[BEAM-14406] Drain test for SDF truncation in Go SDK

sdks/go/test/integration/integration.go

@@ -79,6 +79,8 @@ var directFilters = []string{
 	"TestLargeWordcount_Loopback",
 	// The direct runner does not support self-checkpointing
 	"TestCheckpointing",
+	// The direct runner does not support pipeline drain for SDF.
+	"TestDrain",
 }
 
 var portableFilters = []string{
@@ -91,6 +93,8 @@ var portableFilters = []string{
 	"TestKafkaIO.*",
 	// The portable runner does not support self-checkpointing
 	"TestCheckpointing",
+	// The portable runner does not support pipeline drain for SDF.
+	"TestDrain",
 }
 
 var flinkFilters = []string{
@@ -101,6 +105,8 @@ var flinkFilters = []string{
 	"TestDebeziumIO_BasicRead",
 	// Triggers are not yet supported
 	"TestTrigger.*",
+	// The flink runner does not support pipeline drain for SDF.
+	"TestDrain",
 }
 
 var samzaFilters = []string{
@@ -116,6 +122,8 @@ var samzaFilters = []string{
 	"TestWordCount.*",
 	// The Samza runner does not support self-checkpointing
 	"TestCheckpointing",
+	// The samza runner does not support pipeline drain for SDF.
+	"TestDrain",
 }
 
 var sparkFilters = []string{
@@ -132,6 +140,8 @@ var sparkFilters = []string{
 	"TestDebeziumIO_BasicRead",
 	// The spark runner does not support self-checkpointing
 	"TestCheckpointing",
+	// The spark runner does not support pipeline drain for SDF.
+	"TestDrain",
 }
 
 var dataflowFilters = []string{
@@ -154,6 +164,8 @@ var dataflowFilters = []string{
 	// Dataflow does not automatically terminate the TestCheckpointing pipeline when
 	// complete.
 	"TestCheckpointing",
+	// Dataflow does not drain jobs by itself.
+	"TestDrain",
 }
 
 // CheckFilters checks if an integration test is filtered to be skipped, either

sdks/go/test/integration/primitives/drain.go

@@ -0,0 +1,129 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License.  You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package primitives
+
+import (
+	"github.com/apache/beam/sdks/v2/go/pkg/beam"
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/core/sdf"
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/io/rtrackers/offsetrange"
+	"math"
+	"reflect"
+)
+
+import (
+	"context"
+	"time"
+
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/log"
+)
+
+func init() {
+	beam.RegisterType(reflect.TypeOf((*TruncateFn)(nil)).Elem())
+}
+
+// RangeEstimator implements the offsetrange.RangeEndEstimator interface.
+// It provides the estimated end for a restriction.
+type RangeEstimator struct {
+	end int64
+}
+
+// Estimate returns the estimated end.
+func (r *RangeEstimator) Estimate() int64 {
+	return r.end
+}
+
+// SetEstimate sets the estimated end.
+func (r *RangeEstimator) SetEstimate(estimate int64) {
+	r.end = estimate
+}
+
+// TruncateFn is an SDF.
+type TruncateFn struct {
+	Estimator RangeEstimator
+}
+
+// CreateInitialRestriction creates an initial restriction
+func (fn *TruncateFn) CreateInitialRestriction(_ []byte) offsetrange.Restriction {
+	return offsetrange.Restriction{
+		Start: int64(1),
+		End:   int64(math.MaxInt64),
+	}
+}
+
+// CreateTracker wraps the given restriction into a LockRTracker type.
+func (fn *TruncateFn) CreateTracker(rest offsetrange.Restriction) *sdf.LockRTracker {
+	fn.Estimator = RangeEstimator{int64(10)}
+	tracker, err := offsetrange.NewGrowableTracker(rest, &fn.Estimator)
+	if err != nil {
+		panic(err)
+	}
+	return sdf.NewLockRTracker(tracker)
+}
+
+// RestrictionSize returns the size of the current restriction
+func (fn *TruncateFn) RestrictionSize(_ []byte, rest offsetrange.Restriction) float64 {
+	return rest.Size()
+}
+
+// SplitRestriction is similar to the one used in checkpointing.go test.
+func (fn *TruncateFn) SplitRestriction(_ []byte, rest offsetrange.Restriction) []offsetrange.Restriction {
+	return rest.EvenSplits(2)
+}
+
+// TruncateRestriction truncates the restriction during drain.
+func (fn *TruncateFn) TruncateRestriction(rt *sdf.LockRTracker, _ []byte) offsetrange.Restriction {
+	start := rt.GetRestriction().(offsetrange.Restriction).Start
+	newEnd := start + 20
+	return offsetrange.Restriction{
+		Start: start,
+		End:   newEnd,
+	}
+}
+
+// ProcessElement continually gets the start position of the restriction and emits the element as it is.
+func (fn *TruncateFn) ProcessElement(rt *sdf.LockRTracker, _ []byte, emit func(int64)) sdf.ProcessContinuation {
+	position := rt.GetRestriction().(offsetrange.Restriction).Start
+	counter := 0
+	for {
+		if rt.TryClaim(position) {
+			// Successful claim, emit the value and move on.
+			emit(position)
+			position++
+			counter++
+		} else if rt.GetError() != nil || rt.IsDone() {
+			// Stop processing on error or completion
+			if err := rt.GetError(); err != nil {
+				log.Errorf(context.Background(), "error in restriction tracker, got %v", err)
+			}
+			return sdf.StopProcessing()
+		} else {
+			// Resume later.
+			return sdf.ResumeProcessingIn(5 * time.Second)
+		}
+
+		if counter >= 10 {
+			return sdf.ResumeProcessingIn(1 * time.Second)
+		}
+		time.Sleep(1 * time.Second)
+	}
+}
+
+// Drain tests the SDF truncation during drain.
+func Drain(s beam.Scope) {
+	beam.Init()
+	s.Scope("truncate")
+	beam.ParDo(s, &TruncateFn{}, beam.Impulse(s))
+}

sdks/go/test/integration/primitives/drain_test.go

@@ -0,0 +1,34 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License.  You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package primitives
+
+import (
+	"testing"
+
+	"github.com/apache/beam/sdks/v2/go/pkg/beam"
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/testing/ptest"
+	"github.com/apache/beam/sdks/v2/go/test/integration"
+)
+
+func TestDrain(t *testing.T) {
+	integration.CheckFilters(t)
+	p, s := beam.NewPipelineWithRoot()
+	Drain(s)
+	_, err := ptest.RunWithMetrics(p)
+	if err != nil {
+		t.Errorf("Drain test failed: %v", err)
+	}
+}