spark/v3.5/spark/src/main/java/org/apache/iceberg/spark/source/RowDataReader.java

/*
 * 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.spark.source;

import java.util.Map;
import java.util.stream.Stream;
import org.apache.iceberg.ContentFile;
import org.apache.iceberg.DataTask;
import org.apache.iceberg.FileScanTask;
import org.apache.iceberg.ScanTaskGroup;
import org.apache.iceberg.Schema;
import org.apache.iceberg.Table;
import org.apache.iceberg.io.CloseableIterable;
import org.apache.iceberg.io.CloseableIterator;
import org.apache.iceberg.io.InputFile;
import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
import org.apache.iceberg.spark.source.metrics.TaskNumDeletes;
import org.apache.iceberg.spark.source.metrics.TaskNumSplits;
import org.apache.iceberg.util.SnapshotUtil;
import org.apache.spark.rdd.InputFileBlockHolder;
import org.apache.spark.sql.catalyst.InternalRow;
import org.apache.spark.sql.connector.metric.CustomTaskMetric;
import org.apache.spark.sql.connector.read.PartitionReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

class RowDataReader extends BaseRowReader<FileScanTask> implements PartitionReader<InternalRow> {
  private static final Logger LOG = LoggerFactory.getLogger(RowDataReader.class);

  private final long numSplits;

  RowDataReader(SparkInputPartition partition) {
    this(
        partition.table(),
        partition.taskGroup(),
        SnapshotUtil.schemaFor(partition.table(), partition.branch()),
        partition.expectedSchema(),
        partition.isCaseSensitive());
  }

  RowDataReader(
      Table table,
      ScanTaskGroup<FileScanTask> taskGroup,
      Schema tableSchema,
      Schema expectedSchema,
      boolean caseSensitive) {

    super(table, taskGroup, tableSchema, expectedSchema, caseSensitive);

    numSplits = taskGroup.tasks().size();
    LOG.debug("Reading {} file split(s) for table {}", numSplits, table.name());
  }

  @Override
  public CustomTaskMetric[] currentMetricsValues() {
    return new CustomTaskMetric[] {
      new TaskNumSplits(numSplits), new TaskNumDeletes(counter().get())
    };
  }

  @Override
  protected Stream<ContentFile<?>> referencedFiles(FileScanTask task) {
    return Stream.concat(Stream.of(task.file()), task.deletes().stream());
  }

  @Override
  protected CloseableIterator<InternalRow> open(FileScanTask task) {
    String filePath = task.file().path().toString();
    LOG.debug("Opening data file {}", filePath);
    SparkDeleteFilter deleteFilter = new SparkDeleteFilter(filePath, task.deletes(), counter());

    // schema or rows returned by readers
    Schema requiredSchema = deleteFilter.requiredSchema();
    Map<Integer, ?> idToConstant = constantsMap(task, requiredSchema);

    // update the current file for Spark's filename() function
    InputFileBlockHolder.set(filePath, task.start(), task.length());

    return deleteFilter.filter(open(task, requiredSchema, idToConstant)).iterator();
  }

  protected CloseableIterable<InternalRow> open(
      FileScanTask task, Schema readSchema, Map<Integer, ?> idToConstant) {
    if (task.isDataTask()) {
      return newDataIterable(task.asDataTask(), readSchema);
    } else {
      InputFile inputFile = getInputFile(task.file().path().toString());
      Preconditions.checkNotNull(
          inputFile, "Could not find InputFile associated with FileScanTask");
      return newIterable(
          inputFile,
          task.file().format(),
          task.start(),
          task.length(),
          task.residual(),
          readSchema,
          idToConstant);
    }
  }

  private CloseableIterable<InternalRow> newDataIterable(DataTask task, Schema readSchema) {
    StructInternalRow row = new StructInternalRow(readSchema.asStruct());
    return CloseableIterable.transform(task.asDataTask().rows(), row::setStruct);
  }
}