예제 #1
0
 def __init__(self, from_json):
     self.from_json = from_json
     self.api = PyDevdAPI()
     self._options = DebugOptions()
     self._next_breakpoint_id = partial(next, itertools.count(0))
     self._goto_targets_map = IDMap()
     self._launch_or_attach_request_done = False
예제 #2
0
class PyDevJsonCommandProcessor(object):
    def __init__(self, from_json):
        self.from_json = from_json
        self.api = PyDevdAPI()
        self._options = DebugOptions()
        self._next_breakpoint_id = partial(next, itertools.count(0))
        self._goto_targets_map = IDMap()
        self._launch_or_attach_request_done = False

    def process_net_command_json(self,
                                 py_db,
                                 json_contents,
                                 send_response=True):
        '''
        Processes a debug adapter protocol json command.
        '''

        DEBUG = False

        try:
            if isinstance(json_contents, bytes):
                json_contents = json_contents.decode('utf-8')

            request = self.from_json(json_contents, update_ids_from_dap=True)
        except Exception as e:
            try:
                loaded_json = json.loads(json_contents)
                request = Request(loaded_json.get('command', '<unknown>'),
                                  loaded_json['seq'])
            except:
                # There's not much we can do in this case...
                pydev_log.exception('Error loading json: %s', json_contents)
                return

            error_msg = str(e)
            if error_msg.startswith("'") and error_msg.endswith("'"):
                error_msg = error_msg[1:-1]

            # This means a failure processing the request (but we were able to load the seq,
            # so, answer with a failure response).
            def on_request(py_db, request):
                error_response = {
                    'type': 'response',
                    'request_seq': request.seq,
                    'success': False,
                    'command': request.command,
                    'message': error_msg,
                }
                return NetCommand(CMD_RETURN, 0, error_response, is_json=True)

        else:
            if DebugInfoHolder.DEBUG_RECORD_SOCKET_READS and DebugInfoHolder.DEBUG_TRACE_LEVEL >= 1:
                pydev_log.info('Process %s: %s\n' % (
                    request.__class__.__name__,
                    json.dumps(request.to_dict(), indent=4, sort_keys=True),
                ))

            assert request.type == 'request'
            method_name = 'on_%s_request' % (request.command.lower(), )
            on_request = getattr(self, method_name, None)
            if on_request is None:
                print(
                    'Unhandled: %s not available in PyDevJsonCommandProcessor.\n'
                    % (method_name, ))
                return

            if DEBUG:
                print(
                    'Handled in pydevd: %s (in PyDevJsonCommandProcessor).\n' %
                    (method_name, ))

        with py_db._main_lock:
            if request.__class__ == PydevdAuthorizeRequest:
                authorize_request = request  # : :type authorize_request: PydevdAuthorizeRequest
                access_token = authorize_request.arguments.debugServerAccessToken
                py_db.authentication.login(access_token)

            if not py_db.authentication.is_authenticated():
                response = Response(request.seq,
                                    success=False,
                                    command=request.command,
                                    message='Client not authenticated.',
                                    body={})
                cmd = NetCommand(CMD_RETURN, 0, response, is_json=True)
                py_db.writer.add_command(cmd)
                return

            cmd = on_request(py_db, request)
            if cmd is not None and send_response:
                py_db.writer.add_command(cmd)

    def on_pydevdauthorize_request(self, py_db, request):
        client_access_token = py_db.authentication.client_access_token
        body = {'clientAccessToken': None}
        if client_access_token:
            body['clientAccessToken'] = client_access_token

        response = pydevd_base_schema.build_response(request,
                                                     kwargs={'body': body})
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_initialize_request(self, py_db, request):
        body = Capabilities(
            # Supported.
            supportsConfigurationDoneRequest=True,
            supportsConditionalBreakpoints=True,
            supportsHitConditionalBreakpoints=True,
            supportsEvaluateForHovers=True,
            supportsSetVariable=True,
            supportsGotoTargetsRequest=True,
            supportsCompletionsRequest=True,
            supportsModulesRequest=True,
            supportsExceptionOptions=True,
            supportsValueFormattingOptions=True,
            supportsExceptionInfoRequest=True,
            supportTerminateDebuggee=True,
            supportsDelayedStackTraceLoading=True,
            supportsLogPoints=True,
            supportsSetExpression=True,
            supportsTerminateRequest=True,
            exceptionBreakpointFilters=[
                {
                    'filter': 'raised',
                    'label': 'Raised Exceptions',
                    'default': False
                },
                {
                    'filter': 'uncaught',
                    'label': 'Uncaught Exceptions',
                    'default': True
                },
            ],

