UidCalculator Class Reference

#include <uid.h>

Static Public Member Functions
static uint64_t	getNewObjectId ()
static uint32_t	getNewInstanceId ()

Static Private Member Functions
static uint64_t	getCurrentMiroseconds ()

Detailed Description

Definition at line 27 of file uid.h.

Member Function Documentation

getCurrentMiroseconds()

uint64_t UidCalculator::getCurrentMiroseconds ( )

staticprivate

Definition at line 69 of file uid.cpp.

Referenced by getNewObjectId().

{
#if (defined _WIN32_) || (defined _MSC_VER)
    LARGE_INTEGER tickPerSecond;
    LARGE_INTEGER tick; // a point in time

    // get the high resolution counter's accuracy
    QueryPerformanceFrequency(&tickPerSecond);

    // what time is it ?
    QueryPerformanceCounter(&tick);

    // and here we get the current microsecond! \o/
    return (tick.QuadPart % tickPerSecond.QuadPart);
#else
    struct timeval tv;
    gettimeofday(&tv, 0);
    return tv.tv_usec;
#endif
}

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getNewInstanceId()

uint32_t UidCalculator::getNewInstanceId ( )

static

Get a new instance unique Id. It is made of from LSB to MSB:

• 2 byte process id
• 2 byte hashed host name

Definition at line 50 of file uid.cpp.

References i.

{
    uint32_t uid = (QCoreApplication::applicationPid() % (1<<16));

    QString hostname = QHostInfo::localHostName();
    QByteArray hashKey = QCryptographicHash::hash(hostname.toUtf8(), QCryptographicHash::Sha1);
    uint32_t hashHost = 0;

    for (int i = 0; i < hashKey.size(); i++) {
        char c = hashKey.at(i);
        hashHost += (uint32_t) c;
    }

    hashHost %= (1<<16);
    uid += (hashHost<<16);

    return uid;
}

getNewObjectId()

uint64_t UidCalculator::getNewObjectId ( )

static

Get a new object unique Id. It is the addition of:

• 6 digit microseconds in current second
• 4 byte Unix epoch multiplied by 1000000

Definition at line 35 of file uid.cpp.

References getCurrentMiroseconds().

{
    QDateTime currentDateTime = QDateTime::currentDateTime();
    uint64_t uid = currentDateTime.toTime_t();
    uid *= 1000000UL; // make room for microseconds

// Fallback to milliseconds:
//    QTime timeNow = QTime::currentTime();
//    uint64_t usecs = timeNow.msec() * 1000UL;
//    uid += usecs;
    uid += getCurrentMiroseconds();

    return uid;
}

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The documentation for this class was generated from the following files:

• sdrbase/util/uid.h
• sdrbase/util/uid.cpp