Demo of eventstream with shared events approach 1 - move interface down to specific event impl

codegen/src/main/java/software/amazon/awssdk/codegen/customization/processors/UseLegacyEventGenerationSchemeProcessor.java

@@ -15,14 +15,12 @@
 
 package software.amazon.awssdk.codegen.customization.processors;
 
-import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import software.amazon.awssdk.codegen.customization.CodegenCustomizationProcessor;
+import software.amazon.awssdk.codegen.model.config.customization.CustomizationConfig;
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
-import software.amazon.awssdk.codegen.model.intermediate.MemberModel;
 import software.amazon.awssdk.codegen.model.intermediate.ShapeModel;
 import software.amazon.awssdk.codegen.model.service.ServiceModel;
 
@@ -42,40 +40,18 @@ public void preprocess(ServiceModel serviceModel) {
 
     @Override
     public void postprocess(IntermediateModel intermediateModel) {
-        Map<String, List<String>> useLegacyEventGenerationScheme = intermediateModel.getCustomizationConfig()
-                .getUseLegacyEventGenerationScheme();
+        Map<String, CustomizationConfig.LegacyEventGenerationMode> useLegacyEventGenerationScheme =
+            intermediateModel.getCustomizationConfig().getUseLegacyEventGenerationScheme();
 
         useLegacyEventGenerationScheme.forEach((eventStream, members) -> {
             ShapeModel shapeModel = getShapeByC2jName(intermediateModel, eventStream);
 
             if (shapeModel == null || !shapeModel.isEventStream()) {
                 log.warn(String.format("Encountered %s for unrecognized eventstream %s",
                         CUSTOMIZATION_NAME, eventStream));
-                return;
             }
 
-            Map<String, Integer> shapeToEventCount = new HashMap<>();
-
-            members.forEach(m -> {
-                MemberModel event = shapeModel.getMemberByC2jName(m);
-
-                if (event != null) {
-                    String shapeName = event.getC2jShape();
-                    int count = shapeToEventCount.getOrDefault(shapeName, 0);
-                    shapeToEventCount.put(shapeName, ++count);
-                } else {
-                    String msg = String.format("Encountered %s customization for unrecognized eventstream member %s#%s",
-                            CUSTOMIZATION_NAME, eventStream, m);
-                    log.warn(msg);
-                }
-            });
-
-            shapeToEventCount.forEach((shape, count) -> {
-                if (count > 1) {
-                    throw new IllegalArgumentException(CUSTOMIZATION_NAME + " customization declared for "
-                            + eventStream + ", but more than it targets more than one member with the shape " + shape);
-                }
-            });
+            // TODO: Do we need any additional validation here?
         });
     }
 

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

@@ -24,6 +24,7 @@
 import software.amazon.awssdk.codegen.emitters.GeneratorTask;
 import software.amazon.awssdk.codegen.emitters.GeneratorTaskParams;
 import software.amazon.awssdk.codegen.emitters.PoetGeneratorTask;
+import software.amazon.awssdk.codegen.model.config.customization.CustomizationConfig;
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.MemberModel;
 import software.amazon.awssdk.codegen.model.intermediate.Metadata;
@@ -100,7 +101,8 @@ private List<GeneratorTask> eventModelGenerationTasks() {
 
                     return eventStream.getMembers().stream()
                             .filter(e -> e.getShape().isEvent())
-                            .filter(e -> !eventStreamSpecHelper.useLegacyGenerationScheme(e))
+                            .filter(e -> eventStreamSpecHelper.legacyEventGenerationMode()
+                                         != CustomizationConfig.LegacyEventGenerationMode.NO_ES_EVENT_IMPL)
                             .map(e -> createEventGenerationTask(e, eventStream));
                 })
                 .collect(Collectors.toList());

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

@@ -15,6 +15,7 @@
 
 package software.amazon.awssdk.codegen.model.config.customization;
 
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -35,6 +36,12 @@
  */
 public class CustomizationConfig {
 
