RFR: JDK-8150496,(zipfs) Fix performance issues in zip-fs

[Xueming Shen]

Hi Aleksey,

The webrev has been updated accordingly.

http://cr.openjdk.java.net/~sherman/8150496/webrev

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

*) Parentheses to nail down eval order:
       if (w&&  zfs.isReadOnly() || x) {
     ...to:
       if ((w&&  zfs.isReadOnly()) || x) {

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

updated, but just like to know if this triggers performance difference?
not likely for me though.

yes, the performance gains still hold.

Benchmark                              Mode  Cnt     Score     Error  Units
-------------------------------new-------------------------------------------
MyBenchmark.ZFS_Exists                 avgt   50     4.140 ±   0.374  ms/op
MyBenchmark.ZFS_GetPath                avgt   50    12.521 ±   2.003  ms/op
MyBenchmark.ZFS_GetPathExists          avgt   50    20.931 ±   1.986  ms/op
MyBenchmark.ZFS_GetPathIsDirectory     avgt   50    25.531 ±   1.322  ms/op
MyBenchmark.ZFS_GetPathIsRegularFile   avgt   50    26.971 ±   2.957  ms/op
MyBenchmark.ZFS_GetPathNewInputStream  avgt   50    31.064 ±   1.542  ms/op
MyBenchmark.ZFS_GetPathToRealPath      avgt   50    20.506 ±   0.512  ms/op
MyBenchmark.ZFS_IsDirectory            avgt   50     8.935 ±   0.367  ms/op
MyBenchmark.ZFS_IsRegularFile          avgt   50     8.831 ±   0.505  ms/op
MyBenchmark.ZFS_Itr                    avgt   50    18.981 ±   0.367  ms/op
MyBenchmark.ZFS_Open                   avgt   50  1340.401 ± 204.590  ms/op
MyBenchmark.ZFS_ToRealPath             avgt   50     4.803 ±   0.450  ms/op
MyBenchmark.ZFS_newInputStream         avgt   50    14.687 ±   0.515  ms/op
-------------------------------old-------------------------------------------
MyBenchmark.ZFS_Exists                 avgt   50    10.475 ±  0.438  ms/op
MyBenchmark.ZFS_GetPath                avgt   50    12.199 ±  0.522  ms/op
MyBenchmark.ZFS_GetPathExists          avgt   50    27.345 ±  1.886  ms/op
MyBenchmark.ZFS_GetPathIsDirectory     avgt   50    29.667 ±  3.120  ms/op
MyBenchmark.ZFS_GetPathIsRegularFile   avgt   50    28.810 ±  2.455  ms/op
MyBenchmark.ZFS_GetPathNewInputStream  avgt   50   152.794 ±  3.628  ms/op
MyBenchmark.ZFS_GetPathToRealPath      avgt   50    36.499 ±  1.331  ms/op
MyBenchmark.ZFS_IsDirectory            avgt   50    10.887 ±  0.454  ms/op
MyBenchmark.ZFS_IsRegularFile          avgt   50    11.276 ±  0.410  ms/op
MyBenchmark.ZFS_Itr                    avgt   50    21.126 ±  0.729  ms/op
MyBenchmark.ZFS_Open                   avgt   50  1587.028 ± 90.858  ms/op
MyBenchmark.ZFS_ToRealPath             avgt   50    19.399 ±  0.613  ms/op


btw, it appears the jmh no longer "install" with the latest jdk9 repo. After I updated
the jdk9 repo, now "mvn clean install" throws exception showed below. But it runs
the benchmark fine. Maybe my jmh version is old?

  xueshen at sca00aky:/export/home/xueshen/jmh/jzf/test]mvn clean install
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building JMH benchmark sample: Java 1.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ test ---
[INFO] Deleting /export/home/xueshen/jmh/jzf/test/target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ test ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /export/home/xueshen/jmh/jzf/test/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ test ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /export/home/xueshen/jmh/jzf/test/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] Annotation generator had thrown the exception. java.lang.NoClassDefFoundError: javax/annotation/Generated
       at org.openjdk.jmh.generators.core.BenchmarkGenerator.generateImport(BenchmarkGenerator.java:575)
       at org.openjdk.jmh.generators.core.BenchmarkGenerator.generateClass(BenchmarkGenerator.java:533)
       at org.openjdk.jmh.generators.core.BenchmarkGenerator.generate(BenchmarkGenerator.java:94)
       at org.openjdk.jmh.generators.BenchmarkProcessor.process(BenchmarkProcessor.java:58)
       at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(jdk.compiler
....