Codegen decorator class

codegen/src/main/java/software/amazon/awssdk/codegen/docs/AsyncOperationDocProvider.java

@@ -15,6 +15,10 @@
 
 package software.amazon.awssdk.codegen.docs;
 
+
+import static software.amazon.awssdk.codegen.internal.Constant.ASYNC_STREAMING_INPUT_PARAM;
+import static software.amazon.awssdk.codegen.internal.Constant.ASYNC_STREAMING_OUTPUT_PARAM;
+
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
 
@@ -66,10 +70,10 @@ protected void applyReturns(DocumentationBuilder docBuilder) {
     protected void applyParams(DocumentationBuilder docBuilder) {
         emitRequestParm(docBuilder);
         if (opModel.hasStreamingInput()) {
-            docBuilder.param("requestBody", REQUEST_BODY_DOCS + getStreamingInputDocs());
+            docBuilder.param(ASYNC_STREAMING_INPUT_PARAM, REQUEST_BODY_DOCS + getStreamingInputDocs());
         }
         if (opModel.hasStreamingOutput()) {
-            docBuilder.param("asyncResponseTransformer", STREAM_RESPONSE_TRANSFORMER_DOCS + getStreamingOutputDocs());
+            docBuilder.param(ASYNC_STREAMING_OUTPUT_PARAM, STREAM_RESPONSE_TRANSFORMER_DOCS + getStreamingOutputDocs());
         }
     }
 

codegen/src/main/java/software/amazon/awssdk/codegen/docs/PaginationDocs.java

@@ -24,7 +24,7 @@
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
 import software.amazon.awssdk.codegen.model.service.PaginatorDefinition;
-import software.amazon.awssdk.codegen.poet.PoetExtensions;
+import software.amazon.awssdk.codegen.poet.PoetExtension;
 import software.amazon.awssdk.codegen.utils.PaginatorUtils;
 import software.amazon.awssdk.utils.async.SequentialSubscriber;
 
@@ -33,13 +33,13 @@ public class PaginationDocs {
     private static final String SUBSCRIBE_METHOD_NAME = "subscribe";
 
     private final OperationModel operationModel;
-    private final PoetExtensions poetExtensions;
+    private final PoetExtension poetExtensions;
     private final PaginatorDefinition paginatorDefinition;
 
     public PaginationDocs(IntermediateModel intermediateModel, OperationModel operationModel,
                           PaginatorDefinition paginatorDefinition) {
         this.operationModel = operationModel;
-        this.poetExtensions = new PoetExtensions(intermediateModel);
+        this.poetExtensions = new PoetExtension(intermediateModel);
         this.paginatorDefinition = paginatorDefinition;
     }
 

codegen/src/main/java/software/amazon/awssdk/codegen/docs/SyncOperationDocProvider.java

@@ -17,6 +17,8 @@
 
 import static software.amazon.awssdk.codegen.internal.Constant.SYNC_CLIENT_DESTINATION_PATH_PARAM_NAME;
 import static software.amazon.awssdk.codegen.internal.Constant.SYNC_CLIENT_SOURCE_PATH_PARAM_NAME;
+import static software.amazon.awssdk.codegen.internal.Constant.SYNC_STREAMING_INPUT_PARAM;
+import static software.amazon.awssdk.codegen.internal.Constant.SYNC_STREAMING_OUTPUT_PARAM;
 
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
@@ -76,11 +78,11 @@ protected void applyReturns(DocumentationBuilder docBuilder) {
     protected void applyParams(DocumentationBuilder docBuilder) {
         emitRequestParm(docBuilder);
         if (opModel.hasStreamingInput()) {
-            docBuilder.param("requestBody", REQUEST_BODY_DOCS + getStreamingInputDocs());
+            docBuilder.param(SYNC_STREAMING_INPUT_PARAM, REQUEST_BODY_DOCS + getStreamingInputDocs());
 
         }
         if (opModel.hasStreamingOutput()) {
-            docBuilder.param("responseTransformer", STREAM_RESPONSE_HANDLER_DOCS + getStreamingOutputDocs(),
+            docBuilder.param(SYNC_STREAMING_OUTPUT_PARAM, STREAM_RESPONSE_HANDLER_DOCS + getStreamingOutputDocs(),
                              opModel.getOutputShape().getShapeName(), getStreamingOutputDocs());
         }
     }

codegen/src/main/java/software/amazon/awssdk/codegen/emitters/GeneratorTaskParams.java

