com.datastax.dse.driver.api.core.graph.GraphResultSet Maven / Gradle / Ivy
/*
* Copyright DataStax, Inc.
*
* 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.datastax.dse.driver.api.core.graph;
import com.datastax.dse.driver.internal.core.graph.GraphExecutionInfoConverter;
import com.datastax.oss.driver.api.core.cql.ExecutionInfo;
import com.datastax.oss.driver.shaded.guava.common.collect.ImmutableList;
import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.Nullable;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
/**
* The result of a synchronous Graph query.
*
* This object is a container for {@link GraphNode} objects that will contain the data returned
* by Graph queries.
*
*
Note that this object can only be iterated once: items are "consumed" as they are read,
* subsequent calls to {@code iterator()} will return the same iterator instance.
*
*
The default implementation returned by the driver is not thread-safe. It can only be
* iterated by the thread that invoked {@code dseSession.execute}.
*
* @see GraphNode
* @see GraphSession#execute(GraphStatement)
*/
public interface GraphResultSet extends Iterable {
/**
* Returns the next node, or {@code null} if the result set is exhausted.
*
* This is convenient for queries that are known to return exactly one row, for example count
* queries.
*/
@Nullable
default GraphNode one() {
Iterator graphNodeIterator = iterator();
return graphNodeIterator.hasNext() ? graphNodeIterator.next() : null;
}
/**
* Returns all the remaining nodes as a list; not recommended for paginated queries that return
* a large number of nodes.
*
* At this time (DSE 6.0.0), graph queries are not paginated and the server sends all the
* results at once.
*/
@NonNull
default List all() {
if (!iterator().hasNext()) {
return Collections.emptyList();
}
return ImmutableList.copyOf(this);
}
/**
* Cancels the query and asks the server to stop sending results.
*
* At this time (DSE 6.0.0), graph queries are not paginated and the server sends all the
* results at once; therefore this method has no effect.
*/
void cancel();
/**
* The execution information for the query that have been performed to assemble this result set.
*/
@NonNull
default ExecutionInfo getRequestExecutionInfo() {
return GraphExecutionInfoConverter.convert(getExecutionInfo());
}
/** @deprecated Use {@link #getRequestExecutionInfo()} instead. */
@Deprecated
@NonNull
com.datastax.dse.driver.api.core.graph.GraphExecutionInfo getExecutionInfo();
}