Currently we use `JsonEncoder.iterencode` to write JSON responses, which ensures that we don't block the main reactor thread when encoding huge objects. The downside to this is that `iterencode` falls back to using a pure Python encoder that is *much* less efficient and can easily burn a lot of CPU for huge responses. To fix this, while still ensuring we don't block the reactor loop, we encode the JSON on a threadpool using the standard `JsonEncoder.encode` functions, which is backed by a C library.
Doing so, however, requires `respond_with_json` to have access to the reactor, which it previously didn't. There are two ways of doing this:
1. threading through the reactor object, which is a bit fiddly as e.g. `DirectServeJsonResource` doesn't currently take a reactor, but is exposed to modules and so is a PITA to change; or
2. expose the reactor in `SynapseRequest`, which requires updating a bunch of servlet types.
I went with the latter as that is just a mechanical change, and I think makes sense as a request already has a reactor associated with it (via its http channel).
* Drop Origin & Accept from Access-Control-Allow-Headers value
This change drops the Origin and Accept header names from the value of the
Access-Control-Allow-Headers response header sent by Synapse. Per the CORS
protocol, it’s not necessary or useful to include those header names.
Details:
Per-spec at https://fetch.spec.whatwg.org/#forbidden-header-name, Origin
is a “forbidden header name” set by the browser and that frontend
JavaScript code is never allowed to set.
So the value of Access-Control-Allow-Headers isn’t relevant to Origin or
in general to other headers set by the browser itself — the browser
never ever consults the Access-Control-Allow-Headers value to confirm
that it’s OK for the request to include an Origin header.
And per-spec at https://fetch.spec.whatwg.org/#cors-safelisted-request-header,
Accept is a “CORS-safelisted request-header”, which means that browsers
allow requests to contain the Accept header regardless of whether the
Access-Control-Allow-Headers value contains "Accept".
So it’s unnecessary for the Access-Control-Allow-Headers to explicitly
include Accept. Browsers will not perform a CORS preflight for requests
containing an Accept request header.
Related: https://github.com/matrix-org/matrix-doc/pull/3225
Signed-off-by: Michael[tm] Smith <mike@w3.org>
Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
- Update black version to the latest
- Run black auto formatting over the codebase
- Run autoformatting according to [`docs/code_style.md
`](80d6dc9783/docs/code_style.md)
- Update `code_style.md` docs around installing black to use the correct version
There are going to be a couple of paths to get to the final step of SSO reg, and I want the URL in the browser to consistent. So, let's move the final step onto a separate path, which we redirect to.
Not being able to serialise `frozendicts` is fragile, and it's annoying to have
to think about which serialiser you want. There's no real downside to
supporting frozendicts, so let's just have one json encoder.
* Expose `return_html_error`, and allow it to take a Jinja2 template instead of a raw string
* Clean up exception handling in SAML2ResponseResource
* use the existing code in `return_html_error` instead of re-implementing it
(giving it a jinja2 template rather than inventing a new form of template)
* do the exception-catching in the REST layer rather than in the handler
layer, to make sure we catch all exceptions.
* Fix servlet metric names
Co-Authored-By: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
* Remove redundant check
* Cover all return paths
Firstly, we always logged that the request was being handled via
`JsonResource._async_render`, so we change that to use the servlet name
we add to the request.
Secondly, we pass the exception information to the logger rather than
formatting it manually. This makes it consistent with other exception
logging, allwoing logging hooks and formatters to access the exception
information.
If a HTTP handler throws an exception while processing a request we
automatically write a JSON error response. If the handler had already
started writing a response twisted throws an exception.
We should check for this case and simple abort the connection if there
was an error after the response had started being written.
The problem with dumping all of the json response into the Request object at
once is that doing so starts the timeout for the next request to be received:
so if it takes longer than 60s to stream back the response to the client, the
client never gets it.
The correct solution is to use a Producer; then the timeout is only started
once all of the content is sent over the TCP connection.
Erik Johnston