Merge pull request 'docs(clawhdf5): document DType variants, fix unresolved doc links' (#17) from sdlc-docs/clawhdf5-types-20260514-165210 into main

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redclawsystems
2026-05-14 23:54:48 +00:00
commit 3f222f6956
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//! Apple Accelerate (AMX) / OpenBLAS-backed vector search via cblas_sgemv.
//!
//! On macOS, this links to Apple's Accelerate.framework which dispatches to the
//! AMX coprocessor for matrix/vector operations — matching numpy's performance.
//! On Linux, it links to OpenBLAS as a fallback.
//!
//! The key insight: `cblas_sgemv` computes `y = alpha * A * x + beta * y` in a
//! single call, where A is our N×D matrix of vectors and x is the query. This
//! gives us all N dot products at once, leveraging hardware-accelerated BLAS.
#[cfg(target_os = "macos")]
extern crate accelerate_src;
#[cfg(not(target_os = "macos"))]
extern crate openblas_src;
use cblas_sys::*;
/// Batch cosine similarity using cblas_sgemv (Accelerate AMX on macOS).
///
/// Computes all dot products in a single sgemv call, then divides by norms.
/// Returns top-k `(index, score)` pairs sorted by score descending.
///
/// `vectors_flat` is a contiguous `[N × dim]` f32 buffer in row-major order.
/// `norms` contains pre-computed L2 norms for each vector.
pub fn accelerate_cosine_batch(
query: &[f32],
vectors_flat: &[f32],
norms: &[f32],
tombstones: &[u8],
dim: usize,
k: usize,
) -> Vec<(usize, f32)> {
let query_norm = clawhdf5_accel::vector_norm(query);
if query_norm == 0.0 || vectors_flat.is_empty() {
return Vec::new();
}
let n = vectors_flat.len() / dim;
let all_active = tombstones.iter().all(|&t| t == 0);
if all_active {
return accelerate_cosine_all_active(query, vectors_flat, norms, dim, n, query_norm, k);
}
// With tombstones: pack active rows into a contiguous buffer
let mut active_indices: Vec<usize> = Vec::with_capacity(n);
let mut flat: Vec<f32> = Vec::with_capacity(n * dim);
for i in 0..n {
if i < tombstones.len() && tombstones[i] != 0 {
continue;
}
active_indices.push(i);
let offset = i * dim;
flat.extend_from_slice(&vectors_flat[offset..offset + dim]);
}
let active_n = active_indices.len();
if active_n == 0 {
return Vec::new();
}
let mut dot_products = vec![0.0f32; active_n];
// Single sgemv: dot_products = flat_matrix (active_n × dim) × query (dim × 1)
// SAFETY: cblas_sgemv requires valid pointers to f32 slices with the
// dimensions declared. Slices are contiguous and have the correct lengths.
unsafe {
cblas_sgemv(
CBLAS_LAYOUT::CblasRowMajor,
CBLAS_TRANSPOSE::CblasNoTrans,
active_n as i32,
dim as i32,
1.0,
flat.as_ptr(),
dim as i32,
query.as_ptr(),
1,
0.0,
dot_products.as_mut_ptr(),
1,
);
}
let mut results: Vec<(usize, f32)> = Vec::with_capacity(active_n);
for (j, &orig_idx) in active_indices.iter().enumerate() {
let denom = query_norm * norms[orig_idx];
let score = if denom == 0.0 {
0.0
} else {
dot_products[j] / denom
};
results.push((orig_idx, score));
}
results.sort_unstable_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
results.truncate(k);
results
}
/// Fast path when no tombstones — avoids the pack step entirely.
fn accelerate_cosine_all_active(
query: &[f32],
vectors_flat: &[f32],
norms: &[f32],
dim: usize,
n: usize,
query_norm: f32,
k: usize,
) -> Vec<(usize, f32)> {
let mut dot_products = vec![0.0f32; n];
// SAFETY: cblas_sgemv requires valid pointers to f32 slices with the
// dimensions declared. Slices are contiguous and have the correct lengths.
