fix: Change no pending batches 404 error into a success response

core/lib/types/src/prover_server_api/mod.rs

@@ -19,7 +19,7 @@ pub struct ProofGenerationDataRequest {}
 
 #[derive(Debug, Serialize, Deserialize)]
 pub enum ProofGenerationDataResponse {
-    Success(ProofGenerationData),
+    Success(Option<ProofGenerationData>),
     Error(String),
 }
 

core/lib/zksync_core/src/proof_data_handler/request_processor.rs

@@ -31,18 +31,13 @@ pub(crate) struct RequestProcessor {
 }
 
 pub(crate) enum RequestProcessorError {
-    NoPendingBatches,
     ObjectStore(ObjectStoreError),
     Sqlx(SqlxError),
 }
 
 impl IntoResponse for RequestProcessorError {
     fn into_response(self) -> Response {
         let (status_code, message) = match self {
-            Self::NoPendingBatches => (
-                StatusCode::NOT_FOUND,
-                "No pending batches to process".to_owned(),
-            ),
             RequestProcessorError::ObjectStore(err) => {
                 tracing::error!("GCS error: {:?}", err);
                 (
@@ -88,15 +83,19 @@ impl RequestProcessor {
     ) -> Result<Json<ProofGenerationDataResponse>, RequestProcessorError> {
         tracing::info!("Received request for proof generation data: {:?}", request);
 
-        let l1_batch_number = self
+        let l1_batch_number_result = self
             .pool
             .access_storage()
             .await
             .unwrap()
             .proof_generation_dal()
             .get_next_block_to_be_proven(self.config.proof_generation_timeout())
-            .await
-            .ok_or(RequestProcessorError::NoPendingBatches)?;
+            .await;
+
+        let l1_batch_number = match l1_batch_number_result {
+            Some(number) => number,
+            None => return Ok(Json(ProofGenerationDataResponse::Success(None))), // no batches pending to be proven
+        };
 
         let blob = self
             .blob_store
@@ -125,7 +124,9 @@ impl RequestProcessor {
             l1_verifier_config,
         };
 
-        Ok(Json(ProofGenerationDataResponse::Success(proof_gen_data)))
+        Ok(Json(ProofGenerationDataResponse::Success(Some(
+            proof_gen_data,
+        ))))
     }
 
     pub(crate) async fn submit_proof(

prover/prover_fri_gateway/src/api_data_fetcher.rs

@@ -33,6 +33,7 @@ impl PeriodicApiStruct {
         Resp: DeserializeOwned,
     {
         tracing::info!("Sending request to {}", endpoint);
+
         self.client
             .post(endpoint)
             .json(&request)

prover/prover_fri_gateway/src/proof_gen_data_fetcher.rs

@@ -33,6 +33,7 @@ impl PeriodicApiStruct {
 impl PeriodicApi<ProofGenerationDataRequest> for PeriodicApiStruct {
     type JobId = ();
     type Response = ProofGenerationDataResponse;
+
     const SERVICE_NAME: &'static str = "ProofGenDataFetcher";
 
     async fn get_next_request(&self) -> Option<(Self::JobId, ProofGenerationDataRequest)> {
@@ -49,7 +50,10 @@ impl PeriodicApi<ProofGenerationDataRequest> for PeriodicApiStruct {
 
     async fn handle_response(&self, _: (), response: Self::Response) {
         match response {
-            ProofGenerationDataResponse::Success(data) => {
+            ProofGenerationDataResponse::Success(None) => {
+                tracing::info!("There are currently no pending batches to be proven");
+            }
+            ProofGenerationDataResponse::Success(Some(data)) => {
                 tracing::info!("Received proof gen data for: {:?}", data.l1_batch_number);
                 self.save_proof_gen_data(data).await;
             }