Let override default response size limit

Still missing: Catch the C-library error to improve the error message.

src/objective-c/GRPCClient/GRPCCall+ChannelArg.h

@@ -43,7 +43,9 @@
  * Use the provided @c userAgentPrefix at the beginning of the HTTP User Agent string for all calls
  * to the specified @c host.
  */
-+ (void)setUserAgentPrefix:(NSString *)userAgentPrefix forHost:(NSString *)host;
++ (void)setUserAgentPrefix:(nonnull NSString *)userAgentPrefix forHost:(nonnull NSString *)host;
+
++ (void)setResponseSizeLimit:(NSUInteger)limit forHost:(nonnull NSString *)host;
 
 + (void)closeOpenConnections DEPRECATED_MSG_ATTRIBUTE("The API for this feature is experimental, "
                                                       "and might be removed or modified at any "

src/objective-c/GRPCClient/GRPCCall+ChannelArg.m

@@ -37,15 +37,16 @@
 
 @implementation GRPCCall (ChannelArg)
 
-+ (void)setUserAgentPrefix:(NSString *)userAgentPrefix forHost:(NSString *)host {
-  if (!host) {
-    [NSException raise:NSInvalidArgumentException
-                format:@"host and userAgentPrefix must be provided."];
-  }
++ (void)setUserAgentPrefix:(nonnull NSString *)userAgentPrefix forHost:(nonnull NSString *)host {
   GRPCHost *hostConfig = [GRPCHost hostWithAddress:host];
   hostConfig.userAgentPrefix = userAgentPrefix;
 }
 
++ (void)setResponseSizeLimit:(NSUInteger)limit forHost:(nonnull NSString *)host {
+  GRPCHost *hostConfig = [GRPCHost hostWithAddress:host];
+  hostConfig.responseSizeLimitOverride = @(limit);
+}
+
 + (void)closeOpenConnections {
   [GRPCHost flushChannelCache];
 }

src/objective-c/GRPCClient/GRPCCall+Tests.h

@@ -57,4 +57,10 @@
  * more than one invocation of the methods of this category.
  */
 + (void)useInsecureConnectionsForHost:(NSString *)host;
+
+/**
+ * Resets all host configurations to their default values, and flushes all connections from the
+ * cache.
+ */
++ (void)clearAllConfigurationsForTesting;
 @end

src/objective-c/GRPCClient/GRPCCall+Tests.m

@@ -61,4 +61,7 @@
   hostConfig.secure = NO;
 }
 
++ (void)clearAllConfigurationsForTesting {
+  [GRPCHost clearAllHostsForTesting];
+}
 @end

src/objective-c/GRPCClient/private/GRPCChannel.m

@@ -47,7 +47,7 @@
 #endif
 #import "GRPCCompletionQueue.h"
 
-void freeChannelArgs(grpc_channel_args *channel_args) {
+static void FreeChannelArgs(grpc_channel_args *channel_args) {
   for (size_t i = 0; i < channel_args->num_args; ++i) {
     grpc_arg *arg = &channel_args->args[i];
     gpr_free(arg->key);
@@ -65,7 +65,7 @@ void freeChannelArgs(grpc_channel_args *channel_args) {
  * value responds to @c @selector(intValue). Otherwise, an exception will be raised. The caller of
  * this function is responsible for calling @c freeChannelArgs on a non-NULL returned value.
  */
-grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
+static grpc_channel_args *BuildChannelArgs(NSDictionary *dictionary) {
   if (!dictionary) {
     return NULL;
   }
@@ -115,10 +115,12 @@ grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
   }
 
   if (self = [super init]) {
-    _channelArgs = buildChannelArgs(channelArgs);
+    _channelArgs = BuildChannelArgs(channelArgs);
     _host = [host copy];
-    _unmanagedChannel = grpc_cronet_secure_channel_create(cronetEngine, _host.UTF8String, _channelArgs,
-                                                     NULL);
+    _unmanagedChannel = grpc_cronet_secure_channel_create(cronetEngine,
+                                                          _host.UTF8String,
+                                                          _channelArgs,
+                                                          NULL);
   }
 
   return self;
@@ -138,7 +140,7 @@ grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
   }
 
   if (self = [super init]) {
-    _channelArgs = buildChannelArgs(channelArgs);
+    _channelArgs = BuildChannelArgs(channelArgs);
     _host = [host copy];
     if (secure) {
       _unmanagedChannel = grpc_secure_channel_create(credentials, _host.UTF8String, _channelArgs,
@@ -155,7 +157,7 @@ grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
   // TODO(jcanizales): Be sure to add a test with a server that closes the connection prematurely,
   // as in the past that made this call to crash.
   grpc_channel_destroy(_unmanagedChannel);
-  freeChannelArgs(_channelArgs);
+  FreeChannelArgs(_channelArgs);
 }
 
 #ifdef GRPC_COMPILE_WITH_CRONET

src/objective-c/GRPCClient/private/GRPCHost.h

@@ -42,6 +42,7 @@ struct grpc_channel_credentials;
 @interface GRPCHost : NSObject
 
 + (void)flushChannelCache;
++ (void)clearAllHostsForTesting;
 
 @property(nonatomic, readonly) NSString *address;
 @property(nonatomic, copy, nullable) NSString *userAgentPrefix;
@@ -53,6 +54,10 @@ struct grpc_channel_credentials;
 
 @property(nonatomic, copy, nullable) NSString *hostNameOverride;
 
