packetsocket

High-level socket interface for non-blocking packet communication.

Github

Description

packetsocket provides a simple, high-level class interface for non-blocking sockets communicating in packet messages. Two types of sockets are implemented: PacketSocketServer and PacketSocketClient. A server can accept incoming client connections, a client can connect to one server. Both inherit the common PacketSocket operations (open, close, update, read, write) from the base class PacketSocket. These methods are thread-safe using an internal lock.

PacketSockets work in non-blocking mode regarding the sending and receiving of socket messages. They do, however, have the option to block while waiting for the lock.

PacketSockets communicate messages as simple packets. They are composed as follows: "<HEADER_PREFIX>" where <HEADER_PREFIX> is the constant bytestring PacketSocket.HEADER_PREFIX identifying the beginning of a new message, stores the size of the body of a fixed length of PacketSocket.HEADER_BYTES bytes, and is the message itself.

Example

from queue import Queue
from threading import Thread

from packetsocket import Server, Client

ADDRESS = ("", 4200)
messages = Queue()
running = True


def runServer(messages, address, running):
    with Server(address) as server:
        while running:
            while not messages.empty():
                msg = messages.get_nowait()
                server.write(msg)

            server.update()

            for sock, msgs in server.read():
                client_name = sock.getpeername()[0]
                for msg in msgs:
                    print(f"[{client_name}] {msg.decode()}")


def runClient(messages, address, running):
    with Client(ADDRESS) as client:
        while running:
            client.update()

            for msg in client.read():
                print(f"[Server] {msg.decode()}")
                client.write(b"<Server Echo> " + msg)


def getInput(messages, running):
    while running:
        inp = input("Send message to client: \n")
        if inp.strip():
            messages.put(inp.encode())
            print("\n")


try:
    Thread(target=getInput, args=(messages, running)).start()
    Thread(target=runServer, args=(messages, ADDRESS, running)).start()
    Thread(target=runClient, args=(messages, ADDRESS, running)).start()
finally:
    running = False