anuragmantri commented on code in PR #14948: URL: https://github.com/apache/iceberg/pull/14948#discussion_r3993155994
########## spark/v4.1/spark/src/test/java/org/apache/iceberg/spark/source/TestMergingSortedRowDataReader.java: ########## @@ -0,0 +1,718 @@ +/* + * 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 static org.apache.iceberg.types.Types.NestedField.required; +import static org.assertj.core.api.Assertions.assertThat; +import static org.assertj.core.api.Assertions.assertThatThrownBy; +import static org.mockito.Mockito.doReturn; +import static org.mockito.Mockito.when; + +import java.io.File; +import java.io.IOException; +import java.nio.file.Path; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.UUID; +import java.util.function.Function; +import java.util.stream.Stream; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.Files; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableUtil; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.data.FileHelpers; +import org.apache.iceberg.data.GenericRecord; +import org.apache.iceberg.data.Record; +import org.apache.iceberg.expressions.Expressions; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.TestBase; +import org.apache.iceberg.transforms.Transform; +import org.apache.iceberg.transforms.Transforms; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Pair; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.io.TempDir; +import org.mockito.Mockito; + +class TestMergingSortedRowDataReader extends TestBase { + + private static final Schema SCHEMA = + new Schema( + required(1, "id", Types.IntegerType.get()), required(2, "data", Types.StringType.get())); + + private static final PartitionSpec SPEC = PartitionSpec.unpartitioned(); + + private Table table; + + @TempDir private Path temp; + + @BeforeEach + void before() { + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + table.replaceSortOrder().asc("id").commit(); + } + + @AfterEach + void after() { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + } + + @Test + void mergeTwoSortedFiles() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c"), record(5, "e")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d"), record(6, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 2, 3, 4, 5, 6); + } + + @Test + void mergeWithDuplicateKeys() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(2, "b")); + DataFile file2 = writeDataFile(record(1, "c"), record(2, "d")); + DataFile file3 = writeDataFile(record(1, "e"), record(3, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).appendFile(file3).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 1, 1, 2, 2, 3); + } + + @Test + void mergeDescendingOrder() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); Review Comment: I removed this used afterEach. ########## spark/v4.1/spark/src/test/java/org/apache/iceberg/spark/source/TestMergingSortedRowDataReader.java: ########## @@ -0,0 +1,718 @@ +/* + * 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 static org.apache.iceberg.types.Types.NestedField.required; +import static org.assertj.core.api.Assertions.assertThat; +import static org.assertj.core.api.Assertions.assertThatThrownBy; +import static org.mockito.Mockito.doReturn; +import static org.mockito.Mockito.when; + +import java.io.File; +import java.io.IOException; +import java.nio.file.Path; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.UUID; +import java.util.function.Function; +import java.util.stream.Stream; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.Files; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableUtil; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.data.FileHelpers; +import org.apache.iceberg.data.GenericRecord; +import org.apache.iceberg.data.Record; +import org.apache.iceberg.expressions.Expressions; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.TestBase; +import org.apache.iceberg.transforms.Transform; +import org.apache.iceberg.transforms.Transforms; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Pair; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.io.TempDir; +import org.mockito.Mockito; + +class TestMergingSortedRowDataReader extends TestBase { + + private static final Schema SCHEMA = + new Schema( + required(1, "id", Types.IntegerType.get()), required(2, "data", Types.StringType.get())); + + private static final PartitionSpec SPEC = PartitionSpec.unpartitioned(); + + private Table table; + + @TempDir private Path temp; + + @BeforeEach + void before() { + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + table.replaceSortOrder().asc("id").commit(); + } + + @AfterEach + void after() { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + } + + @Test + void mergeTwoSortedFiles() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c"), record(5, "e")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d"), record(6, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 2, 3, 4, 5, 6); + } + + @Test + void mergeWithDuplicateKeys() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(2, "b")); + DataFile file2 = writeDataFile(record(1, "c"), record(2, "d")); + DataFile file3 = writeDataFile(record(1, "e"), record(3, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).appendFile(file3).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 1, 1, 2, 2, 3); + } + + @Test + void mergeDescendingOrder() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + table.replaceSortOrder().desc("id").commit(); + + DataFile file1 = writeDataFile(record(6, "f"), record(4, "d")); + DataFile file2 = writeDataFile(record(5, "e"), record(3, "c"), record(1, "a")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(6, 5, 4, 3, 1); + } + + @Test + void mergeWithNulls() throws IOException { + Schema nullableSchema = + new Schema( + Types.NestedField.optional(1, "id", Types.IntegerType.get()), + required(2, "data", Types.StringType.get())); + + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + table = + catalog.createTable( + TableIdentifier.of("default", "test_merging_reader"), nullableSchema, SPEC); + table.replaceSortOrder().asc("id").commit(); + + DataFile file1 = writeDataFile(nullRecord("x"), record(3, "c")); + DataFile file2 = writeDataFile(nullRecord("y"), record(1, "a"), record(2, "b")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(rows).hasSize(5); + assertThat(rows.get(0).isNullAt(0)).isTrue(); + assertThat(rows.get(1).isNullAt(0)).isTrue(); + assertThat(extractIds(rows.subList(2, 5))).containsExactly(1, 2, 3); + } + + @Test + void mergeThreeFiles() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(4, "d"), record(7, "g")); + DataFile file2 = writeDataFile(record(2, "b"), record(5, "e"), record(8, "h")); + DataFile file3 = writeDataFile(record(3, "c"), record(6, "f"), record(9, "i")); + + table.newAppend().appendFile(file1).appendFile(file2).appendFile(file3).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 2, 3, 4, 5, 6, 7, 8, 9); + } + + @Test + void mergeWithSortKeyNotInProjection() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c"), record(5, "e")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d"), record(6, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + // Project only "data". The sort key "id" is missing from the projection, so it is added to + // the read schema for the merge comparator and stripped from the rows returned to Spark. + Schema dataOnly = table.schema().select("data"); + List<InternalRow> rows = readMerged(table, dataOnly); + + // Rows come back ordered by id even though id is not projected. + assertThat(extractData(rows, 0)).containsExactly("a", "b", "c", "d", "e", "f"); + // Only the projected column is present in the returned rows. + assertThat(rows.get(0).numFields()).isEqualTo(1); + } + + @Test + void mergeAfterSortOrderEvolution() throws IOException { + // Evolve the sort order from "id" to "data". The reader should merge by the current order. + table.replaceSortOrder().asc("data").commit(); + + DataFile file1 = writeDataFile(record(5, "a"), record(3, "c"), record(1, "e")); + DataFile file2 = writeDataFile(record(6, "b"), record(4, "d"), record(2, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + // Ordered by data, not by id. + assertThat(extractData(rows, 1)).containsExactly("a", "b", "c", "d", "e", "f"); + } + + @Test + void mergeWithStructColumnNotInSortOrder() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + + Schema schemaWithStruct = + new Schema( + required(1, "id", Types.IntegerType.get()), + required(2, "data", Types.StringType.get()), + required( + 4, "location", Types.StructType.of(required(5, "city", Types.StringType.get())))); + + table = + catalog.createTable( + TableIdentifier.of("default", "test_merging_reader"), schemaWithStruct, SPEC); + table.replaceSortOrder().asc("id").commit(); + + DataFile file1 = writeDataFile(structRecord(1, "a", "NYC"), structRecord(3, "c", "SFO")); + DataFile file2 = writeDataFile(structRecord(2, "b", "LAX"), structRecord(4, "d", "SEA")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + // Project the struct but not the sort key, so the merge schema is widened around a struct. + Schema projection = table.schema().select("location"); + List<InternalRow> rows = readMerged(table, projection); + + assertThat(rows.get(0).numFields()).isEqualTo(1); + assertThat(rows.stream().map(row -> row.getStruct(0, 1).getUTF8String(0).toString()).toList()) + .containsExactly("NYC", "LAX", "SFO", "SEA"); + } + + @Test + void mergeRejectsStaleSortOrderId() throws IOException { + SortOrder oldSortOrder = table.sortOrder(); + + // file1 keeps the old order id, file2 is written with the evolved one + DataFile file1 = + DataFiles.builder(table.spec()) + .copy(writeRecords(record(1, "a"), record(3, "c"))) + .withSortOrder(oldSortOrder) + .build(); + + table.replaceSortOrder().asc("data").commit(); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + assertThatThrownBy(() -> readMerged(table)) + .isInstanceOf(IllegalArgumentException.class) + .hasMessageContaining("Not all files in task group have the expected sort order"); + } + + @Test + void mergeRejectsMissingSortOrderId() { + // sort_order_id is optional in the manifest schema, so a file may report null + ScanTaskGroup<FileScanTask> taskGroup = + taskGroupWithSortOrderIds(table.sortOrder().orderId(), null); + + assertThatThrownBy( + () -> + new MergingSortedRowDataReader( + table, table.io(), taskGroup, table.schema(), true, false)) + .isInstanceOf(IllegalArgumentException.class) + .hasMessageContaining("Not all files in task group have the expected sort order"); + } + + @Test + void mergeRejectsSingleFile() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c")); + + table.newAppend().appendFile(file1).commit(); + table.refresh(); + + BaseScanTaskGroup<FileScanTask> taskGroup = new BaseScanTaskGroup<>(planFiles(table)); + + assertThatThrownBy( + () -> + new MergingSortedRowDataReader( + table, table.io(), taskGroup, table.schema(), true, false)) + .isInstanceOf(IllegalArgumentException.class) + .hasMessageContaining("Merging reader requires multiple files, got 1"); + } + + @Test + void mergeRejectsUnsortedTable() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + table.refresh(); + + BaseScanTaskGroup<FileScanTask> taskGroup = new BaseScanTaskGroup<>(planFiles(table)); + + assertThatThrownBy( + () -> + new MergingSortedRowDataReader( + table, table.io(), taskGroup, table.schema(), true, false)) + .isInstanceOf(IllegalArgumentException.class) + .hasMessageContaining("Cannot create merging reader for unsorted table"); + } + + @Test + void mergeWithFileFullyRemovedByDeletes() throws IOException { + // SortedMerge drops iterators that are empty on the first hasNext() without closing them, so a + // file whose rows are all deleted exercises the reader ownership documented in close(). + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + DeleteFile deleteFile = + FileHelpers.writeDeleteFile( + table, + Files.localOutput(File.createTempFile("junit", null, temp.toFile())), + Lists.newArrayList(Pair.of(file1.location(), 0L), Pair.of(file1.location(), 1L)), + TableUtil.formatVersion(table)) + .first(); + table.newRowDelta().addDeletes(deleteFile).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(2, 4); + } + + @Test + void mergeWithFileFullyRemovedByDeletesAmongMultipleFiles() throws IOException { + // With only two files, file1 draining leaves nothing to merge against. With three, file2 and + // file3 are still genuinely merged against each other after file1 drops out of the heap. + DataFile file1 = writeDataFile(record(1, "a"), record(4, "d")); + DataFile file2 = writeDataFile(record(2, "b"), record(5, "e")); + DataFile file3 = writeDataFile(record(3, "c"), record(6, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).appendFile(file3).commit(); + + DeleteFile deleteFile = + FileHelpers.writeDeleteFile( + table, + Files.localOutput(File.createTempFile("junit", null, temp.toFile())), + Lists.newArrayList(Pair.of(file1.location(), 0L), Pair.of(file1.location(), 1L)), + TableUtil.formatVersion(table)) + .first(); + table.newRowDelta().addDeletes(deleteFile).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(2, 3, 5, 6); + } + + @Test + void mergeWithPositionDeletes() throws IOException { + // File1: [1, 3, 5], File2: [2, 4, 6] + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c"), record(5, "e")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d"), record(6, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + // Delete the row at position 1 in file1 (value 3). + DeleteFile deleteFile = + FileHelpers.writeDeleteFile( + table, + Files.localOutput(File.createTempFile("junit", null, temp.toFile())), + Lists.newArrayList(Pair.of(file1.location(), 1L)), + TableUtil.formatVersion(table)) + .first(); + table.newRowDelta().addDeletes(deleteFile).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 2, 4, 5, 6); + } + + @Test + void mergeWithSortOrderReferencingSameColumnMultipleTimes() throws IOException { + table.replaceSortOrder().asc(Expressions.bucket("id", 16)).asc("id").commit(); + + List<Record> sorted = recordsInBucketThenIdOrder(); + List<Record> left = Lists.newArrayList(); + List<Record> right = Lists.newArrayList(); + for (int i = 0; i < sorted.size(); i++) { + (i % 2 == 0 ? left : right).add(sorted.get(i)); + } + + DataFile file1 = writeDataFile(left.toArray(new Record[0])); + DataFile file2 = writeDataFile(right.toArray(new Record[0])); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + // the sort key "id" is not in the projection and is referenced by two sort fields. + Schema dataOnly = table.schema().select("data"); + List<InternalRow> rows = readMerged(table, dataOnly); + + assertThat(rows.get(0).numFields()).isEqualTo(1); + assertThat(extractData(rows, 0)) + .containsExactlyElementsOf(sorted.stream().map(rec -> (String) rec.get(1)).toList()); + } + + private List<Record> recordsInBucketThenIdOrder() { + Transform<Integer, Integer> bucket = Transforms.bucket(16); + Function<Integer, Integer> toBucket = bucket.bind(Types.IntegerType.get())::apply; + + return Stream.of( + record(1, "a"), + record(2, "b"), + record(3, "c"), + record(4, "d"), + record(5, "e"), + record(6, "f")) + .sorted( + Comparator.<Record, Integer>comparing(rec -> toBucket.apply((Integer) rec.get(0))) + .thenComparing(rec -> (Integer) rec.get(0))) + .toList(); + } + + @Test + void inputFileBlockHolderReportsCorrectFile() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + BaseScanTaskGroup<FileScanTask> taskGroup = new BaseScanTaskGroup<>(planFiles(table)); + + // Track which file each row reports via InputFileBlockHolder + List<String> reportedFiles = Lists.newArrayList(); + List<Integer> ids = Lists.newArrayList(); + try (MergingSortedRowDataReader reader = + new MergingSortedRowDataReader(table, table.io(), taskGroup, table.schema(), true, false)) { + while (reader.next()) { + reportedFiles.add(InputFileBlockHolder.getInputFilePath().toString()); + ids.add(reader.get().getInt(0)); + } + } + + // Rows should be interleaved: 1 (file1), 2 (file2), 3 (file1), 4 (file2) + assertThat(ids).containsExactly(1, 2, 3, 4); + + // Each row must report its actual source file, not just the last-opened file + String file1Location = file1.location(); + String file2Location = file2.location(); + + Map<String, String> idToExpectedFile = + Map.of( + "1", file1Location, + "3", file1Location, + "2", file2Location, + "4", file2Location); + + for (int i = 0; i < ids.size(); i++) { + assertThat(reportedFiles.get(i)) + .as( + "Row with id=%d should report file %s", + ids.get(i), idToExpectedFile.get(ids.get(i).toString())) + .isEqualTo(idToExpectedFile.get(ids.get(i).toString())); + } + } + + @Test + void mergeWithNestedSortKeyInProjection() throws IOException { + BaseScanTaskGroup<FileScanTask> taskGroup = setUpNestedSortKeyTable(); + + List<InternalRow> rows = Lists.newArrayList(); + try (MergingSortedRowDataReader reader = + new MergingSortedRowDataReader(table, table.io(), taskGroup, table.schema(), true, false)) { + while (reader.next()) { + rows.add(reader.get().copy()); + } + } + + assertThat(rows.stream().map(row -> row.getStruct(1, 1).getUTF8String(0).toString()).toList()) + .containsExactly("LA", "NYC"); + } + + @Test + void mergeRejectsNestedSortKeyNotInProjection() throws IOException { + BaseScanTaskGroup<FileScanTask> taskGroup = setUpNestedSortKeyTable(); + + Schema idOnly = table.schema().select("id"); + + assertThatThrownBy( + () -> new MergingSortedRowDataReader(table, table.io(), taskGroup, idOnly, true, false)) + .isInstanceOf(IllegalArgumentException.class) + .hasMessageContaining("does not support sort keys on nested fields"); + } + + @Test + void mergeRejectsUuidSortKey() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + + Schema uuidSchema = + new Schema( + required(1, "id", Types.IntegerType.get()), required(2, "key", Types.UUIDType.get())); + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), uuidSchema); + table.replaceSortOrder().asc("key").commit(); + + // Iceberg's UUID#compareTo ordering and Spark's string-based UUID ordering disagree, so an + // identity sort key on a UUID column is rejected regardless of what wrote the files. + DataFile file1 = writeUuidRecords(uuidRecord(uuidSchema, 1, UUID.randomUUID())); + DataFile file2 = writeUuidRecords(uuidRecord(uuidSchema, 2, UUID.randomUUID())); + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + BaseScanTaskGroup<FileScanTask> taskGroup = new BaseScanTaskGroup<>(planFiles(table)); + + assertThatThrownBy( + () -> + new