Remove dead branches for v7 REST API (elastic#114850)

In v9 the `getRestApiVersion()` method on `RestRequest`,
`XContentBuilder` and `XContentParser` can never return `V_7`, so we can
replace all the expressions of the form `$x$.getRestApiVersion() == V_7`
with `false`. This commit does that, and then refactors away the
resulting dead code using (largely) automated transformations.

Author: DaveCTurner

modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestMultiSearchTemplateAction.java

@@ -11,7 +11,6 @@
 
 import org.elasticsearch.client.internal.node.NodeClient;
 import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.Scope;
@@ -65,10 +64,6 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
      * Parses a {@link RestRequest} body and returns a {@link MultiSearchTemplateRequest}
      */
     public static MultiSearchTemplateRequest parseRequest(RestRequest restRequest, boolean allowExplicitIndex) throws IOException {
-        if (restRequest.getRestApiVersion() == RestApiVersion.V_7 && restRequest.hasParam("type")) {
-            restRequest.param("type");
-        }
-
         MultiSearchTemplateRequest multiRequest = new MultiSearchTemplateRequest();
         if (restRequest.hasParam("max_concurrent_searches")) {
             multiRequest.maxConcurrentSearchRequests(restRequest.paramAsInt("max_concurrent_searches", 0));

modules/percolator/src/main/java/org/elasticsearch/percolator/PercolateQueryBuilder.java

@@ -54,7 +54,6 @@
 import org.elasticsearch.index.fielddata.IndexFieldDataCache;
 import org.elasticsearch.index.mapper.LuceneDocument;
 import org.elasticsearch.index.mapper.MappedFieldType;
-import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.mapper.NestedLookup;
 import org.elasticsearch.index.mapper.ParsedDocument;
 import org.elasticsearch.index.mapper.SourceToParse;
@@ -312,9 +311,6 @@ protected void doXContent(XContentBuilder builder, Params params) throws IOExcep
             if (indexedDocumentIndex != null) {
                 builder.field(INDEXED_DOCUMENT_FIELD_INDEX.getPreferredName(), indexedDocumentIndex);
             }
-            if (builder.getRestApiVersion() == RestApiVersion.V_7) {
-                builder.field(INDEXED_DOCUMENT_FIELD_TYPE.getPreferredName(), MapperService.SINGLE_MAPPING_NAME);
-            }
             if (indexedDocumentId != null) {
                 builder.field(INDEXED_DOCUMENT_FIELD_ID.getPreferredName(), indexedDocumentId);
             }

modules/reindex/src/main/java/org/elasticsearch/reindex/AbstractBulkByQueryRestHandler.java

@@ -14,7 +14,6 @@
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
 import org.elasticsearch.common.xcontent.XContentHelper;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.features.NodeFeature;
 import org.elasticsearch.index.reindex.AbstractBulkByScrollRequest;
 import org.elasticsearch.index.reindex.BulkByScrollResponse;
@@ -28,7 +27,6 @@
 import java.io.IOException;
 import java.util.Map;
 import java.util.function.Consumer;
-import java.util.function.IntConsumer;
 import java.util.function.Predicate;
 
 /**
@@ -54,10 +52,7 @@ protected void parseInternalRequest(
         SearchRequest searchRequest = internal.getSearchRequest();
 
         try (XContentParser parser = extractRequestSpecificFields(restRequest, bodyConsumers)) {
-            IntConsumer sizeConsumer = restRequest.getRestApiVersion() == RestApiVersion.V_7
-                ? size -> setMaxDocsFromSearchSize(internal, size)
-                : size -> failOnSizeSpecified();
-            RestSearchAction.parseSearchRequest(searchRequest, restRequest, parser, clusterSupportsFeature, sizeConsumer);
+            RestSearchAction.parseSearchRequest(searchRequest, restRequest, parser, clusterSupportsFeature, size -> failOnSizeSpecified());
         }
 
         searchRequest.source().size(restRequest.paramAsInt("scroll_size", searchRequest.source().size()));

modules/reindex/src/main/java/org/elasticsearch/reindex/RestUpdateByQueryAction.java

@@ -10,7 +10,6 @@
 package org.elasticsearch.reindex;
 
 import org.elasticsearch.client.internal.node.NodeClient;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.features.NodeFeature;
 import org.elasticsearch.index.reindex.UpdateByQueryAction;
 import org.elasticsearch.index.reindex.UpdateByQueryRequest;
@@ -55,9 +54,6 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
 
