dimas-b commented on code in PR #1528: URL: https://github.com/apache/polaris/pull/1528#discussion_r2080097116
########## polaris-core/src/main/java/org/apache/polaris/core/persistence/pagination/PageToken.java: ########## @@ -0,0 +1,99 @@ +/* + * 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.polaris.core.persistence.pagination; + +import java.util.List; + +/** + * Represents a page token that can be used by operations like `listTables`. Clients that specify a + * `pageSize` (or a `pageToken`) may receive a `next-page-token` in the response, the content of + * which is a serialized PageToken. + * + * <p>By providing that in the next query's `pageToken`, the client can resume listing where they + * left off. If the client provides a `pageToken` or `pageSize` but `next-page-token` is null in the + * response, that means there is no more data to read. + */ +public abstract class PageToken { + + /** Build a new PageToken that reads everything */ + public static PageToken readEverything() { + return build(null, null); + } + + /** Build a new PageToken from an input String, without a specified page size */ + public static PageToken fromString(String token) { + return build(token, null); + } + + /** Build a new PageToken from a limit */ + public static PageToken fromLimit(Integer pageSize) { + return build(null, pageSize); + } + + /** Build a {@link PageToken} from the input string and page size */ + public static PageToken build(String token, Integer pageSize) { + if (token == null || token.isEmpty()) { + if (pageSize != null) { + return new ReadFromStartPageToken(pageSize); + } else { + return new ReadEverythingPageToken(); + } + } else { + // TODO implement, split out by the token's prefix + return new ReadEverythingPageToken(); Review Comment: re: backward compatibility, clients are not supposed to "invent" page tokens, but Polaris in this PR still should never return a valid non-empty token. -- 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...@polaris.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
