Makes GRPCChannel a cluster class of secure and unsecured.

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

@@ -45,6 +45,7 @@ struct grpc_channel;
 // Convenience constructor to allow for reuse of connections.
 + (instancetype)channelToHost:(NSString *)host;
 
-// Designated initializer
-- (instancetype)initWithHost:(NSString *)host;
+- (instancetype)initWithHost:(NSString *)host NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)initWithChannel:(struct grpc_channel *)unmanagedChannel NS_DESIGNATED_INITIALIZER;
 @end

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

@@ -33,7 +33,10 @@
 
 #import "GRPCChannel.h"
 
-#import <grpc/grpc.h>
+#include <grpc/grpc.h>
+
+#import "GRPCSecureChannel.h"
+#import "GRPCUnsecuredChannel.h"
 
 @implementation GRPCChannel
 
@@ -46,13 +49,25 @@
   return [self initWithHost:nil];
 }
 
-// Designated initializer
 - (instancetype)initWithHost:(NSString *)host {
-  if (!host) {
-    [NSException raise:NSInvalidArgumentException format:@"Host can't be nil."];
+  NSURL *hostURL = [NSURL URLWithString:host];
+  if (!hostURL) {
+    [NSException raise:NSInvalidArgumentException format:@"Invalid URL: %@", host];
+  }
+  if (!hostURL.scheme || [hostURL.scheme isEqualToString:@"https"]) {
+    return [[GRPCSecureChannel alloc] initWithHost:host];
+  }
+  if ([hostURL.scheme isEqualToString:@"http"]) {
+    return [[GRPCUnsecuredChannel alloc] initWithHost:host];
   }
+  [NSException raise:NSInvalidArgumentException
+              format:@"URL scheme %@ isn't supported.", hostURL.scheme];
+  return nil; // silence warning.
+}
+
+- (instancetype)initWithChannel:(struct grpc_channel *)unmanagedChannel {
   if ((self = [super init])) {
-    _unmanagedChannel = grpc_channel_create(host.UTF8String, NULL);
+    _unmanagedChannel = unmanagedChannel;
   }
   return self;
 }

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

+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#import "GRPCChannel.h"
+
+@interface GRPCSecureChannel : GRPCChannel
+
+@end

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

+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#import "GRPCSecureChannel.h"
+
+#import <grpc/grpc_security.h>
+
+@implementation GRPCSecureChannel
+
+- (instancetype)initWithHost:(NSString *)host {
+  // TODO(jcanizales): Get the certificates here.
+  grpc_credentials *credentials = grpc_ssl_credentials_create(NULL, NULL);
+  return (self = [super initWithChannel:grpc_secure_channel_create(credentials,
+                                                                   host.UTF8String,
+                                                                   NULL)]);
+}
+
+@end

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

+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#import "GRPCChannel.h"
+
+@interface GRPCUnsecuredChannel : GRPCChannel
+
+@end

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

+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#import "GRPCUnsecuredChannel.h"
+
+#include <grpc/grpc.h>
+
+@implementation GRPCUnsecuredChannel
+
+- (instancetype)initWithHost:(NSString *)host {
+  return (self = [super initWithChannel:grpc_channel_create(host.UTF8String, NULL)]);
+}
+
+@end