org.apache.kafka.timeline.TimelineHashMap 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.kafka.timeline;
import java.util.AbstractCollection;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
/**
* This is a hash map which can be snapshotted.
*
* See {@SnapshottableHashTable} for more details about the implementation.
*
* This class requires external synchronization. Null keys and values are not supported.
*
* @param The key type of the set.
* @param The value type of the set.
*/
public class TimelineHashMap
extends SnapshottableHashTable>
implements Map {
static class TimelineHashMapEntry
implements SnapshottableHashTable.ElementWithStartEpoch, Map.Entry {
private final K key;
private final V value;
private long startEpoch;
TimelineHashMapEntry(K key, V value) {
this.key = key;
this.value = value;
this.startEpoch = SnapshottableHashTable.LATEST_EPOCH;
}
@Override
public K getKey() {
return key;
}
@Override
public V getValue() {
return value;
}
@Override
public V setValue(V value) {
// This would be inefficient to support since we'd need a back-reference
// to the enclosing map in each Entry object. There would also be
// complications if this entry object was sourced from a historical iterator;
// we don't support modifying the past. Since we don't really need this API,
// let's just not support it.
throw new UnsupportedOperationException();
}
@Override
public void setStartEpoch(long startEpoch) {
this.startEpoch = startEpoch;
}
@Override
public long startEpoch() {
return startEpoch;
}
@SuppressWarnings("unchecked")
@Override
public boolean equals(Object o) {
if (!(o instanceof TimelineHashMapEntry)) return false;
TimelineHashMapEntry other = (TimelineHashMapEntry) o;
return key.equals(other.key);
}
@Override
public int hashCode() {
return key.hashCode();
}
}
public TimelineHashMap(SnapshotRegistry snapshotRegistry, int expectedSize) {
super(snapshotRegistry, expectedSize);
}
@Override
public int size() {
return size(SnapshottableHashTable.LATEST_EPOCH);
}
public int size(long epoch) {
return snapshottableSize(epoch);
}
@Override
public boolean isEmpty() {
return isEmpty(SnapshottableHashTable.LATEST_EPOCH);
}
public boolean isEmpty(long epoch) {
return snapshottableSize(epoch) == 0;
}
@Override
public boolean containsKey(Object key) {
return containsKey(key, SnapshottableHashTable.LATEST_EPOCH);
}
public boolean containsKey(Object key, long epoch) {
return snapshottableGet(new TimelineHashMapEntry<>(key, null), epoch) != null;
}
@Override
public boolean containsValue(Object value) {
Iterator> iter = entrySet().iterator();
while (iter.hasNext()) {
Entry e = iter.next();
if (value.equals(e.getValue())) {
return true;
}
}
return false;
}
@Override
public V get(Object key) {
return get(key, SnapshottableHashTable.LATEST_EPOCH);
}
public V get(Object key, long epoch) {
Entry entry =
snapshottableGet(new TimelineHashMapEntry<>(key, null), epoch);
if (entry == null) {
return null;
}
return entry.getValue();
}
@Override
public V put(K key, V value) {
Objects.requireNonNull(key);
Objects.requireNonNull(value);
TimelineHashMapEntry entry = new TimelineHashMapEntry<>(key, value);
TimelineHashMapEntry prev = snapshottableAddOrReplace(entry);
if (prev == null) {
return null;
}
return prev.getValue();
}
@Override
public V remove(Object key) {
TimelineHashMapEntry result = snapshottableRemove(
new TimelineHashMapEntry<>(key, null));
return result == null ? null : result.value;
}
@Override
public void putAll(Map map) {
for (Map.Entry e : map.entrySet()) {
put(e.getKey(), e.getValue());
}
}
@Override
public void clear() {
reset();
}
final class KeySet extends AbstractSet {
private final long epoch;
KeySet(long epoch) {
this.epoch = epoch;
}
public int size() {
