src/objective-c/GRPCClient/GRPCCallOptions.h - platform/external/grpc-grpc - Git at Google

 /*
  *
  * Copyright 2018 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>

 #import "GRPCTypes.h"

 NS_ASSUME_NONNULL_BEGIN

 @protocol GRPCInterceptorFactory;

 /**
  * Immutable user configurable options for a gRPC call.
  * Caller can obtain a mutable copy of type \b GRPCMutableCallOptions by calling [option
  * mutableCopy]
  */
 @interface GRPCCallOptions : NSObject <NSCopying, NSMutableCopying>

 // Call parameters
 /**
  * The authority for the RPC. If nil, the default authority will be used.
  *
  * Note: This property does not have effect on Cronet transport and will be ignored.
  * Note: This property cannot be used to validate a self-signed server certificate. It control the
  *       :authority header field of the call and performs an extra check that server's certificate
  *       matches the :authority header.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *serverAuthority;

 /**
  * The timeout for the RPC call in seconds. If set to 0, the call will not timeout. If set to
  * positive, the gRPC call returns with status GRPCErrorCodeDeadlineExceeded if it is not completed
  * within \a timeout seconds. A negative value is not allowed.
  */
 @property(nonatomic, readonly) NSTimeInterval timeout;

 /**
  * Enable flow control of a gRPC call. The option is default to NO. If set to YES, writeData: method
  * should only be called at most once before a didWriteData callback is issued, and
  * receiveNextMessage: must be called each time before gRPC call issues a didReceiveMessage
  * callback.
  */
 @property(nonatomic, readonly) BOOL flowControlEnabled;

 /**
  * An array of interceptor factories. When a call starts, interceptors are created
  * by these factories and chained together with the same order as the factories in
  * this array. This parameter should not be modified by any interceptor and will
  * not take effect if done so.
  */
 @property(nonatomic, copy, readonly) NSArray<id<GRPCInterceptorFactory>> *interceptorFactories;

 // OAuth2 parameters. Users of gRPC may specify one of the following two parameters.

 /**
  * The OAuth2 access token string. The string is prefixed with "Bearer " then used as value of the
  * request's "authorization" header field. This parameter should not be used simultaneously with
  * \a authTokenProvider.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *oauth2AccessToken;

 /**
  * The interface to get the OAuth2 access token string. gRPC will attempt to acquire token when
  * initiating the call. This parameter should not be used simultaneously with \a oauth2AccessToken.
  */
 @property(nonatomic, readonly, nullable) id<GRPCAuthorizationProtocol> authTokenProvider;

 /**
  * Initial metadata key-value pairs that should be included in the request.
  * Dictionary key is of type NSString, value should be either NSString or NSData containing binary
  * bytes data.
  */
 @property(nonatomic, copy, readonly, nullable) GRPCMetadataDictionary *initialMetadata;

 // Channel parameters; take into account of channel signature.

 /**
  * Custom string that is prefixed to a request's user-agent header field before gRPC's internal
  * user-agent string.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *userAgentPrefix;

 /**
  * Custom string that is suffixed to a request's user-agent header field after gRPC's internal
  * user-agent string.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *userAgentSuffix;

 /**
  * The size limit for the response received from server. If it is exceeded, an error with status
  * code GRPCErrorCodeResourceExhausted is returned.
  */
 @property(nonatomic, readonly) NSUInteger responseSizeLimit;

 /**
  * The compression algorithm to be used by the gRPC call. For more details refer to
  * https://github.com/grpc/grpc/blob/master/doc/compression.md
  */
 @property(nonatomic, readonly) GRPCCompressionAlgorithm compressionAlgorithm;

 /**
  * Enable/Disable gRPC call's retry feature. The default is enabled. For details of this feature
  * refer to
  * https://github.com/grpc/proposal/blob/master/A6-client-retries.md
  */
 @property(nonatomic, readonly) BOOL retryEnabled;

 /**
  * Maximum interval in seconds between two consecutive retries.
  * Internal-only property used for GTMSessionFetcher transport retry policy.
  */
 @property(nonatomic, readonly) NSTimeInterval maxRetryInterval;

