ShiKaiWi 518ee55d78 expvar: improve Map.addKey for large number of keys ... The existing implementation has poor performance for inserting large number of keys because it chooses to append the new key to the sorted keys array and then sort the new array again (time complexity is O(nlogn)). The improvement tries to utilize the sorted keys array by searching the index and doing an insertion if any (time complexity is O(logn)). Benchmarked on 4-core machine with `go test -cpu 1,2,4,8 -count 5 -benchmem -bench=.`(the equal results are omitted): name old time/op new time/op delta MapAddDifferentRandom-8 408µs ±11% 69µs ± 3% -82.95% (p=0.008 n=5+5) MapAddDifferentRandom-4 389µs ±19% 69µs ± 2% -82.28% (p=0.008 n=5+5) MapAddDifferentRandom-2 365µs ± 4% 75µs ± 6% -79.51% (p=0.008 n=5+5) MapSetDifferentRandom-8 365µs ± 4% 76µs ±40% -79.07% (p=0.008 n=5+5) MapAddDifferentRandom 366µs ± 3% 78µs ± 6% -78.66% (p=0.008 n=5+5) MapSetDifferentRandom 369µs ± 2% 81µs ±34% -77.99% (p=0.008 n=5+5) MapSetDifferentRandom-2 378µs ±10% 100µs ±32% -73.47% (p=0.008 n=5+5) MapSetDifferentRandom-4 352µs ± 4% 108µs ± 7% -69.40% (p=0.008 n=5+5) IntAdd-2 23.1ns ±21% 15.5ns ±23% -32.79% (p=0.032 n=5+5) IntSet-2 21.4ns ±14% 16.7ns ±17% -22.00% (p=0.016 n=5+5) FloatAdd-8 88.8ns ± 9% 70.8ns ±25% -20.23% (p=0.024 n=5+5) FloatSet-2 22.3ns ±15% 17.8ns ±14% -20.14% (p=0.008 n=5+5) IntAdd-8 21.7ns ± 3% 18.7ns ± 4% -14.00% (p=0.008 n=5+5) MapAddDifferent-8 1.58µs ± 7% 1.42µs ± 6% -10.06% (p=0.016 n=5+5) StringSet-2 42.4ns ± 1% 43.7ns ± 5% +3.07% (p=0.048 n=4+5) FloatSet 8.27ns ± 2% 8.60ns ± 1% +3.94% (p=0.008 n=5+5) FloatAdd 12.5ns ± 2% 13.0ns ± 4% +4.33% (p=0.032 n=5+5) MapSetString-4 94.6ns ± 0% 101.7ns ± 4% +7.55% (p=0.016 n=4+5) MapAddSameSteadyState-2 34.9ns ± 3% 37.7ns ± 5% +8.14% (p=0.008 n=5+5) StringSet-4 34.5ns ± 0% 37.6ns ± 9% +9.02% (p=0.016 n=4+5) MapSetDifferent-8 377ns ± 3% 411ns ± 7% +9.07% (p=0.008 n=5+5) MapAddSameSteadyState 39.1ns ± 2% 42.8ns ± 6% +9.36% (p=0.008 n=5+5) MapAddDifferentSteadyState 172ns ± 4% 190ns ± 9% +10.96% (p=0.016 n=5+5) MapSet 143ns ± 4% 159ns ± 2% +11.06% (p=0.008 n=5+5) MapSet-4 96.9ns ± 5% 107.8ns ± 6% +11.25% (p=0.008 n=5+5) MapSet-2 102ns ± 6% 114ns ± 8% +11.94% (p=0.008 n=5+5) IntSet 8.18ns ± 1% 12.78ns ±13% +56.31% (p=0.008 n=5+5) name old alloc/op new alloc/op delta MapSetDifferentRandom-4 19.8kB ± 0% 16.6kB ± 0% -16.21% (p=0.008 n=5+5) MapSetDifferentRandom 19.8kB ± 0% 16.6kB ± 0% -16.21% (p=0.008 