Struct massa_models::prehash::HashMapper

pub struct HashMapper<T: PreHashed> {
    source: PhantomData<T>,
    hash: u64,
}

A Hasher for PreHashed keys that is faster because it avoids re-hashing hashes but simply truncates them. Note: when truncating, it takes the last 8 bytes of the key instead of the first 8 bytes. This is done to circumvent biases induced by first-byte manipulations in addresses related to the thread assignment process

Fields

source: PhantomData<T>

hash: u64

Trait Implementations

impl<T: PreHashed> Default for HashMapper<T>

Default implementation for HashMapper (zero hash)

fn default() -> Self

Returns the “default value” for a type.

impl<T: PreHashed> Hasher for HashMapper<T>

Hasher implementation for HashMapper

fn finish(&self) -> u64

finish the hashing process and return the truncated u64 hash

fn write(&mut self, bytes: &[u8])

write the bytes of a PreHashed key into the HashMapper Panics if bytes.len() is strictly lower than 8 Note: the truncated u64 is completely overwritten by the last 8 items of “bytes” at every call

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.

fn write_length_prefix(&mut self, len: usize)

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)

Writes a length prefix into this hasher, as part of being prefix-free.

fn write_str(&mut self, s: &str)

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)

Writes a single str into this hasher.