snarkvm-algorithms 0.14.6

// Copyright (C) 2019-2023 Aleo Systems Inc.
// This file is part of the snarkVM library.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
// http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::collections::BTreeMap;

use crate::{
    fft::DensePolynomial,
    polycommit::sonic_pc::{LabeledPolynomial, PolynomialInfo, PolynomialLabel},
    snark::marlin::{
        ahp::{verifier, AHPError, AHPForR1CS},
        prover,
        MarlinMode,
    },
};

use itertools::Itertools;
use rand_core::RngCore;
use rayon::prelude::*;
use snarkvm_fields::PrimeField;

impl<F: PrimeField, MM: MarlinMode> AHPForR1CS<F, MM> {
    /// Output the number of oracles sent by the prover in the third round.
    pub fn num_fourth_round_oracles() -> usize {
        1
    }

    /// Output the fourth round message and the next state.
    pub fn prover_fourth_round<R: RngCore>(
        verifier_message: verifier::ThirdMessage<F>,
        state: prover::State<'_, F, MM>,
        _r: &mut R,
    ) -> Result<prover::FourthOracles<F>, AHPError> {
        let lhs_sum: DensePolynomial<F> = verifier_message
            .into_iter()
            .zip_eq(state.lhs_polys_into_iter())
            .par_bridge()
            .map(|(delta, mut lhs)| {
                lhs *= delta;
                lhs
            })
            .reduce(
                || DensePolynomial::zero(),
                |mut a, mut b| {
                    a += &std::mem::take(&mut b);
                    a
                },
            );
        let h_2 = LabeledPolynomial::new("h_2".into(), lhs_sum, None, None);
        let oracles = prover::FourthOracles { h_2 };
        assert!(oracles.matches_info(&Self::fourth_round_polynomial_info()));
        Ok(oracles)
    }

    /// Output the degree bounds of oracles in the third round.
    pub fn fourth_round_polynomial_info() -> BTreeMap<PolynomialLabel, PolynomialInfo> {
        [("h_2".into(), PolynomialInfo::new("h_2".into(), None, None))].into()
    }
}