rdblue commented on code in PR #6706: URL: https://github.com/apache/iceberg/pull/6706#discussion_r1098067598
########## core/src/main/java/org/apache/iceberg/SnapshotOperations.java: ########## @@ -0,0 +1,263 @@ +/* + * 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.Serializable; +import java.util.Collection; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.function.Function; +import java.util.stream.Collectors; +import org.apache.iceberg.exceptions.ValidationException; +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.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.relocated.com.google.common.collect.Sets; +import org.apache.iceberg.util.SerializableMap; +import org.apache.iceberg.util.SerializableSupplier; + +/** + * SnapshotOperations abstracts access to snapshots for table metadata. This allows a subset of + * snapshots/refs to be loaded initially for operations that do not require all to be present (e.g. + * table scans of the current snapshot). + * + * <p>In the event that snapshots/refs need to be accessed, the provided supplier will be invoked, + * which must provide all addressable snapshots for the table. + */ +class SnapshotOperations implements Serializable { + private List<Snapshot> snapshots; + private final SerializableSupplier<List<Snapshot>> snapshotsSupplier; + private Map<Long, Snapshot> snapshotsById; + private Map<String, SnapshotRef> refs; + private final SerializableSupplier<Map<String, SnapshotRef>> refsSupplier; + private boolean loaded; + + private SnapshotOperations( + List<Snapshot> snapshots, + SerializableSupplier<List<Snapshot>> snapshotsSupplier, + Map<String, SnapshotRef> refs, + SerializableSupplier<Map<String, SnapshotRef>> refsSupplier) { + this.snapshots = ImmutableList.copyOf(snapshots); + this.snapshotsSupplier = snapshotsSupplier; + this.refs = SerializableMap.copyOf(refs); + this.refsSupplier = refsSupplier; + + this.snapshotsById = indexSnapshotsById(snapshots); + } + + List<Snapshot> snapshots() { + ensureLoaded(); + + return snapshots; + } + + Snapshot snapshot(long id) { + if (!snapshotsById.containsKey(id)) { + ensureLoaded(); + } + + return snapshotsById.get(id); + } + + boolean contains(long id) { + if (!snapshotsById.containsKey(id)) { + ensureLoaded(); + } + + return snapshotsById.containsKey(id); + } + + Map<String, SnapshotRef> refs() { + return refs; + } + + SnapshotRef ref(String name) { + return refs.get(name); + } + + private void ensureLoaded() { + if (!loaded && snapshotsSupplier != null) { + this.snapshots = ImmutableList.copyOf(snapshotsSupplier.get()); + this.snapshotsById = indexSnapshotsById(snapshots); + } + + if (!loaded && refsSupplier != null) { + this.refs = SerializableMap.copyOf(refsSupplier.get()); + } + + loaded = true; + } + + void validate(long currentSnapshotId, long lastSequenceNumber) { + validateSnapshots(lastSequenceNumber); + validateRefs(currentSnapshotId); + } + + private void validateSnapshots(long lastSequenceNumber) { + for (Snapshot snap : snapshots) { + ValidationException.check( + snap.sequenceNumber() <= lastSequenceNumber, + "Invalid snapshot with sequence number %s greater than last sequence number %s", + snap.sequenceNumber(), + lastSequenceNumber); + } + } + + private void validateRefs(long currentSnapshotId) { + for (SnapshotRef ref : refs.values()) { + Preconditions.checkArgument( + snapshotsById.containsKey(ref.snapshotId()), + "Snapshot for reference %s does not exist in the existing snapshots list", + ref); + } + + SnapshotRef main = refs.get(SnapshotRef.MAIN_BRANCH); + if (currentSnapshotId != -1) { + Preconditions.checkArgument( + main == null || currentSnapshotId == main.snapshotId(), + "Current snapshot ID does not match main branch (%s != %s)", + currentSnapshotId, + main != null ? main.snapshotId() : null); + } else { + Preconditions.checkArgument( + main == null, "Current snapshot is not set, but main branch exists: %s", main); + } + } + + private static Map<Long, Snapshot> indexSnapshotsById(List<Snapshot> snapshots) { + return SerializableMap.copyOf( + snapshots.stream().collect(Collectors.toMap(Snapshot::snapshotId, Function.identity()))); + } + + public static Builder buildFrom(SnapshotOperations base) { + return new Builder(base); + } + + public static Builder buildFromEmpty() { + return new Builder(); + } + + public static SnapshotOperations empty() { + return SnapshotOperations.buildFromEmpty().build(); + } + + static class Builder { + private List<Snapshot> snapshots; + private SerializableSupplier<List<Snapshot>> snapshotsSupplier; + private final Map<Long, Snapshot> snapshotsById; + private Map<String, SnapshotRef> refs; + private SerializableSupplier<Map<String, SnapshotRef>> refsSupplier; + + Builder() { + this.snapshots = Lists.newArrayList(); + this.refs = Maps.newHashMap(); + + this.snapshotsById = Maps.newHashMap(); + } + + Builder(SnapshotOperations base) { + this.snapshots = Lists.newArrayList(base.snapshots); + this.snapshotsSupplier = base.snapshotsSupplier; + this.refs = Maps.newHashMap(base.refs); + this.refsSupplier = base.refsSupplier; + + this.snapshotsById = indexSnapshotsById(snapshots); + } + + Builder snapshots(List<Snapshot> snapshots1) { + this.snapshots = snapshots1; + return this; + } + + Builder snapshotsSupplier(SerializableSupplier<List<Snapshot>> snapshotsSupplier1) { + this.snapshotsSupplier = snapshotsSupplier1; + return this; + } + + Snapshot snapshot(Long id) { + return snapshotsById.get(id); + } + + Builder add(Snapshot snapshot) { + ValidationException.check( + !snapshotsById.containsKey(snapshot.snapshotId()), + "Snapshot already exists for id: %s", + snapshot.snapshotId()); + + snapshots.add(snapshot); + snapshotsById.put(snapshot.snapshotId(), snapshot); + + return this; + } + + List<Snapshot> remove(Collection<Long> idsToRemove) { Review Comment: Rather than returning the set of snapshots that were removed, what about passing callbacks that handle snapshot removal? That way this can follow the builder pattern and it can handle both snapshots that are removed as well as refs that are removed because they are dangling. -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