            # Not supported.
            supportsFunctionBreakpoints=False,
            supportsStepBack=False,
            supportsRestartFrame=False,
            supportsStepInTargetsRequest=False,
            supportsRestartRequest=False,
            supportsLoadedSourcesRequest=False,
            supportsTerminateThreadsRequest=False,
            supportsDataBreakpoints=False,
            supportsReadMemoryRequest=False,
            supportsDisassembleRequest=False,
            additionalModuleColumns=[],
            completionTriggerCharacters=[],
            supportedChecksumAlgorithms=[],
        ).to_dict()

        # Non-standard capabilities/info below.
        body['supportsDebuggerProperties'] = True

        body['pydevd'] = pydevd_info = {}
        pydevd_info['processId'] = os.getpid()
        self.api.notify_initialize(py_db)
        response = pydevd_base_schema.build_response(request,
                                                     kwargs={'body': body})
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_configurationdone_request(self, py_db, request):
        '''
        :param ConfigurationDoneRequest request:
        '''
        if not self._launch_or_attach_request_done:
            pydev_log.critical(
                'Missing launch request or attach request before configuration done request.'
            )

        self.api.run(py_db)
        self.api.notify_configuration_done(py_db)

        configuration_done_response = pydevd_base_schema.build_response(
            request)
        return NetCommand(CMD_RETURN,
                          0,
                          configuration_done_response,
                          is_json=True)

    def on_threads_request(self, py_db, request):
        '''
        :param ThreadsRequest request:
        '''
        return self.api.list_threads(py_db, request.seq)

    def on_terminate_request(self, py_db, request):
        '''
        :param TerminateRequest request:
        '''
        self._request_terminate_process(py_db)
        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def _request_terminate_process(self, py_db):
        self.api.request_terminate_process(py_db)

    def on_completions_request(self, py_db, request):
        '''
        :param CompletionsRequest request:
        '''
        arguments = request.arguments  # : :type arguments: CompletionsArguments
        seq = request.seq
        text = arguments.text
        frame_id = arguments.frameId
        thread_id = py_db.suspended_frames_manager.get_thread_id_for_variable_reference(
            frame_id)

        if thread_id is None:
            body = CompletionsResponseBody([])
            variables_response = pydevd_base_schema.build_response(
                request,
                kwargs={
                    'body':
                    body,
                    'success':
                    False,
                    'message':
                    'Thread to get completions seems to have resumed already.'
                })
            return NetCommand(CMD_RETURN, 0, variables_response, is_json=True)

        # Note: line and column are 1-based (convert to 0-based for pydevd).
        column = arguments.column - 1

        if arguments.line is None:
            # line is optional
            line = -1
        else:
            line = arguments.line - 1

        self.api.request_completions(py_db,
                                     seq,
                                     thread_id,
                                     frame_id,
                                     text,
                                     line=line,
                                     column=column)

    def _resolve_remote_root(self, local_root, remote_root):
        if remote_root == '.':
            cwd = os.getcwd()
            append_pathsep = local_root.endswith('\\') or local_root.endswith(
                '/')
            return cwd + (os.path.sep if append_pathsep else '')
        return remote_root

    def _set_debug_options(self, py_db, args, start_reason):
        rules = args.get('rules')
        stepping_resumes_all_threads = args.get('steppingResumesAllThreads',
                                                True)
        self.api.set_stepping_resumes_all_threads(
            py_db, stepping_resumes_all_threads)

        terminate_child_processes = args.get('terminateChildProcesses', True)
        self.api.set_terminate_child_processes(py_db,
                                               terminate_child_processes)

        exclude_filters = []

        if rules is not None:
            exclude_filters = _convert_rules_to_exclude_filters(
                rules, self.api.filename_to_server,
                lambda msg: self.api.send_error_message(py_db, msg))

