JonasJ-ap commented on code in PR #6449: URL: https://github.com/apache/iceberg/pull/6449#discussion_r1087287064
########## delta-lake/src/main/java/org/apache/iceberg/delta/BaseSnapshotDeltaLakeTableAction.java: ########## @@ -0,0 +1,403 @@ +/* + * 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.delta; + +import io.delta.standalone.DeltaLog; +import io.delta.standalone.VersionLog; +import io.delta.standalone.actions.Action; +import io.delta.standalone.actions.AddFile; +import io.delta.standalone.actions.RemoveFile; +import java.io.File; +import java.net.URI; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; +import org.apache.commons.codec.DecoderException; +import org.apache.commons.codec.net.URLCodec; +import org.apache.hadoop.conf.Configuration; +import org.apache.iceberg.AppendFiles; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFiles; +import org.apache.iceberg.FileFormat; +import org.apache.iceberg.Metrics; +import org.apache.iceberg.MetricsConfig; +import org.apache.iceberg.OverwriteFiles; +import org.apache.iceberg.PartitionField; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.Schema; +import org.apache.iceberg.Snapshot; +import org.apache.iceberg.SnapshotSummary; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableProperties; +import org.apache.iceberg.Transaction; +import org.apache.iceberg.avro.Avro; +import org.apache.iceberg.catalog.Catalog; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.exceptions.ValidationException; +import org.apache.iceberg.hadoop.HadoopFileIO; +import org.apache.iceberg.io.InputFile; +import org.apache.iceberg.mapping.MappingUtil; +import org.apache.iceberg.mapping.NameMapping; +import org.apache.iceberg.mapping.NameMappingParser; +import org.apache.iceberg.orc.OrcMetrics; +import org.apache.iceberg.parquet.ParquetUtil; +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.Lists; +import org.apache.iceberg.types.Type; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Takes a Delta Lake table's location and attempts to create an Iceberg table snapshot in an + * optional user-specified location (default to the Delta Lake table's location) with a different + * identifier. + */ +class BaseSnapshotDeltaLakeTableAction implements SnapshotDeltaLakeTable { + + private static final Logger LOG = LoggerFactory.getLogger(BaseSnapshotDeltaLakeTableAction.class); + + private static final String SNAPSHOT_SOURCE_PROP = "snapshot_source"; + private static final String DELTA_SOURCE_VALUE = "delta"; + private static final String ORIGINAL_LOCATION_PROP = "original_location"; + private static final String PARQUET_SUFFIX = ".parquet"; + private static final String AVRO_SUFFIX = ".avro"; + private static final String ORC_SUFFIX = ".orc"; + private final ImmutableMap.Builder<String, String> additionalPropertiesBuilder = + ImmutableMap.builder(); + private DeltaLog deltaLog; + private Catalog icebergCatalog; + private final String deltaTableLocation; + private TableIdentifier newTableIdentifier; + private String newTableLocation; + private HadoopFileIO deltaLakeFileIO; + private long deltaStartVersion; + + /** + * Snapshot a delta lake table to be an iceberg table. The action will read the delta lake table's + * log through the table's path, create a new iceberg table using the given icebergCatalog and + * newTableIdentifier, and commit all changes in one iceberg transaction. + * + * <p>The new table will only be created if the snapshot is successful. + * + * @param deltaTableLocation the delta lake table's path + */ + BaseSnapshotDeltaLakeTableAction(String deltaTableLocation) { + this.deltaTableLocation = deltaTableLocation; + this.newTableLocation = deltaTableLocation; + } + + @Override + public SnapshotDeltaLakeTable tableProperties(Map<String, String> properties) { + additionalPropertiesBuilder.putAll(properties); + return this; + } + + @Override + public SnapshotDeltaLakeTable tableProperty(String name, String value) { + additionalPropertiesBuilder.put(name, value); + return this; + } + + @Override + public SnapshotDeltaLakeTable tableLocation(String location) { + this.newTableLocation = location; + return this; + } + + @Override + public SnapshotDeltaLakeTable as(TableIdentifier identifier) { + this.newTableIdentifier = identifier; + return this; + } + + @Override + public SnapshotDeltaLakeTable icebergCatalog(Catalog catalog) { + this.icebergCatalog = catalog; + return this; + } + + @Override + public SnapshotDeltaLakeTable deltaLakeConfiguration(Configuration conf) { + this.deltaLog = DeltaLog.forTable(conf, deltaTableLocation); + this.deltaLakeFileIO = new HadoopFileIO(conf); + // get the earliest version available in the delta lake table + this.deltaStartVersion = deltaLog.getVersionAtOrAfterTimestamp(0L); + return this; + } + + @Override + public Result execute() { + Preconditions.checkArgument( + icebergCatalog != null && newTableIdentifier != null, + "Iceberg catalog and identifier cannot be null. Make sure to configure the action with a valid Iceberg catalog and identifier."); + Preconditions.checkArgument( + deltaLog != null && deltaLakeFileIO != null, + "Make sure to configure the action with a valid deltaLakeConfiguration"); + Preconditions.checkArgument( + deltaLog.tableExists(), + "Delta lake table does not exist at the given location: %s", + deltaTableLocation); + io.delta.standalone.Snapshot updatedSnapshot = deltaLog.update(); + Schema schema = convertDeltaLakeSchema(updatedSnapshot.getMetadata().getSchema()); + PartitionSpec partitionSpec = getPartitionSpecFromDeltaSnapshot(schema); + Transaction icebergTransaction = + icebergCatalog.newCreateTableTransaction( + newTableIdentifier, + schema, + partitionSpec, + newTableLocation, + destTableProperties(updatedSnapshot, deltaTableLocation)); + icebergTransaction + .table() + .updateProperties() + .set( + TableProperties.DEFAULT_NAME_MAPPING, + NameMappingParser.toJson(MappingUtil.create(icebergTransaction.table().schema()))) + .commit(); + Iterator<VersionLog> versionLogIterator = + deltaLog.getChanges( + deltaStartVersion, false // not throw exception when data loss detected + ); + while (versionLogIterator.hasNext()) { + VersionLog versionLog = versionLogIterator.next(); + commitDeltaVersionLogToIcebergTransaction(versionLog, icebergTransaction); + } + Snapshot icebergSnapshot = icebergTransaction.table().currentSnapshot(); + long totalDataFiles = + icebergSnapshot != null + ? Long.parseLong(icebergSnapshot.summary().get(SnapshotSummary.TOTAL_DATA_FILES_PROP)) + : 0; + + icebergTransaction.commitTransaction(); + LOG.info( + "Successfully created Iceberg table {} from delta lake table at {}, total data file count: {}", + newTableIdentifier, + deltaTableLocation, + totalDataFiles); + return new BaseSnapshotDeltaLakeTableActionResult(totalDataFiles); + } + + private Schema convertDeltaLakeSchema(io.delta.standalone.types.StructType deltaSchema) { + Type converted = + DeltaLakeDataTypeVisitor.visit(deltaSchema, new DeltaLakeTypeToType(deltaSchema)); + return new Schema(converted.asNestedType().asStructType().fields()); + } + + private PartitionSpec getPartitionSpecFromDeltaSnapshot(Schema schema) { + List<String> partitionNames = deltaLog.snapshot().getMetadata().getPartitionColumns(); + if (partitionNames.isEmpty()) { + return PartitionSpec.unpartitioned(); + } + + PartitionSpec.Builder builder = PartitionSpec.builderFor(schema); + for (String partitionName : partitionNames) { + builder.identity(partitionName); + } + return builder.build(); + } + + /** + * Iterate through the {@code VersionLog} to determine the update type and commit the update to + * the given {@code Transaction}. + * + * <p>There are 3 cases: + * + * <p>1. AppendFiles - when there are only AddFile instances (an INSERT on the table) + * + * <p>2. DeleteFiles - when there are only RemoveFile instances (a DELETE where all the records of + * file(s) were removed) + * + * <p>3. OverwriteFiles - when there are a mix of AddFile and RemoveFile (a DELETE/UPDATE) + * + * @param versionLog the delta log version to commit to iceberg table transaction + * @param transaction the iceberg table transaction to commit to + */ + private void commitDeltaVersionLogToIcebergTransaction( + VersionLog versionLog, Transaction transaction) { + List<Action> dataFileActions; + if (versionLog.getVersion() == deltaStartVersion) { + // The first version log is a special case, since it contains the initial table state. + // we need to get all dataFiles from the corresponding delta snapshot to construct the table. + dataFileActions = + deltaLog.getSnapshotForVersionAsOf(deltaStartVersion).getAllFiles().stream() + .map(addFile -> (Action) addFile) + .collect(Collectors.toList()); Review Comment: It is more logically reasonable to extract the datafiles from the snapshot for the start version instead of from the version log, since there may be versions already deleted from the table. Also, doing this also allow us to add options to let users choose which version to start snapshot. -- 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