 /**
  * Minimum interval in seconds between two consecutive retries.
  * Internal-only property used for GTMSessionFetcher transport retry policy.
  */
 @property(nonatomic, readonly) NSTimeInterval minRetryInterval;

 /**
  * Multiplier used to increase the interval between retries.
  * Internal-only property used for GTMSessionFetcher transport retry policy.
  */
 @property(readonly) double retryFactor;

 // HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
 // PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
 // call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
 // Negative values are not allowed.
 @property(nonatomic, readonly) NSTimeInterval keepaliveInterval;
 @property(nonatomic, readonly) NSTimeInterval keepaliveTimeout;

 // Parameters for connection backoff. Negative values are not allowed.
 // For details of gRPC's backoff behavior, refer to
 // https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
 @property(nonatomic, readonly) NSTimeInterval connectMinTimeout;
 @property(nonatomic, readonly) NSTimeInterval connectInitialBackoff;
 @property(nonatomic, readonly) NSTimeInterval connectMaxBackoff;

 /**
  * Specify channel args to be used for this call. For a list of channel args available, see
  * grpc/grpc_types.h
  */
 @property(nonatomic, copy, readonly, nullable) GRPCMetadataDictionary *additionalChannelArgs;

 // Parameters for SSL authentication.

 /**
  * PEM format root certifications that is trusted. If set to nil, gRPC uses a list of default
  * root certificates.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *PEMRootCertificates;

 /**
  * PEM format private key for client authentication, if required by the server.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *PEMPrivateKey;

 /**
  * PEM format certificate chain for client authentication, if required by the server.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *PEMCertificateChain;

 /**
  * Deprecated: this option is deprecated. Please use the property \a transport
  * instead.
  *
  * Select the transport type to be used for this call.
  */
 @property(nonatomic, readonly) GRPCTransportType transportType;

 /**
  * The transport to be used for this call. Users may choose a native transport
  * identifier defined in \a GRPCTransport or provided by a non-native transport
  * implementation. If the option is left to be NULL, gRPC will use its default
  * transport.
  *
  * This is currently an experimental option.
  */
 @property(nonatomic, readonly) GRPCTransportID transport;

 /**
  * Override the hostname during the TLS hostname validation process.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *hostNameOverride;

 /**
  * A string that specify the domain where channel is being cached. Channels with different domains
  * will not get cached to the same connection.
  */
 @property(nonatomic, copy, readonly, nullable) NSString *channelPoolDomain;

 /**
  * Channel id allows control of channel caching within a channelPoolDomain. A call with a unique
  * channelID will create a new channel (connection) instead of reusing an existing one. Multiple
  * calls in the same channelPoolDomain using identical channelID are allowed to share connection
  * if other channel options are also the same.
  */
 @property(nonatomic, readonly) NSUInteger channelID;

 /**
  * Hash for channel options.
  */
 @property(nonatomic, readonly) NSUInteger channelOptionsHash;

 /**
  * Return if the channel options are equal to another object.
  */
 - (BOOL)hasChannelOptionsEqualTo:(GRPCCallOptions *)callOptions;

 @end

 /**
  * Mutable user configurable options for a gRPC call.
  * Caller can obtain an immutable copy of type \b GRPCCallOptions by calling [option copy]
  */
 @interface GRPCMutableCallOptions : GRPCCallOptions <NSCopying, NSMutableCopying>

 // Call parameters
 /**
  * The authority for the RPC. If nil, the default authority will be used.
  *
  * Note: This property does not have effect on Cronet transport and will be ignored.
  * Note: This property cannot be used to validate a self-signed server certificate. It control the
  *       :authority header field of the call and performs an extra check that server's certificate
  *       matches the :authority header.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *serverAuthority;

 /**
  * The timeout for the RPC call in seconds. If set to 0, the call will not timeout. If set to
  * positive, the gRPC call returns with status GRPCErrorCodeDeadlineExceeded if it is not completed
  * within \a timeout seconds. Negative value is invalid; setting the parameter to negative value
  * will reset the parameter to 0.
  */
 @property(nonatomic, readwrite) NSTimeInterval timeout;

