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Diffstat (limited to 'fg21sim/webui/handlers/websocket.py')
| -rw-r--r-- | fg21sim/webui/handlers/websocket.py | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/fg21sim/webui/handlers/websocket.py b/fg21sim/webui/handlers/websocket.py new file mode 100644 index 0000000..7db953c --- /dev/null +++ b/fg21sim/webui/handlers/websocket.py @@ -0,0 +1,436 @@ +# Copyright (c) 2016 Weitian LI <liweitianux@live.com> +# MIT license + +""" +Communicate with the "fg21sim" simulation program through the Web UI using +the WebSocket_ protocol, which provides full-duplex communication channels +over a single TCP connection. + +.. _WebSocket: https://en.wikipedia.org/wiki/WebSocket + + +References +---------- +- Tornado WebSocket: + http://www.tornadoweb.org/en/stable/websocket.html +- Can I Use: WebSocket: + http://caniuse.com/#feat=websockets +""" + +import os +import json +import logging + +import tornado.websocket +from tornado.options import options + +from .console import ConsoleHandler +from ..utils import get_host_ip, ip_in_network +from ...errors import ConfigError + + +logger = logging.getLogger(__name__) + + +class FG21simWSHandler(tornado.websocket.WebSocketHandler): + """ + WebSocket for bi-directional communication between the Web UI and + the server, which can deal with the configurations and execute the + simulation task. + + Generally, WebSocket send and receive data as *string*. Therefore, + the more complex data are stringified as JSON string before sending, + which will be parsed after receive. + + Each message (as a JSON object or Python dictionary) has a ``type`` + field which will be used to determine the following action to take. + + Attributes + ---------- + name : str + Name to distinguish this WebSocket handle. + from_localhost : bool + Set to ``True`` if the access is from the localhost, + otherwise ``False``. + configs : `~ConfigManager` + A ``ConfigManager`` instance, for configuration manipulations when + communicating with the Web UI. + """ + name = "fg21sim" + from_localhost = None + + def check_origin(self, origin): + """Check the origin of the WebSocket access. + + Attributes + ---------- + from_localhost : bool + Set to ``True`` if the access is from the localhost, + otherwise ``False``. + + NOTE + ---- + Currently, only allow access from the ``localhost`` + (i.e., 127.0.0.1) and local LAN. + """ + self.from_localhost = False + logger.info("WebSocket: {0}: origin: {1}".format(self.name, origin)) + ip = get_host_ip(url=origin) + network = options.hosts_allowed + if ip == "127.0.0.1": + self.from_localhost = True + allow = True + logger.info("WebSocket: %s: origin is localhost" % self.name) + elif network.upper() == "ANY": + # Any hosts are allowed + allow = True + logger.warning("WebSocket: %s: any hosts are allowed" % self.name) + elif ip_in_network(ip, network): + allow = True + logger.info("WebSocket: %s: " % self.name + + "client is in the allowed network: %s" % network) + else: + allow = False + logger.error("WebSocket: %s: " % self.name + + "client is NOT in the allowed network: %s" % network) + return allow + + def open(self): + """Invoked when a new WebSocket is opened by the client.""" + # FIXME: + # * better to move to the `Application` class ?? + # * or create a ``ConfigsHandler`` similar to the ``ConsoleHandler`` + self.configs = self.application.configmanager + self.console_handler = ConsoleHandler(websocket=self) + # + logger.info("WebSocket: {0}: opened".format(self.name)) + logger.info("Allowed hosts: {0}".format(options.hosts_allowed)) + + def on_close(self): + """Invoked when a new WebSocket is closed by the client.""" + code, reason = None, None + if hasattr(self, "close_code"): + code = self.close_code + if hasattr(self, "close_reason"): + reason = self.close_reason + logger.info("WebSocket: {0}: closed by client: {1}, {2}".format( + self.name, code, reason)) + + # FIXME/XXX: + # * How to be non-blocking ?? + # NOTE: WebSocket.on_message: may NOT be a coroutine at the moment (v4.3) + # References: + # [1] https://stackoverflow.com/a/35543856/4856091 + # [2] https://stackoverflow.com/a/33724486/4856091 + def on_message(self, message): + """Handle incoming messages and dispatch task according to the + message type. + + NOTE + ---- + The received message (parsed to a Python dictionary) has a ``type`` + item which will be used to determine the following action to take. + + Currently supported message types are: + ``configs``: + Request