/****************************************************************************
**
** Copyright (C) 1992-2004 Trolltech AS. All rights reserved.
**
** This file is part of the core module of the Qt Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
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**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
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** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
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** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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****************************************************************************/

#include "qdatastream.h"

#ifndef QT_NO_DATASTREAM
#include "qbuffer.h"
#include "qstring.h"
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>

/*!
    \class QDataStream
    \reentrant
    \brief The QDataStream class provides serialization of binary data
    to a QIODevice.

    \ingroup io
    \mainclass

    A data stream is a binary stream of encoded information which is
    100% independent of the host computer's operating system, CPU or
    byte order. For example, a data stream that is written by a PC
    under Windows can be read by a Sun SPARC running Solaris.

    You can also use a data stream to read/write \link #raw raw
    unencoded binary data\endlink. If you want a "parsing" input
    stream, see QTextStream.

    The QDataStream class implements the serialization of C++'s basic
    data types, like \c char, \c short, \c int, \c char*, etc.
    Serialization of more complex data is accomplished by breaking up
    the data into primitive units.

    A data stream cooperates closely with a QIODevice. A QIODevice
    represents an input/output medium one can read data from and write
    data to. The QFile class is an example of an IO device.

    Example (write binary data to a stream):
    \code
        QFile file("file.dat");
        file.open(QIODevice::WriteOnly);
        QDataStream stream(&file);   // we will serialize the data into the file
        stream << "the answer is";   // serialize a string
        stream << (Q_INT32)42;       // serialize an integer
    \endcode

    Example (read binary data from a stream):
    \code
        QFile file("file.dat");
        file.open(QIODevice::ReadOnly);
        QDataStream stream(&file);   // read the data serialized from the file
        QString str;
        Q_INT32 a;
        stream >> str >> a;          // extract "the answer is" and 42
    \endcode

    Each item written to the stream is written in a predefined binary
    format that varies depending on the item's type. Supported Qt
    types include QBrush, QColor, QDateTime, QFont, QPixmap, QString,
    QVariant and many others. For the complete list of all Qt types
    supporting data streaming see the \link datastreamformat.html
    Format of the QDataStream operators \endlink.

    For integers it is best to always cast to a Qt integer type for
    writing, and to read back into the same Qt integer type. This
    ensures that you get integers of the size you want and insulates
    you from compiler and platform differences.

    To take one example, a \c char* string is written as a 32-bit
    integer equal to the length of the string including the NUL byte
    ('\0'), followed by all the characters of the string including the
    NUL byte. When reading a \c char* string, 4 bytes are read to
    create the 32-bit length value, then that many characters for the
    \c char* string including the NUL are read.

    The initial IODevice is usually set in the constructor, but can be
    changed with setDevice(). If you've reached the end of the data
    (or if there is no IODevice set) atEnd() will return true.

    \target versioning
    \section1 Versioning

    QDataStream's binary format has evolved since Qt 1.0, and is
    likely to continue evolving to reflect changes done in Qt. When
    inputting or outputting complex types, it's very important to
    make sure that the same version of the stream (version()) is used
    for reading and writing. If you need both forward and backward
    compatibility, you can hardcode the version number in the
    application:

    \code
        stream.setVersion(QDataStream::Qt_4_0);
    \endcode

    If you are producing a new binary data format, such as a file
    format for documents created by your application, you could use a
    QDataStream to write the data in a portable format. Typically, you
    would write a brief header containing a magic string and a version
    number to give yourself room for future expansion. For example:

    \code
        QFile file("file.xxx");
        file.open(QIODevice::WriteOnly);
        QDataStream stream(&file);

        // Write a header with a "magic number" and a version
        stream << (Q_UINT32)0xA0B0C0D0;
        stream << (Q_INT32)123;
        stream.setVersion(QDataStream::Qt_4_0);

        // Write the data
        stream << lots_of_interesting_data;
    \endcode

    Then read it in with:

    \code
        QFile file("file.xxx");
        file.open(QIODevice::ReadOnly);
        QDataStream stream(&file);

