as-rpc 1.0.2

Remote Procedure Caller (RPC) based-on Asynchronous IO and Socket

as_rpc

as_rpc is a python package for Remote Procedure Call (RPC) based-on Asynchronous IO and Socket.

It supports bidirectional calls, and it has very high efficiency.

Quick Start

To install as-rpc, run the command

pip install as-rpc

Let's run the program first, and then some more details on how to use as-rpc will be given.

Suppose we have two files, one for server and the other for client.

Server Example (see also test_server.py)

from as_rpc import AioRpcServer, rpc
import asyncio

server = AioRpcServer()

@rpc(server, "test")
def print_test(content):
    print("hello world!", content)
    return str(content)


@rpc(server, 0)
def test0(*args):
    return 1

@rpc(server, 1)
def test1():
    s = "this is test1."
    print(s)
    return s

@rpc(server, 2)
async def test2():
    s = "this is test2."
    print(s)
    return s

@rpc(server, 'Foo')
class Foo:
    @rpc(server, 3)
    async def test3(self):
        s = "this is test3."
        print(s)
        return s
    
    @rpc(server, 4)
    def test4(self):
        s = "this is test4."
        print(s)
        return s

@rpc(server, "call_client")
async def call_client(client_id):
    print("call client")
    msg = await server.async_call_func(client_id, "test", "msg from server")
    print(msg)

server.run()

Client Example (see also test_client.py)

import asyncio
from as_rpc import AioRpcClient, RpcServerObject, rpc
from time import time

def callback(data):
    print(data)

client = AioRpcClient()

client.init()


def main():
    print('main')
    client.call_func(1, callback)
    client.call_func("test", callback, RpcServerObject(client.id))

async def main2():
    s = await client.async_call_func(1)
    print('async', s)

async def main3():
    foo = await client.async_instantiate('Foo')
    print(foo)
    print(await client.async_call_async_method(foo, 3))
    print(await client.async_call_method(foo, 4))

@rpc(client, "test")
def test(msg):
    print(msg)
    return "return from client"

loop = asyncio.get_event_loop()
loop.call_soon(main)
loop.run_until_complete(main2())
loop.run_until_complete(main3())
loop.run_until_complete(client.async_call_async_func("call_client", client.id))

In one terminal, run the command

python test_server.py

In another terminal, run the command

python test_client.py

You will see the outputs from the server

this is test1.
hello world! None
this is test1.
this is test3.
this is test4.
call client
return from client

and the outputs from the client

main
('this is test1.', None)
('None', None)
async this is test1.
-8991251603859186137
this is test3.
this is test4.
msg from server

In the client, the program calls some functions in the server, gets the return values, and prints them.

Create and Run a Server/Client

To create a server, first import related objects

from as_rpc import AioRpcServer, rpc

and then instantiate a server by

server = AioRpcServer()

To run the server, you can either call server.init() and then start the event-loop of asyncio

server.init()
loop = asyncio.get_event_loop()
loop.run_forever()

or just call server.run() which packs the code above

server.run()

To create a client, first import related objects

from as_rpc import AioRpcClient, rpc

and then instantiate a client by

client = AioRpcClient()

To run the client, call client.init() and then start the event-loop of asyncio

client.init()
loop = asyncio.get_event_loop()
loop.run_forever()

Register Functions

You can register a function or async function by adding a decorator on a function, for example

@rpc(server, 0)
def test0(*args):
    return 0

@rpc(server, "test1")
async def test1(*args):
    return 1

In @rpc(server, name), the first parameter is the server instance, while the second parameter is the name denoting the corresponding function. Client can call this function by the name defined here. For example, in client

s = await client.async_call_async_func("test1")

There are four types of calling a function: call_func(), async_call_func(), call_async_func(), and async_call_async_func(). The meaning of them will be illustrated later (see the section "Call Functions").

In client programe, functions can also be registered in the same way.

@rpc(client, "test")
def test(msg):
    print(msg)
    return "return from client"

Call Functions

For a client, there are four types of calling a function:

• call_func(name_func, callback, *args): call a normal function directly in the remote. The first parameter is the function name in the remote (server or client); the second parameter callback is a function which would be called after the result from the remote is returned. It could be None if the returned value is not concerned. The subsequent args is a list of arguments passed to the remote.
• async_call_func(name_func, *args): call a normal function asynchronously in the remote. You can use await async_call_func(...) to get the returned value, so there is no need to claim the callback function.
• call_async_func(name_func, callback, *args): call an async function directly in the remote. The function in the remote is asynchronous, defined with keyword async. The parameters are the same as call_func().
• async_call_async_func(name_func, *args): call an async function asynchronously in the remote. The parameters are the same as call_async_func().

For a server, there are also four types of calling a function, with the same names as the above. The difference is that there is an additional parameter in the first postion of each of the four, i.e., client_id.

• call_func(client_id, name_func, callback, *args),
• async_call_func(client_id, name_func, *args),
• call_async_func(client_id, name_func, callback, *args),
• async_call_async_func(client_id, name_func, *args).

The parameter client_id determines which client to call.

An example of calling a function by server is

@rpc(server, "call_client")
async def call_client(client_id):
    print("call client")
    msg = await server.async_call_func(client_id, "test", "msg from server")
    print(msg)

All the clients' ids are avaible through server.clients.keys().

Instantiate Classes and Call Methods

For a client, you can create an instance of class in the remote by instantiate(<Remote-Class-Marker>) or async_instantiate(<Remote-Class-Marker>). The returned value is the handler of the remote instance.

To call a method of it, you can use the four

• call_method(self, name_self, name_method, callback, *args),
• async_call_method(self, name_self, name_method, *args),
• call_async_method(self, name_self, name_method, callback, *args),
• async_call_async_method(self, name_self, name_method, *args).

The difference among the four types is similar to the previous.

An example to instantiate a class and to call methods is

foo = await client.async_instantiate('Foo')
print(foo)
print(await client.async_call_async_method(foo, 3))
print(await client.async_call_method(foo, 4))

For a server, you can do similar things, except that you need to pass a parameter client_id for each calling.

That's all about the usage of as-rpc. You can raise issues in the github repo if you have questions, want to report bugs, or need more features.

Benchmark

Framework	Speed (req/s)
zero (v0.4.1)	2173
as-rpc (this repo)	10244