first pass of merging in warp (doesn't build)

crates/cloud_object_persistence/src/refresh.rs

@@ -0,0 +1,34 @@
+use chrono::{DateTime, NaiveDateTime, Utc};
+use diesel::result::Error;
+use diesel::{Connection, QueryDsl, RunQueryDsl, SqliteConnection};
+use persistence::model::NewCloudObjectsRefresh;
+use persistence::schema;
+
+pub fn record_time_of_next_refresh(
+    conn: &mut SqliteConnection,
+    timestamp: DateTime<Utc>,
+) -> Result<(), Error> {
+    use schema::cloud_objects_refreshes::dsl::*;
+    let refresh = NewCloudObjectsRefresh {
+        time_of_next_refresh: timestamp.naive_utc(),
+    };
+    conn.transaction::<(), Error, _>(|conn| {
+        diesel::delete(cloud_objects_refreshes).execute(conn)?;
+        diesel::insert_into(cloud_objects_refreshes)
+            .values(refresh)
+            .execute(conn)?;
+        Ok(())
+    })
+}
+
+pub fn read_time_of_next_force_object_refresh(
+    conn: &mut SqliteConnection,
+) -> Result<Option<DateTime<Utc>>, Error> {
+    // Find the smallest refresh timestamp to pass into CloudModel.
+    Ok(cloud_objects_refreshes
+        .select(time_of_next_refresh)
+        .load::<NaiveDateTime>(conn)?
+        .into_iter()
+        .map(|refresh| refresh.and_utc())
+        .min())
+}