minor fix in the integration with persy

src/database/abstraction.rs

@@ -80,7 +80,7 @@ impl DatabaseEngine for PersyEngine {
         let persy = persy::OpenOptions::new()
             .create(true)
             .config(cfg)
-            .open(&config.database_path)?;
+            .open(&format!("{}/db.persy", config.database_path))?;
         Ok(Arc::new(PersyEngine(persy)))
     }
 
@@ -179,19 +179,31 @@ impl Tree for PersyTree {
         from: &[u8],
         backwards: bool,
     ) -> Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a> {
-        Box::new(
+        let iter = if backwards {
+            self.db
+                .range::<persy::ByteVec, persy::ByteVec, _>(
+                    &self.name,
+                    ..persy::ByteVec(from.to_owned()),
+                )
+                .unwrap()
+        } else {
             self.db
                 .range::<persy::ByteVec, persy::ByteVec, _>(
                     &self.name,
                     persy::ByteVec(from.to_owned())..,
                 )
                 .unwrap()
-                .filter_map(|(k, v)| {
-                    v.into_iter()
-                        .map(|val| (k.0.to_owned().into(), val.0.to_owned().into()))
-                        .next()
-                }),
-        )
+        };
+        let map = iter.filter_map(|(k, v)| {
+            v.into_iter()
+                .map(|val| (k.0.to_owned().into(), val.0.to_owned().into()))
+                .next()
+        });
+        if backwards {
+            Box::new(map.rev())
+        } else {
+            Box::new(map)
+        }
     }
 
     fn increment(&self, key: &[u8]) -> Result<Vec<u8>> {
@@ -210,9 +222,10 @@ impl Tree for PersyTree {
             self.db
                 .range::<persy::ByteVec, persy::ByteVec, _>(
                     &self.name,
-                    range_prefix.clone()..=range_prefix,
+                    range_prefix..,
                 )
                 .unwrap()
+                .take_while(move |(k, _)| k.0.starts_with(&prefix))
                 .filter_map(|(k, v)| {
                     v.into_iter()
                         .map(|val| (k.0.to_owned().into(), val.0.to_owned().into()))