diff --git a/average.hpp b/average.hpp
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+#pragma once
+
+#include "sensorset.hpp"
+
+#include <optional>
+#include <string>
+#include <vector>
+
+/** @class AverageHandling
+ *  @brief Handle avergae value when AVERAGE_* is set in env
+ */
+class Average
+{
+  public:
+    /** @brief The key type of average_set */
+    using averageKey = SensorSet::key_type;
+
+    /** @brief <average, average_interval>
+     *  average is the value of power*_average.
+     *  average_interval is the value of power*_average_interval.
+     */
+    using averageValue = std::pair<int64_t, int64_t>;
+
+    /** @brief Store sensors' <averageKey, averageValue> map */
+    using averageMap = std::map<averageKey, averageValue>;
+
+    /** @brief Get averageValue in averageMap based on averageKey.
+     *  This function will be called only when the env AVERAGE_xxx is set to
+     *  true.
+     *
+     *  @param[in] sensorKey - Sensor details
+     *
+     *  @return - Optional
+     *      return {}, if sensorKey can not be found in averageMap
+     *      return averageValue, if sensorKey can be found in averageMap
+     */
+    std::optional<averageValue>
+        getAverageValue(const averageKey& sensorKey) const;
+
+    /** @brief Set average value in averageMap based on sensor key.
+     *  This function will be called only when the env AVERAGE_xxx is set to
+     *  true.
+     *
+     *  @param[in] sensorKey - Sensor details
+     *  @param[in] sensorValue - The related average values of this sensor
+     */
+    void setAverageValue(const averageKey& sensorKey,
+                         const averageValue& sensorValue);
+
+    /** @brief Calculate the average value.
+     *
+     *  @param[in] preAverage - The previous average value from *_average file
+     *  @param[in] preInterval - The previous interval value from
+     *                           *_average_interval file
+     *  @param[in] curAverage - The current average value from *_average file
+     *  @param[in] curInterval - The current interval value from
+     *                           *_average_interval file
+     *
+     *  @return value - Optional
+     *      return {}, if curInterval-preInterval=0
+     *      return new calculated average value, if curInterval-preInterval>0
+     */
+    static std::optional<int64_t> calcAverage(int64_t preAverage,
+                                              int64_t preInterval,
+                                              int64_t curAverage,
+                                              int64_t curInterval);
+
+  private:
+    /** @brief Store the previous average sensor map */
+    averageMap _previousAverageMap;
+};
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