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/****************************************************************************
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**
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** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
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** All rights reserved.
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** Contact: Nokia Corporation (qt-info@nokia.com)
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**
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** This file is part of the QtCore module of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:LGPL$
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** No Commercial Usage
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** This file contains pre-release code and may not be distributed.
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** You may use this file in accordance with the terms and conditions
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** contained in the Technology Preview License Agreement accompanying
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** this package.
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**
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** GNU Lesser General Public License Usage
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** Alternatively, this file may be used under the terms of the GNU Lesser
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** General Public License version 2.1 as published by the Free Software
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** Foundation and appearing in the file LICENSE.LGPL included in the
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** packaging of this file. Please review the following information to
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** ensure the GNU Lesser General Public License version 2.1 requirements
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** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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**
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** In addition, as a special exception, Nokia gives you certain additional
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** rights. These rights are described in the Nokia Qt LGPL Exception
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** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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**
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** If you have questions regarding the use of this file, please contact
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** Nokia at qt-info@nokia.com.
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**
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**
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**
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**
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**
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**
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**
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**
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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#include "qbuffer.h"
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#include "private/qiodevice_p.h"
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QT_BEGIN_NAMESPACE
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/** QBufferPrivate **/
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class QBufferPrivate : public QIODevicePrivate
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{
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Q_DECLARE_PUBLIC(QBuffer)
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public:
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QBufferPrivate()
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: buf(0)
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#ifndef QT_NO_QOBJECT
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, writtenSinceLastEmit(0), signalConnectionCount(0), signalsEmitted(false)
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#endif
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{ }
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~QBufferPrivate() { }
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QByteArray *buf;
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QByteArray defaultBuf;
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int ioIndex;
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#ifndef QT_NO_QOBJECT
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// private slots
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void _q_emitSignals();
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qint64 writtenSinceLastEmit;
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int signalConnectionCount;
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bool signalsEmitted;
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#endif
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};
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#ifndef QT_NO_QOBJECT
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void QBufferPrivate::_q_emitSignals()
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{
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Q_Q(QBuffer);
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emit q->bytesWritten(writtenSinceLastEmit);
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writtenSinceLastEmit = 0;
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emit q->readyRead();
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signalsEmitted = false;
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}
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#endif
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/*!
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\class QBuffer
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\reentrant
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\brief The QBuffer class provides a QIODevice interface for a QByteArray.
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\ingroup io
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QBuffer allows you to access a QByteArray using the QIODevice
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interface. The QByteArray is treated just as a standard random-accessed
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file. Example:
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\snippet doc/src/snippets/buffer/buffer.cpp 0
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By default, an internal QByteArray buffer is created for you when
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you create a QBuffer. You can access this buffer directly by
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calling buffer(). You can also use QBuffer with an existing
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QByteArray by calling setBuffer(), or by passing your array to
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QBuffer's constructor.
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Call open() to open the buffer. Then call write() or
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putChar() to write to the buffer, and read(), readLine(),
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readAll(), or getChar() to read from it. size() returns the
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current size of the buffer, and you can seek to arbitrary
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positions in the buffer by calling seek(). When you are done with
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accessing the buffer, call close().
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The following code snippet shows how to write data to a
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QByteArray using QDataStream and QBuffer:
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\snippet doc/src/snippets/buffer/buffer.cpp 1
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Effectively, we convert the application's QPalette into a byte
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array. Here's how to read the data from the QByteArray:
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\snippet doc/src/snippets/buffer/buffer.cpp 2
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QTextStream and QDataStream also provide convenience constructors
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that take a QByteArray and that create a QBuffer behind the
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scenes.
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QBuffer emits readyRead() when new data has arrived in the
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buffer. By connecting to this signal, you can use QBuffer to
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store temporary data before processing it. For example, you can
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pass the buffer to QFtp when downloading a file from an FTP
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server. Whenever a new payload of data has been downloaded,
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readyRead() is emitted, and you can process the data that just
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arrived. QBuffer also emits bytesWritten() every time new data
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has been written to the buffer.
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\sa QFile, QDataStream, QTextStream, QByteArray
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*/
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#ifdef QT_NO_QOBJECT
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QBuffer::QBuffer()
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: QIODevice(*new QBufferPrivate)
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{
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Q_D(QBuffer);
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d->buf = &d->defaultBuf;
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d->ioIndex = 0;
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}
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QBuffer::QBuffer(QByteArray *buf)
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: QIODevice(*new QBufferPrivate)
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{
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Q_D(QBuffer);
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d->buf = buf ? buf : &d->defaultBuf;
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d->ioIndex = 0;
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d->defaultBuf.clear();
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}
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#else
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/*!