unsafe {
cblas_sgemv(
CBLAS_LAYOUT::CblasRowMajor,
CBLAS_TRANSPOSE::CblasNoTrans,
n as i32,
dim as i32,
1.0,
vectors_flat.as_ptr(),
dim as i32,
query.as_ptr(),
1,
0.0,
dot_products.as_mut_ptr(),
1,
);
}
let mut results: Vec<(usize, f32)> = dot_products
.iter()
.enumerate()
.map(|(i, &dot)| {
let denom = query_norm * norms[i];
let score = if denom == 0.0 { 0.0 } else { dot / denom };
(i, score)
})
.collect();
results.sort_unstable_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
results.truncate(k);
results
}
/// Batch cosine similarity from Vec<Vec<f32>> (convenience wrapper).
///
/// Flattens vectors and delegates to `accelerate_cosine_batch`.
pub fn accelerate_cosine_batch_vecs(
query: &[f32],
vectors: &[Vec<f32>],
norms: &[f32],
tombstones: &[u8],
k: usize,
) -> Vec<(usize, f32)> {
if vectors.is_empty() {
return Vec::new();
}
let dim = query.len();
// Build flat buffer, filtering tombstones
let mut active_indices: Vec<usize> = Vec::with_capacity(vectors.len());
let mut flat: Vec<f32> = Vec::with_capacity(vectors.len() * dim);
for (i, v) in vectors.iter().enumerate() {
if i < tombstones.len() && tombstones[i] != 0 {
continue;
}
active_indices.push(i);
flat.extend_from_slice(v);
}
let active_n = active_indices.len();
if active_n == 0 {
return Vec::new();
}
let query_norm = clawhdf5_accel::vector_norm(query);
if query_norm == 0.0 {
return Vec::new();
}
let mut dot_products = vec![0.0f32; active_n];
// SAFETY: cblas_sgemv requires valid pointers to f32 slices with the
// dimensions declared. Slices are contiguous and have the correct lengths.
unsafe {
cblas_sgemv(
CBLAS_LAYOUT::CblasRowMajor,
CBLAS_TRANSPOSE::CblasNoTrans,
active_n as i32,
dim as i32,
1.0,
flat.as_ptr(),
dim as i32,
query.as_ptr(),
1,
0.0,
dot_products.as_mut_ptr(),
1,
);
}
let mut results: Vec<(usize, f32)> = Vec::with_capacity(active_n);
for (j, &orig_idx) in active_indices.iter().enumerate() {
let denom = query_norm * norms[orig_idx];
let score = if denom == 0.0 {
0.0
} else {
dot_products[j] / denom
};
results.push((orig_idx, score));
}
results.sort_unstable_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
results.truncate(k);
results
}
/// Compute L2 norms for all vectors in a flat buffer using cblas_snrm2.
///
/// Returns a Vec of norms, one per vector.
pub fn accelerate_batch_norms(vectors_flat: &[f32], dim: usize) -> Vec<f32> {
if dim == 0 || vectors_flat.is_empty() {
return Vec::new();
}
let n = vectors_flat.len() / dim;
let mut norms = Vec::with_capacity(n);
for i in 0..n {
let offset = i * dim;
// SAFETY: cblas_snrm2 requires a valid pointer to f32 slice of length dim.
let norm = unsafe { cblas_snrm2(dim as i32, vectors_flat[offset..].as_ptr(), 1) };
norms.push(norm);
}
norms
}
// ---------------------------------------------------------------------------
// vDSP-based dot product (macOS only) — may be faster than sgemv for small N
// ---------------------------------------------------------------------------
#[cfg(target_os = "macos")]
extern "C" {
fn vDSP_dotpr(__A: *const f32, __IA: i32, __B: *const f32, __IB: i32, __C: *mut f32, __N: u32);
}
/// Batch cosine similarity using vDSP_dotpr (macOS only).
///
/// Calls vDSP_dotpr per vector — each call is hardware-accelerated but
/// there's per-call overhead. May beat sgemv for small N where the matrix
/// setup cost of sgemv dominates.
