[OpenSIPS-Devel] [OpenSIPS/opensips] f46afc: rest_client: Disable "Expect: 100-continue" by def...

[Liviu Chircu]

  Branch: refs/heads/2.4
  Home:   https://github.com/OpenSIPS/opensips
  Commit: f46afc50a7247052cbb5255a15fdb888a8979049
      https://github.com/OpenSIPS/opensips/commit/f46afc50a7247052cbb5255a15fdb888a8979049
  Author: Liviu Chircu <liviu at opensips.org>
  Date:   2020-04-22 (Wed, 22 Apr 2020)

  Changed paths:
    M modules/rest_client/doc/rest_client_admin.xml
    M modules/rest_client/rest_client.c
    M modules/rest_client/rest_methods.c

  Log Message:
  -----------
  rest_client: Disable "Expect: 100-continue" by default

Although the "100 Continue" flow sometimes saves bandwidth when the
server replies with an error response, it also has some drawbacks:

    * extra roundtrips, adding latency and complicating the async
        handling
    * the client body upload and server body download must be performed
        within the same curl_multi_perform() loop, during the async
        resume callback, limiting the amount of parallelism that can be
        obtained when compared to the simple flow

>From now on, the "100 Continue" flow for POST/PUT requests with bodies
larger than 1024 bytes is disabled by default.  Developers may enable it
using a new, backwards-compatible, "enable_expect_100" module parameter.

Fixes #2081