        self.api.set_exclude_filters(py_db, exclude_filters)

        debug_options = _extract_debug_options(
            args.get('options'),
            args.get('debugOptions'),
        )
        self._options.update_fom_debug_options(debug_options)
        self._options.update_from_args(args)

        self.api.set_use_libraries_filter(py_db, self._options.just_my_code)

        path_mappings = []
        for pathMapping in args.get('pathMappings', []):
            localRoot = pathMapping.get('localRoot', '')
            remoteRoot = pathMapping.get('remoteRoot', '')
            remoteRoot = self._resolve_remote_root(localRoot, remoteRoot)
            if (localRoot != '') and (remoteRoot != ''):
                path_mappings.append((localRoot, remoteRoot))

        if bool(path_mappings):
            pydevd_file_utils.setup_client_server_paths(path_mappings)

        if self._options.redirect_output:
            py_db.enable_output_redirection(True, True)
        else:
            py_db.enable_output_redirection(False, False)

        self.api.set_show_return_values(py_db, self._options.show_return_value)

        if not self._options.break_system_exit_zero:
            ignore_system_exit_codes = [0]
            if self._options.django_debug:
                ignore_system_exit_codes += [3]

            self.api.set_ignore_system_exit_codes(py_db,
                                                  ignore_system_exit_codes)

        if self._options.stop_on_entry and start_reason == 'launch':
            self.api.stop_on_entry()

    def _send_process_event(self, py_db, start_method):
        if len(sys.argv) > 0:
            name = sys.argv[0]
        else:
            name = ''

        if isinstance(name, bytes):
            name = name.decode(file_system_encoding, 'replace')
            name = name.encode('utf-8')

        body = ProcessEventBody(
            name=name,
            systemProcessId=os.getpid(),
            isLocalProcess=True,
            startMethod=start_method,
        )
        event = ProcessEvent(body)
        py_db.writer.add_command(
            NetCommand(CMD_PROCESS_EVENT, 0, event, is_json=True))

    def _handle_launch_or_attach_request(self, py_db, request, start_reason):
        self._send_process_event(py_db, start_reason)
        self._launch_or_attach_request_done = True
        self.api.set_enable_thread_notifications(py_db, True)
        self._set_debug_options(py_db,
                                request.arguments.kwargs,
                                start_reason=start_reason)
        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_launch_request(self, py_db, request):
        '''
        :param LaunchRequest request:
        '''
        return self._handle_launch_or_attach_request(py_db,
                                                     request,
                                                     start_reason='launch')

    def on_attach_request(self, py_db, request):
        '''
        :param AttachRequest request:
        '''
        return self._handle_launch_or_attach_request(py_db,
                                                     request,
                                                     start_reason='attach')

    def on_pause_request(self, py_db, request):
        '''
        :param PauseRequest request:
        '''
        arguments = request.arguments  # : :type arguments: PauseArguments
        thread_id = arguments.threadId

        self.api.request_suspend_thread(py_db, thread_id=thread_id)

        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_continue_request(self, py_db, request):
        '''
        :param ContinueRequest request:
        '''
        arguments = request.arguments  # : :type arguments: ContinueArguments
        thread_id = arguments.threadId

        def on_resumed():
            body = {'allThreadsContinued': thread_id == '*'}
            response = pydevd_base_schema.build_response(request,
                                                         kwargs={'body': body})
            cmd = NetCommand(CMD_RETURN, 0, response, is_json=True)
            py_db.writer.add_command(cmd)

        # Only send resumed notification when it has actually resumed!
        # (otherwise the user could send a continue, receive the notification and then
        # request a new pause which would be paused without sending any notification as
        # it didn't really run in the first place).
        py_db.threads_suspended_single_notification.add_on_resumed_callback(
            on_resumed)
        self.api.request_resume_thread(thread_id)

    def on_next_request(self, py_db, request):
        '''
        :param NextRequest request:
        '''
        arguments = request.arguments  # : :type arguments: NextArguments
        thread_id = arguments.threadId

        if py_db.get_use_libraries_filter():
            step_cmd_id = CMD_STEP_OVER_MY_CODE
        else:
            step_cmd_id = CMD_STEP_OVER

        self.api.request_step(py_db, thread_id, step_cmd_id)

