From 19c1b20063d1a5eaef78d263844acdfd58f12200 Mon Sep 17 00:00:00 2001
From: therealyingtong <yingtong@z.cash>
Date: Tue, 1 Dec 2020 17:11:47 +0800
Subject: [PATCH] Add lookup::verifier methods

---
 src/plonk/lookup/verifier.rs | 159 ++++++++++++++++++++++++++++++++++-
 1 file changed, 156 insertions(+), 3 deletions(-)

diff --git a/src/plonk/lookup/verifier.rs b/src/plonk/lookup/verifier.rs
index 594644e..c22ede1 100644
--- a/src/plonk/lookup/verifier.rs
+++ b/src/plonk/lookup/verifier.rs
@@ -1,4 +1,157 @@
-use super::Proof;
-use crate::arithmetic::CurveAffine;
+use std::iter;
 
-impl<C: CurveAffine> Proof<C> {}
+use super::super::circuit::Any;
+use super::{Argument, Proof};
+use crate::{
+    arithmetic::CurveAffine,
+    plonk::{ChallengeBeta, ChallengeGamma, ChallengeTheta, ChallengeX, Error, VerifyingKey},
+    poly::{multiopen::VerifierQuery, Rotation},
+    transcript::{Hasher, Transcript},
+};
+use ff::Field;
+
+impl<C: CurveAffine> Proof<C> {
+    pub(crate) fn absorb_permuted_commitments<
+        HBase: Hasher<C::Base>,
+        HScalar: Hasher<C::Scalar>,
+    >(
+        &self,
+        transcript: &mut Transcript<C, HBase, HScalar>,
+    ) -> Result<(), Error> {
+        transcript
+            .absorb_point(&self.permuted_input_commitment)
+            .map_err(|_| Error::TranscriptError)?;
+        transcript
+            .absorb_point(&self.permuted_table_commitment)
+            .map_err(|_| Error::TranscriptError)?;
+        Ok(())
+    }
+
+    pub(crate) fn absorb_product_commitment<HBase: Hasher<C::Base>, HScalar: Hasher<C::Scalar>>(
+        &self,
+        transcript: &mut Transcript<C, HBase, HScalar>,
+    ) -> Result<(), Error> {
+        transcript
+            .absorb_point(&self.product_commitment)
+            .map_err(|_| Error::TranscriptError)?;
+        Ok(())
+    }
+
+    pub(in crate::plonk) fn expressions<'a>(
+        &'a self,
+        vk: &'a VerifyingKey<C>,
+        l_0: C::Scalar,
+        argument: Argument,
+        theta: ChallengeTheta<C::Scalar>,
+        beta: ChallengeBeta<C::Scalar>,
+        gamma: ChallengeGamma<C::Scalar>,
+        advice_evals: &[C::Scalar],
+        fixed_evals: &[C::Scalar],
+        aux_evals: &[C::Scalar],
+    ) -> impl Iterator<Item = C::Scalar> + 'a {
+        let product_expression = || {
+            // z'(X) (a'(X) + \beta) (s'(X) + \gamma)
+            // - z'(\omega^{-1} X) (a_1(X) + \theta a_2(X) + ... + \beta) (s_1(X) + \theta s_2(X) + ... + \gamma)
+            let left = self.product_eval
+                * &(self.permuted_input_eval + &beta)
+                * &(self.permuted_table_eval + &gamma);
+
+            let mut right = self.product_inv_eval;
+            let mut input_term = C::Scalar::zero();
+            for &input in argument.input_columns.iter() {
+                let index = vk.cs.get_any_query_index(input, 0);
+                let eval = match input.column_type() {
+                    Any::Advice => advice_evals[index],
+                    Any::Fixed => fixed_evals[index],
+                    Any::Aux => aux_evals[index],
+                };
+                input_term *= &theta;
+                input_term += &eval;
+            }
+            input_term += &beta;
+
+            let mut table_term = C::Scalar::zero();
+            for &table in argument.table_columns.iter() {
+                let index = vk.cs.get_any_query_index(table, 0);
+                let eval = match table.column_type() {
+                    Any::Advice => advice_evals[index],
+                    Any::Fixed => fixed_evals[index],
+                    Any::Aux => aux_evals[index],
+                };
+                table_term *= &theta;
+                table_term += &eval;
+            }
+            table_term += &gamma;
+
+            right *= &(input_term * &table_term);
+            left - &right
+        };
+
+        std::iter::empty()
+            .chain(
+                // l_0(X) * (1 - z'(X)) = 0
+                Some(l_0 * &(C::Scalar::one() - &self.product_eval)),
+            )
+            .chain(
+                // z'(X) (a'(X) + \beta) (s'(X) + \gamma)
+                // - z'(\omega^{-1} X) (a_1(X) + \theta a_2(X) + ... + \beta) (s_1(X) + \theta s_2(X) + ... + \gamma)
+                Some(product_expression()),
+            )
+            .chain(Some(
+                l_0 * &(self.permuted_input_eval - &self.permuted_table_eval),
+            ))
+            .chain(Some(
+                (self.permuted_input_eval - &self.permuted_table_eval)
+                    * &(self.permuted_input_eval - &self.permuted_input_inv_eval),
+            ))
+    }
+
+    pub(crate) fn evals(&self) -> impl Iterator<Item = C::Scalar> {
+        iter::empty()
+            .chain(Some(self.product_eval))
+            .chain(Some(self.product_inv_eval))
+            .chain(Some(self.permuted_input_eval))
+            .chain(Some(self.permuted_input_inv_eval))
+            .chain(Some(self.permuted_table_eval))
+    }
+
+    pub(in crate::plonk) fn queries<'a>(
+        &'a self,
+        vk: &'a VerifyingKey<C>,
+        x: ChallengeX<C::Scalar>,
+    ) -> impl Iterator<Item = VerifierQuery<'a, C>> + Clone {
+        let x_inv = vk.domain.rotate_omega(*x, Rotation(-1));
+
+        iter::empty()
+            // Open lookup product commitments at x
+            .chain(Some(VerifierQuery {
+                point: *x,
+                commitment: &self.product_commitment,
+                eval: self.product_eval,
+            }))
+            // Open lookup input commitments at x
+            .chain(Some(VerifierQuery {
+                point: *x,
+                commitment: &self.permuted_input_commitment,
+                eval: self.permuted_input_eval,
+            }))
+            // Open lookup table commitments at x
+            .chain(Some(VerifierQuery {
+                point: *x,
+                commitment: &self.permuted_table_commitment,
+                eval: self.permuted_table_eval,
+            }))
+            // Open lookup input commitments at \omega^{-1} x
+            .chain(Some(VerifierQuery {
+                point: x_inv,
+                commitment: &self.permuted_input_commitment,
+                eval: self.permuted_input_inv_eval,
+            }))
+            // Open lookup product commitments at \omega^{-1} x
+            .chain(Some(VerifierQuery {
+                point: x_inv,
+                commitment: &self.product_commitment,
+                eval: self.product_inv_eval,
+            }))
+    }
+}