or set the configurations + ``console``: + Control the simulation tasks, or request logging messages + ``results``: + Request the simulation results + + The sent message also has a ``type`` item of same value, which the + client can be used to figure out the proper actions. + There is a ``success`` item which indicates the status of the + requested operation, and an ``error`` recording the error message + if ``success=False``. + """ + logger.debug("WebSocket: %s: received: %s" % (self.name, message)) + try: + msg = json.loads(message) + msg_type = msg["type"] + except json.JSONDecodeError: + logger.warning("WebSocket: {0}: ".format(self.name) + + "message is not a valid JSON string") + response = {"success": False, + "type": None, + "error": "message is not a valid JSON string"} + except (KeyError, TypeError): + logger.warning("WebSocket: %s: skip invalid message" % self.name) + response = {"success": False, + "type": None, + "error": "type is missing"} + else: + # Check the message type and dispatch task + if msg_type == "configs": + # Request or set the configurations + response = self._handle_configs(msg) + elif msg_type == "console": + # Control the simulation tasks, or request logging messages + # FIXME/XXX: + # * How to make this asynchronously ?? + response = self.console_handler.handle_message(msg) + elif msg_type == "results": + # Request the simulation results + response = self._handle_results(msg) + else: + # Message of unknown type + logger.warning("WebSocket: {0}: ".format(self.name) + + "unknown message type: {0}".format(msg_type)) + response = {"success": False, + "type": msg_type, + "error": "unknown message type %s" % msg_type} + # + msg_response = json.dumps(response) + self.write_message(msg_response) + + def _handle_configs(self, msg): + """Handle the message of type "configs", which request to get or + set some configurations by the client. + + TODO: + * improve the description ... + * split these handling functions into a separate class in a module + + Parameters + ---------- + msg : dict + A dictionary parsed from the incoming JSON message, which + generally has the following syntax: + ``{"type": "configs", "action": <action>, "data": <data>}`` + where the ``<action>`` is ``set`` or ``get``, and the ``<data>`` + is a list of config keys or a dict of config key-value pairs. + + Returns + ------- + response : dict + A dictionary parsed from the incoming JSON message, which + generally has the following syntax: + ``{"type": "configs", "action": <action>, + "data": <data>, "errors": <errors>}`` + where the ``<action>`` is the same as input, the ``<data>`` is + a list of config keys or a dict of config key-value pairs, and + ``<errors>`` contains the error message for the invalid config + values. + """ + try: + msg_type = msg["type"] + msg_action = msg["action"] + response = {"type": msg_type, "action": msg_action} + logger.info("WebSocket: {0}: handle message: ".format(self.name) + + "type: {0}, action: {1}".format(msg_type, msg_action)) + if msg_action == "get": + # Get the values of the specified options + try: + data, errors = self._get_configs(keys=msg["keys"]) + response["success"] = True + response["data"] = data + response["errors"] = errors + except KeyError: + response["success"] = False + response["error"] = "'keys' is missing" + elif msg_action == "set": + # Set the values of the specified options + try: + errors = self._set_configs(data=msg["data"]) + response["success"] = True + response["data"] = {} # be more consistent + response["errors"] = errors + except KeyError: + response["success"] = False + response["error"] = "'data' is missing" + elif msg_action == "reset": + # Reset the configurations to the defaults + self._reset_configs() + response["success"] = True + elif msg_action == "load": + # Load the supplied user configuration file + try: + success, error = self._load_configs(msg["userconfig"]) + response["success"] = success + if not success: + response["error"] = error + except KeyError: + response["success"] = False + response["error"] = "'userconfig' is missing" + elif msg_action == "save": + # Save current configurations to file + try: + success, error = self._save_configs(msg["outfile"], + msg["clobber"]) + response["success"] = success + if not success: + response["error"] = error + except KeyError: + response["success"] = False + response["error"] = "'outfile' or 'clobber' is missing" + else: + logger.warning("WebSocket: {0}: ".format(self.name) + + "unknown action: {0}".format(msg_action)) + response["success"] = False + response["error"] = "unknown action: {0}".format(msg_action) + except KeyError: + # Received message has wrong syntax/format + response = {"success": False, + "type": msg_type, + "error": "no action specified"} + # + logger.debug("WebSocket: {0}: ".format(self.name) + + "response: {0}".format(response)) + return response + + def _get_configs(self, keys=None): + """Get the values of the config options specified by the given keys. + + Parameters + ---------- + keys : list[str], optional + A list of keys specifying the config options whose values will + be obtained. + If ``keys=None``, then all the configurations values are dumped. + + Returns + ------- + data : dict + A dictionary with keys the same as the input keys, and values + the corresponding config option values. + errors : dict + When error occurs (e.g., invalid key), then the specific errors + with details are stored in this dictionary. + + NOTE + ---- + Do not forget the ``userconfig`` option. + """ + if keys is None: + # Dump all the configurations + data = self.configs.dump(flatten=True) + data["userconfig"] = self.configs.userconfig + errors = {} + else: + data = {} + errors = {} + for key in keys: + if key == "userconfig": + data["userconfig"] = self.configs.userconfig + else: + try: + data[key] = self.configs.getn(key) + except KeyError as e: + errors[key] = str(e) + # + return (data, errors) + + def _set_configs(self, data): + """Set the values of the config options specified by the given keys + to the corresponding supplied data. + + NOTE + ---- + The ``userconfig`` needs special handle. + The ``workdir`` and ``configfile`` options should be ignored. + + Parameters + ---------- + data : dict + A dictionary of key-value pairs, with keys specifying the config + options whose value will be changed, and values the new values + to which config options will be set. + NOTE: + If want to set the ``userconfig`` option, an *absolute path* + must be provided. + + Returns + ------- + errors : dict + When error occurs (e.g., invalid key, invalid values), then the + specific errors with details are stored in this dictionary. + """ + errors = {} + for key, value in data.items(): + if key in ["workdir", "configfile"]: + # Ignore "workdir" and "configfile" + continue + elif key == "userconfig": + if os.path.isabs(os.path.expanduser(value)): + self.configs.userconfig = value + else: + errors[key] = "Not an absolute path" + else: + try: + self.configs.setn(key, value) + except KeyError as e: + errors[key] = str(e) + # NOTE: + # Check the whole configurations after all provided options are + # updated, and merge the validation errors. + __, cherr = self.configs.check_all(raise_exception=False) + errors.update(cherr) + return errors + + def _reset_configs(self): + """Reset the configurations to the defaults.""" + self.configs.reset() + + def _load_configs(self, userconfig): + """Load configurations from the provided user configuration file. + + Parameters + ---------- + userconfig: str + The filepath to the user configuration file, which must be + an *absolute path*. + + Returns + ------- + success : bool + ``True`` if the operation succeeded, otherwise, ``False``. + error : str + If failed, this ``error`` saves the details, otherwise, ``None``. + """ + success = False + error = None + if os.path.isabs(os.path.expanduser(userconfig)): + try: + self.configs.read_userconfig(userconfig) + success = True + except ConfigError as e: + error = str(e) + else: + error = "Not an absolute path" + return (success, error) + + def _save_configs(self, outfile, clobber=False): + """Save current configurations to file. + + Parameters + ---------- + outfile: str + The filepath to the output configuration file, which must be + an *absolute path*. + clobber : bool, optional + Whether overwrite the output file if already exists? + + Returns + ------- + success : bool + ``True`` if the operation succeeded, otherwise, ``False``. + error : str + If failed, this ``error`` saves the details, otherwise, ``None``. + """ + success = False + error = None + try: + self.configs.save(outfile, clobber=clobber) + success = True + except (ValueError, OSError) as e: + error = str(e) + return (success, error) + + def _handle_results(self, msg): + # Got a message of supported types + msg_type = msg["type"] + logger.info("WebSocket: {0}: ".format(self.name) + + "handle message of type: {0}".format(msg_type)) + response = {"success": True, "type": msg_type} + return response |