Reactive implementation of the point in time API.

This PR adds the reactive implementation for the point in time API that was missing in #2273.

Original Pull Request #2275
Closes #2274

Author: sothawo

Diff for: src/main/java/org/springframework/data/elasticsearch/client/elc/ReactiveElasticsearchClient.java

@@ -276,6 +276,48 @@ public Mono<ClearScrollResponse> clearScroll(
 
 		return clearScroll(fn.apply(new ClearScrollRequest.Builder()).build());
 	}
+
+	/**
+	 * @since 5.0
+	 */
+	public Mono<OpenPointInTimeResponse> openPointInTime(OpenPointInTimeRequest request) {
+
+		Assert.notNull(request, "request must not be null");
+
+		return Mono.fromFuture(transport.performRequestAsync(request, OpenPointInTimeRequest._ENDPOINT, transportOptions));
+	}
+
+	/**
+	 * @since 5.0
+	 */
+	public Mono<OpenPointInTimeResponse> openPointInTime(
+			Function<OpenPointInTimeRequest.Builder, ObjectBuilder<OpenPointInTimeRequest>> fn) {
+
+		Assert.notNull(fn, "fn must not be null");
+
+		return openPointInTime(fn.apply(new OpenPointInTimeRequest.Builder()).build());
+	}
+
+	/**
+	 * @since 5.0
+	 */
+	public Mono<ClosePointInTimeResponse> closePointInTime(ClosePointInTimeRequest request) {
+
+		Assert.notNull(request, "request must not be null");
+
+		return Mono.fromFuture(transport.performRequestAsync(request, ClosePointInTimeRequest._ENDPOINT, transportOptions));
+	}
+
+	/**
+	 * @since 5.0
+	 */
+	public Mono<ClosePointInTimeResponse> closePointInTime(
+			Function<ClosePointInTimeRequest.Builder, ObjectBuilder<ClosePointInTimeRequest>> fn) {
+
+		Assert.notNull(fn, "fn must not be null");
+
+		return closePointInTime(fn.apply(new ClosePointInTimeRequest.Builder()).build());
+	}
 	// endregion
 
 }

Diff for: src/main/java/org/springframework/data/elasticsearch/client/elc/ReactiveElasticsearchTemplate.java

@@ -30,6 +30,7 @@
 import reactor.core.publisher.Mono;
 import reactor.util.function.Tuple2;
 
+import java.time.Duration;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
@@ -408,6 +409,30 @@ public Flux<? extends AggregationContainer<?>> aggregate(Query query, Class<?> e
 		});
 	}
 
+	@Override
+	public Mono<String> openPointInTime(IndexCoordinates index, Duration keepAlive, Boolean ignoreUnavailable) {
+
+		Assert.notNull(index, "index must not be null");
+		Assert.notNull(keepAlive, "keepAlive must not be null");
+		Assert.notNull(ignoreUnavailable, "ignoreUnavailable must not be null");
+
+		var request = requestConverter.searchOpenPointInTimeRequest(index, keepAlive, ignoreUnavailable);
+		return Mono
+				.from(execute((ClientCallback<Publisher<OpenPointInTimeResponse>>) client -> client.openPointInTime(request)))
+				.map(OpenPointInTimeResponse::id);
+	}
+
+	@Override
+	public Mono<Boolean> closePointInTime(String pit) {
+
+		Assert.notNull(pit, "pit must not be null");
+
+		ClosePointInTimeRequest request = requestConverter.searchClosePointInTime(pit);
+		return Mono
+				.from(execute((ClientCallback<Publisher<ClosePointInTimeResponse>>) client -> client.closePointInTime(request)))
+				.map(ClosePointInTimeResponse::succeeded);
+	}
+
 	// endregion
 
 	@Override

Diff for: src/main/java/org/springframework/data/elasticsearch/core/AbstractReactiveElasticsearchTemplate.java

@@ -19,6 +19,7 @@
 import reactor.core.publisher.Mono;
 import reactor.util.function.Tuple2;
 
+import java.time.Duration;
 import java.util.Collection;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -29,6 +30,7 @@
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.data.convert.EntityReader;
+import org.springframework.data.elasticsearch.client.UnsupportedClientOperationException;
 import org.springframework.data.elasticsearch.core.convert.ElasticsearchConverter;
 import org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter;
 import org.springframework.data.elasticsearch.core.document.Document;
@@ -476,6 +478,17 @@ public Mono<Long> count(Query query, Class<?> entityType, IndexCoordinates index
 	}
 
 	abstract protected Mono<Long> doCount(Query query, Class<?> entityType, IndexCoordinates index);
+
+	@Override
+	public Mono<String> openPointInTime(IndexCoordinates index, Duration keepAlive, Boolean ignoreUnavailable) {
+		throw new UnsupportedClientOperationException(getClass(), "openPointInTime");
+	}
+
+	@Override
+	public Mono<Boolean> closePointInTime(String pit) {
+		throw new UnsupportedClientOperationException(getClass(), "closePointInTime");
+	}
+
 	// endregion
 
 	// region callbacks

Diff for: src/main/java/org/springframework/data/elasticsearch/core/ReactiveSearchHits.java

