Separate GRPCProtoResponseHandler from GRPCResponseHandler

src/objective-c/GRPCClient/GRPCCall.h

@@ -157,10 +157,10 @@ extern id const kGRPCTrailersKey;
 - (void)receivedInitialMetadata:(NSDictionary *)initialMetadata;
 
 /**
- * Issued when a message is received from the server. The message may be raw data from the server
+ * Issued when a message is received from the server. The message is the raw data received from the
- * (when using \a GRPCCall2 directly) or deserialized proto object (when using \a ProtoRPC).
+ * server, with decompression and without proto deserialization.
  */
-- (void)receivedMessage:(id)message;
+- (void)receivedRawMessage:(id)message;
 
 /**
  * Issued when a call finished. If the call finished successfully, \a error is nil and \a

src/objective-c/GRPCClient/GRPCCall.m

@@ -236,9 +236,9 @@ const char *kCFStreamVarName = "grpc_cfstream";
 
 - (void)issueMessage:(id)message {
   id<GRPCResponseHandler> handler = self->_handler;
-  if ([handler respondsToSelector:@selector(receivedMessage:)]) {
+  if ([handler respondsToSelector:@selector(receivedRawMessage:)]) {
     dispatch_async(handler.dispatchQueue, ^{
-      [handler receivedMessage:message];
+      [handler receivedRawMessage:message];
     });
   }
 }

src/objective-c/ProtoRPC/ProtoRPC.h

@@ -23,6 +23,39 @@
 
 @class GPBMessage;
 
+/** An object can implement this protocol to receive responses from server from a call. */
+@protocol GRPCProtoResponseHandler <NSObject>
+
+@optional
+
+/** Issued when initial metadata is received from the server. */
+- (void)receivedInitialMetadata:(NSDictionary *)initialMetadata;
+
+/**
+ * Issued when a message is received from the server. The message is the deserialized proto object.
+ */
+- (void)receivedProtoMessage:(id)message;
+
+/**
+ * Issued when a call finished. If the call finished successfully, \a error is nil and \a
+ * trainingMetadata consists any trailing metadata received from the server. Otherwise, \a error
+ * is non-nil and contains the corresponding error information, including gRPC error codes and
+ * error descriptions.
+ */
+- (void)closedWithTrailingMetadata:(NSDictionary *)trailingMetadata error:(NSError *)error;
+
+@required
+
+/**
+ * All the responses must be issued to a user-provided dispatch queue. This property specifies the
+ * dispatch queue to be used for issuing the notifications. A serial queue should be provided if
+ * the order of responses (initial metadata, message, message, ..., message, trailing metadata)
+ * needs to be maintained.
+ */
+@property(atomic, readonly) dispatch_queue_t dispatchQueue;
+
+@end
+
 /** A unary-request RPC call with Protobuf. */
 @interface GRPCUnaryProtoCall : NSObject
 
@@ -36,7 +69,7 @@
  */
 - (instancetype)initWithRequestOptions:(GRPCRequestOptions *)requestOptions
                                message:(GPBMessage *)message
-                       responseHandler:(id<GRPCResponseHandler>)handler
+                       responseHandler:(id<GRPCProtoResponseHandler>)handler
                            callOptions:(GRPCCallOptions *)callOptions
                          responseClass:(Class)responseClass NS_DESIGNATED_INITIALIZER;
 
@@ -57,7 +90,7 @@
  * returned to users by methods of the generated service.
  */
 - (instancetype)initWithRequestOptions:(GRPCRequestOptions *)requestOptions
-                       responseHandler:(id<GRPCResponseHandler>)handler
+                       responseHandler:(id<GRPCProtoResponseHandler>)handler
                            callOptions:(GRPCCallOptions *)callOptions
                          responseClass:(Class)responseClass NS_DESIGNATED_INITIALIZER;
 

src/objective-c/ProtoRPC/ProtoRPC.m

@@ -33,7 +33,7 @@
 
 - (instancetype)initWithRequestOptions:(GRPCRequestOptions *)requestOptions
                                message:(GPBMessage *)message
-                       responseHandler:(id<GRPCResponseHandler>)handler
+                       responseHandler:(id<GRPCProtoResponseHandler>)handler
                            callOptions:(GRPCCallOptions *)callOptions
                          responseClass:(Class)responseClass {
   if ((self = [super init])) {
@@ -60,7 +60,7 @@
 
 @implementation GRPCStreamingProtoCall {
   GRPCRequestOptions *_requestOptions;
-  id<GRPCResponseHandler> _handler;
+  id<GRPCProtoResponseHandler> _handler;
   GRPCCallOptions *_callOptions;
   Class _responseClass;
 
