Utils: Add Cache` - ft. notify_change_callback

Add DigitalIn

src/utils.hh

@@ -174,4 +174,110 @@ namespace Heck {
         DeliverCallback deliver_cb_{};
     };
 } // namespace Heck
+
+namespace Heck {
+    template<typename T> class Cache {
+
+    public:
+        using UpdateCallback = std::function<T(void)>;
+        using NotifyChangeCallback = std::function<void(Cache<T>&)>;
+
+        Cache() = delete;
+        ~Cache() = default;
+
+        explicit Cache(UpdateCallback update_cb, NotifyChangeCallback notify_change_cb)
+        {
+            init(update_cb, notify_change_cb);
+        }
+
+        Cache(Cache&) = delete;
+        Cache& operator=(Cache) = delete;
+
+        Cache(Cache&&) = delete;
+        Cache& operator=(Cache&&) = delete;
+
+        T read()
+        {
+            return val_current_;
+        }
+
+        void set_update_callback(UpdateCallback cb)
+        {
+            update_cb_ = cb;
+        }
+
+        void set_notify_change_callback(NotifyChangeCallback cb)
+        {
+            notify_change_cb_ = cb;
+        }
+
+        bool update_and_notify_change()
+        {
+            T val_fetched{ update_cb_() };
+            if (val_fetched != val_current_) {
+                val_current_ = val_fetched;
+                notify_change_cb_(*this);
+                return true;
+            }
+            return false;
+        }
+
+        bool update_and_notify_change_fuzzy(T min_deviation)
+        {
+            T val_fetched{ update_cb_() };
+            if (std::abs(val_fetched - val_current_) >= min_deviation) {
+                val_current_ = val_fetched;
+                notify_change_cb_(*this);
+                return true;
+            }
+            return false;
+        }
+
+    private:
+        void init(UpdateCallback fetch_cb, NotifyChangeCallback deliver_cb)
+        {
+            set_update_callback(fetch_cb);
+            set_notify_change_callback(deliver_cb);
+        }
+
+        T val_current_{};
+        UpdateCallback update_cb_{};
+        NotifyChangeCallback notify_change_cb_{};
+    };
+
+    struct DigitalIn {
+    public:
+        DigitalIn() = default;
+        ~DigitalIn() = default;
+
+        DigitalIn(u8 daisy_pin)
+        {
+            init(daisy_pin);
+        }
+
+        DigitalIn(DigitalIn&) = delete;
+        DigitalIn& operator=(DigitalIn&) = delete;
+
+        DigitalIn(DigitalIn&&) = delete;
+        DigitalIn& operator=(DigitalIn&&) = delete;
+
+        void init(u8 daisy_pin)
+        {
+            gpio_.Init(ld::DaisySeed::GetPin(daisy_pin), ld::GPIO::Mode::INPUT, ld::GPIO::Pull::PULLUP);
+        }
+
+        bool read()
+        {
+            return !gpio_.Read();
+        }
+
+        Cache<bool> cache{ [&]() -> bool { return read(); }, [](Cache<bool>&) {} };
+
+    private:
+
+        ld::GPIO gpio_{};
+    };
+
+
+} // namespace Heck
 #endif // HECK_DAISY_UTILS_HH`