luoyuxia commented on code in PR #1543: URL: https://github.com/apache/fluss/pull/1543#discussion_r2281623053
########## fluss-flink/fluss-flink-common/src/main/java/com/alibaba/fluss/flink/lake/reader/LakeSnapshotAndLogSplitScanner.java: ########## @@ -0,0 +1,245 @@ +/* + * 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 com.alibaba.fluss.flink.lake.reader; + +import com.alibaba.fluss.client.table.Table; +import com.alibaba.fluss.client.table.scanner.ScanRecord; +import com.alibaba.fluss.client.table.scanner.batch.BatchScanner; +import com.alibaba.fluss.client.table.scanner.log.LogScanner; +import com.alibaba.fluss.client.table.scanner.log.ScanRecords; +import com.alibaba.fluss.flink.lake.split.LakeSnapshotAndFlussLogSplit; +import com.alibaba.fluss.lake.source.LakeSource; +import com.alibaba.fluss.lake.source.LakeSplit; +import com.alibaba.fluss.lake.source.RecordReader; +import com.alibaba.fluss.lake.source.SortedRecordReader; +import com.alibaba.fluss.metadata.TableBucket; +import com.alibaba.fluss.record.ChangeType; +import com.alibaba.fluss.record.LogRecord; +import com.alibaba.fluss.row.InternalRow; +import com.alibaba.fluss.utils.CloseableIterator; + +import javax.annotation.Nullable; + +import java.io.IOException; +import java.time.Duration; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collections; +import java.util.Comparator; +import java.util.List; +import java.util.SortedMap; +import java.util.TreeMap; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +/** A scanner to merge the lakehouse's snapshot and change log. */ +public class LakeSnapshotAndLogSplitScanner implements BatchScanner { + + private final LakeSnapshotAndFlussLogSplit lakeSnapshotSplitAndFlussLogSplit; + private Comparator<InternalRow> rowComparator; + private List<CloseableIterator<LogRecord>> lakeRecordIterators = new ArrayList<>(); + private final LakeSource<LakeSplit> lakeSource; + + private final int[] pkIndexes; + + // the indexes of primary key in emitted row by paimon and fluss + private int[] keyIndexesInRow; + @Nullable private int[] adjustProjectedFields; + private int[] newProjectedFields; + + // the sorted logs in memory, mapping from key -> value + private SortedMap<InternalRow, KeyValueRow> logRows; + + private final LogScanner logScanner; + private final long stoppingOffset; + private boolean logScanFinished; + + private SortMergeReader currentSortMergeReader; + + public LakeSnapshotAndLogSplitScanner( + Table table, + LakeSource<LakeSplit> lakeSource, + LakeSnapshotAndFlussLogSplit lakeSnapshotAndFlussLogSplit) { + this.pkIndexes = table.getTableInfo().getSchema().getPrimaryKeyIndexes(); + this.lakeSnapshotSplitAndFlussLogSplit = lakeSnapshotAndFlussLogSplit; + this.lakeSource = lakeSource; + this.newProjectedFields = getNeedProjectFields(table); + + this.logScanner = table.newScan().project(newProjectedFields).createLogScanner(); + this.lakeSource.withProject( + Arrays.stream(newProjectedFields) + .mapToObj(field -> new int[] {field}) + .toArray(int[][]::new)); + + TableBucket tableBucket = lakeSnapshotAndFlussLogSplit.getTableBucket(); + if (tableBucket.getPartitionId() != null) { + this.logScanner.subscribe( + tableBucket.getPartitionId(), + tableBucket.getBucket(), + lakeSnapshotAndFlussLogSplit.getStartingOffset()); + } else { + this.logScanner.subscribe( + tableBucket.getBucket(), lakeSnapshotAndFlussLogSplit.getStartingOffset()); + } + + this.stoppingOffset = + lakeSnapshotAndFlussLogSplit + .getStoppingOffset() + .orElseThrow( + () -> + new RuntimeException( + "StoppingOffset is null for split: " + + lakeSnapshotAndFlussLogSplit)); + + this.logScanFinished = lakeSnapshotAndFlussLogSplit.getStartingOffset() >= stoppingOffset; + } + + private