gortiz commented on code in PR #10191: URL: https://github.com/apache/pinot/pull/10191#discussion_r1093069106
########## pinot-segment-spi/src/main/java/org/apache/pinot/segment/spi/index/IndexType.java: ########## @@ -0,0 +1,171 @@ +/** + * 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.fasterxml.jackson.databind.JsonNode; +import java.io.IOException; +import java.util.Map; +import javax.annotation.Nullable; +import org.apache.pinot.segment.spi.ColumnMetadata; +import org.apache.pinot.segment.spi.creator.IndexCreationContext; +import org.apache.pinot.segment.spi.index.column.ColumnIndexContainer; +import org.apache.pinot.segment.spi.store.SegmentDirectory; +import org.apache.pinot.spi.config.table.FieldConfig; +import org.apache.pinot.spi.config.table.TableConfig; +import org.apache.pinot.spi.data.Schema; +import org.apache.pinot.spi.utils.JsonUtils; + + +/** + * TODO: implement mutable indexes. + * @param <C> the class that represents how this object is configured. + * @param <IR> the {@link IndexReader} subclass that should be used to read indexes of this type. + * @param <IC> the {@link IndexCreator} subclass that should be used to create indexes of this type. + */ +public interface IndexType<C, IR extends IndexReader, IC extends IndexCreator> { + + /** + * The unique id that identifies this index type. + * In case there is more than one implementation for a given index, then all should share the same id in order to be + * correctly registered in the {@link IndexService}. + * This is also the value being used as the default toString implementation and the one used as keys when config is + * specified. + * + * <p>Therefore the returned value for each index should be constant across different Pinot versions.</p> + */ + String getId(); Review Comment: It is explained in the javadoc, right? The `id` is the term that is being used to talk with customers. Is what they specify in the configuration and what is shown to them if there is an error. The `indexName` is a literal we use internally. Usually the definitions should be the opposite, but I followed this convention to preserve the concepts that exist in `ColumnIndexType`. In other words: `IndexType.id` is equal to `ColumnIndexType` values (aka their literal) in lowercase while `IndexType.getIndexName` is `ColumnIndexType._indexName`. I would like to remove `IndexType.getIndexName`, but we need to keep something like that in order to be able to read segment where the index buffer was stored with `IndexKey` that use things like `forward_index` as value or in places like the metadata_info. You can see the implementation in https://github.com/gortiz/pinot/pull/2/files. For example [here](https://github.com/gortiz/pinot/blob/6134e032771afcac8458f9def3c2d9a4d76e6a5f/pinot-segment-local/src/main/java/org/apache/pinot/segment/local/segment/index/forward/ForwardIndexType.java): ```java public class ForwardIndexType implements IndexType<Object, IndexReader, IndexCreator> { public static final ForwardIndexType INSTANCE = new ForwardIndexType(); private ForwardIndexType() { } @Override public String getId() { return "forward"; } @Override public String getIndexName() { return "forward_index"; } @Override public String toString() { return getId(); } } ``` -- 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