#[cfg(target_os = "macos")]
pub fn vdsp_cosine_batch(
query: &[f32],
vectors_flat: &[f32],
norms: &[f32],
tombstones: &[u8],
dim: usize,
k: usize,
) -> Vec<(usize, f32)> {
let query_norm = clawhdf5_accel::vector_norm(query);
if query_norm == 0.0 || vectors_flat.is_empty() {
return Vec::new();
}
let n = vectors_flat.len() / dim;
let mut results: Vec<(usize, f32)> = Vec::with_capacity(n);
for i in 0..n {
if i < tombstones.len() && tombstones[i] != 0 {
continue;
}
let offset = i * dim;
let mut dot: f32 = 0.0;
// SAFETY: vDSP_dotpr requires valid f32 pointers with length dim. Offsets are
// within the vectors_flat slice bounds.
unsafe {
vDSP_dotpr(
vectors_flat[offset..].as_ptr(),
1,
query.as_ptr(),
1,
&mut dot,
dim as u32,
);
}
let denom = query_norm * norms[i];
let score = if denom == 0.0 { 0.0 } else { dot / denom };
results.push((i, score));
}
results.sort_unstable_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
results.truncate(k);
results
}
#[cfg(test)]
mod tests {
use super::*;
fn make_vectors_flat(n: usize, dim: usize, seed: u32) -> Vec<f32> {
let mut s = seed;
let mut next = || -> f32 {
s = s.wrapping_mul(1103515245).wrapping_add(12345);
((s >> 16) as f32) / 65536.0 - 0.5
};
(0..n * dim).map(|_| next()).collect()
}
fn make_vectors_vecs(n: usize, dim: usize, seed: u32) -> Vec<Vec<f32>> {
let flat = make_vectors_flat(n, dim, seed);
flat.chunks(dim).map(|c| c.to_vec()).collect()
}
fn compute_norms_flat(flat: &[f32], dim: usize) -> Vec<f32> {
flat.chunks(dim)
.map(|v| clawhdf5_accel::vector_norm(v))
.collect()
}
// --- Test 1: Accelerate results match SIMD within f32 epsilon ---
#[test]
fn accelerate_matches_simd_scores() {
let dim = 384;
let n = 500;
let vecs = make_vectors_vecs(n, dim, 42);
let flat: Vec<f32> = vecs.iter().flat_map(|v| v.iter().copied()).collect();
let norms = compute_norms_flat(&flat, dim);
let tombstones = vec![0u8; n];
let query = vecs[0].clone();
let accel_results = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, n);
let simd_results = crate::vector_search::cosine_similarity_batch_prenorm(
&query,
&vecs,
&norms,
&tombstones,
);
assert_eq!(accel_results.len(), simd_results.len());
for (a, s) in accel_results.iter().zip(&simd_results) {
assert_eq!(a.0, s.0, "index mismatch");
assert!(
(a.1 - s.1).abs() < 1e-4,
"score mismatch at idx {}: accel={} vs simd={}",
a.0,
a.1,
s.1,
);
}
}
// --- Test 2: Accelerate ranking matches SIMD ranking ---
#[test]
fn accelerate_ranking_matches_simd() {
let dim = 128;
let n = 200;
let vecs = make_vectors_vecs(n, dim, 77);
let flat: Vec<f32> = vecs.iter().flat_map(|v| v.iter().copied()).collect();
let norms = compute_norms_flat(&flat, dim);
let tombstones = vec![0u8; n];
let query = vecs[5].clone();
let accel_top10 = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, 10);
let simd_all = crate::vector_search::cosine_similarity_batch_prenorm(
&query,
&vecs,
&norms,
&tombstones,
);
let simd_top10 = crate::vector_search::top_k(simd_all, 10);
let accel_ids: Vec<usize> = accel_top10.iter().map(|r| r.0).collect();
let simd_ids: Vec<usize> = simd_top10.iter().map(|r| r.0).collect();
assert_eq!(accel_ids, simd_ids, "top-10 ranking should match");
}
// --- Test 3: Vec<Vec> wrapper matches flat variant ---
#[test]
