Remove `flatSettings` support from request classes (#29560)

As part of adding support for new API to the high-level REST client,
we added support for the `flat_settings` parameter to some of our
request classes. We added documentation that such flag is only ever
read by the high-level REST client, but the truth is that it doesn't
do anything given that settings are always parsed back into a `Settings`
object, no matter whether they are returned in a flat format or not.

It was a mistake to add support for this flag in the context of the
high-level REST client, hence this commit removes it.

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

@@ -572,7 +572,6 @@ public final class Request {
 
     static Request clusterPutSettings(ClusterUpdateSettingsRequest clusterUpdateSettingsRequest) throws IOException {
         Params parameters = Params.builder();
-        parameters.withFlatSettings(clusterUpdateSettingsRequest.flatSettings());
         parameters.withTimeout(clusterUpdateSettingsRequest.timeout());
         parameters.withMasterTimeout(clusterUpdateSettingsRequest.masterNodeTimeout());
         HttpEntity entity = createEntity(clusterUpdateSettingsRequest, REQUEST_BODY_CONTENT_TYPE);
@@ -603,7 +602,6 @@ public final class Request {
         params.withLocal(request.local());
         params.withHuman(request.humanReadable());
         params.withIndicesOptions(request.indicesOptions());
-        params.withFlatSettings(request.flatSettings());
         params.withIncludeDefaults(request.includeDefaults());
         return new Request(HttpHead.METHOD_NAME, endpoint, params.getParams(), null);
     }
@@ -613,7 +611,6 @@ public final class Request {
         parameters.withTimeout(updateSettingsRequest.timeout());
         parameters.withMasterTimeout(updateSettingsRequest.masterNodeTimeout());
         parameters.withIndicesOptions(updateSettingsRequest.indicesOptions());
-        parameters.withFlatSettings(updateSettingsRequest.flatSettings());
         parameters.withPreserveExisting(updateSettingsRequest.isPreserveExisting());
 
         String[] indices = updateSettingsRequest.indices() == null ? Strings.EMPTY_ARRAY : updateSettingsRequest.indices();

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

@@ -272,7 +272,6 @@ public class RequestTests extends ESTestCase {
         Map<String, String> expectedParams = new HashMap<>();
         setRandomIndicesOptions(getIndexRequest::indicesOptions, getIndexRequest::indicesOptions, expectedParams);
         setRandomLocal(getIndexRequest, expectedParams);
-        setRandomFlatSettings(getIndexRequest::flatSettings, expectedParams);
         setRandomHumanReadable(getIndexRequest, expectedParams);
         setRandomIncludeDefaults(getIndexRequest, expectedParams);
 
@@ -1292,7 +1291,6 @@ public class RequestTests extends ESTestCase {
     public void testClusterPutSettings() throws IOException {
         ClusterUpdateSettingsRequest request = new ClusterUpdateSettingsRequest();
         Map<String, String> expectedParams = new HashMap<>();
-        setRandomFlatSettings(request::flatSettings, expectedParams);
         setRandomMasterTimeout(request, expectedParams);
         setRandomTimeout(request::timeout, AcknowledgedRequest.DEFAULT_ACK_TIMEOUT, expectedParams);
 
@@ -1344,7 +1342,6 @@ public class RequestTests extends ESTestCase {
         String[] indices = randomBoolean() ? null : randomIndicesNames(0, 2);
         UpdateSettingsRequest updateSettingsRequest = new UpdateSettingsRequest(indices);
         Map<String, String> expectedParams = new HashMap<>();
-        setRandomFlatSettings(updateSettingsRequest::flatSettings, expectedParams);
         setRandomMasterTimeout(updateSettingsRequest, expectedParams);
         setRandomTimeout(updateSettingsRequest::timeout, AcknowledgedRequest.DEFAULT_ACK_TIMEOUT, expectedParams);
         setRandomIndicesOptions(updateSettingsRequest::indicesOptions, updateSettingsRequest::indicesOptions, expectedParams);
@@ -1627,16 +1624,6 @@ public class RequestTests extends ESTestCase {
         }
     }
 
-    private static void setRandomFlatSettings(Consumer<Boolean> setter, Map<String, String> expectedParams) {
-        if (randomBoolean()) {
-            boolean flatSettings = randomBoolean();
-            setter.accept(flatSettings);
-            if (flatSettings) {
-                expectedParams.put("flat_settings", String.valueOf(flatSettings));
-            }
-        }
-    }
-
     private static void setRandomMasterTimeout(MasterNodeRequest<?> request, Map<String, String> expectedParams) {
         if (randomBoolean()) {
             String masterTimeout = randomTimeValue();