@@ -20,7 +20,7 @@
 import org.slf4j.LoggerFactory;
 import software.amazon.awssdk.codegen.emitters.tasks.SharedModelsTaskParamsValidator;
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
-import software.amazon.awssdk.codegen.poet.PoetExtensions;
+import software.amazon.awssdk.codegen.poet.PoetExtension;
 
 /**
  * Parameters for generator tasks.
@@ -30,14 +30,14 @@ public class GeneratorTaskParams {
 
     private final IntermediateModel model;
     private final GeneratorPathProvider pathProvider;
-    private final PoetExtensions poetExtensions;
+    private final PoetExtension poetExtensions;
     private final Logger log = LoggerFactory.getLogger(GeneratorTaskParams.class);
 
     private GeneratorTaskParams(IntermediateModel model,
                                 GeneratorPathProvider pathProvider) {
         this.model = model;
         this.pathProvider = pathProvider;
-        this.poetExtensions = new PoetExtensions(model);
+        this.poetExtensions = new PoetExtension(model);
     }
 
     public static GeneratorTaskParams create(IntermediateModel model, String sourceDirectory, String testDirectory) {
@@ -64,7 +64,7 @@ public GeneratorPathProvider getPathProvider() {
     /**
      * @return Extensions and convenience methods for Java Poet.
      */
-    public PoetExtensions getPoetExtensions() {
+    public PoetExtension getPoetExtensions() {
         return poetExtensions;
     }
 

codegen/src/main/java/software/amazon/awssdk/codegen/emitters/tasks/AsyncClientGeneratorTasks.java

@@ -24,6 +24,7 @@
 import software.amazon.awssdk.codegen.poet.builder.AsyncClientBuilderInterface;
 import software.amazon.awssdk.codegen.poet.client.AsyncClientClass;
 import software.amazon.awssdk.codegen.poet.client.AsyncClientInterface;
+import software.amazon.awssdk.codegen.poet.client.DelegatingAsyncClientClass;
 import software.amazon.awssdk.codegen.poet.endpointdiscovery.EndpointDiscoveryAsyncCacheLoaderGenerator;
 
 public class AsyncClientGeneratorTasks extends BaseGeneratorTasks {
@@ -46,13 +47,21 @@ protected List<GeneratorTask> createTasks() throws Exception {
             generatorTasks.add(createEndpointDiscoveryCacheLoaderTask());
         }
 
+        if (model.getCustomizationConfig().isDelegateAsyncClientClass()) {
+            generatorTasks.add(createDecoratorClientClassTask());
+        }
+
         return generatorTasks;
     }
 
     private GeneratorTask createClientClassTask() throws IOException {
         return createPoetGeneratorTask(new AsyncClientClass(generatorTaskParams));
     }
 
+    private GeneratorTask createDecoratorClientClassTask() throws IOException {
+        return createPoetGeneratorTask(new DelegatingAsyncClientClass(model));
+    }
+
     private GeneratorTask createClientBuilderTask() throws IOException {
         return createPoetGeneratorTask(new AsyncClientBuilderClass(model));
     }

codegen/src/main/java/software/amazon/awssdk/codegen/internal/Constant.java

@@ -92,6 +92,13 @@ public final class Constant {
 
     public static final String APPROVED_SIMPLE_METHOD_VERBS = "(get|list|describe|lookup|batchGet).*";
 
+    public static final String ASYNC_STREAMING_INPUT_PARAM = "requestBody";
+    public static final String ASYNC_STREAMING_OUTPUT_PARAM = "asyncResponseTransformer";
+    public static final String SYNC_STREAMING_INPUT_PARAM = "requestBody";
+    public static final String SYNC_STREAMING_OUTPUT_PARAM = "responseTransformer";
+    public static final String EVENT_PUBLISHER_PARAM_NAME = "requestStream";
+    public static final String EVENT_RESPONSE_HANDLER_PARAM_NAME = "asyncResponseHandler";
+
     private Constant() {
     }
 }

codegen/src/main/java/software/amazon/awssdk/codegen/model/config/customization/CustomizationConfig.java

@@ -196,7 +196,10 @@ public class CustomizationConfig {
 
     private RetryMode defaultRetryMode;
 
