EMRPC is a EventMachine-based remote procedure call library. It looks like DRb, but is much more efficient and provides asynchronous erlang-like interface along with blocking synchronous interface.

Author: Oleg Andreev [email protected]

FEATURES

0. Object-oriented evented API based on lightweight processes called Pids.
1. Automatically reconnecting clients (blocking and evented).
2. Support for both TCP and Unix sockets. (Use "emrpc://host:port" or "unix:///path/to/my.sock")
3. Modularity and good specs coverage: EMRPC is easy to learn, extend and optimize.

VERSION AND STATUS

This is v0.3 alpha. It is being used in several projects of my own, but is not tested on many interesting cases. It has also several issues with performance and specs stability (see TODO file).

THANKS TO

• linkfeed.ru for the real-world EMRPC-based application.
• pierlis.com for the table/chair/wifi in Paris.

EXAMPLES

You may try out examples using bin/emrpc IRB session. Just open the console and paste the code.

HELLO WORLD (BLOCKING API)

class HelloWorld def action "Hello!" end end

server = EMRPC::Server.new(:address => 'emrpc://localhost:4000/', :backend => HelloWorld.new) EM::safe_run(:background) { }

server.start

client = EMRPC::Client.new('emrpc://localhost:4000/') client.action == "Hello!" #=> true

HELLO WORLD (EVENTED API)

class HelloWorld include Pid def action(sender) puts "HelloWorld replies to the sender #{sender}..." sender.reply(self, "Hello!") end end

class User include Pid def connected(pid) puts "Pid #{pid} connected with the user." pid.action(self) end def reply(pid, msg) puts "Pid #{pid} replied: #{msg}" end end

EM::run do hw = HelloWorld.new hw.bind('emrpc://localhost:4000/') # bind a pid to the address

oleg = User.new
oleg.connect('emrpc://localhost:4000/') # connect to that address

end

Output:

Pid #EMRPC::RemotePid:0x143b740 connected with the user. HelloWorld replies to the sender #User:0x143b4d4... Pid #HelloWorld:0x143d540 replied: Hello!

HELLO WORLD (EVENTED WRAPPER, MIXED API)

in first process:

class HelloWorld def action "Hello!" end end

server = EMRPC::Server.new(:address => 'emrpc://localhost:4000/', :backend => HelloWorld.new)

EM::run do server.start end

in the other process (actually, this works in the same process with the server too):

class User include Pid def connected(pid) puts "Pid #{pid} connected to the user." pid.send(self, :action) end def on_return(pid, msg) puts "Pid #{pid} replied: #{msg}" end end

EM::run do oleg = User.new oleg.connect('emrpc://localhost:4000/') # connect to that address end

Output:

Pid #EMRPC::RemotePid:0x143b740 connected to the user. Pid #HelloWorld:0x143d540 replied: Hello!