FL_Part2_5.py

import socket
import pickle
import time

def recv(connection, buffer_size, recv_timeout):
    recv_start_time = time.time() # Time at which last chunk is received from the client.
    received_data = b""
    while True:
        try:
            data = connection.recv(buffer_size)
            received_data += data

            if data == b'': # Nothing received from the client.
                received_data = b""
                # If still nothing received for a number of seconds specified by the recv_timeout attribute, return with status 0 to close the connection.
                if (time.time() - recv_start_time) > recv_timeout:
                    return None, 0 # 0 means the connection is no longer active and it should be closed.
            elif str(data)[-2] == '.':
                print("All data ({data_len} bytes) Received.".format(data_len=len(received_data)))

                if len(received_data) > 0:
                    try:
                        # Decoding the data (bytes).
                        received_data = pickle.loads(received_data)
                        # Returning the decoded data.
                        return received_data, 1

                    except BaseException as e:
                        print("Error Decoding the Client's Data: {msg}.\n".format(msg=e))
                        return None, 0
            else:
                # In case data are received from the client, update the recv_start_time to the current time to reset the timeout counter.
                recv_start_time = time.time()

        except BaseException as e:
            print("Error Receiving Data from the Client: {msg}.\n".format(msg=e))
            return None, 0

soc = socket.socket()
print("Socket is created.")

soc.bind(("localhost", 10000))
print("Socket is bound to an address & port number.")

soc.listen(1)
print("Listening for incoming connection ...")

connected = False
accept_timeout = 10
soc.settimeout(accept_timeout)
try:
    connection, address = soc.accept()
    print("Connected to a client: {client_info}.".format(client_info=address))
    connected = True
except socket.timeout:
    print("A socket.timeout exception occurred because the server did not receive any connection for {accept_timeout} seconds.".format(accept_timeout=accept_timeout))

received_data = b''
if connected:
    while True:
        recv_start_time = time.time()
        time_struct = time.gmtime()
        date_time = "Waiting to Receive Data Starting from {day}/{month}/{year} {hour}:{minute}:{second} GMT".format(year=time_struct.tm_year, month=time_struct.tm_mon, day=time_struct.tm_mday, hour=time_struct.tm_hour, minute=time_struct.tm_min, second=time_struct.tm_sec)
        print(date_time)
        recv_timeout = 5
        received_data, status = recv(connection, 8, recv_timeout)
        print("Received data from the client: {received_data}".format(received_data=received_data))
        if status == 0:
            connection.close()
            print("Connection Closed either due to inactivity for {recv_timeout} seconds or due to an error.".format(recv_timeout=recv_timeout), end="\n\n")
            break

        msg = "Reply from the server."
        msg = pickle.dumps(msg)
        connection.sendall(msg)
        print("Server sent a message to the client.")

soc.close()
print("Socket is closed.")