-
+    /**
+     * Whether to generate an abstract decorator class that delegates to the async service client
+     */
+    private boolean delegateAsyncClientClass;
 
     private CustomizationConfig() {
     }
@@ -502,4 +505,12 @@ public ServiceConfig getServiceConfig() {
     public void setServiceConfig(ServiceConfig serviceConfig) {
         this.serviceConfig = serviceConfig;
     }
+
+    public boolean isDelegateAsyncClientClass() {
+        return delegateAsyncClientClass;
+    }
+
+    public void setDelegateAsyncClientClass(boolean delegateAsyncClientClass) {
+        this.delegateAsyncClientClass = delegateAsyncClientClass;
+    }
 }

codegen/src/main/java/software/amazon/awssdk/codegen/model/intermediate/Metadata.java

@@ -678,4 +678,8 @@ public String getFullWaitersPackageName() {
     public String getFullWaitersInternalPackageName() {
         return joinPackageNames(getFullWaitersPackageName(), "internal");
     }
+
+    public String getFullInternalPackageName() {
+        return joinPackageNames(getFullClientPackageName(), "internal");
+    }
 }

codegen/src/main/java/software/amazon/awssdk/codegen/poet/PoetExtensions.java → codegen/src/main/java/software/amazon/awssdk/codegen/poet/PoetExtension.java

@@ -25,11 +25,11 @@
 /**
  * Extension and convenience methods to Poet that use the intermediate model.
  */
-public class PoetExtensions {
+public class PoetExtension {
 
     private final IntermediateModel model;
 
-    public PoetExtensions(IntermediateModel model) {
+    public PoetExtension(IntermediateModel model) {
         this.model = model;
     }
 

codegen/src/main/java/software/amazon/awssdk/codegen/poet/client/AsyncClientClass.java

@@ -20,6 +20,7 @@
 import static javax.lang.model.element.Modifier.FINAL;
 import static javax.lang.model.element.Modifier.PRIVATE;
 import static javax.lang.model.element.Modifier.STATIC;
+import static software.amazon.awssdk.codegen.internal.Constant.EVENT_PUBLISHER_PARAM_NAME;
 import static software.amazon.awssdk.codegen.poet.client.ClientClassUtils.addS3ArnableFieldCode;
 import static software.amazon.awssdk.codegen.poet.client.ClientClassUtils.applyPaginatorUserAgentMethod;
 import static software.amazon.awssdk.codegen.poet.client.ClientClassUtils.applySignerOverrideMethod;
@@ -58,7 +59,7 @@
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
 import software.amazon.awssdk.codegen.model.intermediate.ShapeModel;
 import software.amazon.awssdk.codegen.model.service.AuthType;
-import software.amazon.awssdk.codegen.poet.PoetExtensions;
+import software.amazon.awssdk.codegen.poet.PoetExtension;
 import software.amazon.awssdk.codegen.poet.PoetUtils;
 import software.amazon.awssdk.codegen.poet.StaticImport;
 import software.amazon.awssdk.codegen.poet.client.specs.ProtocolSpec;
@@ -85,7 +86,7 @@
 
 public final class AsyncClientClass extends AsyncClientInterface {
     private final IntermediateModel model;
-    private final PoetExtensions poetExtensions;
+    private final PoetExtension poetExtensions;
     private final ClassName className;
     private final ProtocolSpec protocolSpec;
 
@@ -420,7 +421,8 @@ private TypeName eventStreamType(ShapeModel shapeModel) {
         return poetExtensions.getModelClass(shapeModel.getShapeName());
     }
 
-    private MethodSpec utilitiesMethod() {
+    @Override
+    protected MethodSpec utilitiesMethod() {
         UtilitiesMethod config = model.getCustomizationConfig().getUtilitiesMethod();
         ClassName returnType = PoetUtils.classNameFromFqcn(config.getReturnType());
         String instanceClass = config.getInstanceType();

codegen/src/main/java/software/amazon/awssdk/codegen/poet/client/AsyncClientInterface.java

