Elasticsearch: Exclude types from V7 which deprecates them

Remove the use of the include_type_name parameter which started from V6.
Before this change, warnings related to the V7 usage of that parameter
showed in consoles.

More in [1] about the include_type_name parameter for Elasticsearch
6.x (warning), 7.x (deprecation), and 8.x (deprecated).

[1] https://www.elastic.co/guide/en/elasticsearch/reference/master/removal-of-types.html#_schedule_for_removal_of_mapping_types

Bug: Issue 10496
Change-Id: I6fe26e097a618d71a781dbebae621b6515d6822e

gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java

@@ -188,10 +188,15 @@ abstract class AbstractElasticIndex<K, V> implements Index<K, V> {
   }
 
   protected String getMappingsFor(String type, MappingProperties properties) {
-    JsonObject mappingType = new JsonObject();
-    mappingType.add(type, gson.toJsonTree(properties));
     JsonObject mappings = new JsonObject();
-    mappings.add(MAPPINGS, gson.toJsonTree(mappingType));
+
+    if (client.adapter().omitType()) {
+      mappings.add(MAPPINGS, gson.toJsonTree(properties));
+    } else {
+      JsonObject mappingType = new JsonObject();
+      mappingType.add(type, gson.toJsonTree(properties));
+      mappings.add(MAPPINGS, gson.toJsonTree(mappingType));
+    }
     return gson.toJson(mappings);
   }
 
@@ -229,11 +234,12 @@ abstract class AbstractElasticIndex<K, V> implements Index<K, V> {
 
   protected String getURI(String type, String request) throws UnsupportedEncodingException {
     String encodedIndexName = URLEncoder.encode(indexName, UTF_8.toString());
-    if (SEARCH.equals(request) && client.adapter().omitTypeFromSearch()) {
+    if (SEARCH.equals(request) && client.adapter().omitType()) {
       return encodedIndexName + "/" + request;
     }
-    String encodedType = URLEncoder.encode(type, UTF_8.toString());
-    return encodedIndexName + "/" + encodedType + "/" + request;
+    String encodedTypeIfAny =
+        client.adapter().omitType() ? "" : "/" + URLEncoder.encode(type, UTF_8.toString());
+    return encodedIndexName + encodedTypeIfAny + "/" + request;
   }
 
   protected Response postRequest(String uri, Object payload) throws IOException {

gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java

@@ -141,7 +141,7 @@ class ElasticChangeIndex extends AbstractElasticIndex<Change.Id, ChangeData>
     BulkRequest bulk =
         new IndexRequest(getId(cd), indexName, adapter.getType(insertIndex), adapter)
             .add(new UpdateRequest<>(schema, cd));
-    if (!adapter.usePostV5Type()) {
+    if (adapter.deleteToReplace()) {
       bulk.add(new DeleteRequest(cd.getId().toString(), indexName, deleteIndex, adapter));
     }
 
@@ -160,17 +160,19 @@ class ElasticChangeIndex extends AbstractElasticIndex<Change.Id, ChangeData>
       throws QueryParseException {
     Set<Change.Status> statuses = ChangeIndexRewriter.getPossibleStatus(p);
     List<String> indexes = Lists.newArrayListWithCapacity(2);
-    if (client.adapter().usePostV5Type()) {
-      if (!Sets.intersection(statuses, OPEN_STATUSES).isEmpty()
-          || !Sets.intersection(statuses, CLOSED_STATUSES).isEmpty()) {
-        indexes.add(ElasticQueryAdapter.POST_V5_TYPE);
-      }
-    } else {
-      if (!Sets.intersection(statuses, OPEN_STATUSES).isEmpty()) {
-        indexes.add(OPEN_CHANGES);
-      }
-      if (!Sets.intersection(statuses, CLOSED_STATUSES).isEmpty()) {
-        indexes.add(CLOSED_CHANGES);
+    if (!client.adapter().omitType()) {
+      if (client.adapter().useV6Type()) {
+        if (!Sets.intersection(statuses, OPEN_STATUSES).isEmpty()
+            || !Sets.intersection(statuses, CLOSED_STATUSES).isEmpty()) {
+          indexes.add(ElasticQueryAdapter.V6_TYPE);
+        }
+      } else {
+        if (!Sets.intersection(statuses, OPEN_STATUSES).isEmpty()) {
+          indexes.add(OPEN_CHANGES);
+        }
+        if (!Sets.intersection(statuses, CLOSED_STATUSES).isEmpty()) {
+          indexes.add(CLOSED_CHANGES);
+        }
       }
     }
     return new QuerySource(indexes, p, opts);
@@ -178,16 +180,16 @@ class ElasticChangeIndex extends AbstractElasticIndex<Change.Id, ChangeData>
 