MergingSortedRowDataReader( + table, table.io(), taskGroup, table.schema(), true, false)) + .isInstanceOf(IllegalArgumentException.class) + .hasMessageContaining("does not support UUID-typed sort keys"); + } + + @Test + void mergeWithBucketedUuidSortKey() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + + Schema uuidSchema = + new Schema( + required(1, "id", Types.IntegerType.get()), required(2, "key", Types.UUIDType.get())); + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), uuidSchema); + table.replaceSortOrder().asc(Expressions.bucket("key", 8)).commit(); + + // bucket(key, 8) is unaffected by the guard: its result type is int, computed identically by + // Iceberg and Spark, so the merge does not need to compare raw UUID values. + DataFile file1 = + writeUuidRecords( + uuidRecord(uuidSchema, 1, UUID.randomUUID()), + uuidRecord(uuidSchema, 2, UUID.randomUUID())); + DataFile file2 = + writeUuidRecords( + uuidRecord(uuidSchema, 3, UUID.randomUUID()), + uuidRecord(uuidSchema, 4, UUID.randomUUID())); + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + BaseScanTaskGroup<FileScanTask> taskGroup = new BaseScanTaskGroup<>(planFiles(table)); + + List<Integer> ids = Lists.newArrayList(); + try (MergingSortedRowDataReader reader = + new MergingSortedRowDataReader(table, table.io(), taskGroup, table.schema(), true, false)) { + while (reader.next()) { + ids.add(reader.get().getInt(0)); + } + } + + assertThat(ids).containsExactlyInAnyOrder(1, 2, 3, 4); + } + + private Record uuidRecord(Schema uuidSchema, int id, UUID key) { + GenericRecord record = GenericRecord.create(uuidSchema); + record.set(0, id); + record.set(1, key); + return record; + } + + private DataFile writeUuidRecords(Record... records) throws IOException { + DataFile file = + FileHelpers.writeDataFile( + table, + Files.localOutput(File.createTempFile("junit", null, temp.toFile())), + Lists.newArrayList(records)); + return DataFiles.builder(table.spec()).copy(file).withSortOrder(table.sortOrder()).build(); + } + + private BaseScanTaskGroup<FileScanTask> setUpNestedSortKeyTable() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + + Schema nestedSchema = + new Schema( + required(1, "id", Types.IntegerType.get()), + required( + 2, "location", Types.StructType.of(required(3, "city", Types.StringType.get())))); + + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), nestedSchema); Review Comment: Done ########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/source/MergingSortedRowDataReader.java: ########## @@ -0,0 +1,358 @@ +/* + * 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.io.IOException; +import java.io.UncheckedIOException; +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Objects; +import org.apache.iceberg.Accessor; +import org.apache.iceberg.Accessors; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortField; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.SortOrderComparators; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.Table; +import org.apache.iceberg.io.CloseableGroup; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.CloseableIterator; +import org.apache.iceberg.io.FileIO; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.SparkSchemaUtil; +import org.apache.iceberg.spark.source.metrics.TaskNumDeletes; +import org.apache.iceberg.spark.source.metrics.TaskNumSplits; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.TypeUtil; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Exceptions; +import org.apache.iceberg.util.SortedMerge; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.apache.spark.sql.catalyst.ProjectingInternalRow; +import org.apache.spark.sql.catalyst.expressions.UnsafeProjection; +import org.apache.spark.sql.connector.metric.CustomTaskMetric; +import org.apache.spark.sql.connector.read.PartitionReader; +import org.apache.spark.sql.types.StructType; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import scala.collection.JavaConverters; + +/** + * A {@link PartitionReader} that reads multiple sorted files and merges them into a single sorted + * stream using a k-way heap merge ({@link SortedMerge}). + * + * <p>Every file in the task group must be written with the table's current sort order. Sort keys on + * nested fields are not supported. + */ +class MergingSortedRowDataReader implements PartitionReader<InternalRow> { + private static final Logger LOG = LoggerFactory.getLogger(MergingSortedRowDataReader.class); + + private final CloseableGroup resources; + private final CloseableIterator<TaggedRow> mergedIterator; + private final List<RowDataReader> fileReaders; + // non-null only when sort key columns were added to the read schema beyond what Spark projected + private final ProjectingInternalRow projectingRow; + private final UnsafeProjection deepCopyProjection; + private InternalRow current; + private FileBlock currentBlock; + + MergingSortedRowDataReader(SparkInputPartition partition) { + this( + partition.table(), + partition.io(), + partition.taskGroup(), + partition.projection(), + partition.isCaseSensitive(), + partition.cacheDeleteFilesOnExecutors()); + } + + MergingSortedRowDataReader( + Table table, + FileIO io, + ScanTaskGroup<FileScanTask> taskGroup, + Schema projection, + boolean caseSensitive, + boolean cacheDeleteFilesOnExecutors) { + SortOrder sortOrder = table.sortOrder(); + int numFiles = taskGroup.tasks().size(); + + Preconditions.checkArgument( + sortOrder.isSorted(), "Cannot create merging reader for unsorted table %s", table.name()); + Preconditions.checkArgument( + numFiles > 1, "Merging reader requires multiple files, got %s", numFiles); + + int expectedOrderId = sortOrder.orderId(); + Preconditions.checkArgument( + taskGroup.tasks().stream() + .allMatch(task -> Objects.equals(task.file().sortOrderId(), expectedOrderId)), + "Not all files in task group have the expected sort order %s", + expectedOrderId); + + LOG.debug( + "Creating merging reader for {} files with sort order {} in table {}", + numFiles, + sortOrder.orderId(), + table.name()); + + // Augment the projected schema with any sort key columns Spark did not request so that + // SortOrderComparators can access every sort key field during the merge. + Schema mergeReadSchema = mergeReadSchema(projection, sortOrder, table); + this.projectingRow = buildProjectingRow(projection, mergeReadSchema); + this.deepCopyProjection = UnsafeProjection.create(SparkSchemaUtil.convert(mergeReadSchema)); + + this.resources = new CloseableGroup(); + // The group holds one reader per file plus the merge. Avoid leaking resources when close() + // failure on one resource is called. + resources.setSuppressCloseFailure(true); + List<FileScanTask> tasks = Lists.newArrayList(taskGroup.tasks()); + this.fileReaders = + tasks.stream() + .map( + task -> + new RowDataReader( + table, + io, + new BaseScanTaskGroup<>(ImmutableList.of(task)), + mergeReadSchema, + caseSensitive, + cacheDeleteFilesOnExecutors)) + .toList(); + fileReaders.forEach(resources::addCloseable); + // Wrap each reader as a CloseableIterable and feed into SortedMerge. + List<CloseableIterable<TaggedRow>> fileIterables = Lists.newArrayListWithCapacity(tasks.size()); + for (int i = 0; i < tasks.size(); i++) { + fileIterables.add(readerToIterable(fileReaders.get(i), tasks.get(i))); + } + Comparator<InternalRow> rowComparator = buildComparator(mergeReadSchema, sortOrder); + SortedMerge<TaggedRow> sortedMerge = + new SortedMerge<>((a, b) -> rowComparator.compare(a.row(), b.row()), fileIterables); + resources.addCloseable(sortedMerge); + boolean threw = true; + try { + this.mergedIterator = sortedMerge.iterator(); + threw = false; + } finally { + if (threw) { + Exceptions.close(resources, true); + } + } + } + + /** + * Adapts a {@link RowDataReader} to a {@link CloseableIterable} for use with {@link SortedMerge}. + * + * <p>Rows are deep-copied on the way into the heap. {@link SortedMerge} advances an iterator + * before returning the value it just polled, so an uncopied row would be overwritten by the next + * read from the same file since Spark's Parquet and ORC readers reuse {@link InternalRow} + * containers. Plain {@link InternalRow#copy()} is not enough here: for columns holding an array + * or map of structs, the reader reuses the same mutable struct instance for every element, so + * {@code copy()} only clones the outer container and still shares the element with the reused + * buffer. {@link #deepCopyProjection} flattens the row into a self-contained {@code UnsafeRow}, + * fully detaching every nested element. At most one row per file is held at a time, so the cost + * is bounded by the number of files. + */ + private CloseableIterable<TaggedRow> readerToIterable(RowDataReader reader, FileScanTask task) { + FileBlock block = new FileBlock(task.file().location(), task.start(), task.length()); + return CloseableIterable.withNoopClose( Review Comment: I added `TaggedRowIterable` and `TaggedRowIterator` to iterate over the rows. ########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/source/MergingSortedRowDataReader.java: ########## @@ -0,0 +1,358 @@ +/* + * 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.io.IOException; +import java.io.UncheckedIOException; +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Objects; +import