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/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying
** this package.
**
** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "quuid.h"
#include "qdatastream.h"
#include "qendian.h"
QT_BEGIN_NAMESPACE
#ifndef QT_NO_QUUID_STRING
template <class Char, class Integral>
void _q_toHex(Char *&dst, Integral value)
{
static const char digits[] = "0123456789abcdef";
if (sizeof(Integral) > 1)
value = qToBigEndian(value);
const char* p = reinterpret_cast<const char*>(&value);
for (uint i = 0; i < sizeof(Integral); ++i, dst += 2) {
uint j = (p[i] >> 4) & 0xf;
dst[0] = Char(digits[j]);
j = p[i] & 0xf;
dst[1] = Char(digits[j]);
}
}
template <class Char, class Integral>
bool _q_fromHex(const Char *&src, Integral &value)
{
value = 0;
for (uint i = 0; i < sizeof(Integral) * 2; ++i) {
int ch = *src++;
int tmp;
if (ch >= '0' && ch <= '9')
tmp = ch - '0';
else if (ch >= 'a' && ch <= 'f')
tmp = ch - 'a' + 10;
else if (ch >= 'A' && ch <= 'F')
tmp = ch - 'A' + 10;
else
return false;
value = value * 16 + tmp;
}
return true;
}
template <class Char>
void _q_uuidToHex(Char *&dst, const uint &d1, const ushort &d2, const ushort &d3, const uchar (&d4)[8])
{
*dst++ = Char('{');
_q_toHex(dst, d1);
*dst++ = Char('-');
_q_toHex(dst, d2);
*dst++ = Char('-');
_q_toHex(dst, d3);
*dst++ = Char('-');
for (int i = 0; i < 2; i++)
_q_toHex(dst, d4[i]);
*dst++ = Char('-');
for (int i = 2; i < 8; i++)
_q_toHex(dst, d4[i]);
*dst = Char('}');
}
template <class Char>
bool _q_uuidFromHex(const Char *&src, uint &d1, ushort &d2, ushort &d3, uchar (&d4)[8])
{
if (*src == Char('{'))
src++;
if (!_q_fromHex(src, d1)
|| *src++ != Char('-')
|| !_q_fromHex(src, d2)
|| *src++ != Char('-')
|| !_q_fromHex(src, d3)
|| *src++ != Char('-')
|| !_q_fromHex(src, d4[0])
|| !_q_fromHex(src, d4[1])
|| *src++ != Char('-')
|| !_q_fromHex(src, d4[2])
|| !_q_fromHex(src, d4[3])
|| !_q_fromHex(src, d4[4])
|| !_q_fromHex(src, d4[5])
|| !_q_fromHex(src, d4[6])
|| !_q_fromHex(src, d4[7])) {
return false;
}
return true;
}
#endif
/*!
\class QUuid
\brief The QUuid class stores a Universally Unique Identifier (UUID).
\reentrant
Using \e{U}niversally \e{U}nique \e{ID}entifiers (UUID) is a
standard way to uniquely identify entities in a distributed
computing environment. A UUID is a 16-byte (128-bit) number
generated by some algorithm that is meant to guarantee that the
UUID will be unique in the distributed computing environment where
it is used. The acronym GUID is often used instead, \e{G}lobally
\e{U}nique \e{ID}entifiers, but it refers to the same thing.
\target Variant field
Actually, the GUID is one \e{variant} of UUID. Multiple variants
are in use. Each UUID contains a bit field that specifies which
type (variant) of UUID it is. Call variant() to discover which
type of UUID an instance of QUuid contains. It extracts the three
most signifcant bits of byte 8 of the 16 bytes. In QUuid, byte 8
is \c{QUuid::data4[0]}. If you create instances of QUuid using the
constructor that accepts all the numeric values as parameters, use
the following table to set the three most significant bits of
parameter \c{b1}, which becomes \c{QUuid::data4[0]} and contains
the variant field in its three most significant bits. In the
table, 'x' means \e {don't care}.
\table
\header
\o msb0
\o msb1
\o msb2
\o Variant
\row
\o 0
\o x
\o x
\o NCS (Network Computing System)
\row
\o 1
\o 0
\o x
\o DCE (Distributed Computing Environment)
\row
\o 1
\o 1
\o 0
\o Microsoft (GUID)
\row
\o 1
\o 1
\o 1
\o Reserved for future expansion
\endtable
\target Version field
If variant() returns QUuid::DCE, the UUID also contains a
\e{version} field in the four most significant bits of
\c{QUuid::data3}, and you can call version() to discover which
version your QUuid contains. If you create instances of QUuid
using the constructor that accepts all the numeric values as
parameters, use the following table to set the four most
significant bits of parameter \c{w2}, which becomes
\c{QUuid::data3} and contains the version field in its four most
significant bits.
