/// <summary>
/// Intercepts an asynchronous invocation of a simple remote call.
/// </summary>
/// <param name="request">The request message of the invocation.</param>
/// <param name="context">The <see cref="ClientInterceptorContext{TRequest, TResponse}" />
/// associated with the current invocation.</param>
/// <param name="continuation">The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// request value and context arguments, or substitute them as it sees fit.</param>
/// <returns>
/// An instance of <see cref="AsyncUnaryCall{TResponse}" />
/// representing an asynchronous unary invocation.
/// The interceptor can simply return the return value of the
/// continuation delegate passed to it intact, or construct its
/// own substitute as it sees fit.
/// </returns>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request, ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
AsyncUnaryCall <TResponse> call = continuation(request, context);
Task t = call.ResponseAsync.ContinueWith(
delegate(Task <TResponse> oldTask)
{
// Generating log entry is expensive, so let's do that only if the log source
// has been configured to do so.
if (TraceUtilities.ShouldGenerateRequestLogs())
{
LogEntry logEntry = new LogEntry()
{
Host = Config.ServerUrl,
Method = context.Method.FullName,
RequestHeaders = context.Options.Headers,
Request = request,
ResponseHeaders = GetResponseHeader(call),
Response = (oldTask.IsFaulted) ? default(TResponse) : oldTask.Result,
Exception = GetGoogleAdsException(oldTask.Exception),
IsFailure = oldTask.IsFaulted,
CustomerId = GetCustomerId(request),
PartialFailures = (oldTask.IsFaulted)? "" :
GetPartialFailures(oldTask.Result)
};
OnLogEventAvailable?.Invoke(this, logEntry);
}
});
t.Wait();
return(call);
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var now = Util.EpochTimeMillis();
var keyLevel = authentication.KeyLevel;
var signer = crypto.CreateSigner(keyLevel);
var payload = new GrpcAuthPayload
{
Request = ByteString.CopyFrom(((IMessage)request).ToByteArray()),
CreatedAtMs = now
};
var signature = signer.Sign(payload);
var metadata = context.Options.Headers ?? new Metadata();
metadata.Add("token-realm", "Token");
metadata.Add("token-scheme", "Token-Ed25519-SHA512");
metadata.Add("token-key-id", signer.GetKeyId());
metadata.Add("token-signature", signature);
metadata.Add("token-created-at-ms", now.ToString());
metadata.Add("token-member-id", memberId);
metadata.Add("token-security-metadata", encodeSecurityMetadata(authentication));
if (authentication.OnBehalfOf != null)
{
metadata.Add("token-on-behalf-of", authentication.OnBehalfOf);
metadata.Add("customer-initiated", authentication.CustomerInitiated.ToString());
}
return(continuation(request,
new ClientInterceptorContext <TRequest, TResponse>(context.Method, context.Host,
context.Options.WithHeaders(metadata))));
}
/// <summary>
/// Intercepts an asynchronous invocation of a simple remote call.
/// </summary>
/// <param name="request">The request message of the invocation.</param>
/// <param name="context">The <see cref="ClientInterceptorContext{TRequest, TResponse}" />
/// associated with the current invocation.</param>
/// <param name="continuation">The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// request value and context arguments, or substitute them as it sees fit.</param>
/// <returns>
/// An instance of <see cref="AsyncUnaryCall{TResponse}" />
/// representing an asynchronous unary invocation.
/// The interceptor can simply return the return value of the
/// continuation delegate passed to it intact, or construct its
/// own substitute as it sees fit.