        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_stepin_request(self, py_db, request):
        '''
        :param StepInRequest request:
        '''
        arguments = request.arguments  # : :type arguments: StepInArguments
        thread_id = arguments.threadId

        if py_db.get_use_libraries_filter():
            step_cmd_id = CMD_STEP_INTO_MY_CODE
        else:
            step_cmd_id = CMD_STEP_INTO

        self.api.request_step(py_db, thread_id, step_cmd_id)

        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_stepout_request(self, py_db, request):
        '''
        :param StepOutRequest request:
        '''
        arguments = request.arguments  # : :type arguments: StepOutArguments
        thread_id = arguments.threadId

        if py_db.get_use_libraries_filter():
            step_cmd_id = CMD_STEP_RETURN_MY_CODE
        else:
            step_cmd_id = CMD_STEP_RETURN

        self.api.request_step(py_db, thread_id, step_cmd_id)

        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def _get_hit_condition_expression(self, hit_condition):
        '''Following hit condition values are supported

        * x or == x when breakpoint is hit x times
        * >= x when breakpoint is hit more than or equal to x times
        * % x when breakpoint is hit multiple of x times

        Returns '@HIT@ == x' where @HIT@ will be replaced by number of hits
        '''
        if not hit_condition:
            return None

        expr = hit_condition.strip()
        try:
            int(expr)
            return '@HIT@ == {}'.format(expr)
        except ValueError:
            pass

        if expr.startswith('%'):
            return '@HIT@ {} == 0'.format(expr)

        if expr.startswith('==') or \
            expr.startswith('>') or \
            expr.startswith('<'):
            return '@HIT@ {}'.format(expr)

        return hit_condition

    def on_disconnect_request(self, py_db, request):
        '''
        :param DisconnectRequest request:
        '''
        if request.arguments.terminateDebuggee:
            self._request_terminate_process(py_db)
            response = pydevd_base_schema.build_response(request)
            return NetCommand(CMD_RETURN, 0, response, is_json=True)

        self._launch_or_attach_request_done = False
        py_db.enable_output_redirection(False, False)
        self.api.request_disconnect(py_db, resume_threads=True)

        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_setbreakpoints_request(self, py_db, request):
        '''
        :param SetBreakpointsRequest request:
        '''
        if not self._launch_or_attach_request_done:
            # Note that to validate the breakpoints we need the launch request to be done already
            # (otherwise the filters wouldn't be set for the breakpoint validation).
            body = SetBreakpointsResponseBody([])
            response = pydevd_base_schema.build_response(
                request,
                kwargs={
                    'body':
                    body,
                    'success':
                    False,
                    'message':
                    'Breakpoints may only be set after the launch request is received.'
                })
            return NetCommand(CMD_RETURN, 0, response, is_json=True)

        arguments = request.arguments  # : :type arguments: SetBreakpointsArguments
        # TODO: Path is optional here it could be source reference.
        filename = self.api.filename_to_str(arguments.source.path)
        func_name = 'None'

        self.api.remove_all_breakpoints(py_db, filename)

        btype = 'python-line'
        suspend_policy = 'ALL'

        if not filename.lower().endswith(
                '.py'):  # Note: check based on original file, not mapping.
            if self._options.django_debug:
                btype = 'django-line'
            elif self._options.flask_debug:
                btype = 'jinja2-line'

        breakpoints_set = []

        for source_breakpoint in arguments.breakpoints:
            source_breakpoint = SourceBreakpoint(**source_breakpoint)
            line = source_breakpoint.line
            condition = source_breakpoint.condition
            breakpoint_id = line

            hit_condition = self._get_hit_condition_expression(
                source_breakpoint.hitCondition)
            log_message = source_breakpoint.logMessage
            if not log_message:
                is_logpoint = None
                expression = None
            else:
                is_logpoint = True
                expression = convert_dap_log_message_to_expression(log_message)

            result = self.api.add_breakpoint(py_db,
                                             filename,
                                             btype,
                                             breakpoint_id,
                                             line,
                                             condition,
                                             func_name,
                                             expression,
                                             suspend_policy,
                                             hit_condition,
                                             is_logpoint,
                                             adjust_line=True)
            error_code = result.error_code

            if error_code:
                if error_code == self.api.ADD_BREAKPOINT_FILE_NOT_FOUND:
                    error_msg = 'Breakpoint in file that does not exist.'

