com.datastax.dse.driver.api.core.graph.reactive.ReactiveGraphResultSet Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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package com.datastax.dse.driver.api.core.graph.reactive;
import com.datastax.dse.driver.api.core.graph.GraphStatement;
import com.datastax.oss.driver.api.core.cql.ExecutionInfo;
import edu.umd.cs.findbugs.annotations.NonNull;
import org.reactivestreams.Publisher;
/**
* A {@link Publisher} of {@link ReactiveGraphNode}s returned by a {@link ReactiveGraphSession}.
*
* By default, all implementations returned by the driver are cold, unicast, single-subscriber
* only publishers. In other words, they do not support multiple subscriptions; consider
* caching the results produced by such publishers if you need to consume them by more than one
* downstream subscriber.
*
*
Also, note that reactive graph result sets may emit items to their subscribers on an internal
* driver IO thread. Subscriber implementors are encouraged to abide by Reactive Streams
* Specification rule 2.2 and avoid performing heavy computations or blocking calls inside
* {@link org.reactivestreams.Subscriber#onNext(Object) onNext} calls, as doing so could slow down
* the driver and impact performance. Instead, they should asynchronously dispatch received signals
* to their processing logic.
*
*
This interface exists mainly to expose useful information about {@linkplain
* #getExecutionInfos() request execution}. This is particularly convenient for queries that do not
* return rows; for queries that do return rows, it is also possible, and oftentimes easier, to
* access that same information {@linkplain ReactiveGraphNode at node level}.
*
* @see ReactiveGraphSession#executeReactive(GraphStatement)
* @see ReactiveGraphNode
*/
public interface ReactiveGraphResultSet extends Publisher {
/**
* Returns {@linkplain ExecutionInfo information about the execution} of all requests that have
* been performed so far to assemble this result set.
*
* If the query is not paged, this publisher will emit exactly one item as soon as the response
* arrives, then complete. If the query is paged, it will emit multiple items, one per page; then
* it will complete when the last page arrives. If the query execution fails, then this publisher
* will fail with the same error.
*
*
By default, publishers returned by this method do not support multiple subscriptions.
*
* @see ReactiveGraphNode#getExecutionInfo()
*/
@NonNull
Publisher getExecutionInfos();
}