/// </returns>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request, ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
AsyncUnaryCall <TResponse> call = continuation(request, context);
call.ResponseAsync.ContinueWith(
delegate(Task <TResponse> oldTask)
{
LogEntry logEntry = new LogEntry()
{
Host = Config.ServerUrl,
Method = context.Method.FullName,
RequestHeaders = context.Options.Headers,
Request = request,
ResponseHeaders = GetResponseHeader(call),
Response = (oldTask.IsFaulted) ? default(TResponse) : oldTask.Result,
Exception = GetGoogleAdsException(oldTask.Exception),
IsFailure = oldTask.IsFaulted,
CustomerId = GetCustomerId(request)
};
OnLogEventAvailable?.Invoke(this, logEntry);
});
return(call);
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
_logger.Info($"Begin '{context.Method.Name}' request with '{request.ToString()}'");
var responseContinuation = continuation(request, context);
var responseAsync = responseContinuation.ResponseAsync.ContinueWith(responseTask =>
{
try
{
var response = responseTask.Result;
_logger.Info($"Request to '{context.Method.Name}' with '{request.ToString()}' succeeded!");
return(response);
}
catch (AggregateException ex)
{
_logger.Error($"Request to '{context.Method.Name}' with '{request.ToString()}' failed!", ex.InnerException);
throw ex.InnerException;
}
});
var responseHeaderAsync = responseContinuation.ResponseHeadersAsync.ContinueWith(headerTask =>
{
var responseHeader = headerTask.Result;
_logger.Info($"Request to '{request.ToString()}' response headers: '{string.Join(",", (responseHeader as IList<Metadata.Entry>).Select(entry => entry.ToString()))}'");
return(responseHeader);
});
return(new AsyncUnaryCall <TResponse>(responseAsync, responseHeaderAsync, responseContinuation.GetStatus, responseContinuation.GetTrailers, responseContinuation.Dispose));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
return(continuation(request, GetNewContext(context)));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation
)
{
var builder = new StringBuilder();
// Call gRPC begin
builder.AppendLine($"Call gRPC {context.Host}/{context.Method} begin.");
// Logging Request
builder.AppendLine(LogRequest(request));
// Logging Response
var reply = continuation(request, context);
var response = reply.ResponseAsync.Result;
var exception = reply.ResponseAsync.Exception;
builder.AppendLine(LogResponse(response, exception));
// Call gRPC finish
builder.AppendLine($"Call gRPC {context.Host}/{context.Method} finish.");
Console.WriteLine(builder.ToString());
return(reply);
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
this._logger.LogInformation("AsyncUnaryCall called");
return(base.AsyncUnaryCall(request, context, continuation));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest,
TResponse>(TRequest request, ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
long startTicks = timeSource.GetTimestampTicks();
return(HandleResponseAsync(continuation(request, context),
(response) => TracingResponseAsync(request, context, response, startTicks)));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var call = continuation(request, context);
return(new AsyncUnaryCall <TResponse>(HandleResponse(call.ResponseAsync), call.ResponseHeadersAsync, call.GetStatus, call.GetTrailers, call.Dispose));
}
public override AsyncUnaryCall<TResponse> AsyncUnaryCall<TRequest, TResponse
(
TRequest request,
ClientInterceptorContext<TRequest, TResponse> context,
AsyncUnaryCallContinuation<TRequest, TResponse> continuation
)
{
return base.AsyncUnaryCall(request, context, continuation);
}
/*
* BlockingUnaryCall 拦截阻塞调用
* AsyncUnaryCall 拦截异步调用
* AsyncServerStreamingCall 拦截异步服务端流调用
* AsyncClientStreamingCall 拦截异步客户端流调用
* AsyncDuplexStreamingCall 拦截异步双向流调用
* UnaryServerHandler 用于拦截和传入普通调用服务器端处理程序
* ClientStreamingServerHandler 用于拦截客户端流调用的服务器端处理程序
* ServerStreamingServerHandler 用于拦截服务端流调用的服务器端处理程序
* DuplexStreamingServerHandler 用于拦截双向流调用的服务器端处理程序
*/
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
LogCall(context.Method);
return(continuation(request, context));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
Console.WriteLine("Logs");
return(continuation(request, context));
}
/// <summary>
/// Intercept and add headers to a AsyncUnaryCall.
/// </summary>
/// <param name="request">The request to intercept.</param>
/// <param name="context">The client interceptor context to add headers to.</param>
/// <param name="continuation">The continuation of the request after all headers have been added.</param>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
AddCallerMetadata(ref context);
return(continuation(request, context));
}
private AsyncUnaryCallContinuation <TRequest, TResponse> getAsyncUnaryCallChain <TRequest, TResponse>(Interceptor interceptor, AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