        // Read and check the header
        Q_UINT32 magic;
        stream >> magic;
        if (magic != 0xA0B0C0D0)
            return XXX_BAD_FILE_FORMAT;

        // Read the version
        Q_INT32 version;
        stream >> version;
        if (version < 100)
            return XXX_BAD_FILE_TOO_OLD;
        if (version > 123)
            return XXX_BAD_FILE_TOO_NEW;

        if (version <= 110)
            stream.setVersion(QDataStream::Qt_3_2);
        else
            stream.setVersion(QDataStream::Qt_4_0);

        // Read the data
        stream >> lots_of_interesting_data;
        if (version >= 120)
            stream >> data_new_in_XXX_version_1_2;
        stream >> other_interesting_data;
    \endcode

    You can select which byte order to use when serializing data. The
    default setting is big endian (MSB first). Changing it to little
    endian breaks the portability (unless the reader also changes to
    little endian). We recommend keeping this setting unless you have
    special requirements.

    \target raw
    \section1 Reading and writing raw binary data

    You may wish to read/write your own raw binary data to/from the
    data stream directly. Data may be read from the stream into a
    preallocated char * using readRawData(). Similarly data can be
    written to the stream using writeRawData(). Note that any
    encoding/decoding of the data must be done by you.

    A similar pair of functions is readBytes() and writeBytes(). These
    differ from their \e raw counterparts as follows: readBytes()
    reads a Q_UINT32 which is taken to be the length of the data to be
    read, then that number of bytes is read into the preallocated
    char*; writeBytes() writes a Q_UINT32 containing the length of the
    data, followed by the data. Note that any encoding/decoding of
    the data (apart from the length Q_UINT32) must be done by you.

    \sa QTextStream QVariant
*/

/*!
    \enum QDataStream::ByteOrder

    The byte order used for reading/writing the data.

    \value BigEndian Most significant byte first (the default)
    \value LittleEndian Less significant byte first
*/


/*****************************************************************************
  QDataStream member functions
 *****************************************************************************/

#ifndef QT_NO_DEBUG
#undef  CHECK_STREAM_PRECOND
#define CHECK_STREAM_PRECOND(retVal) \
    if (!dev) { \
        qWarning("QDataStream: No device"); \
        return retVal; \
    }
#else
#define CHECK_STREAM_PRECOND(retVal)
#endif

enum {
    DefaultStreamVersion = 7
};

// ### 4.0: when streaming invalid QVariants, just the type should
// be written, no "data" after it

/*!
    Constructs a data stream that has no IO device.

    \sa setDevice()
*/

QDataStream::QDataStream()
{
    dev = 0;
    owndev = false;
    byteorder = BigEndian;
    ver = DefaultStreamVersion;
    noswap = QSysInfo::ByteOrder == QSysInfo::BigEndian;
    q_status = Ok;
}

/*!
    Constructs a data stream that uses the IO device \a d.

    \warning If you use QSocket or QSocketDevice as the IO device \a d
    for reading data, you must make sure that enough data is available
    on the socket for the operation to successfully proceed;
    QDataStream does not have any means to handle or recover from
    short-reads.

    \sa setDevice(), device()
*/

QDataStream::QDataStream(QIODevice *d)
{
    dev = d;                                // set device
    owndev = false;
    byteorder = BigEndian;                        // default byte order
    ver = DefaultStreamVersion;
    noswap = QSysInfo::ByteOrder == QSysInfo::BigEndian;
    q_status = Ok;
}

#ifdef QT_COMPAT
QDataStream::QDataStream(QByteArray *a, int mode)
{
    QBuffer *buf = new QBuffer(a);
    buf->open(QIODevice::OpenMode(mode));
    dev = buf;
    owndev = true;
    byteorder = BigEndian;
    ver = DefaultStreamVersion;
    noswap = QSysInfo::ByteOrder == QSysInfo::BigEndian;
    q_status = Ok;
}
#endif

/*!
    Constructs a data stream that operates on a byte array, \a a. The
    \a mode is a QIODevice::mode(), usually either \c QIODevice::ReadOnly or
    \c QIODevice::WriteOnly. Alternatively, you can use QDataStream(const QByteArray&) if you
    just want to read from a byte array.

