initial public commit

tools/store/store.go

@@ -0,0 +1,84 @@
+package store
+
+import "sync"
+
+// Store defines a concurrent safe in memory key-value data store.
+type Store[T any] struct {
+	mux  sync.RWMutex
+	data map[string]T
+}
+
+// New creates a new Store[T] instance.
+func New[T any](data map[string]T) *Store[T] {
+	return &Store[T]{data: data}
+}
+
+// Remove removes a single entry from the store.
+//
+// Remove does nothing if key doesn't exist in the store.
+func (s *Store[T]) Remove(key string) {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+
+	delete(s.data, key)
+}
+
+// Has checks if element with the specified key exist or not.
+func (s *Store[T]) Has(key string) bool {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+
+	_, ok := s.data[key]
+
+	return ok
+}
+
+// Get returns a single element value from the store.
+//
+// If key is not set, the zero T value is returned.
+func (s *Store[T]) Get(key string) T {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+
+	return s.data[key]
+}
+
+// Set sets (or overwrite if already exist) a new value for key.
+func (s *Store[T]) Set(key string, value T) {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+
+	if s.data == nil {
+		s.data = make(map[string]T)
+	}
+
+	s.data[key] = value
+}
+
+// SetIfLessThanLimit sets (or overwrite if already exist) a new value for key.
+//
+// This is method is similar to Set() but **it will skip adding new elements**
+// to the store if the store length has reached the specified limit.
+// `false` is returned if maxAllowedElements limit is reached.
+func (s *Store[T]) SetIfLessThanLimit(key string, value T, maxAllowedElements int) bool {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+
+	// init map if not already
+	if s.data == nil {
+		s.data = make(map[string]T)
+	}
+
+	// check for existing item
+	_, ok := s.data[key]
+
+	if !ok && len(s.data) >= maxAllowedElements {
+		// cannot add more items
+		return false
+	}
+
+	// add/overwrite item
+	s.data[key] = value
+
+	return true
+}