diff options
Diffstat (limited to 'catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py')
| -rw-r--r-- | catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py b/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py new file mode 100644 index 00000000..1fe5c2ad --- /dev/null +++ b/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py @@ -0,0 +1,184 @@ +# Copyright 2014 The Chromium Authors. All rights reserved. +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + +import errno +import json +import logging +import socket +import time + +from telemetry.core import exceptions +from telemetry.internal.backends.chrome_inspector import websocket + +class WebSocketDisconnected(exceptions.Error): + """An attempt was made to use a web socket after it had been disconnected.""" + pass + + +class InspectorWebsocket(object): + + # See http://www.jsonrpc.org/specification#error_object. + METHOD_NOT_FOUND_CODE = -32601 + + def __init__(self): + """Create a websocket handler for communicating with Inspectors.""" + self._socket = None + self._cur_socket_timeout = 0 + self._next_request_id = 0 + self._domain_handlers = {} + self._pending_callbacks = dict() + + def RegisterDomain(self, domain_name, notification_handler): + """Registers a given domain for handling notification methods. + + For example, given inspector_backend: + def OnConsoleNotification(msg): + if msg['method'] == 'Console.messageAdded': + print msg['params']['message'] + inspector_backend.RegisterDomain('Console', OnConsoleNotification) + + Args: + domain_name: The devtools domain name. E.g., 'Tracing', 'Memory', 'Page'. + notification_handler: Handler for devtools notification. Will be + called if a devtools notification with matching domain is received + via DispatchNotifications. The handler accepts a single paramater: + the JSON object representing the notification. + """ + assert domain_name not in self._domain_handlers + self._domain_handlers[domain_name] = notification_handler + + def UnregisterDomain(self, domain_name): + """Unregisters a previously registered domain.""" + assert domain_name in self._domain_handlers + del self._domain_handlers[domain_name] + + def Connect(self, url, timeout): + """Connects the websocket. + + Raises: + websocket.WebSocketException + socket.error + """ + assert not self._socket + self._socket = websocket.create_connection(url, timeout=timeout) + self._cur_socket_timeout = 0 + self._next_request_id = 0 + + def Disconnect(self): + """Disconnects the inspector websocket. + + Raises: + websocket.WebSocketException + socket.error + """ + if self._socket: + self._socket.close() + self._socket = None + + def SendAndIgnoreResponse(self, req): + """Sends a request without waiting for a response. + + Raises: + websocket.WebSocketException: Error from websocket library. + socket.error: Error from websocket library. + exceptions.WebSocketDisconnected: The socket was disconnected. + """ + self._SendRequest(req) + + def _SendRequest(self, req): + if not self._socket: + raise WebSocketDisconnected() + req['id'] = self._next_request_id + self._next_request_id += 1 + data = json.dumps(req) + self._socket.send(data) + if logging.getLogger().isEnabledFor(logging.DEBUG): + logging.debug('sent [%s]', json.dumps(req, indent=2, sort_keys=True)) + + def SyncRequest(self, req, timeout): + """Sends a request and waits for a response. + + Raises: + websocket.WebSocketException: Error from websocket library. + socket.error: Error from websocket library. + exceptions.WebSocketDisconnected: The socket was disconnected. + """ + self._SendRequest(req) + + while True: + res = self._Receive(timeout) + if 'id' in res and res['id'] == req['id']: + return res + + def AsyncRequest(self, req, callback): + """Sends an async request and returns immediately. + + Response will be handled in the |callback| later when DispatchNotifications + is invoked. + + Args: + callback: a function that takes inspector's response as the argument. + """ + self._SendRequest(req) + self._pending_callbacks[req['id']] = callback + + def DispatchNotifications(self, timeout): + """Waits for responses from the websocket, dispatching them as necessary. + + Raises: + websocket.WebSocketException: Error from websocket library. + socket.error: Error from websocket library. + exceptions.WebSocketDisconnected: The socket was disconnected. + """ + self._Receive(timeout) + + def _SetTimeout(self, timeout): + if self._cur_socket_timeout != timeout: + self._socket.settimeout(timeout) + self._cur_socket_timeout = timeout + + def _Receive(self, timeout): + if not self._socket: + raise WebSocketDisconnected() + + self._SetTimeout(timeout) + + while True: + try: + data = self._socket.recv() + except socket.error, e: + if e.errno == errno.EAGAIN: + # Resource is temporarily unavailable. Try again. + # See https://code.google.com/p/chromium/issues/detail?id=545853#c3 + # for more details. + time.sleep(0.1) + else: + raise + else: + break + + result = json.loads(data) + if logging.getLogger().isEnabledFor(logging.DEBUG): + logging.debug( + 'got [%s]', json.dumps(result, indent=2, sort_keys=True)) + if 'method' in result: + self._HandleNotification(result) + elif 'id' in result: + self._HandleAsyncResponse(result) + return result + + def _HandleNotification(self, result): + mname = result['method'] + dot_pos = mname.find('.') + domain_name = mname[:dot_pos] + if not domain_name in self._domain_handlers: + logging.warn('Unhandled inspector message: %s', result) + return + + self._domain_handlers[domain_name](result) + + def _HandleAsyncResponse(self, result): + callback = self._pending_callbacks.pop(result['id'], None) + if callback: + callback(result) |