#!/usr/bin/env python3
import socketserver
-import plom_socket_io
import threading
-import time
+import queue
+import sys
+import os
+from parser import ArgError, Parser
+from server_.game import World, GameError
+
# Avoid "Address already in use" errors.
socketserver.TCPServer.allow_reuse_address = True
class Server(socketserver.ThreadingTCPServer):
- """Bind together threaded IO handling server and world state (counter)."""
+ """Bind together threaded IO handling server and message queue."""
- def __init__(self, counter, *args, **kwargs):
+ def __init__(self, queue, *args, **kwargs):
super().__init__(*args, **kwargs)
- self.counter = counter
+ self.queue_out = queue
self.daemon_threads = True # Else, server's threads have daemon=False.
-def fib(n):
- """Calculate n-th Fibonacci number."""
- if n in (1, 2):
- return 1
- else:
- return fib(n-1) + fib(n-2)
-
-
class IO_Handler(socketserver.BaseRequestHandler):
def handle(self):
- """Loop recv for input, send replies; also, send regular counter value.
+ """Move messages between network socket and main thread via queues.
+
+ On start, sets up new queue, sends it via self.server.queue_out to
+ main thread, and from then on receives messages to send back from the
+ main thread via that new queue.
- If input is 'QUIT', send reply 'BYE' and end loop / connection.
- Otherwise, use handle_message to interpret and enact commands.
+ At the same time, loops over socket's recv to get messages from the
+ outside via self.server.queue_out into the main thread. Ends connection
+ once a 'QUIT' message is received from socket, and then also kills its
+ own queue.
+
+ All messages to the main thread are tuples, with the first element a
+ meta command ('ADD_QUEUE' for queue creation, 'KILL_QUEUE' for queue
+ deletion, and 'COMMAND' for everything else), the second element a UUID
+ that uniquely identifies the thread (so that the main thread knows whom
+ to send replies back to), and optionally a third element for further
+ instructions.
"""
+ import plom_socket_io
+
def caught_send(socket, message):
"""Send message by socket, catch broken socket connection error."""
try:
except plom_socket_io.BrokenSocketConnection:
pass
- def send_counter_loop(socket, counter, kill):
- """Every 5 seconds, send state of counter[0] until kill[0] set."""
- while not kill[0]:
- caught_send(socket, 'COUNTER ' + str(counter[0]))
- time.sleep(5)
-
- def handle_message(message):
- """Evaluate message for tasks to perform, yield result.
-
- Accepts one command: FIB, followed by positive integers, all tokens
- separated by whitespace. Will calculate and return for each such
- integer n the n-th Fibonacci number. Uses multiprocessing to
- perform multiple such calculations in parallel. Yields a
- 'CALCULATING …' message before the calculation starts, and finally
- yields a message containing the results. (The 'CALCULATING …'
- message coming before the results message is currently the main
- reason this works as a generator function using yield.)
-
- When no command can be read into the message, just yields a 'NO
- COMMAND UNDERSTOOD:', followed by the message.
- """
- from multiprocessing import Pool
- tokens = message.split(' ')
- if tokens[0] == 'FIB':
- msg_fail_fib = 'MALFORMED FIB REQUEST'
- if len(tokens) < 2:
- yield msg_fail_fib
- return
- numbers = []
- for token in tokens[1:]:
- if token != '0' and token.isdigit():
- numbers += [int(token)]
- elif token == '':
- continue
- else:
- yield msg_fail_fib
- return
- yield 'CALCULATING …'
- reply = ''
- with Pool(len(numbers)) as p:
- results = p.map(fib, numbers)
- reply = ' '.join([str(r) for r in results])
- yield reply
- return
- yield 'NO COMMAND UNDERSTOOD: %s' % message
+ def send_queue_messages(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)
+ import uuid
print('CONNECTION FROM:', str(self.client_address))
- counter_loop_killer = [False]
- send_count = threading.Thread(target=send_counter_loop,
- kwargs={'counter': self.server.counter,
- 'socket': self.request,
- 'kill': counter_loop_killer})
- send_count.start()
+ 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))
+ t.start()
for message in plom_socket_io.recv(self.request):
if message is None:
- print('RECEIVED MALFORMED MESSAGE')
- caught_send(self.request, 'bad message')
+ caught_send(self.request, 'BAD MESSAGE')
elif 'QUIT' == message:
caught_send(self.request, 'BYE')
break
else:
- print('RECEIVED MESSAGE:', message)
- for reply in handle_message(message):
- caught_send(self.request, reply)
- counter_loop_killer = [True]
- print('CONNECTION CLOSED:', str(self.client_address))
+ 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()
-def inc_loop(counter, interval):
- """Loop incrementing counter every interval seconds."""