 /**
  * Enable flow control of a gRPC call. The option is default to NO. If set to YES, writeData: method
  * should only be called at most once before a didWriteData callback is issued, and
  * receiveNextMessage: must be called each time before gRPC call can issue a didReceiveMessage
  * callback.
  *
  * If writeData: method is called more than once before issuance of a didWriteData callback, gRPC
  * will continue to queue the message and write them to gRPC core in order. However, the user
  * assumes their own responsibility of flow control by keeping tracking of the pending writes in
  * the call.
  */
 @property(nonatomic, readwrite) BOOL flowControlEnabled;

 /**
  * An array of interceptor factories. When a call starts, interceptors are created
  * by these factories and chained together with the same order as the factories in
  * this array. This parameter should not be modified by any interceptor and will
  * not take effect if done so.
  */
 @property(nonatomic, copy, readwrite) NSArray<id<GRPCInterceptorFactory>> *interceptorFactories;

 // OAuth2 parameters. Users of gRPC may specify one of the following two parameters.

 /**
  * The OAuth2 access token string. The string is prefixed with "Bearer " then used as value of the
  * request's "authorization" header field. This parameter should not be used simultaneously with
  * \a authTokenProvider.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *oauth2AccessToken;

 /**
  * The interface to get the OAuth2 access token string. gRPC will attempt to acquire token when
  * initiating the call. This parameter should not be used simultaneously with \a oauth2AccessToken.
  */
 @property(nonatomic, readwrite, nullable) id<GRPCAuthorizationProtocol> authTokenProvider;

 /**
  * Initial metadata key-value pairs that should be included in the request.
  * Dictionary key is of type NSString, value should be either NSString or NSData containing binary
  * bytes data.
  */
 @property(nonatomic, nonatomic, copy, readwrite, nullable) GRPCMetadataDictionary *initialMetadata;

 // Channel parameters; take into account of channel signature.

 /**
  * Custom string that is prefixed to a request's user-agent header field before gRPC's internal
  * user-agent string.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *userAgentPrefix;

 /**
  * Custom string that is suffixed to a request's user-agent header field after gRPC's internal
  * user-agent string.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *userAgentSuffix;

 /**
  * The size limit for the response received from server. If it is exceeded, an error with status
  * code GRPCErrorCodeResourceExhausted is returned.
  */
 @property(nonatomic, readwrite) NSUInteger responseSizeLimit;

 /**
  * The compression algorithm to be used by the gRPC call. For more details refer to
  * https://github.com/grpc/grpc/blob/master/doc/compression.md
  */
 @property(nonatomic, readwrite) GRPCCompressionAlgorithm compressionAlgorithm;

 /**
  * Enable/Disable gRPC call's retry feature. The default is enabled. For details of this feature
  * refer to
  * https://github.com/grpc/proposal/blob/master/A6-client-retries.md
  */
 @property(nonatomic, readwrite) BOOL retryEnabled;

 /**
  * Maximum interval in seconds between two consecutive retries. Pass 0 to use default.
  * Internal-only property used for GTMSessionFetcher transport retry policy.
  */
 @property(nonatomic, readwrite) NSTimeInterval maxRetryInterval;

 /**
  * Minimum interval in seconds between two consecutive retries. Pass 0 to use default.
  * Internal-only property used for GTMSessionFetcher transport retry policy.
  */
 @property(nonatomic, readwrite) NSTimeInterval minRetryInterval;

 /**
  * Multiplier used to increase the interval between retries. Pass 0 to use default.
  * Internal-only property used for GTMSessionFetcher transport retry policy.
  */
 @property(nonatomic, readwrite) double retryFactor;

 // HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
 // PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
 // call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
 // Negative values are invalid; setting these parameters to negative value will reset the
 // corresponding parameter to 0.
 @property(nonatomic, readwrite) NSTimeInterval keepaliveInterval;
 @property(nonatomic, readwrite) NSTimeInterval keepaliveTimeout;

 // Parameters for connection backoff. Negative value is invalid; setting the parameters to negative
 // value will reset corresponding parameter to 0.
 // For details of gRPC's backoff behavior, refer to
 // https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
 @property(nonatomic, readwrite) NSTimeInterval connectMinTimeout;
 @property(nonatomic, readwrite) NSTimeInterval connectInitialBackoff;
 @property(nonatomic, readwrite) NSTimeInterval connectMaxBackoff;

 /**
  * Specify channel args to be used for this call. For a list of channel args available, see
  * grpc/grpc_types.h
  */
 @property(nonatomic, copy, readwrite, nullable) GRPCMetadataDictionary *additionalChannelArgs;

 // Parameters for SSL authentication.