org.apache.iceberg.Accessor; +import org.apache.iceberg.Accessors; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortField; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.SortOrderComparators; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.Table; +import org.apache.iceberg.io.CloseableGroup; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.CloseableIterator; +import org.apache.iceberg.io.FileIO; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.SparkSchemaUtil; +import org.apache.iceberg.spark.source.metrics.TaskNumDeletes; +import org.apache.iceberg.spark.source.metrics.TaskNumSplits; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.TypeUtil; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Exceptions; +import org.apache.iceberg.util.SortedMerge; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.apache.spark.sql.catalyst.ProjectingInternalRow; +import org.apache.spark.sql.catalyst.expressions.UnsafeProjection; +import org.apache.spark.sql.connector.metric.CustomTaskMetric; +import org.apache.spark.sql.connector.read.PartitionReader; +import org.apache.spark.sql.types.StructType; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import scala.collection.JavaConverters; + +/** + * A {@link PartitionReader} that reads multiple sorted files and merges them into a single sorted + * stream using a k-way heap merge ({@link SortedMerge}). + * + * <p>Every file in the task group must be written with the table's current sort order. Sort keys on + * nested fields are not supported. + */ +class MergingSortedRowDataReader implements PartitionReader<InternalRow> { + private static final Logger LOG = LoggerFactory.getLogger(MergingSortedRowDataReader.class); + + private final CloseableGroup resources; + private final CloseableIterator<TaggedRow> mergedIterator; + private final List<RowDataReader> fileReaders; + // non-null only when sort key columns were added to the read schema beyond what Spark projected + private final ProjectingInternalRow projectingRow; + private final UnsafeProjection deepCopyProjection; + private InternalRow current; + private FileBlock currentBlock; + + MergingSortedRowDataReader(SparkInputPartition partition) { + this( + partition.table(), + partition.io(), + partition.taskGroup(), + partition.projection(), + partition.isCaseSensitive(), + partition.cacheDeleteFilesOnExecutors()); + } + + MergingSortedRowDataReader( + Table table, + FileIO io, + ScanTaskGroup<FileScanTask> taskGroup, + Schema projection, + boolean caseSensitive, + boolean cacheDeleteFilesOnExecutors) { + SortOrder sortOrder = table.sortOrder(); + int numFiles = taskGroup.tasks().size(); + + Preconditions.checkArgument( + sortOrder.isSorted(), "Cannot create merging reader for unsorted table %s", table.name()); + Preconditions.checkArgument( + numFiles > 1, "Merging reader requires multiple files, got %s", numFiles); + + int expectedOrderId = sortOrder.orderId(); + Preconditions.checkArgument( + taskGroup.tasks().stream() + .allMatch(task -> Objects.equals(task.file().sortOrderId(), expectedOrderId)), + "Not all files in task group have the expected sort order %s", + expectedOrderId); + + LOG.debug( + "Creating merging reader for {} files with sort order {} in table {}", + numFiles, + sortOrder.orderId(), + table.name()); + + // Augment the projected schema with any sort key columns Spark did not request so that + // SortOrderComparators can access every sort key field during the merge. + Schema mergeReadSchema = mergeReadSchema(projection, sortOrder, table); + this.projectingRow = buildProjectingRow(projection, mergeReadSchema); + this.deepCopyProjection = UnsafeProjection.create(SparkSchemaUtil.convert(mergeReadSchema)); + + this.resources = new CloseableGroup(); + // The group holds one reader per file plus the merge. Avoid leaking resources when close() + // failure on one resource is called. + resources.setSuppressCloseFailure(true); + List<FileScanTask> tasks = Lists.newArrayList(taskGroup.tasks()); + this.fileReaders = + tasks.stream() + .map( + task -> + new RowDataReader( + table, + io, + new BaseScanTaskGroup<>(ImmutableList.of(task)), + mergeReadSchema, + caseSensitive, + cacheDeleteFilesOnExecutors)) + .toList(); + fileReaders.forEach(resources::addCloseable); + // Wrap each reader as a CloseableIterable and feed into SortedMerge. + List<CloseableIterable<TaggedRow>> fileIterables = Lists.newArrayListWithCapacity(tasks.size()); + for (int i = 0; i < tasks.size(); i++) { + fileIterables.add(readerToIterable(fileReaders.get(i), tasks.get(i))); + } + Comparator<InternalRow> rowComparator = buildComparator(mergeReadSchema, sortOrder); + SortedMerge<TaggedRow> sortedMerge = + new SortedMerge<>((a, b) -> rowComparator.compare(a.row(), b.row()), fileIterables); + resources.addCloseable(sortedMerge); + boolean threw = true; + try { + this.mergedIterator = sortedMerge.iterator(); + threw = false; + } finally { + if (threw) { + Exceptions.close(resources, true); + } + } + } + + /** + * Adapts a {@link RowDataReader} to a {@link CloseableIterable} for use with {@link SortedMerge}. + * + * <p>Rows are deep-copied on the way into the heap. {@link SortedMerge} advances an iterator + * before returning the value it just polled, so an uncopied row would be overwritten by the next + * read from the same file since Spark's Parquet and ORC readers reuse {@link InternalRow} + * containers. Plain {@link InternalRow#copy()} is not enough here: for columns holding an array + * or map of structs, the reader reuses the same mutable struct instance for every element, so + * {@code copy()} only clones the outer container and still shares the element with the reused + * buffer. {@link #deepCopyProjection} flattens the row into a self-contained {@code UnsafeRow}, + * fully detaching every nested element. At most one row per file is held at a time, so the cost + * is bounded by the number of files. + */ + private CloseableIterable<TaggedRow> readerToIterable(RowDataReader reader, FileScanTask task) { + FileBlock block = new FileBlock(task.file().location(), task.start(), task.length()); + return CloseableIterable.withNoopClose( + () -> + new CloseableIterator<>() { + private boolean advanced = false; + private boolean hasNext = false; + + @Override + public boolean hasNext() { + if (!advanced) { + try { + hasNext = reader.next(); + advanced = true; + } catch (IOException e) { + throw new UncheckedIOException("Failed to advance reader", e); + } + } + return hasNext; + } + + @Override + public TaggedRow next() { + if (!advanced) { + hasNext(); + } + advanced = false; + InternalRow deepCopy = deepCopyProjection.apply(reader.get()).copy(); + return new TaggedRow(deepCopy, block); + } + + @Override + public void close() { + // Readers are owned by the enclosing CloseableGroup, not by the merge. SortedMerge + // drops iterators that are empty on the first hasNext() without closing them, so a + // file whose rows are all deleted would otherwise leak. Closing here too would + // double-close every reader the merge does drain. + } + }); + } + + @Override + public boolean next() throws IOException { + if (!mergedIterator.hasNext()) { + return false; + } + + TaggedRow tagged = mergedIterator.next(); + // all rows from one task share a FileBlock instance, so identity is enough to detect a switch + // and avoid re-allocating the block holder entry on every row + if (tagged.block() != currentBlock) { + FileBlock block = tagged.block(); + InputFileBlockHolder.set(block.filePath(), block.start(), block.length()); + this.currentBlock = block; + } + + InternalRow merged = tagged.row(); + if (projectingRow == null) { + this.current = merged; + } else { + projectingRow.project(merged); + this.current = projectingRow; + } + + return true; + } + + @Override + public InternalRow get() { + return current; + } + + @Override + public void close() throws IOException { + resources.close(); + } + + @Override + public CustomTaskMetric[] currentMetricsValues() { + long totalDeletes = + fileReaders.stream() + .flatMap(reader -> Arrays.stream(reader.currentMetricsValues())) + .filter(metric -> metric instanceof TaskNumDeletes) + .mapToLong(CustomTaskMetric::value) + .sum(); + return new CustomTaskMetric[] { + new TaskNumSplits(fileReaders.size()), new TaskNumDeletes(totalDeletes) + }; + } + + /** + * Builds a comparator for merging {@link InternalRow}s by the given sort order. Each side wraps + * its row in its own reusable {@link InternalRowWrapper} so the two arguments stay distinct. + */ + private static Comparator<InternalRow> buildComparator( + Schema mergeReadSchema, SortOrder sortOrder) { + StructType sparkSchema = SparkSchemaUtil.convert(mergeReadSchema); + Comparator<StructLike> keyComparator = + SortOrderComparators.forSchema(mergeReadSchema, sortOrder); + InternalRowWrapper left = new InternalRowWrapper(sparkSchema, mergeReadSchema.asStruct()); + InternalRowWrapper right = new InternalRowWrapper(sparkSchema, mergeReadSchema.asStruct()); + return (r1, r2) -> keyComparator.compare(left.wrap(r1), right.wrap(r2)); + } + + /** + * Returns a {@link ProjectingInternalRow} that remaps columns from the wider merge schema back to + * the requested projection, or {@code null} if no extra columns were added. + */ + private static