PiPNN 3/6: add core graph construction - #1290

diskann-pipnn/src/partitioning.rs:604

• size_of::<f32>() is used without being in scope (no use std::mem::size_of; and not qualified), so this function won’t compile as written.

fn assignment_stripe_rows(leaders: usize) -> usize {
    (ASSIGNMENT_CACHE_TARGET_BYTES / (leaders.max(1) * size_of::<f32>()))
        .clamp(MIN_ASSIGNMENT_STRIPE_ROWS, MAX_ASSIGNMENT_STRIPE_ROWS)
}

diskann-pipnn/src/partitioning.rs:637

• size_of is used without being in scope (std::mem::size_of), which will not compile. Qualify the call or import it.

fn assignment_stripe_rows(leaders: usize) -> usize {
    (ASSIGNMENT_CACHE_TARGET_BYTES / (leaders.max(1) * size_of::<f32>()))
        .clamp(MIN_ASSIGNMENT_STRIPE_ROWS, MAX_ASSIGNMENT_STRIPE_ROWS)
}

diskann-pipnn/src/partitioning.rs:19

• Norm is imported but never used in this module, which will trip unused_imports warnings (and can become CI failures under -D warnings). Remove it from the import list.

use diskann::{utils::VectorRepr, ANNError, ANNResult};
use diskann_linalg::Transpose;
use diskann_utils::views::MatrixView;
use diskann_vector::{distance::Metric, norm::FastL2NormSquared, Norm};
use rand::{prelude::IndexedRandom, SeedableRng};
use rayon::prelude::*;

diskann-pipnn/src/partitioning.rs:390

• gather_rows uses TypeId::of::<T>(), which implicitly requires T: 'static. Making that bound explicit here avoids surprising/indirect trait-bound errors later and matches the public build_graph boundary (which already requires 'static).

fn gather_rows<T>(data: MatrixView<'_, T>, indices: &[u32], output: &mut [f32]) -> ANNResult<()>
where
    T: VectorRepr,

diskann-pipnn/src/partitioning.rs:641

• size_of::<f32>() is used without being imported or qualified, which will fail to compile. Qualify it with std::mem::size_of (or add an explicit import).

    let rows = ASSIGNMENT_CACHE_TARGET_BYTES / (leaders.max(1) * size_of::<f32>());

diskann-pipnn/src/leaf_build.rs:222

• build_leaf is executed from a Rayon parallel context (via build_leaf_candidates), so it should also explicitly require T: Send + Sync to reflect the actual thread-safety requirement.

where
    T: VectorRepr + 'static,
{

diskann-pipnn/src/leaf_build/tests.rs:154

• assert_source_type forwards T into the parallel leaf build path, so it should also include Send + Sync bounds to match the production requirements.

fn assert_source_type<T>(data: &[T])
where
    T: diskann::utils::VectorRepr + 'static,
{

diskann-pipnn/src/leaf_build.rs:193

• build_leaf_candidates uses Rayon parallel iteration over data, so T must be Send + Sync. Making this explicit in the signature avoids confusing trait-bound errors at call sites and documents the thread-safety requirement.

This issue also appears on line 220 of the same file.

where
    T: VectorRepr + 'static,
{

diskann-pipnn/src/leaf_build/tests.rs:35

• This test helper calls build_leaf_candidates, which (via Rayon) requires T: Send + Sync. Add the bounds here so the test continues to compile once the production signature is tightened.

This issue also appears on line 151 of the same file.

where
    T: diskann::utils::VectorRepr + 'static,
{