clean up

fix/src/fetcher/cache.rs

@@ -0,0 +1,29 @@
+use std::fs;
+use std::path::PathBuf;
+
+#[derive(Debug)]
+pub struct FetcherCache {
+    base_dir: PathBuf,
+}
+
+impl FetcherCache {
+    pub fn new() -> Result<Self, std::io::Error> {
+        let base_dir = dirs::cache_dir()
+            .unwrap_or_else(|| PathBuf::from("/tmp"))
+            .join("fix")
+            .join("fetchers");
+
+        fs::create_dir_all(&base_dir)?;
+
+        Ok(Self { base_dir })
+    }
+
+    fn git_cache_dir(&self) -> PathBuf {
+        self.base_dir.join("git")
+    }
+
+    pub fn get_git_bare(&self, url: &str) -> PathBuf {
+        let key = crate::nix_utils::sha256_hex(url.as_bytes());
+        self.git_cache_dir().join(key)
+    }
+}