C++ QString::capacity方法代码示例

void WdgAddStation::OnSave()
{
	QString Str = ui.leComment->text();
	if(Str.capacity()<1)
		return;
	if(ui.sbFreq->value() > 100000 && ui.sbFreq->value() < 440000000)
	{
		emit Station(ui.leComment->text(), ui.sbFreq->value(), ui.comboBox->currentIndex());
		close();
	}
}

QString KexiDB::escapeBLOB(const QByteArray& array, BLOBEscapingType type)
{
    const int size = array.size();
    if (size == 0)
        return QString();
    int escaped_length = size * 2;
    if (type == BLOBEscape0xHex || type == BLOBEscapeOctal)
        escaped_length += 2/*0x or X'*/;
    else if (type == BLOBEscapeXHex)
        escaped_length += 3; //X' + '
    QString str;
    str.reserve(escaped_length);
    if (str.capacity() < escaped_length) {
        KexiDBWarn << "KexiDB::Driver::escapeBLOB(): no enough memory (cannot allocate " <<
        escaped_length << " chars)";
        return QString();
    }
    if (type == BLOBEscapeXHex)
        str = QString::fromLatin1("X'");
    else if (type == BLOBEscape0xHex)
        str = QString::fromLatin1("0x");
    else if (type == BLOBEscapeOctal)
        str = QString::fromLatin1("'");

    int new_length = str.length(); //after X' or 0x, etc.
    if (type == BLOBEscapeOctal) {
        // only escape nonprintable characters as in Table 8-7:
        // http://www.postgresql.org/docs/8.1/interactive/datatype-binary.html
        // i.e. escape for bytes: < 32, >= 127, 39 ('), 92(\).
        for (int i = 0; i < size; i++) {
            const unsigned char val = array[i];
            if (val < 32 || val >= 127 || val == 39 || val == 92) {
                str[new_length++] = '\\';
                str[new_length++] = '\\';
                str[new_length++] = '0' + val / 64;
                str[new_length++] = '0' + (val % 64) / 8;
                str[new_length++] = '0' + val % 8;
            } else {
                str[new_length++] = val;
            }
        }
    } else {
        for (int i = 0; i < size; i++) {
            const unsigned char val = array[i];
            str[new_length++] = (val / 16) < 10 ? ('0' + (val / 16)) : ('A' + (val / 16) - 10);
            str[new_length++] = (val % 16) < 10 ? ('0' + (val % 16)) : ('A' + (val % 16) - 10);
        }
    }
    if (type == BLOBEscapeXHex || type == BLOBEscapeOctal)
        str[new_length++] = '\'';
    return str;
}

void MainWindow::on_pushButton_4_clicked()
{
     QTextDocument doc;
     QString txt;
     txt = ::textAt(h3,65,"ASAP Film Order") %
                  ::textAt(h3,40,"From C&C Special Products Co. 952-881-0073") %
                  ::textAt(h3,67,"Mark  Robin") %
                  ::textAt(h3,6,"Attn: Customer Service") % ::nbsp(63) % "Rip Settings:"%
                  ::textAt(h3,103,"1) Film Positives") %
                  ::textAt(h3,103,"2) DO NOT TRAP") %
                  ::textAt(h3,103,"3) Send Pre Separated") %
                  ::textAt(h3,6,"Date: " % ui->dateEdit->text()) %
                  ::textAt(h3,6,"File Name: " % ui->lineEdit_2->text());

qDebug() << "The memory used is: " << txt.capacity();

     doc.setHtml(txt);


     #if !defined(QT_NO_PRINTER) && !defined(QT_NO_PRINTDIALOG)
         QPrinter printer(QPrinter::HighResolution);
         QPrintDialog *dlg = new QPrintDialog(&printer, this);
         dlg->addEnabledOption(QAbstractPrintDialog::PrintSelection);
         dlg->setWindowTitle(tr("Print Document"));
         if (dlg->exec() == QDialog::Accepted)
            {
             QPrinter printer;
       //      printer.setOutputFileName("c:\\temp\\filenew.pdf");
       //      printer.setOutputFormat(QPrinter::PdfFormat);
             qDebug() <<  "Sending to printer";

             doc.print(&printer);
             printer.newPage();
             printer.setOutputFileName("c:\\temp\\faxASAP.pdf");
             printer.setOutputFormat(QPrinter::PdfFormat);
             qDebug() <<  "Creating PDF";
            doc.print(&printer);
             printer.newPage();