                elif error_code == self.api.ADD_BREAKPOINT_FILE_EXCLUDED_BY_FILTERS:
                    error_msg = 'Breakpoint in file excluded by filters.'
                    if py_db.get_use_libraries_filter():
                        error_msg += (
                            '\nNote: may be excluded because of "justMyCode" option (default == true).'
                            'Try setting \"justMyCode\": false in the debug configuration (e.g., launch.json).\n'
                        )

                else:
                    # Shouldn't get here.
                    error_msg = 'Breakpoint not validated (reason unknown -- please report as bug).'

                breakpoints_set.append(
                    pydevd_schema.Breakpoint(
                        verified=False,
                        line=result.translated_line,
                        message=error_msg,
                        source=arguments.source).to_dict())
            else:
                # Note that the id is made up (the id for pydevd is unique only within a file, so, the
                # line is used for it).
                # Also, the id is currently not used afterwards, so, we don't even keep a mapping.
                breakpoints_set.append(
                    pydevd_schema.Breakpoint(
                        verified=True,
                        id=self._next_breakpoint_id(),
                        line=result.translated_line,
                        source=arguments.source).to_dict())

        body = {'breakpoints': breakpoints_set}
        set_breakpoints_response = pydevd_base_schema.build_response(
            request, kwargs={'body': body})
        return NetCommand(CMD_RETURN,
                          0,
                          set_breakpoints_response,
                          is_json=True)

    def on_setexceptionbreakpoints_request(self, py_db, request):
        '''
        :param SetExceptionBreakpointsRequest request:
        '''
        # : :type arguments: SetExceptionBreakpointsArguments
        arguments = request.arguments
        filters = arguments.filters
        exception_options = arguments.exceptionOptions
        self.api.remove_all_exception_breakpoints(py_db)

        # Can't set these in the DAP.
        condition = None
        expression = None
        notify_on_first_raise_only = False

        ignore_libraries = 1 if py_db.get_use_libraries_filter() else 0

        if exception_options:
            break_raised = True
            break_uncaught = True

            for option in exception_options:
                option = ExceptionOptions(**option)
                if not option.path:
                    continue

                notify_on_handled_exceptions = 1 if option.breakMode == 'always' else 0
                notify_on_unhandled_exceptions = 1 if option.breakMode in (
                    'unhandled', 'userUnhandled') else 0
                exception_paths = option.path

                exception_names = []
                if len(exception_paths) == 0:
                    continue

                elif len(exception_paths) == 1:
                    if 'Python Exceptions' in exception_paths[0]['names']:
                        exception_names = ['BaseException']

                else:
                    path_iterator = iter(exception_paths)
                    if 'Python Exceptions' in next(path_iterator)['names']:
                        for path in path_iterator:
                            for ex_name in path['names']:
                                exception_names.append(ex_name)

                for exception_name in exception_names:
                    self.api.add_python_exception_breakpoint(
                        py_db, exception_name, condition, expression,
                        notify_on_handled_exceptions,
                        notify_on_unhandled_exceptions,
                        notify_on_first_raise_only, ignore_libraries)

        else:
            break_raised = 'raised' in filters
            break_uncaught = 'uncaught' in filters
            if break_raised or break_uncaught:
                notify_on_handled_exceptions = 1 if break_raised else 0
                notify_on_unhandled_exceptions = 1 if break_uncaught else 0
                exception = 'BaseException'

                self.api.add_python_exception_breakpoint(
                    py_db, exception, condition, expression,
                    notify_on_handled_exceptions,
                    notify_on_unhandled_exceptions, notify_on_first_raise_only,
                    ignore_libraries)

        if break_raised or break_uncaught:
            btype = None
            if self._options.django_debug:
                btype = 'django'
            elif self._options.flask_debug:
                btype = 'jinja2'

            if btype:
                self.api.add_plugins_exception_breakpoint(
                    py_db, btype, 'BaseException'
                )  # Note: Exception name could be anything here.

