Rename Action to ActionType (#43778)

Action is a class that encapsulates meta information about an action
that allows it to be called remotely, specifically the action name and
response type. With recent refactoring, the action class can now be
constructed as a static constant, instead of needing to create a
subclass. This makes the old pattern of creating a singleton INSTANCE
both misnamed and lacking a common placement.

This commit renames Action to ActionType, thus allowing the old INSTANCE
naming pattern to be TYPE on the transport action itself. ActionType
also conveys that this class is also not the action itself, although
this change does not rename any concrete classes as those will be
removed organically as they are converted to TYPE constants.

relates #34389

client/client-benchmark-noop-api-plugin/src/main/java/org/elasticsearch/plugin/noop/action/bulk/NoopBulkAction.java

@@ -18,10 +18,10 @@
  */
 package org.elasticsearch.plugin.noop.action.bulk;
 
-import org.elasticsearch.action.StreamableResponseAction;
+import org.elasticsearch.action.StreamableResponseActionType;
 import org.elasticsearch.action.bulk.BulkResponse;
 
-public class NoopBulkAction extends StreamableResponseAction<BulkResponse> {
+public class NoopBulkAction extends StreamableResponseActionType<BulkResponse> {
     public static final String NAME = "mock:data/write/bulk";
 
     public static final NoopBulkAction INSTANCE = new NoopBulkAction();

client/client-benchmark-noop-api-plugin/src/main/java/org/elasticsearch/plugin/noop/action/search/NoopSearchAction.java

@@ -18,11 +18,11 @@
  */
 package org.elasticsearch.plugin.noop.action.search;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.common.io.stream.Writeable;
 
-public class NoopSearchAction extends Action<SearchResponse> {
+public class NoopSearchAction extends ActionType<SearchResponse> {
     public static final NoopSearchAction INSTANCE = new NoopSearchAction();
     public static final String NAME = "mock:data/read/search";
 

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/GrokProcessorGetAction.java

@@ -22,7 +22,7 @@
 import org.elasticsearch.action.ActionRequest;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.ActionResponse;
-import org.elasticsearch.action.StreamableResponseAction;
+import org.elasticsearch.action.StreamableResponseActionType;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.HandledTransportAction;
 import org.elasticsearch.client.node.NodeClient;
@@ -45,7 +45,7 @@
 import static org.elasticsearch.ingest.common.IngestCommonPlugin.GROK_PATTERNS;
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 
-public class GrokProcessorGetAction extends StreamableResponseAction<GrokProcessorGetAction.Response> {
+public class GrokProcessorGetAction extends StreamableResponseActionType<GrokProcessorGetAction.Response> {
 
     static final GrokProcessorGetAction INSTANCE = new GrokProcessorGetAction();
     static final String NAME = "cluster:admin/ingest/processor/grok/get";

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

@@ -19,10 +19,10 @@
 
 package org.elasticsearch.script.mustache;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.common.io.stream.Writeable;
 
-public class MultiSearchTemplateAction extends Action<MultiSearchTemplateResponse> {
+public class MultiSearchTemplateAction extends ActionType<MultiSearchTemplateResponse> {
 
     public static final MultiSearchTemplateAction INSTANCE = new MultiSearchTemplateAction();
     public static final String NAME = "indices:data/read/msearch/template";

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

@@ -19,10 +19,10 @@
 
 package org.elasticsearch.script.mustache;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.common.io.stream.Writeable;
 
