Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* 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.streams.state.internals;
import org.apache.kafka.common.serialization.Serializer;
import org.apache.kafka.common.utils.Bytes;
import org.apache.kafka.streams.KeyValue;
import org.apache.kafka.streams.processor.ProcessorContext;
import org.apache.kafka.streams.processor.StateStore;
import org.apache.kafka.streams.state.KeyValueIterator;
import org.apache.kafka.streams.state.KeyValueStore;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Iterator;
import java.util.List;
import java.util.NavigableMap;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.Objects;
public class InMemoryKeyValueStore implements KeyValueStore {
private static final Logger LOG = LoggerFactory.getLogger(InMemoryKeyValueStore.class);
private final String name;
private final NavigableMap map = new TreeMap<>();
private volatile boolean open = false;
private long size = 0L; // SkipListMap#size is O(N) so we just do our best to track it
public InMemoryKeyValueStore(final String name) {
this.name = name;
}
@Override
public String name() {
return name;
}
@Deprecated
@Override
public void init(final ProcessorContext context,
final StateStore root) {
size = 0;
if (root != null) {
// register the store
context.register(root, (key, value) -> put(Bytes.wrap(key), value));
}
open = true;
}
@Override
public boolean persistent() {
return false;
}
@Override
public boolean isOpen() {
return open;
}
@Override
public synchronized byte[] get(final Bytes key) {
return map.get(key);
}
@Override
public synchronized void put(final Bytes key, final byte[] value) {
if (value == null) {
size -= map.remove(key) == null ? 0 : 1;
} else {
size += map.put(key, value) == null ? 1 : 0;
}
}
@Override
public synchronized byte[] putIfAbsent(final Bytes key, final byte[] value) {
final byte[] originalValue = get(key);
if (originalValue == null) {
put(key, value);
}
return originalValue;
}
@Override
public void putAll(final List> entries) {
for (final KeyValue entry : entries) {
put(entry.key, entry.value);
}
}
@Override
public , P> KeyValueIterator prefixScan(final P prefix, final PS prefixKeySerializer) {
Objects.requireNonNull(prefix, "prefix cannot be null");
Objects.requireNonNull(prefixKeySerializer, "prefixKeySerializer cannot be null");
final Bytes from = Bytes.wrap(prefixKeySerializer.serialize(null, prefix));
final Bytes to = Bytes.increment(from);
return new DelegatingPeekingKeyValueIterator<>(
name,
new InMemoryKeyValueIterator(map.subMap(from, true, to, false).keySet(), true)
);
}
@Override
public synchronized byte[] delete(final Bytes key) {
final byte[] oldValue = map.remove(key);
size -= oldValue == null ? 0 : 1;
return oldValue;
}
@Override
public synchronized KeyValueIterator range(final Bytes from, final Bytes to) {
return range(from, to, true);
}
@Override
public synchronized KeyValueIterator reverseRange(final Bytes from, final Bytes to) {
return range(from, to, false);
}
private KeyValueIterator range(final Bytes from, final Bytes to, final boolean forward) {
if (from.compareTo(to) > 0) {
LOG.warn("Returning empty iterator for fetch with invalid key range: from > to. " +
"This may be due to range arguments set in the wrong order, " +
"or serdes that don't preserve ordering when lexicographically comparing the serialized bytes. " +
"Note that the built-in numerical serdes do not follow this for negative numbers");
return KeyValueIterators.emptyIterator();
}
return new DelegatingPeekingKeyValueIterator<>(
name,
new InMemoryKeyValueIterator(map.subMap(from, true, to, true).keySet(), forward));
}
@Override
public synchronized KeyValueIterator all() {
return new DelegatingPeekingKeyValueIterator<>(
name,
new InMemoryKeyValueIterator(map.keySet(), true));
}
@Override
public synchronized KeyValueIterator reverseAll() {
return new DelegatingPeekingKeyValueIterator<>(
name,
new InMemoryKeyValueIterator(map.keySet(), false));
}
@Override
public long approximateNumEntries() {
return size;
}
@Override
public void flush() {
// do-nothing since it is in-memory
}
@Override
public void close() {
map.clear();
size = 0;
open = false;
}
private class InMemoryKeyValueIterator implements KeyValueIterator {
private final Iterator iter;
private InMemoryKeyValueIterator(final Set keySet, final boolean forward) {
if (forward) {
this.iter = new TreeSet<>(keySet).iterator();
} else {
this.iter = new TreeSet<>(keySet).descendingIterator();
}
}
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public KeyValue next() {
final Bytes key = iter.next();
return new KeyValue<>(key, map.get(key));
}
@Override
public void close() {
// do nothing
}
@Override
public Bytes peekNextKey() {
throw new UnsupportedOperationException("peekNextKey() not supported in " + getClass().getName());
}
}
}
