[feat] kv_typed: add method contains_key

rust-libs/tools/kv_typed/src/backend.rs

@@ -55,6 +55,7 @@ pub trait BackendCol: 'static + Clone + Debug + Send + Sync {
         f: F,
     ) -> KvResult<Option<D>>;
     fn clear(&mut self) -> KvResult<()>;
+    fn contains_key<K: Key>(&self, k: &K) -> KvResult<bool>;
     fn count(&self) -> KvResult<usize>;
     fn iter<K: Key, V: Value>(&self, range: RangeBytes) -> Self::Iter;
     fn put<K: Key, V: Value>(&mut self, k: &K, value: &V) -> KvResult<()>;

rust-libs/tools/kv_typed/src/backend/leveldb.rs

@@ -126,6 +126,10 @@ impl BackendCol for LevelDbCol {
             .count())
     }
     #[inline(always)]
+    fn contains_key<K: Key>(&self, k: &K) -> KvResult<bool> {
+        k.as_bytes(|k_bytes| Ok(self.0.get(ReadOptions::new(), k_bytes)?.is_some()))
+    }
+    #[inline(always)]
     fn get<K: Key, V: Value>(&self, k: &K) -> KvResult<Option<V>> {
         k.as_bytes(|k_bytes| {
             self.0

rust-libs/tools/kv_typed/src/backend/memory.rs

@@ -241,6 +241,10 @@ impl BackendCol for MemCol {
         Ok(self.tree.len())
     }
     #[inline(always)]
+    fn contains_key<K: Key>(&self, k: &K) -> KvResult<bool> {
+        k.as_bytes(|k_bytes| Ok(self.tree.contains_key(k_bytes)))
+    }
+    #[inline(always)]
     fn get<K: Key, V: Value>(&self, k: &K) -> KvResult<Option<V>> {
         k.as_bytes(|k_bytes| {
             self.tree

rust-libs/tools/kv_typed/src/backend/memory_singleton.rs

@@ -81,6 +81,10 @@ impl BackendCol for MemCol {
         }
     }
     #[inline(always)]
+    fn contains_key<K: Key>(&self, _k: &K) -> KvResult<bool> {
+        Ok(self.0.is_some())
+    }
+    #[inline(always)]
     fn get<K: Key, V: Value>(&self, _k: &K) -> KvResult<Option<V>> {
         self.0
             .as_ref()

rust-libs/tools/kv_typed/src/backend/sled.rs

@@ -76,6 +76,10 @@ impl BackendCol for SledCol {
         Ok(self.0.len())
     }
     #[inline(always)]
+    fn contains_key<K: Key>(&self, k: &K) -> KvResult<bool> {
+        k.as_bytes(|k_bytes| Ok(self.0.contains_key(k_bytes)?))
+    }
+    #[inline(always)]
     fn get<K: Key, V: Value>(&self, k: &K) -> KvResult<Option<V>> {
         k.as_bytes(|k_bytes| {
             self.0

rust-libs/tools/kv_typed/src/collection_ro.rs

@@ -6,6 +6,7 @@ pub trait DbCollectionRo: Sized {
     type V: Value;
     type Event: EventTrait<K = Self::K, V = Self::V>;
 
+    fn contains_key(&self, k: &Self::K) -> KvResult<bool>;
     fn count(&self) -> KvResult<usize>;
     fn get(&self, k: &Self::K) -> KvResult<Option<Self::V>>;
     /// Don't worry about complex iter type. Use it like an `impl Iterator<Item=KvResult<(K, V)>>`.
@@ -67,6 +68,11 @@ impl<BC: BackendCol, E: EventTrait> DbCollectionRo for ColRo<BC, E> {
     type V = E::V;
     type Event = E;
 
+    #[inline(always)]
+    fn contains_key(&self, k: &Self::K) -> KvResult<bool> {
+        let r = self.inner.read();
+        r.backend_col.contains_key(k)
+    }
     #[inline(always)]
     fn count(&self) -> KvResult<usize> {
         let r = self.inner.read();