   @Override
   protected String getDeleteActions(Id c) {
-    if (client.adapter().usePostV5Type()) {
-      return delete(ElasticQueryAdapter.POST_V5_TYPE, c);
+    if (!client.adapter().useV5Type()) {
+      return delete(client.adapter().getType(), c);
     }
     return delete(OPEN_CHANGES, c) + delete(CLOSED_CHANGES, c);
   }
 
   @Override
   protected String getMappings() {
-    if (client.adapter().usePostV5Type()) {
-      return getMappingsFor(ElasticQueryAdapter.POST_V5_TYPE, mapping.changes);
+    if (!client.adapter().useV5Type()) {
+      return getMappingsFor(client.adapter().getType(), mapping.changes);
     }
     return gson.toJson(ImmutableMap.of(MAPPINGS, mapping));
   }

gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java

@@ -17,11 +17,12 @@ package com.google.gerrit.elasticsearch;
 import com.google.gson.JsonObject;
 
 public class ElasticQueryAdapter {
-  static final String POST_V5_TYPE = "_doc";
+  static final String V6_TYPE = "_doc";
 
   private final boolean ignoreUnmapped;
-  private final boolean usePostV5Type;
-  private final boolean omitTypeFromSearch;
+  private final boolean useV5Type;
+  private final boolean useV6Type;
+  private final boolean omitType;
 
   private final String searchFilteringName;
   private final String indicesExistParam;
@@ -33,15 +34,16 @@ public class ElasticQueryAdapter {
 
   ElasticQueryAdapter(ElasticVersion version) {
     this.ignoreUnmapped = false;
-    this.usePostV5Type = version.isV6OrLater();
-    this.omitTypeFromSearch = version.isV7OrLater();
+    this.useV5Type = !version.isV6OrLater();
+    this.useV6Type = version.isV6();
+    this.omitType = version.isV7OrLater();
     this.versionDiscoveryUrl = version.isV6OrLater() ? "/%s*" : "/%s*/_aliases";
     this.searchFilteringName = "_source";
     this.indicesExistParam = "?allow_no_indices=false";
     this.exactFieldType = "keyword";
     this.stringFieldType = "text";
     this.indexProperty = "true";
-    this.includeTypeNameParam = version.isV7OrLater() ? "?include_type_name=true" : "";
+    this.includeTypeNameParam = version.isV6() ? "?include_type_name=true" : "";
   }
 
   void setIgnoreUnmapped(JsonObject properties) {
@@ -51,7 +53,7 @@ public class ElasticQueryAdapter {
   }
 
   public void setType(JsonObject properties, String type) {
-    if (!usePostV5Type) {
+    if (useV5Type) {
       properties.addProperty("_type", type);
     }
   }
@@ -76,16 +78,31 @@ public class ElasticQueryAdapter {
     return indexProperty;
   }
 
-  boolean usePostV5Type() {
-    return usePostV5Type;
+  boolean deleteToReplace() {
+    return useV5Type;
   }
 
-  boolean omitTypeFromSearch() {
-    return omitTypeFromSearch;
+  boolean useV5Type() {
+    return useV5Type;
+  }
+
+  boolean useV6Type() {
+    return useV6Type;
+  }
+
+  boolean omitType() {
+    return omitType;
+  }
+
+  String getType() {
+    return getType("");
   }
 
   String getType(String type) {
-    return usePostV5Type() ? POST_V5_TYPE : type;
+    if (useV6Type()) {
+      return V6_TYPE;
+    }
+    return useV5Type() ? type : "";
   }
 
   String getVersionDiscoveryUrl(String name) {

gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java

@@ -58,6 +58,10 @@ public enum ElasticVersion {
     return Joiner.on(", ").join(ElasticVersion.values());
   }
 
+  public boolean isV6() {
+    return getMajor() == 6;
+  }
+
   public boolean isV6OrLater() {
     return isAtLeastVersion(6);
   }
@@ -67,7 +71,11 @@ public enum ElasticVersion {
   }
 
   private boolean isAtLeastVersion(int v) {
-    return Integer.valueOf(version.split("\\.")[0]) >= v;
+    return getMajor() >= v;
+  }
+
+  private Integer getMajor() {
+    return Integer.valueOf(version.split("\\.")[0]);
   }
 
   @Override