Expose index.change.mergeable in ServerInfo

This commit exposes indexMergeable in ServerInfo to allow the UI to hide
the 'is:mergeable' operator conditionally if the Gerrit instance does
not support indexing the 'mergeable' bit.

Change-Id: I1959244ff0069d0368bbee1fc8a527c3f3b2b0b2

Documentation/rest-api-config.txt

@@ -1572,6 +1572,21 @@ configuration parameter] that controls whether the mergeability bit in
 link:rest-api-changes.html#change-info[ChangeInfo] will never be set.
 |=============================
 
+[[change-index-config-info]]
+=== ChangeIndexConfigInfo
+The `ChangeIndexConfigInfo` entity contains information about Gerrit
+configuration from the link:config-gerrit.html#index.change[index.change]
+section.
+
+[options="header",cols="1,^1,5"]
+|=============================
+|Field Name           ||Description
+|`index_mergeable`        |not set if `false`|
+Value of the link:config-gerrit.html#index.change.indexMergeable[
+configuration parameter] that controls whether the mergeability bit is
+indexed (hence queryable using `is:mergeable`).
+|=============================
+
 [[check-account-external-ids-input]]
 === CheckAccountExternalIdsInput
 The `CheckAccountExternalIdsInput` entity contains input for the
@@ -1821,6 +1836,21 @@ Whether to enable the web UI for editing GPG keys.
 link:config-gerrit.html#gerrit.reportBugUrl[URL to report bugs].
 |=================================
 
+[[index-config-info]]
+=== IndexConfigInfo
+The `IndexConfigInfo` entity contains information about Gerrit
+configuration from the link:config-gerrit.html#index[index]
+section.
+
+[options="header",cols="1,^1,5"]
+|=============================
+|Field Name           ||Description
+|`change`                  ||
+Information about the configuration from the
+link:config-gerrit.html#index.change[index.change] section as
+link:#index.change[ChangeIndexConfigInfo] entity.
+|=============================
+
 [[hit-ration-info]]
 === HitRatioInfo
 The `HitRatioInfo` entity contains information about the hit ratio of a
@@ -1947,6 +1977,10 @@ information about Gerrit
 Information about the configuration from the
 link:config-gerrit.html#gerrit[gerrit] section as link:#gerrit-info[
 GerritInfo] entity.
+|`index`                  ||
+Information about the configuration from the
+link:config-gerrit.html#index[index] section as link:#index[
+IndexConfigInfo] entity.
 |`note_db_enabled`         |not set if `false`|
 Whether the NoteDb storage backend is fully enabled.
 |`plugin`                  ||

java/com/google/gerrit/extensions/common/ChangeIndexConfigInfo.java

@@ -0,0 +1,19 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// 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
+//
+// http://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 com.google.gerrit.extensions.common;
+
+public class ChangeIndexConfigInfo {
+  public Boolean indexMergeable;
+}

java/com/google/gerrit/extensions/common/IndexConfigInfo.java

@@ -0,0 +1,19 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// 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
+//
+// http://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 com.google.gerrit.extensions.common;
+
+public class IndexConfigInfo {
+  public ChangeIndexConfigInfo change;
+}

java/com/google/gerrit/extensions/common/ServerInfo.java

@@ -20,6 +20,7 @@ public class ServerInfo {
   public ChangeConfigInfo change;
   public DownloadInfo download;
   public GerritInfo gerrit;
+  public IndexConfigInfo index;
   public Boolean noteDbEnabled;
   public PluginConfigInfo plugin;
   public SshdInfo sshd;

java/com/google/gerrit/server/restapi/config/GetServerInfo.java

@@ -23,9 +23,11 @@ import com.google.gerrit.common.data.ContributorAgreement;
 import com.google.gerrit.extensions.common.AccountsInfo;
 import com.google.gerrit.extensions.common.AuthInfo;
 import com.google.gerrit.extensions.common.ChangeConfigInfo;
+import com.google.gerrit.extensions.common.ChangeIndexConfigInfo;
 import com.google.gerrit.extensions.common.DownloadInfo;
 import com.google.gerrit.extensions.common.DownloadSchemeInfo;
 import com.google.gerrit.extensions.common.GerritInfo;
+import com.google.gerrit.extensions.common.IndexConfigInfo;
 import com.google.gerrit.extensions.common.PluginConfigInfo;
 import com.google.gerrit.extensions.common.ReceiveInfo;
 import com.google.gerrit.extensions.common.ServerInfo;
@@ -141,6 +143,7 @@ public class GetServerInfo implements RestReadView<ConfigResource> {
     info.change = getChangeInfo();
     info.download = getDownloadInfo();
     info.gerrit = getGerritInfo();
+    info.index = getIndexInfo();
     info.noteDbEnabled = true;
     info.plugin = getPluginInfo();
     info.defaultTheme = getDefaultTheme();
@@ -296,6 +299,14 @@ public class GetServerInfo implements RestReadView<ConfigResource> {
     return info;
   }
 
+  private IndexConfigInfo getIndexInfo() {
+    ChangeIndexConfigInfo change = new ChangeIndexConfigInfo();
+    change.indexMergeable = toBoolean(config.getBoolean("index", "change", "indexMergeable", true));
+    IndexConfigInfo index = new IndexConfigInfo();
+    index.change = change;
+    return index;
+  }
+
   private String getDocUrl() {
     String docUrl = config.getString("gerrit", null, "docUrl");
     if (Strings.isNullOrEmpty(docUrl)) {

javatests/com/google/gerrit/acceptance/rest/config/ServerInfoIT.java

@@ -180,6 +180,9 @@ public class ServerInfoIT extends AbstractDaemonTest {
     assertThat(i.gerrit.allUsers).isEqualTo(AllUsersNameProvider.DEFAULT);
     assertThat(i.gerrit.reportBugUrl).isNull();
 
+    // index
+    assertThat(i.index.change.indexMergeable).isNull(); // false in all tests
+
     // plugin
     assertThat(i.plugin.jsResourcePaths).isEmpty();
 
@@ -206,4 +209,11 @@ public class ServerInfoIT extends AbstractDaemonTest {
     ServerInfo i = gApi.config().server().getInfo();
     assertThat(i.change.excludeMergeableInChangeInfo).isTrue();
   }
+
+  @Test
+  @GerritConfig(name = "index.change.indexMergeable", value = "true")
+  public void indexMergeableIsTrueWhenTrueInConfig() throws Exception {
+    ServerInfo i = gApi.config().server().getInfo();
+    assertThat(i.index.change.indexMergeable).isTrue();
+  }
 }