fn accelerate_vecs_matches_flat() {
let dim = 64;
let n = 200;
let vecs = make_vectors_vecs(n, dim, 42);
let flat: Vec<f32> = vecs.iter().flat_map(|v| v.iter().copied()).collect();
let norms = compute_norms_flat(&flat, dim);
let tombstones = vec![0u8; n];
let query = vecs[3].clone();
let flat_results = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, 10);
let vec_results = accelerate_cosine_batch_vecs(&query, &vecs, &norms, &tombstones, 10);
assert_eq!(flat_results.len(), vec_results.len());
for (f, v) in flat_results.iter().zip(&vec_results) {
assert_eq!(f.0, v.0);
assert!((f.1 - v.1).abs() < 1e-5);
}
}
// --- Test 4: Tombstones properly excluded ---
#[test]
fn accelerate_excludes_tombstones() {
let dim = 3;
let flat = vec![
1.0, 0.0, 0.0, // idx 0: identical to query
0.0, 1.0, 0.0, // idx 1: tombstoned
0.5, 0.5, 0.0, // idx 2: partial match
];
let norms = compute_norms_flat(&flat, dim);
let tombstones = vec![0, 1, 0];
let query = vec![1.0, 0.0, 0.0];
let results = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, 10);
assert_eq!(results.len(), 2);
assert!(results.iter().all(|(idx, _)| *idx != 1));
assert_eq!(results[0].0, 0);
}
// --- Test 5: Pre-computed norms via accelerate_batch_norms ---
#[test]
fn accelerate_batch_norms_match_individual() {
let dim = 384;
let n = 100;
let flat = make_vectors_flat(n, dim, 42);
let batch_norms = accelerate_batch_norms(&flat, dim);
let individual_norms = compute_norms_flat(&flat, dim);
assert_eq!(batch_norms.len(), individual_norms.len());
for (b, i) in batch_norms.iter().zip(&individual_norms) {
assert!(
(b - i).abs() < 1e-5,
"norm mismatch: batch={b} vs individual={i}"
);
}
}
// --- Test 6: Empty vectors returns empty ---
#[test]
fn accelerate_empty_vectors() {
let query = vec![1.0, 0.0, 0.0];
let results = accelerate_cosine_batch(&query, &[], &[], &[], 3, 10);
assert!(results.is_empty());
}
// --- Test 7: Zero query returns empty ---
#[test]
fn accelerate_zero_query() {
let flat = vec![1.0, 0.0, 0.0];
let norms = compute_norms_flat(&flat, 3);
let query = vec![0.0, 0.0, 0.0];
let results = accelerate_cosine_batch(&query, &flat, &norms, &[0], 3, 10);
assert!(results.is_empty());
}
// --- Test 8: Identical vector has score ~1.0 ---
#[test]
fn accelerate_identical_score_one() {
let query = vec![1.0, 2.0, 3.0, 4.0];
let flat = query.clone();
let norms = compute_norms_flat(&flat, 4);
let results = accelerate_cosine_batch(&query, &flat, &norms, &[0], 4, 1);
assert_eq!(results.len(), 1);
assert!(
(results[0].1 - 1.0).abs() < 1e-5,
"expected ~1.0, got {}",
results[0].1
);
}
// --- Test 9: Orthogonal vectors have score ~0 ---
#[test]
fn accelerate_orthogonal_score_zero() {
let query = vec![1.0, 0.0, 0.0];
let flat = vec![0.0, 1.0, 0.0];
let norms = compute_norms_flat(&flat, 3);
let results = accelerate_cosine_batch(&query, &flat, &norms, &[0], 3, 1);
assert_eq!(results.len(), 1);
assert!(
results[0].1.abs() < 1e-5,
"expected ~0, got {}",
results[0].1
);
}
// --- Test 10: Negative correlation detected ---
#[test]
fn accelerate_negative_correlation() {
let query = vec![1.0, 0.0];
let flat = vec![-1.0, 0.0];
let norms = compute_norms_flat(&flat, 2);
let results = accelerate_cosine_batch(&query, &flat, &norms, &[0], 2, 1);
assert_eq!(results.len(), 1);
