qtextstream.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

    qDebug("QTextStreamPrivate::fillReadBuffer(), device->read(\"%s\", %d) == %d",
           qt_prettyDebug(buf, qMin(32,int(bytesRead)) , int(bytesRead)).constData(), sizeof(buf), int(bytesRead));
#endif
    if (bytesRead <= 0)
        return false;

#ifndef QT_NO_TEXTCODEC
    // codec auto detection, explicitly defaults to locale encoding if
    // the codec has been set to 0.
    if (!codec || autoDetectUnicode) {
        autoDetectUnicode = false;
        if (bytesRead >= 2 && (uchar(buf[0]) == 0xff && uchar(buf[1]) == 0xfe
                               || uchar(buf[0]) == 0xfe && uchar(buf[1]) == 0xff)) {
            codec = QTextCodec::codecForName("UTF-16");
        } else if (!codec) {
            codec = QTextCodec::codecForLocale();
            writeConverterState.flags |= QTextCodec::IgnoreHeader;
        }
    }
#endif
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStreamPrivate::fillReadBuffer(), using %s codec",
           codec->name().constData());
#endif

    readBuffer += endOfBufferState;
#ifndef QT_NO_TEXTCODEC
    // convert to unicode
    readBuffer += codec->toUnicode(buf, bytesRead, &readConverterState);
#else
    readBuffer += QString(QByteArray(buf, bytesRead));
#endif

    // reset the Text flag.
    if (textModeEnabled) {
        device->setTextModeEnabled(true);
        readBuffer.replace(QLatin1String("\r\n"), QLatin1String("\n"));
        if (readBuffer.endsWith(QLatin1Char('\r')) && !device->atEnd()) {
            endOfBufferState = QLatin1String("\r");
            readBuffer.chop(1);
        } else {
            endOfBufferState.clear();
        }
    }

#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStreamPrivate::fillReadBuffer() read %d bytes from device", int(bytesRead));
#endif
    return true;
}

/*! \internal
*/
bool QTextStreamPrivate::flushWriteBuffer()
{
    // no buffer next to the QString itself; this function should only
    // be called internally, for devices.
    if (string || !device)
        return false;
    if (writeBuffer.isEmpty())
        return true;

#if defined (Q_OS_WIN)
    // handle text translation and bypass the Text flag in the device.
    bool textModeEnabled = device->isTextModeEnabled();
    if (textModeEnabled) {
        device->setTextModeEnabled(false);
        writeBuffer.replace(QLatin1Char('\n'), QLatin1String("\r\n"));
    }
#endif

#ifndef QT_NO_TEXTCODEC
    if (!codec)
        codec = QTextCodec::codecForLocale();
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStreamPrivate::flushWriteBuffer(), using %s codec (%s generating BOM)",
           codec->name().constData(), writeConverterState.flags & QTextCodec::IgnoreHeader ? "not" : "");
#endif

    // convert from unicode to raw data
    QByteArray data = codec->fromUnicode(writeBuffer.data(), writeBuffer.size(), &writeConverterState);
#else
    QByteArray data = writeBuffer.toLocal8Bit();
#endif
    writeBuffer.clear();

    // write raw data to the device
    qint64 bytesWritten = device->write(data);
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStreamPrivate::flushWriteBuffer(), device->write(\"%s\") == %d",
           qt_prettyDebug(data.constData(), qMin(data.size(),32), data.size()).constData(), int(bytesWritten));
#endif
    if (bytesWritten <= 0)
        return false;

#if defined (Q_OS_WIN)
    // replace the text flag
    if (textModeEnabled)
        device->setTextModeEnabled(true);
#endif

    // flush the file
#ifndef QT_NO_QOBJECT
    QFile *file = qobject_cast<QFile *>(device);
    bool flushed = file && file->flush();
#else
    bool flushed = true;
#endif

#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStreamPrivate::flushWriteBuffer() wrote %d bytes",
           int(bytesWritten));
#endif
    return flushed && bytesWritten == qint64(data.size());
}

/*! \internal

    Scans no more than \a maxlen QChars in the current buffer for the
    first \a delimiter. Stores a pointer to the start offset of the
    token in \a ptr, and the length in QChars in \a length.
*/
bool QTextStreamPrivate::scan(const QChar **ptr, int *length, int maxlen, TokenDelimiter delimiter)
{
    int totalSize = 0;
    int delimSize = 0;
    bool consumeDelimiter = false;
    bool foundToken = false;
    int startOffset = device ? readBufferOffset : stringOffset;
    QChar lastChar;

    bool canStillReadFromDevice = true;
    do {
        int endOffset;
        const QChar *chPtr;
        if (device) {
            chPtr = readBuffer.constData();
            endOffset = readBuffer.size();
        } else {
            chPtr = string->constData();
            endOffset = string->size();
        }
        chPtr += startOffset;

