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Posted to commits@flink.apache.org by dw...@apache.org on 2021/02/09 17:36:10 UTC
[flink] 02/03: [FLINK-21206] Implement HeapKeyValueStateIterator
This is an automated email from the ASF dual-hosted git repository.
dwysakowicz pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/flink.git
commit d67ace2395e21188ad9663e36a1caaf357867897
Author: Dawid Wysakowicz <dw...@apache.org>
AuthorDate: Mon Jan 25 09:05:49 2021 +0100
[FLINK-21206] Implement HeapKeyValueStateIterator
---
.../flink/runtime/state/KeyValueStateIterator.java | 4 +-
.../state/heap/HeapKeyValueStateIterator.java | 407 +++++++++++++++++++++
2 files changed, 410 insertions(+), 1 deletion(-)
diff --git a/flink-runtime/src/main/java/org/apache/flink/runtime/state/KeyValueStateIterator.java b/flink-runtime/src/main/java/org/apache/flink/runtime/state/KeyValueStateIterator.java
index 28a3266..cf9cf16 100644
--- a/flink-runtime/src/main/java/org/apache/flink/runtime/state/KeyValueStateIterator.java
+++ b/flink-runtime/src/main/java/org/apache/flink/runtime/state/KeyValueStateIterator.java
@@ -18,6 +18,8 @@
package org.apache.flink.runtime.state;
+import java.io.IOException;
+
/**
* Iterator that over all key-value state entries in a {@link KeyedStateBackend}. For use during
* snapshotting.
@@ -31,7 +33,7 @@ public interface KeyValueStateIterator extends AutoCloseable {
* Advances the iterator. Should only be called if {@link #isValid()} returned true. Valid flag
* can only change after calling {@link #next()}.
*/
- void next();
+ void next() throws IOException;
/** Returns the key-group for the current key. */
int keyGroup();
diff --git a/flink-runtime/src/main/java/org/apache/flink/runtime/state/heap/HeapKeyValueStateIterator.java b/flink-runtime/src/main/java/org/apache/flink/runtime/state/heap/HeapKeyValueStateIterator.java
new file mode 100644
index 0000000..f5f11e8
--- /dev/null
+++ b/flink-runtime/src/main/java/org/apache/flink/runtime/state/heap/HeapKeyValueStateIterator.java
@@ -0,0 +1,407 @@
+/*
+ * 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.flink.runtime.state.heap;
+
+import org.apache.flink.annotation.Internal;
+import org.apache.flink.api.common.typeutils.TypeSerializer;
+import org.apache.flink.api.common.typeutils.base.ListSerializer;
+import org.apache.flink.api.common.typeutils.base.MapSerializer;
+import org.apache.flink.core.memory.DataOutputSerializer;
+import org.apache.flink.runtime.state.CompositeKeySerializationUtils;
+import org.apache.flink.runtime.state.IterableStateSnapshot;
+import org.apache.flink.runtime.state.KeyGroupRange;
+import org.apache.flink.runtime.state.KeyValueStateIterator;
+import org.apache.flink.runtime.state.ListDelimitedSerializer;
+import org.apache.flink.runtime.state.RegisteredKeyValueStateBackendMetaInfo;
+import org.apache.flink.runtime.state.RegisteredPriorityQueueStateBackendMetaInfo;
+import org.apache.flink.runtime.state.SerializedCompositeKeyBuilder;
+import org.apache.flink.runtime.state.StateEntry;
+import org.apache.flink.runtime.state.StateSnapshot;
+
+import javax.annotation.Nonnegative;
+import javax.annotation.Nonnull;
+import javax.annotation.concurrent.NotThreadSafe;
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import static org.apache.flink.util.Preconditions.checkNotNull;
+
+/**
+ * A {@link org.apache.flink.runtime.state.KeyValueStateIterator} over Heap backend snapshot
+ * resources.
