/**************************************************************************** ** ** Copyright (C) 2010 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. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial Usage ** Licensees holding valid Qt Commercial licenses may use this file in ** accordance with the Qt Commercial License Agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and Nokia. ** ** 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. ** ** 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 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" QT_BEGIN_NAMESPACE /*! \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) { bool ok; if (text.isEmpty()) { *this = QUuid(); return; } QString temp = text.toUpper(); if (temp[0] != QLatin1Char('{')) temp = QLatin1Char('{') + text; if (text[(int)text.length()-1] != QLatin1Char('}')) temp += QLatin1Char('}'); data1 = temp.mid(1, 8).toULongLong(&ok, 16); if (!ok) { *this = QUuid(); return; } data2 = temp.mid(10, 4).toUInt(&ok, 16); if (!ok) { *this = QUuid(); return; } data3 = temp.mid(15, 4).toUInt(&ok, 16); if (!ok) { *this = QUuid(); return; } data4[0] = temp.mid(20, 2).toUInt(&ok, 16); if (!ok) { *this = QUuid(); return; } data4[1] = temp.mid(22, 2).toUInt(&ok, 16); if (!ok) { *this = QUuid(); return; } for (int i = 2; i<8; i++) { data4[i] = temp.mid(25 + (i-2)*2, 2).toUShort(&ok, 16); if (!ok) { *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() */ static QString uuidhex(uint data, int digits) { return QString::number(data, 16).rightJustified(digits, QLatin1Char('0')); } /*! 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; QChar dash = QLatin1Char('-'); result = QLatin1Char('{') + uuidhex(data1,8); result += dash; result += uuidhex(data2,4); result += dash; result += uuidhex(data3,4); result += dash; result += uuidhex(data4[0],2); result += uuidhex(data4[1],2); result += dash; for (int i = 2; i < 8; i++) result += uuidhex(data4[i],2); return result + QLatin1Char('}'); } #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(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. The random numbers used to construct the UUID are obtained from the local pseudo-random generator, qrand(), which is usually not a cryptographic quality random number generator. Therefore, a UUID generated by this function can't be guaranteed to be unique. If the pseudo-random number generator for the calling thread has not yet been seeded, this function will seed the pseudo-random number generator by calling qsrand(). 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 // 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 "stdlib.h" // For srand/rand QT_END_INCLUDE_NAMESPACE extern void qsrand(); // in qglobal.cpp QUuid QUuid::createUuid() { static const int intbits = sizeof(int)*8; static int randbits = 0; if (!randbits) { int max = RAND_MAX; do { ++randbits; } while ((max=max>>1)); } // reseed, but only if not already seeded qsrand(); QUuid result; uint *data = &(result.data1); int chunks = 16 / sizeof(uint); while (chunks--) { uint randNumber = 0; for (int filled = 0; filled < intbits; filled += randbits) randNumber |= qrand()<