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authorMarkus Goetz <Markus.Goetz@nokia.com>2009-05-13 09:03:03 (GMT)
committerMarkus Goetz <Markus.Goetz@nokia.com>2009-05-13 11:42:04 (GMT)
commit78866bec190ca56f977d5a4b5130bbd3d2e8c412 (patch)
tree6fe17f70fdec8540c96470f611cc5c7f5bc711a7 /src/corelib/io/qnoncontiguousbytedevice.cpp
parent0076f04c3637aaebb4d70d7c7e5fd0a78527c260 (diff)
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QNonContiguousByteDevice: An wrapper around QByteArray, QIODevice, ...
New private class, needed for the rewrite of the upload side of QNetworkAccessManager. Allows to have a "byte pointer view" on stuff like QRingBuffer, QByteArray, QFile and any QIODevice. Reviewed-by: Thiago Macieira Reviewed-by: Peter Hartmann
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qnoncontiguousbytedevice_p.h"
+#include <QObject>
+#include <QBuffer>
+#include <QDebug>
+#include <QFile>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+ \class QNonContiguousByteDevice
+ \brief A QNonContiguousByteDevice is a representation of a
+ file, array or buffer that allows access with a read pointer.
+ \since 4.6
+
+ \inmodule QtCore
+
+ The goal of this class is to have a data representation that
+ allows us to avoid doing a memcpy as we have to do with QIODevice.
+
+ \sa QNonContiguousByteDeviceFactory
+
+ \internal
+*/
+/*!
+ \fn virtual const char* QNonContiguousByteDevice::readPointer(qint64 maximumLength, qint64 &len)
+
+ Return a byte pointer for at most \a maximumLength bytes of that device.
+ if \a maximumLength is -1, the caller does not care about the length and
+ the device may return what it desires to.
+ The actual number of bytes the pointer is valid for is returned in
+ the \a len variable.
+ \a len will be -1 if EOF or an error occurs.
+ If it was really EOF can then afterwards be checked with atEnd()
+ Returns 0 if it is not possible to read at that position.
+
+ \sa atEnd()
+
+ \internal
+*/
+/*!
+ \fn virtual bool QNonContiguousByteDevice::advanceReadPointer(qint64 amount)
+
+ will advance the internal read pointer by \a amount bytes.
+ The old readPointer is invalid after this call.
+
+ \sa readPointer()
+
+ \internal
+*/
+/*!
+ \fn virtual bool QNonContiguousByteDevice::atEnd()
+
+ Returns true if everything has been read and the read
+ pointer cannot be advanced anymore.
+
+ \sa readPointer(), advanceReadPointer(), reset()
+
+ \internal
+*/
+/*!
+ \fn virtual bool QNonContiguousByteDevice::reset()
+
+ Moves the internal read pointer back to the beginning.
+ Returns false if this was not possible.
+
+ \sa atEnd(), disableReset()
+
+ \internal
+*/
+/*!
+ \fn void QNonContiguousByteDevice::disableReset()
+
+ Disable the reset() call, e.g. it will always
+ do nothing and return false.
+
+ \sa reset()
+
+ \internal
+*/
+/*!
+ \fn virtual qint64 QNonContiguousByteDevice::size()
+
+ Returns the size of the complete device or -1 if unknown.
+ May also return less/more than what can be actually read with readPointer()
+
+ \internal
+*/
+/*!
+ \fn void QNonContiguousByteDevice::readyRead()
+
+ Emitted when there is data available
+
+ \internal
+*/
+/*!