assert!(
(results[0].1 - (-1.0)).abs() < 1e-5,
"expected ~-1.0, got {}",
results[0].1
);
}
// --- Test 11: All tombstoned returns empty ---
#[test]
fn accelerate_all_tombstoned() {
let flat = vec![1.0, 0.0, 0.0, 0.0, 1.0, 0.0];
let norms = compute_norms_flat(&flat, 3);
let query = vec![1.0, 0.0, 0.0];
let results = accelerate_cosine_batch(&query, &flat, &norms, &[1, 1], 3, 10);
assert!(results.is_empty());
}
// --- Test 12: Top-k truncation works ---
#[test]
fn accelerate_top_k_truncation() {
let dim = 32;
let n = 100;
let flat = make_vectors_flat(n, dim, 42);
let norms = compute_norms_flat(&flat, dim);
let tombstones = vec![0u8; n];
let query: Vec<f32> = flat[..dim].to_vec();
let results = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, 5);
assert_eq!(results.len(), 5);
for w in results.windows(2) {
assert!(w[0].1 >= w[1].1);
}
}
// --- Test 13: Large-scale accelerate matches SIMD (1000 vectors, 384 dims) ---
#[test]
fn accelerate_large_scale_matches_simd() {
let dim = 384;
let n = 1000;
let vecs = make_vectors_vecs(n, dim, 42);
let flat: Vec<f32> = vecs.iter().flat_map(|v| v.iter().copied()).collect();
let norms = compute_norms_flat(&flat, dim);
let mut tombstones = vec![0u8; n];
for i in (0..n).step_by(7) {
tombstones[i] = 1;
}
let query = vecs[1].clone();
let accel_top20 = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, 20);
let simd_all = crate::vector_search::cosine_similarity_batch_prenorm(
&query,
&vecs,
&norms,
&tombstones,
);
let simd_top20 = crate::vector_search::top_k(simd_all, 20);
assert_eq!(accel_top20.len(), simd_top20.len());
for (a, s) in accel_top20.iter().zip(&simd_top20) {
assert_eq!(a.0, s.0, "index mismatch in top-20");
assert!(
(a.1 - s.1).abs() < 1e-4,
"score mismatch: accel={} vs simd={}",
a.1,
s.1,
);
}
}
// --- Test 14: Batch norms empty ---
#[test]
fn accelerate_batch_norms_empty() {
let norms = accelerate_batch_norms(&[], 4);
assert!(norms.is_empty());
}
// --- Test 15: vDSP cosine matches sgemv (macOS only) ---
#[cfg(target_os = "macos")]
#[test]
fn vdsp_matches_sgemv() {
let dim = 384;
let n = 500;
let flat = make_vectors_flat(n, dim, 42);
let norms = compute_norms_flat(&flat, dim);
let tombstones = vec![0u8; n];
let query: Vec<f32> = flat[..dim].to_vec();
let sgemv_results = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, 10);
let vdsp_results = vdsp_cosine_batch(&query, &flat, &norms, &tombstones, dim, 10);
assert_eq!(sgemv_results.len(), vdsp_results.len());
for (s, v) in sgemv_results.iter().zip(&vdsp_results) {
assert_eq!(s.0, v.0, "index mismatch");
assert!(
(s.1 - v.1).abs() < 1e-5,
"score mismatch: sgemv={} vs vdsp={}",
s.1,
v.1,
);
}
}
// --- Test 16: Performance - 10K should complete quickly ---
#[test]
fn accelerate_performance_10k() {
let dim = 384;
let n = 10_000;
let flat = make_vectors_flat(n, dim, 42);
let norms = compute_norms_flat(&flat, dim);
let tombstones = vec![0u8; n];
let query: Vec<f32> = flat[..dim].to_vec();
let start = std::time::Instant::now();
let results = accelerate_cosine_batch(&query, &flat, &norms, &tombstones, dim, 10);
let elapsed = start.elapsed();
assert_eq!(results.len(), 10);
assert!(
elapsed.as_millis() < 500,
"Accelerate 10K took {}ms, expected < 500ms",
elapsed.as_millis()
);
}
}