feat: add timeout for set command on hashes and add function to allow retry in database (#509)

crates/router/src/utils/db_utils.rs

@@ -1,3 +1,5 @@
+use crate::{core::errors, routes::metrics};
+
 #[cfg(feature = "kv_store")]
 /// Generates hscan field pattern. Suppose the field is pa_1234_ref_1211 it will generate
 /// pa_1234_ref_*
@@ -8,3 +10,26 @@ pub fn generate_hscan_pattern_for_refund(sk: &str) -> String {
         .collect::<Vec<&str>>()
         .join("_")
 }
+
+// The first argument should be a future while the second argument should be a closure that returns a future for a database call
+pub async fn try_redis_get_else_try_database_get<F, RFut, DFut, T>(
+    redis_fut: RFut,
+    database_call_closure: F,
+) -> errors::CustomResult<T, errors::StorageError>
+where
+    F: FnOnce() -> DFut,
+    RFut: futures::Future<Output = errors::CustomResult<T, redis_interface::errors::RedisError>>,
+    DFut: futures::Future<Output = errors::CustomResult<T, errors::StorageError>>,
+{
+    let redis_output = redis_fut.await;
+    match redis_output {
+        Ok(output) => Ok(output),
+        Err(redis_error) => match redis_error.current_context() {
+            redis_interface::errors::RedisError::NotFound => {
+                metrics::KV_MISS.add(&metrics::CONTEXT, 1, &[]);
+                database_call_closure().await
+            }
+            _ => Err(redis_error.change_context(errors::StorageError::KVError)),
+        },
+    }
+}