Function hash_generic_byte_view_array

datafusion/common/src/hash_utils.rs:372–429

(
    array: &GenericByteViewArray<T>,
    random_state: &RandomState,
    hashes_buffer: &mut [u64],
    rehash: bool,
)

/// with the new hash using `combine_hashes`
#[cfg(not(feature = "force_hash_collisions"))]
fn hash_generic_byte_view_array<T: ByteViewType>(
    array: &GenericByteViewArray<T>,
    random_state: &RandomState,
    hashes_buffer: &mut [u64],
    rehash: bool,
) {
    // instantiate the correct version based on presence of nulls and external buffers
    match (
        array.null_count() != 0,
        !array.data_buffers().is_empty(),
        rehash,
    ) {
        // no nulls or buffers ==> hash the inlined views directly
        // don't call the inner function as Rust seems better able to inline this simpler code (2-3% faster)
        (false, false, false) => {
            for (hash, &view) in hashes_buffer.iter_mut().zip(array.views().iter()) {
                *hash = view.hash_one(random_state);
            }
        }
        (false, false, true) => {
            for (hash, &view) in hashes_buffer.iter_mut().zip(array.views().iter()) {
                let mut hasher = seeded_state(*hash).build_hasher();
                view.hash_write(&mut hasher);
                *hash = hasher.finish();
            }
        }
        (false, true, false) => hash_string_view_array_inner::<T, false, true, false>(
            array,
            random_state,
            hashes_buffer,
        ),
        (false, true, true) => hash_string_view_array_inner::<T, false, true, true>(
            array,
            random_state,
            hashes_buffer,
        ),
        (true, false, false) => hash_string_view_array_inner::<T, true, false, false>(
            array,
            random_state,
            hashes_buffer,
        ),
        (true, false, true) => hash_string_view_array_inner::<T, true, false, true>(
            array,
            random_state,
            hashes_buffer,
        ),
        (true, true, false) => hash_string_view_array_inner::<T, true, true, false>(
            array,
            random_state,
            hashes_buffer,
        ),
        (true, true, true) => hash_string_view_array_inner::<T, true, true, true>(
            array,
            random_state,
            hashes_buffer,
        ),
    }
}