ProjectingInternalRow buildProjectingRow(Schema projection, Schema mergeSchema) { + if (projection.sameSchema(mergeSchema)) { + return null; + } + + List<Object> positions = Lists.newArrayListWithCapacity(projection.columns().size()); + for (Types.NestedField column : projection.columns()) { + Accessor<StructLike> accessor = mergeSchema.accessorForField(column.fieldId()); + Preconditions.checkArgument( + accessor != null, + "Cannot find projected field id %s in merge read schema", + column.fieldId()); + positions.add(Accessors.toPosition(accessor)); + } + + StructType sparkSchema = SparkSchemaUtil.convert(projection); + return new ProjectingInternalRow(sparkSchema, JavaConverters.asScala(positions).toIndexedSeq()); + } + + /** + * Returns the schema to use when reading each file. This is the requested {@code projection} + * augmented with any sort key columns that are not already present, so the merge comparator can + * access every sort key field regardless of what Spark projected. + */ + private static Schema mergeReadSchema(Schema projection, SortOrder sortOrder, Table table) { Review Comment: I only found these - TypeUtil.select(schema, ids) and TypeUtil.project(schema, ids) pick fields by id but return them in the source schema's order. - TypeUtil.selectInIdOrder(schema, ids) returns them in field-id order. - Schema.select(names) does the same by name, in schema order. I agree we can move the UUID check outside since it's not related to merge schema so I created a `validateSortKeys()` utility. ########## spark/v4.1/spark/src/test/java/org/apache/iceberg/spark/source/TestMergingSortedRowDataReader.java: ########## @@ -0,0 +1,802 @@ +/* + * 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 static org.apache.iceberg.types.Types.NestedField.required; +import static org.assertj.core.api.Assertions.assertThat; +import static org.assertj.core.api.Assertions.assertThatThrownBy; +import static org.mockito.Mockito.doReturn; +import static org.mockito.Mockito.when; + +import java.io.File; +import java.io.IOException; +import java.nio.file.Path; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.UUID; +import java.util.function.Function; +import java.util.stream.Stream; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.Files; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableUtil; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.data.FileHelpers; +import org.apache.iceberg.data.GenericRecord; +import org.apache.iceberg.data.Record; +import org.apache.iceberg.expressions.Expressions; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.TestBase; +import org.apache.iceberg.transforms.Transform; +import org.apache.iceberg.transforms.Transforms; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Pair; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.io.TempDir; +import org.mockito.Mockito; + +class TestMergingSortedRowDataReader extends TestBase { + + private static final Schema SCHEMA = + new Schema( + required(1, "id", Types.IntegerType.get()), required(2, "data", Types.StringType.get())); + + private static final PartitionSpec SPEC = PartitionSpec.unpartitioned(); + + private Table table; + + @TempDir private Path temp; + + @BeforeEach + void before() { + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + table.replaceSortOrder().asc("id").commit(); + } + + @AfterEach + void after() { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + } + + @Test + void mergeTwoSortedFiles() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c"), record(5, "e")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d"), record(6, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 2, 3, 4, 5, 6); + } + + @Test + void mergeWithDuplicateKeys() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(2, "b")); + DataFile file2 = writeDataFile(record(1, "c"), record(2, "d")); + DataFile file3 = writeDataFile(record(1, "e"), record(3, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).appendFile(file3).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 1, 1, 2, 2, 3); + } + + @Test + void mergeDescendingOrder() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + table.replaceSortOrder().desc("id").commit(); + + DataFile file1 = writeDataFile(record(6, "f"), record(4, "d")); + DataFile file2 = writeDataFile(record(5, "e"), record(3, "c"), record(1, "a")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(6, 5, 4, 3, 1); + } + + @Test + void mergeWithNulls() throws IOException { + Schema nullableSchema = + new Schema( + Types.NestedField.optional(1, "id", Types.IntegerType.get()), + required(2, "data", Types.StringType.get())); + + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + table = + catalog.createTable( + TableIdentifier.of("default", "test_merging_reader"), nullableSchema, SPEC); + table.replaceSortOrder().asc("id").commit(); + + DataFile file1 = writeDataFile(nullRecord("x"), record(3, "c")); + DataFile file2 = writeDataFile(nullRecord("y"), record(1, "a"), record(2, "b")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(rows).hasSize(5); Review Comment: I changed to `assertThat(extractIds(rows)).containsExactly(null, null, 1, 2, 3);` ########## spark/v4.1/spark/src/test/java/org/apache/iceberg/spark/source/TestMergingSortedRowDataReader.java: ########## @@ -0,0 +1,802 @@ +/* + * 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 static org.apache.iceberg.types.Types.NestedField.required; +import static org.assertj.core.api.Assertions.assertThat; +import static org.assertj.core.api.Assertions.assertThatThrownBy; +import static org.mockito.Mockito.doReturn; +import static org.mockito.Mockito.when; + +import java.io.File; +import java.io.IOException; +import java.nio.file.Path; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.UUID; +import java.util.function.Function; +import java.util.stream.Stream; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.Files; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableUtil; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.data.FileHelpers; +import org.apache.iceberg.data.GenericRecord; +import org.apache.iceberg.data.Record; +import org.apache.iceberg.expressions.Expressions; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.TestBase; +import org.apache.iceberg.transforms.Transform; +import org.apache.iceberg.transforms.Transforms; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Pair; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.io.TempDir; +import org.mockito.Mockito; + +class TestMergingSortedRowDataReader extends TestBase { + + private static final Schema SCHEMA = + new Schema( + required(1, "id", Types.IntegerType.get()), required(2, "data", Types.StringType.get())); + + private static final PartitionSpec SPEC = PartitionSpec.unpartitioned(); + + private Table table; + + @TempDir private Path temp; + + @BeforeEach + void before() { + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + table.replaceSortOrder().asc("id").commit(); + } + + @AfterEach + void after() { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + } + + @Test + void mergeTwoSortedFiles() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(3, "c"), record(5, "e")); + DataFile file2 = writeDataFile(record(2, "b"), record(4, "d"), record(6, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 2, 3, 4, 5, 6); + } + + @Test + void mergeWithDuplicateKeys() throws IOException { + DataFile file1 = writeDataFile(record(1, "a"), record(2, "b")); + DataFile file2 = writeDataFile(record(1, "c"), record(2, "d")); + DataFile file3 = writeDataFile(record(1, "e"), record(3, "f")); + + table.newAppend().appendFile(file1).appendFile(file2).appendFile(file3).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(1, 1, 1, 2, 2, 3); + } + + @Test + void mergeDescendingOrder() throws IOException { + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); + table.replaceSortOrder().desc("id").commit(); + + DataFile file1 = writeDataFile(record(6, "f"), record(4, "d")); + DataFile file2 = writeDataFile(record(5, "e"), record(3, "c"), record(1, "a")); + + table.newAppend().appendFile(file1).appendFile(file2).commit(); + + List<InternalRow> rows = readMerged(table); + + assertThat(extractIds(rows)).containsExactly(6, 5, 4, 3, 1); + } + + @Test + void mergeWithNulls() throws IOException { + Schema nullableSchema = + new Schema( + Types.NestedField.optional(1, "id", Types.IntegerType.get()), + required(2, "data", Types.StringType.get())); + + catalog.dropTable(TableIdentifier.of("default", "test_merging_reader")); Review Comment: I changed to use one table and evolve schema for the tests. ########## spark/v4.1/spark/src/test/java/org/apache/iceberg/spark/source/TestMergingSortedRowDataReader.java: ########## @@ -0,0 +1,802 @@ +/* + * 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 static org.apache.iceberg.types.Types.NestedField.required; +import static org.assertj.core.api.Assertions.assertThat; +import static org.assertj.core.api.Assertions.assertThatThrownBy; +import static org.mockito.Mockito.doReturn; +import static org.mockito.Mockito.when; + +import java.io.File; +import java.io.IOException; +import java.nio.file.Path; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.UUID; +import java.util.function.Function; +import