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Constructs an empty buffer with the given \a parent. You can call
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setData() to fill the buffer with data, or you can open it in
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write mode and use write().
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\sa open()
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*/
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QBuffer::QBuffer(QObject *parent)
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: QIODevice(*new QBufferPrivate, parent)
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{
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Q_D(QBuffer);
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d->buf = &d->defaultBuf;
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d->ioIndex = 0;
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}
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/*!
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Constructs a QBuffer that uses the QByteArray pointed to by \a
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byteArray as its internal buffer, and with the given \a parent.
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The caller is responsible for ensuring that \a byteArray remains
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valid until the QBuffer is destroyed, or until setBuffer() is
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called to change the buffer. QBuffer doesn't take ownership of
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the QByteArray.
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If you open the buffer in write-only mode or read-write mode and
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write something into the QBuffer, \a byteArray will be modified.
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Example:
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\snippet doc/src/snippets/buffer/buffer.cpp 3
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\sa open(), setBuffer(), setData()
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*/
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QBuffer::QBuffer(QByteArray *byteArray, QObject *parent)
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: QIODevice(*new QBufferPrivate, parent)
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{
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Q_D(QBuffer);
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d->buf = byteArray ? byteArray : &d->defaultBuf;
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d->defaultBuf.clear();
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d->ioIndex = 0;
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}
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#endif
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/*!
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Destroys the buffer.
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*/
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QBuffer::~QBuffer()
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{
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}
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/*!
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Makes QBuffer uses the QByteArray pointed to by \a
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byteArray as its internal buffer. The caller is responsible for
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ensuring that \a byteArray remains valid until the QBuffer is
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destroyed, or until setBuffer() is called to change the buffer.
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QBuffer doesn't take ownership of the QByteArray.
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Does nothing if isOpen() is true.
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If you open the buffer in write-only mode or read-write mode and
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write something into the QBuffer, \a byteArray will be modified.
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Example:
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\snippet doc/src/snippets/buffer/buffer.cpp 4
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If \a byteArray is 0, the buffer creates its own internal
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QByteArray to work on. This byte array is initially empty.
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\sa buffer(), setData(), open()
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*/
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void QBuffer::setBuffer(QByteArray *byteArray)
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{
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Q_D(QBuffer);
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if (isOpen()) {
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qWarning("QBuffer::setBuffer: Buffer is open");
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return;
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}
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if (byteArray) {
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d->buf = byteArray;
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} else {
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d->buf = &d->defaultBuf;
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}
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d->defaultBuf.clear();
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d->ioIndex = 0;
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}
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/*!
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Returns a reference to the QBuffer's internal buffer. You can use
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it to modify the QByteArray behind the QBuffer's back.
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\sa setBuffer(), data()
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*/
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QByteArray &QBuffer::buffer()
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{
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Q_D(QBuffer);
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return *d->buf;
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}
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/*!
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\overload
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This is the same as data().
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*/
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const QByteArray &QBuffer::buffer() const
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{
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Q_D(const QBuffer);
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return *d->buf;
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}
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/*!
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Returns the data contained in the buffer.
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This is the same as buffer().
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\sa setData(), setBuffer()
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*/
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const QByteArray &QBuffer::data() const
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{
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Q_D(const QBuffer);
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return *d->buf;
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}
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/*!
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Sets the contents of the internal buffer to be \a data. This is
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the same as assigning \a data to buffer().
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Does nothing if isOpen() is true.
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\sa setBuffer()
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*/
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void QBuffer::setData(const QByteArray &data)
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{
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Q_D(QBuffer);
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if (isOpen()) {
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qWarning("QBuffer::setData: Buffer is open");
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return;
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}
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*d->buf = data;
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d->ioIndex = 0;
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}
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/*!
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\fn void QBuffer::setData(const char *data, int size)
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\overload
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Sets the contents of the internal buffer to be the first \a size
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bytes of \a data.
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*/
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/*!
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\reimp
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*/
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bool QBuffer::open(OpenMode flags)
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{
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Q_D(QBuffer);
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if ((flags & Append) == Append)
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flags |= WriteOnly;
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setOpenMode(flags);
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if (!(isReadable() || isWritable())) {
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qWarning("QFile::open: File access not specified");
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return false;
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}
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if ((flags & QIODevice::Truncate) == QIODevice::Truncate) {
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d->buf->resize(0);
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}
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if ((flags & QIODevice::Append) == QIODevice::Append) // append to end of buffer
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seek(d->buf->size());
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else
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seek(0);
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return true;
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}
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/*!
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\reimp
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*/
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void QBuffer::close()
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{
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QIODevice::close();
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}
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/*!