\table
\header
\o msb0
\o msb1
\o msb2
\o msb3
\o Version
\row
\o 0
\o 0
\o 0
\o 1
\o Time
\row
\o 0
\o 0
\o 1
\o 0
\o Embedded POSIX
\row
\o 0
\o 0
\o 1
\o 1
\o Name
\row
\o 0
\o 1
\o 0
\o 0
\o Random
\endtable
The field layouts for the DCE versions listed in the table above
are specified in the \l{http://www.ietf.org/rfc/rfc4122.txt}
{Network Working Group UUID Specification}.
Most platforms provide a tool for generating new UUIDs, e.g. \c
uuidgen and \c guidgen. You can also use createUuid(). UUIDs
generated by createUuid() are of the random type. Their
QUuid::Version bits are set to QUuid::Random, and their
QUuid::Variant bits are set to QUuid::DCE. The rest of the UUID is
composed of random numbers. Theoretically, this means there is a
small chance that a UUID generated by createUuid() will not be
unique. But it is
\l{http://en.wikipedia.org/wiki/Universally_Unique_Identifier#Random_UUID_probability_of_duplicates}
{a \e{very} small chance}.
UUIDs can be constructed from numeric values or from strings, or
using the static createUuid() function. They can be converted to a
string with toString(). UUIDs have a variant() and a version(),
and null UUIDs return true from isNull().
*/
/*!
\fn QUuid::QUuid(const GUID &guid)
Casts a Windows \a guid to a Qt QUuid.
\warning This function is only for Windows platforms.
*/
/*!
\fn QUuid &QUuid::operator=(const GUID &guid)
Assigns a Windows \a guid to a Qt QUuid.
\warning This function is only for Windows platforms.
*/
/*!
\fn QUuid::operator GUID() const
Returns a Windows GUID from a QUuid.
\warning This function is only for Windows platforms.
*/
/*!
\fn QUuid::QUuid()
Creates the null UUID. toString() will output the null UUID
as "{00000000-0000-0000-0000-000000000000}".
*/
/*!
\fn QUuid::QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3, uchar b4, uchar b5, uchar b6, uchar b7, uchar b8)
Creates a UUID with the value specified by the parameters, \a l,
\a w1, \a w2, \a b1, \a b2, \a b3, \a b4, \a b5, \a b6, \a b7, \a
b8.
Example:
\snippet doc/src/snippets/code/src_corelib_plugin_quuid.cpp 0
*/
#ifndef QT_NO_QUUID_STRING
/*!
Creates a QUuid object from the string \a text, which must be
formatted as five hex fields separated by '-', e.g.,
"{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where 'x' is a hex
digit. The curly braces shown here are optional, but it is normal to
include them. If the conversion fails, a null UUID is created. See
toString() for an explanation of how the five hex fields map to the
public data members in QUuid.
\sa toString(), QUuid()
*/
QUuid::QUuid(const QString &text)
{
if (text.length() < 36) {
*this = QUuid();
return;
}
const ushort *data = reinterpret_cast<const ushort *>(text.unicode());
if (*data == '{' && text.length() < 37) {
*this = QUuid();
return;
}
if (!_q_uuidFromHex(data, data1, data2, data3, data4)) {
*this = QUuid();
return;
}
}
/*!
\internal
*/
QUuid::QUuid(const char *text)
{
*this = QUuid(QString::fromLatin1(text));
}
#endif
/*!
\fn bool QUuid::operator==(const QUuid &other) const
Returns true if this QUuid and the \a other QUuid are identical;
otherwise returns false.
*/
/*!
\fn bool QUuid::operator!=(const QUuid &other) const
Returns true if this QUuid and the \a other QUuid are different;
otherwise returns false.
*/
#ifndef QT_NO_QUUID_STRING
/*!
\fn QUuid::operator QString() const
Returns the string representation of the uuid.
\sa toString()
*/
/*!
Returns the string representation of this QUuid. The string is
formatted as five hex fields separated by '-' and enclosed in
curly braces, i.e., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where
'x' is a hex digit. From left to right, the five hex fields are
obtained from the four public data members in QUuid as follows:
\table
\header
\o Field #
\o Source
\row
\o 1
\o data1
\row
\o 2
\o data2
\row
\o 3
\o data3
\row
\o 4
\o data4[0] .. data4[1]
\row
\o 5
\o data4[2] .. data4[7]
\endtable
*/
QString QUuid::toString() const
{
QString result(38, Qt::Uninitialized);
ushort *data = (ushort *)result.unicode();
_q_uuidToHex(data, data1, data2, data3, data4);
return result;
}
#endif
#ifndef QT_NO_DATASTREAM
/*!