+ \fn void QNonContiguousByteDevice::readProgress(qint64 current, qint64 total)
+
+ Emitted when data has been "read" by advancing the read pointer
+
+ \internal
+*/
+
+QNonContiguousByteDevice::QNonContiguousByteDevice() : QObject((QObject*)0), resetDisabled(false)
+{
+};
+
+QNonContiguousByteDevice::~QNonContiguousByteDevice()
+{
+};
+
+void QNonContiguousByteDevice::disableReset()
+{
+ resetDisabled = true;
+}
+
+QNonContiguousByteDeviceBufferImpl::QNonContiguousByteDeviceBufferImpl(QBuffer *b) : QNonContiguousByteDevice()
+{
+ buffer = b;
+ byteArray = QByteArray::fromRawData(buffer->buffer().constData() + buffer->pos(), buffer->size() - buffer->pos());
+ arrayImpl = new QNonContiguousByteDeviceByteArrayImpl(&byteArray);
+ arrayImpl->setParent(this);
+ connect(arrayImpl, SIGNAL(readyRead()), SIGNAL(readyRead()));
+ connect(arrayImpl, SIGNAL(readProgress(qint64,qint64)), SIGNAL(readProgress(qint64,qint64)));
+}
+
+QNonContiguousByteDeviceBufferImpl::~QNonContiguousByteDeviceBufferImpl()
+{
+}
+
+const char* QNonContiguousByteDeviceBufferImpl::readPointer(qint64 maximumLength, qint64 &len)
+{
+ return arrayImpl->readPointer(maximumLength, len);
+}
+
+bool QNonContiguousByteDeviceBufferImpl::advanceReadPointer(qint64 amount)
+{
+ return arrayImpl->advanceReadPointer(amount);
+}
+
+bool QNonContiguousByteDeviceBufferImpl::atEnd()
+{
+ return arrayImpl->atEnd();
+}
+
+bool QNonContiguousByteDeviceBufferImpl::reset()
+{
+ if (resetDisabled)
+ return false;
+ return arrayImpl->reset();
+}
+
+qint64 QNonContiguousByteDeviceBufferImpl::size()
+{
+ return arrayImpl->size();
+}
+
+QNonContiguousByteDeviceByteArrayImpl::QNonContiguousByteDeviceByteArrayImpl(QByteArray *ba) : QNonContiguousByteDevice(), currentPosition(0)
+{
+ byteArray = ba;
+}
+
+QNonContiguousByteDeviceByteArrayImpl::~QNonContiguousByteDeviceByteArrayImpl()
+{
+}
+
+const char* QNonContiguousByteDeviceByteArrayImpl::readPointer(qint64 maximumLength, qint64 &len)
+{
+ if (atEnd()) {
+ len = -1;
+ return 0;
+ }
+
+ if (maximumLength != -1)
+ len = qMin(maximumLength, size() - currentPosition);
+ else
+ len = size() - currentPosition;
+
+ return byteArray->constData() + currentPosition;
+}
+
+bool QNonContiguousByteDeviceByteArrayImpl::advanceReadPointer(qint64 amount)
+{
+ currentPosition += amount;
+ emit readProgress(currentPosition, size());
+ return true;
+}
+
+bool QNonContiguousByteDeviceByteArrayImpl::atEnd()
+{
+ return currentPosition >= size();
+}
+
+bool QNonContiguousByteDeviceByteArrayImpl::reset()
+{
+ if (resetDisabled)
+ return false;
+
+ currentPosition = 0;
+ return true;
+}
+
+qint64 QNonContiguousByteDeviceByteArrayImpl::size()
+{
+ return byteArray->size();
+}
+
+QNonContiguousByteDeviceRingBufferImpl::QNonContiguousByteDeviceRingBufferImpl(QRingBuffer *rb)
+ : QNonContiguousByteDevice(), currentPosition(0)
+{
+ ringBuffer = rb;
+}
+
+QNonContiguousByteDeviceRingBufferImpl::~QNonContiguousByteDeviceRingBufferImpl()
+{
+};
+
+const char* QNonContiguousByteDeviceRingBufferImpl::readPointer(qint64 maximumLength, qint64 &len)
+{
+ if (atEnd()) {
+ len = -1;
+ return 0;
+ }
+
+ const char *returnValue = ringBuffer->readPointerAtPosition(currentPosition, len);
+
+ if (maximumLength != -1)
+ len = qMin(len, maximumLength);
+
+ return returnValue;
+};
+
+bool QNonContiguousByteDeviceRingBufferImpl::advanceReadPointer(qint64 amount)
