superwings-spinel

Find the nearest airport from (lat, lng) coordinates — the superwings API, computed by a Ruby port of the airport_finder crate compiled to native code by Spinel, Matz's Ruby AOT compiler.

from superwings_spinel import AirportSet, airport, country_at, find_nearest_airport

find_nearest_airport(37.5665, 126.978)
# {'code': 'kr.gmp', 'name': 'Seoul, Korea'}

country_at(-29.31, 27.48)
# 'ls'

hubs = AirportSet(["HYD", "BOM", "BCN"])
hubs.resolve(17.385, 78.486, foreign_max_km=300)
# {'code': 'in.hyd', 'iata': 'HYD', 'name': 'Hyderabad, India', ...,
#  'distance_km': 18.09828547178263, 'resolution': 'same_country', 'nearest_code': 'in.bpm'}
hubs.nearest(19.07, 72.87, country="IN", limit=2)

Functions, dicts and errors are superwings 0.3.0's: import superwings_spinel as superwings is enough to switch. The answers are the crate's, bit for bit on 150,403 test points, with one difference from superwings 0.3.0, which bundles the crate's 0.3.1: an enclave is its own country. Maseru is Lesotho (ls), not South Africa; 0.3.1 answered za across all of Lesotho.

Speed

The Rust wheel is faster, by about as much as the compiled code is. From Python on an Apple M1 (superwings in parentheses): find_nearest_airport takes 6 µs near airports (3.6 µs) and 25 µs anywhere (14 µs); AirportSet.nearest(limit=5) 8.6 µs (6.6 µs), resolve 9 µs (4.6 µs), airport 1 µs (0.8 µs). Loading the data on the first call takes about 33 ms (26 ms).

The library answers with numbers: airports by index, with distances. The module makes an airport's dict the first time that airport comes up and hands out copies, so a call formats and parses nothing (0.1.0 passed JSON: 2–4× superwings). The dicts kept come to about 8 MB if every airport has come up.

Notes

• The library takes one call at a time; the module serializes calls from threads with a lock.
• Wheels carry no Python extension (the library is loaded with ctypes), so one wheel per platform serves every Python 3.9+. Elsewhere the sdist builds with a C compiler alone.
• $SUPERWINGS_SPINEL_LIB points the module at another build of the library.

License

MIT. The library includes Spinel's runtime (MIT); see THIRD_PARTY_NOTICES.