nastra commented on code in PR #11769: URL: https://github.com/apache/iceberg/pull/11769#discussion_r1883806469
########## core/src/main/java/org/apache/iceberg/rest/HTTPHeaders.java: ########## @@ -0,0 +1,168 @@ +/* + * 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.rest; + +import java.util.List; +import java.util.Locale; +import java.util.Map; +import java.util.stream.Collectors; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableListMultimap; +import org.apache.iceberg.relocated.com.google.common.collect.ListMultimap; +import org.apache.iceberg.relocated.com.google.common.collect.Multimap; +import org.immutables.value.Value; + +/** + * Represents a group of HTTP headers. + * + * <p>Header name comparison in this class is always case-insensitive, in accordance with RFC 2616. + * + * <p>This class exposes methods to convert to and from different representations such as maps and + * multimap, for easier access and manipulation – especially when dealing with multiple headers with + * the same name. + */ +@Value.Style(depluralize = true) +@Value.Immutable +@SuppressWarnings({"ImmutablesStyle", "SafeLoggingPropagation"}) +public interface HTTPHeaders { + + HTTPHeaders EMPTY = of(); + + /** Returns all the header entries in this group. */ + List<HTTPHeader> entries(); + + /** + * Returns a map representation of the headers where each header name is mapped to a list of its + * values. Header names are case-insensitive. + */ + @Value.Lazy + default Map<String, List<String>> asMap() { + return entries().stream() + .collect(Collectors.groupingBy(h -> h.name().toLowerCase(Locale.ROOT))) + .values() + .stream() + .collect( + Collectors.toMap( + headers -> headers.get(0).name(), + headers -> headers.stream().map(HTTPHeader::value).collect(Collectors.toList()))); + } + + /** + * Returns a simple map representation of the headers where each header name is mapped to its + * first value. If a header has multiple values, only the first value is used. Header names are + * case-insensitive. + */ + @Value.Lazy + default Map<String, String> asSimpleMap() { + return entries().stream() + .collect(Collectors.groupingBy(h -> h.name().toLowerCase(Locale.ROOT))) + .values() + .stream() + .collect( + Collectors.toMap(headers -> headers.get(0).name(), headers -> headers.get(0).value())); + } + + /** + * Returns a {@link ListMultimap} representation of the headers. Header names are + * case-insensitive. + */ + @Value.Lazy + default ListMultimap<String, String> asMultiMap() { + return entries().stream() + .collect(Collectors.groupingBy(h -> h.name().toLowerCase(Locale.ROOT))) + .values() + .stream() + .collect( + ImmutableListMultimap.flatteningToImmutableListMultimap( + headers -> headers.get(0).name(), + headers -> headers.stream().map(HTTPHeader::value))); + } + + /** Returns all the entries in this group for the given name (case-insensitive). */ + default List<HTTPHeader> entries(String name) { + return entries().stream() + .filter(header -> header.name().equalsIgnoreCase(name)) + .collect(Collectors.toList()); + } + + /** Returns whether this group contains an entry with the given name (case-insensitive). */ + default boolean contains(String name) { + return entries().stream().anyMatch(header -> header.name().equalsIgnoreCase(name)); + } + + /** + * Adds the given header to the current group if no entry with the same name is already present. + * Returns a new instance with the added header, or the current instance if the header is already + * present. + */ + default HTTPHeaders addIfAbsent(HTTPHeader header) { + return contains(header.name()) + ? this + : ImmutableHTTPHeaders.builder().from(this).addEntry(header).build(); + } + + /** + * Adds the given headers to the current group if no entries with same names are already present. + * Returns a new instance with the added headers, or the current instance if all headers are + * already present. + */ + default HTTPHeaders addIfAbsent(HTTPHeaders headers) { + List<HTTPHeader> newHeaders = + headers.entries().stream().filter(e -> !contains(e.name())).collect(Collectors.toList()); + return newHeaders.isEmpty() + ? this + : ImmutableHTTPHeaders.builder().from(this).addAllEntries(newHeaders).build(); + } + + static HTTPHeaders of(HTTPHeader... headers) { + return ImmutableHTTPHeaders.builder().addEntries(headers).build(); + } + + static HTTPHeaders fromMap(Map<String, ? extends Iterable<String>> headers) { + ImmutableHTTPHeaders.Builder builder = ImmutableHTTPHeaders.builder(); + headers.forEach( + (name, values) -> values.forEach(value -> builder.addEntry(HTTPHeader.of(name, value)))); + return builder.build(); + } + + static HTTPHeaders fromSimpleMap(Map<String, String> headers) { + ImmutableHTTPHeaders.Builder builder = ImmutableHTTPHeaders.builder(); + headers.forEach((name, value) -> builder.addEntry(HTTPHeader.of(name, value))); + return builder.build(); + } + + static HTTPHeaders fromMultiMap(Multimap<String, String> headers) { Review Comment: The Iceberg project typically tries to only add things to APIs that are needed for current use cases instead of planning for potential use cases that may or may not actually exist/happen (independent of whether there are tests for unused methods or not). You also have to keep in mind that everything that's being added to `iceberg-core` can't be easily changed without going through an API deprecation cycle, so we're trying to be mindful about what's really required in terms of APIs -- 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
