Source code for hbp_nrp_backend.rest_server.RestSyncMiddleware

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# This file is part of the Neurorobotics Platform software
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"""
This module makes some rest requests multi-threadable.
By default, all rest requests are considered not thread safe and are therefore synchronized.
Requests that are known to be thread-safe, are executed concurrently.
To mark a rest request as thread-safe, decorate the Resource function handling the request
(get, post, delete, put) with the decorator @RestSyncMiddleware.threadsafe
"""
from builtins import object
from threading import Lock
import logging

logger = logging.getLogger(__name__)


[docs]class RestSyncMiddleware(object): """ Middleware that allows thread-safe requests to be executed concurrently """ def __init__(self, wsgi_app, app): self.wsgi_app = wsgi_app self.app = app self.threadLock = Lock()
[docs] @staticmethod def threadsafe(func): """ Decorates functions as thread-safe """ func.is_threadsafe = True return func
def __call__(self, environ, start_response): pathinfo = environ.get("PATH_INFO") method = environ.get("REQUEST_METHOD") viewfunction, _ = self.app.url_map.bind( 'localhost', default_method=method).match(pathinfo) viewclass = self.app.view_functions[viewfunction].view_class viewfn = getattr(viewclass, method.lower()) if not hasattr(viewfn, "is_threadsafe"): self.threadLock.acquire() try: res = self.wsgi_app(environ, start_response) # pylint: disable=broad-except except Exception as e: logger.exception(e) res = None finally: if not hasattr(viewfn, "is_threadsafe"): self.threadLock.release() return res