+1
Naoto
On 4/22/20 9:13 AM, Lance Andersen wrote:
Hi Claes,
The latest version looks good.
Thank you for the patch.
Best
Lance
On Apr 22, 2020, at 6:26 AM, Claes Redestad <[email protected]> wrote:
Hi,
new webrev based on discussions here and offline:
http://cr.openjdk.java.net/~redestad/8243254/open.01/
- creates a new testng test TestZipFileEncodings, which derives from
TestZipFile rather than repurposing that existing test. There is
definitely some overlap, but since TestZipFile is only run manually
and this new test runs fine (and quickly) in our testing I think
that's fine
- only implements the optimization for UTF-8, removing the concept
of ASCII-compatible ZipCoders.
- a few other cleanups
Testing: tier1+2
Thanks!
/Claes
On 2020-04-21 15:52, Claes Redestad wrote:
Hi,
ZipFile.getEntry does optimizations to check for directory entries by
adding a '/' to the encoded byte array. JDK-8242959 improved on this
optimization, but a question was raised Jason Zaugg on whether the
optimization is always valid[1]. Turns out it isn't, but only for
non-ASCII compatible charsets.
While JarFiles are always assumed to be UTF-8-encoded or compatible,
ZipFiles allow arbitrary encoding. E.g., UTF-16 would encode '/' (2F) as
either 2F 00 or 00 2F, which means the hash code would differ and a
directory "foo/" potentially not be found when looking up "foo". Further
complications arise when/if the directory name ends with a code point
that might be encoded so that the final byte is 2F, e.g. \u012F.
This patch only enables this low-level optimization when the charset
encoding used is known to be ASCII compatible in the sense that 2F will
be encoded as single-byte 2F. UTF-8 is compatible in this sense - and
since this is the charset exclusively used by JarFile these changes have
little to no effect on startup performance in the cases we've been
looking at.
Webrev: http://cr.openjdk.java.net/~redestad/8243254/open.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8243254
I've partially repurposed ZipFile/TestZipFile to test some such corner
cases. Mainly expanded it to test ZipFiles created with various non-
standard encodings, but also slimmed it down so that it can actually run
quickly and reliably - as well as enabled it in regular testing. The
updated test fails both before and after JDK-8242959, but passes with
the proposed changes.
Testing: tier1+2
Thanks!
/Claes
[1] https://twitter.com/retronym/status/1252134723431747584?s=20
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<http://oracle.com/us/design/oracle-email-sig-198324.gif>Lance Andersen|
Principal Member of Technical Staff | +1.781.442.2037
Oracle Java Engineering
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[email protected] <mailto:[email protected]>
