init

lib/data/rfid.hpp

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <Arduino.h>
+#include <LittleFS.h>
+#include <functional> // For std::function
+
+class RfidDB {
+public:
+    // The default constructor uses "/rfid.db"
+    RfidDB(const String& filename = "/rfid.db");
+    ~RfidDB();
+
+    /**
+     * @brief Initializes the filesystem and the database file.
+     * Must be called once in setup().
+     * @return true on success, otherwise false.
+     */
+    bool begin();
+
+    /**
+     * @brief Returns the number of stored IDs.
+     */
+    uint32_t count();
+
+    /**
+     * @brief Checks if an ID exists in the database.
+     * @param id The ID to check.
+     * @return true if the ID exists, otherwise false.
+     */
+    bool contains(uint32_t id);
+
+    /**
+     * @brief Adds a new ID. The ID is only added if it does not already exist.
+     * @param id The ID to add.
+     * @return true if the ID was successfully added, otherwise false.
+     */
+    bool add(uint32_t id);
+
+    /**
+     * @brief Removes an ID from the database.
+     * @param id The ID to remove.
+     * @return true if the ID was found and removed, otherwise false.
+     */
+    bool remove(uint32_t id);
+
+    /**
+     * @brief Iterates over all stored IDs and calls a callback function for each.
+     * @param callback The function to be called for each ID (e.g., a lambda: `[](uint32_t id){ Serial.println(id); }`).
+     */
+    void iterate(std::function<void(uint32_t)> callback);
+
+private:
+    String filename_;
+    String tmpFilename_;
+    bool initialized_ = false;
+
+    static constexpr size_t ENTRY_SIZE = sizeof(uint32_t);
+
+    // Helper methods
+    bool readEntryAt(File &f, uint32_t index, uint32_t &out);
+    bool writeEntryAt(File &f, uint32_t index, uint32_t value);
+    bool binarySearch(File &f, uint32_t &outIndex, uint32_t key, bool &found);
+    uint32_t byteSwap(uint32_t x) const;
+    uint32_t fileEntryCount(File &f);
+};
+
+// Global instance, kept as requested
+extern RfidDB rfidDB;