+{
+ currentPosition += amount;
+ emit readProgress(currentPosition, size());
+ return true;
+};
+
+bool QNonContiguousByteDeviceRingBufferImpl::atEnd()
+{
+ return currentPosition >= size();
+};
+
+bool QNonContiguousByteDeviceRingBufferImpl::reset()
+{
+ if (resetDisabled)
+ return false;
+
+ currentPosition = 0;
+ return true;
+};
+
+qint64 QNonContiguousByteDeviceRingBufferImpl::size()
+{
+ return ringBuffer->size();
+};
+
+QNonContiguousByteDeviceIoDeviceImpl::QNonContiguousByteDeviceIoDeviceImpl(QIODevice *d)
+ : QNonContiguousByteDevice(),
+ currentReadBuffer(0), currentReadBufferSize(16*1024),
+ currentReadBufferAmount(0), currentReadBufferPosition(0), totalAdvancements(0),
+ eof(false)
+{
+ device = d;
+ initialPosition = d->pos();
+ connect(device, SIGNAL(readyRead()), this, SIGNAL(readyRead()), Qt::QueuedConnection);
+ connect(device, SIGNAL(readChannelFinished()), this, SIGNAL(readyRead()), Qt::QueuedConnection);
+};
+
+QNonContiguousByteDeviceIoDeviceImpl::~QNonContiguousByteDeviceIoDeviceImpl()
+{
+ delete currentReadBuffer;
+};
+
+const char* QNonContiguousByteDeviceIoDeviceImpl::readPointer(qint64 maximumLength, qint64 &len)
+{
+ if (eof == true) {
+ len = -1;
+ return 0;
+ }
+
+ if (currentReadBuffer == 0)
+ currentReadBuffer = new QByteArray(currentReadBufferSize, '\0'); // lazy alloc
+
+ if (maximumLength == -1)
+ maximumLength = currentReadBufferSize;
+
+ if (currentReadBufferAmount - currentReadBufferPosition > 0) {
+ len = currentReadBufferAmount - currentReadBufferPosition;
+ return currentReadBuffer->data() + currentReadBufferPosition;
+ }
+
+ qint64 haveRead = device->read(currentReadBuffer->data(), qMin(maximumLength, currentReadBufferSize));
+
+ if ((haveRead == -1) || (haveRead == 0 && device->atEnd() && !device->isSequential())) {
+ eof = true;
+ len = -1;
+ // size was unknown before, emit a readProgress with the final size
+ if (size() == -1)
+ emit readProgress(totalAdvancements, totalAdvancements);
+ return 0;
+ }
+
+ currentReadBufferAmount = haveRead;
+ currentReadBufferPosition = 0;
+
+ len = haveRead;
+ return currentReadBuffer->data();
+};
+
+bool QNonContiguousByteDeviceIoDeviceImpl::advanceReadPointer(qint64 amount)
+{
+ totalAdvancements += amount;
+
+ // normal advancement
+ currentReadBufferPosition += amount;
+
+ // advancing over that what has actually been read before
+ if (currentReadBufferPosition > currentReadBufferAmount) {
+ qint64 i = currentReadBufferPosition - currentReadBufferAmount;
+ while (i > 0) {
+ if (device->getChar(0) == false) {
+ emit readProgress(totalAdvancements - i, size());
+ return false; // ### FIXME handle eof
+ }
+ i--;
+ }
+
+ currentReadBufferPosition = 0;
+ currentReadBufferAmount = 0;
+ }
+
+ if (size() == -1)
+ emit readProgress(totalAdvancements, totalAdvancements);
+ else
+ emit readProgress(totalAdvancements, size());
+
+ return true;
+};
+
+bool QNonContiguousByteDeviceIoDeviceImpl::atEnd()
+{
+ return eof == true;
+};
+
+bool QNonContiguousByteDeviceIoDeviceImpl::reset()
+{
+ if (resetDisabled)
+ return false;
+
+ if (device->seek(initialPosition)) {
+ eof = false; // assume eof is false, it will be true after a read has been attempted
+ return true;
+ }
+
+ return false;
+};
+
+qint64 QNonContiguousByteDeviceIoDeviceImpl::size()
+{
+ // note that this is different from the size() implementation of QIODevice!
