refs #649, refs #656, using caches in ICAO data reader

* access to info data reader (get DB metadata)
* adjusted database base class to support caches, info objects
* moved classes to subdir

src/blackcore/db/databasereader.h

@@ -0,0 +1,172 @@
+/* Copyright (C) 2015
+ * swift project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+//! \file
+
+#ifndef BLACKCORE_DB_DATABASEREADER_H
+#define BLACKCORE_DB_DATABASEREADER_H
+
+#include "blackcore/blackcoreexport.h"
+#include "blackcore/db/databasereaderconfig.h"
+#include "blackmisc/db/dbinfolist.h"
+#include "blackmisc/pq/time.h"
+#include "blackmisc/network/url.h"
+#include "blackmisc/statusmessage.h"
+#include "blackmisc/threadedreader.h"
+#include "blackmisc/sequence.h"
+#include "blackmisc/valueobject.h"
+
+#include <QDateTime>
+#include <QJsonArray>
+#include <QObject>
+#include <QReadWriteLock>
+#include <QString>
+#include <QTimer>
+#include <QtGlobal>
+
+class QNetworkReply;
+namespace BlackMisc { class CLogCategoryList; }
+
+namespace BlackCore
+{
+    namespace Db
+    {
+        //! Specialized version of threaded reader for DB data
+        class BLACKCORE_EXPORT CDatabaseReader : public BlackMisc::CThreadedReader
+        {
+            Q_OBJECT
+
+        public:
+            //!  Response from our database
+            struct JsonDatastoreResponse
+            {
+                QJsonArray m_jsonArray;              //!< JSON array data
+                QDateTime  m_updated;                //!< when was the latest updated?
+                bool       m_restricted = false;     //!< restricted reponse, only data changed
+                BlackMisc::CStatusMessage m_message; //!< last error or warning
+
+                //! Any data?
+                bool isEmpty() const { return m_jsonArray.isEmpty(); }
+
+                //! Number of elements
+                int size() const { return m_jsonArray.size(); }
+
+                //! Any timestamp?
+                bool hasTimestamp() const { return m_updated.isValid(); }
+
+                //! Is response newer?
+                bool isNewer(const QDateTime &ts) const { return m_updated.toMSecsSinceEpoch() > ts.toMSecsSinceEpoch(); }
+
+                //! Is response newer?
+                bool isNewer(qint64 mSecsSinceEpoch) const { return m_updated.toMSecsSinceEpoch() > mSecsSinceEpoch; }
+
+                //! Incremental data
+                bool isRestricted() const { return m_restricted; }
+
+                //! Error message?
+                bool hasErrorMessage() const { return m_message.getSeverity() == BlackMisc::CStatusMessage::SeverityError; }
+
+                //! Warning or error message?
+                bool hasWarningOrAboveMessage() const { return m_message.isWarningOrAbove(); }
+
+                //! Last error or warning
+                const BlackMisc::CStatusMessage &lastWarningOrAbove() const { return m_message; }
+
+                //! Set the error/warning message
+                void setMessage(const BlackMisc::CStatusMessage &lastErrorOrWarning) { m_message = lastErrorOrWarning; }
+
+                //! Get the JSON array
+                QJsonArray getJsonArray() const { return m_jsonArray; }
+
+                //! Set the JSON array
+                void setJsonArray(const QJsonArray &value) { m_jsonArray = value; }
+
+                //! Implicit conversion
+                operator QJsonArray() const { return m_jsonArray; }
+            };
+
+            //! Start reading in own thread
+            void readInBackgroundThread(BlackMisc::Network::CEntityFlags::Entity entities, const QDateTime &newerThan);
+
+            //! Can connect to DB
+            //! \threadsafe
+            bool canConnect() const;
+
+            //! Can connect to server?
+            //! \return message why connect failed
+            //! \threadsafe
+            bool canConnect(QString &message) const;
+
+            //! Obtain a working shared URL
+            BlackMisc::Network::CUrl getWorkingSharedUrl() const;
+
+            //! Status message (error message)
+            const QString &getStatusMessage() const;
+
+            //! Log categories
+            static const BlackMisc::CLogCategoryList &getLogCategories();
+
+            //! Name of latest timestamp
+            static const QString &parameterLatestTimestamp();
+
+            //! Name of parameter for latest id
+            static const QString &parameterLatestId();
+
+        protected:
+            CDatabaseReaderConfigList m_config;                 //!< DB reder configuration
+            BlackMisc::Network::CUrl  m_sharedUrl;              //!< URL for checking if alive
+            QString                   m_statusMessage;          //!< Returned status message from watchdog
+            bool                      m_canConnect = false;     //!< Successful connection?
+            mutable QReadWriteLock    m_statusLock;             //!< Lock
+
+            //! Constructor
+            CDatabaseReader(QObject *owner, const CDatabaseReaderConfigList &config, const QString &name);
+
+            //! Check if terminated or error, otherwise split into array of objects
+            CDatabaseReader::JsonDatastoreResponse setStatusAndTransformReplyIntoDatastoreResponse(QNetworkReply *nwReply);
+
+            //! Info list (latest data timestamp)
+            //! \sa BlackCore::Db::CInfoDataReader
+            BlackMisc::Db::CDbInfoList infoList() const;
+
+            //! Info objects available?
+            bool hasInfoObjects() const;
+
+            //! Obtain latest object timestamp
+            //! \sa BlackCore::Db::CInfoDataReader
+            QDateTime getLatestEntityTimestamp(BlackMisc::Network::CEntityFlags::Entity entity) const;
+
+            //! Config for given entity
+            CDatabaseReaderConfig getConfigForEntity(BlackMisc::Network::CEntityFlags::Entity entity) const;
+
+            //! Syncronize caches for given entities
+            virtual void syncronizeCaches(BlackMisc::Network::CEntityFlags::Entity entities) = 0;
+
+            //! Cache`s timestamp for given entity
+            virtual QDateTime getCacheTimestamp(BlackMisc::Network::CEntityFlags::Entity entities) = 0;
+
+            //! Invalidate the caches for given entities
+            virtual void invalidateCaches(BlackMisc::Network::CEntityFlags::Entity entities) = 0;
+
+        private:
+            //! Check if terminated or error, otherwise split into array of objects
+            JsonDatastoreResponse transformReplyIntoDatastoreResponse(QNetworkReply *nwReply) const;
+
+            //! Feedback about connection status
+            //! \threadsafe
+            void setConnectionStatus(bool ok, const QString &message = "");
+
+            //! Feedback about connection status
+            //! \threadsafe
+            void setConnectionStatus(QNetworkReply *nwReply);
+        };
+    } // ns
+} // ns
+
+#endif // guard