commit e4399c510f0e96fa2881a2fa45ade05b24ec5056
author Edwin Kempin <ekempin@google.com> Mon Dec 23 11:41:58 2019 +0100
committer Edwin Kempin <ekempin@google.com> Thu Jan 09 09:58:15 2020 +0100
tree 05578e4752ecc4a45357eddb9c6beca2812fccec
parent 7cac69f2da281364685d5b37f649e454d0ff1696

Record correct status in REST metric if ExceptionHook changed the status

The http/server/rest_api/error_count metric counts the number of error
responses (status code >= 400). The status code is provided as metric
field so that you can see the error count by status code. If an
exception occurred we always counted it as 500 ISE for the metric, even
if an ExceptionHook changed the status code to something else. This was
because changing the status code due to ExceptionHook was done in the
handleException method, but the caller of this method (service method)
didn't get informed about the change of the status code, hence it still
recorded a 500 ISE for the metric.

The handleException method used its return value to return the number of
bytes that have been written to the response, hence we can't return the
new status code from this method easily. To fix the issue the
handleException method was first inlined so that all handling of the
status code is inside the service method, then code blocks were factored
out into new methods so that the service method doesn't grow too big.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I0faffdd19d50cf54be70257352880dc6f7788146