Ann: Working on mph algos

[Reini Urban]

I just ported the NetBSD nbperf code to linux, and found it quite useful.
3 new minimal perfect hash algos, with different space-time tradeoffs.

1. CHM with order preserving keyword array, which is esp. useful for range searches.
e.g. you search for the first hit, and can immediately get the next 10 keywords also.

2. efficiently generate minimal perfect hashes, esp. with >15.000 keywords. BPZ is

extremely space efficient, but if false-positives can be queried, the original list must be stored also.

Of course it's much slower than the default gperf algo, but for large lists gperf is not well
suited. Also the ordering property of CHM is nice.

Working here, merging it into main, search and output.

https://github.com/rurban/gperf/commits/nbperf

The original code: https://github.com/rurban/nbperf (BSD3 Licensed)

I'll bug assign@gnu for the assignment.

Do we need permission from the original author also, or is BSD enough?

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Reini Urban