where TRequest : class
where TResponse : class
{
AsyncUnaryCallContinuation <TRequest, TResponse> fun = (fRequest, fContext) =>
{
return(interceptor.AsyncUnaryCall(fRequest, fContext, continuation));
};
return(fun);
}
/// <summary>
/// AsyncUnaryCall
/// </summary>
/// <typeparam name="TRequest"></typeparam>
/// <typeparam name="TResponse"></typeparam>
/// <param name="request"></param>
/// <param name="context"></param>
/// <param name="continuation"></param>
/// <returns></returns>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request
, ClientInterceptorContext <TRequest, TResponse> context
, AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
return(Call(context
, () =>
{
return continuation(request, context);
}
, request) as AsyncUnaryCall <TResponse>);
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var now = Util.EpochTimeMillis();
var keyLevel = authentication.KeyLevel;
var signer = crypto.CreateSigner(keyLevel);
var payload = new GrpcAuthPayload
{
Request = ByteString.CopyFrom(((IMessage)request).ToByteArray()),
CreatedAtMs = now
};
var signature = signer.Sign(payload);
var metadata = context.Options.Headers ?? new Metadata();
metadata.Add(TOKEN_REALM, "Token");
metadata.Add(TOKEN_SCHEME, "Token-Ed25519-SHA512");
metadata.Add(TOKEN_KEY_ID, signer.GetKeyId());
metadata.Add(TOKEN_SIGNATURE, signature);
metadata.Add(TOKEN_CREATED_AT_MS, now.ToString());
metadata.Add(TOKEN_MEMBER_ID, memberId);
var customer = authentication.CustomerTrackingMetadata;
if (!string.IsNullOrEmpty(customer.IpAddress))
{
metadata.Add(CUSTOMER_IP_ADDRESS_KEY,
customer.IpAddress);
}
if (!string.IsNullOrEmpty(customer.GeoLocation))
{
metadata.Add(CUSTOMER_GEO_LOCATION_KEY,
customer.GeoLocation);
}
if (!string.IsNullOrEmpty(customer.DeviceId))
{
metadata.Add(CUSTOMER_DEVICE_ID_KEY,
customer.DeviceId);
}
if (authentication.OnBehalfOf != null)
{
metadata.Add(TOKEN_ON_BEHALF_OF, authentication.OnBehalfOf);
metadata.Add(CUSTOMER_INITIATED, authentication.CustomerInitiated.ToString());
}
return(continuation(request,
new ClientInterceptorContext <TRequest, TResponse>(context.Method, context.Host,
context.Options.WithHeaders(metadata))));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var deadline = DateTime.UtcNow.AddMilliseconds(timeoutMs);
return(continuation(
request,
new ClientInterceptorContext <TRequest, TResponse>(
context.Method,
context.Host,
context.Options.WithDeadline(deadline))));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
try
{
return(continuation(request, context));
}
catch (Exception exception)
{
_logger.LogError(exception, "Context: {@Context} failed.", context);
throw new RpcException(new Status(StatusCode.Unknown, "Request failed.", exception));
}
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var metadata = context.Options.Headers ?? new Metadata();
metadata.Add("X-Correlation-ID", $"{Guid.NewGuid()}");
var newContext = new ClientInterceptorContext <TRequest, TResponse>(
context.Method,
context.Host,
context.Options.WithHeaders(metadata));
return(continuation(request, newContext));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
AsyncUnaryCall <TResponse> call = null;
var headers = new TaskCompletionSource <Metadata>();
var task = RetryWrapper(() => call = continuation(request, context), headers);
return(new AsyncUnaryCall <TResponse>(
task, headers.Task,
() => call.GetStatus(),
() => call.GetTrailers(),
() => call.Dispose()));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var response = continuation(request, context);
return(new AsyncUnaryCall <TResponse>(response.ResponseAsync.ContinueWith(t => {
if (t.Exception?.InnerException is RpcException ex)
{
throw ConvertRpcException(ex);
}
return t.Result;
}), response.ResponseHeadersAsync, response.GetStatus, response.GetTrailers, response.Dispose));
}
/// <summary>
/// Intercepts an asynchronous invocation of a simple remote call.
/// </summary>
/// <param name="request">The request message of the invocation.</param>
/// <param name="context">The <see cref="ClientInterceptorContext{TRequest, TResponse}" />
/// associated with the current invocation.</param>
/// <param name="continuationCallback">The callback that continues the invocation process.
/// This can be invoked zero or more times by the interceptor.
/// The interceptor can invoke the continuation passing the given
/// request value and context arguments, or substitute them as it sees fit.</param>
/// <returns>
/// An instance of <see cref="AsyncUnaryCall{TResponse}" />
/// representing an asynchronous unary invocation.
/// The interceptor can simply return the return value of the
/// <paramref name="continuationCallback"/> delegate passed to it intact, or construct its
/// own substitute.
