Subversion Repositories public iLand

/********************************************************************************************

**    iLand - an individual based forest landscape and disturbance model

**    http://iland.boku.ac.at

**    Copyright (C) 2009-  Werner Rammer, Rupert Seidl

**

**    This program is free software: you can redistribute it and/or modify

**    it under the terms of the GNU General Public License as published by

**    the Free Software Foundation, either version 3 of the License, or

**    (at your option) any later version.

**

**    This program is distributed in the hope that it will be useful,

**    but WITHOUT ANY WARRANTY; without even the implied warranty of

**    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

**    GNU General Public License for more details.

**

**    You should have received a copy of the GNU General Public License

**    along with this program.  If not, see <http://www.gnu.org/licenses/>.

********************************************************************************************/

#include "global.h"

#include "output.h"

#include <QtCore>

#include <QtSql>

/** @class Output

   The Output class abstracts output data (database, textbased, ...).

   To create a new output, create a class derived from Output and perform the following steps:

   - Overwrite constructor:

     Create columns and set fixed properties (e.g. table name)

   - overwrite setup()

     this function is called after the project file is read. You can access a XmlHelper calling settings()

     which is set to the top-node of the output (defined by tableName() which is set in the constructor). Access settings

     using relative xml-pathes (see example).

   - overwrite exec()

     add data using the stream operators or add() function of Output. Call writeRow() after each row. Each invokation

     of exec() is a database transaction.

   - Add the output to the constructor of @c OutputManager

   @par Example

   @code

   // (1) Overwrite constructor and set name, description and columns

   TreeOut::TreeOut()

    {

        setName("Tree Output", "tree");

        setDescription("Output of indivdual trees.");

        columns() << OutputColumn("id", "id of the tree", OutInteger)

                 << OutputColumn("name", "tree species name", OutString)

                 << OutputColumn("v1", "a double value", OutDouble);

     }

    // (2) optionally: some special settings (here: filter)

    void TreeOut::setup()

    {

        QString filter = settings().value(".filter","");

        if (filter!="")

            mFilter = QSharedPointer<Expression>(new Expression(filter));

    }

    // (3) the execution

    void TreeOut::exec()

    {

        AllTreeIterator at(GlobalSettings::instance()->model());

        while (Tree *t=at.next()) {

            if (mFilter && !mFilter->execute()) // skip if filter present

                continue;

            *this << t->id() << t->species()->id() << t->dbh(); // stream operators

            writeRow(); // executes DB insert

        }

    }

    // in outputmanager.cpp:

    OutputManager::OutputManager()

    {

        ...

        mOutputs.append(new TreeOut); // add the output

        ...

    }

    @endcode

*/

const GlobalSettings *Output::gl = GlobalSettings::instance();

void Output::exec()

{

    qDebug() << "Output::exec() called! (should be overrided!)";

}

void Output::setup()

{

}

Output::~Output()

{

    mInserter.clear();

}

Output::Output()

{

    mCount=0;

    mMode = OutDatabase;

    mOpen = false;

    mEnabled = false;

    newRow();

}

/** create the database table and opens up the output.

  */

void Output::openDatabase()

{

    QSqlDatabase db = GlobalSettings::instance()->dbout();

    // create the "create table" statement

    QString sql = "create table " +mTableName + "(";

    QString insert="insert into " + mTableName + " (";

    QString values;

    foreach(const OutputColumn &col, columns()) {

        switch(col.mDatatype) {

            case OutInteger: sql+=col.mName + " integer"; break;

            case OutDouble: sql+=col.mName + " real"; break;

            case OutString: sql+=col.mName + " text"; break;

        }

        insert+=col.mName+",";

        values+=QString(":")+col.mName+",";

        sql+=",";

    }

    sql[sql.length()-1]=')'; // replace last "," with )

    //qDebug()<< sql;

    if (mInserter.isValid())

        mInserter.clear();

    QSqlQuery creator(db);

    QString drop=QString("drop table if exists %1").arg(tableName());

    creator.exec(drop); // drop table (if exists)

    creator.exec(sql); // (re-)create table

    //creator.exec("delete from " + tableName()); // clear table??? necessary?

    if (creator.lastError().isValid()){

        throw IException(QString("Error creating output: %1").arg( creator.lastError().text()) );

    }

    insert[insert.length()-1]=')';

    values[values.length()-1]=')';

    insert += QString(" values (") + values;

    //qDebug() << insert;

    mInserter = QSqlQuery(db);

    mInserter.prepare(insert);

    if (mInserter.lastError().isValid()){

        throw IException(QString("Error creating output: %1").arg( mInserter.lastError().text()) );

    }

    for (int i=0;i<columns().count();i++)

        mInserter.bindValue(i,mRow[i]);

    mOpen = true;

}

void Output::newRow()

{

    mIndex = 0;

}

void Output::writeRow()

{

    DBG_IF(mIndex!=mCount, "Output::save()", "received invalid number of values!");

    if (!isOpen())

        open();

    switch(mMode) {

        case OutDatabase:

            saveDatabase(); break;

        default: throw IException("Invalid output mode");

    }

}

void Output::open()

{

    if (isOpen())

        return;

    // setup columns

    mCount = columns().count();

    mRow.resize(mCount);

    mOpen = true;

    newRow();

    // setup output

    switch(mMode) {

        case OutDatabase:

            openDatabase(); break;

        default: throw IException("Invalid output mode");

    }

}

void Output::close()

{

    if (!isOpen())

        return;

    mOpen = false;

    switch (mMode) {

        case OutDatabase:

            // calling finish() ensures, that the query and all locks are freed.

            // having (old) locks on database connections, degrades insert performance.

            if (mInserter.isValid())

                mInserter.finish();

            mInserter = QSqlQuery(); // clear inserter

         break;

        default:

         qWarning() << "Output::close with invalid mode";

    }

}

void Output::saveDatabase()

{

   for (int i=0;i<mCount;i++)

        mInserter.bindValue(i,mRow[i]);

    mInserter.exec();

    if (mInserter.lastError().isValid()){

        throw IException(QString("Error during saving of output tables: '%1'' (native code: '%2', driver: '%3')")

                         .arg( mInserter.lastError().text())

                         .arg(mInserter.lastError().nativeErrorCode())

                         .arg(mInserter.lastError().driverText()) );

    }

    newRow();

}

QString Output::wikiFormat() const

{

    QString result=QString("!!%1\nTable Name: %2\n%3\n\n").arg(name(), tableName(), description());

    // loop over columns...

    result += "||__caption__|__datatype__|__description__\n"; // table begin

    foreach(const OutputColumn &col, mColumns)

        result+=QString("%1|%2|%3\n").arg(col.name(), col.datatype(), col.description());

    result[result.length()-1]=' '; // clear last newline

    result+="||\n";

    return result;

}