    Since QByteArray is not a QIODevice subclass, internally a QBuffer
    is created to wrap the byte array.
*/

QDataStream::QDataStream(QByteArray *a, QIODevice::OpenMode flags)
{
    QBuffer *buf = new QBuffer(a);
    buf->open(flags);
    dev = buf;
    owndev = true;
    byteorder = BigEndian;
    ver = DefaultStreamVersion;
    noswap = QSysInfo::ByteOrder == QSysInfo::BigEndian;
    q_status = Ok;
}

/*!
    Constructs a read-only data stream that operates on byte array \a a.
    Use QDataStream(QByteArray*, int) if you want to write to a byte
    array.

    Since QByteArray is not a QIODevice subclass, internally a QBuffer
    is created to wrap the byte array.
*/
QDataStream::QDataStream(const QByteArray &a)
{
    QBuffer *buf = new QBuffer;
    buf->setData(a);
    buf->open(QIODevice::ReadOnly);
    dev = buf;
    owndev = true;
    byteorder = BigEndian;
    ver = DefaultStreamVersion;
    noswap = QSysInfo::ByteOrder == QSysInfo::BigEndian;
    q_status = Ok;
}

/*!
    Destroys the data stream.

    The destructor will not affect the current IO device, unless it is
    an internal IO device (e.g. a QBuffer) processing a QByteArray
    passed in the \e constructor, in which case the internal IO device
    is destroyed.
*/

QDataStream::~QDataStream()
{
    if (owndev)
        delete dev;
}


/*!
    \fn QIODevice *QDataStream::device() const

    Returns the IO device currently set.

    \sa setDevice(), unsetDevice()
*/

/*!
    void QDataStream::setDevice(QIODevice *d)

    Sets the IO device to \a d.

    \sa device(), unsetDevice()
*/

void QDataStream::setDevice(QIODevice *d)
{
    if (owndev) {
        delete dev;
        owndev = false;
    }
    dev = d;
}

/*!
    Unsets the IO device. This is the same as calling setDevice(0).

    \sa device(), setDevice()
*/

void QDataStream::unsetDevice()
{
    setDevice(0);
}


/*!
    \fn bool QDataStream::atEnd() const

    Returns true if the IO device has reached the end position (end of
    the stream or file) or if there is no IO device set; otherwise
    returns false.

    \sa QIODevice::atEnd()
*/

bool QDataStream::atEnd() const
{
    return dev ? dev->atEnd() : true;
}

/*
*/

QDataStream::Status QDataStream::status() const
{
    return q_status;
}

/*
*/
void QDataStream::resetStatus()
{
    q_status = Ok;
}

/*

*/
void QDataStream::setStatus(Status status)
{
    if (q_status == Ok)
        q_status = status;
}

/*!\fn bool QDataStream::eof() const

    Use atEnd() instead.
*/

/*!
    \fn int QDataStream::byteOrder() const

    Returns the current byte order setting -- either \c BigEndian or
    \c LittleEndian.

    \sa setByteOrder()
*/

/*!
    Sets the serialization byte order to \a bo.

    The \a bo parameter can be \c QDataStream::BigEndian or \c
    QDataStream::LittleEndian.

    The default setting is big endian. We recommend leaving this
    setting unless you have special requirements.

    \sa byteOrder()
*/

void QDataStream::setByteOrder(ByteOrder bo)
{
    byteorder = bo;
    if (QSysInfo::ByteOrder == QSysInfo::BigEndian)
        noswap = (byteorder == BigEndian);
    else
        noswap = (byteorder == LittleEndian);
}


/*!
    \fn bool QDataStream::isPrintableData() const

    In Qt 4, this function always returns false.

    \sa setPrintableData()
*/

/*!
    \fn void QDataStream::setPrintableData(bool enable)

    In Qt 3, this function enabled output in a human-readable
    format if \a enable was false.

