map[string]*pipepb.WindowingStrategy{
+		"wsElementCount": makeWindowingStrategy(&pipepb.Trigger{
+			Trigger: &pipepb.Trigger_ElementCount_{
+				ElementCount: &pipepb.Trigger_ElementCount{
+					ElementCount: 10,
+				},
+			},
+		}),
+		"wsAlways": makeWindowingStrategy(&pipepb.Trigger{
+			Trigger: &pipepb.Trigger_Always_{
+				Always: &pipepb.Trigger_Always{},
+			},
+		}),
+	}
 	tests := []struct {
 		name   string
 		lifted bool
@@ -188,6 +222,32 @@ func TestHandleCombine(t *testing.T) {
 					},
 				},
 			},
+		}, {
+			name:   "noLift_triggerElementCount",
+			lifted: true, // Lifting is enabled, but should be disabled in the present of the trigger
+			comps: &pipepb.Components{
+				Transforms: map[string]*pipepb.PTransform{
+					undertest:        combineTransformWithTriggerElementCount,
+					"combine_values": combineValuesTransform,
+				},
+				Pcollections:        basePCollectionMap,
+				Coders:              baseCoderMap,
+				WindowingStrategies: baseWindowingStrategyMap,
+			},
+			want: prepareResult{},
+		}, {
+			name:   "noLift_triggerAlways",
+			lifted: true, // Lifting is enabled, but should be disabled in the present of the trigger
+			comps: &pipepb.Components{
+				Transforms: map[string]*pipepb.PTransform{
+					undertest:        combineTransformWithTriggerAlways,
+					"combine_values": combineValuesTransform,
+				},
+				Pcollections:        basePCollectionMap,
+				Coders:              baseCoderMap,
+				WindowingStrategies: baseWindowingStrategyMap,
+			},
+			want: prepareResult{},
 		},
 	}
 	for _, test := range tests {

sdks/go/pkg/beam/runners/prism/internal/unimplemented_test.go

@@ -49,7 +49,6 @@ func TestUnimplemented(t *testing.T) {
 		// See https://github.com/apache/beam/issues/31153.
 		{pipeline: primitives.TriggerElementCount},
 		{pipeline: primitives.TriggerOrFinally},
-		{pipeline: primitives.TriggerAlways},
 
 		// Currently unimplemented triggers.
 		// https://github.com/apache/beam/issues/31438
@@ -87,6 +86,7 @@ func TestImplemented(t *testing.T) {
 		{pipeline: primitives.ParDoProcessElementBundleFinalizer},
 
 		{pipeline: primitives.TriggerNever},
+		{pipeline: primitives.TriggerAlways},
 		{pipeline: primitives.Panes},
 		{pipeline: primitives.TriggerAfterAll},
 		{pipeline: primitives.TriggerAfterAny},