Merge "Remove eTag from RevisionResource, subject to experiment" into stable-3.4

3 files changed, 20 insertions, 4 deletions

diff --git a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
index 9b86a4fe1f..269d1c413a 100644
--- a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
+++ b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
@@ -30,6 +30,7 @@ import static com.google.common.net.HttpHeaders.AUTHORIZATION;
 import static com.google.common.net.HttpHeaders.CONTENT_TYPE;
 import static com.google.common.net.HttpHeaders.ORIGIN;
 import static com.google.common.net.HttpHeaders.VARY;
+import static com.google.gerrit.server.experiments.ExperimentFeaturesConstants.GERRIT_BACKEND_REQUEST_FEATURE_REMOVE_REVISION_ETAG;
 import static java.math.RoundingMode.CEILING;
 import static java.nio.charset.StandardCharsets.ISO_8859_1;
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -110,7 +111,9 @@ import com.google.gerrit.server.RequestListener;
 import com.google.gerrit.server.audit.ExtendedHttpAuditEvent;
 import com.google.gerrit.server.cache.PerThreadCache;
 import com.google.gerrit.server.change.ChangeFinder;
+import com.google.gerrit.server.change.RevisionResource;
 import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.experiments.ExperimentFeatures;
 import com.google.gerrit.server.group.GroupAuditService;
 import com.google.gerrit.server.logging.Metadata;
 import com.google.gerrit.server.logging.PerformanceLogContext;
@@ -252,6 +255,7 @@ public class RestApiServlet extends HttpServlet {
     final PluginSetContext<ExceptionHook> exceptionHooks;
     final Injector injector;
     final DynamicMap<DynamicOptions.DynamicBean> dynamicBeans;
+    final ExperimentFeatures experimentFeatures;
 
     @Inject
     Globals(
@@ -269,7 +273,8 @@ public class RestApiServlet extends HttpServlet {
         RetryHelper retryHelper,
         PluginSetContext<ExceptionHook> exceptionHooks,
         Injector injector,
-        DynamicMap<DynamicOptions.DynamicBean> dynamicBeans) {
+        DynamicMap<DynamicOptions.DynamicBean> dynamicBeans,
+        ExperimentFeatures experimentFeatures) {
       this.currentUser = currentUser;
       this.webSession = webSession;
       this.paramParser = paramParser;
@@ -286,6 +291,7 @@ public class RestApiServlet extends HttpServlet {
       allowOrigin = makeAllowOrigin(config);
       this.injector = injector;
       this.dynamicBeans = dynamicBeans;
+      this.experimentFeatures = experimentFeatures;
     }
 
     private static Pattern makeAllowOrigin(Config cfg) {
@@ -775,6 +781,11 @@ public class RestApiServlet extends HttpServlet {
         TraceContext.newTimer(
             "RestApiServlet#getEtagWithRetry:resource",
             Metadata.builder().restViewName(rsrc.getClass().getSimpleName()).build())) {
+      if (rsrc instanceof RevisionResource
+          && globals.experimentFeatures.isFeatureEnabled(
+              GERRIT_BACKEND_REQUEST_FEATURE_REMOVE_REVISION_ETAG)) {
+        return null;
+      }
       return invokeRestEndpointWithRetry(
           req,
           traceContext,
@@ -1056,7 +1067,7 @@ public class RestApiServlet extends HttpServlet {
 
     if (rsrc instanceof RestResource.HasETag) {
       String have = req.getHeader(HttpHeaders.IF_NONE_MATCH);
-      if (have != null) {
+      if (!Strings.isNullOrEmpty(have)) {
         String eTag = getEtagWithRetry(req, traceContext, (RestResource.HasETag) rsrc);
         return have.equals(eTag);
       }
@@ -1134,7 +1145,9 @@ public class RestApiServlet extends HttpServlet {
       res.setHeader(HttpHeaders.ETAG, eTag);
     } else if (rsrc instanceof RestResource.HasETag) {
       String eTag = getEtagWithRetry(req, traceContext, (RestResource.HasETag) rsrc);
-      res.setHeader(HttpHeaders.ETAG, eTag);
+      if (!Strings.isNullOrEmpty(eTag)) {
+        res.setHeader(HttpHeaders.ETAG, eTag);
+      }
     }
     if (rsrc instanceof RestResource.HasLastModified) {
       res.setDateHeader(
diff --git a/java/com/google/gerrit/server/experiments/ExperimentFeaturesConstants.java b/java/com/google/gerrit/server/experiments/ExperimentFeaturesConstants.java
index af49438c33..0f8557876c 100644
--- a/java/com/google/gerrit/server/experiments/ExperimentFeaturesConstants.java
+++ b/java/com/google/gerrit/server/experiments/ExperimentFeaturesConstants.java
@@ -22,6 +22,9 @@ public class ExperimentFeaturesConstants {
   /** Features that are known experiments and can be referenced in the code. */
   public static String UI_FEATURE_PATCHSET_COMMENTS = "UiFeature__patchset_comments";
 
+  public static String GERRIT_BACKEND_REQUEST_FEATURE_REMOVE_REVISION_ETAG =
+      "GerritBackendRequestFeature__remove_revision_etag";
+
   /** Features, enabled by default in the current release. */
   public static final ImmutableSet<String> DEFAULT_ENABLED_FEATURES =
       ImmutableSet.of(UI_FEATURE_PATCHSET_COMMENTS);
diff --git a/java/com/google/gerrit/server/restapi/change/GetRevisionActions.java b/java/com/google/gerrit/server/restapi/change/GetRevisionActions.java
index 527129cc23..f3c0fb859e 100644
--- a/java/com/google/gerrit/server/restapi/change/GetRevisionActions.java
+++ b/java/com/google/gerrit/server/restapi/change/GetRevisionActions.java
@@ -34,6 +34,6 @@ public class GetRevisionActions implements RestReadView<RevisionResource> {
 
   @Override
   public Response<Map<String, ActionInfo>> apply(RevisionResource rsrc) {
-    return Response.withMustRevalidate(delegate.format(rsrc));
+    return Response.ok(delegate.format(rsrc));
   }
 }