-public class SearchTemplateAction extends Action<SearchTemplateResponse> {
+public class SearchTemplateAction extends ActionType<SearchTemplateResponse> {
 
     public static final SearchTemplateAction INSTANCE = new SearchTemplateAction();
     public static final String NAME = "indices:data/read/search/template";

modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessContextAction.java

@@ -19,7 +19,7 @@
 
 package org.elasticsearch.painless.action;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.ActionRequest;
 import org.elasticsearch.action.ActionRequestValidationException;
@@ -64,7 +64,7 @@
  *     retrieves all available information about the API for this specific context</li>
  * </ul>
  */
-public class PainlessContextAction extends Action<PainlessContextAction.Response> {
+public class PainlessContextAction extends ActionType<PainlessContextAction.Response> {
 
     public static final PainlessContextAction INSTANCE = new PainlessContextAction();
     private static final String NAME = "cluster:admin/scripts/painless/context";

modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessExecuteAction.java

@@ -30,7 +30,7 @@
 import org.apache.lucene.search.Scorer;
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.store.RAMDirectory;
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.ActionResponse;
 import org.elasticsearch.action.support.ActionFilters;
@@ -89,7 +89,7 @@
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
-public class PainlessExecuteAction extends Action<PainlessExecuteAction.Response> {
+public class PainlessExecuteAction extends ActionType<PainlessExecuteAction.Response> {
 
     public static final PainlessExecuteAction INSTANCE = new PainlessExecuteAction();
     private static final String NAME = "cluster:admin/scripts/painless/execute";

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankEvalAction.java

@@ -19,12 +19,12 @@
 
 package org.elasticsearch.index.rankeval;
 
-import org.elasticsearch.action.StreamableResponseAction;
+import org.elasticsearch.action.StreamableResponseActionType;
 
 /**
- * Action for explaining evaluating search ranking results.
+ * ActionType for explaining evaluating search ranking results.
  */
-public class RankEvalAction extends StreamableResponseAction<RankEvalResponse> {
+public class RankEvalAction extends StreamableResponseActionType<RankEvalResponse> {
 
     public static final RankEvalAction INSTANCE = new RankEvalAction();
     public static final String NAME = "indices:data/read/rank_eval";

modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankEvalRequestBuilder.java

@@ -19,13 +19,13 @@
 
 package org.elasticsearch.index.rankeval;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.ActionRequestBuilder;
 import org.elasticsearch.client.ElasticsearchClient;
 
 public class RankEvalRequestBuilder extends ActionRequestBuilder<RankEvalRequest, RankEvalResponse> {
 
-    public RankEvalRequestBuilder(ElasticsearchClient client, Action<RankEvalResponse> action,
+    public RankEvalRequestBuilder(ElasticsearchClient client, ActionType<RankEvalResponse> action,
             RankEvalRequest request) {
         super(client, action, request);
     }

modules/reindex/src/main/java/org/elasticsearch/index/reindex/AbstractBaseReindexRestHandler.java

@@ -19,7 +19,7 @@
 
 package org.elasticsearch.index.reindex;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.support.ActiveShardCount;
 import org.elasticsearch.client.node.NodeClient;
@@ -38,7 +38,7 @@
 
 public abstract class AbstractBaseReindexRestHandler<
                 Request extends AbstractBulkByScrollRequest<Request>,
-                A extends Action<BulkByScrollResponse>
+                A extends ActionType<BulkByScrollResponse>
             > extends BaseRestHandler {
 
     private final A action;

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

@@ -19,7 +19,7 @@
 
 package org.elasticsearch.index.reindex;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.settings.Settings;
@@ -38,7 +38,7 @@
  */
 public abstract class AbstractBulkByQueryRestHandler<
         Request extends AbstractBulkByScrollRequest<Request>,
-        A extends Action<BulkByScrollResponse>> extends AbstractBaseReindexRestHandler<Request, A> {
+        A extends ActionType<BulkByScrollResponse>> extends AbstractBaseReindexRestHandler<Request, A> {
 
     protected AbstractBulkByQueryRestHandler(Settings settings, A action) {
         super(settings, action);

modules/reindex/src/main/java/org/elasticsearch/index/reindex/BulkByScrollParallelizationHelper.java

