It pre-compiles routes to a prefix trie [0], which allows it to match any route in one run by walking down the tree rather than trying each route from scratch. Nginx uses the same strategy for static routes.

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0. https://en.wikipedia.org/wiki/Trie

R3 does look fast, but there's a cost to crossing the JS -> C barrier. It's almost certainly possible to beat it using the same algorithm written in pure JS.

Finding a match in a tree structure is asymptotically O(log n), finding a match in a list is O(n). This router is also written in C.

There is a benchmark in the README comparing R3 to the Rails router and also to a replacement Rails router that I wrote for non-performance related reasons.

It should be noted that usually only a tiny proportion of the time taken to respond to a request is spent in route recognition. YMMV.

It's a binding library of r3, you may check the benchmark from r3 project:

https://github.com/c9s/r3#performance