org.apache.kafka.streams.state.internals.QueryableStoreProvider Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.streams.state.internals;
import org.apache.kafka.streams.StoreQueryParameters;
import org.apache.kafka.streams.processor.StateStore;
import org.apache.kafka.streams.state.QueryableStoreType;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* A wrapper over all of the {@link StateStoreProvider}s in a Topology
*
* The store providers field is a reference
*/
public class QueryableStoreProvider {
// map of StreamThread.name to StreamThreadStateStoreProvider
private final Map storeProviders;
private final GlobalStateStoreProvider globalStoreProvider;
public QueryableStoreProvider(final GlobalStateStoreProvider globalStateStoreProvider) {
this.storeProviders = new HashMap<>();
this.globalStoreProvider = globalStateStoreProvider;
}
/**
* Get a composite object wrapping the instances of the {@link StateStore} with the provided
* storeName and {@link QueryableStoreType}
*
* @param storeQueryParameters if stateStoresEnabled is used i.e. staleStoresEnabled is true, include standbys and recovering stores;
* if stateStoresDisabled i.e. staleStoresEnabled is false, only include running actives;
* if partition is null then it fetches all local partitions on the instance;
* if partition is set then it fetches a specific partition.
* @param The expected type of the returned store
* @return A composite object that wraps the store instances.
*/
public T getStore(final StoreQueryParameters storeQueryParameters) {
final String storeName = storeQueryParameters.storeName();
final QueryableStoreType queryableStoreType = storeQueryParameters.queryableStoreType();
final List globalStore = globalStoreProvider.stores(storeName, queryableStoreType);
if (!globalStore.isEmpty()) {
return queryableStoreType.create(globalStoreProvider, storeName);
}
return queryableStoreType.create(
new WrappingStoreProvider(storeProviders.values(), storeQueryParameters),
storeName
);
}
public void addStoreProviderForThread(final String threadName, final StreamThreadStateStoreProvider streamThreadStateStoreProvider) {
this.storeProviders.put(threadName, streamThreadStateStoreProvider);
}
public void removeStoreProviderForThread(final String threadName) {
this.storeProviders.remove(threadName);
}
}