Skip to content

Use std OnceLock to avoid wasted CPU time #637

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jtraglia merged 2 commits into from
Mar 9, 2026
+18 −50
Merged

Use std OnceLock to avoid wasted CPU time #637

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
96d7bf6
Use std OnceLock to avoid wasted CPU time
DaniPopes Mar 9, 2026
94f89a2
Simplify cache creation
DaniPopes Mar 9, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
68 changes: 18 additions & 50 deletions bindings/rust/src/ethereum_kzg_settings/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,13 @@
use crate::KzgSettings;
use alloc::{boxed::Box, sync::Arc};
use once_cell::race::OnceBox;
use alloc::sync::Arc;

#[cfg(not(feature = "std"))]
use once_cell::race::OnceBox as OnceLock;
#[cfg(feature = "std")]
use std::sync::OnceLock;

#[cfg(feature = "std")]
use once_cell as _;

/// Default G1 monomial bytes.
const ETH_G1_MONOMIAL_POINTS: &[u8] = include_bytes!("./g1_monomial_bytes.bin");
Expand All @@ -9,31 +16,6 @@ const ETH_G1_LAGRANGE_POINTS: &[u8] = include_bytes!("./g1_lagrange_bytes.bin");
/// Default G2 monomial bytes.
const ETH_G2_MONOMIAL_POINTS: &[u8] = include_bytes!("./g2_monomial_bytes.bin");

macro_rules! create_cache {
($name:ident) => {
static $name: OnceBox<Arc<KzgSettings>> = OnceBox::new();
};
}

// We use separate OnceBox instances for each precompute value.
// This avoids the need for any unsafe code or mutexes.
create_cache!(CACHE_0);
create_cache!(CACHE_1);
create_cache!(CACHE_2);
create_cache!(CACHE_3);
create_cache!(CACHE_4);
create_cache!(CACHE_5);
create_cache!(CACHE_6);
create_cache!(CACHE_7);
create_cache!(CACHE_8);
create_cache!(CACHE_9);
create_cache!(CACHE_10);
create_cache!(CACHE_11);
create_cache!(CACHE_12);
create_cache!(CACHE_13);
create_cache!(CACHE_14);
create_cache!(CACHE_15);

/// Returns default Ethereum mainnet KZG settings.
///
/// If you need a cloneable settings use `ethereum_kzg_settings_arc` instead.
Expand All @@ -53,37 +35,23 @@ pub fn ethereum_kzg_settings_arc(precompute: u64) -> Arc<KzgSettings> {
}

fn ethereum_kzg_settings_inner(precompute: u64) -> &'static Arc<KzgSettings> {
let cache_box = match precompute {
0 => &CACHE_0,
1 => &CACHE_1,
2 => &CACHE_2,
3 => &CACHE_3,
4 => &CACHE_4,
5 => &CACHE_5,
6 => &CACHE_6,
7 => &CACHE_7,
8 => &CACHE_8,
9 => &CACHE_9,
10 => &CACHE_10,
11 => &CACHE_11,
12 => &CACHE_12,
13 => &CACHE_13,
14 => &CACHE_14,
15 => &CACHE_15,
_ => panic!(
"Unsupported precompute value: {precompute}. Only values 0-15 (inclusive) are supported."
),
};
static CACHES: [OnceLock<Arc<KzgSettings>>; 16] = [const { OnceLock::new() }; 16];

assert!(
precompute <= 15,
"Unsupported precompute value: {precompute}. Only values 0-15 (inclusive) are supported."
);

cache_box.get_or_init(|| {
CACHES[precompute as usize].get_or_init(|| {
let settings = KzgSettings::load_trusted_setup(
ETH_G1_MONOMIAL_POINTS,
ETH_G1_LAGRANGE_POINTS,
ETH_G2_MONOMIAL_POINTS,
precompute,
)
.expect("failed to load default trusted setup");
Box::new(Arc::new(settings))
#[allow(clippy::useless_conversion)] // `std`: no-op, `not(std)`: allocates into a `Box`.
Arc::new(settings).into()
})
}

Expand Down
Loading