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

@@ -124,10 +124,6 @@ public class ClusterClientDocumentationIT extends ESRestHighLevelClientTestCase
         request.masterNodeTimeout("1m"); // <2>
         // end::put-settings-request-masterTimeout
 
-        // tag::put-settings-request-flat-settings
-        request.flatSettings(true); // <1>
-        // end::put-settings-request-flat-settings
-
         // tag::put-settings-execute
         ClusterUpdateSettingsResponse response = client.cluster().putSettings(request);
         // end::put-settings-execute

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

@@ -58,7 +58,6 @@ import org.elasticsearch.action.support.DefaultShardOperationFailedException;
 import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.client.ESRestHighLevelClientTestCase;
 import org.elasticsearch.client.RestHighLevelClient;
-import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.ByteSizeUnit;
 import org.elasticsearch.common.unit.ByteSizeValue;
@@ -114,8 +113,7 @@ public class IndicesClientDocumentationIT extends ESRestHighLevelClientTestCase
             request.local(false); // <1>
             request.humanReadable(true); // <2>
             request.includeDefaults(false); // <3>
-            request.flatSettings(false); // <4>
-            request.indicesOptions(indicesOptions); // <5>
+            request.indicesOptions(indicesOptions); // <4>
             // end::indices-exists-request-optionals
 
             // tag::indices-exists-response
@@ -1433,9 +1431,6 @@ public class IndicesClientDocumentationIT extends ESRestHighLevelClientTestCase
             // end::put-settings-settings-source
         }
 
-        // tag::put-settings-request-flat-settings
-        request.flatSettings(true); // <1>
-        // end::put-settings-request-flat-settings
         // tag::put-settings-request-preserveExisting
         request.setPreserveExisting(false); // <1>
         // end::put-settings-request-preserveExisting

docs/java-rest/high-level/cluster/put_settings.asciidoc

@@ -54,13 +54,6 @@ include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[put-settings-setti
 ==== Optional Arguments
 The following arguments can optionally be provided:
 
-["source","java",subs="attributes,callouts,macros"]
---------------------------------------------------
-include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[put-settings-request-flat-settings]
---------------------------------------------------
-<1> Whether the updated settings returned in the `ClusterUpdateSettings` should
-be in a flat format
-
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------
 include-tagged::{doc-tests}/ClusterClientDocumentationIT.java[put-settings-request-timeout]

docs/java-rest/high-level/indices/indices_exists.asciidoc

@@ -23,8 +23,7 @@ include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[indices-exists-req
 <1> Whether to return local information or retrieve the state from master node
 <2> Return result in a format suitable for humans
 <3> Whether to return all default setting for each of the indices
-<4> Return settings in flat format
-<5> Controls how unavailable indices are resolved and how wildcard expressions are expanded
+<4> Controls how unavailable indices are resolved and how wildcard expressions are expanded
 
 [[java-rest-high-indices-sync]]
 ==== Synchronous Execution

docs/java-rest/high-level/indices/put_settings.asciidoc

@@ -55,13 +55,6 @@ include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[put-settings-setti
 ==== Optional Arguments
 The following arguments can optionally be provided:
 
-["source","java",subs="attributes,callouts,macros"]
---------------------------------------------------
-include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[put-settings-request-flat-settings]
---------------------------------------------------
-<1> Whether the updated settings returned in the `UpdateSettings` should
-be in a flat format
-
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------
 include-tagged::{doc-tests}/IndicesClientDocumentationIT.java[put-settings-request-preserveExisting]

server/src/main/java/org/elasticsearch/action/admin/cluster/settings/ClusterUpdateSettingsRequest.java

@@ -58,7 +58,6 @@ public class ClusterUpdateSettingsRequest extends AcknowledgedRequest<ClusterUpd
         PARSER.declareObject((r, t) -> r.transientSettings = t, (p, c) -> Settings.fromXContent(p), TRANSIENT);
     }
 
-    private boolean flatSettings = false;
     private Settings transientSettings = EMPTY_SETTINGS;
     private Settings persistentSettings = EMPTY_SETTINGS;
 
@@ -74,29 +73,6 @@ public class ClusterUpdateSettingsRequest extends AcknowledgedRequest<ClusterUpd
         return validationException;
     }
 
