text: /*
   *
   * Copyright 2015 gRPC authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License 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.
   *
   */
  
  #import <Foundation/Foundation.h>
  
  #include <grpc/grpc.h>
  
  @class GRPCCompletionQueue;
  struct grpc_channel_credentials;
  
  
  /**
   * Each separate instance of this class represents at least one TCP connection to the provided host.
   */
  @interface GRPCChannel : NSObject
  
  @property(nonatomic, readonly, nonnull) struct grpc_channel *unmanagedChannel;
  
  - (nullable instancetype)init NS_UNAVAILABLE;
  
  /**
   * Creates a secure channel to the specified @c host using default credentials and channel
   * arguments. If certificates could not be found to create a secure channel, then @c nil is
   * returned.
   */
  + (nullable GRPCChannel *)secureChannelWithHost:(nonnull NSString *)host;
  
  /**
   * Creates a secure channel to the specified @c host using Cronet as a transport mechanism.
   */
  #ifdef GRPC_COMPILE_WITH_CRONET
  + (nullable GRPCChannel *)secureCronetChannelWithHost:(nonnull NSString *)host
                                            channelArgs:(nonnull NSDictionary *)channelArgs;
  #endif
  /**
   * Creates a secure channel to the specified @c host using the specified @c credentials and
   * @c channelArgs. Only in tests should @c GRPC_SSL_TARGET_NAME_OVERRIDE_ARG channel arg be set.
   */
  + (nonnull GRPCChannel *)secureChannelWithHost:(nonnull NSString *)host
      credentials:(nonnull struct grpc_channel_credentials *)credentials
      channelArgs:(nullable NSDictionary *)channelArgs;
  
  /**
   * Creates an insecure channel to the specified @c host using the specified @c channelArgs.
   */
  + (nonnull GRPCChannel *)insecureChannelWithHost:(nonnull NSString *)host
                                       channelArgs:(nullable NSDictionary *)channelArgs;
  
  - (nullable grpc_call *)unmanagedCallWithPath:(nonnull NSString *)path
                                     serverName:(nonnull NSString *)serverName
                                completionQueue:(nonnull GRPCCompletionQueue *)queue;
  @end
  