/*
* 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.utils.Bytes;
import org.apache.kafka.streams.KeyValue;
import org.apache.kafka.streams.errors.InvalidStateStoreException;
import org.apache.kafka.streams.state.KeyValueIterator;
import org.apache.kafka.streams.state.KeyValueStore;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* Iterate over multiple Segments
*/
class SegmentIterator implements KeyValueIterator<Bytes, byte[]> {
private final Bytes from;
private final Bytes to;
private final Iterator<Segment> segments;
private final HasNextCondition hasNextCondition;
private KeyValueStore<Bytes, byte[]> currentSegment;
private KeyValueIterator<Bytes, byte[]> currentIterator;
SegmentIterator(final Iterator<Segment> segments,
final HasNextCondition hasNextCondition,
final Bytes from,
final Bytes to) {
this.segments = segments;
this.hasNextCondition = hasNextCondition;
this.from = from;
this.to = to;
}
public void close() {
if (currentIterator != null) {
currentIterator.close();
currentIterator = null;
}
}
@Override
public Bytes peekNextKey() {
if (!hasNext()) {
throw new NoSuchElementException();
}
return currentIterator.peekNextKey();
}
@Override
public boolean hasNext() {
boolean hasNext = false;
while ((currentIterator == null || !(hasNext = hasNextCondition.hasNext(currentIterator)) || !currentSegment.isOpen())
&& segments.hasNext()) {
close();
currentSegment = segments.next();
try {
currentIterator = currentSegment.range(from, to);
} catch (InvalidStateStoreException e) {
// segment may have been closed so we ignore it.
}
}
return currentIterator != null && hasNext;
}
public KeyValue<Bytes, byte[]> next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
return currentIterator.next();
}
public void remove() {
throw new UnsupportedOperationException("remove() is not supported in " + getClass().getName());
}
}