RussellSpitzer commented on code in PR #9047: URL: https://github.com/apache/iceberg/pull/9047#discussion_r1396328736
########## api/src/main/java/org/apache/iceberg/util/CharSequenceMap.java: ########## @@ -0,0 +1,230 @@ +/* + * 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.iceberg.util; + +import java.io.Serializable; +import java.util.Collection; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.relocated.com.google.common.collect.Sets; + +/** + * A map that uses char sequences as keys. + * + * <p>This implementation wraps provided keys into {@link CharSequenceWrapper} for consistent + * hashing and equals behavior. This ensures that objects of different types that represent the same + * sequence of characters are treated as equal keys in the map. + * + * <p>Note: This map is not designed for concurrent modification by multiple threads. However, it + * supports safe concurrent reads, assuming there are no concurrent writes. + * + * <p>Note: This map does not support null keys. + * + * @param <V> the type of values + */ +public class CharSequenceMap<V> implements Map<CharSequence, V>, Serializable { + + private static final long serialVersionUID = 1L; + private static final ThreadLocal<CharSequenceWrapper> WRAPPERS = + ThreadLocal.withInitial(() -> CharSequenceWrapper.wrap(null)); + + private final Map<CharSequenceWrapper, V> wrapperMap; + + private CharSequenceMap() { + this.wrapperMap = Maps.newHashMap(); + } + + public static <T> CharSequenceMap<T> create() { + return new CharSequenceMap<>(); + } + + @Override + public int size() { + return wrapperMap.size(); + } + + @Override + public boolean isEmpty() { + return wrapperMap.isEmpty(); + } + + @Override + public boolean containsKey(Object key) { + if (key instanceof CharSequence) { + CharSequenceWrapper wrapper = WRAPPERS.get(); + boolean result = wrapperMap.containsKey(wrapper.set((CharSequence) key)); + wrapper.set(null); // don't hold a reference to the key + return result; + } + + return false; + } + + @Override + public boolean containsValue(Object value) { + return wrapperMap.containsValue(value); + } + + @Override + public V get(Object key) { + if (key instanceof CharSequence) { + CharSequenceWrapper wrapper = WRAPPERS.get(); + V result = wrapperMap.get(wrapper.set((CharSequence) key)); + wrapper.set(null); // don't hold a reference to the value + return result; + } + + return null; + } + + @Override + public V put(CharSequence key, V value) { + return wrapperMap.put(CharSequenceWrapper.wrap(key), value); + } + + @Override + public V remove(Object key) { + if (key instanceof CharSequence) { + CharSequenceWrapper wrapper = WRAPPERS.get(); + V result = wrapperMap.remove(wrapper.set((CharSequence) key)); + wrapper.set(null); // don't hold a reference to the value + return result; + } + + return null; + } + + @Override + public void putAll(Map<? extends CharSequence, ? extends V> otherMap) { + otherMap.forEach(this::put); + } + + @Override + public void clear() { + wrapperMap.clear(); + } + + @Override + public Set<CharSequence> keySet() { + CharSequenceSet keySet = CharSequenceSet.empty(); + + for (CharSequenceWrapper wrapper : wrapperMap.keySet()) { + keySet.add(wrapper.get()); + } + + return keySet; + } + + @Override + public Collection<V> values() { + return wrapperMap.values(); + } + + @Override + public Set<Entry<CharSequence, V>> entrySet() { + Set<Entry<CharSequence, V>> entrySet = Sets.newHashSet(); + + for (Entry<CharSequenceWrapper, V> entry : wrapperMap.entrySet()) { + entrySet.add(new CharSequenceEntry<>(entry)); + } + + return entrySet; + } + + @Override + public boolean equals(Object other) { + if (this == other) { + return true; + } else if (other == null || getClass() != other.getClass()) { + return false; + } + + CharSequenceMap<?> that = (CharSequenceMap<?>) other; + return Objects.equals(wrapperMap, that.wrapperMap); + } + + @Override + public int hashCode() { + return Objects.hashCode(wrapperMap); + } + + @Override + public String toString() { + StringBuilder builder = new StringBuilder(); + + builder.append('{'); + + for (Entry<CharSequence, V> entry : entrySet()) { Review Comment: personal pref but I like doing .map().joining(...) -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
