pgLab/pglablib/ASyncDBConnection.h

95 lines
2.6 KiB
C++

#ifndef ASYNCDBCONNECTION_H
#define ASYNCDBCONNECTION_H
#include <QObject>
#include "Pgsql_Connection.h"
#include "Pgsql_Params.h"
#include "Pgsql_Result.h"
#include "Expected.h"
#include "ConnectionConfig.h"
#include <QElapsedTimer>
#include <mutex>
#include <memory>
class ASyncDBConnectionThread;
/** \brief Class that handles asynchronous execution of queries.
*
* Queries are passed to this class with a routine to call on completion
* when the result is on that routine is called.
*/
class ASyncDBConnection: public QObject {
Q_OBJECT
public:
enum class State {
NotConnected,
Connecting,
Connected, ///< connected and idle
QuerySend, ///< connected query send expecting result
CancelSend, ///< cancel send expecting result
Terminating ///< shutting down
};
using on_result_callback = std::function<void(Expected<std::shared_ptr<Pgsql::Result>>, qint64)>;
explicit ASyncDBConnection();
~ASyncDBConnection();
State state() const;
void setupConnection(const ConnectionConfig &config);
void closeConnection();
/** Sends command to the server.
When the result is in on_result will be called directly within the thread.
If the command gives multiple results on_result will be called for each result.
*/
bool send(const std::string &command, on_result_callback on_result);
bool send(const std::string &command, Pgsql::Params params, on_result_callback on_result);
/** This version of send uses the signal onQueryResult and onQueryError to report back
* the completion of the query.
*/
// bool send(const std::string &command, Pgsql::Params params = Pgsql::Params())
// {
// return send(command, params, [this] (Expected<std::shared_ptr<Pgsql::Result>> res, qint64) {
// if (res.valid()) {
// emit onQueryResult(res.get());
// }
// else {
// emit onQueryError();
// }
// });
// }
bool cancel();
signals:
void onStateChanged(ASyncDBConnection::State state);
void onNotice(Pgsql::ErrorDetails notice);
// void onQueryResult(std::shared_ptr<Pgsql::Result> result);
// void onQueryError();
private:
Pgsql::Connection m_connection;
std::unique_ptr<ASyncDBConnectionThread> m_threadData;
std::thread m_thread;
ConnectionConfig m_config;
State m_state = State::NotConnected;
Pgsql::Canceller m_canceller;
QElapsedTimer m_timer;
void doStateCallback(State state);
void processNotice(const PGresult *result);
friend class ASyncDBConnectionThread;
};
Q_DECLARE_METATYPE(ASyncDBConnection::State);
Q_DECLARE_METATYPE(Pgsql::ErrorDetails);
Q_DECLARE_METATYPE(std::shared_ptr<Pgsql::Result>);
#endif // ASYNCDBCONNECTION_H