From f1b9b366a736b892757ba27a56cd3c4e06493636 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Grzegorz=20=C5=9Awirski?= <grzegorz@swirski.name>
Date: Thu, 27 Feb 2025 14:47:45 +0100
Subject: [PATCH] reuse Prover between requests

---
 bin/proving-service/src/api/mod.rs                |  2 +-
 crates/miden-proving-service-client/src/prover.rs |  2 +-
 crates/miden-tx/src/prover/mod.rs                 | 10 ++++++----
 crates/miden-tx/src/tests/mod.rs                  |  2 +-
 crates/miden-tx/tests/integration/main.rs         |  2 +-
 5 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/bin/proving-service/src/api/mod.rs b/bin/proving-service/src/api/mod.rs
index bc75b53d3..eb69a6fbb 100644
--- a/bin/proving-service/src/api/mod.rs
+++ b/bin/proving-service/src/api/mod.rs
@@ -47,7 +47,7 @@ impl ProverApi for ProverRpcApi {
         request: Request<ProveTransactionRequest>,
     ) -> Result<Response<ProveTransactionResponse>, tonic::Status> {
         // Try to acquire a permit without waiting
-        let prover = self
+        let mut prover = self
             .local_prover
             .try_lock()
             .map_err(|_| Status::resource_exhausted("Server is busy handling another request"))?;
diff --git a/crates/miden-proving-service-client/src/prover.rs b/crates/miden-proving-service-client/src/prover.rs
index 58385cbda..03a0bb1a5 100644
--- a/crates/miden-proving-service-client/src/prover.rs
+++ b/crates/miden-proving-service-client/src/prover.rs
@@ -69,7 +69,7 @@ impl RemoteTransactionProver {
 #[async_trait::async_trait(?Send)]
 impl TransactionProver for RemoteTransactionProver {
     async fn prove(
-        &self,
+        &mut self,
         tx_witness: TransactionWitness,
     ) -> Result<ProvenTransaction, TransactionProverError> {
         use miden_objects::utils::Serializable;
diff --git a/crates/miden-tx/src/prover/mod.rs b/crates/miden-tx/src/prover/mod.rs
index 6d127f8a5..bebdbf97e 100644
--- a/crates/miden-tx/src/prover/mod.rs
+++ b/crates/miden-tx/src/prover/mod.rs
@@ -31,7 +31,7 @@ pub trait TransactionProver {
     /// - If the transaction result is corrupt.
     #[maybe_async]
     fn prove(
-        &self,
+        &mut self,
         tx_witness: TransactionWitness,
     ) -> Result<ProvenTransaction, TransactionProverError>;
 }
@@ -43,6 +43,7 @@ pub trait TransactionProver {
 ///
 /// Local Transaction Prover implements the [TransactionProver] trait.
 pub struct LocalTransactionProver {
+    prover: Prover,
     mast_store: Arc<TransactionMastStore>,
     proof_options: ProvingOptions,
 }
@@ -51,6 +52,7 @@ impl LocalTransactionProver {
     /// Creates a new [LocalTransactionProver] instance.
     pub fn new(proof_options: ProvingOptions) -> Self {
         Self {
+            prover: Prover::new(),
             mast_store: Arc::new(TransactionMastStore::new()),
             proof_options,
         }
@@ -68,6 +70,7 @@ impl LocalTransactionProver {
 impl Default for LocalTransactionProver {
     fn default() -> Self {
         Self {
+            prover: Prover::new(),
             mast_store: Arc::new(TransactionMastStore::new()),
             proof_options: Default::default(),
         }
@@ -78,7 +81,7 @@ impl Default for LocalTransactionProver {
 impl TransactionProver for LocalTransactionProver {
     #[maybe_async]
     fn prove(
-        &self,
+        &mut self,
         tx_witness: TransactionWitness,
     ) -> Result<ProvenTransaction, TransactionProverError> {
         let TransactionWitness {
@@ -114,8 +117,7 @@ impl TransactionProver for LocalTransactionProver {
         )
         .map_err(TransactionProverError::TransactionHostCreationFailed)?;
 
-        let mut prover = Prover::new();
-        let (stack_outputs, proof) = maybe_await!(prover.prove(
+        let (stack_outputs, proof) = maybe_await!(self.prover.prove(
             &TransactionKernel::main(),
             stack_inputs,
             &mut host,
diff --git a/crates/miden-tx/src/tests/mod.rs b/crates/miden-tx/src/tests/mod.rs
index 09ba08157..f6fc900f5 100644
--- a/crates/miden-tx/src/tests/mod.rs
+++ b/crates/miden-tx/src/tests/mod.rs
@@ -821,7 +821,7 @@ fn prove_witness_and_verify() {
     let executed_transaction_id = executed_transaction.id();
 
     let proof_options = ProvingOptions::default();
-    let prover = LocalTransactionProver::new(proof_options);
+    let mut prover = LocalTransactionProver::new(proof_options);
     let proven_transaction = prover.prove(executed_transaction.into()).unwrap();
 
     assert_eq!(proven_transaction.id(), executed_transaction_id);
diff --git a/crates/miden-tx/tests/integration/main.rs b/crates/miden-tx/tests/integration/main.rs
index 9842315a6..3b649b626 100644
--- a/crates/miden-tx/tests/integration/main.rs
+++ b/crates/miden-tx/tests/integration/main.rs
@@ -49,7 +49,7 @@ pub fn prove_and_verify_transaction(
     // Prove the transaction
 
     let proof_options = ProvingOptions::default();
-    let prover = LocalTransactionProver::new(proof_options);
+    let mut prover = LocalTransactionProver::new(proof_options);
     let proven_transaction = prover.prove(executed_transaction.into()).unwrap();
 
     assert_eq!(proven_transaction.id(), executed_transaction_id);