    In Qt 4, QDataStream no longer provides a human-readable output.
    This function does nothing.
*/

/*!
    \enum QDataStream::Version

    This enum provides symbolic synonyms for the data serialization
    format version numbers.

    \value Qt_1_0 Version 1 (Qt 1.x)
    \value Qt_2_0 Version 2 (Qt 2.0)
    \value Qt_2_1 Version 3 (Qt 2.1, 2.2, 2.3)
    \value Qt_3_0 Version 4 (Qt 3.0)
    \value Qt_3_1 Version 5 (Qt 3.1, 3.2)
    \value Qt_3_3 Version 6 (Qt 3.3)
    \value Qt_4_0 Version 7 (Qt 4.0)

    \sa setVersion(), version()
*/

/*!
    \fn int QDataStream::version() const

    Returns the version number of the data serialization format.

    \sa setVersion(), Version
*/

/*!
    \fn void QDataStream::setVersion(int v)

    Sets the version number of the data serialization format to \a v.

    You don't \e have to set a version if you are using the current
    version of Qt, but for your own custom binary formats we recommend
    that you do; see \link #versioning Versioning\endlink in the
    Detailed Description.

    In order to accommodate new functionality, the datastream
    serialization format of some Qt classes has changed in some
    versions of Qt. If you want to read data that was created by an
    earlier version of Qt, or write data that can be read by a
    program that was compiled with an earlier version of Qt, use this
    function to modify the serialization format used by QDataStream.

    \table
    \header \i Qt Version       \i QDataStream Version
    \row \i Qt 4.0              \i 7
    \row \i Qt 3.3              \i 6
    \row \i Qt 3.1, 3.2         \i 5
    \row \i Qt 3.0              \i 4
    \row \i Qt 2.1, 2.2, 2.3    \i 3
    \row \i Qt 2.0              \i 2
    \row \i Qt 1.x              \i 1
    \endtable

    The \l Version enum provides symbolic constants for the different
    versions of Qt. For example:

    \code
        QDataStream out(file);
        out.setVersion(QDataStream::Qt_4_0);
    \endcode

    \sa version(), Version
*/

/*****************************************************************************
  QDataStream read functions
 *****************************************************************************/

/*!
    \fn QDataStream &QDataStream::operator>>(Q_UINT8 &i)
    \overload

    Reads an unsigned byte from the stream into \a i, and returns a
    reference to the stream.
*/

/*!
    Reads a signed byte from the stream into \a i, and returns a
    reference to the stream.
*/

QDataStream &QDataStream::operator>>(Q_INT8 &i)
{
    i = 0;
    CHECK_STREAM_PRECOND(*this)
    char c;
    if (!dev->getChar(&c))
        setStatus(ReadPastEnd);
    else
        i = Q_INT8(c);
    return *this;
}


/*!
    \fn QDataStream &QDataStream::operator>>(Q_UINT16 &i)
    \overload

    Reads an unsigned 16-bit integer from the stream into \a i, and
    returns a reference to the stream.
*/

/*!
    \overload

    Reads a signed 16-bit integer from the stream into \a i, and
    returns a reference to the stream.
*/

QDataStream &QDataStream::operator>>(Q_INT16 &i)
{
    i = 0;
    CHECK_STREAM_PRECOND(*this)
    if (noswap) {
        if (dev->read((char *)&i, 2) != 2) {
            i = 0;
            setStatus(ReadPastEnd);
        }
    } else {
        register uchar *p = (uchar *)(&i);
        char b[2];
        if (dev->read(b, 2) == 2) {
            *p++ = b[1];
            *p = b[0];
        } else {
            setStatus(ReadPastEnd);
        }
    }
    return *this;
}


/*!
    \fn QDataStream &QDataStream::operator>>(Q_UINT32 &i)
    \overload

    Reads an unsigned 32-bit integer from the stream into \a i, and
    returns a reference to the stream.
*/

/*!
    \overload

    Reads a signed 32-bit integer from the stream into \a i, and
    returns a reference to the stream.
*/

