Ok. Here is my situation:
I am developing an embedded device, which provide a service. It will provide some web based services to a client (a smart phone).
Currently we are planning to implement a REST server in the device so that web applications can easily access and use the services provided by the device.
In the future, we plan to add a display and a better processor to our embedded device so that we can run the web applications on the device itself.
We want to maintain application compatibility – i.e all the current web applications should work on the device without any modifications.
Is there a better way to implement this than using REST and HTTP? I am worried about performance running both the server and the client on the device.
If you take care to separate the REST Api code from the actual service code, your newer device can interface (direct call) directly with the service instead of wrapping everything into HTTP and REST.
This being said, you can always try an implementation using you REST api and validate if performance is adequate. If it is, you do not even need to add the indirection.