Huge Tools performances decrease since the compression lib changes

Hi,

We used to work with QT IFW 4.1.1 and recentrly made a switch to 4.3.0

We only use regular IFW Build provided by Qt.

Fact is that the tools used for compression (repogen / binarycreator) sees a huge performance hit in the last version on windows.

I've made some tests, and here's the results :

On a build machine, the process initially took about 431 seconds.

Now it took about {{1780}}seconds ....

On my dev desktop, I've seen the following numbers, for about 2.24 Go of datas :

4.1.1 : 3 minutes, resulting installer of 353,619 Ko

4.3.0 : 12 minuts, resulting installer of 452,547 Ko

So it takes 4 more times to compress 28% less. Quite degrading.