@@ -19,7 +19,7 @@
 
 package org.elasticsearch.index.reindex;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.admin.cluster.shards.ClusterSearchShardsRequest;
 import org.elasticsearch.action.admin.cluster.shards.ClusterSearchShardsResponse;
@@ -61,7 +61,7 @@ private BulkByScrollParallelizationHelper() {}
     static <Request extends AbstractBulkByScrollRequest<Request>> void startSlicedAction(
             Request request,
             BulkByScrollTask task,
-            Action<BulkByScrollResponse> action,
+            ActionType<BulkByScrollResponse> action,
             ActionListener<BulkByScrollResponse> listener,
             Client client,
             DiscoveryNode node,
@@ -85,7 +85,7 @@ static <Request extends AbstractBulkByScrollRequest<Request>> void startSlicedAc
     private static <Request extends AbstractBulkByScrollRequest<Request>> void sliceConditionally(
             Request request,
             BulkByScrollTask task,
-            Action<BulkByScrollResponse> action,
+            ActionType<BulkByScrollResponse> action,
             ActionListener<BulkByScrollResponse> listener,
             Client client,
             DiscoveryNode node,
@@ -118,7 +118,7 @@ private static int countSlicesBasedOnShards(ClusterSearchShardsResponse response
 
     private static <Request extends AbstractBulkByScrollRequest<Request>> void sendSubRequests(
             Client client,
-            Action<BulkByScrollResponse> action,
+            ActionType<BulkByScrollResponse> action,
             String localNodeId,
             BulkByScrollTask task,
             Request request,

modules/reindex/src/main/java/org/elasticsearch/index/reindex/RethrottleAction.java

@@ -19,11 +19,11 @@
 
 package org.elasticsearch.index.reindex;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.admin.cluster.node.tasks.list.ListTasksResponse;
 import org.elasticsearch.common.io.stream.Writeable;
 
-public class RethrottleAction extends Action<ListTasksResponse> {
+public class RethrottleAction extends ActionType<ListTasksResponse> {
     public static final RethrottleAction INSTANCE = new RethrottleAction();
     public static final String NAME = "cluster:admin/reindex/rethrottle";
 

modules/reindex/src/main/java/org/elasticsearch/index/reindex/RethrottleRequestBuilder.java

@@ -19,7 +19,7 @@
 
 package org.elasticsearch.index.reindex;
 
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.admin.cluster.node.tasks.list.ListTasksResponse;
 import org.elasticsearch.action.support.tasks.TasksRequestBuilder;
 import org.elasticsearch.client.ElasticsearchClient;
@@ -29,7 +29,7 @@
  */
 public class RethrottleRequestBuilder extends TasksRequestBuilder<RethrottleRequest, ListTasksResponse, RethrottleRequestBuilder> {
     public RethrottleRequestBuilder(ElasticsearchClient client,
-            Action<ListTasksResponse> action) {
+            ActionType<ListTasksResponse> action) {
         super(client, action, new RethrottleRequest());
     }
 

modules/reindex/src/test/java/org/elasticsearch/index/reindex/AsyncBulkByScrollActionTests.java

@@ -23,7 +23,7 @@
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.Version;
-import org.elasticsearch.action.Action;
+import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.ActionRequest;
 import org.elasticsearch.action.ActionResponse;
@@ -761,7 +761,7 @@ private class MyMockClient extends FilterClient {
         @Override
         @SuppressWarnings("unchecked")
         protected <Request extends ActionRequest, Response extends ActionResponse>
-        void doExecute(Action<Response> action, Request request, ActionListener<Response> listener) {
+        void doExecute(ActionType<Response> action, Request request, ActionListener<Response> listener) {
             if (false == expectedHeaders.equals(threadPool().getThreadContext().getHeaders())) {
                 listener.onFailure(
                         new RuntimeException("Expected " + expectedHeaders + " but got " + threadPool().getThreadContext().getHeaders()));

