mjsax commented on code in PR #13264: URL: https://github.com/apache/kafka/pull/13264#discussion_r1117766784
########## streams/src/main/java/org/apache/kafka/streams/state/internals/KeyValueStoreWrapper.java: ########## @@ -0,0 +1,204 @@ +/* + * 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.kafka.streams.state.internals; + +import org.apache.kafka.streams.errors.InvalidStateStoreException; +import org.apache.kafka.streams.processor.StateStore; +import org.apache.kafka.streams.processor.StateStoreContext; +import org.apache.kafka.streams.processor.api.ProcessorContext; +import org.apache.kafka.streams.query.Position; +import org.apache.kafka.streams.query.PositionBound; +import org.apache.kafka.streams.query.Query; +import org.apache.kafka.streams.query.QueryConfig; +import org.apache.kafka.streams.query.QueryResult; +import org.apache.kafka.streams.state.TimestampedKeyValueStore; +import org.apache.kafka.streams.state.ValueAndTimestamp; +import org.apache.kafka.streams.state.VersionedKeyValueStore; +import org.apache.kafka.streams.state.VersionedRecord; + +/** + * A wrapper class for non-windowed key-value stores used within the DSL. All such stores are + * instances of either {@link TimestampedKeyValueStore} or {@link VersionedKeyValueStore}. + * + * @param <K> The key type + * @param <V> The value type + */ +public class KeyValueStoreWrapper<K, V> implements StateStore { + + private TimestampedKeyValueStore<K, V> timestampedStore = null; + private VersionedKeyValueStore<K, V> versionedStore = null; + + public KeyValueStoreWrapper(final ProcessorContext<?, ?> context, final String storeName) { + try { + // first try timestamped store + timestampedStore = context.getStateStore(storeName); + return; + } catch (final ClassCastException e) { + // ignore since could be versioned store instead + } + + try { + // next try versioned store + versionedStore = context.getStateStore(storeName); + } catch (final ClassCastException e) { + throw new InvalidStateStoreException("KTable source state store must implement either TimestampedKeyValueStore or VersionedKeyValueStore."); + } + } + + public ValueAndTimestamp<V> get(final K key) { + if (timestampedStore != null) { + return timestampedStore.get(key); + } + if (versionedStore != null) { + final VersionedRecord<V> versionedRecord = versionedStore.get(key); + return versionedRecord == null + ? null + : ValueAndTimestamp.make(versionedRecord.value(), versionedRecord.timestamp()); + } + throw new IllegalStateException("KeyValueStoreWrapper must be initialized with either timestamped or versioned store"); + } + + public void put(final K key, final V value, final long timestamp) { + if (timestampedStore != null) { + timestampedStore.put(key, ValueAndTimestamp.make(value, timestamp)); + return; + } + if (versionedStore != null) { + versionedStore.put(key, value, timestamp); + return; + } + throw new IllegalStateException("KeyValueStoreWrapper must be initialized with either timestamped or versioned store"); + } + + public StateStore getStore() { Review Comment: Do we really need this method? It seem whoever uses `KeyValueStoreWrapper` can keep a handle of the store themselves? If we think it's convenient to keep this helper, should we add a `Store store` member variable, and implement this one a simple `return store`? (Similar for `name()`, `init()` etc below?) If we don't get the correct stores passed into the constructor we fail anyway, and it seem a lot of unncessary boiler plate code in those "non-functional helpers" -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
