feat(prover): make verifier_index Arc to enable reuse of it

Author: binier

book/src/specs/kimchi.md

@@ -1729,7 +1729,7 @@ pub struct ProverIndex<G: KimchiCurve, OpeningProof: OpenProof<G>> {
 
     /// The verifier index corresponding to this prover index
     #[serde(skip)]
-    pub verifier_index: Option<VerifierIndex<G, OpeningProof>>,
+    pub verifier_index: Option<Arc<VerifierIndex<G, OpeningProof>>>,
 
     /// The verifier index digest corresponding to this prover index
     #[serde_as(as = "Option<o1_utils::serialization::SerdeAs>")]

kimchi/src/bench.rs

@@ -1,4 +1,4 @@
-use std::array;
+use std::{array, sync::Arc};
 
 use groupmap::{BWParameters, GroupMap};
 use mina_curves::pasta::{Fp, Vesta, VestaParameters};
@@ -29,7 +29,7 @@ pub struct BenchmarkCtx {
     num_gates: usize,
     group_map: BWParameters<VestaParameters>,
     index: ProverIndex<Vesta, OpeningProof<Vesta>>,
-    verifier_index: VerifierIndex<Vesta, OpeningProof<Vesta>>,
+    verifier_index: Arc<VerifierIndex<Vesta, OpeningProof<Vesta>>>,
 }
 
 impl BenchmarkCtx {

kimchi/src/prover_index.rs

@@ -47,7 +47,7 @@ pub struct ProverIndex<G: KimchiCurve, OpeningProof: OpenProof<G>> {
 
     /// The verifier index corresponding to this prover index
     #[serde(skip)]
-    pub verifier_index: Option<VerifierIndex<G, OpeningProof>>,
+    pub verifier_index: Option<Arc<VerifierIndex<G, OpeningProof>>>,
 
     /// The verifier index digest corresponding to this prover index
     #[serde_as(as = "Option<o1_utils::serialization::SerdeAs>")]

kimchi/src/verifier_index.rs

@@ -160,7 +160,7 @@ where
     /// # Panics
     ///
     /// Will panic if `srs` cannot be in `cell`.
-    pub fn verifier_index(&self) -> VerifierIndex<G, OpeningProof>
+    pub fn verifier_index(&self) -> Arc<VerifierIndex<G, OpeningProof>>
     where
         VerifierIndex<G, OpeningProof>: Clone,
     {
@@ -205,7 +205,7 @@ where
         };
 
         // TODO: Switch to commit_evaluations for all index polys
-        VerifierIndex {
+        Arc::new(VerifierIndex {
             domain,
             max_poly_size: self.max_poly_size,
             zk_rows: self.cs.zk_rows,
@@ -310,7 +310,7 @@ where
             endo: self.cs.endo,
             lookup_index,
             linearization: self.linearization.clone(),
-        }
+        })
     }
 }