java.util.stream.Stream; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.Files; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.Table; +import org.apache.iceberg.TableUtil; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.data.FileHelpers; +import org.apache.iceberg.data.GenericRecord; +import org.apache.iceberg.data.Record; +import org.apache.iceberg.expressions.Expressions; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.TestBase; +import org.apache.iceberg.transforms.Transform; +import org.apache.iceberg.transforms.Transforms; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Pair; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.api.io.TempDir; +import org.mockito.Mockito; + +class TestMergingSortedRowDataReader extends TestBase { + + private static final Schema SCHEMA = + new Schema( + required(1, "id", Types.IntegerType.get()), required(2, "data", Types.StringType.get())); + + private static final PartitionSpec SPEC = PartitionSpec.unpartitioned(); + + private Table table; + + @TempDir private Path temp; + + @BeforeEach + void before() { + table = catalog.createTable(TableIdentifier.of("default", "test_merging_reader"), SCHEMA, SPEC); Review Comment: Done ########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/source/MergingSortedRowDataReader.java: ########## @@ -0,0 +1,358 @@ +/* + * 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.io.IOException; +import java.io.UncheckedIOException; +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Objects; +import org.apache.iceberg.Accessor; +import org.apache.iceberg.Accessors; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortField; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.SortOrderComparators; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.Table; +import org.apache.iceberg.io.CloseableGroup; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.CloseableIterator; +import org.apache.iceberg.io.FileIO; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.SparkSchemaUtil; +import org.apache.iceberg.spark.source.metrics.TaskNumDeletes; +import org.apache.iceberg.spark.source.metrics.TaskNumSplits; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.TypeUtil; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Exceptions; +import org.apache.iceberg.util.SortedMerge; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.apache.spark.sql.catalyst.ProjectingInternalRow; +import org.apache.spark.sql.catalyst.expressions.UnsafeProjection; +import org.apache.spark.sql.connector.metric.CustomTaskMetric; +import org.apache.spark.sql.connector.read.PartitionReader; +import org.apache.spark.sql.types.StructType; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import scala.collection.JavaConverters; + +/** + * A {@link PartitionReader} that reads multiple sorted files and merges them into a single sorted + * stream using a k-way heap merge ({@link SortedMerge}). + * + * <p>Every file in the task group must be written with the table's current sort order. Sort keys on + * nested fields are not supported. + */ +class MergingSortedRowDataReader implements PartitionReader<InternalRow> { + private static final Logger LOG = LoggerFactory.getLogger(MergingSortedRowDataReader.class); + + private final CloseableGroup resources; + private final CloseableIterator<TaggedRow> mergedIterator; + private final List<RowDataReader> fileReaders; + // non-null only when sort key columns were added to the read schema beyond what Spark projected + private final ProjectingInternalRow projectingRow; + private final UnsafeProjection deepCopyProjection; + private InternalRow current; + private FileBlock currentBlock; + + MergingSortedRowDataReader(SparkInputPartition partition) { + this( + partition.table(), + partition.io(), + partition.taskGroup(), + partition.projection(), + partition.isCaseSensitive(), + partition.cacheDeleteFilesOnExecutors()); + } + + MergingSortedRowDataReader( + Table table, + FileIO io, + ScanTaskGroup<FileScanTask> taskGroup, + Schema projection, + boolean caseSensitive, + boolean cacheDeleteFilesOnExecutors) { + SortOrder sortOrder = table.sortOrder(); + int numFiles = taskGroup.tasks().size(); + + Preconditions.checkArgument( + sortOrder.isSorted(), "Cannot create merging reader for unsorted table %s", table.name()); + Preconditions.checkArgument( + numFiles > 1, "Merging reader requires multiple files, got %s", numFiles); + + int expectedOrderId = sortOrder.orderId(); + Preconditions.checkArgument( + taskGroup.tasks().stream() + .allMatch(task -> Objects.equals(task.file().sortOrderId(), expectedOrderId)), + "Not all files in task group have the expected sort order %s", + expectedOrderId); Review Comment: I did not fully understand this. Even if the planner puts splits of the same files as tasks here, the algorithm will still work. Did you mean something else? ########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/source/MergingSortedRowDataReader.java: ########## @@ -0,0 +1,358 @@ +/* + * 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.io.IOException; +import java.io.UncheckedIOException; +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Objects; +import org.apache.iceberg.Accessor; +import org.apache.iceberg.Accessors; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortField; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.SortOrderComparators; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.Table; +import org.apache.iceberg.io.CloseableGroup; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.CloseableIterator; +import org.apache.iceberg.io.FileIO; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.SparkSchemaUtil; +import org.apache.iceberg.spark.source.metrics.TaskNumDeletes; +import org.apache.iceberg.spark.source.metrics.TaskNumSplits; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.TypeUtil; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Exceptions; +import org.apache.iceberg.util.SortedMerge; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.apache.spark.sql.catalyst.ProjectingInternalRow; +import org.apache.spark.sql.catalyst.expressions.UnsafeProjection; +import org.apache.spark.sql.connector.metric.CustomTaskMetric; +import org.apache.spark.sql.connector.read.PartitionReader; +import org.apache.spark.sql.types.StructType; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import scala.collection.JavaConverters; + +/** + * A {@link PartitionReader} that reads multiple sorted files and merges them into a single sorted + * stream using a k-way heap merge ({@link SortedMerge}). + * + * <p>Every file in the task group must be written with the table's current sort order. Sort keys on + * nested fields are not supported. + */ +class MergingSortedRowDataReader implements PartitionReader<InternalRow> { + private static final Logger LOG = LoggerFactory.getLogger(MergingSortedRowDataReader.class); + + private final CloseableGroup resources; + private final CloseableIterator<TaggedRow> mergedIterator; + private final List<RowDataReader> fileReaders; + // non-null only when sort key columns were added to the read schema beyond what Spark projected + private final ProjectingInternalRow projectingRow; + private final UnsafeProjection deepCopyProjection; + private InternalRow current; + private FileBlock currentBlock; + + MergingSortedRowDataReader(SparkInputPartition partition) { + this( + partition.table(), + partition.io(), + partition.taskGroup(), + partition.projection(), + partition.isCaseSensitive(), + partition.cacheDeleteFilesOnExecutors()); + } + + MergingSortedRowDataReader( + Table table, + FileIO io, + ScanTaskGroup<FileScanTask> taskGroup, + Schema projection, + boolean caseSensitive, + boolean cacheDeleteFilesOnExecutors) { + SortOrder sortOrder = table.sortOrder(); Review Comment: Done. ########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/source/MergingSortedRowDataReader.java: ########## @@ -0,0 +1,358 @@ +/* + * 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.io.IOException; +import java.io.UncheckedIOException; +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Objects; +import org.apache.iceberg.Accessor; +import org.apache.iceberg.Accessors; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortField; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.SortOrderComparators; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.Table; +import org.apache.iceberg.io.CloseableGroup; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.CloseableIterator; +import org.apache.iceberg.io.FileIO; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.SparkSchemaUtil; +import org.apache.iceberg.spark.source.metrics.TaskNumDeletes; +import org.apache.iceberg.spark.source.metrics.TaskNumSplits; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.TypeUtil; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Exceptions; +import org.apache.iceberg.util.SortedMerge; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.apache.spark.sql.catalyst.ProjectingInternalRow; +import org.apache.spark.sql.catalyst.expressions.UnsafeProjection; +import org.apache.spark.sql.connector.metric.CustomTaskMetric; +import org.apache.spark.sql.connector.read.PartitionReader; +import org.apache.spark.sql.types.StructType; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import