@@ -72,4 +72,14 @@ public interface ReactiveSearchHits<T> {
 	 * @return wether the {@link SearchHits} has a suggest response.
 	 */
 	boolean hasSuggest();
+
+	/**
+	 * When doing a search with a point in time, the response contains a new point in time id value.
+	 *
+	 * @return the new point in time id, if one was returned from Elasticsearch
+	 * @since 5.0
+	 */
+	@Nullable
+	String getPointInTimeId();
+
 }

Diff for: src/main/java/org/springframework/data/elasticsearch/core/ReactiveSearchHitsImpl.java

@@ -78,4 +78,13 @@ public Suggest getSuggest() {
 	public boolean hasSuggest() {
 		return delegate.hasSuggest();
 	}
+
+	/**
+	 * @since 5.0
+	 */
+	@Nullable
+	@Override
+	public String getPointInTimeId() {
+		return delegate.getPointInTimeId();
+	}
 }

Diff for: src/main/java/org/springframework/data/elasticsearch/core/ReactiveSearchOperations.java

@@ -18,6 +18,7 @@
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
+import java.time.Duration;
 import java.util.List;
 
 import org.springframework.data.domain.Pageable;
@@ -271,6 +272,38 @@ <T> Mono<ReactiveSearchHits<T>> searchForHits(Query query, Class<?> entityType,
 	 */
 	Mono<Suggest> suggest(Query query, Class<?> entityType, IndexCoordinates index);
 
+	/**
+	 * Opens a point in time (pit) in Elasticsearch.
+	 *
+	 * @param index the index name(s) to use
+	 * @param keepAlive the duration the pit shoult be kept alive
+	 * @return the pit identifier
+	 * @since 5.0
+	 */
+	default Mono<String> openPointInTime(IndexCoordinates index, Duration keepAlive) {
+		return openPointInTime(index, keepAlive, false);
+	}
+
+	/**
+	 * Opens a point in time (pit) in Elasticsearch.
+	 *
+	 * @param index the index name(s) to use
+	 * @param keepAlive the duration the pit shoult be kept alive
+	 * @param ignoreUnavailable if {$literal true} the call will fail if any of the indices is missing or closed
+	 * @return the pit identifier
+	 * @since 5.0
+	 */
+	Mono<String> openPointInTime(IndexCoordinates index, Duration keepAlive, Boolean ignoreUnavailable);
+
+	/**
+	 * Closes a point in time
+	 *
+	 * @param pit the pit identifier as returned by {@link #openPointInTime(IndexCoordinates, Duration, Boolean)}
+	 * @return {@literal true} on success
+	 * @since 5.0
+	 */
+	Mono<Boolean> closePointInTime(String pit);
+
 	// region helper
 	/**
 	 * Creates a {@link Query} to find all documents. Must be implemented by the concrete implementations to provide an

Diff for: src/test/java/org/springframework/data/elasticsearch/core/ReactivePointInTimeELCIntegrationTests.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2022 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.data.elasticsearch.core;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.data.elasticsearch.junit.jupiter.ReactiveElasticsearchTemplateConfiguration;
+import org.springframework.data.elasticsearch.utils.IndexNameProvider;
+import org.springframework.test.context.ContextConfiguration;
+
+/**
+ * @author Peter-Josef Meisch
+ * @since 5.0
+ */
+@ContextConfiguration(classes = ReactivePointInTimeELCIntegrationTests.Config.class)
+public class ReactivePointInTimeELCIntegrationTests extends ReactivePointInTimeIntegrationTests {
+
+	@Configuration
+	@Import({ ReactiveElasticsearchTemplateConfiguration.class })
+	static class Config {
+		@Bean
+		IndexNameProvider indexNameProvider() {
+			return new IndexNameProvider("reactive-point-in-time");
+		}
+	}
+}

Diff for: src/test/java/org/springframework/data/elasticsearch/core/ReactivePointInTimeERHLCIntegrationTests.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2022 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.data.elasticsearch.core;
+
+import org.junit.jupiter.api.Disabled;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.data.elasticsearch.junit.jupiter.ReactiveElasticsearchRestTemplateConfiguration;
+import org.springframework.data.elasticsearch.utils.IndexNameProvider;
+import org.springframework.test.context.ContextConfiguration;
+
+/**
+ * This test class is disabled on purpose. PIT will be introduced in Spring Data Elasticsearch 5.0 where the old
+ * RestHighLevelClient and the {@link org.springframework.data.elasticsearch.client.erhlc.ElasticsearchRestTemplate} are
+ * deprecated. We therefore do not add new features to this implementation anymore. Furthermore we cannot copy the
+ * necessary code for the reactive implementation like we did before, as point in time was introduced in Elasticsearch
+ * 7.12 after the license change.
+ *
+ * @author Peter-Josef Meisch
+ */
+@Disabled
+@ContextConfiguration(classes = ReactivePointInTimeERHLCIntegrationTests.Config.class)
+public class ReactivePointInTimeERHLCIntegrationTests extends ReactivePointInTimeIntegrationTests {
+
+	@Configuration
+	@Import({ ReactiveElasticsearchRestTemplateConfiguration.class })
+	static class Config {
+		@Bean
+		IndexNameProvider indexNameProvider() {
+			return new IndexNameProvider("reactive-point-in-time-es7");
+		}
+	}
+}