+ */
+@Internal
+@NotThreadSafe
+public final class HeapKeyValueStateIterator implements KeyValueStateIterator {
+
+ private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
+
+ private final Map<StateUID, Integer> stateNamesToId;
+ private final Map<StateUID, StateSnapshot> stateStableSnapshots;
+ private final int keyGroupPrefixBytes;
+
+ private boolean isValid;
+ private boolean newKeyGroup;
+ private boolean newKVState;
+ private byte[] currentKey;
+ private byte[] currentValue;
+
+ /** Iterator over the key groups of the corresponding key group range. */
+ private final Iterator<Integer> keyGroupIterator;
+ /** The current value of the keyGroupIterator. */
+ private int currentKeyGroup;
+
+ /** Iterator over all states present in the snapshots. */
+ private Iterator<StateUID> statesIterator;
+ /** The current value of the statesIterator. */
+ private StateUID currentState;
+ /**
+ * An iterator over the values of the current state. It can be one of three:
+ *
+ * <ul>
+ * <li>{@link QueueIterator} for iterating over entries in a priority queue
+ * <li>{@link StateTableIterator} for iterating over entries in a StateTable
+ * <li>{@link MapStateIterator} for iterating over entries in a user map, this one falls back
+ * to the upper one automatically if exhausted
+ * </ul>
+ */
+ private SingleStateIterator currentStateIterator;
+ /** Helpers for serializing state into the unified format. */
+ private final DataOutputSerializer valueOut = new DataOutputSerializer(64);
+
+ private final ListDelimitedSerializer listDelimitedSerializer = new ListDelimitedSerializer();
+ private final SerializedCompositeKeyBuilder<Object> compositeKeyBuilder;
+
+ public HeapKeyValueStateIterator(
+ @Nonnull final KeyGroupRange keyGroupRange,
+ @Nonnull final TypeSerializer<?> keySerializer,
+ @Nonnegative final int totalKeyGroups,
+ @Nonnull final Map<StateUID, Integer> stateNamesToId,
+ @Nonnull final Map<StateUID, StateSnapshot> stateSnapshots)
+ throws IOException {
+ checkNotNull(keyGroupRange);
+ checkNotNull(keySerializer);
+ this.stateNamesToId = checkNotNull(stateNamesToId);
+ this.stateStableSnapshots = checkNotNull(stateSnapshots);
+
+ this.statesIterator = stateSnapshots.keySet().iterator();
+ this.keyGroupIterator = keyGroupRange.iterator();
+
+ this.keyGroupPrefixBytes =
+ CompositeKeySerializationUtils.computeRequiredBytesInKeyGroupPrefix(totalKeyGroups);
+ this.compositeKeyBuilder =
+ new SerializedCompositeKeyBuilder<>(
+ castToType(keySerializer), keyGroupPrefixBytes, 32);
+
+ if (!keyGroupIterator.hasNext() || !statesIterator.hasNext()) {
+ // stop early, no key groups or states
+ isValid = false;
+ } else {
+ currentKeyGroup = keyGroupIterator.next();
+ next();
+ this.newKeyGroup = true;
+ }
+ }
+
+ @Override
+ public boolean isValid() {
+ return isValid;
+ }
+
+ @Override
+ public boolean isNewKeyValueState() {
+ return this.newKVState;
+ }
+
+ @Override
+ public boolean isNewKeyGroup() {
+ return this.newKeyGroup;
+ }
+
+ @Override
+ public int keyGroup() {
+ return currentKeyGroup;
+ }
+
+ @Override
+ public int kvStateId() {
+ return stateNamesToId.get(currentState);
+ }
+
+ @Override
+ public void next() throws IOException {
+ boolean hasStateEntry = false;
+
+ this.newKVState = false;
+ this.newKeyGroup = false;
+
+ do {
+ if (currentState == null) {
+ boolean hasNextState = moveToNextState();
+ if (!hasNextState) {
+ break;
+ }
+ }
+
+ hasStateEntry = currentStateIterator != null && currentStateIterator.hasNext();
+ if (!hasStateEntry) {
+ this.currentState = null;
+ }
+ } while (!hasStateEntry);
+
+ if (hasStateEntry) {
+ isValid = true;
+ currentStateIterator.writeOutNext();
+ } else {
+ isValid = false;