scala.collection.JavaConverters; + +/** + * A {@link PartitionReader} that reads multiple sorted files and merges them into a single sorted + * stream using a k-way heap merge ({@link SortedMerge}). + * + * <p>Every file in the task group must be written with the table's current sort order. Sort keys on + * nested fields are not supported. + */ +class MergingSortedRowDataReader implements PartitionReader<InternalRow> { + private static final Logger LOG = LoggerFactory.getLogger(MergingSortedRowDataReader.class); + + private final CloseableGroup resources; + private final CloseableIterator<TaggedRow> mergedIterator; + private final List<RowDataReader> fileReaders; + // non-null only when sort key columns were added to the read schema beyond what Spark projected + private final ProjectingInternalRow projectingRow; + private final UnsafeProjection deepCopyProjection; + private InternalRow current; + private FileBlock currentBlock; + + MergingSortedRowDataReader(SparkInputPartition partition) { + this( + partition.table(), + partition.io(), + partition.taskGroup(), + partition.projection(), + partition.isCaseSensitive(), + partition.cacheDeleteFilesOnExecutors()); + } + + MergingSortedRowDataReader( + Table table, + FileIO io, + ScanTaskGroup<FileScanTask> taskGroup, + Schema projection, + boolean caseSensitive, + boolean cacheDeleteFilesOnExecutors) { + SortOrder sortOrder = table.sortOrder(); + int numFiles = taskGroup.tasks().size(); + + Preconditions.checkArgument( + sortOrder.isSorted(), "Cannot create merging reader for unsorted table %s", table.name()); + Preconditions.checkArgument( + numFiles > 1, "Merging reader requires multiple files, got %s", numFiles); + + int expectedOrderId = sortOrder.orderId(); + Preconditions.checkArgument( + taskGroup.tasks().stream() + .allMatch(task -> Objects.equals(task.file().sortOrderId(), expectedOrderId)), + "Not all files in task group have the expected sort order %s", + expectedOrderId); + + LOG.debug( + "Creating merging reader for {} files with sort order {} in table {}", + numFiles, + sortOrder.orderId(), + table.name()); + + // Augment the projected schema with any sort key columns Spark did not request so that + // SortOrderComparators can access every sort key field during the merge. + Schema mergeReadSchema = mergeReadSchema(projection, sortOrder, table); + this.projectingRow = buildProjectingRow(projection, mergeReadSchema); + this.deepCopyProjection = UnsafeProjection.create(SparkSchemaUtil.convert(mergeReadSchema)); + + this.resources = new CloseableGroup(); + // The group holds one reader per file plus the merge. Avoid leaking resources when close() + // failure on one resource is called. + resources.setSuppressCloseFailure(true); + List<FileScanTask> tasks = Lists.newArrayList(taskGroup.tasks()); + this.fileReaders = + tasks.stream() + .map( + task -> + new RowDataReader( + table, + io, + new BaseScanTaskGroup<>(ImmutableList.of(task)), + mergeReadSchema, + caseSensitive, + cacheDeleteFilesOnExecutors)) + .toList(); + fileReaders.forEach(resources::addCloseable); + // Wrap each reader as a CloseableIterable and feed into SortedMerge. + List<CloseableIterable<TaggedRow>> fileIterables = Lists.newArrayListWithCapacity(tasks.size()); + for (int i = 0; i < tasks.size(); i++) { + fileIterables.add(readerToIterable(fileReaders.get(i), tasks.get(i))); + } + Comparator<InternalRow> rowComparator = buildComparator(mergeReadSchema, sortOrder); + SortedMerge<TaggedRow> sortedMerge = + new SortedMerge<>((a, b) -> rowComparator.compare(a.row(), b.row()), fileIterables); + resources.addCloseable(sortedMerge); + boolean threw = true; + try { + this.mergedIterator = sortedMerge.iterator(); + threw = false; + } finally { + if (threw) { + Exceptions.close(resources, true); + } + } + } + + /** + * Adapts a {@link RowDataReader} to a {@link CloseableIterable} for use with {@link SortedMerge}. + * + * <p>Rows are deep-copied on the way into the heap. {@link SortedMerge} advances an iterator + * before returning the value it just polled, so an uncopied row would be overwritten by the next + * read from the same file since Spark's Parquet and ORC readers reuse {@link InternalRow} + * containers. Plain {@link InternalRow#copy()} is not enough here: for columns holding an array + * or map of structs, the reader reuses the same mutable struct instance for every element, so + * {@code copy()} only clones the outer container and still shares the element with the reused + * buffer. {@link #deepCopyProjection} flattens the row into a self-contained {@code UnsafeRow}, + * fully detaching every nested element. At most one row per file is held at a time, so the cost + * is bounded by the number of files. + */ + private CloseableIterable<TaggedRow> readerToIterable(RowDataReader reader, FileScanTask task) { + FileBlock block = new FileBlock(task.file().location(), task.start(), task.length()); + return CloseableIterable.withNoopClose( + () -> + new CloseableIterator<>() { + private boolean advanced = false; + private boolean hasNext = false; + + @Override + public boolean hasNext() { + if (!advanced) { + try { + hasNext = reader.next(); + advanced = true; + } catch (IOException e) { + throw new UncheckedIOException("Failed to advance reader", e); + } + } + return hasNext; + } + + @Override + public TaggedRow next() { + if (!advanced) { + hasNext(); + } + advanced = false; + InternalRow deepCopy = deepCopyProjection.apply(reader.get()).copy(); + return new TaggedRow(deepCopy, block); + } + + @Override + public void close() { + // Readers are owned by the enclosing CloseableGroup, not by the merge. SortedMerge + // drops iterators that are empty on the first hasNext() without closing them, so a + // file whose rows are all deleted would otherwise leak. Closing here too would + // double-close every reader the merge does drain. + } + }); + } + + @Override + public boolean next() throws IOException { + if (!mergedIterator.hasNext()) { + return false; + } + + TaggedRow tagged = mergedIterator.next(); + // all rows from one task share a FileBlock instance, so identity is enough to detect a switch + // and avoid re-allocating the block holder entry on every row + if (tagged.block() != currentBlock) { + FileBlock block = tagged.block(); + InputFileBlockHolder.set(block.filePath(), block.start(), block.length()); + this.currentBlock = block; + } + + InternalRow merged = tagged.row(); + if (projectingRow == null) { + this.current = merged; + } else { + projectingRow.project(merged); + this.current = projectingRow; + } + + return true; + } + + @Override + public InternalRow get() { + return current; + } + + @Override + public void close() throws IOException { + resources.close(); + } + + @Override + public CustomTaskMetric[] currentMetricsValues() { + long totalDeletes = + fileReaders.stream() + .flatMap(reader -> Arrays.stream(reader.currentMetricsValues())) + .filter(metric -> metric instanceof TaskNumDeletes) + .mapToLong(CustomTaskMetric::value) + .sum(); + return new CustomTaskMetric[] { + new TaskNumSplits(fileReaders.size()), new TaskNumDeletes(totalDeletes) + }; + } + + /** + * Builds a comparator for merging {@link InternalRow}s by the given sort order. Each side wraps + * its row in its own reusable {@link InternalRowWrapper} so the two arguments stay distinct. + */ + private static Comparator<InternalRow> buildComparator( + Schema mergeReadSchema, SortOrder sortOrder) { + StructType sparkSchema = SparkSchemaUtil.convert(mergeReadSchema); + Comparator<StructLike> keyComparator = + SortOrderComparators.forSchema(mergeReadSchema, sortOrder); + InternalRowWrapper left = new InternalRowWrapper(sparkSchema, mergeReadSchema.asStruct()); + InternalRowWrapper right = new InternalRowWrapper(sparkSchema, mergeReadSchema.asStruct()); + return (r1, r2) -> keyComparator.compare(left.wrap(r1), right.wrap(r2)); + } + + /** + * Returns a {@link ProjectingInternalRow} that remaps columns from the wider merge schema back to + * the requested projection, or {@code null} if no extra columns were added. + */ + private static ProjectingInternalRow buildProjectingRow(Schema projection, Schema mergeSchema) { + if (projection.sameSchema(mergeSchema)) { + return null; + } + + List<Object> positions = Lists.newArrayListWithCapacity(projection.columns().size()); Review Comment: I redid this to just use range of ordinals. Let me know what you think. ``` case class ProjectingInternalRow(schema: StructType, colOrdinals: IndexedSeq[Int]) ``` ########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/source/MergingSortedRowDataReader.java: ########## @@ -0,0 +1,358 @@ +/* + * 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.io.IOException; +import java.io.UncheckedIOException; +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Objects; +import org.apache.iceberg.Accessor; +import org.apache.iceberg.Accessors; +import org.apache.iceberg.BaseScanTaskGroup; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.ScanTaskGroup; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortField; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.SortOrderComparators; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.Table; +import