backend: rename network.py to network_backend.py

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/network_backend.py

@@ -0,0 +1,102 @@
+import socket
+import selectors
+from threading import Thread
+from queue import Queue
+
+from msg.container import MsgContainer
+from transceiver import Transceiver, ATransceiver
+
+from backend.a_backend import ABackend
+
+
+class NetworkBackend(ABackend):
+	def __init__(self, servers: list[dict]):
+		self.sel = None
+		self.sock_list = [{'name': s['name'], 'addr': (socket.gethostbyname(s['host']), s['port']), 'xcvr': None, 'queue': Queue()} for s in servers]
+		self.thread = Thread(target=self.event_loop)
+		self.loop_enable = True
+
+	def send(self, xcvr: ATransceiver, data: bytes):
+		sock = self.find_by_name(xcvr.name)
+		sock['queue'].put(data)
+		if sock is not None:
+			self.sel.modify(sock['sock'], selectors.EVENT_READ + selectors.EVENT_WRITE, None)
+
+	def start(self):
+		self.thread.start()
+
+	def stop(self):
+		if self.loop_enable:
+			self.loop_enable = False
+			self.thread.join()
+
+	def register_xcvr(self, xcvr: Transceiver):
+		found = False
+		for sock in self.sock_list:
+			if xcvr.name in sock['name']:
+				found = True
+				sock['xcvr'] = xcvr
+				xcvr.on_register(self)
+				break
+
+		if not found:
+			raise Exception(f"No socket found for \"{xcvr.name}\"")
+
+	def find_by_addr(self, addr):
+		for sock in self.sock_list:
+			if sock['addr'] == addr:
+				return sock
+		return None
+
+	def find_by_name(self, name: str):
+		for sock in self.sock_list:
+			if sock['name'] == name:
+				return sock
+		return None
+
+	def _prepare(self):
+		for server in self.sock_list:
+			sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+			sock.setblocking(False)
+			server['sock'] = sock
+
+	def connect(self):
+		self._prepare()
+		self.sel = selectors.DefaultSelector()
+		events = selectors.EVENT_READ
+		for sock in self.sock_list:
+			print(f"Starting connection {sock['name']} to {sock['addr']}")
+			self.sel.register(sock['sock'], events, data=None)
+			sock['sock'].connect_ex(sock['addr'])
+
+	def disconnect(self):
+		for sock in self.sock_list:
+			sock['sock'].close()
+
+	def on_send(self, name: str, data: bytes):
+		sock = self.find_by_name(name)
+		if sock is not None:
+			self.sel.modify(sock['sock'], selectors.EVENT_READ + selectors.EVENT_WRITE, data)
+
+	def event_loop(self):
+		try:
+			while self.loop_enable:
+				events = self.sel.select(timeout=100)
+				for key, mask in events:
+					descr = self.find_by_addr(key.fileobj.getpeername())
+					name = descr['name']
+					sock = self.find_by_name(name)
+					if mask & selectors.EVENT_READ:
+						data = key.fileobj.recv(64)
+						sock['xcvr'].on_recv(MsgContainer(data, sock['xcvr']))
+					if mask & selectors.EVENT_WRITE:
+						data = sock['queue'].get()
+						key.fileobj.send(data)
+						print(f"Send: {sock['name']}: {data}")
+						if sock['queue'].empty():
+							self.sel.modify(sock['sock'], selectors.EVENT_READ, None)
+
+		except KeyboardInterrupt:
+			print("Caught keyboard interrupt, exiting")
+		finally:
+			self.sel.close()