rdblue commented on a change in pull request #843: [WIP] InputFormat support for Iceberg URL: https://github.com/apache/incubator-iceberg/pull/843#discussion_r393221137
########## 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( + Configuration conf, String path, Class<? extends ReadSupport<?>> readSupportClass) { + return new ConfBuilder(conf, path, readSupportClass); + } + + public static class ConfBuilder { + private final Configuration conf; + + public ConfBuilder(Configuration conf, String path, Class<? extends ReadSupport<?>> readSupportClass) { + this.conf = conf; + conf.set(TABLE_PATH, path); + conf.set(READ_SUPPORT, readSupportClass.getName()); + Table table = getTable(conf); + conf.set(TABLE_SCHEMA, SchemaParser.toJson(table.schema())); + } + + public ConfBuilder filterExpression(Expression expression) throws IOException { + conf.set(FILTER_EXPRESSION, SerializationUtil.serializeToBase64(expression)); + return this; + } + + public ConfBuilder project(Schema schema) { + conf.set(READ_SCHEMA, SchemaParser.toJson(schema)); + return this; + } + + //TODO: other options split-size, snapshotid etc.. + public Configuration updatedConf() { + return conf; + } + } + + private static final class IcebergRecordReader<T> extends RecordReader<Void, T> { + private TaskAttemptContext context; + private Iterator<FileScanTask> tasks; + private Iterator<T> currentIterator; + private T currentRow; + private Schema expectedSchema; + private Schema tableSchema; + private ReadSupport<T> readSupport; + private Closeable currentCloseable; + + @Override + public void initialize(InputSplit split, TaskAttemptContext context) { + Configuration conf = context.getConfiguration(); + CombinedScanTask task = ((IcebergSplit) split).task; + this.context = context; + this.tasks = task.files().iterator(); + this.tableSchema = SchemaParser.fromJson(conf.get(TABLE_SCHEMA)); + String readSchemaStr = conf.get(READ_SCHEMA); + if (readSchemaStr != null) { + this.expectedSchema = SchemaParser.fromJson(readSchemaStr); + } + this.readSupport = readSupport(conf); + this.currentIterator = open(tasks.next()); + } + + @Override + public boolean nextKeyValue() throws IOException { + while (true) { + if (currentIterator.hasNext()) { + currentRow = currentIterator.next(); + return true; + } else if (tasks.hasNext()) { + currentCloseable.close(); + currentIterator = open(tasks.next()); + } else { + return false; + } + } + } + + @Override + public Void getCurrentKey() { + return null; + } + + @Override + public T getCurrentValue() { + return currentRow; + } + + @Override + public float getProgress() { + return context.getProgress(); + } + + @Override + public void close() throws IOException { + currentCloseable.close(); + } + + private ReadSupport<T> readSupport(Configuration conf) { + String readSupportClassName = conf.get(READ_SUPPORT); + try { + return DynClasses + .builder() + .impl(readSupportClassName) + .<ReadSupport<T>>buildChecked() + .newInstance(); + } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) { + throw new RuntimeException(String.format("Unable to instantiate read support %s", readSupportClassName), e); + } + } + + private Iterator<T> open(FileScanTask currentTask) { + DataFile file = currentTask.file(); + // schema of rows returned by readers + PartitionSpec spec = currentTask.spec(); + Set<Integer> idColumns = spec.identitySourceIds(); + + boolean hasJoinedPartitionColumns = !idColumns.isEmpty(); + Schema readSchema = expectedSchema != null ? expectedSchema : tableSchema; + if (hasJoinedPartitionColumns) { + readSchema = TypeUtil.selectNot(tableSchema, idColumns); + Schema partitionSchema = TypeUtil.select(tableSchema, idColumns); + return Iterators.transform( + open(currentTask, readSchema), + row -> readSupport.withPartitionColumns(row, partitionSchema, spec, file.partition())); + } else { + return open(currentTask, readSchema); + } + } + + private Iterator<T> open(FileScanTask currentTask, Schema readSchema) { Review comment: Yeah, there may be a good way to extract common code. For now, let's do that in a separate PR though to keep this focused on the MR support. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