+def fib(n):
+ """Calculate n-th Fibonacci number. Very inefficiently."""
+ if n in (1, 2):
+ return 1
+ else:
+ return fib(n-1) + fib(n-2)
+
+
+class CommandHandler:
+
+ def __init__(self, queues_out={}):
+ from multiprocessing import Pool
+ self.queues_out = queues_out
+ self.world = World()
+ self.parser = Parser(self)
+ # self.pool and self.pool_result are currently only needed by the FIB
+ # command and the demo of a parallelized game loop in cmd_inc_p.
+ self.pool = Pool()
+ self.pool_result = None
+
+ def handle_input(self, input_, connection_id=None, abort_on_error=False):
+ """Process input_ to command grammar, call command handler if found."""
+ try:
+ command = self.parser.parse(input_)
+ if command is None:
+ self.send_to(connection_id, 'UNHANDLED INPUT')
+ else:
+ command(connection_id=connection_id)
+ except ArgError as e:
+ self.send_to(connection_id, 'ARGUMENT ERROR: ' + str(e))
+ if abort_on_error:
+ exit(1)
+ except GameError as e:
+ self.send_to(connection_id, 'GAME ERROR: ' + str(e))
+ if abort_on_error:
+ exit(1)
+
+ def send_to(self, connection_id, msg):
+ """Send msg to client of connection_id; if no later, print instead."""
+ if connection_id:
+ self.queues_out[connection_id].put(msg)
+ else:
+ print(msg)
+
+ def send_all(self, msg):
+ """Send msg to all clients."""
+ for connection_id in self.queues_out:
+ self.send_to(connection_id, msg)
+
+ def stringify_yx(self, tuple_):
+ """Transform tuple (y,x) into string 'Y:'+str(y)+',X:'+str(x)."""
+ return 'Y:' + str(tuple_[0]) + ',X:' + str(tuple_[1])
+
+ def quoted(self, string):
+ """Quote and escape string so client interprets it as single token."""
+ quoted = []
+ quoted += ['"']
+ for c in string:
+ if c in {'"', '\\'}:
+ quoted += ['\\']
+ quoted += [c]
+ quoted += ['"']
+ return ''.join(quoted)
+
+ def send_all_gamestate(self):
+ """Send out game state data relevant to clients."""
+ self.send_all('NEW_TURN ' + str(self.world.turn))
+ self.send_all('MAP_SIZE ' + self.stringify_yx(self.world.map_size))
+ for y in range(self.world.map_size[0]):
+ width = self.world.map_size[1]
+ terrain_line = self.world.map_[y * width:(y + 1) * width]
+ self.send_all('TERRAIN_LINE %5s %s' % (y, self.quoted(terrain_line)))
+ for thing in self.world.things:
+ self.send_all('THING TYPE:' + thing.type_ + ' '
+ + self.stringify_yx(thing.position))
+
+ def proceed(self):
+ """Send turn finish signal, run game world, send new world data.
+
+ First sends 'TURN_FINISHED' message, then runs game world
+ until new player input is needed, then sends game state.
+ """
+ self.send_all('TURN_FINISHED ' + str(self.world.turn))
+ self.world.proceed_to_next_player_turn()
+ self.send_all_gamestate()
+
+ def cmd_MOVE(self, direction, connection_id):
+ """Set player task to 'move' with direction arg, finish player turn."""
+ if direction not in {'UP', 'DOWN', 'RIGHT', 'LEFT'}:
+ raise ArgError('Move argument must be one of: '
+ 'UP, DOWN, RIGHT, LEFT')
+ self.world.player.set_task('move', direction=direction)
+ self.proceed()
+ cmd_MOVE.argtypes = 'string'
+
+ def cmd_WAIT(self, connection_id):
+ """Set player task to 'wait', finish player turn."""
+ self.world.player.set_task('wait')
+ self.proceed()
+
+ def cmd_GET_TURN(self, connection_id):
+ """Send world.turn to caller."""
