Performance Measurments Slow

[yancyribbens]

I recently ran a comparison between different coin-selection implementations, namely bitcoin-core, rust-bitcoin-coin-selection and this crate, bdk coin select. In so doing, I noticed BDK coin-select is slow, like really really slow.

These are the numbers I recently recorded:

implementation	interface	pool size	ns/select
bitcoin-coin-selection	select_coins()	400	862,910
bitcoin core	AttemptSelection()	400	16,695,408
bdk coin-select	run_bnb(lowest_fee)	50	30,202,000

To make matters worse, both bitcoin-core and bitcoin-coin-selection actually run the interface in a loop 10 times for each measurement.

For more details on the measurements, see my PR for adding coin-selection Criterion measurements here.

Hopefully these findings can help you all in fine tuning the performance of this crate.

[evanlinjin]

@yancyribbens thank you for sharing this. There is a bunch of work still in progress to optimise coin-select.

#79

Hopefully you'll find that performance has improved greatly.

[yancyribbens]

Thanks for the update on PR 79. I tests the results from that branch, and here is how bdk would compare with other algorithms:

implementation	interface	pool size	ns/select
bitcoin-coin-selection	select_coins()	400	862,910
bitcoin core	AttemptSelection()	400	16,695,408
bdk coin-select	run_bnb(lowest_fee)	100	12,444,000

Keep in mind as previously noted that both core and bitcoin-coin-selection run the selection 10 times per measurement. So the results show BDK is about 40 times slower once that is factored in. This is an improvement at least from before in that it looks like it's about 4 times faster than it used to be.