gortiz commented on code in PR #10192: URL: https://github.com/apache/pinot/pull/10192#discussion_r1137258477
########## pinot-segment-spi/src/main/java/org/apache/pinot/segment/spi/index/IndexService.java: ########## @@ -0,0 +1,83 @@ +/** + * 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.pinot.segment.spi.index; + +import com.google.common.collect.Sets; +import java.util.HashSet; +import java.util.Optional; +import java.util.ServiceLoader; +import java.util.Set; + + +/** + * This is the entry point of the Index SPI. + * + * Ideally, if we used some kind of injection system, this class should be injected into a Pinot context all classes can + * receive when they are built. Given that Pinot doesn't have that, we have to relay on static fields. + * + * By default, this class will be initialized by reading all ServiceLoader SPI services that implement + * {@link IndexPlugin}, adding all the {@link IndexType} that can be found in that way. + * + * In case we want to change the instance to be used at runtime, the method {@link #setInstance(IndexService)} can be + * called. + */ +public class IndexService { + + private static volatile IndexService _instance = fromServiceLoader(); + + private final Set<IndexType<?, ?, ?>> _allIndexes; + + public IndexService(Set<IndexPlugin<?>> allPlugins) { + _allIndexes = Sets.newHashSetWithExpectedSize(allPlugins.size()); + + for (IndexPlugin<?> plugin : allPlugins) { + _allIndexes.add(plugin.getIndexType()); + } + } + + public static IndexService getInstance() { + return _instance; + } + + public static void setInstance(IndexService other) { + _instance = other; + } + + public static IndexService fromServiceLoader() { + Set<IndexPlugin<?>> pluginList = new HashSet<>(); + for (IndexPlugin indexPlugin : ServiceLoader.load(IndexPlugin.class)) { + pluginList.add(indexPlugin); + } + return new IndexService(pluginList); + } + + public Set<IndexType<?, ?, ?>> getAllIndexes() { + return _allIndexes; + } + + public Optional<IndexType<?, ?, ?>> getIndexTypeById(String indexId) { + return getAllIndexes().stream().filter(indexType -> indexType.getId().equalsIgnoreCase(indexId)).findAny(); Review Comment: No, it cannot be an enum. Enums are by definition a closed set of elements decided at compile time. The idea behind `index-spi` is to not define the indexes at compile time but at startup time. Therefore enums cannot be used. -- 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: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
