RFR: 8015666: test/tools/pack200/TimeStamp.java failing
Kumar Srinivasan
kumar.x.srinivasan at oracle.com
Tue Aug 6 21:57:06 UTC 2013
Hi Sherman,
The code changes look good to me, I was thinking about the test and
here are some observations:
test/java/util/zip/TestExtraTime.java
a. you have TZ of Asia/Shanghai, I am wondering if it would help to add
a TZ which
has DST for any DST computation issues that we might encounter.
Also perhaps a tests which zips a file in one TimeZone and test in another
TimeZone ?
If these are being addressed by SQE that is fine.
b. this test sets the default TimeZone, this could cause weird issues
for other downstream
tests, specifically when jtreg runs in the samevm or agentvm mode, so
either we run this test in a
discrete VM or reset the TimeZone using a finally.
Thanks
Kumar
> Kumar, Alan,
>
> Here is the latest webrev of the changes based on the latest CCC.
>
> http://cr.openjdk.java.net/~sherman/8015666/webrev
>
> -Sherman
>
>
> On 07/02/2013 11:29 AM, Xueming Shen wrote:
>> On 06/28/2013 07:47 AM, Kumar Srinivasan wrote:
>>> Some nits while reading the changes:
>>> 1. ZipEntry.java
>>> a. typo:
>>>
>>> + * Sets the laste access time of the entry.
>>>
>>>
>>> b. extra space
>>>
>>> + case EXTID_ZIP64 :
>>>
>>> 2. ZipOutputStream.java
>>> I think it would be nice to have the flags 0x1, 0x2 and 0x4 defined
>>> as constants, this will also help a casual reader as to what this
>>> means.
>>>
>>>
>>> Besides my previous concern with finish(), everything else appears
>>> to be ok.
>>
>> Kumar,
>>
>> I have the dostime "cached" in XEntry, so the writeCEN() and
>> writeLOC() will
>> always write out the same local msdos time. The cache should help the
>> perf
>> a little, as the javaToDosTime() now only invoked once for the same
>> entry.
>>
>> Nothing needs to be updated in unpack side now. (I took a look at the
>> API,
>> it appears there is no way to do anything on unpack side to workaround
>> this issue, without the possibility of breaking someone's code)
>>
>> http://cr.openjdk.java.net/~sherman/8015666/webrev/
>>
>> -Sherman
>>
>>>
>>> Kumar
>>>
>>>
>>>> On 06/27/2013 10:04 AM, Kumar Srinivasan wrote:
>>>>> Hi Sherman,
>>>>>
>>>>> I started looking at this, my initial comment, the Unpacker.unpack
>>>>> does not close its output and we allow multiple pack files to be
>>>>> concatenated,
>>>>> I am assuming out.finish() will allow further jar files to be
>>>>> appended ?
>>>>> or would this cause a problem ?
>>>>
>>>> No, out.finish() will not allow further entry appending. Then, it
>>>> appears
>>>> we need to have a different approach to "finish" the
>>>> Jar/ZipOutputStream.
>>>> What need to be done here is that either out.close/finish() need to be
>>>> invoked under the UTC locale as well (to output the time stamps in cen
>>>> table correctly). This is another "incompatible" change of the
>>>> previous
>>>> change, in which the msdosTime<->javaTime conversion no longer
>>>> occurs during the ZipEntry.set/getTime(), but during the read and
>>>> write
>>>> the ZipEntry from/to the zip file.
>>>>
>>>> -Sherman
>>>>
>>>>
>>>>>
>>>>> Kumar
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> The zip time related changes[1] I pushed back last month appears
>>>>>> to have the compatibility risk of breaking existing code. The main
>>>>>> idea in that changeset is to use the more accurate and timezone
>>>>>> insensitive utc time stored in the extra field for the
>>>>>> ZipEntry.set/getTime()
>>>>>> if possible. However it turns out the reality is that the code
>>>>>> out there
>>>>>> might have already had some interesting workaround/hack solution
>>>>>> to workaround the problem that the time stamp stored in the
>>>>>> "standard'
>>>>>> zip entry header is a MS-DOS standard date/time, which is a "local
>>>>>> date/time" and sensitive to timezone, in which, if the zip is
>>>>>> archived
>>>>>> in time zone A (our implementation converts the "java" time to dos
>>>>>> time by using the default tz A) and then transferred/un-archived in
>>>>>> a different zone B (use default tz B to convert back to java
>>>>>> time), we
>>>>>> have a time stamp mess up. The "workaround" from pack200 for this
>>>>>> issue when pack/unpacking a jar file is to
>>>>>> "specify/recommend/suggest"
>>>>>> in its spec that the "time zone" in a jar file entry is assumed
>>>>>> to be "UTC",
>>>>>> so the pack/unpack200 implementation set the "default time" to utc
>>>>>> before the pack/unpack and set it back to the original after
>>>>>> that. It worked
>>>>>> "perfectly" for a roundtrip pack/unpacking, until the changeset
>>>>>> [2], in
>>>>>> which ZipEntry.getTime() (packing) returns a real utc time and
>>>>>> the following
>>>>>> ZipEntry.setTime() (unpacking), then mess up the MS-DOS date/time
>>>>>> entry, this is the root cause of this regression.
>>>>>>
>>>>>> Given the facts that
>>>>>> (1) there are actually two real physical time stamps in a zip
>>>>>> file header,
>>>>>> one is in the date/time fields, which is
>>>>>> MS-DOS-local-date/time-with-2-
>>>>>> seconds-granularity , one is in the extra data field, which is
>>>>>> UTC-1-second
>>>>>> -granularity
>>>>>> (2) and there are applications over there that have dependency on
>>>>>> the
>>>>>> MS-DOS date/time stamp.
>>>>>>
>>>>>> 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.
>>>>>>
>>>>>> -Sherman
>>>>>>
>>>>>> [1] http://hg.openjdk.java.net/jdk8/tl/jdk/rev/90df6756406f
>>>>>
>>>>
>>>
>>
>
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