+    public enum LegacyEventGenerationMode {
+        DISABLED,
+        NO_ES_EVENT_IMPL, // old legacy
+        TOP_LEVEL_ES_INTERFACE // new legacy
+    }
+
     /**
      * List of 'convenience' overloads to generate for model classes. Convenience overloads expose a
      * different type that is adapted to the real type
@@ -208,7 +215,8 @@ public class CustomizationConfig {
      * generation scheme for the visitor methods was changed. There should be no good reason to use this customization
      * for any other purpose.
      */
-    private Map<String, List<String>> useLegacyEventGenerationScheme = new HashMap<>();
+    @JsonDeserialize(using = UseLegacyEventSchemeDeserializer.class)
+    private Map<String, LegacyEventGenerationMode> useLegacyEventGenerationScheme = new HashMap<>();
 
     /**
      * How the code generator should behave when it encounters shapes with underscores in the name.
@@ -646,11 +654,11 @@ public void setAllowEndpointOverrideForEndpointDiscoveryRequiredOperations(
             allowEndpointOverrideForEndpointDiscoveryRequiredOperations;
     }
 
-    public Map<String, List<String>> getUseLegacyEventGenerationScheme() {
+    public Map<String, LegacyEventGenerationMode> getUseLegacyEventGenerationScheme() {
         return useLegacyEventGenerationScheme;
     }
 
-    public void setUseLegacyEventGenerationScheme(Map<String, List<String>> useLegacyEventGenerationScheme) {
+    public void setUseLegacyEventGenerationScheme(Map<String, LegacyEventGenerationMode> useLegacyEventGenerationScheme) {
         this.useLegacyEventGenerationScheme = useLegacyEventGenerationScheme;
     }
 

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

@@ -0,0 +1,64 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.model.config.customization;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Locale;
+import java.util.Map;
+
+public class UseLegacyEventSchemeDeserializer
+    extends JsonDeserializer<Map<String, CustomizationConfig.LegacyEventGenerationMode>> {
+    @Override
+    public Map<String, CustomizationConfig.LegacyEventGenerationMode> deserialize(
+        JsonParser p, DeserializationContext ctxt) throws IOException {
+
+        Map<String, CustomizationConfig.LegacyEventGenerationMode> result = new HashMap<>();
+
+        JsonNode rootNode = p.getCodec().readTree(p);
+        Iterator<Map.Entry<String, JsonNode>> fields = rootNode.fields();
+
+        while (fields.hasNext()) {
+            Map.Entry<String, JsonNode> field = fields.next();
+            String key = field.getKey();
+            JsonNode valueNode = field.getValue();
+
+            if (valueNode.isArray()) {
+                // Old format: List<String>
+                result.put(key, CustomizationConfig.LegacyEventGenerationMode.NO_ES_EVENT_IMPL);
+            } else if (valueNode.isTextual()) {
+                // New format: Enum name as string
+                try {
+                    CustomizationConfig.LegacyEventGenerationMode value =
+                        CustomizationConfig.LegacyEventGenerationMode.valueOf(
+                            valueNode.asText().toUpperCase(Locale.US));
+                    result.put(key, value);
+                } catch (IllegalArgumentException e) {
+                    throw new IOException("Invalid enum value: " + valueNode.asText(), e);
+                }
+            } else {
+                throw new IOException("Unexpected format for key: " + key);
+            }
+        }
+
+        return result;
+    }
+}

codegen/src/main/java/software/amazon/awssdk/codegen/poet/eventstream/EventStreamVisitorInterfaceSpec.java

@@ -122,7 +122,7 @@ protected MethodSpec.Builder applyVisitSubTypeMethodSpecUpdates(TypeSpec.Builder
             .param("event", "Event being visited")
             .build();
         return methodBuilder.addModifiers(Modifier.DEFAULT)
-                            .addStatement("visitDefault(event)")
+                            .addStatement("visitDefault(($T)event)", eventStreamBaseClass)
                             .addJavadoc(javadocs, eventSubType, eventStreamBaseClass);
     }
 

codegen/src/main/java/software/amazon/awssdk/codegen/poet/model/AwsServiceModel.java