return TimelineHashMap.this.size(epoch);
}
public void clear() {
if (epoch != SnapshottableHashTable.LATEST_EPOCH) {
throw new RuntimeException("can't modify snapshot");
}
TimelineHashMap.this.clear();
}
public Iterator iterator() {
return new KeyIterator(epoch);
}
public boolean contains(Object o) {
return TimelineHashMap.this.containsKey(o, epoch);
}
public boolean remove(Object o) {
if (epoch != SnapshottableHashTable.LATEST_EPOCH) {
throw new RuntimeException("can't modify snapshot");
}
return TimelineHashMap.this.remove(o) != null;
}
}
final class KeyIterator implements Iterator {
private final Iterator> iter;
KeyIterator(long epoch) {
this.iter = snapshottableIterator(epoch);
}
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public K next() {
TimelineHashMapEntry next = iter.next();
return next.getKey();
}
@Override
public void remove() {
iter.remove();
}
}
@Override
public Set keySet() {
return keySet(SnapshottableHashTable.LATEST_EPOCH);
}
public Set keySet(long epoch) {
return new KeySet(epoch);
}
final class Values extends AbstractCollection {
private final long epoch;
Values(long epoch) {
this.epoch = epoch;
}
public int size() {
return TimelineHashMap.this.size(epoch);
}
public void clear() {
if (epoch != SnapshottableHashTable.LATEST_EPOCH) {
throw new RuntimeException("can't modify snapshot");
}
TimelineHashMap.this.clear();
}
public Iterator iterator() {
return new ValueIterator(epoch);
}
public boolean contains(Object o) {
return TimelineHashMap.this.containsKey(o, epoch);
}
}
final class ValueIterator implements Iterator {
private final Iterator> iter;
ValueIterator(long epoch) {
this.iter = snapshottableIterator(epoch);
}
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public V next() {
TimelineHashMapEntry next = iter.next();
return next.getValue();
}
@Override
public void remove() {
iter.remove();
}
}
@Override
public Collection values() {
return values(SnapshottableHashTable.LATEST_EPOCH);
}
public Collection values(long epoch) {
return new Values(epoch);
}
final class EntrySet extends AbstractSet> {
private final long epoch;
EntrySet(long epoch) {
this.epoch = epoch;
}
public int size() {
return TimelineHashMap.this.size(epoch);
}
public void clear() {
if (epoch != SnapshottableHashTable.LATEST_EPOCH) {
throw new RuntimeException("can't modify snapshot");
}
TimelineHashMap.this.clear();
}
public Iterator> iterator() {
return new EntryIterator(epoch);
}
public boolean contains(Object o) {
return snapshottableGet(o, epoch) != null;
}
public boolean remove(Object o) {
if (epoch != SnapshottableHashTable.LATEST_EPOCH) {
throw new RuntimeException("can't modify snapshot");
}
return snapshottableRemove(new TimelineHashMapEntry<>(o, null)) != null;
}
}
final class EntryIterator implements Iterator> {
private final Iterator> iter;
EntryIterator(long epoch) {
this.iter = snapshottableIterator(epoch);
}
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public Map.Entry next() {
return iter.next();
}
@Override
public void remove() {
iter.remove();
}
}
@Override
public Set> entrySet() {
return entrySet(SnapshottableHashTable.LATEST_EPOCH);
}
public Set> entrySet(long epoch) {
return new EntrySet(epoch);
}
@Override
public int hashCode() {
int hash = 0;
Iterator> iter = entrySet().iterator();
while (iter.hasNext()) {
hash += iter.next().hashCode();
}
return hash;
}
@Override
public boolean equals(Object o) {
if (o == this)
return true;
if (!(o instanceof Map))
return false;
Map m = (Map) o;
if (m.size() != size())
return false;
try {
Iterator> iter = entrySet().iterator();
while (iter.hasNext()) {
Entry entry = iter.next();
if (!m.get(entry.getKey()).equals(entry.getValue())) {
return false;
}
}
} catch (ClassCastException unused) {
return false;
}
return true;
}
}