HTTP/2 protocol handler: tweak receive window sizes

We were using the default ones, provided by RFC7540. It appears they are way
too restrictive and conservative: when downloading something relatively big,
a stream keeps spending the whole session/its own 'recv' windows and thus
we have to constantly send WINDOW_UPDATE frames. This significantly slows
down our HTTP/2 implementation, making it orders of magnitude slower than
HTTP/1.1. To fix this:

- We send SETTINGS_INITIAL_WINDOW_SIZE in the first SETTINGS frame
  to inform our peer that per-stream WINDOW is bigger than 64Kb
- We increase the session's receive window size.

Task-number: QTBUG-63722
Change-Id: I31312fcfd5f0fc0aee6aaa5d3562cc7d1b931adc
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

0 files changed, 0 insertions, 0 deletions