Add support for clear scroll to high level REST client

client/rest-high-level/src/main/java/org/elasticsearch/client/Request.java

@@ -33,6 +33,7 @@
 import org.elasticsearch.action.delete.DeleteRequest;
 import org.elasticsearch.action.get.GetRequest;
 import org.elasticsearch.action.index.IndexRequest;
+import org.elasticsearch.action.search.ClearScrollRequest;
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.action.search.SearchScrollRequest;
 import org.elasticsearch.action.support.ActiveShardCount;
@@ -344,6 +345,11 @@ static Request searchScroll(SearchScrollRequest searchScrollRequest) throws IOEx
         return new Request("GET", "/_search/scroll", Collections.emptyMap(), entity);
     }
 
+    static Request clearScroll(ClearScrollRequest clearScrollRequest) throws IOException {
+        HttpEntity entity = createEntity(clearScrollRequest, REQUEST_BODY_CONTENT_TYPE);
+        return new Request("DELETE", "/_search/scroll", Collections.emptyMap(), entity);
+    }
+
     private static HttpEntity createEntity(ToXContent toXContent, XContentType xContentType) throws IOException {
         BytesRef source = XContentHelper.toXContent(toXContent, xContentType, false).toBytesRef();
         return new ByteArrayEntity(source.bytes, source.offset, source.length, ContentType.create(xContentType.mediaType()));

client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java

@@ -36,6 +36,8 @@
 import org.elasticsearch.action.index.IndexResponse;
 import org.elasticsearch.action.main.MainRequest;
 import org.elasticsearch.action.main.MainResponse;
+import org.elasticsearch.action.search.ClearScrollRequest;
+import org.elasticsearch.action.search.ClearScrollResponse;
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.action.search.SearchScrollRequest;
@@ -347,6 +349,28 @@ public void searchScrollAsync(SearchScrollRequest searchScrollRequest, ActionLis
                 listener, emptySet(), headers);
     }
 
+    /**
+     * Clears one or more scroll ids using the Clear Scroll api
+     *
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-scroll.html#_clear_scroll_api">
+     * Clear Scroll API on elastic.co</a>
+     */
+    public ClearScrollResponse clearScroll(ClearScrollRequest clearScrollRequest, Header... headers) throws IOException {
+        return performRequestAndParseEntity(clearScrollRequest, Request::clearScroll, ClearScrollResponse::fromXContent,
+                emptySet(), headers);
+    }
+
+    /**
+     * Asynchronously clears one or more scroll ids using the Clear Scroll api
+     *
+     * See <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-scroll.html#_clear_scroll_api">
+     * Clear Scroll API on elastic.co</a>
+     */
+    public void clearScrollAsync(ClearScrollRequest clearScrollRequest, ActionListener<ClearScrollResponse> listener, Header... headers) {
+        performRequestAsyncAndParseEntity(clearScrollRequest, Request::clearScroll, ClearScrollResponse::fromXContent,
+                listener, emptySet(), headers);
+    }
+
     private <Req extends ActionRequest, Resp> Resp performRequestAndParseEntity(Req request,
                                                                             CheckedFunction<Req, Request, IOException> requestConverter,
                                                                             CheckedFunction<XContentParser, Resp, IOException> entityParser,