+
+ if (device->isSequential())
+ return -1;
+
+ return device->size() - initialPosition;
+};
+
+QByteDeviceWrappingIoDevice::QByteDeviceWrappingIoDevice(QNonContiguousByteDevice *bd) : QIODevice((QObject*)0)
+{
+ byteDevice = bd;
+ connect(bd, SIGNAL(readyRead()), SIGNAL(readyRead()));
+
+ open(ReadOnly);
+}
+
+QByteDeviceWrappingIoDevice::~QByteDeviceWrappingIoDevice()
+{
+
+}
+
+bool QByteDeviceWrappingIoDevice::isSequential() const
+{
+ return (byteDevice->size() == -1);
+}
+
+bool QByteDeviceWrappingIoDevice::atEnd() const
+{
+ return byteDevice->atEnd();
+}
+
+bool QByteDeviceWrappingIoDevice::reset()
+{
+ return byteDevice->reset();
+}
+
+qint64 QByteDeviceWrappingIoDevice::size() const
+{
+ if (isSequential())
+ return 0;
+
+ return byteDevice->size();
+}
+
+
+qint64 QByteDeviceWrappingIoDevice::readData( char * data, qint64 maxSize)
+{
+ qint64 len;
+ const char *readPointer = byteDevice->readPointer(maxSize, len);
+ if (len == -1)
+ return -1;
+
+ memcpy(data, readPointer, len);
+ byteDevice->advanceReadPointer(len);
+ return len;
+}
+
+qint64 QByteDeviceWrappingIoDevice::writeData( const char* data, qint64 maxSize)
+{
+ return -1;
+}
+
+/*!
+ \class QNonContiguousByteDeviceFactory
+ \since 4.6
+
+ \inmodule QtCore
+
+ Creates a QNonContiguousByteDevice out of a QIODevice,
+ QByteArray etc.
+
+ \sa QNonContiguousByteDevice
+
+ \internal
+*/
+
+/*!
+ \fn static QNonContiguousByteDevice* QNonContiguousByteDeviceFactory::create(QIODevice *device);
+
+ Create a QNonContiguousByteDevice out of a QIODevice.
+ For QFile, QBuffer and all other QIoDevice, sequential or not.
+
+ \internal
+*/
+QNonContiguousByteDevice* QNonContiguousByteDeviceFactory::create(QIODevice *device)
+{
+ // shortcut if it is a QBuffer
+ if (QBuffer* buffer = qobject_cast<QBuffer*>(device)) {
+ return new QNonContiguousByteDeviceBufferImpl(buffer);
+ }
+
+ // ### FIXME special case if device is a QFile that supports map()
+ // then we can actually deal with the file without using read/peek
+
+ // generic QIODevice
+ return new QNonContiguousByteDeviceIoDeviceImpl(device); // FIXME
+};
+
+/*!
+ \fn static QNonContiguousByteDevice* QNonContiguousByteDeviceFactory::create(QRingBuffer *ringBuffer);
+
+ Create a QNonContiguousByteDevice out of a QRingBuffer.
+
+ \internal
+*/
+QNonContiguousByteDevice* QNonContiguousByteDeviceFactory::create(QRingBuffer *ringBuffer)
+{
+ return new QNonContiguousByteDeviceRingBufferImpl(ringBuffer);
+};
+
+/*!
+ \fn static QNonContiguousByteDevice* QNonContiguousByteDeviceFactory::create(QByteArray *byteArray);
+
+ Create a QNonContiguousByteDevice out of a QByteArray.
+
+ \internal
+*/
+QNonContiguousByteDevice* QNonContiguousByteDeviceFactory::create(QByteArray *byteArray)
+{
+ return new QNonContiguousByteDeviceByteArrayImpl(byteArray);
+};
+
+/*!
+ \fn static QIODevice* QNonContiguousByteDeviceFactory::wrap(QNonContiguousByteDevice* byteDevice);
+
+ Wrap the \a byteDevice (possibly again) into a QIODevice.
+
+ \internal
+*/
+QIODevice* QNonContiguousByteDeviceFactory::wrap(QNonContiguousByteDevice* byteDevice)
+{
+ // ### FIXME if it already has been based on QIoDevice, we could that one out again
+ // and save some calling
+
+ // needed for FTP backend
+
+ return new QByteDeviceWrappingIoDevice(byteDevice);
+}
+
+QT_END_NAMESPACE
+