On 2/25/15 4:17 PM, Claes Redestad wrote:
We could preserve precision by shifting the remaining milliseconds
into the dostime field,
since the DOS time will only use the 4 lower bytes:
http://cr.openjdk.java.net/~redestad/jdk9/8073497/webrev.4/
After I went through more extensive testing and verification I
realized that narrowing
dostime to an int and breaking this remainder hack out into a separate
field would be
possible without affecting ZipEntry footprint; arguably cleaner, but
if this version is
acceptable I would prefer not to.
Going this way preserves precision across the entire input range of
setTime, thus all tests
I could find pass with this version; I've also expanded the
TestExtraTime test to test both
far ancient, far future and near future times to verify precision is
preserved.
I backpedaled on the getLastModifiedTime optimization to set the mtime
field that Peter
suggested since it would have the side-effect that the extra time
field would be written
after a call to this getter, which would be a bit too unexpected.
Thanks!
/Claes
Hi Claes,
It's a good idea! Given the upper half now covers that 2000 million
seconds, the "dostime" field
is no longer a real "dos time", just wonder if we can go a little
further. For example simply move
the bits for years/months/days/hours/minutes/seconds out (left) a little
more, 11(?) bits, to leave
the lower bits for the 2000 million seconds. The benefit is that the
upper bound is no longer needed.
We need a pair of package private set/getDostime() for ZIS, ZOS and ZF
to access though. Yes,
it costs a little left/right bit-shift when to set/get the dostime, but
it does not requires the
expensive j.u.Date/timezone.
-Sherman
