org.apache.kafka.streams.state.internals.StreamThreadStateStoreProvider Maven / Gradle / Ivy
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* 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
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* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* limitations under the License.
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package org.apache.kafka.streams.state.internals;
import org.apache.kafka.streams.StoreQueryParameters;
import org.apache.kafka.streams.errors.InvalidStateStoreException;
import org.apache.kafka.streams.processor.StateStore;
import org.apache.kafka.streams.processor.TaskId;
import org.apache.kafka.streams.processor.internals.StreamThread;
import org.apache.kafka.streams.processor.internals.Task;
import org.apache.kafka.streams.processor.internals.namedtopology.NamedTopologyStoreQueryParameters;
import org.apache.kafka.streams.state.QueryableStoreType;
import org.apache.kafka.streams.state.QueryableStoreTypes;
import org.apache.kafka.streams.state.TimestampedKeyValueStore;
import org.apache.kafka.streams.state.TimestampedWindowStore;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
public class StreamThreadStateStoreProvider {
private final StreamThread streamThread;
public StreamThreadStateStoreProvider(final StreamThread streamThread) {
this.streamThread = streamThread;
}
@SuppressWarnings("unchecked")
public List stores(final StoreQueryParameters storeQueryParams) {
final StreamThread.State state = streamThread.state();
if (state == StreamThread.State.DEAD) {
return Collections.emptyList();
}
final String storeName = storeQueryParams.storeName();
final QueryableStoreType queryableStoreType = storeQueryParams.queryableStoreType();
final String topologyName = storeQueryParams instanceof NamedTopologyStoreQueryParameters ?
((NamedTopologyStoreQueryParameters) storeQueryParams).topologyName() :
null;
if (storeQueryParams.staleStoresEnabled() ? state.isAlive() : state == StreamThread.State.RUNNING) {
final Collection tasks = storeQueryParams.staleStoresEnabled() ?
streamThread.readyOnlyAllTasks() : streamThread.readOnlyActiveTasks();
if (storeQueryParams.partition() != null) {
for (final Task task : tasks) {
if (task.id().partition() == storeQueryParams.partition() &&
(topologyName == null || topologyName.equals(task.id().topologyName())) &&
task.getStore(storeName) != null &&
storeName.equals(task.getStore(storeName).name())) {
final T typedStore = validateAndCastStores(task.getStore(storeName), queryableStoreType, storeName, task.id());
return Collections.singletonList(typedStore);
}
}
return Collections.emptyList();
} else {
final List list = new ArrayList<>();
for (final Task task : tasks) {
final StateStore store = task.getStore(storeName);
if (store == null) {
// then this task doesn't have that store
} else {
final T typedStore = validateAndCastStores(store, queryableStoreType, storeName, task.id());
list.add(typedStore);
}
}
return list;
}
} else {
throw new InvalidStateStoreException("Cannot get state store " + storeName + " because the stream thread is " +
state + ", not RUNNING" +
(storeQueryParams.staleStoresEnabled() ? " or REBALANCING" : ""));
}
}
@SuppressWarnings("unchecked")
private static T validateAndCastStores(final StateStore store,
final QueryableStoreType queryableStoreType,
final String storeName,
final TaskId taskId) {
if (store == null) {
throw new NullPointerException("Expected store not to be null at this point.");
} else if (queryableStoreType.accepts(store)) {
if (!store.isOpen()) {
throw new InvalidStateStoreException(
"Cannot get state store " + storeName + " for task " + taskId +
" because the store is not open. " +
"The state store may have migrated to another instance.");
}
if (store instanceof TimestampedKeyValueStore && queryableStoreType instanceof QueryableStoreTypes.KeyValueStoreType) {
return (T) new ReadOnlyKeyValueStoreFacade<>((TimestampedKeyValueStore