#rpc-stream
RpcStream
is a dead simple (75 loc) rpc system that works over any full-duplex text/byte/json stream.
There's also a Python port, e.g. for cross-language RPC-over-SSH.
- rpyc-stream Python
There are a bunch of people have already written node rpc systems, but most of them has done it right yet.
My beef is that all these systems is that they are tightly coupled to, or wrapped around servers. what if I want to encrypt the messages? what if I want to send the messages over stdin/out, or over ssh? of write them to a temp file? there is one abstraction that matches all of these cases; the Stream
I should just be able to do this:
REMOTE_SSH_STREAM //<-- pipe data from a remote source
.pipe(DECRYPT_STREAM) //through some ('middleware') streams (ssh already encrypts, but I'm paranoid)
.pipe(GUNZIP_STREAM)
.pipe(RPC) //<--- pipe the data through the RPC system.
.pipe(GZIP_STREAM)
.pipe(ENCYPT_STREAM)
.pipe(REMOTE_SSH_STREAM) //<-- and back to the remote
//with something very similar on the other side.
RPC framework (AHEM! RPC MODULE!), you just worry about calling the right function, I'll decide where you go...
update: [email protected] now has first class streams, and you can pipe it where you like!
var rpc = require('rpc-stream')
//create a server, that answers questions.
//pass in functions that may be called remotely.
var server = rpc({hello: function (name, cb) {
cb(null, 'hello, '+name)
}})
//create a client, that asks questions.
var client = rpc()
//pipe rpc instances together!
client.pipe(server).pipe(client)
var remote = client.wrap(['hello'])
remote.hello('JIM', function (err, mess) {
if(err) throw err
console.log(mess)
})
returns a RpcStream
that will call methods
when written to.
If opts.raw
is set to true
, JSON.stringify()
is turned off and you just
get a stream of objects, in case you want to do your own parsing/stringifying.
With opts.flattenError
you can override the default method of converting
errors to plain js objects. For example, to include non-enumerable properties
too, pass:
{flattenError: function (err) {
if(!(err instanceof Error)) return err
var err2 = { message: err.message }
var props = Object.getOwnPropertyNames(err)
for(var k in err)
err2[k] = err[k]
return err2
}}
returns a wrapped object with the remote's methods.
the client needs to already know the names of the methods.
accepts a string, and array of strings, or a object.
if it's an object, wrap
will use the keys as the method names.
//create rpc around the fs module.
var fsrpc = rpc(require('fs'))
//pipe, etc
then, in another process...
var fsrpc = rpc()
//pipe, etc
//wrap, with the right method names.
var remoteFs = fs.wrap(require('fs'))
remoteFs.mkdir('/tmp/whatever', function (err, dir) {
//yay!
})
now, the second process can call the fs
module in the first process!
wrap
does not use the methods for anything. it just wants the names.
this gets invoked by wrap. but you could call it directly.
rpc().wrap('hello').hello(name, callback)
//is the same as
rpc().rpc('hello', [name], callback)
this is why we are here. read this and this
MIT/APACHE2