jerryshao commented on code in PR #7181: URL: https://github.com/apache/gravitino/pull/7181#discussion_r2094747153
########## core/src/main/java/org/apache/gravitino/cache/MetaCache.java: ########## @@ -0,0 +1,128 @@ +/* + * 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.gravitino.cache; + +import java.io.IOException; +import java.util.Optional; +import org.apache.gravitino.Entity; +import org.apache.gravitino.HasIdentifier; +import org.apache.gravitino.NameIdentifier; + +/** + * {@code MetaCache} is a cache interface in Gravitino designed to accelerate metadata access for + * entities. It maintains a bidirectional mapping between an {@link Entity} and its {@code id}, as + * well as its {@link NameIdentifier}. The cache also supports cascading removal of entries, + * ensuring related sub-entities are cleared together. + */ +public interface MetaCache { + /** + * Retrieves an entity by its name identifier and type. If the entity is not present in the cache, + * it will be loaded from the backing EntityStore. + * + * @param ident The name identifier of the entity + * @param type The type of the entity + * @return The cached or newly loaded Entity instance + * @param <E> The class of the entity + * @throws IOException if the operation fails + */ + <E extends Entity & HasIdentifier> E getOrLoad(NameIdentifier ident, Entity.EntityType type) + throws IOException; + + /** + * Retrieves an entity from the cache if it exists. Will not attempt to load from the store if + * missing. + * + * @param ident the name identifier + * @param type the entity type + * @param <E> the entity class + * @return an optional entity if cached + */ + <E extends Entity & HasIdentifier> Optional<E> getIfPresent( + NameIdentifier ident, Entity.EntityType type); + + /** + * Invalidates the cache entry for the given entity. Does not affect the underlying storage. + * + * @param ident the name identifier + * @param type the entity type + * @return true if the cache entry was removed + */ + default boolean invalidate(NameIdentifier ident, Entity.EntityType type) { + return remove(ident, type, false); + } + + /** + * Removes the entity from both cache and optionally the underlying store. + * + * @param ident the name identifier + * @param type the entity type + * @param removeFromStore true to also delete from store + * @return true if removed from cache + */ + boolean remove(NameIdentifier ident, Entity.EntityType type, boolean removeFromStore); + + /** + * Shortcut to remove from both cache and store. + * + * @param ident the name identifier + * @param type the entity type + * @return true if removed + */ + default boolean remove(NameIdentifier ident, Entity.EntityType type) { + return remove(ident, type, true); + } + + /** + * Checks whether an entity with the given name identifier and type is present in the cache. + * + * @param ident the name identifier of the entity + * @param type the type of the entity + * @return {@code true} if the entity is cached; {@code false} otherwise + */ + boolean contains(NameIdentifier ident, Entity.EntityType type); + + /** + * Returns the current number of entries stored in the data cache. Review Comment: The number of entries, or the size of memory? -- 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...@gravitino.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