           }

         delete dlg;
     #endif

}

bool QMakeParser::read(ProFile *pro, const QString &in, int line, SubGrammar grammar)
{
    m_proFile = pro;
    m_lineNo = line;

    // Final precompiled token stream buffer
    QString tokBuff;
    // Worst-case size calculations:
    // - line marker adds 1 (2-nl) to 1st token of each line
    // - empty assignment "A=":2 =>
    //   TokHashLiteral(1) + hash(2) + len(1) + "A"(1) + TokAssign(1) + 0(1) +
    //   TokValueTerminator(1) == 8 (9)
    // - non-empty assignment "A=B C":5 =>
    //   TokHashLiteral(1) + hash(2) + len(1) + "A"(1) + TokAssign(1) + 2(1) +
    //   TokLiteral(1) + len(1) + "B"(1) +
    //   TokLiteral(1) + len(1) + "C"(1) + TokValueTerminator(1) == 14 (15)
    // - variable expansion: "$$f":3 =>
    //   TokVariable(1) + hash(2) + len(1) + "f"(1) = 5
    // - function expansion: "$$f()":5 =>
    //   TokFuncName(1) + hash(2) + len(1) + "f"(1) + TokFuncTerminator(1) = 6
    // - scope: "X:":2 =>
    //   TokHashLiteral(1) + hash(2) + len(1) + "A"(1) + TokCondition(1) +
    //   TokBranch(1) + len(2) + ... + len(2) + ... == 10
    // - test: "X():":4 =>
    //   TokHashLiteral(1) + hash(2) + len(1) + "A"(1) + TokTestCall(1) + TokFuncTerminator(1) +
    //   TokBranch(1) + len(2) + ... + len(2) + ... == 11
    // - "for(A,B):":9 =>
    //   TokForLoop(1) + hash(2) + len(1) + "A"(1) +
    //   len(2) + TokLiteral(1) + len(1) + "B"(1) + TokValueTerminator(1) +
    //   len(2) + ... + TokTerminator(1) == 14 (15)
    tokBuff.reserve((in.size() + 1) * 5);
    ushort *tokPtr = (ushort *)tokBuff.constData(); // Current writing position

    // Expression precompiler buffer.
    QString xprBuff;
    xprBuff.reserve(tokBuff.capacity()); // Excessive, but simple
    ushort *buf = (ushort *)xprBuff.constData();

    // Parser state
    m_blockstack.clear();
    m_blockstack.resize(1);

    QStack<ParseCtx> xprStack;
    xprStack.reserve(10);

    // We rely on QStrings being null-terminated, so don't maintain a global end pointer.
    const ushort *cur = (const ushort *)in.unicode();
    m_canElse = false;
  freshLine:
    m_state = StNew;
    m_invert = false;
    m_operator = NoOperator;
    m_markLine = m_lineNo;
    m_inError = false;
    int parens = 0; // Braces in value context
    int argc = 0;
    int wordCount = 0; // Number of words in currently accumulated expression
    int lastIndent = 0; // Previous line's indentation, to detect accidental continuation abuse
    bool lineMarked = true; // For in-expression markers
    ushort needSep = TokNewStr; // Met unquoted whitespace
    ushort quote = 0;
    ushort term = 0;

    Context context;
    ushort *ptr;
    if (grammar == ValueGrammar) {
        context = CtxPureValue;
        ptr = tokPtr + 2;
    } else {
        context = CtxTest;
        ptr = buf + 4;
    }
    ushort *xprPtr = ptr;

#define FLUSH_LHS_LITERAL() \
    do { \
        if ((tlen = ptr - xprPtr)) { \
            finalizeHashStr(xprPtr, tlen); \
            if (needSep) { \
                wordCount++; \
                needSep = 0; \
            } \
        } else { \
            ptr -= 4; \
        } \
    } while (0)

#define FLUSH_RHS_LITERAL() \
    do { \
        if ((tlen = ptr - xprPtr)) { \
            xprPtr[-2] = TokLiteral | needSep; \
            xprPtr[-1] = tlen; \
            if (needSep) { \
                wordCount++; \
                needSep = 0; \
            } \
        } else { \
            ptr -= 2; \
        } \
    } while (0)
//.........这里部分代码省略.........