@@ -16,6 +16,9 @@
 package software.amazon.awssdk.codegen.poet.client;
 
 import static java.util.stream.Collectors.toList;
+import static software.amazon.awssdk.codegen.internal.Constant.ASYNC_STREAMING_INPUT_PARAM;
+import static software.amazon.awssdk.codegen.internal.Constant.EVENT_PUBLISHER_PARAM_NAME;
+import static software.amazon.awssdk.codegen.internal.Constant.EVENT_RESPONSE_HANDLER_PARAM_NAME;
 
 import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.FieldSpec;
@@ -43,7 +46,7 @@
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
 import software.amazon.awssdk.codegen.poet.ClassSpec;
-import software.amazon.awssdk.codegen.poet.PoetExtensions;
+import software.amazon.awssdk.codegen.poet.PoetExtension;
 import software.amazon.awssdk.codegen.poet.PoetUtils;
 import software.amazon.awssdk.codegen.poet.eventstream.EventStreamUtils;
 import software.amazon.awssdk.codegen.poet.model.DeprecationUtils;
@@ -57,21 +60,20 @@
 public class AsyncClientInterface implements ClassSpec {
 
     public static final TypeVariableName STREAMING_TYPE_VARIABLE = TypeVariableName.get("ReturnT");
-    protected static final String EVENT_PUBLISHER_PARAM_NAME = "requestStream";
 
     protected final IntermediateModel model;
     protected final ClassName className;
     protected final String clientPackageName;
     private final String modelPackage;
-    private final PoetExtensions poetExtensions;
+    private final PoetExtension poetExtensions;
 
     public AsyncClientInterface(IntermediateModel model) {
         this.modelPackage = model.getMetadata().getFullModelPackageName();
         this.clientPackageName = model.getMetadata().getFullClientPackageName();
         this.model = model;
         this.className = ClassName.get(model.getMetadata().getFullClientPackageName(),
                                        model.getMetadata().getAsyncInterface());
-        this.poetExtensions = new PoetExtensions(model);
+        this.poetExtensions = new PoetExtension(model);
     }
 
     @Override
@@ -304,7 +306,7 @@ private MethodSpec traditionalMethod(OperationModel opModel) {
                 .addJavadoc(opModel.getDocs(model, ClientType.ASYNC));
 
         if (opModel.hasStreamingInput()) {
-            builder.addParameter(ClassName.get(AsyncRequestBody.class), "requestBody");
+            builder.addParameter(ClassName.get(AsyncRequestBody.class), ASYNC_STREAMING_INPUT_PARAM);
         } else if (opModel.hasEventStreamInput()) {
             String eventStreamShapeName = EventStreamUtils.getEventStreamInRequest(opModel.getInputShape())
                                                           .getShapeName();
@@ -319,7 +321,7 @@ private MethodSpec traditionalMethod(OperationModel opModel) {
                 .get(ClassName.get(AsyncResponseTransformer.class), responsePojoType, STREAMING_TYPE_VARIABLE);
             builder.addParameter(asyncResponseHandlerType, "asyncResponseTransformer");
         } else if (opModel.hasEventStreamOutput()) {
-            builder.addParameter(poetExtensions.eventStreamResponseHandlerType(opModel), "asyncResponseHandler");
+            builder.addParameter(poetExtensions.eventStreamResponseHandlerType(opModel), EVENT_RESPONSE_HANDLER_PARAM_NAME);
         }
         return operationBody(builder, opModel).build();
     }
@@ -448,26 +450,34 @@ private String consumerBuilderJavadoc(OperationModel opModel, SimpleMethodOverlo
         return opModel.getDocs(model, ClientType.ASYNC, overload, new DocConfiguration().isConsumerBuilder(true));
     }
 
-    private MethodSpec utilitiesMethod() {
+    protected MethodSpec utilitiesMethod() {
         UtilitiesMethod config = model.getCustomizationConfig().getUtilitiesMethod();
         ClassName returnType = PoetUtils.classNameFromFqcn(config.getReturnType());
 
-        return MethodSpec.methodBuilder(UtilitiesMethod.METHOD_NAME)
-                         .returns(returnType)
-                         .addModifiers(Modifier.PUBLIC)
-                         .addModifiers(Modifier.DEFAULT)
-                         .addStatement("throw new $T()", UnsupportedOperationException.class)
-                         .addJavadoc("Creates an instance of {@link $T} object with the "
-                                     + "configuration set on this client.", returnType)
-                         .build();
+        MethodSpec.Builder builder = MethodSpec.methodBuilder(UtilitiesMethod.METHOD_NAME)
+                                               .returns(returnType)
+                                               .addModifiers(Modifier.PUBLIC)
+                                               .addJavadoc("Creates an instance of {@link $T} object with the "
+                                                           + "configuration set on this client.", returnType);
+        return utilitiesOperationBody(builder).build();
     }
 
