feat: add KV Storage

src/kv/mem.rs

@@ -0,0 +1,84 @@
+use std::collections::HashMap;
+
+/// In-memory key-value store.
+#[derive(Debug, Clone)]
+pub struct MemKVStore<K, V> {
+    store: HashMap<K, V>,
+}
+
+impl<K, V> MemKVStore<K, V>
+where
+    K: Eq + std::hash::Hash,
+{
+    /// Create a new `MemKVStore`.
+    pub fn new() -> Self {
+        MemKVStore {
+            store: HashMap::new(),
+        }
+    }
+
+    /// Insert a key-value pair into the store.
+    pub fn insert(&mut self, key: K, value: V) {
+        self.store.insert(key, value);
+    }
+
+    /// Get the value associated with a key.
+    pub fn get(&self, key: &K) -> Option<&V> {
+        self.store.get(key)
+    }
+
+    /// Remove a key-value pair from the store.
+    pub fn remove(&mut self, key: &K) -> Option<V> {
+        self.store.remove(key)
+    }
+
+    /// Check if the store contains a key.
+    pub fn contains_key(&self, key: &K) -> bool {
+        self.store.contains_key(key)
+    }
+
+    /// Get the number of key-value pairs in the store.
+    pub fn len(&self) -> usize {
+        self.store.len()
+    }
+
+    /// Check if the store is empty.
+    pub fn is_empty(&self) -> bool {
+        self.store.is_empty()
+    }
+}
+
+impl<K, V> Default for MemKVStore<K, V>
+where
+    K: Eq + std::hash::Hash,
+{
+    fn default() -> Self {
+        MemKVStore::new()
+    }
+}
+
+impl<K, V> super::KVStore for MemKVStore<K, V>
+where
+    K: Eq + std::hash::Hash + Clone + AsRef<[u8]>,
+    V: Clone + AsRef<[u8]>,
+{
+    type Key = K;
+
+    type Value = V;
+
+    fn get(&self, key: &Self::Key) -> Option<&Self::Value> {
+        MemKVStore::get(self, key)
+    }
+
+    fn set(&mut self, key: Self::Key, value: Self::Value) {
+        self.insert(key, value);
+    }
+
+    fn del(&mut self, key: &Self::Key) {
+        self.remove(key);
+    }
+
+    fn ex(&self, key: &Self::Key) -> bool {
+        self.contains_key(key)
+    }
+}

src/kv/mod.rs

@@ -0,0 +1,16 @@
+/// In-memory storage for the key-value store.
+mod mem;
+
+pub trait KVStore {
+    type Key: AsRef<[u8]>;
+    type Value: AsRef<[u8]>;
+
+    /// Get the value of a key.
+    fn get(&self, key: &Self::Key) -> Option<&Self::Value>;
+    /// Set the value of a key.
+    fn set(&mut self, key: Self::Key, value: Self::Value);
+    /// Remove a key, if it exists.
+    fn del(&mut self, key: &Self::Key);
+    /// Check if the key exists in the store.
+    fn ex(&self, key: &Self::Key) -> bool;
+}

src/lib.rs

@@ -6,6 +6,8 @@ use sdk::ctx::{KeystoreContext, ServicesContext, TangleClientContext};
 
 /// FROST Keygen module
 pub mod keygen;
+/// Key-Value Storage module
+mod kv;
 /// FROST Signing module
 pub mod sign;