bool KexiCSVExport::exportData(KDbTableOrQuerySchema *tableOrQuery,
                               const Options& options, int recordCount, QTextStream *predefinedTextStream)
{
    KDbConnection* conn = tableOrQuery->connection();
    if (!conn)
        return false;

    KDbQuerySchema* query = tableOrQuery->query();
    QList<QVariant> queryParams;
    if (!query) {
        query = tableOrQuery->table()->query();
    }
    else {
        queryParams = KexiMainWindowIface::global()->currentParametersForQuery(query->id());
    }

    if (recordCount == -1)
        recordCount = KDb::recordCount(tableOrQuery, queryParams);
    if (recordCount == -1)
        return false;

//! @todo move this to non-GUI location so it can be also used via command line
//! @todo add a "finish" page with a progressbar.
//! @todo look at recordCount whether the data is really large;
//!       if so: avoid copying to clipboard (or ask user) because of system memory

//! @todo OPTIMIZATION: use fieldsExpanded(true /*UNIQUE*/)
//! @todo OPTIMIZATION? (avoid multiple data retrieving) look for already fetched data within KexiProject..

    KDbQueryColumnInfo::Vector fields(query->fieldsExpanded(KDbQuerySchema::WithInternalFields));
    QString buffer;

    QScopedPointer<QSaveFile> kSaveFile;
    QTextStream *stream = 0;
    QScopedPointer<QTextStream> kSaveFileTextStream;

    const bool copyToClipboard = options.mode == Clipboard;
    if (copyToClipboard) {
//! @todo (during exporting): enlarge bufSize by factor of 2 when it became too small
        int bufSize = qMin((recordCount < 0 ? 10 : recordCount) * fields.count() * 20, 128000);
        buffer.reserve(bufSize);
        if (buffer.capacity() < bufSize) {
            qWarning() << "Cannot allocate memory for " << bufSize
            << " characters";
            return false;
        }
    } else {
        if (predefinedTextStream) {
            stream = predefinedTextStream;
        } else {
            if (options.fileName.isEmpty()) {//sanity
                qWarning() << "Fname is empty";
                return false;
            }
            kSaveFile.reset(new QSaveFile(options.fileName));

            qDebug() << "QSaveFile Filename:" << kSaveFile->fileName();

            if (kSaveFile->open(QIODevice::WriteOnly)) {
                kSaveFileTextStream.reset(new QTextStream(kSaveFile.data()));
                stream = kSaveFileTextStream.data();
                qDebug() << "have a stream";
            }
            if (QFileDevice::NoError != kSaveFile->error() || !stream) {//sanity
                qWarning() << "Status != 0 or stream == 0";
//! @todo show error
                return false;
            }
        }
    }

//! @todo escape strings

#define _ERR \
    if (kSaveFile) { kSaveFile->cancelWriting(); } \
    return false

#define APPEND(what) \
    if (copyToClipboard) buffer.append(what); else (*stream) << (what)

// use native line ending for copying, RFC 4180 one for saving to file
#define APPEND_EOLN \
    if (copyToClipboard) { APPEND('\n'); } else { APPEND("\r\n"); }

    qDebug() << 0 << "Columns: " << query->fieldsExpanded().count();
    // 0. Cache information
    const int fieldsCount = query->fieldsExpanded().count(); //real fields count without internals
    const QByteArray delimiter(options.delimiter.left(1).toLatin1());
    const bool hasTextQuote = !options.textQuote.isEmpty();
    const QString textQuote(options.textQuote.left(1));
    const QByteArray escapedTextQuote((textQuote + textQuote).toLatin1());   //ok?
    //cache for faster checks
    QScopedArrayPointer<bool> isText(new bool[fieldsCount]);
    QScopedArrayPointer<bool> isDateTime(new bool[fieldsCount]);
    QScopedArrayPointer<bool> isTime(new bool[fieldsCount]);
    QScopedArrayPointer<bool> isBLOB(new bool[fieldsCount]);
    QScopedArrayPointer<int> visibleFieldIndex(new int[fieldsCount]);
// bool isInteger[fieldsCount]; //cache for faster checks
// bool isFloatingPoint[fieldsCount]; //cache for faster checks
    for (int i = 0; i < fieldsCount; i++) {
//.........这里部分代码省略.........