-    private MethodSpec waiterMethod() {
-        return MethodSpec.methodBuilder("waiter")
-                         .addModifiers(Modifier.PUBLIC, Modifier.DEFAULT)
-                         .returns(poetExtensions.getAsyncWaiterInterface())
-                         .addStatement("throw new $T()", UnsupportedOperationException.class)
-                         .addJavadoc(WaiterDocs.waiterMethodInClient(poetExtensions.getAsyncWaiterInterface()))
-                         .build();
+    protected MethodSpec.Builder utilitiesOperationBody(MethodSpec.Builder builder) {
+        return builder.addModifiers(Modifier.DEFAULT).addStatement("throw new $T()", UnsupportedOperationException.class);
+    }
+
+    protected MethodSpec waiterMethod() {
+        MethodSpec.Builder builder = MethodSpec.methodBuilder("waiter")
+                                              .addModifiers(Modifier.PUBLIC)
+                                              .returns(poetExtensions.getAsyncWaiterInterface())
+                                              .addJavadoc(WaiterDocs.waiterMethodInClient(
+                                                  poetExtensions.getAsyncWaiterInterface()));
+
+        return waiterOperationBody(builder).build();
+    }
+
+    protected MethodSpec.Builder waiterOperationBody(MethodSpec.Builder builder) {
+        return builder.addModifiers(Modifier.DEFAULT, Modifier.PUBLIC)
+                      .addStatement("throw new $T()", UnsupportedOperationException.class);
     }
 }

codegen/src/main/java/software/amazon/awssdk/codegen/poet/client/ClientClassUtils.java

@@ -38,7 +38,7 @@
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
 import software.amazon.awssdk.codegen.model.intermediate.ShapeModel;
 import software.amazon.awssdk.codegen.model.service.HostPrefixProcessor;
-import software.amazon.awssdk.codegen.poet.PoetExtensions;
+import software.amazon.awssdk.codegen.poet.PoetExtension;
 import software.amazon.awssdk.codegen.poet.PoetUtils;
 import software.amazon.awssdk.core.ApiName;
 import software.amazon.awssdk.core.signer.Signer;
@@ -85,7 +85,7 @@ static MethodSpec consumerBuilderVariant(MethodSpec spec, String javadoc) {
         return result.build();
     }
 
-    static MethodSpec applyPaginatorUserAgentMethod(PoetExtensions poetExtensions, IntermediateModel model) {
+    static MethodSpec applyPaginatorUserAgentMethod(PoetExtension poetExtensions, IntermediateModel model) {
 
         TypeVariableName typeVariableName =
             TypeVariableName.get("T", poetExtensions.getModelClass(model.getSdkRequestBaseClassName()));
@@ -119,7 +119,7 @@ static MethodSpec applyPaginatorUserAgentMethod(PoetExtensions poetExtensions, I
                          .build();
     }
 
-    static MethodSpec applySignerOverrideMethod(PoetExtensions poetExtensions, IntermediateModel model) {
+    static MethodSpec applySignerOverrideMethod(PoetExtension poetExtensions, IntermediateModel model) {
         String signerOverrideVariable = "signerOverride";
 
         TypeVariableName typeVariableName =

codegen/src/main/java/software/amazon/awssdk/codegen/poet/client/ClientSimpleMethodsIntegrationTests.java

@@ -24,18 +24,18 @@
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
 import software.amazon.awssdk.codegen.poet.ClassSpec;
-import software.amazon.awssdk.codegen.poet.PoetExtensions;
+import software.amazon.awssdk.codegen.poet.PoetExtension;
 import software.amazon.awssdk.codegen.poet.PoetUtils;
 import software.amazon.awssdk.regions.Region;
 
 public class ClientSimpleMethodsIntegrationTests implements ClassSpec {
 
     private final IntermediateModel model;
-    private final PoetExtensions poetExtensions;
+    private final PoetExtension poetExtensions;
 
     public ClientSimpleMethodsIntegrationTests(IntermediateModel model) {
         this.model = model;
-        this.poetExtensions = new PoetExtensions(model);
+        this.poetExtensions = new PoetExtension(model);
     }
 
     @Override