org.apache.flink.runtime.state.ttl.TtlMapState Maven / Gradle / Ivy
/*
* 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.ttl;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.api.common.typeutils.base.MapSerializer;
import org.apache.flink.runtime.state.internal.InternalMapState;
import org.apache.flink.util.FlinkRuntimeException;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.AbstractMap;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.function.Function;
/**
* This class wraps map state with TTL logic.
*
* @param The type of key the state is associated to
* @param The type of the namespace
* @param Type of the user entry key of state with TTL
* @param Type of the user entry value of state with TTL
*/
class TtlMapState
extends AbstractTtlState, Map>, InternalMapState>>
implements InternalMapState {
TtlMapState(TtlStateContext>, Map> ttlStateContext) {
super(ttlStateContext);
}
@Override
public UV get(UK key) throws Exception {
TtlValue ttlValue = getWrapped(key);
return ttlValue == null ? null : ttlValue.getUserValue();
}
private TtlValue getWrapped(UK key) throws Exception {
accessCallback.run();
return getWrappedWithTtlCheckAndUpdate(
() -> original.get(key), v -> original.put(key, v), () -> original.remove(key));
}
@Override
public void put(UK key, UV value) throws Exception {
accessCallback.run();
original.put(key, wrapWithTs(value));
}
@Override
public void putAll(Map map) throws Exception {
accessCallback.run();
if (map == null) {
return;
}
Map> ttlMap = new HashMap<>(map.size());
long currentTimestamp = timeProvider.currentTimestamp();
for (Map.Entry entry : map.entrySet()) {
UK key = entry.getKey();
ttlMap.put(key, TtlUtils.wrapWithTs(entry.getValue(), currentTimestamp));
}
original.putAll(ttlMap);
}
@Override
public void remove(UK key) throws Exception {
accessCallback.run();
original.remove(key);
}
@Override
public boolean contains(UK key) throws Exception {
TtlValue ttlValue = getWrapped(key);
return ttlValue != null;
}
@Override
public Iterable> entries() throws Exception {
return entries(e -> e);
}
private Iterable entries(
Function, R> resultMapper) throws Exception {
accessCallback.run();
Iterable>> withTs = original.entries();
return () -> new EntriesIterator<>(withTs == null ? Collections.emptyList() : withTs, resultMapper);
}
@Override
public Iterable keys() throws Exception {
return entries(Map.Entry::getKey);
}
@Override
public Iterable values() throws Exception {
return entries(Map.Entry::getValue);
}
@Override
public Iterator> iterator() throws Exception {
return entries().iterator();
}
@Nullable
@Override
public Map> getUnexpiredOrNull(@Nonnull Map> ttlValue) {
Map> unexpired = new HashMap<>();
TypeSerializer> valueSerializer =
((MapSerializer>) original.getValueSerializer()).getValueSerializer();
for (Map.Entry> e : ttlValue.entrySet()) {
if (!expired(e.getValue())) {
// we have to do the defensive copy to update the value
unexpired.put(e.getKey(), valueSerializer.copy(e.getValue()));
}
}
return ttlValue.size() == unexpired.size() ? ttlValue : unexpired;
}
@Override
public void clear() {
original.clear();
}
private class EntriesIterator implements Iterator {
private final Iterator>> originalIterator;
private final Function, R> resultMapper;
private Map.Entry nextUnexpired = null;
private boolean rightAfterNextIsCalled = false;
private EntriesIterator(
@Nonnull Iterable>> withTs,
@Nonnull Function, R> resultMapper) {
this.originalIterator = withTs.iterator();
this.resultMapper = resultMapper;
}
@Override
public boolean hasNext() {
rightAfterNextIsCalled = false;
while (nextUnexpired == null && originalIterator.hasNext()) {
nextUnexpired = getUnexpiredAndUpdateOrCleanup(originalIterator.next());
}
return nextUnexpired != null;
}
@Override
public R next() {
if (hasNext()) {
rightAfterNextIsCalled = true;
R result = resultMapper.apply(nextUnexpired);
nextUnexpired = null;
return result;
}
throw new NoSuchElementException();
}
@Override
public void remove() {
if (rightAfterNextIsCalled) {
originalIterator.remove();
} else {
throw new IllegalStateException("next() has not been called or hasNext() has been called afterwards," +
" remove() is supported only right after calling next()");
}
}
private Map.Entry getUnexpiredAndUpdateOrCleanup(Map.Entry> e) {
TtlValue unexpiredValue;
try {
unexpiredValue = getWrappedWithTtlCheckAndUpdate(
e::getValue,
v -> original.put(e.getKey(), v),
originalIterator::remove);
} catch (Exception ex) {
throw new FlinkRuntimeException(ex);
}
return unexpiredValue == null ? null : new AbstractMap.SimpleEntry<>(e.getKey(), unexpiredValue.getUserValue());
}
}
}