n=5+5) MapSetDifferentRandom-8 19.8kB ± 0% 16.6kB ± 0% -16.20% (p=0.008 n=5+5) MapSetDifferentRandom-2 19.8kB ± 0% 16.6kB ± 0% -16.20% (p=0.008 n=5+5) MapAddDifferentRandom 20.6kB ± 0% 17.4kB ± 0% -15.57% (p=0.008 n=5+5) MapAddDifferentRandom-8 20.6kB ± 0% 17.4kB ± 0% -15.57% (p=0.008 n=5+5) MapAddDifferentRandom-2 20.6kB ± 0% 17.4kB ± 0% -15.56% (p=0.008 n=5+5) MapAddDifferentRandom-4 20.6kB ± 0% 17.4kB ± 0% -15.56% (p=0.008 n=5+5) MapAddDifferent 1.09kB ± 0% 0.96kB ± 0% -11.76% (p=0.008 n=5+5) MapAddDifferent-2 1.09kB ± 0% 0.96kB ± 0% -11.76% (p=0.008 n=5+5) MapAddDifferent-4 1.09kB ± 0% 0.96kB ± 0% -11.76% (p=0.008 n=5+5) MapAddDifferent-8 1.09kB ± 0% 0.96kB ± 0% -11.76% (p=0.008 n=5+5) MapAddSame 480B ± 0% 448B ± 0% -6.67% (p=0.008 n=5+5) MapAddSame-2 480B ± 0% 448B ± 0% -6.67% (p=0.008 n=5+5) MapAddSame-4 480B ± 0% 448B ± 0% -6.67% (p=0.008 n=5+5) MapAddSame-8 480B ± 0% 448B ± 0% -6.67% (p=0.008 n=5+5) name old allocs/op new allocs/op delta MapSetDifferentRandom 423 ± 0% 323 ± 0% -23.64% (p=0.008 n=5+5) MapSetDifferentRandom-2 423 ± 0% 323 ± 0% -23.64% (p=0.008 n=5+5) MapSetDifferentRandom-4 423 ± 0% 323 ± 0% -23.64% (p=0.008 n=5+5) MapSetDifferentRandom-8 423 ± 0% 323 ± 0% -23.64% (p=0.008 n=5+5) MapAddDifferentRandom 523 ± 0% 423 ± 0% -19.12% (p=0.008 n=5+5) MapAddDifferentRandom-2 523 ± 0% 423 ± 0% -19.12% (p=0.008 n=5+5) MapAddDifferentRandom-4 523 ± 0% 423 ± 0% -19.12% (p=0.008 n=5+5) MapAddDifferentRandom-8 523 ± 0% 423 ± 0% -19.12% (p=0.008 n=5+5) MapAddDifferent 31.0 ± 0% 27.0 ± 0% -12.90% (p=0.008 n=5+5) MapAddDifferent-2 31.0 ± 0% 27.0 ± 0% -12.90% (p=0.008 n=5+5) MapAddDifferent-4 31.0 ± 0% 27.0 ± 0% -12.90% (p=0.008 n=5+5) MapAddDifferent-8 31.0 ± 0% 27.0 ± 0% -12.90% (p=0.008 n=5+5) MapAddSame 11.0 ± 0% 10.0 ± 0% -9.09% (p=0.008 n=5+5) MapAddSame-2 11.0 ± 0% 10.0 ± 0% -9.09% (p=0.008 n=5+5) MapAddSame-4 11.0 ± 0% 10.0 ± 0% -9.09% (p=0.008 n=5+5) MapAddSame-8 11.0 ± 0% 10.0 ± 0% -9.09% (p=0.008 n=5+5) Fixes #31414 Change-Id: I2dd655dec9dbbf8d7881a0f3f8edcb3d29199a48 GitHub-Last-Rev: a816fe3f62 GitHub-Pull-Request: golang/go#31418 Reviewed-on: https://go-review.googlesource.com/c/go/+/171718 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>		2019-04-16 17:18:01 +00:00
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expvar_test.go	expvar: improve Map.addKey for large number of keys	2019-04-16 17:18:01 +00:00
expvar.go	expvar: improve Map.addKey for large number of keys	2019-04-16 17:18:01 +00:00