1 files changed, 19 insertions, 7 deletions
diff --git a/src/store.rs b/src/store.rs
index 18a7641..98c5481 100644
--- a/src/store.rs
+++ b/src/store.rs
@@ -45,14 +45,12 @@ impl PasteStore {
 
     // ── Paste CRUD ──────────────────────────────────
 
-    /// Write a paste to disk. The key (32 bytes) is prepended
-    /// to the file so [`original_keys`] can reconstruct it.
+    /// Write a paste to disk atomically (write-to-temp + rename).
+    /// The key (32 bytes) is prepended to the file so
+    /// [`original_keys`] can reconstruct it.
     pub fn put_paste(&self, key: &[u8], value: &[u8]) -> std::io::Result<()> {
         let path = self.paste_path(key);
-        let mut f = fs::File::create(path)?;
-        f.write_all(key)?;
-        f.write_all(value)?;
-        Ok(())
+        atomic_write(&path, &[key, value])
     }
 
     /// Read a paste from disk. Returns `None` if the paste
@@ -179,6 +177,20 @@ impl PasteStore {
     }
 }
 
+/// Write data to `path` atomically: write to a temporary file in
+/// the same directory, then rename over the target. This prevents
+/// corruption if the process is killed mid-write.
+fn atomic_write(path: &Path, chunks: &[&[u8]]) -> std::io::Result<()> {
+    let parent = path.parent().unwrap_or(Path::new("."));
+    let tmp = parent.join(format!(".tmp.{}", std::process::id()));
+    let mut f = fs::File::create(&tmp)?;
+    for chunk in chunks {
+        f.write_all(chunk)?;
+    }
+    f.sync_all()?;
+    fs::rename(&tmp, path)
+}
+
 // ── tesseras-dht persistence traits ─────────────────
 
 impl tesseras_dht::persist::RoutingPersistence for PasteStore {
@@ -198,7 +210,7 @@ impl tesseras_dht::persist::RoutingPersistence for PasteStore {
             buf.extend_from_slice(id);
             buf.extend_from_slice(addr_bytes);
         }
-        fs::write(&path, &buf).map_err(tesseras_dht::Error::Io)?;
+        atomic_write(&path, &[&buf]).map_err(tesseras_dht::Error::Io)?;
         log::info!("store: persisted {} routing contacts", contacts.len());
         Ok(())
     }