db abstraction looks good

1 files changed, 20 insertions, 22 deletions

diff --git a/database/src/backends/memory.rs b/database/src/backends/memory.rs
index 3c2fdea..302b232 100644
--- a/database/src/backends/memory.rs
+++ b/database/src/backends/memory.rs
@@ -41,33 +41,31 @@ impl ReadTransaction for RwLockWriteGuard<'_, Inner> {
     fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
         Ok((**self).get(key).cloned())
     }
-    fn next(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
-        Ok((**self)
-            .range(key.to_vec()..)
-            .next()
-            .map(|(k, _)| k.to_owned()))
-    }
-    fn prev(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
-        Ok((**self)
-            .range(..key.to_vec())
-            .next_back()
-            .map(|(k, _)| k.to_owned()))
+    fn iter<'a>(
+        &'a self,
+        key: &[u8],
+        reverse: bool,
+    ) -> Result<Box<dyn Iterator<Item = Result<Vec<u8>>> + 'a>> {
+        Ok(if reverse {
+            Box::new(self.range(key.to_vec()..).map(|e| Ok(e.0.to_vec())))
+        } else {
+            Box::new(self.range(..=key.to_vec()).rev().map(|e| Ok(e.0.to_vec())))
+        })
     }
 }
 impl ReadTransaction for RwLockReadGuard<'_, Inner> {
     fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
         Ok((**self).get(key).cloned())
     }
-    fn next(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
-        Ok((**self)
-            .range(key.to_vec()..)
-            .next()
-            .map(|(k, _)| k.to_owned()))
-    }
-    fn prev(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
-        Ok((**self)
-            .range(..key.to_vec())
-            .next_back()
-            .map(|(k, _)| k.to_owned()))
+    fn iter<'a>(
+        &'a self,
+        key: &[u8],
+        reverse: bool,
+    ) -> Result<Box<dyn Iterator<Item = Result<Vec<u8>>> + 'a>> {
+        Ok(if reverse {
+            Box::new(self.range(key.to_vec()..).map(|e| Ok(e.0.to_vec())))
+        } else {
+            Box::new(self.range(..=key.to_vec()).rev().map(|e| Ok(e.0.to_vec())))
+        })
     }
 }