 /**
  * PEM format root certifications that is trusted. If set to nil, gRPC uses a list of default
  * root certificates.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *PEMRootCertificates;

 /**
  * PEM format private key for client authentication, if required by the server.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *PEMPrivateKey;

 /**
  * PEM format certificate chain for client authentication, if required by the server.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *PEMCertificateChain;

 /**
  * Deprecated: this option is deprecated. Please use the property \a transport
  * instead.
  *
  * Select the transport type to be used for this call.
  */
 @property(nonatomic, readwrite) GRPCTransportType transportType;

 /**
  * The transport to be used for this call. Users may choose a native transport
  * identifier defined in \a GRPCTransport or provided by a non-native ttransport
  * implementation. If the option is left to be NULL, gRPC will use its default
  * transport.
  *
  * An interceptor must not change the value of this option.
  */
 @property(nonatomic, readwrite) GRPCTransportID transport;

 /**
  * Override the hostname during the TLS hostname validation process.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *hostNameOverride;

 /**
  * A string that specify the domain where channel is being cached. Channels with different domains
  * will not get cached to the same channel. For example, a gRPC example app may use the channel pool
  * domain 'io.grpc.example' so that its calls do not reuse the channel created by other modules in
  * the same process.
  */
 @property(nonatomic, copy, readwrite, nullable) NSString *channelPoolDomain;

 /**
  * Channel id allows a call to force creating a new channel (connection) rather than using a cached
  * channel. Calls using distinct channelID's will not get cached to the same channel.
  */
 @property(nonatomic, readwrite) NSUInteger channelID;

 @end

 NS_ASSUME_NONNULL_END
	/*
	*
	* Copyright 2018 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>

	#import "GRPCTypes.h"

	NS_ASSUME_NONNULL_BEGIN

	@protocol GRPCInterceptorFactory;

	/**
	* Immutable user configurable options for a gRPC call.
	* Caller can obtain a mutable copy of type \b GRPCMutableCallOptions by calling [option
	* mutableCopy]
	*/
	@interface GRPCCallOptions : NSObject <NSCopying, NSMutableCopying>

	// Call parameters
	/**
	* The authority for the RPC. If nil, the default authority will be used.
	*
	* Note: This property does not have effect on Cronet transport and will be ignored.
	* Note: This property cannot be used to validate a self-signed server certificate. It control the
	* :authority header field of the call and performs an extra check that server's certificate
	* matches the :authority header.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *serverAuthority;

	/**
	* The timeout for the RPC call in seconds. If set to 0, the call will not timeout. If set to
	* positive, the gRPC call returns with status GRPCErrorCodeDeadlineExceeded if it is not completed
	* within \a timeout seconds. A negative value is not allowed.
	*/
	@property(nonatomic, readonly) NSTimeInterval timeout;

	/**
	* Enable flow control of a gRPC call. The option is default to NO. If set to YES, writeData: method
	* should only be called at most once before a didWriteData callback is issued, and
	* receiveNextMessage: must be called each time before gRPC call issues a didReceiveMessage
	* callback.
	*/
	@property(nonatomic, readonly) BOOL flowControlEnabled;

	/**
	* An array of interceptor factories. When a call starts, interceptors are created
	* by these factories and chained together with the same order as the factories in
	* this array. This parameter should not be modified by any interceptor and will
	* not take effect if done so.
	*/
	@property(nonatomic, copy, readonly) NSArray<id<GRPCInterceptorFactory>> *interceptorFactories;

	// OAuth2 parameters. Users of gRPC may specify one of the following two parameters.

