rdblue commented on a change in pull request #3883: URL: https://github.com/apache/iceberg/pull/3883#discussion_r795274832
########## File path: core/src/main/java/org/apache/iceberg/BaseUpdateSnapshotRefs.java ########## @@ -0,0 +1,128 @@ +/* + * 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; + +import java.util.Map; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; + +public class BaseUpdateSnapshotRefs implements UpdateSnapshotRefs { + + private final TableOperations ops; + private final TableMetadata base; + private final Map<String, SnapshotRef> refs; + + BaseUpdateSnapshotRefs(TableOperations ops) { + this.ops = ops; + this.base = ops.current(); + this.refs = Maps.newHashMap(base.refs()); + } + + @Override + public UpdateSnapshotRefs tag(String name, long snapshotId) { + Preconditions.checkArgument(name != null, "Tag name must not be null"); + Preconditions.checkArgument(base.snapshot(snapshotId) != null, "Cannot find snapshot with ID: %s", snapshotId); + Preconditions.checkArgument(!refs.containsKey(name), "Cannot tag snapshot, ref already exists: %s", name); + + refs.put(name, SnapshotRef.tagBuilder(snapshotId).build()); + return this; + } + + @Override + public UpdateSnapshotRefs branch(String name, long snapshotId) { + Preconditions.checkArgument(name != null, "Branch name must not be null"); + Preconditions.checkArgument(base.snapshot(snapshotId) != null, "Cannot find snapshot with ID: %s", snapshotId); + Preconditions.checkArgument(!refs.containsKey(name), "Cannot create branch, ref already exists: %s", name); Review comment: Yes, I think you're right. There are use cases for both branching and tagging in the snapshot producer updates. Here's what I'm thinking for the API: * `SnapshotProducer.stageOnly()` - like the current behavior, creates a snapshot without updating a branch * `SnapshotProducer.forBranch(String name)` - commit changes to the given branch * Defaults to "main" branch if not called * Incompatible with `stageOnly()` * If the branch does not exist, it will be created from main * `SnapshotProducer.withTag(String name)` - tag the committed snapshot as name * May be used with `stageOnly()` or `forBranch(...)` This behavior differs from what you were talking about because this will create the branch if it doesn't exist, which means that you wouldn't throw an exception if someone dropped a branch that a job was writing to. I think that's okay because writes are expensive. The best thing to do is to accept the new snapshot and correctly label it -- the user can always drop it easily if it is actually unwanted. Another reason to do this is to make it easy to create branches. You just write to a branch and it forks from master. Here are a few examples of these: ```java // WAP commit with identification tag table.newAppend() .appendFile(fileA) .stageOnly() .withTag(wapId) .commit(); // create or update "sql_refactor" branch table.newReplacePartitions() .addFile(fileA) .forBranch("sql_refactor") .commit(); // tag the main branch and commit table.newRewrite() .rewriteFiles(originals, replacements) .withTag("compact_15_of_16") .commit(); ``` -- 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]