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\reimp
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*/
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qint64 QBuffer::pos() const
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{
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return QIODevice::pos();
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}
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/*!
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\reimp
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*/
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qint64 QBuffer::size() const
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{
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Q_D(const QBuffer);
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return qint64(d->buf->size());
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}
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/*!
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\reimp
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*/
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bool QBuffer::seek(qint64 pos)
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{
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Q_D(QBuffer);
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if (pos > d->buf->size() && isWritable()) {
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if (seek(d->buf->size())) {
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const qint64 gapSize = pos - d->buf->size();
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if (write(QByteArray(gapSize, 0)) != gapSize) {
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qWarning("QBuffer::seek: Unable to fill gap");
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return false;
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}
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} else {
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return false;
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|
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}
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} else if (pos > d->buf->size() || pos < 0) {
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qWarning("QBuffer::seek: Invalid pos: %d", int(pos));
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return false;
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}
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d->ioIndex = int(pos);
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return QIODevice::seek(pos);
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}
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/*!
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\reimp
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*/
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bool QBuffer::atEnd() const
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{
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return QIODevice::atEnd();
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}
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/*!
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\reimp
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*/
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bool QBuffer::canReadLine() const
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{
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Q_D(const QBuffer);
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if (!isOpen())
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return false;
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return d->buf->indexOf('\n', int(pos())) != -1 || QIODevice::canReadLine();
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}
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406 |
/*!
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\reimp
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|
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*/
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qint64 QBuffer::readData(char *data, qint64 len)
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{
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Q_D(QBuffer);
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if ((len = qMin(len, qint64(d->buf->size()) - d->ioIndex)) <= 0)
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return qint64(0);
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|
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memcpy(data, d->buf->constData() + d->ioIndex, len);
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|
415 |
d->ioIndex += int(len);
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416 |
return len;
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|
417 |
}
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|
418 |
|
|
419 |
/*!
|
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420 |
\reimp
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|
421 |
*/
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qint64 QBuffer::writeData(const char *data, qint64 len)
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423 |
{
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Q_D(QBuffer);
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int extraBytes = d->ioIndex + len - d->buf->size();
|
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426 |
if (extraBytes > 0) { // overflow
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|
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int newSize = d->buf->size() + extraBytes;
|
|
428 |
d->buf->resize(newSize);
|
|
429 |
if (d->buf->size() != newSize) { // could not resize
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|
430 |
qWarning("QBuffer::writeData: Memory allocation error");
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|
431 |
return -1;
|
|
432 |
}
|
|
433 |
}
|
|
434 |
|
|
435 |
memcpy(d->buf->data() + d->ioIndex, (uchar *)data, int(len));
|
|
436 |
d->ioIndex += int(len);
|
|
437 |
|
|
438 |
#ifndef QT_NO_QOBJECT
|
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439 |
d->writtenSinceLastEmit += len;
|
|
440 |
if (d->signalConnectionCount && !d->signalsEmitted && !signalsBlocked()) {
|
|
441 |
d->signalsEmitted = true;
|
|
442 |
QMetaObject::invokeMethod(this, "_q_emitSignals", Qt::QueuedConnection);
|
|
443 |
}
|
|
444 |
#endif
|
|
445 |
return len;
|
|
446 |
}
|
|
447 |
|
|
448 |
#ifndef QT_NO_QOBJECT
|
|
449 |
/*!
|
|
450 |
\reimp
|
|
451 |
\internal
|
|
452 |
*/
|
|
453 |
void QBuffer::connectNotify(const char *signal)
|
|
454 |
{
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|
455 |
if (strcmp(signal + 1, "readyRead()") == 0 || strcmp(signal + 1, "bytesWritten(qint64)") == 0)
|
|
456 |
d_func()->signalConnectionCount++;
|
|
457 |
}
|
|
458 |
|
|
459 |
/*!
|
|
460 |
\reimp
|
|
461 |
\internal
|
|
462 |
*/
|
|
463 |
void QBuffer::disconnectNotify(const char *signal)
|
|
464 |
{
|
|
465 |
if (!signal || strcmp(signal + 1, "readyRead()") == 0 || strcmp(signal + 1, "bytesWritten(qint64)") == 0)
|
|
466 |
d_func()->signalConnectionCount--;
|
|
467 |
}
|
|
468 |
#endif
|
|
469 |
|
|
470 |
QT_END_NAMESPACE
|
|
471 |
|
|
472 |
#ifndef QT_NO_QOBJECT
|
|
473 |
# include "moc_qbuffer.cpp"
|
|
474 |
#endif
|
|
475 |
|