QueryWorker Class Reference

The class that does all the work with the database. More...

#include <querythread.h>

Inheritance diagram for QueryWorker:

Collaboration diagram for QueryWorker:

List of all members.

Public Slots
void	slotExecute (QueryQueue *queue)
Signals
void	querying (bool)
	Emited at start and end of each query.
void	signal_result (QueryThreadCommand result)
Public Member Functions
	QueryWorker (QueryThreadConnSpecs &specs, QueryQueue *queryQueue, QObject *parent=0)
	~QueryWorker ()
QueryThreadCommand	currentCmd ()

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Detailed Description

The class that does all the work with the database.

Normally, this class is instantiated in the QueryThread's run() method.

Todo:

The QueryWorker should be aware of his initializer, and should have access to his data, so that less data has to be passed at initialization time from QueryThread to QueryWorker?

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Constructor & Destructor Documentation

QueryWorker::QueryWorker	(	QueryThreadConnSpecs &	specs,
		QueryQueue *	queryQueue,
		QObject *	parent = 0
	)

    : QObject(parent), m_requester(0)
{
    createConnection(specs, "ThreadConnection");
    Q_ASSERT(queryQueue);
    this->m_queryQueue = queryQueue;
};

QueryWorker::~QueryWorker

(

)

{};

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Member Function Documentation

QueryThreadCommand QueryWorker::currentCmd

(

)

Referenced by QueryThread::currentCmd().

{
    QMutexLocker lock(&m_currentCmdMutex);
    return m_currentCmd;
}

void QueryWorker::querying

(

bool

)

[signal]

Emited at start and end of each query.

Referenced by slotExecute().

void QueryWorker::signal_result

(

QueryThreadCommand

result

)

[signal]

Referenced by slotExecute().

void QueryWorker::slotExecute

(

QueryQueue *

queue

)

[slot]

{
    QueryThreadCommand cmd = queue->dequeue();
    if (!cmd.isValid()) return;
    setCurrentCmd(cmd);

    emit querying(true);

    //Executing and setting of result;
    QSharedPointer<QSqlQuery> result;
    QSqlDatabase db = QSqlDatabase::database("ThreadConnection", false);

    if (!db.isOpen() && !db.isOpenError())
        connectToDatabase(db);

    if (cmd.isEmpty() || db.isOpenError() || !db.isOpen()) {
        qDebug() << "Threaded connection to database not open.";
        result = QSharedPointer<QSqlQuery>(new QSqlQuery());
    }
    else {
        do {
            result = QSharedPointer<QSqlQuery>(new QSqlQuery(cmd.dequeueQuery(), db));
            if (result->lastError().isValid() && !result->lastError().text().contains("canceling statement due to user request")) {
                qWarning() << "Error from DB worker thread: " << result->lastError() << "\nAborting execution...";
                qDebug() << "Caused in query: " << result->lastQuery();
                break;
            }
        } while (!cmd.isEmpty());
    }

    releaseCurrentCmd();
    cmd.setResult(result); // it's more efficient to assign a raw pointer than to copy the shared one...

    emit signal_result(cmd);
    emit querying(false);
};

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The documentation for this class was generated from the following files:

• querythread.h
• querythread.cpp