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

@@ -412,7 +412,7 @@ public void register(ActionHandler<?, ?> handler) {
             }
 
             public <Request extends ActionRequest, Response extends ActionResponse> void register(
-                Action<Response> action, Class<? extends TransportAction<Request, Response>> transportAction) {
+                ActionType<Response> action, Class<? extends TransportAction<Request, Response>> transportAction) {
                 register(new ActionHandler<>(action, transportAction));
             }
         }
@@ -460,7 +460,7 @@ public <Request extends ActionRequest, Response extends ActionResponse> void reg
         actions.register(CloseIndexAction.INSTANCE, TransportCloseIndexAction.class);
         actions.register(GetMappingsAction.INSTANCE, TransportGetMappingsAction.class);
         actions.register(GetFieldMappingsAction.INSTANCE, TransportGetFieldMappingsAction.class);
-        actions.register(TransportGetFieldMappingsIndexAction.ACTION_INSTANCE, TransportGetFieldMappingsIndexAction.class);
+        actions.register(TransportGetFieldMappingsIndexAction.TYPE, TransportGetFieldMappingsIndexAction.class);
         actions.register(PutMappingAction.INSTANCE, TransportPutMappingAction.class);
         actions.register(IndicesAliasesAction.INSTANCE, TransportIndicesAliasesAction.class);
         actions.register(UpdateSettingsAction.INSTANCE, TransportUpdateSettingsAction.class);
@@ -484,13 +484,13 @@ public <Request extends ActionRequest, Response extends ActionResponse> void reg
         actions.register(GetAction.INSTANCE, TransportGetAction.class);
         actions.register(TermVectorsAction.INSTANCE, TransportTermVectorsAction.class);
         actions.register(MultiTermVectorsAction.INSTANCE, TransportMultiTermVectorsAction.class);
-        actions.register(TransportShardMultiTermsVectorAction.ACTION_INSTANCE, TransportShardMultiTermsVectorAction.class);
+        actions.register(TransportShardMultiTermsVectorAction.TYPE, TransportShardMultiTermsVectorAction.class);
         actions.register(DeleteAction.INSTANCE, TransportDeleteAction.class);
         actions.register(UpdateAction.INSTANCE, TransportUpdateAction.class);
         actions.register(MultiGetAction.INSTANCE, TransportMultiGetAction.class);
-        actions.register(TransportShardMultiGetAction.ACTION_INSTANCE, TransportShardMultiGetAction.class);
+        actions.register(TransportShardMultiGetAction.TYPE, TransportShardMultiGetAction.class);
         actions.register(BulkAction.INSTANCE, TransportBulkAction.class);
-        actions.register(TransportShardBulkAction.ACTION_INSTANCE, TransportShardBulkAction.class);
+        actions.register(TransportShardBulkAction.TYPE, TransportShardBulkAction.class);
         actions.register(SearchAction.INSTANCE, TransportSearchAction.class);
         actions.register(SearchScrollAction.INSTANCE, TransportSearchScrollAction.class);
         actions.register(MultiSearchAction.INSTANCE, TransportMultiSearchAction.class);
@@ -505,7 +505,7 @@ public <Request extends ActionRequest, Response extends ActionResponse> void reg
         actions.register(DeleteStoredScriptAction.INSTANCE, TransportDeleteStoredScriptAction.class);
 
         actions.register(FieldCapabilitiesAction.INSTANCE, TransportFieldCapabilitiesAction.class);
-        actions.register(TransportFieldCapabilitiesIndexAction.ACTION_INSTANCE, TransportFieldCapabilitiesIndexAction.class);
+        actions.register(TransportFieldCapabilitiesIndexAction.TYPE, TransportFieldCapabilitiesIndexAction.class);
 
         actions.register(PutPipelineAction.INSTANCE, PutPipelineTransportAction.class);
         actions.register(GetPipelineAction.INSTANCE, GetPipelineTransportAction.class);
@@ -684,10 +684,10 @@ protected void configure() {
         bind(AutoCreateIndex.class).toInstance(autoCreateIndex);
         bind(TransportLivenessAction.class).asEagerSingleton();
 
