rdblue commented on a change in pull request #843: [WIP] InputFormat support for Iceberg URL: https://github.com/apache/incubator-iceberg/pull/843#discussion_r393227120
########## File path: mr/src/main/java/org/apache/iceberg/mr/IcebergInputFormat.java ########## @@ -0,0 +1,345 @@ +/* + * 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.mr; + +import com.google.common.collect.Iterators; +import com.google.common.collect.Lists; +import java.io.Closeable; +import java.io.DataInput; +import java.io.DataOutput; +import java.io.IOException; +import java.util.Iterator; +import java.util.List; +import java.util.Set; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.io.Writable; +import org.apache.hadoop.mapreduce.InputFormat; +import org.apache.hadoop.mapreduce.InputSplit; +import org.apache.hadoop.mapreduce.JobContext; +import org.apache.hadoop.mapreduce.RecordReader; +import org.apache.hadoop.mapreduce.TaskAttemptContext; +import org.apache.iceberg.CombinedScanTask; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SchemaParser; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableScan; +import org.apache.iceberg.avro.Avro; +import org.apache.iceberg.catalog.Catalog; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.common.DynClasses; +import org.apache.iceberg.exceptions.RuntimeIOException; +import org.apache.iceberg.expressions.Expression; +import org.apache.iceberg.hadoop.HadoopInputFile; +import org.apache.iceberg.hadoop.HadoopTables; +import org.apache.iceberg.hive.HiveCatalogs; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.InputFile; +import org.apache.iceberg.orc.ORC; +import org.apache.iceberg.parquet.Parquet; +import org.apache.iceberg.types.TypeUtil; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +public class IcebergInputFormat<T> extends InputFormat<Void, T> { + private static final Logger LOG = LoggerFactory.getLogger(IcebergInputFormat.class); + + static final String FILTER_EXPRESSION = "iceberg.mr.filter.expression"; + static final String TABLE_SCHEMA = "iceberg.mr.table.schema"; + static final String TABLE_PATH = "iceberg.mr.table.path"; + static final String READ_SCHEMA = "iceberg.mr.read.schema"; + static final String READ_SUPPORT = "iceberg.mr.read.support"; + + private transient Table table; + private transient List<InputSplit> splits; + + public IcebergInputFormat() { + } + + @Override + public List<InputSplit> getSplits(JobContext context) { + if (splits != null) { + LOG.info("Returning cached splits: {}", splits.size()); + return splits; + } + + Configuration conf = context.getConfiguration(); + table = getTable(conf); + TableScan scan = table.newScan(); + //TODO add caseSensitive, snapshot id etc.. + + Expression filterExpression = SerializationUtil.deserializeFromBase64(conf.get(FILTER_EXPRESSION)); + if (filterExpression != null) { + scan = scan.filter(filterExpression); + } + + final String schemaStr = conf.get(READ_SCHEMA); + if (schemaStr != null) { + // Not sure if this is having any effect? + scan.project(SchemaParser.fromJson(schemaStr)); + } + + splits = Lists.newArrayList(); + try (CloseableIterable<CombinedScanTask> tasksIterable = scan.planTasks()) { + tasksIterable.forEach(task -> splits.add(new IcebergSplit(task))); + } catch (IOException e) { + throw new RuntimeIOException(e, "Failed to close table scan: %s", scan); + } + + return splits; + } + + @Override + public RecordReader<Void, T> createRecordReader(InputSplit split, TaskAttemptContext context) { + return new IcebergRecordReader(); + } + + public static ConfBuilder updateConf( Review comment: I like the builder pattern here. I used something similar for Kite's `InputFormat`. You might consider how that builder worked. The static methods there would [accept a `Job` when creating the builder](https://github.com/kite-sdk/kite/blob/master/kite-data/kite-data-mapreduce/src/main/java/org/kitesdk/data/mapreduce/DatasetKeyInputFormat.java#L191-L203). That way, there was no need for the user to also set the input format class. It was also not necessary to build the resulting `Configuration` and do something with it: ```java /** * Configures the {@code Job} to use the {@code IcebergInputFormat} and * returns a helper to add further configuration. * * @param job the {@code Job} to configure */ public static ConfigBuilder configure(Job job) { job.setInputFormatClass(IcebergInputFormat.class); return new ConfigBuilder(job.getConfiguration()); } ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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