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usize

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This commit is contained in:
Lev Kokotov
2022-02-08 11:14:20 -08:00
parent 39a9dff26b
commit 5f9f2c21fc
1 changed files with 5 additions and 2 deletions
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7
src/sharding.rs
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@@ -27,11 +27,11 @@ impl Sharder {
/// to put the row in when using HASH(column) partitioning. /// to put the row in when using HASH(column) partitioning.
/// Source: https://github.com/postgres/postgres/blob/27b77ecf9f4d5be211900eda54d8155ada50d696/src/common/hashfn.c#L631 /// Source: https://github.com/postgres/postgres/blob/27b77ecf9f4d5be211900eda54d8155ada50d696/src/common/hashfn.c#L631
/// Supports only 1 bigint at the moment, but we can add more later. /// Supports only 1 bigint at the moment, but we can add more later.
pub fn pg_bigint_hash(&self, key: i64) -> u64 { pub fn pg_bigint_hash(&self, key: i64) -> usize {
let mut lohalf = key as u32; let mut lohalf = key as u32;
let hihalf = (key >> 32) as u32; let hihalf = (key >> 32) as u32;
lohalf ^= if key >= 0 { hihalf } else { !hihalf }; lohalf ^= if key >= 0 { hihalf } else { !hihalf };
Self::combine(0, Self::pg_u32_hash(lohalf)) % self.shards as u64 Self::combine(0, Self::pg_u32_hash(lohalf)) as usize % self.shards as usize
} }
#[inline] #[inline]
@@ -125,6 +125,9 @@ mod test {
assert_eq!(shard, 1); assert_eq!(shard, 1);
} }
// See tests/sharding/setup.sql
// The output of those SELECT statements will match this test,
// confirming that we implemented Postgres BIGINT hashing correctly.
#[test] #[test]
fn test_pg_bigint_hash() { fn test_pg_bigint_hash() {
let sharder = Sharder::new(5); let sharder = Sharder::new(5);