class Server:
def __init__(self, address, port, max_connections):
self.socket = Socket()
self.address = address
self.port = port
self.connections = max_connections
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.socket.__exit__(exc_type, exc_val, exc_tb)
logging.info('Server closed')
def start(self):
logging.info('Starting server')
try:
self.socket.bind((self.address, self.port))
except OSError:
logging.debug("Address already taken - {address}:{port}".format(
address=self.address, port=self.port))
exit(1)
self.socket.listen(self.connections)
logging.info('Server has been started. Waiting for connections.')
def close(self):
self.socket.close()
def accept(self):
client_sock, client_addr = self.socket.accept()
return client_sock, client_addr
class Client:
def __init__(self, address, port, buffer_size):
self.socket = Socket()
self.address = address
self.port = port
self.buffer_size = buffer_size
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.socket.__exit__()
logging.info('Client closed')
def connect(self):
logging.info('Starting client')
try:
self.socket.connect((self.address, self.port))
logging.info('Connected to {server}:{port}'.format(server=self.address, port=self.port))
except ConnectionRefusedError:
logging.warning('Failed to connect.')
logging.exception('Exception: ')
exit(1)
def send(self, payload, flags=0):
"""
Send message(payload) to socket. Appends 8 bytes with information of message length to the beginning.
"""
total_sent = 0
send_bytes = len(payload).to_bytes(8, byteorder='little') + payload
while total_sent < len(send_bytes):
try:
sent = self.socket.send(send_bytes[total_sent:])
except ConnectionResetError:
logging.warning("Connection aborted.")
logging.exception("Exception:")
exit(1)
if sent == 0:
raise RuntimeError("Connection broken")
total_sent += sent
def receive(self):
"""
Receive data by chunks of buffer size.
:return: full message without leading 8 bytes (message length)
"""
message = self.socket.recv(self.buffer_size)
if len(message) < self.buffer_size:
return message[8:] # First 8 bytes contains payload size
else:
chunks = []
payload_size, payload = int.from_bytes(message[0:8], byteorder='little'), message[8:]
chunks.append(payload)
bytes_received = len(payload)
while bytes_received < payload_size:
chunk = self.socket.recv(min(payload_size - bytes_received, self.buffer_size))
if chunk == b'':
raise RuntimeError("Socket connection broken")
chunks.append(chunk)
bytes_received += len(chunk)
return b''.join(chunks)
def ask_for_task(self):
return self.send_pickled({'Command': "NewTask"})
def receive_unpickled(self):
return pickle.loads(self.receive())
def send_pickled(self, bytes):
return self.send(pickle.dumps(bytes))