WordClockESP/lib/framework/StatefulService.h
rjwats 0d39c5ca00
Apply updates alternative (#135)
* Rename "serialize" and "deserialize" functions to "read" and "update" to reflect API in StatefulService
* Move new definitions to StatefulService.h so it is obvious it is not general purpose
* Update README
2020-05-29 20:18:43 +01:00

149 lines
4.0 KiB
C++

#ifndef StatefulService_h
#define StatefulService_h
#include <Arduino.h>
#include <ArduinoJson.h>
#include <list>
#include <functional>
#ifdef ESP32
#include <freertos/FreeRTOS.h>
#include <freertos/semphr.h>
#endif
#ifndef DEFAULT_BUFFER_SIZE
#define DEFAULT_BUFFER_SIZE 1024
#endif
enum class StateUpdateResult {
CHANGED = 0, // The update changed the state and propagation should take place if required
UNCHANGED, // The state was unchanged, propagation should not take place
ERROR // There was a problem updating the state, propagation should not take place
};
template <class T>
using JsonStateUpdater = StateUpdateResult (*)(JsonObject& root, T& settings);
template <class T>
using JsonStateReader = void (*)(T& settings, JsonObject& root);
typedef size_t update_handler_id_t;
typedef std::function<void(const String& originId)> StateUpdateCallback;
typedef struct StateUpdateHandlerInfo {
static update_handler_id_t currentUpdatedHandlerId;
update_handler_id_t _id;
StateUpdateCallback _cb;
bool _allowRemove;
StateUpdateHandlerInfo(StateUpdateCallback cb, bool allowRemove) :
_id(++currentUpdatedHandlerId), _cb(cb), _allowRemove(allowRemove){};
} StateUpdateHandlerInfo_t;
template <class T>
class StatefulService {
public:
template <typename... Args>
#ifdef ESP32
StatefulService(Args&&... args) :
_state(std::forward<Args>(args)...), _accessMutex(xSemaphoreCreateRecursiveMutex()) {
}
#else
StatefulService(Args&&... args) : _state(std::forward<Args>(args)...) {
}
#endif
update_handler_id_t addUpdateHandler(StateUpdateCallback cb, bool allowRemove = true) {
if (!cb) {
return 0;
}
StateUpdateHandlerInfo_t updateHandler(cb, allowRemove);
_updateHandlers.push_back(updateHandler);
return updateHandler._id;
}
void removeUpdateHandler(update_handler_id_t id) {
for (auto i = _updateHandlers.begin(); i != _updateHandlers.end();) {
if ((*i)._allowRemove && (*i)._id == id) {
i = _updateHandlers.erase(i);
} else {
++i;
}
}
}
StateUpdateResult update(std::function<StateUpdateResult(T&)> stateUpdater, const String& originId) {
beginTransaction();
StateUpdateResult result = stateUpdater(_state);
endTransaction();
if (result == StateUpdateResult::CHANGED) {
callUpdateHandlers(originId);
}
return result;
}
StateUpdateResult updateWithoutPropagation(std::function<StateUpdateResult(T&)> stateUpdater) {
beginTransaction();
StateUpdateResult result = stateUpdater(_state);
endTransaction();
return result;
}
StateUpdateResult update(JsonObject& jsonObject, JsonStateUpdater<T> stateUpdater, const String& originId) {
beginTransaction();
StateUpdateResult result = stateUpdater(jsonObject, _state);
endTransaction();
if (result == StateUpdateResult::CHANGED) {
callUpdateHandlers(originId);
}
return result;
}
StateUpdateResult updateWithoutPropagation(JsonObject& jsonObject, JsonStateUpdater<T> stateUpdater) {
beginTransaction();
StateUpdateResult result = stateUpdater(jsonObject, _state);
endTransaction();
return result;
}
void read(std::function<void(T&)> stateReader) {
beginTransaction();
stateReader(_state);
endTransaction();
}
void read(JsonObject& jsonObject, JsonStateReader<T> stateReader) {
beginTransaction();
stateReader(_state, jsonObject);
endTransaction();
}
void callUpdateHandlers(const String& originId) {
for (const StateUpdateHandlerInfo_t& updateHandler : _updateHandlers) {
updateHandler._cb(originId);
}
}
protected:
T _state;
inline void beginTransaction() {
#ifdef ESP32
xSemaphoreTakeRecursive(_accessMutex, portMAX_DELAY);
#endif
}
inline void endTransaction() {
#ifdef ESP32
xSemaphoreGiveRecursive(_accessMutex);
#endif
}
private:
#ifdef ESP32
SemaphoreHandle_t _accessMutex;
#endif
std::list<StateUpdateHandlerInfo_t> _updateHandlers;
};
#endif // end StatefulService_h