diff --git a/backend/src/data.rs b/backend/src/data.rs
index d68166e..5439e68 100644
--- a/backend/src/data.rs
+++ b/backend/src/data.rs
@@ -1,3 +1,11 @@
+use crate::{
+    cache::{Cache, Key},
+    service::Service,
+};
+use std::sync::{Arc, RwLock};
+
+pub(crate) type State = Arc<RwLock<Cache<Key, String>>>;
+
 #[derive(Deserialize, Debug)]
 pub(crate) struct FilePath {
     pub(crate) user: String,
@@ -6,3 +14,17 @@ pub(crate) struct FilePath {
     pub(crate) file: String,
 }
 
+impl FilePath {
+    pub(crate) fn path(&self) -> String {
+        format!("{}/{}/{}/{}", self.user, self.repo, self.commit, self.file)
+    }
+
+    pub(crate) fn to_key<T: Service>(&self) -> Key {
+        Key::new(
+            T::cache_service(),
+            self.user.clone(),
+            self.repo.clone(),
+            self.commit.clone(),
+        )
+    }
+}