@@ -48,6 +48,7 @@
 import javax.lang.model.element.Modifier;
 import software.amazon.awssdk.annotations.SdkPublicApi;
 import software.amazon.awssdk.codegen.docs.DocumentationBuilder;
+import software.amazon.awssdk.codegen.model.config.customization.CustomizationConfig;
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.MemberModel;
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
@@ -214,6 +215,21 @@ private void addEventSupport(TypeSpec.Builder specBuilder) {
     }
 
     private void addEventSupport(TypeSpec.Builder specBuilder, ShapeModel eventStream) {
+        CustomizationConfig.LegacyEventGenerationMode eventGenerationMode = legacyEventGenerationMode(eventStream);
+        if (eventGenerationMode == CustomizationConfig.LegacyEventGenerationMode.DISABLED) {
+            // for non-legacy cases we do not add ANY eventstream interfaces/methods on the top level/generic POJO
+            // TODO: Document why? or fix marshallers
+            specBuilder.addMethod(MethodSpec.methodBuilder("sdkEventType")
+                                            .addModifiers(PUBLIC)
+                                            .returns(ParameterizedTypeName.get(
+                                                ClassName.get(Enum.class),
+                                                WildcardTypeName.subtypeOf(Object.class)
+                                            ))
+                                            .addStatement("throw new $T()", UnsupportedOperationException.class)
+                                            .build());
+            return;
+        }
+
         ClassName eventStreamClassName = poetExtensions.getModelClassFromShape(eventStream);
         Collection<OperationModel> opModels = EventStreamUtils.findOperationsWithEventStream(intermediateModel,
                                                                                              eventStream);
@@ -225,27 +241,26 @@ private void addEventSupport(TypeSpec.Builder specBuilder, ShapeModel eventStrea
 
         if (!onOutput && !onInput) {
             throw new IllegalArgumentException(shapeModel.getC2jName() + " event shape is not a member in any "
-                    + "request or response event shape");
+                                               + "request or response event shape");
         }
 
         EventStreamSpecHelper helper = new EventStreamSpecHelper(eventStream, intermediateModel);
 
         specBuilder.addSuperinterface(eventStreamClassName);
 
-        boolean usesLegacyScheme = useLegacyEventGenerationScheme(eventStream);
         Optional<MemberModel> legacyEvent = findLegacyGenerationEventWithShape(eventStream);
 
-        if (usesLegacyScheme && legacyEvent.isPresent()) {
+        if (eventGenerationMode == CustomizationConfig.LegacyEventGenerationMode.NO_ES_EVENT_IMPL && legacyEvent.isPresent()) {
             NamingStrategy namingStrategy = intermediateModel.getNamingStrategy();
             ClassName eventTypeEnum = helper.eventTypeEnumClassName();
             specBuilder.addMethod(MethodSpec.methodBuilder("sdkEventType")
-                       .addAnnotation(Override.class)
-                       .addModifiers(PUBLIC)
-                       .returns(eventTypeEnum)
-                       .addStatement("return $T.$N",
-                                     eventTypeEnum,
-                                     namingStrategy.getEnumValueName(legacyEvent.get().getName()))
-                       .build());
+                                            .addAnnotation(Override.class)
+                                            .addModifiers(PUBLIC)
+                                            .returns(eventTypeEnum)
+                                            .addStatement("return $T.$N",
+                                                          eventTypeEnum,
+                                                          namingStrategy.getEnumValueName(legacyEvent.get().getName()))
+                                            .build());
         }
 
         if (onOutput) {
@@ -254,9 +269,9 @@ private void addEventSupport(TypeSpec.Builder specBuilder, ShapeModel eventStrea
                 ClassName responseHandlerClass = poetExtensions.eventStreamResponseHandlerType(opModel);
 
                 MethodSpec.Builder acceptMethodSpec = acceptMethodSpec(modelClass, responseHandlerClass)
-                        .addAnnotation(Override.class);
+                    .addAnnotation(Override.class);
 
