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Diffstat (limited to 'src/corelib/text/qbytedata_p.h')
| -rw-r--r-- | src/corelib/text/qbytedata_p.h | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/src/corelib/text/qbytedata_p.h b/src/corelib/text/qbytedata_p.h new file mode 100644 index 0000000000..b319d75811 --- /dev/null +++ b/src/corelib/text/qbytedata_p.h @@ -0,0 +1,245 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QBYTEDATA_P_H +#define QBYTEDATA_P_H + +// +// W A R N I N G +// ------------- +// +// This file is not part of the Qt API. It exists purely as an +// implementation detail. This header file may change from version to +// version without notice, or even be removed. +// +// We mean it. +// + +#include <QtCore/private/qglobal_p.h> +#include <qbytearray.h> + +QT_BEGIN_NAMESPACE + +// this class handles a list of QByteArrays. It is a variant of QRingBuffer +// that avoid malloc/realloc/memcpy. +class QByteDataBuffer +{ +private: + QList<QByteArray> buffers; + qint64 bufferCompleteSize; + qint64 firstPos; +public: + QByteDataBuffer() : bufferCompleteSize(0), firstPos(0) + { + } + + ~QByteDataBuffer() + { + clear(); + } + + static inline void popFront(QByteArray &ba, qint64 n) + { + ba = QByteArray(ba.constData() + n, ba.size() - n); + } + + inline void squeezeFirst() + { + if (!buffers.isEmpty() && firstPos > 0) { + popFront(buffers.first(), firstPos); + firstPos = 0; + } + } + + inline void append(const QByteDataBuffer& other) + { + if (other.isEmpty()) + return; + + buffers.append(other.buffers); + bufferCompleteSize += other.byteAmount(); + + if (other.firstPos > 0) + popFront(buffers[bufferCount() - other.bufferCount()], other.firstPos); + } + + + inline void append(const QByteArray& bd) + { + if (bd.isEmpty()) + return; + + buffers.append(bd); + bufferCompleteSize += bd.size(); + } + + inline void prepend(const QByteArray& bd) + { + if (bd.isEmpty()) + return; + + squeezeFirst(); + + buffers.prepend(bd); + bufferCompleteSize += bd.size(); + } + + // return the first QByteData. User of this function has to free() its .data! + // preferably use this function to read data. + inline QByteArray read() + { + squeezeFirst(); + bufferCompleteSize -= buffers.first().size(); + return buffers.takeFirst(); + } + + // return everything. User of this function has to free() its .data! + // avoid to use this, it might malloc and memcpy. + inline QByteArray readAll() + { + return read(byteAmount()); + } + + // return amount. User of this function has to free() its .data! + // avoid to use this, it might malloc and memcpy. + inline QByteArray read(qint64 amount) + { + amount = qMin(byteAmount(), amount); + QByteArray byteData; + byteData.resize(amount); + read(byteData.data(), byteData.size()); + return byteData; + } + + // return amount bytes. User of this function has to free() its .data! + // avoid to use this, it will memcpy. + qint64 read(char* dst, qint64 amount) + { + amount = qMin(amount, byteAmount()); + qint64 originalAmount = amount; + char *writeDst = dst; + + while (amount > 0) { + const QByteArray &first = buffers.first(); + qint64 firstSize = first.size() - firstPos; + if (amount >= firstSize) { + // take it completely + bufferCompleteSize -= firstSize; + amount -= firstSize; + memcpy(writeDst, first.constData() + firstPos, firstSize); + writeDst += firstSize; + firstPos = 0; + buffers.takeFirst(); + } else { + // take a part of it & it is the last one to take + bufferCompleteSize -= amount; + memcpy(writeDst, first.constData() + firstPos, amount); + firstPos += amount; + amount = 0; + } + } + + return originalAmount; + } + + inline char getChar() + { + char c; + read(&c, 1); + return c; + } + + inline void clear() + { + buffers.clear(); + bufferCompleteSize = 0; + firstPos = 0; + } + + // The byte count of all QByteArrays + inline qint64 byteAmount() const + { + return bufferCompleteSize; + } + + // the number of QByteArrays + inline int bufferCount() const + { + return buffers.length(); + } + + inline bool isEmpty() const + { + return byteAmount() == 0; + } + + inline qint64 sizeNextBlock() const + { + if(buffers.isEmpty()) + return 0; + else + return buffers.first().size() - firstPos; + } + + inline QByteArray& operator[](int i) + { + if (i == 0) + squeezeFirst(); + + return buffers[i]; + } + + inline bool canReadLine() const { + int i = 0; + if (i < buffers.length()) { + if (buffers.at(i).indexOf('\n', firstPos) != -1) + return true; + ++i; + + for (; i < buffers.length(); i++) + if (buffers.at(i).contains('\n')) + return true; + } + return false; + } +}; + +QT_END_NAMESPACE + +#endif // QBYTEDATA_P_H |