     @Override
     protected UpdateByQueryRequest buildRequest(RestRequest request) throws IOException {
-        if (request.getRestApiVersion() == RestApiVersion.V_7 && request.hasParam("type")) {
-            request.param("type");
-        }
         /*
          * Passing the search request through UpdateByQueryRequest first allows
          * it to set its own defaults which differ from SearchRequest's

server/src/main/java/org/elasticsearch/action/DocWriteResponse.java

@@ -18,7 +18,6 @@
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
 import org.elasticsearch.core.Nullable;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.seqno.SequenceNumbers;
@@ -298,9 +297,6 @@ public XContentBuilder innerToXContent(XContentBuilder builder, Params params) t
             builder.field(_SEQ_NO, getSeqNo());
             builder.field(_PRIMARY_TERM, getPrimaryTerm());
         }
-        if (builder.getRestApiVersion() == RestApiVersion.V_7) {
-            builder.field(MapperService.TYPE_FIELD_NAME, MapperService.SINGLE_MAPPING_NAME);
-        }
         return builder;
     }
 

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

@@ -19,7 +19,6 @@
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.ChunkedToXContentObject;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.xcontent.ToXContent;
 
@@ -30,9 +29,6 @@
 import java.util.Map;
 import java.util.Objects;
 
-import static org.elasticsearch.rest.BaseRestHandler.DEFAULT_INCLUDE_TYPE_NAME_POLICY;
-import static org.elasticsearch.rest.BaseRestHandler.INCLUDE_TYPE_NAME_PARAMETER;
-
 /**
  * A response for a get index action.
  */
@@ -200,14 +196,7 @@ public Iterator<? extends ToXContent> toXContentChunked(ToXContent.Params ignore
                 if (indexMappings == null) {
                     builder.startObject("mappings").endObject();
                 } else {
-                    if (builder.getRestApiVersion() == RestApiVersion.V_7
-                        && params.paramAsBoolean(INCLUDE_TYPE_NAME_PARAMETER, DEFAULT_INCLUDE_TYPE_NAME_POLICY)) {
-                        builder.startObject("mappings");
-                        builder.field(MapperService.SINGLE_MAPPING_NAME, indexMappings.sourceAsMap());
-                        builder.endObject();
-                    } else {
-                        builder.field("mappings", indexMappings.sourceAsMap());
-                    }
+                    builder.field("mappings", indexMappings.sourceAsMap());
                 }
 
                 builder.startObject("settings");

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

@@ -15,10 +15,8 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentHelper;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.index.mapper.Mapper;
 import org.elasticsearch.index.mapper.MapperService;
-import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.xcontent.ParseField;
 import org.elasticsearch.xcontent.ToXContentFragment;
 import org.elasticsearch.xcontent.ToXContentObject;
@@ -31,8 +29,6 @@
 import java.util.Map;
 import java.util.Objects;
 
-import static org.elasticsearch.rest.BaseRestHandler.DEFAULT_INCLUDE_TYPE_NAME_POLICY;
-
 /**
  * Response object for {@link GetFieldMappingsRequest} API
  *
@@ -91,16 +87,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.startObject(indexEntry.getKey());
             builder.startObject(MAPPINGS.getPreferredName());
             if (indexEntry.getValue() != null) {
-                if (builder.getRestApiVersion() == RestApiVersion.V_7
-                    && params.paramAsBoolean(BaseRestHandler.INCLUDE_TYPE_NAME_PARAMETER, DEFAULT_INCLUDE_TYPE_NAME_POLICY)) {
-                    if (indexEntry.getValue().size() > 0) {
-                        builder.startObject(MapperService.SINGLE_MAPPING_NAME);
-                        addFieldMappingsToBuilder(builder, params, indexEntry.getValue());
-                        builder.endObject();
-                    }
-                } else {
-                    addFieldMappingsToBuilder(builder, params, indexEntry.getValue());
-                }
+                addFieldMappingsToBuilder(builder, params, indexEntry.getValue());
             }
 
             builder.endObject();

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

@@ -17,7 +17,6 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ChunkedToXContentObject;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.xcontent.ParseField;
 import org.elasticsearch.xcontent.ToXContent;
@@ -26,9 +25,6 @@
 import java.util.Iterator;
 import java.util.Map;
 
-import static org.elasticsearch.rest.BaseRestHandler.DEFAULT_INCLUDE_TYPE_NAME_POLICY;
-import static org.elasticsearch.rest.BaseRestHandler.INCLUDE_TYPE_NAME_PARAMETER;
-
 public class GetMappingsResponse extends ActionResponse implements ChunkedToXContentObject {
 
     private static final ParseField MAPPINGS = new ParseField("mappings");
@@ -73,16 +69,7 @@ public Iterator<ToXContent> toXContentChunked(ToXContent.Params outerParams) {
             Iterators.single((b, p) -> b.startObject()),
             Iterators.map(getMappings().entrySet().iterator(), indexEntry -> (builder, params) -> {
                 builder.startObject(indexEntry.getKey());
-                boolean includeTypeName = params.paramAsBoolean(INCLUDE_TYPE_NAME_PARAMETER, DEFAULT_INCLUDE_TYPE_NAME_POLICY);
-                if (builder.getRestApiVersion() == RestApiVersion.V_7 && includeTypeName && indexEntry.getValue() != null) {
-                    builder.startObject(MAPPINGS.getPreferredName());
-
-                    if (indexEntry.getValue() != MappingMetadata.EMPTY_MAPPINGS) {
-                        builder.field(MapperService.SINGLE_MAPPING_NAME, indexEntry.getValue().sourceAsMap());
-                    }
-                    builder.endObject();
-
-                } else if (indexEntry.getValue() != null) {
+                if (indexEntry.getValue() != null) {
                     builder.field(MAPPINGS.getPreferredName(), indexEntry.getValue().sourceAsMap());
                 } else {
                     builder.startObject(MAPPINGS.getPreferredName()).endObject();

server/src/main/java/org/elasticsearch/action/admin/indices/rollover/RolloverRequest.java

