vvysotskyi commented on a change in pull request #1799: DRILL-7251: Read Hive array w/o nulls URL: https://github.com/apache/drill/pull/1799#discussion_r289390310
########## File path: contrib/storage-hive/core/src/main/java/org/apache/drill/exec/store/hive/readers/HiveDefaultRecordReader.java ########## @@ -0,0 +1,522 @@ +/* + * 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.drill.exec.store.hive.readers; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.Properties; +import java.util.concurrent.Callable; +import java.util.concurrent.ExecutionException; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +import io.netty.buffer.DrillBuf; +import org.apache.drill.common.exceptions.DrillRuntimeException; +import org.apache.drill.common.exceptions.ExecutionSetupException; +import org.apache.drill.common.expression.PathSegment; +import org.apache.drill.common.expression.SchemaPath; +import org.apache.drill.common.types.TypeProtos; +import org.apache.drill.exec.expr.TypeHelper; +import org.apache.drill.exec.ops.FragmentContext; +import org.apache.drill.exec.ops.OperatorContext; +import org.apache.drill.exec.physical.impl.OutputMutator; +import org.apache.drill.exec.record.MaterializedField; +import org.apache.drill.exec.server.options.OptionManager; +import org.apache.drill.exec.store.AbstractRecordReader; +import org.apache.drill.exec.store.hive.HivePartition; +import org.apache.drill.exec.store.hive.HiveTableWithColumnCache; +import org.apache.drill.exec.store.hive.HiveUtilities; +import org.apache.drill.exec.store.hive.writers.HiveValueWriter; +import org.apache.drill.exec.store.hive.writers.HiveValueWriterFactory; +import org.apache.drill.exec.vector.AllocationHelper; +import org.apache.drill.exec.vector.ValueVector; +import org.apache.drill.exec.vector.complex.impl.VectorContainerWriter; +import org.apache.drill.shaded.guava.com.google.common.util.concurrent.ListenableFuture; +import org.apache.hadoop.hive.conf.HiveConf; +import org.apache.hadoop.hive.metastore.api.FieldSchema; +import org.apache.hadoop.hive.metastore.api.StorageDescriptor; +import org.apache.hadoop.hive.serde2.ColumnProjectionUtils; +import org.apache.hadoop.hive.serde2.Deserializer; +import org.apache.hadoop.hive.serde2.SerDeException; +import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; +import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters; +import org.apache.hadoop.hive.serde2.objectinspector.StructField; +import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector; +import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo; +import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo; +import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils; +import org.apache.hadoop.io.Writable; +import org.apache.hadoop.mapred.InputSplit; +import org.apache.hadoop.mapred.JobConf; +import org.apache.hadoop.mapred.RecordReader; +import org.apache.hadoop.mapred.Reporter; +import org.apache.hadoop.security.UserGroupInformation; + +/** + * Reader which uses complex writer underneath to fill in value vectors with data read from Hive. + * At first glance initialization code in the writer looks cumbersome, but in the end it's main aim is to prepare list of key + * fields used in next() and readHiveRecordAndInsertIntoRecordBatch(Object rowValue) methods. + * <p> + * In a nutshell, the reader is used in two stages: + * 1) Setup stage configures mapredReader, partitionObjInspector, partitionDeserializer, list of {@link HiveValueWriter}s for each column in record + * batch, partition vectors and values + * 2) Reading stage uses objects configured previously to get rows from InputSplits, represent each row as Struct of columns values, + * and write each row value of column into Drill's value vectors using HiveValueWriter for each specific column + */ +public class HiveDefaultRecordReader extends AbstractRecordReader { + + protected static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(HiveDefaultRecordReader.class); + + /** + * Max amount of records that can be consumed by one next() method call + */ + public static final int TARGET_RECORD_COUNT = 4000; + + /** + * Key of partition columns in grouped map. + */ + private static final boolean PARTITION_COLUMNS = true; + + /** + * Manages all writes to value vectors received using OutputMutator + */ + protected VectorContainerWriter outputWriter; + + /** + * Before creation of mapredReader Drill creates the object which holds + * meta about table that should be read. + */ + private final HiveTableWithColumnCache hiveTable; + + /** + * Contains info about current user and group. Used to initialize + * the mapredReader using under the user permissions. + */ + private final UserGroupInformation proxyUserGroupInfo; + + /** + * Config to be used for creation of JobConf instance. + */ + private final HiveConf hiveConf; + + /** + * Hive partition wrapper with index of column list in ColumnListsCache. + */ + private final HivePartition partition; + + /** + * This mapredReader creates JobConf instance to use it's handsome metadata. + * Actually the job won't be executed. + */ + private JobConf job; + + /** + * Deserializer to be used for deserialization of row. + * Depending on partition presence it may be partition or table deserializer. + */ + protected Deserializer partitionDeserializer; + + /** + * Used to inspect rows parsed by partitionDeserializer + */ + private StructObjectInspector partitionObjInspector; + + /** + * Converts value deserialized using partitionDeserializer + */ + protected ObjectInspectorConverters.Converter partitionToTableSchemaConverter; + + /** + * Used to inspect rowValue of each column + */ + private StructObjectInspector finalObjInspector; + + /** + * For each concrete column to be read we assign concrete writer + * which encapsulates writing of column values read from Hive into + * specific value vector + */ + private HiveValueWriter[] columnValueWriters; + + /** + * At the moment of mapredReader instantiation we can check inputSplits, + * if splits aren't present than there are no records to read, + * so mapredReader can finish work early. + */ + protected boolean empty; + + /** + * Buffer used for population of partition vectors and to fill in data into vectors via writers + */ + private final DrillBuf drillBuf; + + /** + * The fragmentContext holds different helper objects + * associated with fragment. In the reader it's used + * to get options for accurate detection of partition columns types. + */ + private final FragmentContext fragmentContext; + + /** + * Partition vectors and values are linked together and gets filled after we know that all records are read. + * This two arrays must have same sizes. + */ + private ValueVector[] partitionVectors; + + /** + * Values to be written into partition vector. + */ + private Object[] partitionValues; + + + /** + * InputSplits to be processed by mapredReader. + */ + private final Iterator<InputSplit> inputSplitsIterator; + + /** + * Reader used to to get data from InputSplits + */ + protected RecordReader<Object, Object> mapredReader; + + /** + * Helper object used together with mapredReader to get data from InputSplit. + */ + private Object key; + + /** + * Helper object used together with mapredReader to get data from InputSplit. + */ + protected Object valueHolder; + + /** + * Array of StructField representing columns to be read by the reader. + * Used to extract row value of column from final object inspector. + */ + private StructField[] selectedStructFieldRefs; + + + /** + * Readers constructor called by initializer. + * + * @param table metadata about Hive table being read + * @param partition holder of metadata about table partitioning + * @param inputSplits input splits for reading data from distributed storage + * @param projectedColumns target columns for scan + * @param context fragmentContext of fragment + * @param hiveConf Hive configuration + * @param proxyUgi user/group info to be used for initialization + */ + public HiveDefaultRecordReader(HiveTableWithColumnCache table, HivePartition partition, + Collection<InputSplit> inputSplits, List<SchemaPath> projectedColumns, + FragmentContext context, HiveConf hiveConf, UserGroupInformation proxyUgi) { + this.hiveTable = table; + this.partition = partition; + this.hiveConf = hiveConf; + this.proxyUserGroupInfo = proxyUgi; + this.empty = inputSplits == null || inputSplits.isEmpty(); + this.inputSplitsIterator = empty ? Collections.emptyIterator() : inputSplits.iterator(); + this.drillBuf = context.getManagedBuffer().reallocIfNeeded(256); + this.partitionVectors = new ValueVector[0]; + this.partitionValues = new Object[0]; + setColumns(projectedColumns); + this.fragmentContext = context; + } + + @Override + public void setup(OperatorContext context, OutputMutator output) throws ExecutionSetupException { + Callable<Void> userSpecificInitTask = () -> { + this.job = new JobConf(hiveConf); + Properties hiveTableProperties = HiveUtilities.getTableMetadata(hiveTable); + final Deserializer tableDeserializer = createDeserializer(job, hiveTable.getSd(), hiveTableProperties); + final StructObjectInspector tableObjInspector = getStructOI(tableDeserializer); + + if (partition == null) { + this.partitionDeserializer = tableDeserializer; + this.partitionObjInspector = tableObjInspector; + this.partitionToTableSchemaConverter = (obj) -> obj; + this.finalObjInspector = tableObjInspector; + + job.setInputFormat(HiveUtilities.getInputFormatClass(job, hiveTable.getSd(), hiveTable)); + HiveUtilities.verifyAndAddTransactionalProperties(job, hiveTable.getSd()); + } else { + this.partitionDeserializer = createDeserializer(job, partition.getSd(), HiveUtilities.getPartitionMetadata(partition, hiveTable)); + this.partitionObjInspector = getStructOI(partitionDeserializer); + + this.finalObjInspector = (StructObjectInspector) ObjectInspectorConverters.getConvertedOI(partitionObjInspector, tableObjInspector); + this.partitionToTableSchemaConverter = ObjectInspectorConverters.getConverter(partitionObjInspector, finalObjInspector); + + this.job.setInputFormat(HiveUtilities.getInputFormatClass(job, partition.getSd(), hiveTable)); + HiveUtilities.verifyAndAddTransactionalProperties(job, partition.getSd()); + } + + + final List<FieldSchema> partitionKeyFields = hiveTable.getPartitionKeys(); + final List<String> partitionColumnNames = partitionKeyFields.stream().map(FieldSchema::getName).collect(Collectors.toList()); + final List<String> allTableColumnNames = ((StructTypeInfo) TypeInfoUtils.getTypeInfoFromObjectInspector(finalObjInspector)).getAllStructFieldNames(); Review comment: Could you please add a comment back? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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