public TMessage CallMethod <TMessage, TBuilder>(string method, IMessageLite request,
IBuilderLite <TMessage, TBuilder> response)
where TMessage : IMessageLite <TMessage, TBuilder>
where TBuilder : IBuilderLite <TMessage, TBuilder>
{
//obviously you could do anything here... create a logging adapter, forward messages to another server, whatever.
using (RpcCallContext.Current.Impersonate())
{
//do some test to see if the use is allowed...
WindowsIdentity userId = (WindowsIdentity)RpcCallContext.Current.ClientUser;
Assert.IsFalse(userId.IsAnonymous);
Assert.IsFalse(userId.IsGuest);
//then, call the final target:
return(_next.CallMethod(method, request, response));
}
}
TMessage IRpcDispatch.CallMethod <TMessage, TBuilder>(string method, IMessageLite request,
IBuilderLite <TMessage, TBuilder> response)
{
int size = request.SerializedSize;
if (size < multiPartThreshold)
{
return(next.CallMethod(method, request, response));
}
else
{
ByteString transaction = ByteString.CopyFrom(Guid.NewGuid().ToByteArray());
byte[] requestBytes = request.ToByteArray();
RpcMultiPartRequest.Types.RpcMessageStatus status = RpcMultiPartRequest.Types.RpcMessageStatus.CONTINUE;
try
{
int total = requestBytes.Length;
int amt = multiPartThreshold - 1024; //reserved for header
RpcMultiPartResponse mpr = RpcMultiPartResponse.DefaultInstance;
for (int pos = 0; pos < total; pos += amt)
{
amt = Math.Min(amt, total - pos);
status = (pos + amt) < total ? status : RpcMultiPartRequest.Types.RpcMessageStatus.COMPLETE;
mpr = next.CallMethod(".multi",
RpcMultiPartRequest.CreateBuilder()
.SetTransactionId(transaction)
.SetMethodName(method)
.SetMessageStatus(status)
.SetCurrentPosition(pos)
.SetTotalBytes(total)
.SetBytesSent(amt)
.SetPayloadBytes(ByteString.CopyFrom(requestBytes, pos, amt))
.Build(),
RpcMultiPartResponse.CreateBuilder()
);
if (!mpr.Continue)
{
throw new InvalidDataException("The operation was canceled by the server.");
}
}
if (!mpr.HasResponseBytes)
{
throw new InvalidDataException("The server did not provide a response.");
}
return(response.MergeFrom(mpr.ResponseBytes.ToByteArray(), extensions).Build());
}
catch
{
if (status == RpcMultiPartRequest.Types.RpcMessageStatus.CONTINUE)
{
try
{
next.CallMethod(".multi",
RpcMultiPartRequest.CreateBuilder()
.SetTransactionId(transaction)
.SetMessageStatus(RpcMultiPartRequest.Types.RpcMessageStatus.CANCEL)
.Build(),
RpcVoid.CreateBuilder()
);
}
catch (Exception e)
{
Trace.TraceWarning("Unable to cancel multi-part message: {0}, error = {1}", transaction, e);
}
}
throw;
}
}
}