Cache votes list fetched for audit page (#657)

Signed-off-by: Sergio Castaño Arteaga <tegioz@icloud.com>

Author: tegioz

src/db.rs

@@ -1,13 +1,17 @@
 //! This module defines an abstraction layer over the database.
 
 use std::sync::Arc;
+#[cfg(not(test))]
+use std::time::Duration;
 
 use anyhow::Result;
 use async_trait::async_trait;
+#[cfg(not(test))]
+use cached::proc_macro::cached;
 use deadpool_postgres::{Pool, Transaction};
 #[cfg(test)]
 use mockall::automock;
-use tokio_postgres::types::Json;
+use tokio_postgres::{Client, types::Json};
 use uuid::Uuid;
 
 use crate::{
@@ -285,22 +289,36 @@ impl DB for PgDB {
 
     /// [`DB::list_votes`]
     async fn list_votes(&self, repository_full_name: &str) -> Result<Vec<Vote>> {
-        let db = self.pool.get().await?;
-        let votes = db
-            .query(
-                "
-                select *
-                from vote
-                where repository_full_name = $1::text
-                order by created_at desc
-                ",
-                &[&repository_full_name],
+        #[cfg_attr(
+            not(test),
+            cached(
+                time = 900,
+                key = "String",
+                convert = r#"{ repository_full_name.to_owned() }"#,
+                sync_writes = "by_key",
+                result = true
             )
-            .await?
-            .iter()
-            .map(Vote::from)
-            .collect();
-        Ok(votes)
+        )]
+        async fn inner(client: &Client, repository_full_name: &str) -> Result<Vec<Vote>> {
+            let votes = client
+                .query(
+                    "
+                    select *
+                    from vote
+                    where repository_full_name = $1::text
+                    order by created_at desc
+                    ",
+                    &[&repository_full_name],
+                )
+                .await?
+                .iter()
+                .map(Vote::from)
+                .collect();
+            Ok(votes)
+        }
+
+        let client = self.pool.get().await?;
+        inner(client.as_ref(), repository_full_name).await
     }
 
     /// [`DB::store_vote`]