amogh-jahagirdar commented on code in PR #6559: URL: https://github.com/apache/iceberg/pull/6559#discussion_r1181315995
########## core/src/main/java/org/apache/iceberg/view/ViewMetadata.java: ########## @@ -0,0 +1,126 @@ +/* + * 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.view; + +import java.io.Serializable; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import javax.annotation.Nullable; +import org.apache.iceberg.Schema; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableMap; +import org.apache.iceberg.relocated.com.google.common.collect.Ordering; +import org.immutables.value.Value; + [email protected] +public abstract class ViewMetadata implements Serializable { + static final int DEFAULT_VIEW_FORMAT_VERSION = 1; + static final int SUPPORTED_VIEW_FORMAT_VERSION = 1; + + public static ImmutableViewMetadata.Builder buildFrom(ViewMetadata metadata) { + return ImmutableViewMetadata.builder() + .formatVersion(DEFAULT_VIEW_FORMAT_VERSION) + .location(metadata.location()) + .properties(metadata.properties()) + .currentVersionId(metadata.currentVersionId()) + .versions(metadata.versions()) + .schemas(metadata.schemas()) + .currentSchemaId(metadata.currentSchemaId()) + .history(metadata.history()); + } + + @Value.Check + void check() { + Preconditions.checkState(versions().size() > 0, "Expecting non-empty version log"); + checkVersionLog(history()); + } + + public abstract int formatVersion(); + + public abstract String location(); + + public abstract Map<String, String> properties(); + + public abstract int currentVersionId(); + + public abstract List<ViewVersion> versions(); + + public abstract List<ViewHistoryEntry> history(); + + @Nullable + public abstract List<Schema> schemas(); + + @Nullable + public abstract Integer currentSchemaId(); + + public ViewVersion version(int versionId) { + return versionsById().get(versionId); + } + + @Value.Derived + public ViewVersion currentVersion() { + return versionsById().get(currentVersionId()); + } + + @Value.Derived + public Map<Integer, ViewVersion> versionsById() { + return indexVersions(versions()); + } + + @Value.Derived + public Map<Integer, Schema> schemasById() { + return indexSchemas(schemas()); + } + + @Value.Derived + public Schema schema() { + return schemasById().get(currentSchemaId()); + } + + private static void checkVersionLog(List<ViewHistoryEntry> versionLog) { + Preconditions.checkState(versionLog.size() > 0, "Expecting non-empty version log"); Review Comment: If the log is missing this implies bad or corrupted view metadata. At minimum there must be at least 1 view version for the view to be considered as well defined. The original rationale was that if the metadata file corrupted, one shouldn't be able to read the view because there may be a correctness issue. Alternatively, we could remove the validation since at the end of the day as long as current-version is well defined then the read can progress. With this approach I'm just concerned that if version-log is missing, and reads succeed then "corruption" just propagates silently as the view evolves and in the case of a genuine issue it can confuse someone trying to diagnose the issue. It seems better just to have a guarantee that version-log is well defined a the time of reading the view. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