-                if (usesLegacyScheme) {
+                if (eventGenerationMode == CustomizationConfig.LegacyEventGenerationMode.NO_ES_EVENT_IMPL) {
                     acceptMethodSpec.addStatement("visitor.visit(this)");
                 } else {
                     // The class that represents the event type will be
@@ -846,7 +861,7 @@ private MethodSpec eventBuilderMethod(MemberModel event) {
 
         ClassName returnType;
 
-        if (specHelper.useLegacyGenerationScheme(event)) {
+        if (legacyEventGenerationMode(shapeModel) == CustomizationConfig.LegacyEventGenerationMode.NO_ES_EVENT_IMPL) {
             returnType = eventClassName.nestedClass("Builder");
         } else {
             ClassName baseClass = poetExtensions.getModelClass(event.getShape().getShapeName());
@@ -872,25 +887,14 @@ private MethodSpec addModifier(MethodSpec spec, Modifier modifier) {
         return spec.toBuilder().addModifiers(modifier).build();
     }
 
-    private boolean useLegacyEventGenerationScheme(ShapeModel eventStream) {
+    private CustomizationConfig.LegacyEventGenerationMode legacyEventGenerationMode(ShapeModel eventStream) {
         EventStreamSpecHelper helper = new EventStreamSpecHelper(eventStream, intermediateModel);
-        // This is hacky, but there's no better solution without
-        // extensive refactoring. We basically need to know if any of
-        // the *event types* within this even stream have this
-        // customization enabled, which requires knowing the
-        // MemberModel that has this given shape.
-        for (MemberModel member : eventStream.getMembers()) {
-            if (member.getShape().equals(shapeModel) && helper.useLegacyGenerationScheme(member)) {
-                return true;
-            }
-        }
-        return false;
+        return helper.legacyEventGenerationMode();
     }
 
     private Optional<MemberModel> findLegacyGenerationEventWithShape(ShapeModel eventStream) {
-        EventStreamSpecHelper helper = new EventStreamSpecHelper(eventStream, intermediateModel);
         for (MemberModel member : eventStream.getMembers()) {
-            if (member.getShape().equals(shapeModel) && helper.useLegacyGenerationScheme(member)) {
+            if (member.getShape().equals(shapeModel)) {
                 return Optional.ofNullable(member);
             }
         }

codegen/src/main/java/software/amazon/awssdk/codegen/poet/model/EventModelSpec.java

@@ -28,6 +28,7 @@
 import java.util.stream.Collectors;
 import javax.lang.model.element.Modifier;
 import software.amazon.awssdk.annotations.SdkInternalApi;
+import software.amazon.awssdk.codegen.model.config.customization.CustomizationConfig;
 import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
 import software.amazon.awssdk.codegen.model.intermediate.MemberModel;
 import software.amazon.awssdk.codegen.model.intermediate.OperationModel;
@@ -61,7 +62,9 @@ public EventModelSpec(MemberModel eventModel, ShapeModel eventStream, Intermedia
 
     @Override
     public TypeSpec poetSpec() {
-        return TypeSpec.classBuilder(className())
+        ClassName eventStreamClassName = poetExtensions.getModelClassFromShape(eventStream);
+
+        TypeSpec.Builder builder = TypeSpec.classBuilder(className())
                 .superclass(baseShapeModelSpec.className())
                 .addModifiers(Modifier.PUBLIC, Modifier.FINAL)
                 .addAnnotation(SdkInternalApi.class)
@@ -73,8 +76,12 @@ public TypeSpec poetSpec() {
                 .addMethod(builderMethod())
                 .addMethods(acceptMethods())
                 .addMethod(sdkEventTypeMethodSpec())
-                .addTypes(Arrays.asList(builderSpecs.builderInterface(), builderSpecs.beanStyleBuilder()))
-                .build();
+                .addTypes(Arrays.asList(builderSpecs.builderInterface(), builderSpecs.beanStyleBuilder()));
+
+        if (eventStreamSpecHelper.legacyEventGenerationMode() == CustomizationConfig.LegacyEventGenerationMode.DISABLED) {
+            builder.addSuperinterface(eventStreamClassName);
+        }
+        return builder.build();
     }
 
     private CodeBlock classJavadoc() {