org.apache.iceberg.io.CloseableGroup; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.CloseableIterator; +import org.apache.iceberg.io.FileIO; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.spark.SparkSchemaUtil; +import org.apache.iceberg.spark.source.metrics.TaskNumDeletes; +import org.apache.iceberg.spark.source.metrics.TaskNumSplits; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.TypeUtil; +import org.apache.iceberg.types.Types; +import org.apache.iceberg.util.Exceptions; +import org.apache.iceberg.util.SortedMerge; +import org.apache.spark.rdd.InputFileBlockHolder; +import org.apache.spark.sql.catalyst.InternalRow; +import org.apache.spark.sql.catalyst.ProjectingInternalRow; +import org.apache.spark.sql.catalyst.expressions.UnsafeProjection; +import org.apache.spark.sql.connector.metric.CustomTaskMetric; +import org.apache.spark.sql.connector.read.PartitionReader; +import org.apache.spark.sql.types.StructType; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import scala.collection.JavaConverters; + +/** + * A {@link PartitionReader} that reads multiple sorted files and merges them into a single sorted + * stream using a k-way heap merge ({@link SortedMerge}). + * + * <p>Every file in the task group must be written with the table's current sort order. Sort keys on + * nested fields are not supported. + */ +class MergingSortedRowDataReader implements PartitionReader<InternalRow> { + private static final Logger LOG = LoggerFactory.getLogger(MergingSortedRowDataReader.class); + + private final CloseableGroup resources; + private final CloseableIterator<TaggedRow> mergedIterator; + private final List<RowDataReader> fileReaders; + // non-null only when sort key columns were added to the read schema beyond what Spark projected + private final ProjectingInternalRow projectingRow; + private final UnsafeProjection deepCopyProjection; + private InternalRow current; + private FileBlock currentBlock; + + MergingSortedRowDataReader(SparkInputPartition partition) { + this( + partition.table(), + partition.io(), + partition.taskGroup(), + partition.projection(), + partition.isCaseSensitive(), + partition.cacheDeleteFilesOnExecutors()); + } + + MergingSortedRowDataReader( + Table table, + FileIO io, + ScanTaskGroup<FileScanTask> taskGroup, + Schema projection, + boolean caseSensitive, + boolean cacheDeleteFilesOnExecutors) { + SortOrder sortOrder = table.sortOrder(); + int numFiles = taskGroup.tasks().size(); + + Preconditions.checkArgument( + sortOrder.isSorted(), "Cannot create merging reader for unsorted table %s", table.name()); + Preconditions.checkArgument( + numFiles > 1, "Merging reader requires multiple files, got %s", numFiles); + + int expectedOrderId = sortOrder.orderId(); + Preconditions.checkArgument( + taskGroup.tasks().stream() + .allMatch(task -> Objects.equals(task.file().sortOrderId(), expectedOrderId)), + "Not all files in task group have the expected sort order %s", + expectedOrderId); + + LOG.debug( + "Creating merging reader for {} files with sort order {} in table {}", + numFiles, + sortOrder.orderId(), + table.name()); + + // Augment the projected schema with any sort key columns Spark did not request so that + // SortOrderComparators can access every sort key field during the merge. + Schema mergeReadSchema = mergeReadSchema(projection, sortOrder, table); + this.projectingRow = buildProjectingRow(projection, mergeReadSchema); + this.deepCopyProjection = UnsafeProjection.create(SparkSchemaUtil.convert(mergeReadSchema)); + + this.resources = new CloseableGroup(); + // The group holds one reader per file plus the merge. Avoid leaking resources when close() + // failure on one resource is called. + resources.setSuppressCloseFailure(true); + List<FileScanTask> tasks = Lists.newArrayList(taskGroup.tasks()); + this.fileReaders = + tasks.stream() + .map( + task -> + new RowDataReader( + table, + io, + new BaseScanTaskGroup<>(ImmutableList.of(task)), + mergeReadSchema, + caseSensitive, + cacheDeleteFilesOnExecutors)) + .toList(); + fileReaders.forEach(resources::addCloseable); + // Wrap each reader as a CloseableIterable and feed into SortedMerge. + List<CloseableIterable<TaggedRow>> fileIterables = Lists.newArrayListWithCapacity(tasks.size()); + for (int i = 0; i < tasks.size(); i++) { + fileIterables.add(readerToIterable(fileReaders.get(i), tasks.get(i))); + } + Comparator<InternalRow> rowComparator = buildComparator(mergeReadSchema, sortOrder); + SortedMerge<TaggedRow> sortedMerge = + new SortedMerge<>((a, b) -> rowComparator.compare(a.row(), b.row()), fileIterables); + resources.addCloseable(sortedMerge); + boolean threw = true; + try { + this.mergedIterator = sortedMerge.iterator(); + threw = false; + } finally { + if (threw) { + Exceptions.close(resources, true); + } + } + } + + /** + * Adapts a {@link RowDataReader} to a {@link CloseableIterable} for use with {@link SortedMerge}. + * + * <p>Rows are deep-copied on the way into the heap. {@link SortedMerge} advances an iterator + * before returning the value it just polled, so an uncopied row would be overwritten by the next + * read from the same file since Spark's Parquet and ORC readers reuse {@link InternalRow} + * containers. Plain {@link InternalRow#copy()} is not enough here: for columns holding an array + * or map of structs, the reader reuses the same mutable struct instance for every element, so + * {@code copy()} only clones the outer container and still shares the element with the reused + * buffer. {@link #deepCopyProjection} flattens the row into a self-contained {@code UnsafeRow}, + * fully detaching every nested element. At most one row per file is held at a time, so the cost + * is bounded by the number of files. + */ + private CloseableIterable<TaggedRow> readerToIterable(RowDataReader reader, FileScanTask task) { + FileBlock block = new FileBlock(task.file().location(), task.start(), task.length()); + return CloseableIterable.withNoopClose( + () -> + new CloseableIterator<>() { + private boolean advanced = false; + private boolean hasNext = false; + + @Override + public boolean hasNext() { + if (!advanced) { + try { + hasNext = reader.next(); + advanced = true; + } catch (IOException e) { + throw new UncheckedIOException("Failed to advance reader", e); + } + } + return hasNext; + } + + @Override + public TaggedRow next() { + if (!advanced) { + hasNext(); + } + advanced = false; + InternalRow deepCopy = deepCopyProjection.apply(reader.get()).copy(); + return new TaggedRow(deepCopy, block); + } + + @Override + public void close() { + // Readers are owned by the enclosing CloseableGroup, not by the merge. SortedMerge + // drops iterators that are empty on the first hasNext() without closing them, so a + // file whose rows are all deleted would otherwise leak. Closing here too would + // double-close every reader the merge does drain. + } + }); + } + + @Override + public boolean next() throws IOException { + if (!mergedIterator.hasNext()) { + return false; + } + + TaggedRow tagged = mergedIterator.next(); + // all rows from one task share a FileBlock instance, so identity is enough to detect a switch + // and avoid re-allocating the block holder entry on every row + if (tagged.block() != currentBlock) { + FileBlock block = tagged.block(); + InputFileBlockHolder.set(block.filePath(), block.start(), block.length()); + this.currentBlock = block; + } + + InternalRow merged = tagged.row(); + if (projectingRow == null) { + this.current = merged; + } else { + projectingRow.project(merged); + this.current = projectingRow; + } + + return true; + } + + @Override + public InternalRow get() { + return current; + } + + @Override + public void close() throws IOException { + resources.close(); + } + + @Override + public CustomTaskMetric[] currentMetricsValues() { + long totalDeletes = + fileReaders.stream() + .flatMap(reader -> Arrays.stream(reader.currentMetricsValues())) + .filter(metric -> metric instanceof TaskNumDeletes) + .mapToLong(CustomTaskMetric::value) + .sum(); + return new CustomTaskMetric[] { + new TaskNumSplits(fileReaders.size()), new TaskNumDeletes(totalDeletes) + }; + } + + /** + * Builds a comparator for merging {@link InternalRow}s by the given sort order. Each side wraps + * its row in its own reusable {@link InternalRowWrapper} so the two arguments stay distinct. + */ + private static Comparator<InternalRow> buildComparator( + Schema mergeReadSchema, SortOrder sortOrder) { + StructType sparkSchema = SparkSchemaUtil.convert(mergeReadSchema); + Comparator<StructLike> keyComparator = + SortOrderComparators.forSchema(mergeReadSchema, sortOrder); + InternalRowWrapper left = new InternalRowWrapper(sparkSchema, mergeReadSchema.asStruct()); + InternalRowWrapper right = new InternalRowWrapper(sparkSchema, mergeReadSchema.asStruct()); + return (r1, r2) -> keyComparator.compare(left.wrap(r1), right.wrap(r2)); + } + + /** + * Returns a {@link ProjectingInternalRow} that remaps columns from the wider merge schema back to + * the requested projection, or {@code null} if no extra columns were added. + */ + private static ProjectingInternalRow buildProjectingRow(Schema projection, Schema mergeSchema) { + if (projection.sameSchema(mergeSchema)) { + return null; Review Comment: I took this line out. 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