On 20/06/2013 19:48, Xueming Shen wrote:
:
I'm proposing the following approach to add the functionality of
supporting
the "utc-date/time-with-1-second granularity" and keep the old behavior
of the get/setTime() of the ZipEntry.
(1) keep the time/setTime()/getTime() for the MS-DOS standard date/time.
To set via the old setTime() will only store the time into zip's
standard
date/time field, which is in MS-DOS date/time. And getTime() only
returns
the date/time from that field, when read from the zip file/stream.
(2) add mtime/set/getLastModifiedTime() to work on the UTC time fields,
and the last modified time set via the new method will also set
the "time",
and the getLastModifiedTime() also returns the "time", if the UTC
time
stamp fields are not set in the zip file header. The idea is that
for the new
application, the recommendation is to use
ZipEntry.set/getLastModifiedTime()
for better/correct time stamp, but the existing apps keep the
same behavior.
(3) jar and ZipOutputStream are updated to use the
set/getLastModifiedTime().
(4) Pack/unpack continues to use the set/getTime(), so the current
workaround
continues work. I will leave this to Kuma to decide how it should
be handled
going forward. (there are two facts need to be considered here,
a) the
existing jar file might not have the utc time instored, and b)
all "extra" data
are wiped out during the pack/unpacking process)
(5) additionally add another pair of atime/get/setLastAccessTime and
ctime/get/setCreationTime().
(6) The newly added 3 pairs of the m/a/ctime get/set methods use the
"new"
nio FileTime, instead of the "long". This may add some additional
cost of
conversion when working with them, but may also help improve the
performance if the time stamps are directly from nio file system
when
get/set XYZTime. Good/bad?
http://cr.openjdk.java.net/~sherman/8015666/webrev/
Comment, option and suggestion are appreciated.
At a high-level this looks a reasonable approach. An alternative would
be to define an API over the extra block but I don't think we want to go
there.
For consistency you might consider setTime setting mtime to null,
otherwise the ordering when both setXXX methods are used is significant.
Another thing to consider is whether the "parsing" of the extra block
could be changed to being lazy now as it's only interesting when someone
asks for it or the higher precision time stamps. Thinking back to the
original changes then I wonder if we discussed the UNIX extra field,
maybe you said that Windows tools can't handle such zip files?
A possible concern is that the footprint of ZipEntry increases. We could
eliminate this increase if the new methods operated on the extra block.
There's a clearly a trade-off here.
I spotted one or two "modificatin" in the javadoc, but I'll make time to
do a proof-read the javadoc once the approach is agreed.
-Alan.
