Change-Id: Iad0bcc01ada4252e9ab4f60d4375f98f084f6a5f
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I326377c90af59ecaada7f5185a638726a8e909b7
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: Iae4524ddc730d57993e9c6d6807282e4b07d1336
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

The source code in the folder .apt_generated is generated by the JMH
code generator, so there's no point in raising any warnings as this
could only be fixed in the upstream code generator.

Change-Id: I882888e7bf924f9ae74182598fcb91671a5c9818
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I11afc45141da988e28382898246995f6b45eb09c
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Also fix indentation.

Change-Id: I6d223c493d537bb8aac23c7ddf0a602aff22a3c2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

The benchmarks can be built and run using bazel by running:

$ bazel run //org.eclipse.jgit.benchmarks:benchmarks

Change-Id: I6679750eaa0f2be30ed9d45036e013b0ea4fcc86
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I953fd8b6b9743b0b9cada244331253eb2121784d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Results on Mac OS 10.14.6 using APFS:

Result "org.eclipse.jgit.benchmarks.LookupFileStoreBenchmark.testLookupFileStore":
  44583.277 ±(99.9%) 2666.096 ns/op [Average]
  (min, avg, max) = (43707.073, 44583.277, 45320.685), stdev = 692.377
  CI (99.9%): [41917.181, 47249.373] (assumes normal distribution)

Secondary result
"org.eclipse.jgit.benchmarks.LookupFileStoreBenchmark.testLookupFileStore:·stack":
Stack profiler:

....[Thread state
distributions]........................................................
100.0%         RUNNABLE

....[Thread state:
RUNNABLE].............................................................
 42.5%  42.5% sun.nio.fs.UnixNativeDispatcher.realpath0
 37.9%  37.9% sun.nio.fs.UnixNativeDispatcher.stat0
 11.0%  11.0% sun.nio.fs.BsdNativeDispatcher.getfsstat
  7.6%   7.6% sun.nio.fs.BsdNativeDispatcher.fsstatEntry
  0.7%   0.7% sun.nio.fs.BsdNativeDispatcher.endfsstat
  0.1%   0.1% sun.nio.fs.UnixPath.initOffsets
  0.0%   0.0% sun.nio.fs.UnixFileAttributes.get
  0.0%   0.0% java.util.zip.Inflater.inflateBytes
  0.0%   0.0% sun.misc.Unsafe.compareAndSwapInt
  0.0%   0.0% sun.nio.fs.BsdFileStore.findMountEntry

This shows that FS.attrCacheByPath should be useful to reduce overhead
of looking up the FileStore of a given file.

Change-Id: I7213086b42e0453f0ee149660d507dac2a4644cc
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

See [1] for JMH documentation and [2] how to use JMH in Eclipse.

The benchmarks pom currently cannot use the JGit parent pom due to an
ecj bug [3] regarding annotation processing. Hence for now do not
inherit from the JGit parent pom and copy the compiler plugin
configuration for javac from the parent pom.

After running the Maven build the benchmark can be run using Maven:

$ java -jar org.eclipse.jgit.benchmarks/target/benchmarks.jar

or in Eclipse by running the main method of the SimpleLruCacheBenchmark
class.

[1] https://openjdk.java.net/projects/code-tools/jmh/
[2] http://alblue.bandlem.com/Page/3/index.html
[3] https://eclip.se/532029

CQ: 20517
CQ: 20518
Change-Id: Idca8a9e0980f0b8a9c741c4c9e97d03c62f07c8d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>