rpc-framework

This is a framework for remote procedure calls in haskell.

Features

• Usage is incredibly simple!

• Calling a remote procedure is type safe.

• Modal logic inspired worlds, aka hosts:

  • Services run from the World IO monad, written Host w => WIO w
  • This allows world specific actions: if one world will be compiled to JS and one to x86, we could have the following types

 putStrLn :: IO_World w => WIO w a installTextBox :: JS_World w => WIO w () 

• Arbitrily complex remote procedures:
  • Rather than only being able to call a remote function of one argument, we can call with any number of arguments

 foo :: (Sendable a1 ,..., Sendable aN, Sendable b, Host w) => a1 -> ... -> aN -> WIO w b 

• It can send pure functions across the wire and now garbage collect them.

 instance (Serializable a) => Sendable a a instance (Sendable a' a, Sendable b b') => Sendable (a -> b) (a' -> IO b') 

• Only local code can execute

  • unlike some modal logic aproaches to mobile languages, the only code that can be executed is the code you compiled, and not code passed from world to world

• State can be serialized with references.

Usage

• To install, run cabal install

• Hosts are declared at the declaration level

 $(makeHost "WorldName" "host_location" #portNumber) 

• Installing a remote service:
  • makeServices registers a list of service names which all have the same host
  • autoService automatically figures out which services in the given file run on the specified host and registers them. A good usage pattern is to provide all modules with services with a registration hook that can be appended to the main server.

 main = runServer $(makeServices [ 'nameOfService1, ... , 'nameOfServiceN]) 

 main = runServer $(autoService 'HostName) 

 module First where services = $(autoService 'HostName) module Second where services = $(autoService 'HostName) module Main where import qualified First as F import qualified Second as S main = runServer $ F.services >> S.services 

• Calling a remote service:

 addServer :: Integer -> WIO Server (Integer -> Integer) addServer t = do Server <- world	return (t +) getRemoteAdd = $(rpcCall 'addServer) ... ghci> :t getRemoteAdd getRemoteAdd :: Host w => Integer -> WIO w (Integer -> Integer) 

Examples

• src/RPCTest.hs is an example.
  • It runs two worlds, Client and Server, both on localhost, one on port 9000 and the other on 9001.
  • To run and build it: make run
  • To build it: make test
  • To run it after building it: ./rpc-test