        for (; !foundToken && startOffset < endOffset && (!maxlen || totalSize < maxlen); ++startOffset) {
            const QChar ch = *chPtr++;
            ++totalSize;

            if (delimiter == Space && ch.isSpace()) {
                foundToken = true;
                delimSize = 1;
            } else if (delimiter == NotSpace && !ch.isSpace()) {
                foundToken = true;
                delimSize = 1;
            } else if (delimiter == EndOfLine && ch == QLatin1Char('\n')) {
                foundToken = true;
                delimSize = (lastChar == QLatin1Char('\r')) ? 2 : 1;
                consumeDelimiter = true;
            }

            lastChar = ch;
        }
    } while (!foundToken
             && (!maxlen || totalSize < maxlen)
             && (device && (canStillReadFromDevice = fillReadBuffer())));

    // if the token was not found, but we reached the end of input,
    // then we accept what we got. if we are not at the end of input,
    // we return false.
    if (!foundToken && (!maxlen || totalSize < maxlen)
        && (totalSize == 0
            || (string && stringOffset + totalSize < string->size())
            || (device && !device->atEnd() && canStillReadFromDevice))) {
#if defined (QTEXTSTREAM_DEBUG)
        qDebug("QTextStreamPrivate::scan() did not find the token.");
#endif
        return false;
    }

    // if we find a '\r' at the end of the data when reading lines,
    // don't make it part of the line.
    if (totalSize > 0 && !foundToken && delimiter == EndOfLine) {
        if (((string && stringOffset + totalSize == string->size()) || (device && device->atEnd()))
            && lastChar == QLatin1Char('\r')) {
            consumeDelimiter = true;
            ++delimSize;
        }
    }

    // set the read offset and length of the token
    if (length)
        *length = totalSize - delimSize;
    if (ptr)
        *ptr = readPtr();

    // update last token size. the callee will call consumeLastToken() when
    // done.
    lastTokenSize = totalSize;
    if (!consumeDelimiter)
        lastTokenSize -= delimSize;

#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStreamPrivate::scan(%p, %p, %d, %x) token length = %d, delimiter = %d",
           ptr, length, maxlen, (int)delimiter, totalSize - delimSize, delimSize);
#endif
    return true;
}

/*! \internal
*/
inline const QChar *QTextStreamPrivate::readPtr() const
{
    Q_ASSERT(readBufferOffset <= readBuffer.size());
    if (string)
        return string->constData() + stringOffset;
    return readBuffer.constData() + readBufferOffset;
}

/*! \internal
*/
inline void QTextStreamPrivate::consumeLastToken()
{
    if (lastTokenSize)
        consume(lastTokenSize);
    lastTokenSize = 0;
}

/*! \internal
*/
inline void QTextStreamPrivate::consume(int size)
{
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStreamPrivate::consume(%d)", size);
#endif
    if (string) {
        stringOffset += size;
        if (stringOffset > string->size())
            stringOffset = string->size();
    } else {
        readBufferOffset += size;
        if (readBufferOffset >= readBuffer.size()) {
            readBufferOffset = 0;
            readBuffer.clear();
        }
    }
}

/*! \internal
*/
inline bool QTextStreamPrivate::write(const QString &data)
{
    if (string) {
        string->append(data);
    } else {
        writeBuffer += data;
        if (writeBuffer.size() > QTEXTSTREAM_BUFFERSIZE)
            return flushWriteBuffer();
    }
    return true;
}

/*! \internal
*/
inline bool QTextStreamPrivate::getChar(QChar *ch)
{
    if ((string && stringOffset == string->size())
        || (device && readBuffer.isEmpty() && !fillReadBuffer())) {
        if (ch)
            *ch = 0;
        return false;
    }
    if (ch)
        *ch = *readPtr();
    consume(1);
    return true;
}

/*! \internal
*/
inline void QTextStreamPrivate::ungetChar(const QChar &ch)
{
    if (string) {
        if (stringOffset == 0)
            string->prepend(ch);
        else
            (*string)[--stringOffset] = ch;
        return;
    }

    if (readBufferOffset == 0) {
        readBuffer.prepend(ch);
        return;
    }

    readBuffer[--readBufferOffset] = ch;
}

/*! \internal
*/
inline bool QTextStreamPrivate::putString(const QString &s)
{
    QString tmp = s;

    // handle padding
    int padSize = fieldWidth - s.size();
    if (padSize > 0) {
        QString pad(padSize > 0 ? padSize : 0, padChar);
        if (fieldAlignment == QTextStream::AlignLeft) {
            tmp.append(QString(padSize, padChar));
        } else if (fieldAlignment == QTextStream::AlignRight) {
            tmp.prepend(QString(padSize, padChar));
        } else if (fieldAlignment == QTextStream::AlignCenter) {
            tmp.prepend(QString(padSize/2, padChar));
            tmp.append(QString(padSize - padSize/2, padChar));
        }
    }

#if defined (QTEXTSTREAM_DEBUG)
    QByteArray a = s.toUtf8();
    QByteArray b = tmp.toUtf8();
    qDebug("QTextStreamPrivate::putString(\"%s\") calls write(\"%s\")",
           qt_prettyDebug(a.constData(), a.size(), qMax(16, a.size())).constData(),
           qt_prettyDebug(b.constData(), b.size(), qMax(16, b.size())).constData());
#endif
    return write(tmp);
}

/*!
    Constructs a QTextStream. Before you can use it for reading or
    writing, you must assign a device or a string.

