alex-plekhanov commented on a change in pull request #6916: IGNITE-12213: Sql objects system views. URL: https://github.com/apache/ignite/pull/6916#discussion_r330453659
########## File path: modules/core/src/main/java/org/apache/ignite/internal/managers/systemview/SystemViewCollectionContainerAdapter.java ########## @@ -0,0 +1,109 @@ +/* + * 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.ignite.internal.managers.systemview; + +import java.util.Collection; +import java.util.Iterator; +import java.util.function.BiFunction; +import java.util.function.Function; +import org.apache.ignite.spi.systemview.view.SystemView; +import org.apache.ignite.spi.systemview.view.SystemViewRowAttributeWalker; +import org.jetbrains.annotations.NotNull; + +import static java.util.Collections.emptyIterator; + +/** + * System view backed by {@code data} container. + * Each instance of {@code containers} collections should provide a collection of data. + * + * @see SystemView + */ +public class SystemViewCollectionContainerAdapter<C, R, D> extends AbstractSystemView<R> { + /** Collections of the data containers */ + private final Collection<C> containers; + + /** Function to extract collection of the data from container. */ + private final Function<C, Collection<D>> dataExtractor; + + /** Row function. */ + private final BiFunction<C, D, R> rowFunc; + + /** + * @param name Name. + * @param desc Description. + * @param rowCls Row class. + * @param walker Walker. + * @param containers Container of data. + * @param dataExtractor Data extractor function. + * @param rowFunc Row function. + */ + public SystemViewCollectionContainerAdapter(String name, String desc, Class<R> rowCls, + SystemViewRowAttributeWalker<R> walker, + Collection<C> containers, + Function<C, Collection<D>> dataExtractor, + BiFunction<C, D, R> rowFunc) { + super(name, desc, rowCls, walker); + + this.containers = containers; + this.dataExtractor = dataExtractor; + this.rowFunc = rowFunc; + } + + /** {@inheritDoc} */ + @Override public int size() { + int sz = 0; + + for (C c : containers) + sz += dataExtractor.apply(c).size(); + + return sz; + } + + /** {@inheritDoc} */ + @NotNull @Override public Iterator<R> iterator() { + return new Iterator<R>() { Review comment: I think it can be simplified by using `F.concat(F.iterator(...))` ---------------------------------------------------------------- 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 With regards, Apache Git Services
