Source code for textworld.render.serve

# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT license.

Creates server for streamed game state
import os
import json
import logging
import textwrap
from os.path import join as pjoin

from multiprocessing import Process, Pipe
from multiprocessing.connection import Connection
from threading import Thread
from queue import Queue

from textworld.core import GameState
from textworld.utils import check_modules
import textworld.render

# Try importing optional libraries.
missing_modules = []
    import webbrowser
except ImportError:

    import flask
    from flask import Flask, request
except ImportError:

    import gevent
    from gevent import pywsgi
except ImportError:

    import pybars
except ImportError:

WEB_SERVER_RESOURCES = pjoin(os.path.abspath(os.path.dirname(__file__)), "tmpl")

[docs]def get_html_template(game_state=None): check_modules(["pybars"], missing_modules) # read in template compiler = pybars.Compiler() with open(pjoin(WEB_SERVER_RESOURCES, 'slideshow.handlebars'), 'r') as f: contents = template = compiler.compile(contents) if game_state is None: return template html = template({ 'game_state': game_state, 'template_path': WEB_SERVER_RESOURCES, }) return html
[docs]class ServerSentEvent: def __init__(self, data: any): """ Object helper to parse dict into SSE data. :param data: data to pass to SSE """ = data self.event = None = None self.desc_map = { "data", self.event: "event", "id" }
[docs] def encode(self): if not return "" lines = ["%s: %s" % (v, k) for k, v in self.desc_map.items() if k] return "%s\n\n" % "\n".join(lines)
[docs]class SupressStdStreams: def __init__(self): """ for surpressing std.out streams """ self._null_fds = [, os.O_RDWR) for _ in range(2)] self._save_fds = [os.dup(1), os.dup(2)] def __enter__(self): os.dup2(self._null_fds[0], 1) os.dup2(self._null_fds[1], 2) def __exit__(self, *_): os.dup2(self._save_fds[0], 1) os.dup2(self._save_fds[1], 2) for fd in self._null_fds + self._save_fds: os.close(fd)
[docs]def find_free_port(port_range): import socket from contextlib import closing for port in port_range: with closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as s: try: s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.bind(("", port)) return s.getsockname()[1] except socket.error: continue raise ValueError("Could not find any available port.")
[docs]class VisualizationService: """ Server for visualization. We instantiate a new process for our flask server, so our game can send updates to the server. The server instantiates new gevent Queues for every connection. """ def __init__(self, game_state: GameState, open_automatically: bool): self.prev_state = None self.command = None self._process = None state_dict = textworld.render.load_state_from_game_state(game_state) self._history = '<p class="objective-text">{}</p>'.format(game_state.objective.strip().replace("\n", "<br/>")) banner = textwrap.dedent(r""" ________ __ __ | \| \ _ | \ \$$$$$$$$| $$ / \ | $$ | $$ | $$/ $\| $$ | $$ | $$ $$$\ $$ | $$ | $$ $$\$$\$$ | $$ | $$$$ \$$$$ | $$ | $$$ \$$$ \$$ \$$ \$$ """) # noqa: W605 feedback =, 1)[-1] initial_description = banner.replace(" ", "&nbsp;") + feedback self._history += '<p class="feedback-text">{}</p>'.format(initial_description.strip().replace("\n", "<br/>")) state_dict["history"] = self._history state_dict["command"] = "" self.parent_conn, self.child_conn = Pipe() self.game_state = state_dict self.open_automatically = open_automatically
[docs] def start_server(self, game_state: dict, port: int, child_conn: Connection): """ function for starting new server on new process. :param game_state: initial game state from load :param port: port to run server :param child_conn: child connection from multiprocessing.Pipe """ server = Server(game_state, port) server.start(child_conn)
[docs] def start(self, parent_thread: Thread, port: int) -> None: """ Start visualization server on a new process. :param parent_thread: the parent thread that called start. :param port: Port to run visualization on. """ def wait_task(): parent_thread.join() self.stop_server() # Check if address is available. self.port = find_free_port(range(port, port + 100)) self._process = Process(target=self.start_server, name='flask', args=(self.game_state, self.port, self.child_conn)) self._process.start() thread = Thread(target=wait_task, name='waiting_on_parent_exit') thread.start() print("Viewer started at http://localhost:{}.".format(self.port)) if self.open_automatically: check_modules(["webbrowser"], missing_modules) with SupressStdStreams():"http://localhost:{}/".format(self.port))
[docs] def update_state(self, game_state: GameState, command: str): """ Propogate state update to server. We use a multiprocessing.Pipe to pass state into flask process. :param game_state: Glulx game state. :param command: previous command """ state_dict = textworld.render.load_state_from_game_state(game_state) self._history += '<p class="command-text">> {}</p>'.format(command) self._history += '<p class="feedback-text">{}</p>'.format("\n", "<br/>")) state_dict["command"] = command state_dict["history"] = self._history self.parent_conn.send(state_dict)
[docs] def stop_server(self): self._process.terminate()
[docs]class Server: """ Visualization server. Uses Server-sent Events to update game_state for visualization. """ def __init__(self, game_state: dict, port: int): """ Note: Flask routes are defined in app.add_url_rule in order to call `self` in routes. :param game_state: game state returned from load_state_from_game_state :param port: port to run visualization on """ check_modules(["gevent", "flask"], missing_modules) super().__init__() # disabling loggers log = logging.getLogger('werkzeug') log.disabled = True self.port = port self.results = Queue() self.subscribers = [] self.game_state = game_state = Flask(__name__, static_folder=pjoin(WEB_SERVER_RESOURCES, 'static'))'/', 'index', self.index)'/subscribe', 'subscribe', self.subscribe) self.slideshow_template = get_html_template()
[docs] def start(self, child_conn: Connection): """ Starts the WSGI server and listen for updates on a separate thread. :param child_conn: Child connection from `multiprocessing.Pipe`. """ thread = Thread(target=self.listen, name='updates', args=(child_conn, self.results)) thread.start() server = pywsgi.WSGIServer(("", self.port),, log=None) server.serve_forever()
[docs] @staticmethod def listen(conn: Connection, results: Queue): """ Listener for updates. Runs on separate thread. :param conn: child connection from multiprocessing.Pipe. :param results: thread-safe queue for results. """ while True: game_state = conn.recv() results.put(game_state)
[docs] def update_subscribers(self, game_state: dict): """ Updates all subscribers and updates their data. This is for multiple subscribers on the visualization service. :param game_state: parsed game_state from load_state_from_game_state """ def notify(): self.game_state = game_state if len(self.subscribers) == 0: print("We have no subscribers!") else: for q in self.subscribers[:]: q.put(game_state) gevent.spawn(notify)
[docs] def index(self) -> str: """ Index route ("/"). Returns HTML template processed by handlebars. :return: Flask response object """ output = self.slideshow_template({ 'game_state': json.dumps(self.game_state), 'template_path': 'http://' + }) resp = flask.Response(output.encode('utf-8')) resp.headers['Content-Type'] = 'text/html;charset=utf-8' return resp
[docs] def gen(self): """ Our generator for listening for updating state. We poll for results to return us something. If nothing is returned then we just pass and keep polling. :return: yields event-stream parsed data. """ q = gevent.queue.Queue() self.subscribers.append(q) try: while True: self.update_subscribers(self.results.get_nowait()) result = q.get() ev = ServerSentEvent(json.dumps(result)) yield ev.encode() except Exception: pass
[docs] def subscribe(self): """ Our Server-sent Event stream route. :return: A stream """ return flask.Response(self.gen(), mimetype='text/event-stream')