Improve performance of SimpleTimeFormat

ocpsoft / prettytime

Social Style Date and Time Formatting for Java

http://ocpsoft.org/prettytime/

Apache License 2.0

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Improve performance of SimpleTimeFormat #192

Closed theigl closed 4 years ago

theigl commented 4 years ago

String formatting in PrettyTime frequently shows up in my JFR profiler. It really should not, because it only performs basic string operations.

This PR applies two simple optimizations to SimpleTimeFormat:

Precompile pattern for collapsing consecutive whitespace into one
Use non-regex String.replace instead of String.replaceAll for simple replacements

The optimized version is nearly 4 times faster:

Benchmark	Mode	Cnt	Score	Units
Benchmarks.minutesAgoBaseline	thrpt	6	790712,507	ops/s
Benchmarks.minutesAgoOptimized	thrpt	6	3008068,573	ops/s

theigl commented 4 years ago

@lincolnthree: Please review.

lincolnthree commented 4 years ago

Hey @theigl apologies for the delay. Crazy around here with the launch of www.topdecked.com approaching. This looks great, will get it released ASAP.

theigl commented 4 years ago

Thanks @lincolnthree! And all the best for your launch!

lincolnthree commented 4 years ago

V 4.0.6.Final has been released to Sonatyle OSSRH staging/releases repo and should be available in Maven Central after tonight's nightly sync. Thanks so much for this performance enhancement!

I'm surprised nobody noticed this before, as it's a huge improvement/hotspot fix.

lincolnthree commented 4 years ago

Also thank you :) Not much sleep around here right now!