utils: slot manager

code/framework/src/utils/slot_manager.h

@@ -0,0 +1,73 @@
+/*
+ * MafiaHub OSS license
+ * Copyright (c) 2021-2023, MafiaHub. All rights reserved.
+ *
+ * This file comes from MafiaHub, hosted at https://github.com/MafiaHub/Framework.
+ * See LICENSE file in the source repository for information regarding licensing.
+ */
+
+#pragma once
+
+#include <vector>
+
+namespace Framework::Utils {
+    template <typename T>
+    class SlotManager {
+      private:
+        std::vector<bool> _occupied;
+        std::vector<T> _slots;
+        std::vector<size_t> _freeList;
+
+      public:
+        SlotManager() {
+            _occupied.reserve(64);
+            _slots.reserve(64);
+            _freeList.reserve(64);
+        }
+
+        size_t AllocateSlot(const T &val) {
+            if (_freeList.empty()) {
+                _occupied.push_back(true);
+                _slots.push_back(val);
+                return _slots.size() - 1;
+            }
+            else {
+                size_t id = _freeList.back();
+                _freeList.pop_back();
+                _slots[id]    = val;
+                _occupied[id] = true;
+                return id;
+            }
+        }
+
+        void DeallocateSlot(size_t id) {
+            if (id < _occupied.size()) {
+                _occupied[id] = false;
+                _freeList.push_back(id);
+            }
+        }
+
+        void DeallocateSlot(const T &val) {
+            for (size_t i = 0; i < _slots.size(); i++) {
+                if (_slots[i] == val) {
+                    DeallocateSlot(i);
+                    return;
+                }
+            }
+        }
+
+        T *GetSlot(size_t id) {
+            if (id < _slots.size() && _occupied[id]) {
+                return &_slots[id];
+            }
+            return nullptr;
+        }
+
+        const T *GetSlot(size_t id) const {
+            if (id < _slots.size() && _occupied[id]) {
+                return &_slots[id];
+            }
+            return nullptr;
+        }
+    };
+} // namespace Framework::Utils