client/rest-high-level/src/test/java/org/elasticsearch/client/RequestTests.java

@@ -28,6 +28,7 @@
 import org.elasticsearch.action.delete.DeleteRequest;
 import org.elasticsearch.action.get.GetRequest;
 import org.elasticsearch.action.index.IndexRequest;
+import org.elasticsearch.action.search.ClearScrollRequest;
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.action.search.SearchScrollRequest;
 import org.elasticsearch.action.search.SearchType;
@@ -731,6 +732,21 @@ public void testSearchScroll() throws IOException {
         assertEquals("/_search/scroll", request.endpoint);
         assertEquals(0, request.params.size());
         assertToXContentBody(searchScrollRequest, request.entity);
+        assertEquals(Request.REQUEST_BODY_CONTENT_TYPE.mediaType(), request.entity.getContentType().getValue());
+    }
+
+    public void testClearScroll() throws IOException {
+        ClearScrollRequest clearScrollRequest = new ClearScrollRequest();
+        int numScrolls = randomIntBetween(1, 10);
+        for (int i = 0; i < numScrolls; i++) {
+            clearScrollRequest.addScrollId(randomAlphaOfLengthBetween(5, 10));
+        }
+        Request request = Request.clearScroll(clearScrollRequest);
+        assertEquals("DELETE", request.method);
+        assertEquals("/_search/scroll", request.endpoint);
+        assertEquals(0, request.params.size());
+        assertToXContentBody(clearScrollRequest, request.entity);
+        assertEquals(Request.REQUEST_BODY_CONTENT_TYPE.mediaType(), request.entity.getContentType().getValue());
     }
 
     private static void assertToXContentBody(ToXContent expectedBody, HttpEntity actualEntity) throws IOException {

client/rest-high-level/src/test/java/org/elasticsearch/client/RestHighLevelClientTests.java

@@ -42,6 +42,8 @@
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.main.MainRequest;
 import org.elasticsearch.action.main.MainResponse;
+import org.elasticsearch.action.search.ClearScrollRequest;
+import org.elasticsearch.action.search.ClearScrollResponse;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.action.search.SearchResponseSections;
 import org.elasticsearch.action.search.SearchScrollRequest;
@@ -161,6 +163,19 @@ public void testSearchScroll() throws IOException {
                 isNotNull(HttpEntity.class), argThat(new HeadersVarargMatcher(headers)));
     }
 
+    public void testClearScroll() throws IOException {
+        Header[] headers = randomHeaders(random(), "Header");
+        ClearScrollResponse mockClearScrollResponse = new ClearScrollResponse(randomBoolean(), randomIntBetween(0, Integer.MAX_VALUE));
+        mockResponse(mockClearScrollResponse);
+        ClearScrollRequest clearScrollRequest = new ClearScrollRequest();
+        clearScrollRequest.addScrollId(randomAlphaOfLengthBetween(5, 10));
+        ClearScrollResponse clearScrollResponse = restHighLevelClient.clearScroll(clearScrollRequest, headers);
+        assertEquals(mockClearScrollResponse.isSucceeded(), clearScrollResponse.isSucceeded());
+        assertEquals(mockClearScrollResponse.getNumFreed(), clearScrollResponse.getNumFreed());
+        verify(restClient).performRequest(eq("DELETE"), eq("/_search/scroll"), eq(Collections.emptyMap()),
+                isNotNull(HttpEntity.class), argThat(new HeadersVarargMatcher(headers)));
+    }
+
     private void mockResponse(ToXContent toXContent) throws IOException {
         Response response = mock(Response.class);
         ContentType contentType = ContentType.parse(Request.REQUEST_BODY_CONTENT_TYPE.mediaType());

client/rest-high-level/src/test/java/org/elasticsearch/client/SearchIT.java

@@ -19,11 +19,19 @@
 
 package org.elasticsearch.client;
 
+import org.apache.http.HttpEntity;
 import org.apache.http.entity.ContentType;
 import org.apache.http.entity.StringEntity;
+import org.apache.http.nio.entity.NStringEntity;
+import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ElasticsearchStatusException;
+import org.elasticsearch.action.search.ClearScrollRequest;
+import org.elasticsearch.action.search.ClearScrollResponse;
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.action.search.SearchScrollRequest;
+import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.index.query.MatchQueryBuilder;
 import org.elasticsearch.join.aggregations.Children;
 import org.elasticsearch.join.aggregations.ChildrenAggregationBuilder;
@@ -37,6 +45,7 @@
 import org.elasticsearch.search.aggregations.matrix.stats.MatrixStatsAggregationBuilder;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.builder.SearchSourceBuilder;
+import org.elasticsearch.search.sort.SortOrder;
 import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.SuggestBuilder;
 import org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder;
@@ -46,11 +55,14 @@
 import java.util.Arrays;
 import java.util.Collections;
 
