[feat] Adding Storage add_counter method

* Only used in InMemory storage for normalizing counters
* Other storage implementations return `Ok(())`
* Included in `storage.add_limit`, unwrapping for now since it can't
  fail

limitador/src/storage/disk/rocksdb_storage.rs

@@ -24,6 +24,10 @@ impl CounterStorage for RocksDbStorage {
         Ok(counter.max_value() >= value.value() + delta)
     }
 
+    fn add_counter(&self, _limit: &Limit) -> Result<(), StorageErr> {
+        Ok(())
+    }
+
     fn update_counter(&self, counter: &Counter, delta: i64) -> Result<(), StorageErr> {
         let key = key_for_counter(counter);
         self.insert_or_update(&key, counter, delta)?;

limitador/src/storage/in_memory.rs

@@ -35,6 +35,18 @@ impl CounterStorage for InMemoryStorage {
         Ok(counter.max_value() >= value + delta)
     }
 
+    fn add_counter(&self, limit: &Limit) -> Result<(), StorageErr> {
+        if limit.variables().is_empty() {
+            let mut limits_by_namespace = self.limits_for_namespace.write().unwrap();
+            limits_by_namespace
+                .entry(limit.namespace().clone())
+                .or_insert_with(HashMap::new)
+                .entry(limit.clone())
+                .or_insert_with(AtomicExpiringValue::default);
+        }
+        Ok(())
+    }
+
     fn update_counter(&self, counter: &Counter, delta: i64) -> Result<(), StorageErr> {
         let mut limits_by_namespace = self.limits_for_namespace.write().unwrap();
         let now = SystemTime::now();

limitador/src/storage/mod.rs

@@ -57,12 +57,9 @@ impl Storage {
 
     pub fn add_limit(&self, limit: Limit) -> bool {
         let namespace = limit.namespace().clone();
-        self.limits
-            .write()
-            .unwrap()
-            .entry(namespace)
-            .or_default()
-            .insert(limit)
+        let mut limits = self.limits.write().unwrap();
+        self.counters.add_counter(&limit).unwrap();
+        limits.entry(namespace).or_default().insert(limit)
     }
 
     pub fn update_limit(&self, update: &Limit) -> bool {
@@ -263,6 +260,7 @@ impl AsyncStorage {
 
 pub trait CounterStorage: Sync + Send {
     fn is_within_limits(&self, counter: &Counter, delta: i64) -> Result<bool, StorageErr>;
+    fn add_counter(&self, limit: &Limit) -> Result<(), StorageErr>;
     fn update_counter(&self, counter: &Counter, delta: i64) -> Result<(), StorageErr>;
     fn check_and_update(
         &self,

limitador/src/storage/redis/redis_sync.rs

@@ -32,6 +32,10 @@ impl CounterStorage for RedisStorage {
         }
     }
 
+    fn add_counter(&self, _limit: &Limit) -> Result<(), StorageErr> {
+        Ok(())
+    }
+
     fn update_counter(&self, counter: &Counter, delta: i64) -> Result<(), StorageErr> {
         let mut con = self.conn_pool.get()?;
 

limitador/src/storage/wasm.rs

@@ -85,6 +85,10 @@ impl CounterStorage for WasmStorage {
         Ok(self.counter_is_within_limits(counter, stored_counters.get(counter), delta))
     }
 
+    fn add_counter(&self, _limit: &Limit) -> Result<(), StorageErr> {
+        Ok(())
+    }
+
     fn update_counter(&self, counter: &Counter, delta: i64) -> Result<(), StorageErr> {
         let mut counters = self.counters.write().unwrap();
         self.insert_or_update_counter(&mut counters, counter, delta);