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| author | Julian Schurhammer <julian.schurhammer@gmail.com> | 2022-08-14 22:46:39 +1200 |
|---|---|---|
| committer | Louis Pilfold <louis@lpil.uk> | 2023-03-13 10:49:34 +0000 |
| commit | a3e856bcfc32382c0001bbf51c1f4e14acc21bda (patch) | |
| tree | c534130d12c4d13d207894bf575779d6e5b6b2b7 /src | |
| parent | 3522d9a57a7ce8c54f57772a89e9ac7dbd34b81f (diff) | |
| download | gleam_stdlib-a3e856bcfc32382c0001bbf51c1f4e14acc21bda.tar.gz gleam_stdlib-a3e856bcfc32382c0001bbf51c1f4e14acc21bda.zip | |
better number hash
Diffstat (limited to 'src')
| -rw-r--r-- | src/persistent-hash-map.mjs | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/persistent-hash-map.mjs b/src/persistent-hash-map.mjs index 9236ec0..a1e1e3f 100644 --- a/src/persistent-hash-map.mjs +++ b/src/persistent-hash-map.mjs @@ -1,6 +1,7 @@ import { isEqual } from "./gleam.mjs"; const referenceMap = new WeakMap(); +const tempDataView = new DataView(new ArrayBuffer(8)); let referenceUID = 0; /** hash the object by reference using a weak map and incrementing uid */ @@ -29,9 +30,12 @@ function hashString(s) { } return hash; } -/** convert number to string and hash, seems to be better and faster than anything else */ +/** hash a number by converting to two integers and do some jumbling */ function hashNumber(n) { - return hashString(n.toString()); + tempDataView.setFloat64(0, n); + const i = tempDataView.getInt32(0); + const j = tempDataView.getInt32(4); + return Math.imul(0x45d9f3b, (i >> 16) ^ i) ^ j; } /** hash any js object */ function hashObject(o) { |