QDataStream &QDataStream::operator>>(Q_INT32 &i)
{
    i = 0;
    CHECK_STREAM_PRECOND(*this)
    if (noswap) {
        if (dev->read((char *)&i, 4) != 4) {
            i = 0;
            setStatus(ReadPastEnd);
        }
    } else {                                        // swap bytes
        uchar *p = (uchar *)(&i);
        char b[4];
        if (dev->read(b, 4) == 4) {
            *p++ = b[3];
            *p++ = b[2];
            *p++ = b[1];
            *p   = b[0];
        } else {
            setStatus(ReadPastEnd);
        }
    }
    return *this;
}

/*!
    \fn QDataStream &QDataStream::operator>>(Q_UINT64 &i)
    \overload

    Reads an unsigned 64-bit integer from the stream, into \a i, and
    returns a reference to the stream.
*/

/*!
    \overload

    Reads a signed 64-bit integer from the stream into \a i, and
    returns a reference to the stream.
*/

QDataStream &QDataStream::operator>>(Q_INT64 &i)
{
    i = Q_INT64(0);
    CHECK_STREAM_PRECOND(*this)
    if (version() < 6) {
        Q_UINT32 i1, i2;
        *this >> i2 >> i1;
        i = ((Q_UINT64)i1 << 32) + i2;
    } else if (noswap) {                        // no conversion needed
        if (dev->read((char *)&i, 8) != 8) {
            i = Q_LONGLONG(0);
            setStatus(ReadPastEnd);
        }
    } else {                                        // swap bytes
        uchar *p = (uchar *)(&i);
        char b[8];
        if (dev->read(b, 8) == 8) {
            *p++ = b[7];
            *p++ = b[6];
            *p++ = b[5];
            *p++ = b[4];
            *p++ = b[3];
            *p++ = b[2];
            *p++ = b[1];
            *p   = b[0];
        } else {
            setStatus(ReadPastEnd);
        }
    }
    return *this;
}

/*!
    \overload

    Reads a 32-bit floating point number from the stream into \a f,
    using the standard IEEE 754 format. Returns a reference to the
    stream.
*/

QDataStream &QDataStream::operator>>(float &f)
{
    f = 0.0f;
    CHECK_STREAM_PRECOND(*this)
    if (noswap) {
        if (dev->read((char *)&f, 4) != 4) {
            f = 0.0f;
            setStatus(ReadPastEnd);
        }
    } else {                                        // swap bytes
        uchar *p = (uchar *)(&f);
        char b[4];
        if (dev->read(b, 4) == 4) {
            *p++ = b[3];
            *p++ = b[2];
            *p++ = b[1];
            *p = b[0];
        } else {
            setStatus(ReadPastEnd);
        }
    }
    return *this;
}


/*!
    \overload

    Reads a 64-bit floating point number from the stream into \a f,
    using the standard IEEE 754 format. Returns a reference to the
    stream.
*/

QDataStream &QDataStream::operator>>(double &f)
{
    f = 0.0;
    CHECK_STREAM_PRECOND(*this)
    if (noswap) {
        if (dev->read((char *)&f, 8) != 8) {
            f = 0.0;
            setStatus(ReadPastEnd);
        }
    } else {                                        // swap bytes
        register uchar *p = (uchar *)(&f);
        char b[8];
        if (dev->read(b, 8) == 8) {
            *p++ = b[7];
            *p++ = b[6];
            *p++ = b[5];
            *p++ = b[4];
            *p++ = b[3];
            *p++ = b[2];
            *p++ = b[1];
            *p   = b[0];
        } else {
            setStatus(ReadPastEnd);
        }
    }
    return *this;
}


/*!
    \overload

    Reads the '\0'-terminated string \a s from the stream and returns
    a reference to the stream.

    Space for the string is allocated using \c new -- the caller must
    destroy it with delete[].
*/

QDataStream &QDataStream::operator>>(char *&s)
{
    uint len = 0;
    return readBytes(s, len);
}


/*!
    Reads the buffer \a s from the stream and returns a reference to
    the stream.