	/**
	* The OAuth2 access token string. The string is prefixed with "Bearer " then used as value of the
	* request's "authorization" header field. This parameter should not be used simultaneously with
	* \a authTokenProvider.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *oauth2AccessToken;

	/**
	* The interface to get the OAuth2 access token string. gRPC will attempt to acquire token when
	* initiating the call. This parameter should not be used simultaneously with \a oauth2AccessToken.
	*/
	@property(nonatomic, readonly, nullable) id<GRPCAuthorizationProtocol> authTokenProvider;

	/**
	* Initial metadata key-value pairs that should be included in the request.
	* Dictionary key is of type NSString, value should be either NSString or NSData containing binary
	* bytes data.
	*/
	@property(nonatomic, copy, readonly, nullable) GRPCMetadataDictionary *initialMetadata;

	// Channel parameters; take into account of channel signature.

	/**
	* Custom string that is prefixed to a request's user-agent header field before gRPC's internal
	* user-agent string.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *userAgentPrefix;

	/**
	* Custom string that is suffixed to a request's user-agent header field after gRPC's internal
	* user-agent string.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *userAgentSuffix;

	/**
	* The size limit for the response received from server. If it is exceeded, an error with status
	* code GRPCErrorCodeResourceExhausted is returned.
	*/
	@property(nonatomic, readonly) NSUInteger responseSizeLimit;

	/**
	* The compression algorithm to be used by the gRPC call. For more details refer to
	* https://github.com/grpc/grpc/blob/master/doc/compression.md
	*/
	@property(nonatomic, readonly) GRPCCompressionAlgorithm compressionAlgorithm;

	/**
	* Enable/Disable gRPC call's retry feature. The default is enabled. For details of this feature
	* refer to
	* https://github.com/grpc/proposal/blob/master/A6-client-retries.md
	*/
	@property(nonatomic, readonly) BOOL retryEnabled;

	/**
	* Maximum interval in seconds between two consecutive retries.
	* Internal-only property used for GTMSessionFetcher transport retry policy.
	*/
	@property(nonatomic, readonly) NSTimeInterval maxRetryInterval;

	/**
	* Minimum interval in seconds between two consecutive retries.
	* Internal-only property used for GTMSessionFetcher transport retry policy.
	*/
	@property(nonatomic, readonly) NSTimeInterval minRetryInterval;

	/**
	* Multiplier used to increase the interval between retries.
	* Internal-only property used for GTMSessionFetcher transport retry policy.
	*/
	@property(readonly) double retryFactor;

	// HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
	// PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
	// call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
	// Negative values are not allowed.
	@property(nonatomic, readonly) NSTimeInterval keepaliveInterval;
	@property(nonatomic, readonly) NSTimeInterval keepaliveTimeout;

	// Parameters for connection backoff. Negative values are not allowed.
	// For details of gRPC's backoff behavior, refer to
	// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
	@property(nonatomic, readonly) NSTimeInterval connectMinTimeout;
	@property(nonatomic, readonly) NSTimeInterval connectInitialBackoff;
	@property(nonatomic, readonly) NSTimeInterval connectMaxBackoff;

	/**
	* Specify channel args to be used for this call. For a list of channel args available, see
	* grpc/grpc_types.h
	*/
	@property(nonatomic, copy, readonly, nullable) GRPCMetadataDictionary *additionalChannelArgs;

	// Parameters for SSL authentication.

	/**
	* PEM format root certifications that is trusted. If set to nil, gRPC uses a list of default
	* root certificates.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *PEMRootCertificates;

	/**
	* PEM format private key for client authentication, if required by the server.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *PEMPrivateKey;

	/**
	* PEM format certificate chain for client authentication, if required by the server.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *PEMCertificateChain;

	/**
	* Deprecated: this option is deprecated. Please use the property \a transport
	* instead.
	*
	* Select the transport type to be used for this call.
	*/
	@property(nonatomic, readonly) GRPCTransportType transportType;

	/**
	* The transport to be used for this call. Users may choose a native transport
	* identifier defined in \a GRPCTransport or provided by a non-native transport
	* implementation. If the option is left to be NULL, gRPC will use its default
	* transport.
	*
	* This is currently an experimental option.
	*/
	@property(nonatomic, readonly) GRPCTransportID transport;