-    /**
-     * Sets the value of "flat_settings".
-     * Used only by the high-level REST client.
-     *
-     * @param flatSettings
-     *            value of "flat_settings" flag to be set
-     * @return this request
-     */
-    public ClusterUpdateSettingsRequest flatSettings(boolean flatSettings) {
-        this.flatSettings = flatSettings;
-        return this;
-    }
-
-    /**
-     * Return settings in flat format.
-     * Used only by the high-level REST client.
-     *
-     * @return <code>true</code> if settings need to be returned in flat format; <code>false</code> otherwise.
-     */
-    public boolean flatSettings() {
-        return flatSettings;
-    }
-
     public Settings transientSettings() {
         return transientSettings;
     }

server/src/main/java/org/elasticsearch/action/admin/indices/get/GetIndexRequest.java

@@ -66,7 +66,6 @@ public class GetIndexRequest extends ClusterInfoRequest<GetIndexRequest> {
     private static final Feature[] DEFAULT_FEATURES = new Feature[] { Feature.ALIASES, Feature.MAPPINGS, Feature.SETTINGS };
     private Feature[] features = DEFAULT_FEATURES;
     private boolean humanReadable = false;
-    private transient boolean flatSettings = false;
     private transient boolean includeDefaults = false;
 
     public GetIndexRequest() {
@@ -118,28 +117,6 @@ public class GetIndexRequest extends ClusterInfoRequest<GetIndexRequest> {
         return humanReadable;
     }
 
-    /**
-     * Sets the value of "flat_settings".
-     * Used only by the high-level REST client.
-     * 
-     * @param flatSettings value of "flat_settings" flag to be set
-     * @return this request
-     */
-    public GetIndexRequest flatSettings(boolean flatSettings) {
-        this.flatSettings = flatSettings;
-        return this;
-    }
-
-    /**
-     * Return settings in flat format.
-     * Used only by the high-level REST client.
-     * 
-     * @return <code>true</code> if settings need to be returned in flat format; <code>false</code> otherwise.
-     */
-    public boolean flatSettings() {
-        return flatSettings;
-    }
-
     /**
      * Sets the value of "include_defaults".
      * Used only by the high-level REST client.

server/src/main/java/org/elasticsearch/action/admin/indices/settings/put/UpdateSettingsRequest.java

@@ -55,7 +55,6 @@ public class UpdateSettingsRequest extends AcknowledgedRequest<UpdateSettingsReq
     private IndicesOptions indicesOptions = IndicesOptions.fromOptions(false, false, true, true);
     private Settings settings = EMPTY_SETTINGS;
     private boolean preserveExisting = false;
-    private boolean flatSettings = false;
 
     public UpdateSettingsRequest() {
     }
@@ -75,29 +74,6 @@ public class UpdateSettingsRequest extends AcknowledgedRequest<UpdateSettingsReq
         this.settings = settings;
     }
 
-    /**
-     * Sets the value of "flat_settings".
-     * Used only by the high-level REST client.
-     * 
-     * @param flatSettings
-     *            value of "flat_settings" flag to be set
-     * @return this request
-     */
-    public UpdateSettingsRequest flatSettings(boolean flatSettings) {
-        this.flatSettings = flatSettings;
-        return this;
-    }
-
-    /**
-     * Return settings in flat format.
-     * Used only by the high-level REST client.
-     * 
-     * @return <code>true</code> if settings need to be returned in flat format; <code>false</code> otherwise.
-     */
-    public boolean flatSettings() {
-        return flatSettings;
-    }
-
     @Override
     public ActionRequestValidationException validate() {
         ActionRequestValidationException validationException = null;

server/src/test/java/org/elasticsearch/action/admin/indices/settings/put/UpdateSettingsRequestStreamableTests.java

@@ -67,7 +67,6 @@ public class UpdateSettingsRequestStreamableTests extends AbstractStreamableTest
         request.timeout(randomTimeValue());
         request.indicesOptions(IndicesOptions.fromOptions(randomBoolean(), randomBoolean(), randomBoolean(), randomBoolean()));
         request.setPreserveExisting(randomBoolean());
-        request.flatSettings(randomBoolean());
         return request;
     }
 
@@ -77,7 +76,6 @@ public class UpdateSettingsRequestStreamableTests extends AbstractStreamableTest
         result.timeout(request.timeout());
         result.indicesOptions(request.indicesOptions());
         result.setPreserveExisting(request.isPreserveExisting());
-        result.flatSettings(request.flatSettings());
         return result;
     }