Prevent code duplication for almost identical interfaces

Prevent code duplication for almost identical interfaces

In my current project, I have a rather funky device, that can perform all
kinds of streaming options, for instance, video streaming, audio
streaming, and certain kinds of data streaming.
Each device only supports a limited number of each of these streams. For
the sake of argument, assume it can support 2 video streams and 1 audio
stream.
I designed it somewhat like below. (Most application logic is left out.)
public class FunkyDevice
{
int openVideoStreams;
int openAudioStreams;
public VideoStream openVideoStream(int id)
{
if (openVideoStreams < 2)
{
openVideoStreams++;
return new VideoStream(...);
}
}
public AudioStream openAudioStream(int id)
{
if (openAudioStreams < 1)
{
openAudioStreams++;
return new AudioStream(...);
}
}
}
However, now I need to support more than 1 device. I group these in a user
session. Every user session also limits the number of each stream, but of
course these numbers are not the same as the device limitations (otherwise
the problem would be too easy). For instance, I can have 3 video streams
(to either 1, 2, or 3 different devices) and still 1 audio stream.
My best attempt to deal with this is as follows:
public class UserSession
{
int openVideoStreams;
int openAudioStreams;
public VideoStream openVideoStream(int deviceId, int id)
{
if (openVideoStreams < 3)
{
openVideoStreams++;
return getDevice(deviceId).openVideoStream(id);
}
}
public AudioStream openAudioStream(int deviceId, int id)
{
if (openAudioStreams < 1)
{
openAudioStreams++;
return getDevice(deviceId).openAudioStream(id);
}
}
}
As you can see, the public interfaces of FunkyDevice and UserSession are
almost identical, except that every method in UserSession has an
additional parameter deviceId. In my real application, I have much more
than 2 different types of streams (and also want to perform other
operations, such as closing the streams), so the interfaces become quite
large.
Is there a nicer pattern to facilitate this without introducing this code
duplication?