com.hazelcast.map.impl.iterator.MapQueryPartitionIterator Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2024, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.map.impl.iterator;
import com.hazelcast.internal.serialization.SerializationService;
import com.hazelcast.map.impl.operation.MapOperation;
import com.hazelcast.map.impl.proxy.MapProxyImpl;
import com.hazelcast.map.impl.query.QueryResult;
import com.hazelcast.map.impl.query.QueryResultRow;
import com.hazelcast.map.impl.query.ResultSegment;
import com.hazelcast.internal.serialization.Data;
import com.hazelcast.projection.Projection;
import com.hazelcast.query.Predicate;
import com.hazelcast.spi.impl.InternalCompletableFuture;
import com.hazelcast.spi.impl.operationservice.Operation;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
/**
* Iterator for iterating the result of the projection on entries
* in the {@code partitionId} which satisfy the {@code predicate}.
* The values are fetched in batches. The {@link Iterator#remove()} method
* is not supported and will throw a {@link UnsupportedOperationException}.
*
* NOTE
* The iteration may be done when the map is being mutated or when there are
* membership changes. The iterator does not reflect the state when it has
* been constructed - it may return some entries that were added after the
* iteration has started and may not return some entries that were removed
* after iteration has started.
* The iterator will not, however, skip an entry if it has not been changed
* and will not return an entry twice.
*/
public class MapQueryPartitionIterator extends AbstractMapQueryPartitionIterator {
private final MapProxyImpl mapProxy;
public MapQueryPartitionIterator(MapProxyImpl mapProxy, int fetchSize, int partitionId,
Predicate predicate,
Projection, R> projection) {
super(mapProxy, fetchSize, partitionId, predicate, projection);
this.mapProxy = mapProxy;
advance();
}
protected List fetch() {
final MapOperation op = mapProxy.getOperationProvider()
.createFetchWithQueryOperation(mapProxy.getName(), pointers, fetchSize, query);
final ResultSegment segment = invoke(op);
final QueryResult queryResult = (QueryResult) segment.getResult();
final List serialized = new ArrayList<>(queryResult.size());
for (QueryResultRow row : queryResult) {
serialized.add(row.getValue());
}
setLastTableIndex(serialized, segment.getPointers());
return serialized;
}
private ResultSegment invoke(Operation operation) {
final InternalCompletableFuture future =
mapProxy.getOperationService().invokeOnPartition(mapProxy.getServiceName(), operation, partitionId);
return future.joinInternal();
}
@Override
protected SerializationService getSerializationService() {
return mapProxy.getNodeEngine().getSerializationService();
}
}