        # Note: no body required on success.
        set_breakpoints_response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN,
                          0,
                          set_breakpoints_response,
                          is_json=True)

    def on_stacktrace_request(self, py_db, request):
        '''
        :param StackTraceRequest request:
        '''
        # : :type stack_trace_arguments: StackTraceArguments
        stack_trace_arguments = request.arguments
        thread_id = stack_trace_arguments.threadId
        start_frame = stack_trace_arguments.startFrame
        levels = stack_trace_arguments.levels

        fmt = stack_trace_arguments.format
        if hasattr(fmt, 'to_dict'):
            fmt = fmt.to_dict()
        self.api.request_stack(py_db,
                               request.seq,
                               thread_id,
                               fmt=fmt,
                               start_frame=start_frame,
                               levels=levels)

    def on_exceptioninfo_request(self, py_db, request):
        '''
        :param ExceptionInfoRequest request:
        '''
        # : :type exception_into_arguments: ExceptionInfoArguments
        exception_into_arguments = request.arguments
        thread_id = exception_into_arguments.threadId
        max_frames = self._options.max_exception_stack_frames
        self.api.request_exception_info_json(py_db, request, thread_id,
                                             max_frames)

    def on_scopes_request(self, py_db, request):
        '''
        Scopes are the top-level items which appear for a frame (so, we receive the frame id
        and provide the scopes it has).

        :param ScopesRequest request:
        '''
        frame_id = request.arguments.frameId

        variables_reference = frame_id
        scopes = [Scope('Locals', int(variables_reference), False).to_dict()]
        body = ScopesResponseBody(scopes)
        scopes_response = pydevd_base_schema.build_response(
            request, kwargs={'body': body})
        return NetCommand(CMD_RETURN, 0, scopes_response, is_json=True)

    def on_evaluate_request(self, py_db, request):
        '''
        :param EvaluateRequest request:
        '''
        # : :type arguments: EvaluateArguments
        arguments = request.arguments

        if arguments.frameId is None:
            self.api.request_exec_or_evaluate_json(py_db,
                                                   request,
                                                   thread_id='*')
        else:
            thread_id = py_db.suspended_frames_manager.get_thread_id_for_variable_reference(
                arguments.frameId)

            if thread_id is not None:
                self.api.request_exec_or_evaluate_json(py_db, request,
                                                       thread_id)
            else:
                body = EvaluateResponseBody('', 0)
                response = pydevd_base_schema.build_response(
                    request,
                    kwargs={
                        'body': body,
                        'success': False,
                        'message': 'Unable to find thread for evaluation.'
                    })
                return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_setexpression_request(self, py_db, request):
        # : :type arguments: SetExpressionArguments
        arguments = request.arguments

        thread_id = py_db.suspended_frames_manager.get_thread_id_for_variable_reference(
            arguments.frameId)

        if thread_id is not None:
            self.api.request_set_expression_json(py_db, request, thread_id)
        else:
            body = SetExpressionResponseBody('')
            response = pydevd_base_schema.build_response(
                request,
                kwargs={
                    'body': body,
                    'success': False,
                    'message': 'Unable to find thread to set expression.'
                })
            return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_variables_request(self, py_db, request):
        '''
        Variables can be asked whenever some place returned a variables reference (so, it
        can be a scope gotten from on_scopes_request, the result of some evaluation, etc.).

        Note that in the DAP the variables reference requires a unique int... the way this works for
        pydevd is that an instance is generated for that specific variable reference and we use its
        id(instance) to identify it to make sure all items are unique (and the actual {id->instance}
        is added to a dict which is only valid while the thread is suspended and later cleared when
        the related thread resumes execution).

