chiark / gitweb /
journal: optimize iteration by returning previously found candidate entry
In next_beyond_location() when the JournalFile's location type is
LOCATION_SEEK, it means there's nothing to do, because we already have
the location of the candidate entry. Do an early return. Note that now
next_beyond_location() does not anymore guarantee on return that the
entry is mapped, but previous patches made sure the caller does not
care.
This optimization is at least as good as "journal: optimize iteration:
skip files that cannot improve current candidate entry" was.
Timing results on my workstation, using:
$ time ./journalctl -q --since=2014-06-01 --until=2014-07-01 > /dev/null
Before "Revert "journal: optimize iteration: skip files that cannot
improve current candidate entry":
real 0m5.349s
user 0m5.166s
sys 0m0.181s
Now:
real 0m3.901s
user 0m3.724s
sys 0m0.176s