ibessonov commented on a change in pull request #208: URL: https://github.com/apache/ignite-3/pull/208#discussion_r670496677
########## File path: modules/configuration/src/main/java/org/apache/ignite/internal/configuration/util/OrderedMap.java ########## @@ -0,0 +1,198 @@ +/* + * 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.configuration.util; + +import java.util.ArrayList; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; + +/** + * Simplified map interfaces with better control over the keys order. + * + * @param <V> Type of the value. + */ +public class OrderedMap<V> { + /** Underlying hash map. */ + private final Map<String, V> map = new HashMap<>(); + + /** Ordered keys. */ + private final List<String> orderedKeys = new ArrayList<>(); + + /** Default constructor. */ + public OrderedMap() { + } + + /** + * Copy constructor. + * + * @param other Source of keys/values to copy from. + */ + public OrderedMap(OrderedMap<V> other) { + map.putAll(other.map); + orderedKeys.addAll(other.orderedKeys); + } + + /** + * Same as {@link Map#containsKey(Object)}. + * + * @param key Key to check. + * @return {@code true} if map contains the key. + */ + public boolean containsKey(String key) { + return map.containsKey(key); + } + + /** + * Same as {@link Map#get(Object)}. + * + * @param key Key to search. + * @return Value assiciated with the key or {@code null} is it's not found. + */ + public V get(String key) { + return map.get(key); + } + + /** + * Same as {@link Map#remove(Object)}. + * + * @param key Key to remove. + * @return Provious value assiciated with the key or {@code null} if map had no such key. + */ + public V remove(String key) { + if (map.containsKey(key)) + orderedKeys.remove(key); + + return map.remove(key); + } + + /** + * Put value to the map. Key will be the last if it didn't exist in map before. If key did exist then the same + * ordering index will be used. + * + * @param key Key to put. + * @param value Value associated with the key. + */ + public void put(String key, V value) { + if (!map.containsKey(key)) + orderedKeys.add(key); + + map.put(key, value); + } + + /** + * Put value to the map. + * + * @param idx Ordering index for the key. Treated as {@code 0} if negative. Treated as last index if out of bounds. + * @param key Key to put. + * @param value Value associated with the key. + * + * @throws IllegalArgumentException If key already exists in the map. + */ + public void putByIndex(int idx, String key, V value) { + if (map.containsKey(key)) + throw new IllegalArgumentException("Key " + key + " already exists."); + + if (idx >= orderedKeys.size()) + orderedKeys.add(key); + else + orderedKeys.add(idx, key); + + map.put(key, value); + } + + /** + * Put value to the map. + * + * @param base Previous key for the new key. Last key will be used if this one is missing from the map. + * @param key Key to put. + * @param value Value associated with the key. + * + * @throws IllegalArgumentException If key already exists in the map. + */ + public void putAfter(String base, String key, V value) { + if (map.containsKey(key)) + throw new IllegalArgumentException("Key " + key + " already exists."); + + int idx = orderedKeys.indexOf(base); + + putByIndex(idx < 0 ? orderedKeys.size() : idx + 1, key, value); + } + + /** + * Put value associated with key {@code oldKey} updaer a new key {@code newKey}. Do nothing if {@code oldKey} + * was missing from the map. + * + * @param oldKey Old key. + * @param newKey New key. + * + * @throws IllegalArgumentException If both {@code oldKey} and {@code newKey} already exist in the map. + */ + public void rename(String oldKey, String newKey) { + if (!map.containsKey(oldKey)) + return; + + if (map.containsKey(newKey)) + throw new IllegalArgumentException(); + + int idx = orderedKeys.indexOf(oldKey); + + orderedKeys.set(idx, newKey); + + V value = map.remove(oldKey); + + map.put(newKey, value); + } + + /** + * @return List of keys. + */ + public List<String> keys() { + return new ArrayList<>(orderedKeys); Review comment: This list will be used to iterate keys and remove some of them from the map. There would be ConcurrentModificationException otherwise. -- 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. 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