xiarixiaoyao commented on a change in pull request #4910: URL: https://github.com/apache/hudi/pull/4910#discussion_r828115674
########## File path: hudi-common/src/main/java/org/apache/hudi/common/util/TableInternalSchemaUtils.java ########## @@ -0,0 +1,140 @@ +/* + * 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.hudi.common.util; + +import com.github.benmanes.caffeine.cache.Cache; +import com.github.benmanes.caffeine.cache.Caffeine; + +import org.apache.hadoop.conf.Configuration; +import org.apache.hudi.common.model.HoodieCommitMetadata; +import org.apache.hudi.common.table.HoodieTableMetaClient; +import org.apache.hudi.common.table.timeline.HoodieInstant; +import org.apache.hudi.common.table.timeline.HoodieTimeline; +import org.apache.hudi.common.util.collection.Pair; +import org.apache.hudi.exception.HoodieException; +import org.apache.hudi.internal.schema.InternalSchema; +import org.apache.hudi.internal.schema.io.FileBasedInternalSchemaStorageManager; +import org.apache.hudi.internal.schema.utils.SerDeHelper; + +import java.util.List; +import java.util.TreeMap; +import java.util.stream.Collectors; + +public class TableInternalSchemaUtils { + // use segment lock to reduce competition. + // the lock size should be powers of 2 for better hash. + private static Object[] lockList = new Object[16]; + + static { + for (int i = 0; i < lockList.length; i++) { + lockList[i] = new Object(); + } + } + + // historySchemas cache maintain a map about (tablePath, HistorySchemas). + // this is a Global cache, all threads in one container/executor share the same cache. Review comment: 1) I don't want to get the schema from the historyschema every time in each spark task. So i want to use a static cache to cache the schemas which has been loaded. if we do alter command very frequently, this historySchema maybe large, it will be time cost when we search schema from historySchema. 2) every time we call TableInternalSchemaUtils.searchSchemaAndCache, the cache update action will be trigger. we call the function in both driver side and executor side. 3) yes, we should refresh cache when a new commit with updated schema gets adde, let me fixed this problem 4) of course we can simply read the history schema for every commit and pass it along, -- 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: commits-unsubscr...@hudi.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
