com.datastax.dse.driver.api.core.cql.continuous.reactive.ContinuousReactiveSession 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.cql.continuous.reactive;
import com.datastax.dse.driver.api.core.cql.continuous.ContinuousSession;
import com.datastax.dse.driver.api.core.cql.reactive.ReactiveRow;
import com.datastax.dse.driver.internal.core.cql.continuous.reactive.ContinuousCqlRequestReactiveProcessor;
import com.datastax.oss.driver.api.core.cql.SimpleStatement;
import com.datastax.oss.driver.api.core.cql.Statement;
import com.datastax.oss.driver.api.core.session.Session;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Objects;
import org.reactivestreams.Publisher;
/**
* A {@link Session} that offers utility methods to issue queries using reactive-style programming
* and continuous paging, combined together.
*
* Methods in this interface all return {@link ContinuousReactiveResultSet} instances. All
* publishers support multiple subscriptions in a unicast fashion: each subscriber triggers an
* independent request execution and gets its own copy of the results.
*
*
Also, note that the publishers 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.
*
* @see ReactiveRow
*/
public interface ContinuousReactiveSession extends Session {
/**
* Returns a {@link Publisher} that, once subscribed to, executes the given query continuously and
* emits all the results.
*
*
See {@link ContinuousSession} for more explanations about continuous paging.
*
*
This feature is only available with Datastax Enterprise. Executing continuous queries
* against an Apache Cassandra® cluster will result in a runtime error.
*
* @param query the query to execute.
* @return The {@link Publisher} that will publish the returned results.
*/
@NonNull
default ContinuousReactiveResultSet executeContinuouslyReactive(@NonNull String query) {
return executeContinuouslyReactive(SimpleStatement.newInstance(query));
}
/**
* Returns a {@link Publisher} that, once subscribed to, executes the given query continuously and
* emits all the results.
*
*
See {@link ContinuousSession} for more explanations about continuous paging.
*
*
This feature is only available with Datastax Enterprise. Executing continuous queries
* against an Apache Cassandra® cluster will result in a runtime error.
*
* @param statement the statement to execute.
* @return The {@link Publisher} that will publish the returned results.
*/
@NonNull
default ContinuousReactiveResultSet executeContinuouslyReactive(@NonNull Statement statement) {
return Objects.requireNonNull(
execute(statement, ContinuousCqlRequestReactiveProcessor.CONTINUOUS_REACTIVE_RESULT_SET));
}
}