errose28 commented on a change in pull request #1298: URL: https://github.com/apache/hadoop-ozone/pull/1298#discussion_r485192234
########## File path: hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/metadata/SchemaOneDeletedBlocksTable.java ########## @@ -0,0 +1,159 @@ +/* + * 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.hadoop.ozone.container.metadata; + +import org.apache.hadoop.hdds.utils.MetadataKeyFilters; +import org.apache.hadoop.hdds.utils.db.Table; +import org.apache.hadoop.hdds.utils.db.BatchOperation; +import org.apache.hadoop.hdds.utils.db.cache.CacheKey; +import org.apache.hadoop.hdds.utils.db.cache.CacheValue; +import org.apache.hadoop.ozone.container.common.helpers.ChunkInfoList; + +import java.io.IOException; +import java.util.List; + +/** + * For RocksDB instances written using DB schema version 1, all data is + * stored in the default column family. This differs from later schema + * versions, which put deleted blocks in a different column family. + * As a result, the block IDs used as keys for deleted blocks must be + * prefixed in schema version 1 so that they can be differentiated from + * regular blocks. However, these prefixes are not necessary in later schema + * versions, because the deleted blocks and regular blocks are in different + * column families. + * <p> + * Since clients must operate independently of the underlying schema version, + * This class is returned to clients using {@link DatanodeStoreSchemaOneImpl} + * instances, allowing them to access keys as if no prefix is + * required, while it adds the prefix when necessary. + * This means the client should omit the deleted prefix when putting and + * getting keys, regardless of the schema version. + * <p> + * Note that this class will only apply prefixes to keys as parameters, + * never as return types. This means that keys returned through iterators + * like {@link SchemaOneDeletedBlocksTable#getSequentialRangeKVs}, and + * {@link SchemaOneDeletedBlocksTable#getRangeKVs} will return keys prefixed + * with {@link SchemaOneDeletedBlocksTable#DELETED_KEY_PREFIX}. + */ Review comment: No such scenario that I am aware of, but I agree that this implementation is not ideal. I will change these methods to get the list from the parent class, and then make a pass through it to remove the prefixes before returning the list to the caller. This implementation would be similar to how TypedTable currently applies typing to iterator results returned from its raw table. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: ozone-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: ozone-issues-h...@hadoop.apache.org
