further I/O optimizations may be made via posix_fadvise() and maybe
by getting rid of the write buffer management in QFile and letting
the OS deal with buffering. more research, tests, etc. will have
to be made ofcourse.
on a side note, https://www.gnu.org/software/libc/manual/html_node/Operating-Modes.html
mentions that O_SYNC is another name for O_FSYNC which is a BSD feature
but is currently supported by Linux too. another book reference I found
was in POSIX.4 Programming for Real World by Bill O. Gallmeister, page
281. there it is written that additions are unconditional, if
_POSIX_VERSION is greater or equal than 199309 which is safe to assume
at this point of time I guess.
Signed-off-by: Ivailo Monev <xakepa10@gmail.com>
