Pickleable AuthorizedSession

[golddranks]

Is your feature request related to a problem? Please describe. In our Django application, to access some Google API's as a part of the processing for some requests, we are currently creating a AuthorizedSession per request where it's needed. However, this tends to take some time, from 0.5 seconds to 1.0 second. In some cases, we are getting bursts of 5-10 subsequent requests, and the time of authorizing sessions might delay the user getting the end result by multiple seconds. We'd like to cache AuthorizedSession, and it would be enough to cache it in Django's LocMemCache, but this requires the cached object to be pickleable, so we are currently unable to do that.

Describe the solution you'd like Make AuthorizedSession pickleable, so the caches would work. Currently many of the _ attributes get lost. Here is a comparision of dir() before and after pickling:

 ['__attrs__', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_auth_request', '_auth_request_session', '_default_host', '_is_mtls', '_max_refresh_attempts', '_refresh_status_codes', '_refresh_timeout', 'adapters', 'auth', 'cert', 'close', 'configure_mtls_channel', 'cookies', 'credentials', 'delete', 'get', 'get_adapter', 'get_redirect_target', 'head', 'headers', 'hooks', 'is_mtls', 'max_redirects', 'merge_environment_settings', 'mount', 'options', 'params', 'patch', 'post', 'prepare_request', 'proxies', 'put', 'rebuild_auth', 'rebuild_method', 'rebuild_proxies', 'request', 'resolve_redirects', 'send', 'should_strip_auth', 'stream', 'trust_env', 'verify']

vs.

['__attrs__', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'adapters', 'auth', 'cert', 'close', 'configure_mtls_channel', 'cookies', 'delete', 'get', 'get_adapter', 'get_redirect_target', 'head', 'headers', 'hooks', 'is_mtls', 'max_redirects', 'merge_environment_settings', 'mount', 'options', 'params', 'patch', 'post', 'prepare_request', 'proxies', 'put', 'rebuild_auth', 'rebuild_method', 'rebuild_proxies', 'request', 'resolve_redirects', 'send', 'should_strip_auth', 'stream', 'trust_env', 'verify']

The difference seems to be:

'_auth_request', '_auth_request_session', '_default_host', '_is_mtls', '_max_refresh_attempts', '_refresh_status_codes', '_refresh_timeout', 'credentials'

And indeed, the error when trying with cache, is about missing _auth_request.

Describe alternatives you've considered

• Asking to make AuthorizedSession thread-safe, so we could just stick it into a singleton object. This seems to be hard, because the underlying Requests isn't apparently thread-safe.
• Using some kind of object pool, which would allow using AuthorizedSession as is. This would bring some unrelated complexity from the framework and utility libraries, to the application side, so it doesn't feel quite right to do as the first go-to option.

[clundin25]

Asking to make AuthorizedSession thread-safe, so we could just stick it into a singleton object. This seems to be hard, because the underlying Requests isn't apparently thread-safe.

Is wrapping the AuthorizedSession with a mutex an option?

I am not keen on making AuthorizedSession pickle-able but I have not done a thorough investigation.

[clundin25]

We chatted about this and we don't believe we will support pickling AuthorizedSessions. Please re-open this if you have any more questions!