@@ -69,7 +69,7 @@
 }
 
 - (instancetype)initWithRequestOptions:(GRPCRequestOptions *)requestOptions
-                       responseHandler:(id<GRPCResponseHandler>)handler
+                       responseHandler:(id<GRPCProtoResponseHandler>)handler
                            callOptions:(GRPCCallOptions *)callOptions
                          responseClass:(Class)responseClass {
   if ((self = [super init])) {
@@ -98,7 +98,8 @@
       _call = nil;
     }
     if (_handler) {
-      id<GRPCResponseHandler> handler = _handler;
+      id<GRPCProtoResponseHandler> handler = _handler;
+      if ([handler respondsToSelector:@selector(closedWithTrailingMetadata:error:)]) {
         dispatch_async(handler.dispatchQueue, ^{
           [handler closedWithTrailingMetadata:nil
                                         error:[NSError errorWithDomain:kGRPCErrorDomain
@@ -108,6 +109,7 @@
                                                                            @"Canceled by app"
                                                                          }]];
         });
+      }
       _handler = nil;
     }
   });
@@ -136,27 +138,33 @@
 
 - (void)receivedInitialMetadata:(NSDictionary *)initialMetadata {
   if (_handler) {
-    id<GRPCResponseHandler> handler = _handler;
+    id<GRPCProtoResponseHandler> handler = _handler;
+    if ([handler respondsToSelector:@selector(initialMetadata:)]) {
       dispatch_async(handler.dispatchQueue, ^{
         [handler receivedInitialMetadata:initialMetadata];
       });
     }
   }
+}
 
-- (void)receivedMessage:(NSData *)message {
+- (void)receivedRawMessage:(NSData *)message {
   if (_handler) {
-    id<GRPCResponseHandler> handler = _handler;
+    id<GRPCProtoResponseHandler> handler = _handler;
     NSError *error = nil;
     id parsed = [_responseClass parseFromData:message error:&error];
     if (parsed) {
+      if ([handler respondsToSelector:@selector(receivedProtoMessage:)]) {
         dispatch_async(handler.dispatchQueue, ^{
-        [handler receivedMessage:parsed];
+          [handler receivedProtoMessage:parsed];
         });
+      }
     } else {
+      if ([handler respondsToSelector:@selector(closedWithTrailingMetadata:error:)]) {
         dispatch_async(handler.dispatchQueue, ^{
           [handler closedWithTrailingMetadata:nil error:error];
         });
-      handler = nil;
+      }
+      _handler = nil;
       [_call cancel];
       _call = nil;
     }
@@ -165,17 +173,17 @@
 
 - (void)closedWithTrailingMetadata:(NSDictionary *)trailingMetadata error:(NSError *)error {
   if (_handler) {
-    id<GRPCResponseHandler> handler = _handler;
+    id<GRPCProtoResponseHandler> handler = _handler;
+    if ([handler respondsToSelector:@selector(closedWithTrailingMetadata:error:)]) {
       dispatch_async(handler.dispatchQueue, ^{
         [handler closedWithTrailingMetadata:trailingMetadata error:error];
       });
+    }
     _handler = nil;
   }
-  if (_call) {
   [_call cancel];
   _call = nil;
 }
-}
 
 - (dispatch_queue_t)dispatchQueue {
   return _dispatchQueue;

src/objective-c/tests/GRPCClientTests.m

@@ -120,7 +120,7 @@ static GRPCProtoMethod *kFullDuplexCallMethod;
   }
 }
 
-- (void)receivedMessage:(id)message {
+- (void)receivedProtoMessage:(id)message {
   if (_messageCallback) {
     _messageCallback(message);
   }

src/objective-c/tests/InteropTests.m

@@ -75,7 +75,7 @@ BOOL isRemoteInteropTest(NSString *host) {
 }
 
 // Convenience class to use blocks as callbacks
-@interface InteropTestsBlockCallbacks : NSObject<GRPCResponseHandler>
+@interface InteropTestsBlockCallbacks : NSObject<GRPCProtoResponseHandler>
 
 - (instancetype)initWithInitialMetadataCallback:(void (^)(NSDictionary *))initialMetadataCallback
                                 messageCallback:(void (^)(id))messageCallback
@@ -108,7 +108,7 @@ BOOL isRemoteInteropTest(NSString *host) {
   }
 }
 
-- (void)receivedMessage:(id)message {
+- (void)receivedProtoMessage:(id)message {
   if (_messageCallback) {
     _messageCallback(message);
   }