+/** The default response size limit is 4MB. Set this to override that default. */
+@property(nonatomic, strong, nullable) NSNumber *responseSizeLimitOverride;
+
+
 - (nullable instancetype)init NS_UNAVAILABLE;
 /** Host objects initialized with the same address are the same. */
 + (nullable instancetype)hostWithAddress:(NSString *)address;

src/objective-c/GRPCClient/private/GRPCHost.m

@@ -49,7 +49,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 // TODO(jcanizales): Generate the version in a standalone header, from templates. Like
 // templates/src/core/surface/version.c.template .
-#define GRPC_OBJC_VERSION_STRING @"0.13.0"
+#define GRPC_OBJC_VERSION_STRING @"1.0.0-pre1"
 
 static NSMutableDictionary *kHostCache;
 
@@ -113,6 +113,12 @@ static NSMutableDictionary *kHostCache;
   }
 }
 
++ (void)clearAllHostsForTesting {
+  @synchronized (kHostCache) {
+    kHostCache = [NSMutableDictionary dictionary];
+  }
+}
+
 - (nullable grpc_call *)unmanagedCallWithPath:(NSString *)path
                               completionQueue:(GRPCCompletionQueue *)queue {
   GRPCChannel *channel;
@@ -209,6 +215,10 @@ static NSMutableDictionary *kHostCache;
   if (_secure && _hostNameOverride) {
     args[@GRPC_SSL_TARGET_NAME_OVERRIDE_ARG] = _hostNameOverride;
   }
+
+  if (_responseSizeLimitOverride) {
+    args[@GRPC_ARG_MAX_MESSAGE_LENGTH] = _responseSizeLimitOverride;
+  }
   return args;
 }
 

src/objective-c/tests/InteropTests.m

@@ -80,10 +80,6 @@
 
 #pragma mark Tests
 
-#ifdef GRPC_COMPILE_WITH_CRONET
-static cronet_engine *cronetEngine = NULL;
-#endif
-
 @implementation InteropTests {
   RMTTestService *_service;
 }
@@ -93,14 +89,17 @@ static cronet_engine *cronetEngine = NULL;
 }
 
 - (void)setUp {
+  self.continueAfterFailure = NO;
+
+  [GRPCCall clearAllConfigurationsForTesting];
+
   _service = self.class.host ? [RMTTestService serviceWithHost:self.class.host] : nil;
 #ifdef GRPC_COMPILE_WITH_CRONET
   if (cronetEngine == NULL) {
     // Cronet setup
     [Cronet setHttp2Enabled:YES];
     [Cronet start];
-    cronetEngine = [Cronet getGlobalEngine];
-    [GRPCCall useCronetWithEngine:cronetEngine];
+    [GRPCCall useCronetWithEngine:[Cronet getGlobalEngine]];
   }
 #endif
 }
@@ -146,6 +145,59 @@ static cronet_engine *cronetEngine = NULL;
   [self waitForExpectationsWithTimeout:16 handler:nil];
 }
 
+- (void)test4MBResponsesAreAccepted {
+  XCTAssertNotNil(self.class.host);
+  __weak XCTestExpectation *expectation = [self expectationWithDescription:@"MaxResponseSize"];
+
+  RMTSimpleRequest *request = [RMTSimpleRequest message];
+  const size_t kPayloadSize = 4 * 1024 * 1024 - 12; // 4MB - 12B of protobuf encoding overhead
+  request.responseSize = kPayloadSize;
+
+  [_service unaryCallWithRequest:request handler:^(RMTSimpleResponse *response, NSError *error) {
+    XCTAssertNil(error, @"Finished with unexpected error: %@", error);
+    XCTAssertEqual(response.payload.body.length, kPayloadSize);
+    [expectation fulfill];
+  }];
+
+  [self waitForExpectationsWithTimeout:16 handler:nil];
+}
+
+- (void)testResponsesOverMaxSizeFailWithActionableMessage {
+  XCTAssertNotNil(self.class.host);
+  __weak XCTestExpectation *expectation = [self expectationWithDescription:@"ResponseOverMaxSize"];
+
+  RMTSimpleRequest *request = [RMTSimpleRequest message];
+  const size_t kPayloadSize = 4 * 1024 * 1024 - 11; // 1B over max size (see above test)
+  request.responseSize = kPayloadSize;
+
+  [_service unaryCallWithRequest:request handler:^(RMTSimpleResponse *response, NSError *error) {
+    XCTAssertEqualObjects(error.localizedDescription, @"Max message size exceeded"); // TODO: Improve
+    [expectation fulfill];
+  }];
+
+  [self waitForExpectationsWithTimeout:16 handler:nil];
+}
+
+- (void)testResponsesOver4MBAreAcceptedIfOptedIn {
+  XCTAssertNotNil(self.class.host);
+  __weak XCTestExpectation *expectation =
+      [self expectationWithDescription:@"HigherResponseSizeLimit"];
+
+  RMTSimpleRequest *request = [RMTSimpleRequest message];
+  const size_t kPayloadSize = 5 * 1024 * 1024; // 5MB
+  request.responseSize = kPayloadSize;
+
+  [GRPCCall setResponseSizeLimit:6 * 1024 * 1024 forHost:self.class.host];
+
+  [_service unaryCallWithRequest:request handler:^(RMTSimpleResponse *response, NSError *error) {
+    XCTAssertNil(error, @"Finished with unexpected error: %@", error);
+    XCTAssertEqual(response.payload.body.length, kPayloadSize);
+    [expectation fulfill];
+  }];
+
+  [self waitForExpectationsWithTimeout:16 handler:nil];
+}
+
 - (void)testClientStreamingRPC {
   XCTAssertNotNil(self.class.host);
   __weak XCTestExpectation *expectation = [self expectationWithDescription:@"ClientStreaming"];