gaborkaszab commented on code in PR #17541: URL: https://github.com/apache/iceberg/pull/17541#discussion_r3845659376
########## core/src/main/java/org/apache/iceberg/ScanTaskPlanner.java: ########## @@ -0,0 +1,314 @@ +/* + * 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; + +import java.io.IOException; +import java.io.UncheckedIOException; +import java.nio.ByteBuffer; +import java.util.List; +import java.util.Map; +import java.util.concurrent.ExecutorService; +import org.apache.iceberg.expressions.Expression; +import org.apache.iceberg.expressions.Expressions; +import org.apache.iceberg.expressions.ResidualEvaluator; +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.io.InputFile; +import org.apache.iceberg.metrics.ScanMetrics; +import org.apache.iceberg.metrics.ScanMetricsUtil; +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.ImmutableMap; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.util.ParallelIterable; + +/** + * Plans {@link FileScanTask}s from a V4 root manifest. + * + * <p>Emits a task for each live {@code DATA} entry and expands {@code DATA_MANIFEST} entries into + * their leaf manifests. A data entry's colocated deletion vector is attached to its task as a + * {@link DeleteFile}. + */ +class ScanTaskPlanner { + private static final DeleteFile[] NO_DELETES = new DeleteFile[0]; + + private final FileIO io; + private final String rootManifestLocation; + private final Map<Integer, PartitionSpec> specsById; + private final String tableLocation; + private final Expression dataFilter; + private final boolean ignoreResiduals; + private final boolean caseSensitive; + private final ScanMetrics scanMetrics; + private final ExecutorService executorService; + private final Map<Integer, TaskContext> taskContextsBySpec = Maps.newConcurrentMap(); + + private ScanTaskPlanner( + FileIO io, + String rootManifestLocation, + Map<Integer, PartitionSpec> specsById, + String tableLocation, + Expression dataFilter, + boolean ignoreResiduals, + boolean caseSensitive, + ScanMetrics scanMetrics, + ExecutorService executorService) { + this.io = io; + this.rootManifestLocation = rootManifestLocation; + this.specsById = specsById; + this.tableLocation = tableLocation; + this.dataFilter = dataFilter; + this.ignoreResiduals = ignoreResiduals; + this.caseSensitive = caseSensitive; + this.scanMetrics = scanMetrics; + this.executorService = executorService; + } + + static Builder builder( + FileIO io, + String rootManifestLocation, + Map<Integer, PartitionSpec> specsById, + String tableLocation) { + return new Builder(io, rootManifestLocation, specsById, tableLocation); + } + + CloseableIterable<FileScanTask> planFiles() { + List<TrackedFile> rootDataFiles = Lists.newArrayList(); + List<TrackedFile> leafManifests = Lists.newArrayList(); + + // root is drained into these lists. Leaf references must be buffered so they can be fanned + // out; direct DATA entries are buffered too, bounded by how many data files a tree keeps + // directly in the root. Leaf tasks stay lazy: planLeaf opens no reader until iterated. + scanMetrics.scannedDataManifests().increment(); + try (CloseableIterable<TrackedFile> rootEntries = + open(io.newInputFile(rootManifestLocation), /* manifestDv= */ null)) { + for (TrackedFile entry : rootEntries) { + switch (entry.contentType()) { + case DATA: + rootDataFiles.add(entry); + break; + case DATA_MANIFEST: + leafManifests.add(entry); + break; + default: + // delete manifests appear only on upgraded v2/v3 tables; that 2-phase path is not + // supported yet, so a natively-written v4 tree is the only supported input for now + throw new UnsupportedOperationException( + "Cannot plan content type in root manifest: " + entry.contentType()); + } + } + } catch (IOException e) { + throw new UncheckedIOException("Failed to close root manifest: " + rootManifestLocation, e); + } + + // read each leaf's data entries lazily; only leaf reads are worth the parallel backend, so the + // already-in-hand root data entries are concatenated in directly + List<CloseableIterable<TrackedFile>> leafDataEntries = Lists.newArrayList(); + for (TrackedFile leaf : leafManifests) { + leafDataEntries.add(planLeaf(leaf)); + } + + CloseableIterable<TrackedFile> expandedLeafEntries = Review Comment: If I'm not mistaken, this is able to read a 2-level metadata tree: root and leaves. I recall there was a discussion that theoretically we can have more levels in the tree. I'm not sure if there is anything in the proposed spec or anywhere that prevents writers doing that, but if not, I'm wondering we should be flexible enough on the read path to support such a layout. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
