mosche commented on code in PR #24009: URL: https://github.com/apache/beam/pull/24009#discussion_r1025008501
########## runners/spark/3/src/main/java/org/apache/beam/runners/spark/structuredstreaming/translation/helpers/EncoderProvider.java: ########## @@ -0,0 +1,58 @@ +/* + * 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.runners.spark.structuredstreaming.translation.helpers; + +import static org.apache.beam.runners.spark.structuredstreaming.translation.helpers.EncoderHelpers.kvEncoder; + +import java.util.function.Function; +import org.apache.beam.sdk.annotations.Internal; +import org.apache.beam.sdk.coders.Coder; +import org.apache.beam.sdk.coders.KvCoder; +import org.apache.beam.sdk.values.KV; +import org.apache.spark.sql.Encoder; + +@Internal +public interface EncoderProvider { + interface Factory<T> extends Function<Coder<T>, Encoder<T>> { + Factory<?> INSTANCE = EncoderHelpers::encoderFor; + } + + <T> Encoder<T> encoderOf(Coder<T> coder, Factory<T> factory); + + default <T> Encoder<T> encoderOf(Coder<T> coder) { + return coder instanceof KvCoder + ? (Encoder<T>) kvEncoderOf((KvCoder) coder) + : encoderOf(coder, encoderFactory()); + } + + default <K, V> Encoder<KV<K, V>> kvEncoderOf(KvCoder<K, V> coder) { + return encoderOf(coder, c -> kvEncoder(keyEncoderOf(coder), valueEncoderOf(coder))); + } + + default <K, V> Encoder<K> keyEncoderOf(KvCoder<K, V> coder) { + return encoderOf(coder.getKeyCoder(), encoderFactory()); + } + + default <K, V> Encoder<V> valueEncoderOf(KvCoder<K, V> coder) { + return encoderOf(coder.getValueCoder(), encoderFactory()); + } + + default <T> Factory<T> encoderFactory() { + return (Factory<T>) Factory.INSTANCE; Review Comment: This avoids having to repeatedly create instances of the default factory. `INSTANCE` certainly belongs into `Factory`, that's a very common pattern. I'll keep this as is. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
