From: Christian Heller Date: Fri, 15 Feb 2019 02:32:51 +0000 (+0100) Subject: Refactor socket code. X-Git-Url: https://plomlompom.com/repos/%7B%7Bprefix%7D%7D/static/%7B%7Byoutube_prefix%7D%7D%7B%7Bvideo_id%7D%7D?a=commitdiff_plain;h=a455c9f392345a42c0dec745db3b65080172db77;p=plomrogue2-experiments Refactor socket code. --- diff --git a/client-curses.py b/client-curses.py index a8add97..f65d3a0 100755 --- a/client-curses.py +++ b/client-curses.py @@ -1,6 +1,6 @@ #!/usr/bin/env python3 import curses -import plom_socket_io +import plom_socket import socket import threading from parser import ArgError, Parser @@ -186,8 +186,8 @@ ASCII_printable = ' !"#$%&\'\(\)*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWX' 'YZ[\\]^_\`abcdefghijklmnopqrstuvwxyz{|}~' -def recv_loop(socket, game): - for msg in plom_socket_io.recv(s): +def recv_loop(plom_socket, game): + for msg in plom_socket.recv(): game.handle_input(msg) @@ -353,8 +353,8 @@ class TurnWidget(Widget): class TUI: - def __init__(self, socket, game): - self.socket = socket + def __init__(self, plom_socket, game): + self.socket = plom_socket self.game = game self.parser = Parser(self.game) self.to_update = {'edit': False} @@ -400,26 +400,26 @@ class TUI: elif map_mode: if type(self.game.world.map_) == MapSquare: if key == 'a': - plom_socket_io.send(self.socket, 'TASK:MOVE LEFT') + self.socket.send('TASK:MOVE LEFT') elif key == 'd': - plom_socket_io.send(self.socket, 'TASK:MOVE RIGHT') + self.socket.send('TASK:MOVE RIGHT') elif key == 'w': - plom_socket_io.send(self.socket, 'TASK:MOVE UP') + self.socket.send('TASK:MOVE UP') elif key == 's': - plom_socket_io.send(self.socket, 'TASK:MOVE DOWN') + self.socket.send('TASK:MOVE DOWN') elif type(self.game.world.map_) == MapHex: if key == 'w': - plom_socket_io.send(self.socket, 'TASK:MOVE UPLEFT') + self.socket.send('TASK:MOVE UPLEFT') elif key == 'e': - plom_socket_io.send(self.socket, 'TASK:MOVE UPRIGHT') + self.socket.send('TASK:MOVE UPRIGHT') if key == 's': - plom_socket_io.send(self.socket, 'TASK:MOVE LEFT') + self.socket.send('TASK:MOVE LEFT') elif key == 'd': - plom_socket_io.send(self.socket, 'TASK:MOVE RIGHT') + self.socket.send('TASK:MOVE RIGHT') if key == 'x': - plom_socket_io.send(self.socket, 'TASK:MOVE DOWNLEFT') + self.socket.send('TASK:MOVE DOWNLEFT') elif key == 'c': - plom_socket_io.send(self.socket, 'TASK:MOVE DOWNRIGHT') + self.socket.send('TASK:MOVE DOWNRIGHT') else: if len(key) == 1 and key in ASCII_printable and \ len(self.to_send) < len(self.edit): @@ -429,7 +429,7 @@ class TUI: self.to_send[:] = self.to_send[:-1] self.to_update['edit'] = True elif key == '\n': # Return key - plom_socket_io.send(self.socket, ''.join(self.to_send)) + self.socket.send(''.join(self.to_send)) self.to_send[:] = [] self.to_update['edit'] = True except curses.error: @@ -439,7 +439,8 @@ class TUI: s = socket.create_connection(('127.0.0.1', 5000)) +plom_socket = plom_socket.PlomSocket(s) game = Game() -t = threading.Thread(target=recv_loop, args=(s, game)) +t = threading.Thread(target=recv_loop, args=(plom_socket, game)) t.start() -TUI(s, game) +TUI(plom_socket, game) diff --git a/plom_socket.py b/plom_socket.py new file mode 100644 index 0000000..e43560d --- /dev/null +++ b/plom_socket.py @@ -0,0 +1,95 @@ +class BrokenSocketConnection(Exception): + pass + + + +class PlomSocket: + + def __init__(self, socket): + self.socket = socket + + def send(self, message, silent_connection_break=False): + """Send via self.socket, encoded/delimited as way recv() expects. + + In detail, all \ and $ in message are escaped with prefixed \, + and an unescaped $ is appended as a message delimiter. Then, + socket.send() is called as often as necessary to ensure + message is sent fully, as socket.send() due to buffering may + not send all of it right away. + + Assuming socket is blocking, it's rather improbable that + socket.send() will be partial / return a positive value less + than the (byte) length of msg – but not entirely out of the + question. See: - - + - + + + This also handles a socket.send() return value of 0, which + might be possible or not (?) for blocking sockets: - + + + """ + escaped_message = '' + for char in message: + if char in ('\\', '$'): + escaped_message += '\\' + escaped_message += char + escaped_message += '$' + data = escaped_message.encode() + totalsent = 0 + while totalsent < len(data): + socket_broken = False + try: + sent = self.socket.send(data[totalsent:]) + socket_broken = sent == 0 + except OSError as err: + if err.errno == 9: # "Bad file descriptor", when connection broken + socket_broken = True + else: + raise err + if socket_broken and not silent_connection_break: + raise BrokenSocketConnection + totalsent = totalsent + sent + + def recv(self): + """Get full send()-prepared message from self.socket. + + In detail, socket.recv() is looped over for sequences of bytes + that can be decoded as a Unicode string delimited by an + unescaped $, with \ and $ escapable by \. If a sequence of + characters that ends in an unescaped $ cannot be decoded as + Unicode, None is returned as its representation. Stop once + socket.recv() returns nothing. + + Under the hood, the TCP stack receives