Details
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Bug
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Resolution: Done
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P2: Important
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4.8.4, 5.0.0 Beta 2
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BlackBerry 10 10.0.9 beta3
Description
I noticed a very poor performance of http downloads in my application. During my investigations I found that disabling I/O buffering fixes this problem.
Internally Qt uses fopen() for buffered I/O and open() for unbuffered (see openModeToFopenMode() in qfsfileengine_unix.cpp). BlackBerry/QNX documentation [1] suggests to prevent usage of fopen() for file I/O because of FS buffering.
I have attached a small test application for BlackBerry 10. Everyone can see a difference between buffered and unbuffered I/O by a simple change of QFile::open() parameters in downloadmanager.cpp:27.
Attachments
For Gerrit Dashboard: QTBUG-28252 | ||||||
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# | Subject | Branch | Project | Status | CR | V |
41062,3 | blackberry: do not use buffered fs I/O | master | qt/qtbase | Status: ABANDONED | -2 | 0 |