@@ -42,7 +42,7 @@
  */
 public class RolloverRequest extends AcknowledgedRequest<RolloverRequest> implements IndicesRequest {
 
-    private static final ObjectParser<RolloverRequest, Boolean> PARSER = new ObjectParser<>("rollover");
+    private static final ObjectParser<RolloverRequest, Void> PARSER = new ObjectParser<>("rollover");
 
     private static final ParseField CONDITIONS = new ParseField("conditions");
 
@@ -57,27 +57,18 @@ public class RolloverRequest extends AcknowledgedRequest<RolloverRequest> implem
             CreateIndexRequest.SETTINGS,
             ObjectParser.ValueType.OBJECT
         );
-        PARSER.declareField((parser, request, includeTypeName) -> {
-            if (includeTypeName) {
-                // expecting one type only
-                for (Map.Entry<String, Object> mappingsEntry : parser.map().entrySet()) {
-                    @SuppressWarnings("unchecked")
-                    final Map<String, Object> value = (Map<String, Object>) mappingsEntry.getValue();
-                    request.createIndexRequest.mapping(value);
-                }
-            } else {
-                // a type is not included, add a dummy _doc type
-                Map<String, Object> mappings = parser.map();
-                if (MapperService.isMappingSourceTyped(MapperService.SINGLE_MAPPING_NAME, mappings)) {
-                    throw new IllegalArgumentException(
-                        "The mapping definition cannot be nested under a type "
-                            + "["
-                            + MapperService.SINGLE_MAPPING_NAME
-                            + "] unless include_type_name is set to true."
-                    );
-                }
-                request.createIndexRequest.mapping(mappings);
+        PARSER.declareField((parser, request, context) -> {
+            // a type is not included, add a dummy _doc type
+            Map<String, Object> mappings = parser.map();
+            if (MapperService.isMappingSourceTyped(MapperService.SINGLE_MAPPING_NAME, mappings)) {
+                throw new IllegalArgumentException(
+                    "The mapping definition cannot be nested under a type "
+                        + "["
+                        + MapperService.SINGLE_MAPPING_NAME
+                        + "] unless include_type_name is set to true."
+                );
             }
+            request.createIndexRequest.mapping(mappings);
         }, CreateIndexRequest.MAPPINGS.forRestApiVersion(RestApiVersion.equalTo(RestApiVersion.V_7)), ObjectParser.ValueType.OBJECT);
         PARSER.declareField((parser, request, context) -> {
             // a type is not included, add a dummy _doc type
@@ -290,8 +281,8 @@ public CreateIndexRequest getCreateIndexRequest() {
     }
 
     // param isTypeIncluded decides how mappings should be parsed from XContent
-    public void fromXContent(boolean isTypeIncluded, XContentParser parser) throws IOException {
-        PARSER.parse(parser, this, isTypeIncluded);
+    public void fromXContent(XContentParser parser) throws IOException {
+        PARSER.parse(parser, this, null);
     }
 
     @Override

server/src/main/java/org/elasticsearch/action/admin/indices/segments/IndicesSegmentResponse.java

@@ -16,10 +16,8 @@
 import org.elasticsearch.action.support.broadcast.ChunkedBroadcastResponse;
 import org.elasticsearch.common.collect.Iterators;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.xcontent.ChunkedToXContentHelper;
 import org.elasticsearch.core.Nullable;
-import org.elasticsearch.core.RestApiVersion;
 import org.elasticsearch.xcontent.ToXContent;
 
 import java.io.IOException;
@@ -120,9 +118,6 @@ protected Iterator<ToXContent> customXContentChunks(ToXContent.Params params) {
                                                 builder.field(Fields.NUM_DOCS, segment.getNumDocs());
                                                 builder.field(Fields.DELETED_DOCS, segment.getDeletedDocs());
                                                 builder.humanReadableField(Fields.SIZE_IN_BYTES, Fields.SIZE, segment.getSize());
-                                                if (builder.getRestApiVersion() == RestApiVersion.V_7) {
-                                                    builder.humanReadableField(Fields.MEMORY_IN_BYTES, Fields.MEMORY, ByteSizeValue.ZERO);
-                                                }
                                                 builder.field(Fields.COMMITTED, segment.isCommitted());
                                                 builder.field(Fields.SEARCH, segment.isSearch());
                                                 if (segment.getVersion() != null) {