feat(generator): wire transport stub delegation to resumable upload stubs (#14322)

Wires generated transport stubs (`GrpcServiceStub`,
`HttpJsonServiceStub`) to delegate resumable upload methods to the
internal HTTP upload stub, and excludes upload RPCs from the main stubs'
method descriptors and callables.

Author: whowes

sdk-platform-java/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/Composer.java

@@ -29,10 +29,12 @@
 import com.google.api.generator.gapic.composer.grpcrest.HttpJsonServiceClientTestClassComposer;
 import com.google.api.generator.gapic.composer.resourcename.ResourceNameHelperClassComposer;
 import com.google.api.generator.gapic.composer.rest.HttpJsonServiceCallableFactoryClassComposer;
+import com.google.api.generator.gapic.composer.rest.HttpJsonServiceResumableUploadStubClassComposer;
 import com.google.api.generator.gapic.composer.rest.HttpJsonServiceStubClassComposer;
 import com.google.api.generator.gapic.model.GapicClass;
 import com.google.api.generator.gapic.model.GapicContext;
 import com.google.api.generator.gapic.model.GapicPackageInfo;
+import com.google.api.generator.gapic.model.Method;
 import com.google.api.generator.gapic.model.ReflectConfig;
 import com.google.api.generator.gapic.model.Sample;
 import com.google.api.generator.gapic.model.Service;
@@ -91,6 +93,11 @@ public static List<GapicClass> generateStubClasses(GapicContext context) {
         .services()
         .forEach(
             s -> {
+              if (s.methods().stream().anyMatch(Method::isResumableUpload)) {
+                clazzes.add(
+                    HttpJsonServiceResumableUploadStubClassComposer.instance()
+                        .generate(context, s));
+              }
               if (context.transport() == Transport.REST) {
                 clazzes.add(
                     com.google.api.generator.gapic.composer.rest.ServiceStubClassComposer.instance()

sdk-platform-java/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubClassComposer.java

@@ -21,6 +21,7 @@
 import com.google.api.gax.rpc.ClientStreamingCallable;
 import com.google.api.gax.rpc.LongRunningClient;
 import com.google.api.gax.rpc.OperationCallable;
+import com.google.api.gax.rpc.ResumableUploadCallable;
 import com.google.api.gax.rpc.ServerStreamingCallable;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.api.generator.engine.ast.AnnotationNode;
@@ -162,22 +163,7 @@ private MethodDefinition createCallableGetter(Method method, TypeStore typeStore
 
   private MethodDefinition createCallableGetterHelper(
       Method method, TypeStore typeStore, boolean isLroCallable, boolean isPaged) {
-    TypeNode returnType;
-    switch (method.stream()) {
-      case CLIENT:
-        returnType = typeStore.get("ClientStreamingCallable");
-        break;
-      case SERVER:
-        returnType = typeStore.get("ServerStreamingCallable");
-        break;
-      case BIDI:
-        returnType = typeStore.get("BidiStreamingCallable");
-        break;
-      case NONE:
-      // Fall through.
-      default:
-        returnType = typeStore.get(isLroCallable ? "OperationCallable" : "UnaryCallable");
-    }
+    TypeNode returnType = getCallableType(method, typeStore, isLroCallable);
 
     String methodName =
         String.format(
@@ -270,6 +256,7 @@ private static TypeStore createTypes(Service service, Map<String, Message> messa
             Generated.class,
             Operation.class,
             OperationCallable.class,
+            ResumableUploadCallable.class,
             ServerStreamingCallable.class,
             UnaryCallable.class,
             UnsupportedOperationException.class,
@@ -328,4 +315,22 @@ protected MethodDefinition createOperationsStubGetterMethodDefinition(
                         .build())))
         .build();
   }
+
+  private static TypeNode getCallableType(
+      Method method, TypeStore typeStore, boolean isLroCallable) {
+    if (method.isResumableUpload()) {
+      return typeStore.get("ResumableUploadCallable");
+    }
+    switch (method.stream()) {
+      case CLIENT:
+        return typeStore.get("ClientStreamingCallable");
+      case SERVER:
+        return typeStore.get("ServerStreamingCallable");
+      case BIDI:
+        return typeStore.get("BidiStreamingCallable");
+      case NONE:
+      default:
+        return typeStore.get(isLroCallable ? "OperationCallable" : "UnaryCallable");
+    }
+  }
 }