/// </returns>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request, ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuationCallback)
{
AsyncUnaryCall <TResponse> call = continuationCallback(request, context);
Task t = call.ResponseAsync.ContinueWith(
delegate(Task <TResponse> oldTask)
{
loggingHandler.HandleAsyncUnaryLogging(request, context, oldTask, call);
});
t.Wait();
return(UnaryRpcInterceptor.Intercept(call));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var callContext = new ClientCallInterceptorContext(context.Options, context.Host, context.Method);
var call = base.AsyncUnaryCall(request, context, continuation);
return(new AsyncUnaryCall <TResponse>(
WaitAsyncUnaryCall(callContext, call.ResponseAsync),
call.ResponseHeadersAsync,
call.GetStatus,
call.GetTrailers,
call.Dispose));
}
/// <inheritdoc/>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
ClientRpcScope <TRequest, TResponse> rpcScope = null;
try
{
rpcScope = new ClientRpcScope <TRequest, TResponse>(context, this.options);
rpcScope.RecordRequest(request);
var responseContinuation = continuation(request, rpcScope.Context);
var responseAsync = responseContinuation.ResponseAsync.ContinueWith(
responseTask =>
{
try
{
var response = responseTask.Result;
rpcScope.RecordResponse(response);
rpcScope.Complete();
return(response);
}
catch (AggregateException ex)
{
rpcScope.CompleteWithException(ex.InnerException);
throw ex.InnerException;
}
});
return(new AsyncUnaryCall <TResponse>(
responseAsync,
responseContinuation.ResponseHeadersAsync,
responseContinuation.GetStatus,
responseContinuation.GetTrailers,
responseContinuation.WithBestEffortDispose(rpcScope)));
}
catch (Exception e)
{
rpcScope?.CompleteWithException(e);
throw;
}
finally
{
rpcScope?.RestoreParentActivity();
}
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var token = _httpContextAcessor.HttpContext.Request.Headers["Authorization"];
var headers = new Metadata
{
{ "Authorization", token }
};
var options = context.Options.WithHeaders(headers);
context = new ClientInterceptorContext <TRequest, TResponse>(context.Method, context.Host, options);
return(base.AsyncUnaryCall(request, context, continuation));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var tokenResponse = _client.GetAccessTokenAsync().Result;
var headers = context.Options.Headers;
if (headers == null)
{
headers = new Metadata();
var options = context.Options.WithHeaders(headers);
context = new ClientInterceptorContext <TRequest, TResponse>(context.Method, context.Host, options);
}
headers.Add("Authorization", $"{tokenResponse.TokenType} {tokenResponse.AccessToken}");
return(continuation(request, context));
}
/// <summary>
/// This is how I will call my grpc service from the server.
/// This method override to provide the token via header to call the GRPC server.
/// </summary>
/// <param name="request"></param>
/// <param name="context"></param>
/// <param name="continuation"></param>
/// <typeparam name="TRequest"></typeparam>
/// <typeparam name="TResponse"></typeparam>
/// <returns></returns>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var token = _httpContextAccessor.HttpContext.Request.Headers["Authorization"];
var headers = new Metadata
{
{ "Authorization", token }
};
//It will take my request context that I intercepted and I will add headers
var options = context.Options.WithHeaders(headers);
//It will create a new context to understand that there is a new header
context = new ClientInterceptorContext <TRequest, TResponse>(context.Method, context.Host, options);
return(base.AsyncUnaryCall(request, context, continuation));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request,
ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
var token = _httpContextAccesor.HttpContext.User.Claims
.FirstOrDefault(c => c.Type == "JWT")?.Value;
var headers = new Metadata
{
{ "Authorization", $"Bearer {token}" }
};
var options = context.Options.WithHeaders(headers);
context = new ClientInterceptorContext <TRequest, TResponse>(context.Method, context.Host, options);
var call = continuation(request, context);
return(new AsyncUnaryCall <TResponse>(HandleResponse(call.ResponseAsync), call.ResponseHeadersAsync, call.GetStatus, call.GetTrailers, call.Dispose));
}
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(
TRequest request, ClientInterceptorContext <TRequest, TResponse> context,
AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
SecretKeyEncryption?ske = null;
byte[]? key = null;
if (request is ISessionSecuredMessage ssmRequ)
{
if (ske == null || key == null)
{
(ske, key) = ResolveSessionKey(context.Options.Headers);
}
try
{
ssmRequ.Encrypt(ske, key);
}
catch (Exception ex)
{
throw new RpcException(new Status(StatusCode.Internal,
"failed to encrypt session-secured input message: " + ex.Message));
}
}
var call = continuation(request, context);
var response = HandleResponse <TResponse>(call.ResponseAsync, ske, key, context.Options.Headers);
return(new AsyncUnaryCall <TResponse>(
response,
call.ResponseHeadersAsync,
call.GetStatus,
call.GetTrailers,
call.Dispose));
}
/// <summary>
///
/// </summary>
/// <typeparam name="TRequest"></typeparam>
/// <typeparam name="TResponse"></typeparam>
/// <param name="request"></param>
/// <param name="context"></param>
/// <param name="continuation"></param>
/// <returns></returns>
/// <exception cref="AppException"></exception>
/// <exception cref="UnauthorizedAccessException"></exception>
public override AsyncUnaryCall <TResponse> AsyncUnaryCall <TRequest, TResponse>(TRequest request, ClientInterceptorContext <TRequest, TResponse> context, AsyncUnaryCallContinuation <TRequest, TResponse> continuation)
{
try
{
return(continuation(request, context));
}
catch (RpcException rpc)
{
HandleException(rpc);
}
// never reached
return(null);
}