        see: SuspendedFramesManager

        :param VariablesRequest request:
        '''
        arguments = request.arguments  # : :type arguments: VariablesArguments
        variables_reference = arguments.variablesReference

        thread_id = py_db.suspended_frames_manager.get_thread_id_for_variable_reference(
            variables_reference)
        if thread_id is not None:
            self.api.request_get_variable_json(py_db, request, thread_id)
        else:
            variables = []
            body = VariablesResponseBody(variables)
            variables_response = pydevd_base_schema.build_response(
                request,
                kwargs={
                    'body':
                    body,
                    'success':
                    False,
                    'message':
                    'Unable to find thread to evaluate variable reference.'
                })
            return NetCommand(CMD_RETURN, 0, variables_response, is_json=True)

    def on_setvariable_request(self, py_db, request):
        arguments = request.arguments  # : :type arguments: SetVariableArguments
        variables_reference = arguments.variablesReference

        if arguments.name.startswith('(return) '):
            response = pydevd_base_schema.build_response(
                request,
                kwargs={
                    'body': SetVariableResponseBody(''),
                    'success': False,
                    'message': 'Cannot change return value'
                })
            return NetCommand(CMD_RETURN, 0, response, is_json=True)

        thread_id = py_db.suspended_frames_manager.get_thread_id_for_variable_reference(
            variables_reference)

        if thread_id is not None:
            self.api.request_change_variable_json(py_db, request, thread_id)
        else:
            response = pydevd_base_schema.build_response(
                request,
                kwargs={
                    'body':
                    SetVariableResponseBody(''),
                    'success':
                    False,
                    'message':
                    'Unable to find thread to evaluate variable reference.'
                })
            return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_modules_request(self, py_db, request):
        modules_manager = py_db.cmd_factory.modules_manager  # : :type modules_manager: ModulesManager
        modules_info = modules_manager.get_modules_info()
        body = ModulesResponseBody(modules_info)
        variables_response = pydevd_base_schema.build_response(
            request, kwargs={'body': body})
        return NetCommand(CMD_RETURN, 0, variables_response, is_json=True)

    def on_source_request(self, py_db, request):
        '''
        :param SourceRequest request:
        '''
        source_reference = request.arguments.sourceReference
        server_filename = None
        content = None

        if source_reference != 0:
            server_filename = pydevd_file_utils.get_server_filename_from_source_reference(
                source_reference)
            if server_filename:
                # Try direct file access first - it's much faster when available.
                try:
                    with open(server_filename, 'r') as stream:
                        content = stream.read()
                except:
                    pass

                if content is None:
                    # File might not exist at all, or we might not have a permission to read it,
                    # but it might also be inside a zipfile, or an IPython cell. In this case,
                    # linecache might still be able to retrieve the source.
                    lines = (linecache.getline(server_filename, i)
                             for i in itertools.count(1))
                    lines = itertools.takewhile(
                        bool, lines)  # empty lines are '\n', EOF is ''

                    # If we didn't get at least one line back, reset it to None so that it's
                    # reported as error below, and not as an empty file.
                    content = ''.join(lines) or None

        body = SourceResponseBody(content or '')
        response_args = {'body': body}

        if content is None:
            if source_reference == 0:
                message = 'Source unavailable'
            elif server_filename:
                message = 'Unable to retrieve source for %s' % (
                    server_filename, )
            else:
                message = 'Invalid sourceReference %d' % (source_reference, )
            response_args.update({'success': False, 'message': message})

        response = pydevd_base_schema.build_response(request,
                                                     kwargs=response_args)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_gototargets_request(self, py_db, request):
        path = request.arguments.source.path
        line = request.arguments.line
        target_id = self._goto_targets_map.obtain_key((path, line))
        target = {
            'id': target_id,
            'label': '%s:%s' % (path, line),
            'line': line
        }
        body = GotoTargetsResponseBody(targets=[target])
        response_args = {'body': body}
        response = pydevd_base_schema.build_response(request,
                                                     kwargs=response_args)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_goto_request(self, py_db, request):
        target_id = int(request.arguments.targetId)
        thread_id = request.arguments.threadId
        try:
            _, line = self._goto_targets_map.obtain_value(target_id)
        except KeyError:
            response = pydevd_base_schema.build_response(
                request,
                kwargs={
                    'body': {},
                    'success': False,
                    'message': 'Unknown goto target id: %d' % (target_id, ),
                })
            return NetCommand(CMD_RETURN, 0, response, is_json=True)

        self.api.request_set_next(py_db, request.seq, thread_id,
                                  CMD_SET_NEXT_STATEMENT, line, '*')
        # See 'NetCommandFactoryJson.make_set_next_stmnt_status_message' for response
        return None

    def on_setdebuggerproperty_request(self, py_db, request):
        args = request.arguments  # : :type args: SetDebuggerPropertyArguments
        if args.ideOS is not None:
            self.api.set_ide_os(args.ideOS)