\relates QUuid
Writes the UUID \a id to the data stream \a s.
*/
QDataStream &operator<<(QDataStream &s, const QUuid &id)
{
s << (quint32)id.data1;
s << (quint16)id.data2;
s << (quint16)id.data3;
for (int i = 0; i < 8; i++)
s << (quint8)id.data4[i];
return s;
}
/*!
\relates QUuid
Reads a UUID from the stream \a s into \a id.
*/
QDataStream &operator>>(QDataStream &s, QUuid &id)
{
quint32 u32;
quint16 u16;
quint8 u8;
s >> u32;
id.data1 = u32;
s >> u16;
id.data2 = u16;
s >> u16;
id.data3 = u16;
for (int i = 0; i < 8; i++) {
s >> u8;
id.data4[i] = u8;
}
return s;
}
#endif // QT_NO_DATASTREAM
/*!
Returns true if this is the null UUID
{00000000-0000-0000-0000-000000000000}; otherwise returns false.
*/
bool QUuid::isNull() const
{
return data4[0] == 0 && data4[1] == 0 && data4[2] == 0 && data4[3] == 0 &&
data4[4] == 0 && data4[5] == 0 && data4[6] == 0 && data4[7] == 0 &&
data1 == 0 && data2 == 0 && data3 == 0;
}
/*!
\enum QUuid::Variant
This enum defines the values used in the \l{Variant field}
{variant field} of the UUID. The value in the variant field
determines the layout of the 128-bit value.
\value VarUnknown Variant is unknown
\value NCS Reserved for NCS (Network Computing System) backward compatibility
\value DCE Distributed Computing Environment, the scheme used by QUuid
\value Microsoft Reserved for Microsoft backward compatibility (GUID)
\value Reserved Reserved for future definition
*/
/*!
\enum QUuid::Version
This enum defines the values used in the \l{Version field}
{version field} of the UUID. The version field is meaningful
only if the value in the \l{Variant field} {variant field}
is QUuid::DCE.
\value VerUnknown Version is unknown
\value Time Time-based, by using timestamp, clock sequence, and
MAC network card address (if available) for the node sections
\value EmbeddedPOSIX DCE Security version, with embedded POSIX UUIDs
\value Name Name-based, by using values from a name for all sections
\value Random Random-based, by using random numbers for all sections
*/
/*!
\fn QUuid::Variant QUuid::variant() const
Returns the value in the \l{Variant field} {variant field} of the
UUID. If the return value is QUuid::DCE, call version() to see
which layout it uses. The null UUID is considered to be of an
unknown variant.
\sa version()
*/
QUuid::Variant QUuid::variant() const
{
if (isNull())
return VarUnknown;
// Check the 3 MSB of data4[0]
if ((data4[0] & 0x80) == 0x00) return NCS;
else if ((data4[0] & 0xC0) == 0x80) return DCE;
else if ((data4[0] & 0xE0) == 0xC0) return Microsoft;
else if ((data4[0] & 0xE0) == 0xE0) return Reserved;
return VarUnknown;
}
/*!
\fn QUuid::Version QUuid::version() const
Returns the \l{Version field} {version field} of the UUID, if the
UUID's \l{Variant field} {variant field} is QUuid::DCE. Otherwise
it returns QUuid::VerUnknown.
\sa variant()
*/
QUuid::Version QUuid::version() const
{
// Check the 4 MSB of data3
Version ver = (Version)(data3>>12);
if (isNull()
|| (variant() != DCE)
|| ver < Time
|| ver > Random)
return VerUnknown;
return ver;
}
/*!
\fn bool QUuid::operator<(const QUuid &other) const
Returns true if this QUuid has the same \l{Variant field}
{variant field} as the \a other QUuid and is lexicographically
\e{before} the \a other QUuid. If the \a other QUuid has a
different variant field, the return value is determined by
comparing the two \l{QUuid::Variant} {variants}.
\sa variant()
*/
#define ISLESS(f1, f2) if (f1!=f2) return (f1<f2);
bool QUuid::operator<(const QUuid &other) const
{
if (variant() != other.variant())
return variant() < other.variant();
ISLESS(data1, other.data1);
ISLESS(data2, other.data2);
ISLESS(data3, other.data3);
for (int n = 0; n < 8; n++) {
ISLESS(data4[n], other.data4[n]);
}
return false;
}
/*!
\fn bool QUuid::operator>(const QUuid &other) const
Returns true if this QUuid has the same \l{Variant field}
{variant field} as the \a other QUuid and is lexicographically
\e{after} the \a other QUuid. If the \a other QUuid has a
different variant field, the return value is determined by
comparing the two \l{QUuid::Variant} {variants}.
