RFR: 8015666: test/tools/pack200/TimeStamp.java failing (original) (raw)

Alan Bateman Alan.Bateman at oracle.com
Fri Jun 21 13:33:08 UTC 2013

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.

More information about the core-libs-dev mailing list