Trait datafusion::common::utils::proxy::RawTableAllocExt

source ·

pub trait RawTableAllocExt {
    type T;

    // Required method
    fn insert_accounted(
        &mut self,
        x: Self::T,
        hasher: impl Fn(&Self::T) -> u64,
        accounting: &mut usize,
    ) -> Bucket<Self::T>;
}

Expand description

Extension trait for hash browns RawTable to account for allocations.

Required Associated Types§

source

type T

Item type.

Required Methods§

source

fn insert_accounted( &mut self, x: Self::T, hasher: impl Fn(&Self::T) -> u64, accounting: &mut usize, ) -> Bucket<Self::T>

Insert new element into table and increase accounting by any newly allocated bytes.

Returns the bucket where the element was inserted. Note that allocation counts capacity, not size.

§Example:

let mut table = RawTable::new();
let mut allocated = 0;
let hash_fn = |x: &u32| (*x as u64) % 1000;
// pretend 0x3117 is the hash value for 1
table.insert_accounted(1, hash_fn, &mut allocated);
assert_eq!(allocated, 64);

// insert more values
for i in 0..100 { table.insert_accounted(i, hash_fn, &mut allocated); }
assert_eq!(allocated, 400);