    \sa setDevice(), setString()
*/
QTextStream::QTextStream()
    : d_ptr(new QTextStreamPrivate(this))
{
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStream::QTextStream()");
#endif
    Q_D(QTextStream);
    d->status = Ok;
}

/*!
    Constructs a QTextStream that operates on \a device.
*/
QTextStream::QTextStream(QIODevice *device)
    : d_ptr(new QTextStreamPrivate(this))
{
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStream::QTextStream(QIODevice *device == *%p)",
           device);
#endif
    Q_D(QTextStream);
    d->device = device;
#ifndef QT_NO_QOBJECT
    d->deviceClosedNotifier.setupDevice(this, d->device);
#endif
    d->status = Ok;
}

/*!
    Constructs a QTextStream that operates on \a string, using \a
    openMode to define the open mode.
*/
QTextStream::QTextStream(QString *string, QIODevice::OpenMode openMode)
    : d_ptr(new QTextStreamPrivate(this))
{
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStream::QTextStream(QString *string == *%p, openMode = %d)",
           string, int(openMode));
#endif
    Q_D(QTextStream);
    d->string = string;
    d->stringOpenMode = openMode;
    d->status = Ok;
}

/*!
    Constructs a QTextStream that operates on \a array, using \a
    openMode to define the open mode. Internally, the array is wrapped
    by a QBuffer.
*/
QTextStream::QTextStream(QByteArray *array, QIODevice::OpenMode openMode)
    : d_ptr(new QTextStreamPrivate(this))
{
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStream::QTextStream(QByteArray *array == *%p, openMode = %d)",
           array, int(openMode));
#endif
    Q_D(QTextStream);
    d->device = new QBuffer(array);
    d->device->open(openMode);
    d->deleteDevice = true;
#ifndef QT_NO_QOBJECT
    d->deviceClosedNotifier.setupDevice(this, d->device);
#endif
    d->status = Ok;
}

/*!
    Constructs a QTextStream that operates on \a array, using \a
    openMode to define the open mode. The array is accessed as
    read-only, regardless of the values in \a openMode.

    This constructor is convenient for working on constant
    strings. Example:

    \code
        int main(int argc, char *argv[])
        {
            // read numeric arguments (123, 0x20, 4.5...)
            for (int i = 1; i < argc; ++i) {
                  int number;
                  QTextStream in(argv[i]);
                  in >> number;
                  ...
            }
        }
    \endcode
*/
QTextStream::QTextStream(const QByteArray &array, QIODevice::OpenMode openMode)
    : d_ptr(new QTextStreamPrivate(this))
{
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStream::QTextStream(const QByteArray &array == *(%p), openMode = %d)",
           &array, int(openMode));
#endif
    QBuffer *buffer = new QBuffer;
    buffer->setData(array);
    buffer->open(openMode);

    Q_D(QTextStream);
    d->device = buffer;
    d->deleteDevice = true;
#ifndef QT_NO_QOBJECT
    d->deviceClosedNotifier.setupDevice(this, d->device);
#endif
    d->status = Ok;
}

/*!
    Constructs a QTextStream that operates on \a fileHandle, using \a
    openMode to define the open mode. Internally, a QFile is created
    to handle the FILE pointer.

    This constructor is useful for working directly with the common
    FILE based input and output streams: stdin, stdout and stderr. Example:

    \code
        QString str;
        QTextStream in(stdin);
        in >> str;
    \endcode
*/

QTextStream::QTextStream(FILE *fileHandle, QIODevice::OpenMode openMode)
    : d_ptr(new QTextStreamPrivate(this))
{
#if defined (QTEXTSTREAM_DEBUG)
    qDebug("QTextStream::QTextStream(FILE *fileHandle = %p, openMode = %d)",
           fileHandle, int(openMode));
#endif
    QFile *file = new QFile;
    file->open(fileHandle, openMode);

    Q_D(QTextStream);
    d->device = file;
    d->deleteDevice = true;
#ifndef QT_NO_QOBJECT
    d->deviceClosedNotifier.setupDevice(this, d->device);
#endif
    d->status = Ok;
}

/*!
    Destroys the QTextStream.

    If the stream operates on a device, flush() will be called
    implicitly. Otherwise, the device is unaffected.
*/
QTextStream::~QTextStream()
{
    Q_D(QTextStream);
#if defined (QTEXTSTREAM_DEBUG)