01.08.2019, 11:30, "Philip McGraw" <philip.mcg...@bentley.com>:
>> From: Andrey <ahi...@yandex.ru>
>> Sent: Wednesday, 31 July, 2019 21:35
>> To: Philip McGraw <philip.mcg...@bentley.com>
>> Cc: git@vger.kernel.org; l...@diamand.org
>> Subject: Re: [PATCH] git-p4: close temporary file before removing
>>
>> 31.07.2019, 17:52, "Philip McGraw" <philip.mcg...@bentley.com>:
>> > 2019.07.31 10:09 Andrey <ahi...@yandex.ru>
>> >> 31.07.2019, 09:53, "Philip McGraw" <philip.mcg...@bentley.com>:
>> >>>> 30.07.2019, 13:37, "Philip McGraw" <philip.mcg...@bentley.com>:
>> >>>> > python os.remove() throws exceptions on Windows platform when
>> attempting
>> >>>> > to remove file while it is still open. Need to grab filename
>> while file open,
>> >>>> > close file handle, then remove by name. Apparently other
>> platforms are more
>> >>>> > permissive of removing files while busy.
>> >>>> > reference:
>> >>>> > ---
>> >>>> > git-p4.py | 4 +++-
>> >>>> > 1 file changed, 3 insertions(+), 1 deletion(-)
>> >>>> >
>> >>>> > diff --git a/git-p4.py b/git-p4.py
>> >>>> > index c71a6832e2..6b9d2a8317 100755
>> >>>> > --- a/git-p4.py
>> >>>> > +++ b/git-p4.py
>> >>>> > @@ -1161,12 +1161,14 @@ def exceedsLargeFileThreshold(self,
>> relPath, contents):
>> >>>> > return False
>> >>>> > contentTempFile = self.generateTempFile(contents)
>> >>>> > compressedContentFile =
>> tempfile.NamedTemporaryFile(prefix='git-p4-large-file', delete=False)
>> >>>> > + compressedContentFileName = compressedContentFile.name
>> >>>> > zf = zipfile.ZipFile(compressedContentFile.name,
>> mode='w')
>> >>>> > zf.write(contentTempFile,
>> compress_type=zipfile.ZIP_DEFLATED)
>> >>>> > zf.close()
>> >>>> > compressedContentsSize =
>> zf.infolist()[0].compress_size
>> >>>> > os.remove(contentTempFile)
>> >>>> > - os.remove(compressedContentFile.name)
>> >>>> > + compressedContentFile.close()
>> >>>> > + os.remove(compressedContentFileName)
>> >>>>
>> >>>> I'm not sure why NamedTemporaryFile() is called with delete=False
>> above,
>> >>>> but it appears to me that it can have delete=True instead,
>> >>>> so that there is no need to call os.remove() explicitly
>> >>>> and thus worry about remove vs close ordering at all.
>> >>>>
>> >>>> > if compressedContentsSize > gitConfigInt('git-
>> p4.largeFileCompressedThreshold'):
>> >>>> > return True
>> >>>> > return False
>> >>>> > --
>> >>>> > 2.21.0.windows.1
>> >>>>
>> >>>> Thank you,
>> >>>> Andrey.
>> >>>
>> >>> Thanks Andrey; simpler is certainly better! I will test and re-submit
>> v2 of patch with that approach.
>> >>
>> >> Thank you, that would be great!
>> >>
>> >> --
>> >> Andrey.
>> >
>> > Unfortunately it wasn't as simple it seemed: upon testing with only
>> changing delete=True,
>> > found that the problem was not solved. Upon further debugging,
>> recoded/refactored slightly adding
>> > allocateTempFileName() locally scoped function to try to clarify how the
>> NamedTemporaryFile()
>> > was actually being used.
>> >
>> > We can't depend on the delete-on-close because the NamedTemporaryFile()
>> is merely allocating
>> > a temporary name for real use by the zipfile open-for-write which fails
>> (on Windows) if file
>> > was not explicitly closed first.
>>
>> Oh, sorry for misguiding you!
>> I didn't think of this aspect.
>
> No worries! I probably just misunderstood the implementation of your idea.
No, you understood what I was saying correctly.
It's just that I didn't think of opening the file twice.
(or rather that it would be a problem)
>> > Hopefully the new patch
>> (https://urldefense.proofpoint.com/v2/url?u=https-
>> 3A__github.com_gitgitgadget_git_pull_301&d=DwIDaQ&c=hmGTLOph1qd_VnCqj81HzE
>> WkDaxmYdIWRBdoFggzhj8&r=b0ikFMJGw7xxhF3yjexiWJpLuNxlAh1SvUDuUJ-
>> pHmE&m=1jGOrV_I1Mg5ajkJ7yFEcNlyLnD6zYNXqXB9Z5SIPyE&s=TdT4WHyQCk5WZty_CvajH
>> XgrZJbmIOl1gbMcngmjmAs&e= ) will make this more clear.
>>
>> The new changeset looks good to me.
>> (I'll post a reply in that thread too)
>>
>> > Open to other suggestions if still not clear.
>>
>> Just as a thought, ZipFile() can take a file-like object instead of a file
>> name,
>> so can be passed the NamedTemporaryFile() object directly instead of its
>> file name.
>> This should hopefully avoid double-open issue on Windows.
>
> Another excellent idea that minimizes changes. I am testing this approach
> now and will submit v3 of the patch soon.
Thank you for willing to try the new approach!
>> However, I'm good with your allocateTempFileName() changeset,
>> so it's up to you to give it a try or not.
>>
>> > Thanks again,
>> > Philip
>>
>> Thank you,
>> Andrey.
>
> Thanks,
> Philip
--
Andrey.