        if args.dontTraceStartPatterns is not None and args.dontTraceEndPatterns is not None:
            start_patterns = tuple(args.dontTraceStartPatterns)
            end_patterns = tuple(args.dontTraceEndPatterns)
            self.api.set_dont_trace_start_end_patterns(py_db, start_patterns,
                                                       end_patterns)

        if args.skipSuspendOnBreakpointException is not None:
            py_db.skip_suspend_on_breakpoint_exception = tuple(
                get_exception_class(x)
                for x in args.skipSuspendOnBreakpointException)

        if args.skipPrintBreakpointException is not None:
            py_db.skip_print_breakpoint_exception = tuple(
                get_exception_class(x)
                for x in args.skipPrintBreakpointException)

        if args.multiThreadsSingleNotification is not None:
            py_db.multi_threads_single_notification = args.multiThreadsSingleNotification

        # TODO: Support other common settings. Note that not all of these might be relevant to python.
        # JustMyCodeStepping: 0 or 1
        # AllowOutOfProcessSymbols: 0 or 1
        # DisableJITOptimization: 0 or 1
        # InterpreterOptions: 0 or 1
        # StopOnExceptionCrossingManagedBoundary: 0 or 1
        # WarnIfNoUserCodeOnLaunch: 0 or 1
        # EnableStepFiltering: true of false

        response = pydevd_base_schema.build_response(request,
                                                     kwargs={'body': {}})
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_pydevdsysteminfo_request(self, py_db, request):
        try:
            pid = os.getpid()
        except AttributeError:
            pid = None

        # It's possible to have the ppid reported from args. In this case, use that instead of the
        # real ppid (athough we're using `ppid`, what we want in meaning is the `launcher_pid` --
        # so, if a python process is launched from another python process, consider that process the
        # parent and not any intermediary stubs).

        ppid = py_db.get_arg_ppid() or self.api.get_ppid()

        try:
            impl_desc = platform.python_implementation()
        except AttributeError:
            impl_desc = PY_IMPL_NAME

        py_info = pydevd_schema.PydevdPythonInfo(
            version=PY_VERSION_STR,
            implementation=pydevd_schema.PydevdPythonImplementationInfo(
                name=PY_IMPL_NAME,
                version=PY_IMPL_VERSION_STR,
                description=impl_desc,
            ))
        platform_info = pydevd_schema.PydevdPlatformInfo(name=sys.platform)
        process_info = pydevd_schema.PydevdProcessInfo(
            pid=pid,
            ppid=ppid,
            executable=sys.executable,
            bitness=64 if IS_64BIT_PROCESS else 32,
        )
        pydevd_info = pydevd_schema.PydevdInfo(
            usingCython=USING_CYTHON,
            usingFrameEval=USING_FRAME_EVAL,
        )
        body = {
            'python': py_info,
            'platform': platform_info,
            'process': process_info,
            'pydevd': pydevd_info,
        }
        response = pydevd_base_schema.build_response(request,
                                                     kwargs={'body': body})
        return NetCommand(CMD_RETURN, 0, response, is_json=True)

    def on_setpydevdsourcemap_request(self, py_db, request):
        args = request.arguments  # : :type args: SetPydevdSourceMapArguments
        SourceMappingEntry = self.api.SourceMappingEntry

        path = args.source.path
        source_maps = args.pydevdSourceMaps
        # : :type source_map: PydevdSourceMap
        new_mappings = [
            SourceMappingEntry(
                source_map['line'], source_map['endLine'],
                source_map['runtimeLine'],
                self.api.filename_to_str(source_map['runtimeSource']['path']))
            for source_map in source_maps
        ]

        error_msg = self.api.set_source_mapping(py_db, path, new_mappings)
        if error_msg:
            response = pydevd_base_schema.build_response(request,
                                                         kwargs={
                                                             'body': {},
                                                             'success': False,
                                                             'message':
                                                             error_msg,
                                                         })
            return NetCommand(CMD_RETURN, 0, response, is_json=True)

        response = pydevd_base_schema.build_response(request)
        return NetCommand(CMD_RETURN, 0, response, is_json=True)