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tidwall / geojson

GeoJSON for Go. Used by Tile38
MIT License
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Optimize point in ring #16

Closed mpoindexter closed 4 years ago

mpoindexter commented 4 years ago

Since ring is an interface, the compiler cannot prove that the closure created in ringContainsPoint is not needed after the call to ring.Search completes. This causes the closure to be allocated on the heap, reducing performance due to excessive heap allocations. In tile38, this is on the hot path for WITHIN commands on complex polygons.

Benchstat report for 10 runs of old an new code:

name               old time/op    new time/op    delta
BigTexas_RTree-12    1.09µs ± 3%    1.02µs ± 1%    -5.96%  (p=0.000 n=10+10)

name               old alloc/op   new alloc/op   delta
BigTexas_RTree-12     66.0B ± 0%      1.7B ±41%   -97.42%  (p=0.000 n=10+10)

name               old allocs/op  new allocs/op  delta
BigTexas_RTree-12      3.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)
tidwall commented 4 years ago

Thanks Mike! This is a really nice boost.