	/**
	* Override the hostname during the TLS hostname validation process.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *hostNameOverride;

	/**
	* A string that specify the domain where channel is being cached. Channels with different domains
	* will not get cached to the same connection.
	*/
	@property(nonatomic, copy, readonly, nullable) NSString *channelPoolDomain;

	/**
	* Channel id allows control of channel caching within a channelPoolDomain. A call with a unique
	* channelID will create a new channel (connection) instead of reusing an existing one. Multiple
	* calls in the same channelPoolDomain using identical channelID are allowed to share connection
	* if other channel options are also the same.
	*/
	@property(nonatomic, readonly) NSUInteger channelID;

	/**
	* Hash for channel options.
	*/
	@property(nonatomic, readonly) NSUInteger channelOptionsHash;

	/**
	* Return if the channel options are equal to another object.
	*/
	- (BOOL)hasChannelOptionsEqualTo:(GRPCCallOptions *)callOptions;

	@end

	/**
	* Mutable user configurable options for a gRPC call.
	* Caller can obtain an immutable copy of type \b GRPCCallOptions by calling [option copy]
	*/
	@interface GRPCMutableCallOptions : GRPCCallOptions <NSCopying, NSMutableCopying>

	// Call parameters
	/**
	* The authority for the RPC. If nil, the default authority will be used.
	*
	* Note: This property does not have effect on Cronet transport and will be ignored.
	* Note: This property cannot be used to validate a self-signed server certificate. It control the
	* :authority header field of the call and performs an extra check that server's certificate
	* matches the :authority header.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *serverAuthority;

	/**
	* The timeout for the RPC call in seconds. If set to 0, the call will not timeout. If set to
	* positive, the gRPC call returns with status GRPCErrorCodeDeadlineExceeded if it is not completed
	* within \a timeout seconds. Negative value is invalid; setting the parameter to negative value
	* will reset the parameter to 0.
	*/
	@property(nonatomic, readwrite) NSTimeInterval timeout;

	/**
	* Enable flow control of a gRPC call. The option is default to NO. If set to YES, writeData: method
	* should only be called at most once before a didWriteData callback is issued, and
	* receiveNextMessage: must be called each time before gRPC call can issue a didReceiveMessage
	* callback.
	*
	* If writeData: method is called more than once before issuance of a didWriteData callback, gRPC
	* will continue to queue the message and write them to gRPC core in order. However, the user
	* assumes their own responsibility of flow control by keeping tracking of the pending writes in
	* the call.
	*/
	@property(nonatomic, readwrite) BOOL flowControlEnabled;

	/**
	* An array of interceptor factories. When a call starts, interceptors are created
	* by these factories and chained together with the same order as the factories in
	* this array. This parameter should not be modified by any interceptor and will
	* not take effect if done so.
	*/
	@property(nonatomic, copy, readwrite) NSArray<id<GRPCInterceptorFactory>> *interceptorFactories;

	// OAuth2 parameters. Users of gRPC may specify one of the following two parameters.

	/**
	* The OAuth2 access token string. The string is prefixed with "Bearer " then used as value of the
	* request's "authorization" header field. This parameter should not be used simultaneously with
	* \a authTokenProvider.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *oauth2AccessToken;

	/**
	* The interface to get the OAuth2 access token string. gRPC will attempt to acquire token when
	* initiating the call. This parameter should not be used simultaneously with \a oauth2AccessToken.
	*/
	@property(nonatomic, readwrite, nullable) id<GRPCAuthorizationProtocol> authTokenProvider;

	/**
	* Initial metadata key-value pairs that should be included in the request.
	* Dictionary key is of type NSString, value should be either NSString or NSData containing binary
	* bytes data.
	*/
	@property(nonatomic, nonatomic, copy, readwrite, nullable) GRPCMetadataDictionary *initialMetadata;

	// Channel parameters; take into account of channel signature.