packets that construct + the input payload in an internal buffer; socket.recv(BUFSIZE) + pops up to BUFSIZE bytes from that buffer, without knowledge + either about the input's segmentation into packets, or whether + the input is segmented in any other meaningful way; that's why + we do our own message segmentation with $ as a delimiter. + + """ + esc = False + data = b'' + msg = b'' + while True: + data += self.socket.recv(1024) + if 0 == len(data): + return + cut_off = 0 + for c in data: + cut_off += 1 + if esc: + msg += bytes([c]) + esc = False + elif chr(c) == '\\': + esc = True + elif chr(c) == '$': + try: + yield msg.decode() + except UnicodeDecodeError: + yield None + data = data[cut_off:] + msg = b'' + else: + msg += bytes([c]) diff --git a/plom_socket_io.py b/plom_socket_io.py deleted file mode 100644 index ebde3c1..0000000 --- a/plom_socket_io.py +++ /dev/null @@ -1,86 +0,0 @@ -class BrokenSocketConnection(Exception): - pass - - -def send(socket, message): - """Send message via socket, encoded and delimited the way recv() expects. - - In detail, all \ and $ in message are escaped with prefixed \, and an - unescaped $ is appended as a message delimiter. Then, socket.send() is - called as often as necessary to ensure message is sent fully, as - socket.send() due to buffering may not send all of it right away. - - Assuming socket is blocking, it's rather improbable that socket.send() will - be partial / return a positive value less than the (byte) length of msg – - but not entirely out of the question. See: - - - - - - - - This also handles a socket.send() return value of 0, which might be - possible or not (?) for blocking sockets: - - - """ - escaped_message = '' - for char in message: - if char in ('\\', '$'): - escaped_message += '\\' - escaped_message += char - escaped_message += '$' - data = escaped_message.encode() - totalsent = 0 - while totalsent < len(data): - socket_broken = False - try: - sent = socket.send(data[totalsent:]) - socket_broken = sent == 0 - except OSError as err: - if err.errno == 9: # "Bad file descriptor", when connection broken - socket_broken = True - else: - raise err - if socket_broken: - raise BrokenSocketConnection - totalsent = totalsent + sent - - -def recv(socket): - """Get full send()-prepared message from socket. - - In detail, socket.recv() is looped over for sequences of bytes that can be - decoded as a Unicode string delimited by an unescaped $, with \ and $ - escapable by \. If a sequence of characters that ends in an unescaped $ - cannot be decoded as Unicode, None is returned as its representation. Stop - once socket.recv() returns nothing. - - Under the hood, the TCP stack receives packets that construct the input - payload in an internal buffer; socket.recv(BUFSIZE) pops up to BUFSIZE - bytes from that buffer, without knowledge either about the input's - segmentation into packets, or whether the input is segmented in any other - meaningful way; that's why we do our own message segmentation with $ as a - delimiter. - """ - esc = False - data = b'' - msg = b'' - while True: - data += socket.recv(1024) - if 0 == len(data): - return - cut_off = 0 - for c in data: - cut_off += 1 - if esc: - msg += bytes([c]) - esc = False - elif chr(c) == '\\': - esc = True - elif chr(c) == '$': - try: - yield msg.decode() - except UnicodeDecodeError: - yield None - data = data[cut_off:] - msg = b'' - else: - msg += bytes([c]) diff --git a/server_/io.py b/server_/io.py index 501399f..c8f6114 100644 --- a/server_/io.py +++ b/server_/io.py @@ -45,45 +45,39 @@ class IO_Handler(socketserver.BaseRequestHandler): instructions. """ - import plom_socket_io - def caught_send(socket, message): - """Send message by socket, catch broken socket connection error.""" - try: - plom_socket_io.send(socket, message) - except plom_socket_io.BrokenSocketConnection: - pass - - def send_queue_messages(socket, queue_in, thread_alive): + def send_queue_messages(plom_socket, queue_in, thread_alive): """Send messages via socket from queue_in while thread_alive[0].""" while thread_alive[0]: try: msg = queue_in.get(timeout=1) except queue.Empty: continue - caught_send(socket, msg) + plom_socket.send(msg, True) import uuid + import plom_socket + plom_socket = plom_socket.PlomSocket(self.request) print('CONNECTION FROM:', str(self.client_address)) connection_id = uuid.uuid4() queue_in = queue.Queue() self.server.queue_out.put(('ADD_QUEUE', connection_id, queue_in)) thread_alive = [True] t = threading.Thread(target=send_queue_messages, - args=(self.request, queue_in, thread_alive)) + args=(plom_socket, queue_in, thread_alive)) t.start() - for message in plom_socket_io.recv(self.request): + for message in plom_socket.recv(): if message is None: - caught_send(self.request, 'BAD MESSAGE') + plom_socket.send('BAD MESSAGE', True) elif 'QUIT' == message: - caught_send(self.request, 'BYE') + plom_socket.send('BYE', True) break else: self.server.queue_out.put(('COMMAND', connection_id, message)) self.server.queue_out.put(('KILL_QUEUE', connection_id)) thread_alive[0] = False print('CONNECTION CLOSED FROM:', str(self.client_address)) - self.request.close() + plom_socket.socket.close() class GameIO():