| /* |
| * 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 org.apache.beam.sdk.io.gcp.pubsublite; |
| |
| import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument; |
| |
| import com.google.cloud.pubsublite.Partition; |
| import com.google.cloud.pubsublite.PartitionLookupUtils; |
| import com.google.cloud.pubsublite.SubscriptionPath; |
| import com.google.cloud.pubsublite.TopicPath; |
| import java.util.List; |
| import java.util.stream.Collectors; |
| import java.util.stream.IntStream; |
| import org.apache.beam.sdk.transforms.Create; |
| import org.apache.beam.sdk.transforms.MapElements; |
| import org.apache.beam.sdk.transforms.PTransform; |
| import org.apache.beam.sdk.transforms.SerializableFunction; |
| import org.apache.beam.sdk.transforms.Watch; |
| import org.apache.beam.sdk.transforms.Watch.Growth.PollFn; |
| import org.apache.beam.sdk.transforms.Watch.Growth.PollResult; |
| import org.apache.beam.sdk.values.KV; |
| import org.apache.beam.sdk.values.PBegin; |
| import org.apache.beam.sdk.values.PCollection; |
| import org.apache.beam.sdk.values.TypeDescriptor; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList; |
| import org.joda.time.Duration; |
| import org.joda.time.Instant; |
| |
| class SubscriptionPartitionLoader extends PTransform<PBegin, PCollection<SubscriptionPartition>> { |
| private final TopicPath topic; |
| private final SubscriptionPath subscription; |
| private final SerializableFunction<TopicPath, Integer> getPartitionCount; |
| private final Duration pollDuration; |
| private final boolean terminate; |
| |
| SubscriptionPartitionLoader(TopicPath topic, SubscriptionPath subscription) { |
| this( |
| topic, |
| subscription, |
| PartitionLookupUtils::numPartitions, |
| Duration.standardMinutes(1), |
| false); |
| } |
| |
| @VisibleForTesting |
| SubscriptionPartitionLoader( |
| TopicPath topic, |
| SubscriptionPath subscription, |
| SerializableFunction<TopicPath, Integer> getPartitionCount, |
| Duration pollDuration, |
| boolean terminate) { |
| this.topic = topic; |
| this.subscription = subscription; |
| this.getPartitionCount = getPartitionCount; |
| this.pollDuration = pollDuration; |
| this.terminate = terminate; |
| } |
| |
| @Override |
| public PCollection<SubscriptionPartition> expand(PBegin input) { |
| PCollection<TopicPath> start = input.apply(Create.of(ImmutableList.of(topic))); |
| PCollection<KV<TopicPath, Partition>> partitions = |
| start.apply( |
| Watch.growthOf( |
| new PollFn<TopicPath, Partition>() { |
| @Override |
| public PollResult<Partition> apply(TopicPath element, Context c) { |
| checkArgument(element.equals(topic)); |
| int partitionCount = getPartitionCount.apply(element); |
| List<Partition> partitions = |
| IntStream.range(0, partitionCount) |
| .mapToObj(Partition::of) |
| .collect(Collectors.toList()); |
| return PollResult.incomplete(Instant.now(), partitions); |
| } |
| }) |
| .withPollInterval(pollDuration) |
| .withTerminationPerInput( |
| terminate ? Watch.Growth.afterIterations(10) : Watch.Growth.never())); |
| return partitions.apply( |
| MapElements.into(TypeDescriptor.of(SubscriptionPartition.class)) |
| .via(kv -> SubscriptionPartition.of(subscription, kv.getValue()))); |
| } |
| } |