+ self.send_to(connection_id, str(self.world.turn))
+
+ def cmd_ECHO(self, msg, connection_id):
+ """Send msg to caller."""
+ self.send_to(connection_id, msg)
+ cmd_ECHO.argtypes = 'string'
+
+ def cmd_ALL(self, msg, connection_id):
+ """Send msg to all clients."""
+ self.send_all(msg)
+ cmd_ALL.argtypes = 'string'
+
+ def cmd_FIB(self, numbers, connection_id):
+ """Reply with n-th Fibonacci numbers, n taken from tokens[1:].
+
+ Numbers are calculated in parallel as far as possible, using fib().
+ A 'CALCULATING …' message is sent to caller before the result.
+ """
+ self.send_to(connection_id, 'CALCULATING …')
+ results = self.pool.map(fib, numbers)
+ reply = ' '.join([str(r) for r in results])
+ self.send_to(connection_id, reply)
+ cmd_FIB.argtypes = 'seq:int:nonneg'
+
+ def cmd_INC_P(self, connection_id):
+ """Increment world.turn, send game turn data to everyone.
+
+ To simulate game processing waiting times, a one second delay between
+ TURN_FINISHED and NEW_TURN occurs; after NEW_TURN, some expensive
+ calculations are started as pool processes that need to be finished
+ until a further INC finishes the turn.
+
+ This is just a demo structure for how the game loop could work when
+ parallelized. One might imagine a two-step game turn, with a non-action
+ step determining actor tasks (the AI determinations would take the
+ place of the fib calculations here), and an action step wherein these
+ tasks are performed (where now sleep(1) is).
+ """
+ from time import sleep
+ if self.pool_result is not None:
+ self.pool_result.wait()
+ self.send_all('TURN_FINISHED ' + str(self.world.turn))
+ sleep(1)
+ self.world.turn += 1
+ self.send_all_gamestate()
+ self.pool_result = self.pool.map_async(fib, (35, 35))
+
+
+def io_loop(q, commander):
+ """Handle commands coming through queue q, send results back.
+
+ Commands from q are expected to be tuples, with the first element either
+ 'ADD_QUEUE', 'COMMAND', or 'KILL_QUEUE', the second element a UUID, and
+ an optional third element of arbitrary type. The UUID identifies a
+ receiver for replies.
+
+ An 'ADD_QUEUE' command should contain as third element a queue through
+ which to send messages back to the sender of the command. A 'KILL_QUEUE'
+ command removes the queue for that receiver from the list of queues through
+ which to send replies.
+
+ A 'COMMAND' command is specified in greater detail by a string that is the
+ tuple's third element. The commander CommandHandler takes care of processing
+ this and sending out replies.
+ """
while True:
- time.sleep(interval)
- counter[0] += 1
+ x = q.get()
+ command_type = x[0]
+ connection_id = x[1]
+ content = None if len(x) == 2 else x[2]
+ if command_type == 'ADD_QUEUE':
+ commander.queues_out[connection_id] = content
+ elif command_type == 'COMMAND':
+ commander.handle_input(content, connection_id)
+ elif command_type == 'KILL_QUEUE':
+ del commander.queues_out[connection_id]
-counter = [0]
-b = threading.Thread(target=inc_loop, daemon=True, kwargs={'counter': counter,
- 'interval': 1})
-b.start()
-server = Server(counter, ('localhost', 5000), IO_Handler)
+if len(sys.argv) != 2:
+ print('wrong number of arguments, expected one (game file)')
+ exit(1)
+game_file_name = sys.argv[1]
+commander = CommandHandler()
+if os.path.exists(game_file_name):
+ if not os.path.isfile(game_file_name):
+ print('game file name does not refer to a valid game file')
+ else:
+ with open(game_file_name, 'r') as f:
+ lines = f.readlines()
+ for i in range(len(lines)):
+ line = lines[i]
+ print("FILE INPUT LINE %s: %s" % (i, line), end='')
+ commander.handle_input(line, abort_on_error=True)
+q = queue.Queue()
+c = threading.Thread(target=io_loop, daemon=True, args=(q, commander))
+c.start()
+server = Server(q, ('localhost', 5000), IO_Handler)
try:
server.serve_forever()
except KeyboardInterrupt: