refactor(starknet_os): polynomial_coefficients_to_kzg_commitment directly outputs felts

Signed-off-by: Dori Medini <dori@starkware.co>

Author: dorimedini-starkware

crates/starknet_os/src/hints/hint_implementation/kzg/implementation.rs

@@ -41,7 +41,7 @@ pub(crate) fn store_da_segment<S: StateReader>(
         }
     })?;
 
-    let kzg_commitments_bigints: Vec<(BigInt, BigInt)> = da_segment
+    let kzg_commitments: Vec<(Felt, Felt)> = da_segment
         .chunks(blob_length)
         .enumerate()
         .map(|(chunk_id, chunk)| {
@@ -51,10 +51,6 @@ pub(crate) fn store_da_segment<S: StateReader>(
         })
         .collect::<Result<_, _>>()?;
     log::debug!("Done computing KZG commitments.");
-    let kzg_commitments: Vec<(Felt, Felt)> = kzg_commitments_bigints
-        .into_iter()
-        .map(|bigint_pair| (bigint_pair.0.into(), bigint_pair.1.into()))
-        .collect();
 
     hint_processor.set_da_segment(da_segment)?;
 

crates/starknet_os/src/hints/hint_implementation/kzg/test.rs

@@ -4,6 +4,7 @@ use c_kzg::KzgCommitment;
 use num_bigint::BigInt;
 use num_traits::{Num, One, Zero};
 use rstest::rstest;
+use starknet_types_core::felt::Felt;
 
 use crate::hints::hint_implementation::kzg::utils::{fft, split_commitment, BLS_PRIME};
 
@@ -80,8 +81,8 @@ fn test_fft(#[values(true, false)] bit_reversed: bool) {
         16,
     ).unwrap(),
     (
-        BigInt::from_str_radix("590b91a225b1bf7fa5877ec546d090e0059f019c74675362", 16).unwrap(),
-        BigInt::from_str_radix("b7a71dc9d8e15ea474a69c0531e720cf5474b189ac9afc81", 16).unwrap(),
+        Felt::from_hex_unchecked("590b91a225b1bf7fa5877ec546d090e0059f019c74675362"),
+        Felt::from_hex_unchecked("b7a71dc9d8e15ea474a69c0531e720cf5474b189ac9afc81"),
     )
 )]
 #[case(
@@ -90,13 +91,13 @@ fn test_fft(#[values(true, false)] bit_reversed: bool) {
         16,
     ).unwrap(),
     (
-        BigInt::from_str_radix("51732ecbaa75842afd3d8860d40b3e8eeea433bce18b5c8", 16).unwrap(),
-        BigInt::from_str_radix("a797c1973c99961e357246ee81bde0acbdd27e801d186ccb", 16).unwrap(),
+        Felt::from_hex_unchecked("51732ecbaa75842afd3d8860d40b3e8eeea433bce18b5c8"),
+        Felt::from_hex_unchecked("a797c1973c99961e357246ee81bde0acbdd27e801d186ccb"),
     )
 )]
 fn test_split_commitment_function(
     #[case] commitment: BigInt,
-    #[case] expected_output: (BigInt, BigInt),
+    #[case] expected_output: (Felt, Felt),
 ) {
     let commitment = KzgCommitment::from_bytes(&commitment.to_bytes_be().1).unwrap();
     assert_eq!(split_commitment(&commitment).unwrap(), expected_output);

crates/starknet_os/src/hints/hint_implementation/kzg/utils.rs

@@ -4,9 +4,10 @@ use std::sync::LazyLock;
 
 use blockifier::utils::usize_from_u32;
 use c_kzg::{Blob, KzgCommitment, KzgSettings, BYTES_PER_FIELD_ELEMENT};
-use num_bigint::{BigInt, ParseBigIntError, Sign};
+use num_bigint::{BigInt, ParseBigIntError};
 use num_traits::{Num, One, Zero};
 use starknet_infra_utils::compile_time_cargo_manifest_dir;
+use starknet_types_core::felt::Felt;
 
 const BLOB_SUBGROUP_GENERATOR: &str =
     "39033254847818212395286706435128746857159659164139250548781411570340225835782";
@@ -155,14 +156,14 @@ pub(crate) fn fft(
     Ok(values)
 }
 
-pub(crate) fn split_commitment(commitment: &KzgCommitment) -> Result<(BigInt, BigInt), FftError> {
+pub(crate) fn split_commitment(commitment: &KzgCommitment) -> Result<(Felt, Felt), FftError> {
     let commitment_bytes: [u8; COMMITMENT_BYTES_LENGTH] = *commitment.to_bytes().as_ref();
 
     // Split the number.
     let low = &commitment_bytes[COMMITMENT_BYTES_MIDPOINT..];
     let high = &commitment_bytes[..COMMITMENT_BYTES_MIDPOINT];
 
-    Ok((BigInt::from_bytes_be(Sign::Plus, low), BigInt::from_bytes_be(Sign::Plus, high)))
+    Ok((Felt::from_bytes_be_slice(low), Felt::from_bytes_be_slice(high)))
 }
 
 fn polynomial_coefficients_to_blob(coefficients: Vec<BigInt>) -> Result<Vec<u8>, FftError> {
@@ -186,7 +187,7 @@ fn polynomial_coefficients_to_blob(coefficients: Vec<BigInt>) -> Result<Vec<u8>,
 
 pub(crate) fn polynomial_coefficients_to_kzg_commitment(
     coefficients: Vec<BigInt>,
-) -> Result<(BigInt, BigInt), FftError> {
+) -> Result<(Felt, Felt), FftError> {
     let blob = polynomial_coefficients_to_blob(coefficients)?;
     let commitment_bytes = blob_to_kzg_commitment(&Blob::from_bytes(&blob)?)?;
     split_commitment(&commitment_bytes)