RFR: 8260617: Merge ZipFile encoding check with the initial hash calculation

[Claes Redestad]

On Fri, 29 Jan 2021 00:54:46 GMT, Claes Redestad <redestad at openjdk.org> wrote:

> - Merge checkEncoding into the byte[]-based normalizedHash. The latter is only used from ZipFile.initCEN right after the checkEncoding today, so verifying this is equivalent is straightforward.
> - Factor out the logic to calculate hash, check encoding etc into the addEntry method to allow JITs to chew off larger chunks of the logic early on
> 
> Roughly 1.2x speedup on the JarFileMeta microbenchmarks, which include the time required to open the jar file and thus exercising the optimized code.
> 
> Testing: tier1-4

Baseline:
Benchmark                                       (size)  Mode  Cnt    Score    Error  Units
JarFileMeta.getManifestFromJarWithManifest         512  avgt    5  246.534 ± 32.934  us/op
JarFileMeta.getManifestFromJarWithManifest        1024  avgt    5  475.978 ± 70.689  us/op
JarFileMeta.getStreamFromJarWithManifest           512  avgt    5  243.401 ± 33.190  us/op
JarFileMeta.getStreamFromJarWithManifest          1024  avgt    5  465.899 ± 58.306  us/op
JarFileMeta.getStreamFromJarWithNoManifest         512  avgt    5  243.480 ± 44.631  us/op
JarFileMeta.getStreamFromJarWithNoManifest        1024  avgt    5  454.937 ± 55.268  us/op
JarFileMeta.getStreamFromJarWithSignatureFiles     512  avgt    5  267.522 ± 48.914  us/op
JarFileMeta.getStreamFromJarWithSignatureFiles    1024  avgt    5  509.779 ± 81.314  us/op

Patched:
JarFileMeta.getManifestFromJarWithManifest         512  avgt    5  186.973 ± 26.564  us/op
JarFileMeta.getManifestFromJarWithManifest        1024  avgt    5  360.141 ± 33.414  us/op
JarFileMeta.getStreamFromJarWithManifest           512  avgt    5  186.244 ± 30.014  us/op
JarFileMeta.getStreamFromJarWithManifest          1024  avgt    5  362.870 ± 61.271  us/op
JarFileMeta.getStreamFromJarWithNoManifest         512  avgt    5  182.841 ± 13.797  us/op
JarFileMeta.getStreamFromJarWithNoManifest        1024  avgt    5  354.254 ± 67.377  us/op
JarFileMeta.getStreamFromJarWithSignatureFiles     512  avgt    5  215.419 ± 20.463  us/op
JarFileMeta.getStreamFromJarWithSignatureFiles    1024  avgt    5  403.043 ± 78.926  us/op

-------------

PR: https://git.openjdk.java.net/jdk/pull/2306