+ }
+ }
+
+ private boolean moveToNextState() throws IOException {
+ if (statesIterator.hasNext()) {
+ this.currentState = statesIterator.next();
+ this.newKVState = true;
+ } else if (keyGroupIterator.hasNext()) {
+ this.currentKeyGroup = keyGroupIterator.next();
+ resetStates();
+ this.newKeyGroup = true;
+ this.newKVState = true;
+ } else {
+ return false;
+ }
+
+ StateSnapshot stateSnapshot = this.stateStableSnapshots.get(currentState);
+ setCurrentStateIterator(stateSnapshot);
+
+ // set to a valid entry
+ return true;
+ }
+
+ private void resetStates() {
+ this.statesIterator = stateStableSnapshots.keySet().iterator();
+ this.currentState = statesIterator.next();
+ }
+
+ @SuppressWarnings("unchecked")
+ private void setCurrentStateIterator(StateSnapshot stateSnapshot) throws IOException {
+ if (stateSnapshot instanceof IterableStateSnapshot) {
+ RegisteredKeyValueStateBackendMetaInfo<Object, Object> metaInfo =
+ new RegisteredKeyValueStateBackendMetaInfo<>(
+ stateSnapshot.getMetaInfoSnapshot());
+ Iterator<? extends StateEntry<?, ?, ?>> snapshotIterator =
+ ((IterableStateSnapshot<?, ?, ?>) stateSnapshot).getIterator(currentKeyGroup);
+ this.currentStateIterator = new StateTableIterator(snapshotIterator, metaInfo);
+ } else if (stateSnapshot instanceof HeapPriorityQueueStateSnapshot) {
+ Iterator<Object> snapshotIterator =
+ ((HeapPriorityQueueStateSnapshot<Object>) stateSnapshot)
+ .getIteratorForKeyGroup(currentKeyGroup);
+ RegisteredPriorityQueueStateBackendMetaInfo<Object> metaInfo =
+ new RegisteredPriorityQueueStateBackendMetaInfo<>(
+ stateSnapshot.getMetaInfoSnapshot());
+ this.currentStateIterator = new QueueIterator<>(snapshotIterator, metaInfo);
+ } else {
+ throw new IllegalStateException("Unknown snapshot type: " + stateSnapshot);
+ }
+ }
+
+ /** A common interface for writing out a single entry in a state. */
+ private interface SingleStateIterator {
+
+ boolean hasNext();
+
+ void writeOutNext() throws IOException;
+ }
+
+ private final class StateTableIterator implements SingleStateIterator {
+
+ private final Iterator<? extends StateEntry<?, ?, ?>> entriesIterator;
+ private final RegisteredKeyValueStateBackendMetaInfo<?, ?> stateSnapshot;
+
+ private StateTableIterator(
+ Iterator<? extends StateEntry<?, ?, ?>> entriesIterator,
+ RegisteredKeyValueStateBackendMetaInfo<?, ?> stateSnapshot) {
+ this.entriesIterator = entriesIterator;
+ this.stateSnapshot = stateSnapshot;
+ }
+
+ @Override
+ public boolean hasNext() {
+ return entriesIterator.hasNext();
+ }
+
+ @Override
+ public void writeOutNext() throws IOException {
+ StateEntry<?, ?, ?> currentEntry = entriesIterator.next();
+ valueOut.clear();
+ compositeKeyBuilder.setKeyAndKeyGroup(currentEntry.getKey(), keyGroup());
+ compositeKeyBuilder.setNamespace(
+ currentEntry.getNamespace(),
+ castToType(stateSnapshot.getNamespaceSerializer()));
+ TypeSerializer<?> stateSerializer = stateSnapshot.getStateSerializer();
+ switch (stateSnapshot.getStateType()) {
+ case AGGREGATING:
+ case REDUCING:
+ case FOLDING:
+ case VALUE:
+ writeOutValue(currentEntry, stateSerializer);
+ break;
+ case LIST:
+ writeOutList(currentEntry, stateSerializer);
+ break;
+ case MAP:
+ writeOutMap(currentEntry, stateSerializer);
+ break;
+ default:
+ throw new IllegalStateException("");
+ }
+ }
+
+ private void writeOutValue(
+ StateEntry<?, ?, ?> currentEntry, TypeSerializer<?> stateSerializer)
+ throws IOException {
+ currentKey = compositeKeyBuilder.build();
+ castToType(stateSerializer).serialize(currentEntry.getState(), valueOut);
+ currentValue = valueOut.getCopyOfBuffer();
+ }
+
+ @SuppressWarnings("unchecked")
+ private void writeOutList(
