def recv(self):
"""
Recieves data from file socket
NOTE : in this configuration the recv function is BLOCKING (as opposed to non-blocking)
which seems normal since we do not want to read nor send empty strings to the other socket
:return: returns string data or False if socket is closed or timed out
"""
''' timeout counter '''
while self.counter < self.timeout:
''' check if file exists and writing has finished, if yes we do our job'''
if h.exists(self.outputStreamFilename) and h.exists(
self.outputStreamFilenameSemaphore):
break
''' if sock is closed or timeout reached we return False'''
if self.is_out_closed() or self.counter == self.timeout - 1:
return False
''' if nothing else, we sleep and increment timeout counter'''
time.sleep(1)
self.counter += 1
result = h.read(self.outputStreamFilename)
h.delete(self.outputStreamFilename)
h.delete(self.outputStreamFilenameSemaphore)
self.counter = 0
return result
def connect(self, hostname_port_tuple, timestamp):
''' hostname_port_tuple - ("hostname",portnumber) '''
''' timestamp - identifier of the socket (None if it is a new connection, str of digits if it is an established connection'''
self.hostname = hostname_port_tuple[0]
self.port = int(hostname_port_tuple[1])
''' if new connection'''
self.timestamp = str(int(timestamp))
if not self.reverse:
self.inputStreamFilename = self.SOCKET_DIR + self.hostname + self.DELIMITER + str(
self.port) + '.' + self.timestamp + '.in'
self.outputStreamFilename = self.SOCKET_DIR + self.hostname + self.DELIMITER + str(
self.port) + '.' + self.timestamp + '.out'
else:
self.inputStreamFilename = self.SOCKET_DIR + self.hostname + self.DELIMITER + str(
self.port) + '.' + self.timestamp + '.out'
self.outputStreamFilename = self.SOCKET_DIR + self.hostname + self.DELIMITER + str(
self.port) + '.' + self.timestamp + '.in'
self.inputStreamFilenameSemaphore = self.inputStreamFilename + '.written'
self.outputStreamFilenameSemaphore = self.outputStreamFilename + '.written'
''' create directory for fileSockets'''
if not h.exists(self.SOCKET_DIR):
h.make_dir(self.SOCKET_DIR)
return self
def is_in_closed(self):
"""
Checks whether the input stream has been closed
:return: returns True if it is and false if it isn't
"""
return h.exists(self.inputStreamFilename + ".closed")
def touch(self, filename):
"""
creates empty file if it does not exist, does nothing otherwise
:param filename: absolute path to filename to create
:return:
"""
if not h.exists(filename):
h.write(filename, '')
def send(self, data):
"""
Sends data to file socket
:param data: data string to be sent over the file socket
:return: return None if socket is closed and True if data was written to socket
"""
''' timeout counter '''
#counter = 0
while self.counter < self.timeout:
''' 1. check if socket is closed '''
if self.is_in_closed() or self.counter == self.timeout - 1:
return False
''' 2. check if the file is not existent, if it isn't we create and write to it'''
if not h.exists(self.inputStreamFilename) and not h.exists(
self.inputStreamFilenameSemaphore):
break
time.sleep(1)
self.counter += 1
h.write(self.inputStreamFilename, data)
h.write(self.inputStreamFilenameSemaphore, '')
self.counter = 0
return True
def is_out_closed(self):
"""
Checks whether the output stream has been closed
:return:
"""
return h.exists(self.outputStreamFilename + ".closed")