ben-manes / caffeine
99%

DEFAULT BRANCH: master
Repo Added
Files 78
Badge
Embed ▾
README BADGES
x

If you need to use a raster PNG badge, change the '.svg' to '.png' in the link

Markdown

Textile

RDoc

HTML

Rst

LAST BUILD ON BRANCH master
branch: SELECT
CHANGE BRANCH
x

coverage: 99.053% (-0.01%) from 99.065%
#4635

push

github

ben-manes 
optimize the frequency sketch

In an earlier analysis the block-based sketch was significantly faster
than the flat (uniform) one. This was independently confirmed by a C#
and Go port, who also observed a 2x speed up. However, when recently
adding this benchmark to the CI it showed it as a regression. Therefore
some implicit compiler optimizations are now explicit, which allows the
block-based sketch to match or exceed the flat-based performance.

- We no longer rely on escape analysis to optimize away the method
scoped arrays (count, index). These should have been stack allocated
and broken into their components.
- The arrays were meant to break a loop data dependency, but it is now
faster to keep that. `Math.min` is a single cycle, branch-free
instruction that the OOO pipeline seems to prefer.
- `increment` is manually loop unrolled like the flat version, which
shows a simiar speed up.
- Previously, the flat benchmark version implemented the scaffolding
interface directly, was pre-allocated, and the init guard was removed.
This gave it a large advantage as it improved inlining, branch
prediction, etc. The benchmark is now fair.
- For jdk11 the block is always faster by at least 10M ops/s. In jdk23
the speedup only occurs as the table size increases, matching the
expected gains from better cache effects. It is marginally slower on
the small table size due to indexing differences.

The differences are very hardware and compiler dependent, as there are
wide variations when running on Intel, Arm, Java versions, and JVMs
(Graal vs C2). The user effect will be noise since this was not a
performance bottleneck due to the cache's overall design.

21 of 21 new or added lines in 1 file covered. (100.0%)

1 existing line in 1 file now uncovered.

7634 of 7707 relevant lines covered (99.05%)

0.99 hits per line

Relevant lines Covered
7707 RELEVANT LINES 7634 COVERED LINES
0.99 HITS PER LINE
Source Files on master

Recent builds

Builds Branch Commit Type Ran Committer Via Coverage
#4635 master optimize the frequency sketch In an earlier analysis the block-based sketch was significantly faster than the flat (uniform) one. This was independently confirmed by a C# and Go port, who also observed a 2x speed up. However, when recently adding... push ben-manes github
99.05
#4634 v3.dev optimize the frequency sketch In an earlier analysis the block-based sketch was significantly faster than the flat (uniform) one. This was independently confirmed by a C# and Go port, who also observed a 2x speed up. However, when recently adding... push ben-manes github
99.05
#4633 v3.dev optimize the frequency sketch In an earlier analysis the block-based sketch was significantly faster than the flat (uniform) one. This was independently confirmed by a C# and Go port, who also observed a 2x speed up. However, when recently adding... push ben-manes github
99.04
#4632 master dependency updates push ben-manes github
99.06
#4631 master include method parameters in class file for use by static analyzers This allows errorprone to now detects ArgumentSelectionDefectChecker, BooleanParameter, and ParameterName warnings (now resolved). The jar size changes are negligible because we ... push ben-manes github
99.04
#4630 v3.dev include method parameters in class file for use by static analyzers This allows errorprone to now detects ArgumentSelectionDefectChecker, BooleanParameter, and ParameterName warnings (now resolved). The jar size changes are negligible because we ... push ben-manes github
99.04
#4629 v3.dev include method parameters in class file for use by static analyzers This allows errorprone to now detects ArgumentSelectionDefectChecker and ParameterName warnings, which are now resolved. The jar size changes are negligible because we exclude th... push ben-manes github
99.05
#4628 v3.dev fix warnings flagged by ArgumentSelectionDefectChecker https://github.com/ben-manes/caffeine/commit/8b835c96a#diff-1c22230ac7f800953335f1c22c4b84841R122 push ben-manes github
99.05
#4627 master Use the ToolProvider SPI to run google-java-format (#1795) This makes the compile-time dependency on google-java-format optional. push ben-manes github
99.03
#4626 v3.dev Use the ToolProvider SPI to run google-java-format This makes the compile-time dependency on google-java-format optional. Co-authored-by: Ben Manes <ben.manes@gmail.com> push ben-manes github
99.03
See All Builds (3658)