fieldHandler

Author: Pavel Siska

new-process-api/fieldHandler.hpp

@@ -0,0 +1,75 @@
+/**
+ * @file
+ * @author Pavel Siska <[email protected]>
+ * @brief Handle representing a single field within a FlowRecord.
+ *
+ * This file defines the FieldHandler class which provides an interface
+ * for marking a field as available or unavailable in a FlowRecord and
+ * querying its presence status.
+ *
+ * @copyright Copyright (c) 2025 CESNET, z.s.p.o.
+ */
+
+#pragma once
+
+#include "flowRecord.hpp"
+
+#include <cstdint>
+
+namespace ipxp {
+
+/**
+ * @brief Represents a handle to a single field within a FlowRecord.
+ *
+ * FieldHandler allows checking whether a field is present in a record
+ * and provides methods to set or clear its presence flag in `FlowRecord::fieldsAvailable`.
+ */
+class FieldHandler {
+public:
+	/**
+	 * @brief Sets the associated bit in the FlowRecord to indicate field availability.
+	 *
+	 * This method modifies the mutable member `fieldsAvailable` of FlowRecord even if
+	 * the FlowRecord instance is const. This is safe and intentional, as the presence
+	 * information is considered logically mutable.
+	 *
+	 * @param record Reference to FlowRecord (can be const, modifies only mutable member).
+	 */
+	void setAsAvailable(const FlowRecord& record) const { record.fieldsAvailable.set(m_bitIndex); }
+
+	/**
+	 * @brief Clears the associated bit in the FlowRecord to indicate field unavailability.
+	 *
+	 * This method modifies the mutable member `fieldsAvailable` of FlowRecord even if
+	 * the FlowRecord instance is const. This is safe and intentional, as the presence
+	 * information is considered logically mutable.
+	 *
+	 * @param record Reference to FlowRecord (can be const, modifies only mutable member).
+	 */
+	void setAsUnavailable(const FlowRecord& record) const
+	{
+		record.fieldsAvailable.reset(m_bitIndex);
+	}
+
+	/**
+	 * @brief Returns the availability status of the field in the given FlowRecord.
+	 */
+	[[nodiscard]]
+	bool getStatus(const FlowRecord& record) const
+	{
+		return record.fieldsAvailable.test(m_bitIndex);
+	}
+
+private:
+	friend class FieldManager;
+
+	/// Constructor used only by FieldManager to create a valid handler.
+	explicit constexpr FieldHandler(std::size_t bitIndex) noexcept
+		: m_bitIndex(bitIndex)
+	{
+	}
+
+	const std::size_t m_bitIndex;
+};
+
+} // namespace ipxp