+ StateEntry<?, ?, ?> currentEntry, TypeSerializer<?> stateSerializer)
+ throws IOException {
+ ListSerializer<Object> listSerializer = (ListSerializer<Object>) stateSerializer;
+ currentKey = compositeKeyBuilder.build();
+ currentValue =
+ listDelimitedSerializer.serializeList(
+ (List<Object>) currentEntry.getState(),
+ listSerializer.getElementSerializer());
+ }
+
+ @SuppressWarnings("unchecked")
+ private void writeOutMap(
+ StateEntry<?, ?, ?> currentEntry, TypeSerializer<?> stateSerializer)
+ throws IOException {
+ MapSerializer<Object, Object> mapSerializer =
+ (MapSerializer<Object, Object>) stateSerializer;
+ currentStateIterator =
+ new MapStateIterator(
+ (Map<Object, Object>) currentEntry.getState(),
+ mapSerializer.getKeySerializer(),
+ mapSerializer.getValueSerializer(),
+ this);
+ currentStateIterator.writeOutNext();
+ }
+ }
+
+ private final class MapStateIterator implements SingleStateIterator {
+
+ private final Iterator<Map.Entry<Object, Object>> mapEntries;
+ private final TypeSerializer<Object> userKeySerializer;
+ private final TypeSerializer<Object> userValueSerializer;
+ private final StateTableIterator parentIterator;
+
+ private MapStateIterator(
+ Map<Object, Object> mapEntries,
+ TypeSerializer<Object> userKeySerializer,
+ TypeSerializer<Object> userValueSerializer,
+ StateTableIterator parentIterator) {
+ this.mapEntries = mapEntries.entrySet().iterator();
+ this.userKeySerializer = userKeySerializer;
+ this.userValueSerializer = userValueSerializer;
+ this.parentIterator = parentIterator;
+ }
+
+ @Override
+ public boolean hasNext() {
+ // we should never end up here with an exhausted map iterator
+ // if an iterator is exhausted in the writeOutNext we switch back to
+ // the originating StateTableIterator
+ assert mapEntries.hasNext();
+ return true;
+ }
+
+ @Override
+ public void writeOutNext() throws IOException {
+ Map.Entry<Object, Object> entry = mapEntries.next();
+ valueOut.clear();
+ currentKey =
+ compositeKeyBuilder.buildCompositeKeyUserKey(entry.getKey(), userKeySerializer);
+ Object userValue = entry.getValue();
+ valueOut.writeBoolean(userValue == null);
+ userValueSerializer.serialize(userValue, valueOut);
+ currentValue = valueOut.getCopyOfBuffer();
+
+ if (!mapEntries.hasNext()) {
+ currentStateIterator = parentIterator;
+ }
+ }
+ }
+
+ private final class QueueIterator<T> implements SingleStateIterator {
+ private final Iterator<T> elementsForKeyGroup;
+ private final RegisteredPriorityQueueStateBackendMetaInfo<T> metaInfo;
+ private final DataOutputSerializer keyOut = new DataOutputSerializer(128);
+ private final int afterKeyMark;
+
+ public QueueIterator(
+ Iterator<T> elementsForKeyGroup,
+ RegisteredPriorityQueueStateBackendMetaInfo<T> metaInfo)
+ throws IOException {
+ this.elementsForKeyGroup = elementsForKeyGroup;
+ this.metaInfo = metaInfo;
+ CompositeKeySerializationUtils.writeKeyGroup(keyGroup(), keyGroupPrefixBytes, keyOut);
+ afterKeyMark = keyOut.length();
+ }
+
+ @Override
+ public boolean hasNext() {
+ return elementsForKeyGroup.hasNext();
+ }
+
+ @Override
+ public void writeOutNext() throws IOException {
+ currentValue = EMPTY_BYTE_ARRAY;
+ keyOut.setPosition(afterKeyMark);
+ T next = elementsForKeyGroup.next();
+ metaInfo.getElementSerializer().serialize(next, keyOut);
+ currentKey = keyOut.getCopyOfBuffer();
+ }
+ }
+
+ @SuppressWarnings("unchecked")
+ @Nonnull
+ private static <T> TypeSerializer<T> castToType(@Nonnull TypeSerializer<?> serializer) {
+ return (TypeSerializer<T>) serializer;
+ }
+
+ @Override
+ public byte[] key() {
+ return currentKey;
+ }
+
+ @Override
+ public byte[] value() {
+ return currentValue;
+ }
+
+ @Override
+ public void close() {}
+}