+import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.hamcrest.Matchers.both;
+import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.either;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.lessThan;
 
 public class SearchIT extends ESRestHighLevelClientTestCase {
@@ -386,6 +398,63 @@ public void testSearchWithSuggest() throws IOException {
         }
     }
 
+    public void testSearchScroll() throws Exception {
+
+        for (int i = 0; i < 100; i++) {
+            XContentBuilder builder = jsonBuilder().startObject().field("field", i).endObject();
+            HttpEntity entity = new NStringEntity(builder.string(), ContentType.APPLICATION_JSON);
+            client().performRequest("PUT", "test/type1/" + Integer.toString(i), Collections.emptyMap(), entity);
+        }
+        client().performRequest("POST", "/test/_refresh");
+
+        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().size(35).sort("field", SortOrder.ASC);
+        SearchRequest searchRequest = new SearchRequest("test").scroll(TimeValue.timeValueMinutes(2)).source(searchSourceBuilder);
+        SearchResponse searchResponse = execute(searchRequest, highLevelClient()::search, highLevelClient()::searchAsync);
+
+        try {
+            long counter = 0;
+            assertSearchHeader(searchResponse);
+            assertThat(searchResponse.getHits().getTotalHits(), equalTo(100L));
+            assertThat(searchResponse.getHits().getHits().length, equalTo(35));
+            for (SearchHit hit : searchResponse.getHits()) {
+                assertThat(((Number) hit.getSortValues()[0]).longValue(), equalTo(counter++));
+            }
+
+            searchResponse = execute(new SearchScrollRequest(searchResponse.getScrollId()).scroll(TimeValue.timeValueMinutes(2)),
+                    highLevelClient()::searchScroll, highLevelClient()::searchScrollAsync);
+
+            assertThat(searchResponse.getHits().getTotalHits(), equalTo(100L));
+            assertThat(searchResponse.getHits().getHits().length, equalTo(35));
+            for (SearchHit hit : searchResponse.getHits()) {
+                assertEquals(counter++, ((Number) hit.getSortValues()[0]).longValue());
+            }
+
+            searchResponse = execute(new SearchScrollRequest(searchResponse.getScrollId()).scroll(TimeValue.timeValueMinutes(2)),
+                    highLevelClient()::searchScroll, highLevelClient()::searchScrollAsync);
+
+            assertThat(searchResponse.getHits().getTotalHits(), equalTo(100L));
+            assertThat(searchResponse.getHits().getHits().length, equalTo(30));
+            for (SearchHit hit : searchResponse.getHits()) {
+                assertEquals(counter++, ((Number) hit.getSortValues()[0]).longValue());
+            }
+        } finally {
+            ClearScrollRequest clearScrollRequest = new ClearScrollRequest();
+            clearScrollRequest.addScrollId(searchResponse.getScrollId());
+            ClearScrollResponse clearScrollResponse = execute(clearScrollRequest, highLevelClient()::clearScroll,
+                    highLevelClient()::clearScrollAsync);
+            assertThat(clearScrollResponse.getNumFreed(), greaterThan(0));
+            assertTrue(clearScrollResponse.isSucceeded());
+
+            SearchScrollRequest scrollRequest = new SearchScrollRequest(searchResponse.getScrollId()).scroll(TimeValue.timeValueMinutes(2));
+            ElasticsearchStatusException exception = expectThrows(ElasticsearchStatusException.class, () -> execute(scrollRequest,
+                    highLevelClient()::searchScroll, highLevelClient()::searchScrollAsync));
+            assertEquals(RestStatus.NOT_FOUND, exception.status());
+            assertThat(exception.getRootCause(), instanceOf(ElasticsearchException.class));
+            ElasticsearchException rootCause = (ElasticsearchException) exception.getRootCause();
+            assertThat(rootCause.getMessage(), containsString("No search context found for"));
+        }
+    }
+
     private static void assertSearchHeader(SearchResponse searchResponse) {
         assertThat(searchResponse.getTook().nanos(), greaterThanOrEqualTo(0L));
         assertEquals(0, searchResponse.getFailedShards());