	/**
	* Custom string that is prefixed to a request's user-agent header field before gRPC's internal
	* user-agent string.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *userAgentPrefix;

	/**
	* Custom string that is suffixed to a request's user-agent header field after gRPC's internal
	* user-agent string.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *userAgentSuffix;

	/**
	* The size limit for the response received from server. If it is exceeded, an error with status
	* code GRPCErrorCodeResourceExhausted is returned.
	*/
	@property(nonatomic, readwrite) NSUInteger responseSizeLimit;

	/**
	* The compression algorithm to be used by the gRPC call. For more details refer to
	* https://github.com/grpc/grpc/blob/master/doc/compression.md
	*/
	@property(nonatomic, readwrite) GRPCCompressionAlgorithm compressionAlgorithm;

	/**
	* Enable/Disable gRPC call's retry feature. The default is enabled. For details of this feature
	* refer to
	* https://github.com/grpc/proposal/blob/master/A6-client-retries.md
	*/
	@property(nonatomic, readwrite) BOOL retryEnabled;

	/**
	* Maximum interval in seconds between two consecutive retries. Pass 0 to use default.
	* Internal-only property used for GTMSessionFetcher transport retry policy.
	*/
	@property(nonatomic, readwrite) NSTimeInterval maxRetryInterval;

	/**
	* Minimum interval in seconds between two consecutive retries. Pass 0 to use default.
	* Internal-only property used for GTMSessionFetcher transport retry policy.
	*/
	@property(nonatomic, readwrite) NSTimeInterval minRetryInterval;

	/**
	* Multiplier used to increase the interval between retries. Pass 0 to use default.
	* Internal-only property used for GTMSessionFetcher transport retry policy.
	*/
	@property(nonatomic, readwrite) double retryFactor;

	// HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
	// PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
	// call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
	// Negative values are invalid; setting these parameters to negative value will reset the
	// corresponding parameter to 0.
	@property(nonatomic, readwrite) NSTimeInterval keepaliveInterval;
	@property(nonatomic, readwrite) NSTimeInterval keepaliveTimeout;

	// Parameters for connection backoff. Negative value is invalid; setting the parameters to negative
	// value will reset corresponding parameter to 0.
	// For details of gRPC's backoff behavior, refer to
	// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
	@property(nonatomic, readwrite) NSTimeInterval connectMinTimeout;
	@property(nonatomic, readwrite) NSTimeInterval connectInitialBackoff;
	@property(nonatomic, readwrite) NSTimeInterval connectMaxBackoff;

	/**
	* Specify channel args to be used for this call. For a list of channel args available, see
	* grpc/grpc_types.h
	*/
	@property(nonatomic, copy, readwrite, nullable) GRPCMetadataDictionary *additionalChannelArgs;

	// Parameters for SSL authentication.

	/**
	* PEM format root certifications that is trusted. If set to nil, gRPC uses a list of default
	* root certificates.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *PEMRootCertificates;

	/**
	* PEM format private key for client authentication, if required by the server.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *PEMPrivateKey;

	/**
	* PEM format certificate chain for client authentication, if required by the server.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *PEMCertificateChain;

	/**
	* Deprecated: this option is deprecated. Please use the property \a transport
	* instead.
	*
	* Select the transport type to be used for this call.
	*/
	@property(nonatomic, readwrite) GRPCTransportType transportType;

	/**
	* The transport to be used for this call. Users may choose a native transport
	* identifier defined in \a GRPCTransport or provided by a non-native ttransport
	* implementation. If the option is left to be NULL, gRPC will use its default
	* transport.
	*
	* An interceptor must not change the value of this option.
	*/
	@property(nonatomic, readwrite) GRPCTransportID transport;

	/**
	* Override the hostname during the TLS hostname validation process.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *hostNameOverride;

	/**
	* A string that specify the domain where channel is being cached. Channels with different domains
	* will not get cached to the same channel. For example, a gRPC example app may use the channel pool
	* domain 'io.grpc.example' so that its calls do not reuse the channel created by other modules in
	* the same process.
	*/
	@property(nonatomic, copy, readwrite, nullable) NSString *channelPoolDomain;

	/**
	* Channel id allows a call to force creating a new channel (connection) rather than using a cached
	* channel. Calls using distinct channelID's will not get cached to the same channel.
	*/
	@property(nonatomic, readwrite) NSUInteger channelID;

	@end

	NS_ASSUME_NONNULL_END