Benchmarking
Java

New Methods in Java 9: Math.fma and Arrays.mismatch

There are two noteworthy new methods in Java 9: Arrays.mismatch and Math.fma. Arrays.mismatch This method takes two primitive arrays, and returns the index of the first differing values. This effectively computes the longest common prefix of the two arrays. This is really quite useful, mostly for text processing but also for Bioinformatics (protein sequencing and […]

Read More
Benchmarking
Data Structures
Java

Sorting Unsigned Integers Faster in Java

I discovered a curious resource for audio-visualising sort algorithms, which is exciting for two reasons. The first is that I finally feel like I understand Alexander Scriabin: he was not a composer. He discovered Tim Sort 80 years before Tim Peters and called it Black Mass. (If you aren’t familiar with the piece, fast-forward to […]

Read More
Benchmarking
Java

Targeting SIMD in Java

Vectorised instruction execution can be targeted directly in C++ but with Java there are extra layers of abstraction to go through. Folklore aside, when does vectorisation or SIMD execution actually happen in Java? Skeptical of old wives’ tales, I investigate when SIMD instructions are actually used in Java 9, and how to disable it by programming […]

Read More
Data Structures
Java

Microsecond Latency Rules Engine with RoaringBitmap

Implementing a rules engine can shorten development time and remove a lot of tedious if statements from your business logic. Unfortunately they are almost always slow and often bloated. Simple rules engines can be implemented by assigning integer salience to each line in a truth table, with rule resolution treated as an iterative intersection of […]

Read More
HTTP
Java

HTTP Content Negotiation

Ever had the situation where you’ve implemented a REST API, and then another team or potential customer comes along and asks if you could just change the serialisation format? Or maybe you are using a textual media type and want to experiment to see if performance would improve with a binary format? I see this […]

Read More