tree 8107810ed70adee1aac0267581f731d8ab10131f
parent 1ff1de24c696a99868b3dffea8cf65f768e24b37
author Edwin Kempin <ekempin@google.com> 1627035001 +0200
committer Edwin Kempin <ekempin@google.com> 1627285742 +0200

RestApiServlet: Handle RequestCancelledException for REST calls

Catch RequestCancelledException in RestApiServlet and return proper
HTTP response codes.

RequestCancelledException is not being thrown yet, this is a preparation
to handle it correctly when we start detecting cancelled requests later
and aborting them by throwing this exception.

If a request is cancelled we return '499 Client Closed Request'. This is
a non-standard status code that was introduced by nginx for the case
when a client closes the connection [1].

If a request is cancelled due to an exceeded deadline we return '408
Client Provided Deadline Exceeded' or '408 Server Deadline Exceeded'.
408 is a standard response code that is returned when a request timed
out [2].

[1] https://httpstatuses.com/499
[2] https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/408

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: Ice6d35a04c68e850307fc36d0ef71c5d3a15ecb9