    The buffer \a s is allocated using \c new. Destroy it with the \c
    delete[] operator.

    The \a l parameter is set to the length of the buffer. If the
    string read is empty, \a l is set to 0 and \a s is set to
    a null pointer.

    The serialization format is a Q_UINT32 length specifier first,
    then \a l bytes of data.

    \sa readRawData(), writeBytes()
*/

QDataStream &QDataStream::readBytes(char *&s, uint &l)
{
    s = 0;
    l = 0;
    CHECK_STREAM_PRECOND(*this)

    Q_UINT32 len;
    *this >> len;
    if (len == 0)
        return *this;

    const Q_UINT32 Step = 1024 * 1024;
    Q_UINT32 allocated = 0;
    char *prevBuf = 0;
    char *curBuf = 0;

    do {
        int blockSize = qMin(Step, len - allocated);
        prevBuf = curBuf;
        curBuf = new char[allocated + blockSize + 1];
        if (prevBuf) {
            memcpy(curBuf, prevBuf, allocated);
            delete prevBuf;
        }
        if (dev->read(curBuf + allocated, blockSize) != blockSize) {
            delete curBuf;
            setStatus(ReadPastEnd);
            return *this;
        }
        allocated += blockSize;
    } while (allocated < len);

    s = curBuf;
    s[len] = '\0';
    l = (uint)len;
    return *this;
}

/*!
    Reads \a len bytes from the stream into \a s and returns a
    reference to the stream.

    The buffer \a s must be preallocated. The data is \e not encoded.

    \sa readBytes(), QIODevice::read(), writeRawData()
*/

int QDataStream::readRawData(char *s, int len)
{
    CHECK_STREAM_PRECOND(-1)
    return dev->read(s, len);
}


/*****************************************************************************
  QDataStream write functions
 *****************************************************************************/


/*!
    \fn QDataStream &QDataStream::operator<<(Q_UINT8 i)
    \overload

    Writes an unsigned byte, \a i, to the stream and returns a
    reference to the stream.
*/

/*!
    Writes a signed byte, \a i, to the stream and returns a reference
    to the stream.
*/

QDataStream &QDataStream::operator<<(Q_INT8 i)
{
    CHECK_STREAM_PRECOND(*this)
    dev->putChar(i);
    return *this;
}


/*!
    \fn QDataStream &QDataStream::operator<<(Q_UINT16 i)
    \overload

    Writes an unsigned 16-bit integer, \a i, to the stream and returns
    a reference to the stream.
*/

/*!
    \overload

    Writes a signed 16-bit integer, \a i, to the stream and returns a
    reference to the stream.
*/

QDataStream &QDataStream::operator<<(Q_INT16 i)
{
    CHECK_STREAM_PRECOND(*this)
    if (noswap) {
        dev->write((char *)&i, sizeof(Q_INT16));
    } else {                                        // swap bytes
        register uchar *p = (uchar *)(&i);
        char b[2];
        b[1] = *p++;
        b[0] = *p;
        dev->write(b, 2);
    }
    return *this;
}

/*!
    \overload

    Writes a signed 32-bit integer, \a i, to the stream and returns a
    reference to the stream.
*/

QDataStream &QDataStream::operator<<(Q_INT32 i)
{
    CHECK_STREAM_PRECOND(*this)
    if (noswap) {
        dev->write((char *)&i, sizeof(Q_INT32));
    } else {                                        // swap bytes
        register uchar *p = (uchar *)(&i);
        char b[4];
        b[3] = *p++;
        b[2] = *p++;
        b[1] = *p++;
        b[0] = *p;
        dev->write(b, 4);
    }
    return *this;
}

/*!
    \fn QDataStream &QDataStream::operator<<(Q_UINT64 i)
    \overload

    Writes an unsigned 64-bit integer, \a i, to the stream and returns a
    reference to the stream.
*/

/*!
    \overload

    Writes a signed 64-bit integer, \a i, to the stream and returns a
    reference to the stream.
*/