-        // register Action -> transportAction Map used by NodeClient
+        // register ActionType -> transportAction Map used by NodeClient
         @SuppressWarnings("rawtypes")
-        MapBinder<Action, TransportAction> transportActionsBinder
-                = MapBinder.newMapBinder(binder(), Action.class, TransportAction.class);
+        MapBinder<ActionType, TransportAction> transportActionsBinder
+                = MapBinder.newMapBinder(binder(), ActionType.class, TransportAction.class);
         for (ActionHandler<?, ?> action : actions.values()) {
             // bind the action as eager singleton, so the map binder one will reuse it
             bind(action.getTransportAction()).asEagerSingleton();

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

@@ -26,11 +26,11 @@
 
 public abstract class ActionRequestBuilder<Request extends ActionRequest, Response extends ActionResponse> {
 
-    protected final Action<Response> action;
+    protected final ActionType<Response> action;
     protected final Request request;
     protected final ElasticsearchClient client;
 
-    protected ActionRequestBuilder(ElasticsearchClient client, Action<Response> action, Request request) {
+    protected ActionRequestBuilder(ElasticsearchClient client, ActionType<Response> action, Request request) {
         Objects.requireNonNull(action, "action must not be null");
         this.action = action;
         this.request = request;

server/src/main/java/org/elasticsearch/action/Action.java → server/src/main/java/org/elasticsearch/action/ActionType.java

@@ -26,7 +26,7 @@
 /**
  * A generic action. Should strive to make it a singleton.
  */
-public class Action<Response extends ActionResponse> {
+public class ActionType<Response extends ActionResponse> {
 
     private final String name;
     private final Writeable.Reader<Response> responseReader;
@@ -36,15 +36,15 @@ public class Action<Response extends ActionResponse> {
      * @deprecated Pass a {@link Writeable.Reader} with {@link }
      */
     @Deprecated
-    protected Action(String name) {
+    protected ActionType(String name) {
         this(name, null);
     }
 
     /**
      * @param name The name of the action, must be unique across actions.
      * @param responseReader A reader for the response type
      */
-    public Action(String name, Writeable.Reader<Response> responseReader) {
+    public ActionType(String name, Writeable.Reader<Response> responseReader) {
         this.name = name;
         this.responseReader = responseReader;
     }
@@ -72,7 +72,7 @@ public TransportRequestOptions transportOptions(Settings settings) {
 
     @Override
     public boolean equals(Object o) {
-        return o instanceof Action && name.equals(((Action<?>) o).name());
+        return o instanceof ActionType && name.equals(((ActionType<?>) o).name());
     }
 
     @Override

server/src/main/java/org/elasticsearch/action/StreamableResponseAction.java → server/src/main/java/org/elasticsearch/action/StreamableResponseActionType.java

@@ -23,12 +23,12 @@
 
 /**
  * An action for with the response type implements {@link org.elasticsearch.common.io.stream.Streamable}.
- * @deprecated Use {@link Action} directly and provide a {@link Writeable.Reader}
+ * @deprecated Use {@link ActionType} directly and provide a {@link Writeable.Reader}
  */
 @Deprecated
-public abstract class StreamableResponseAction<Response extends ActionResponse> extends Action<Response> {
+public abstract class StreamableResponseActionType<Response extends ActionResponse> extends ActionType<Response> {
 
-    protected StreamableResponseAction(String name) {
+    protected StreamableResponseActionType(String name) {
         super(name);
     }
 

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

@@ -30,10 +30,10 @@
 public class TransportActionNodeProxy<Request extends ActionRequest, Response extends ActionResponse> {
 
     private final TransportService transportService;
-    private final Action<Response> action;
+    private final ActionType<Response> action;
     private final TransportRequestOptions transportOptions;
 
-    public TransportActionNodeProxy(Settings settings, Action<Response> action, TransportService transportService) {
+    public TransportActionNodeProxy(Settings settings, ActionType<Response> action, TransportService transportService) {
         this.action = action;
         this.transportService = transportService;
         this.transportOptions = action.transportOptions(settings);