int[] getNeedProjectFields(Table flussTable) { + if (lakeSource.getProject() != null) { + int[] projectedFields = + Arrays.stream(lakeSource.getProject()).mapToInt(field -> field[0]).toArray(); + // we need to include the primary key in projected fields to sort merge by pk + // if the provided don't include, we need to include it + List<Integer> newProjectedFields = + Arrays.stream(projectedFields).boxed().collect(Collectors.toList()); + + // the indexes of primary key with new projected fields + keyIndexesInRow = new int[pkIndexes.length]; + for (int i = 0; i < pkIndexes.length; i++) { + int primaryKeyIndex = pkIndexes[i]; + // search the pk in projected fields + int indexInProjectedFields = findIndex(projectedFields, primaryKeyIndex); + if (indexInProjectedFields >= 0) { + keyIndexesInRow[i] = indexInProjectedFields; + } else { + // no pk in projected fields, we must include it to do + // merge sort + newProjectedFields.add(primaryKeyIndex); + keyIndexesInRow[i] = newProjectedFields.size() - 1; + } + } + int[] newProjection = newProjectedFields.stream().mapToInt(Integer::intValue).toArray(); + // the underlying scan will use the new projection to scan data, + // but will still need to map from the new projection to the origin projected fields + int[] adjustProjectedFields = new int[projectedFields.length]; + for (int i = 0; i < projectedFields.length; i++) { + adjustProjectedFields[i] = findIndex(newProjection, projectedFields[i]); + } + this.adjustProjectedFields = adjustProjectedFields; + return newProjection; + } else { + // no projectedFields, use all fields + keyIndexesInRow = pkIndexes; + return IntStream.range(0, flussTable.getTableInfo().getRowType().getFieldCount()) + .toArray(); + } + } + + private int findIndex(int[] array, int target) { + int index = -1; + for (int i = 0; i < array.length; i++) { + if (array[i] == target) { + index = i; + break; + } + } + return index; + } + + @Nullable + @Override + public CloseableIterator<InternalRow> pollBatch(Duration timeout) throws IOException { + if (logScanFinished) { + if (lakeRecordIterators.isEmpty()) { + if (lakeSnapshotSplitAndFlussLogSplit.getLakeSplits() == null + || lakeSnapshotSplitAndFlussLogSplit.getLakeSplits().isEmpty()) { + lakeRecordIterators = + Collections.singletonList(CloseableIterator.emptyIterator()); + } + for (LakeSplit lakeSplit : lakeSnapshotSplitAndFlussLogSplit.getLakeSplits()) { + lakeRecordIterators.add(lakeSource.createRecordReader(() -> lakeSplit).read()); + } + } + if (currentSortMergeReader == null) { + currentSortMergeReader = + new SortMergeReader( + adjustProjectedFields, + keyIndexesInRow, + lakeRecordIterators, + rowComparator, + CloseableIterator.wrap( + logRows == null + ? Collections.emptyIterator() + : logRows.values().iterator())); + } + return currentSortMergeReader.readBatch(); + } else { + if (lakeRecordIterators.isEmpty()) { + if (lakeSnapshotSplitAndFlussLogSplit.getLakeSplits() == null + || lakeSnapshotSplitAndFlussLogSplit.getLakeSplits().isEmpty()) { + lakeRecordIterators = + Collections.singletonList(CloseableIterator.emptyIterator()); + } + for (LakeSplit lakeSplit : lakeSnapshotSplitAndFlussLogSplit.getLakeSplits()) { + RecordReader reader = lakeSource.createRecordReader(() -> lakeSplit); + if (reader instanceof SortedRecordReader) { + rowComparator = ((SortedRecordReader) reader).order(); + } else { + throw new UnsupportedOperationException( + "lake records must instance of sorted view."); + } + lakeRecordIterators.add(reader.read()); + } + logRows = new TreeMap<>(rowComparator); Review Comment: Please don't forget my this comment -- This is an automated message from the Apache Git Service. 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