QDataStream &QDataStream::operator<<(Q_INT64 i)
{
    CHECK_STREAM_PRECOND(*this)
    if (version() < 6) {
        Q_UINT32 i1, i2;
        *this >> i2 >> i1;
        i = ((Q_UINT64)i1 << 32) + i2;
    } else if (noswap) {                        // no conversion needed
        dev->write((char *)&i, sizeof(Q_INT64));
    } else {                                        // swap bytes
        register uchar *p = (uchar *)(&i);
        char b[8];
        b[7] = *p++;
        b[6] = *p++;
        b[5] = *p++;
        b[4] = *p++;
        b[3] = *p++;
        b[2] = *p++;
        b[1] = *p++;
        b[0] = *p;
        dev->write(b, 8);
    }
    return *this;
}

/*!
    \fn QDataStream &QDataStream::operator<<(Q_UINT32 i)
    \overload

    Writes an unsigned integer, \a i, to the stream as a 32-bit
    unsigned integer (Q_UINT32). Returns a reference to the stream.
*/

/*!
    \overload

    Writes a 32-bit floating point number, \a f, to the stream using
    the standard IEEE 754 format. Returns a reference to the stream.
*/

QDataStream &QDataStream::operator<<(float f)
{
    CHECK_STREAM_PRECOND(*this)
    float g = f;                                // fixes float-on-stack problem
    if (noswap) {                                // no conversion needed
        dev->write((char *)&g, sizeof(float));
    } else {                                // swap bytes
        register uchar *p = (uchar *)(&g);
        char b[4];
        b[3] = *p++;
        b[2] = *p++;
        b[1] = *p++;
        b[0] = *p;
        dev->write(b, 4);
    }
    return *this;
}


/*!
    \overload

    Writes a 64-bit floating point number, \a f, to the stream using
    the standard IEEE 754 format. Returns a reference to the stream.
*/

QDataStream &QDataStream::operator<<(double f)
{
    CHECK_STREAM_PRECOND(*this)
    if (noswap) {
        dev->write((char *)&f, sizeof(double));
    } else {
        register uchar *p = (uchar *)(&f);
        char b[8];
        b[7] = *p++;
        b[6] = *p++;
        b[5] = *p++;
        b[4] = *p++;
        b[3] = *p++;
        b[2] = *p++;
        b[1] = *p++;
        b[0] = *p;
        dev->write(b, 8);
    }
    return *this;
}


/*!
    \overload

    Writes the '\0'-terminated string \a s to the stream and returns a
    reference to the stream.

    The string is serialized using writeBytes().
*/

QDataStream &QDataStream::operator<<(const char *s)
{
    if (!s) {
        *this << (Q_UINT32)0;
        return *this;
    }
    uint len = qstrlen(s) + 1;                        // also write null terminator
    *this << (Q_UINT32)len;                        // write length specifier
    writeRawData(s, len);
    return *this;
}


/*!
    Writes the length specifier \a len and the buffer \a s to the
    stream and returns a reference to the stream.

    The \a len is serialized as a Q_UINT32, followed by \a len bytes
    from \a s. Note that the data is \e not encoded.

    \sa writeRawData(), readBytes()
*/

QDataStream &QDataStream::writeBytes(const char *s, uint len)
{
    CHECK_STREAM_PRECOND(*this)
    *this << (Q_UINT32)len;                        // write length specifier
    if (len)
        writeRawData(s, len);
    return *this;
}


/*!
    Writes \a len bytes from \a s to the stream and returns a
    reference to the stream. The data is \e not encoded.

    \sa writeBytes(), QIODevice::write(), readRawData()
*/

int QDataStream::writeRawData(const char *s, int len)
{
    CHECK_STREAM_PRECOND(-1)
    return dev->write(s, len);
}

#ifdef QT_COMPAT
/*!
    \fn QDataStream &QDataStream::readRawBytes(char *str, uint len)

    Use readRawData() instead.
*/

/*!
    \fn QDataStream &QDataStream::writeRawBytes(const char *str, uint len)

    Use writeRawData() instead.
*/
#endif

#endif // QT_NO_DATASTREAM