\sa variant()
*/
#define ISMORE(f1, f2) if (f1!=f2) return (f1>f2);
bool QUuid::operator>(const QUuid &other) const
{
if (variant() != other.variant())
return variant() > other.variant();
ISMORE(data1, other.data1);
ISMORE(data2, other.data2);
ISMORE(data3, other.data3);
for (int n = 0; n < 8; n++) {
ISMORE(data4[n], other.data4[n]);
}
return false;
}
/*!
\fn QUuid QUuid::createUuid()
On any platform other than Windows, this function returns a new
UUID with variant QUuid::DCE and version QUuid::Random. If
the /dev/urandom device exists, then the numbers used to construct
the UUID will be of cryptographic quality, which will make the UUID
unique. Otherwise, the numbers of the UUID will be obtained from
the local pseudo-random number generator (qrand(), which is seeded
by qsrand()) which is usually not of cryptograhic quality, which
means that the UUID can't be guaranteed to be unique.
On a Windows platform, a GUID is generated, which almost certainly
\e{will} be unique, on this or any other system, networked or not.
\sa variant(), version()
*/
#if defined(Q_OS_WIN32) && ! defined(Q_CC_MWERKS)
QT_BEGIN_INCLUDE_NAMESPACE
#include <objbase.h> // For CoCreateGuid
QT_END_INCLUDE_NAMESPACE
QUuid QUuid::createUuid()
{
GUID guid;
CoCreateGuid(&guid);
QUuid result = guid;
return result;
}
#else // !Q_OS_WIN32
QT_BEGIN_INCLUDE_NAMESPACE
#include "qdatetime.h"
#include "qfile.h"
#include "qthreadstorage.h"
#include <stdlib.h> // for RAND_MAX
QT_END_INCLUDE_NAMESPACE
#if !defined(QT_BOOTSTRAPPED) && defined(Q_OS_UNIX)
Q_GLOBAL_STATIC(QThreadStorage<QFile *>, devUrandomStorage);
#endif
QUuid QUuid::createUuid()
{
QUuid result;
uint *data = &(result.data1);
#if defined(Q_OS_UNIX)
QFile *devUrandom;
# if !defined(QT_BOOTSTRAPPED)
devUrandom = devUrandomStorage()->localData();
if (!devUrandom) {
devUrandom = new QFile(QLatin1String("/dev/urandom"));
devUrandom->open(QIODevice::ReadOnly | QIODevice::Unbuffered);
devUrandomStorage()->setLocalData(devUrandom);
}
# else
QFile file(QLatin1String("/dev/urandom"));
devUrandom = &file;
devUrandom->open(QIODevice::ReadOnly | QIODevice::Unbuffered);
# endif
enum { AmountToRead = 4 * sizeof(uint) };
if (devUrandom->isOpen()
&& devUrandom->read((char *) data, AmountToRead) == AmountToRead) {
// we got what we wanted, nothing more to do
;
} else
#endif
{
static const int intbits = sizeof(int)*8;
static int randbits = 0;
if (!randbits) {
int r = 0;
int max = RAND_MAX;
do { ++r; } while ((max=max>>1));
randbits = r;
}
// Seed the PRNG once per thread with a combination of current time, a
// stack address and a serial counter (since thread stack addresses are
// re-used).
#ifndef QT_BOOTSTRAPPED
static QThreadStorage<int *> uuidseed;
if (!uuidseed.hasLocalData())
{
int *pseed = new int;
static QBasicAtomicInt serial = Q_BASIC_ATOMIC_INITIALIZER(2);
qsrand(*pseed = QDateTime::currentDateTime().toTime_t()
+ quintptr(&pseed)
+ serial.fetchAndAddRelaxed(1));
uuidseed.setLocalData(pseed);
}
#else
static bool seeded = false;
if (!seeded)
qsrand(QDateTime::currentDateTime().toTime_t()
+ quintptr(&seeded));
#endif
int chunks = 16 / sizeof(uint);
while (chunks--) {
uint randNumber = 0;
for (int filled = 0; filled < intbits; filled += randbits)
randNumber |= qrand()<<filled;
*(data+chunks) = randNumber;
}
}
result.data4[0] = (result.data4[0] & 0x3F) | 0x80; // UV_DCE
result.data3 = (result.data3 & 0x0FFF) | 0x4000; // UV_Random
return result;
}
#endif // !Q_OS_WIN32
/*!
\fn bool QUuid::operator==(const GUID &guid) const
Returns true if this UUID is equal to the Windows GUID \a guid;
otherwise returns false.
*/
/*!
\fn bool QUuid::operator!=(const GUID &guid) const
Returns true if this UUID is not equal to the Windows GUID \a
guid; otherwise returns false.
*/
QT_END_NAMESPACE
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