[Qt-interest] QAbstractFileEngine problems

[Eric Landuyt]

Hello Jason,

Thursday, July 8, 2010, 4:45:49 PM, you wrote:
JH> Thanks everyone! I got my stuff to work, only to find out that I can't use it.
JH> SQLite's BLOB handling is horrible. It has to load the entire thing into memory,
JH> which just won't work for me. (I also found that BLOBS cannot be incrementally
JH> appended to or read, which is an essential feature of write() an read()!)

SQLite offers an incremental IO API for blobs, which seems to be designed
especially for such cases:
http://www.sqlite.org/capi3ref.html#sqlite3_blob_bytes
I never played with it though, and you will not be able to directly use this
from QtSql (you can only obtain a sqlite3* handle through driver()->handle() ).

JH> //out.fileEngine()->setMetadata(map); // I want to do this

Did you try to compile this line ? ;) In fact I discovered some time ago that
there is exactly a public fileEngine() method in qfile.h , but this one is not
documented anywhere. Moreover, there is no equivalent public method available
in QDir ...

--
Eric Landuyt, Developer - mailto:eric at datarescue.be
DataRescue sa/nv - http://www.datarescue.com