[Development] Mime database size

Kevin Kofler kevin.kofler at chello.at
Thu Feb 19 01:55:01 CET 2015

Arnaud Vrac wrote:
> Commit fbeeaf2 in qtbase adds QT_NO_MIMETYPE:
> "The mime type stuff generates one of the biggest translation units in
> QtCore due to the compressed 1.7MB freedesktop.org.xml resource. With
> QT_NO_MIMETYPE, libQt5Core.so is almost 400Kb smaller (4.8MB->4.4MB gcc
> 4.9 stripped release build)"
> It would be nice to be able to find a middle ground between disabling the
> mime database completely and adding 1.7MB of data to Qt. The
> update-mime-database binary from the shared-mime-info package can generate
> a binary file from the XML, which is 100KB large and still allows finding
> the mimetype of any file. The only difference with the XML is that you
> don't have the translated pretty string for the mime type. The binary file
> can also be mmapped and used for every request very efficiently, instead
> of allocating all mime types data in memory.

This won't help the other platforms, but on GNU/Linux, can't we just use the 
system shared-mime-info database?

        Kevin Kofler

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