[Bug 31438] [EA Origin]Unable to download game since the new version

[wine-bugs at winehq.org]

http://bugs.winehq.org/show_bug.cgi?id=31438

--- Comment #122 from Heiko <lil_tux at web.de> ---
(In reply to Alessandro Pignotti from comment #121)
> I agree the docs says that TcpSockets should always be buffered, but this
> does not seem to be true. They definitely are buffered by default, but for
> HTTP connection the mode is changed in
> QHttpNetworkConnectionChannel::ensureConnection. You can see that when the
> connection is not SSL based it will pass the QIODevice::Unbuffered flag to
> the connectToHost call.
> 

Damn, I should've seen that. Thanks for your insights and hinting. That 'new'
feature of Qt. There's even a statement...
"
    // Before Qt 4.6, we always set the send and receive buffer size to 49152
as
    // this was found to be an optimal value. However, modern OS
    // all have some kind of auto tuning for this and we therefore don't set
    // this explictly anymore.
    // If it introduces any performance regressions for Qt 4.6.x (x > 0) then
    // it will be put back in.
    //
    // You can use tests/manual/qhttpnetworkconnection to test HTTP download
speed
    // with this.
    //
    // pre-4.6:
    // setReceiveBufferSize(49152);
    // setSendBufferSize(49152);
"

Ok, your words are awesomely correct. Sorry for not believing at first. For now
I've got another workaround: patch Qt5Network.dll
Basically you just need to change byte 518626 from 0 to 1. That makes the
QTcpSocket buffered again. Download speed went to 1,6MB/s.

>> cmp -bl Qt5Network.dll.orig Qt5Network.dll.patched
518626   0 ^@     1 ^A

Still does feel wrong to me to repeatedly pull 1 byte from the socket (and to
write QTcpSocket is always buffered into the doc).

So, kudos to Alessandro for really figuring the cause. Thanks!

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