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timersmanager 解析

最近在看crtmp源代码,看到timersmanager 模块时感觉很难理解,花了不少时间反复思考该模块

的逻辑,现在思考的结果记录下来,方便以后查阅。

构造函数中将处理时间方法传进来,将_lastTime赋值为当前时间,将当前slot Index设置为0,Slot指针

赋为空,slot数目赋为0。slot可以理解为槽。

TimersManager::TimersManager(ProcessTimerEvent processTimerEvent) {	_processTimerEvent = processTimerEvent;	_lastTime = time(NULL);	_currentSlotIndex = 0;	_pSlots = NULL;	_slotsCount = 0;}

  析构时释放掉slot,无需多解释。

TimersManager::~TimersManager() {    if (_pSlots != NULL)        delete[] _pSlots;}

移除处理事件方法,将id为eventTimerId的事件处理方法从所有的slot中移除掉

void TimersManager::RemoveTimer(uint32_t eventTimerId) {    for (uint32_t i = 0; i < _slotsCount; i++) {        if (MAP_HAS1(_pSlots[i].timers, eventTimerId)) {            _pSlots[i].timers.erase(eventTimerId);        }    }}

 

void TimersManager::AddTimer(TimerEvent& timerEvent) {    UpdatePeriods(timerEvent.period);    uint32_t min = 999999999;    uint32_t startIndex = 0;    for (uint32_t i = 0; i < _slotsCount; i++) {        if (min > _pSlots[i].timers.size()) {            startIndex = i;            min = _pSlots[i].timers.size();        }    }    while (!MAP_HAS1(_pSlots[startIndex % _slotsCount].timers, timerEvent.id)) {        _pSlots[startIndex % _slotsCount].timers[timerEvent.id] = timerEvent;        startIndex += timerEvent.period;    }}void TimersManager::TimeElapsed(uint64_t currentTime) {    int64_t delta = currentTime - _lastTime;    _lastTime = currentTime;    if (delta <= 0 || _slotsCount == 0)        return;    for (int32_t i = 0; i < delta; i++) {        FOR_MAP(_pSlots[_currentSlotIndex % _slotsCount].timers, uint32_t, TimerEvent, j) {            _processTimerEvent(MAP_VAL(j));        }        _currentSlotIndex++;    }}void TimersManager::UpdatePeriods(uint32_t period) {    if (MAP_HAS1(_periodsMap, period))        return;    _periodsMap[period] = period;    ADD_VECTOR_END(_periodsVector, period);    uint32_t newSlotsCount = LCM(_periodsVector, 0);    if (newSlotsCount == 0)        newSlotsCount = period;    if (newSlotsCount == _slotsCount)        return;    Slot *pNewSlots = new Slot[newSlotsCount];    if (_slotsCount > 0) {        for (uint32_t i = 0; i < newSlotsCount; i++) {            pNewSlots[i] = _pSlots[i % _slotsCount];        }        delete[] _pSlots;    }    _pSlots = pNewSlots;    _slotsCount = newSlotsCount;}uint32_t TimersManager::GCD(uint32_t a, uint32_t b) {    while (b != 0) {        uint32_t t = b;        b = a % b;        a = t;    }    return a;}uint32_t TimersManager::LCM(uint32_t a, uint32_t b) {    if (a == 0 || b == 0)        return 0;    uint32_t result = a * b / GCD(a, b);    FINEST("a: %u; b: %u; r: %u", a, b, result);    return result;}uint32_t TimersManager::GCD(vector<uint32_t> numbers, uint32_t startIndex) {    if (numbers.size() <= 1)        return 0;    if (numbers.size() <= startIndex)        return 0;    if (numbers.size() - startIndex > 2) {        return GCD(numbers[startIndex], GCD(numbers, startIndex + 1));    } else {        return GCD(numbers[startIndex], numbers[startIndex + 1]);    }}uint32_t TimersManager::LCM(vector<uint32_t> numbers, uint32_t startIndex) {    if (numbers.size() <= 1)        return 0;    if (numbers.size() <= startIndex)        return 0;    if (numbers.size() - startIndex > 2) {        return LCM(numbers[startIndex], LCM(numbers, startIndex + 1));    } else {        return LCM(numbers[startIndex], numbers[startIndex + 1]);    }}/* * * TimersManager tm(NULL);    TimerEvent t1 = {2, 1, NULL};    TimerEvent t2 = {3, 2, NULL};    TimerEvent t3 = {3, 3, NULL};    TimerEvent t4 = {4, 4, NULL};    TimerEvent t5 = {3, 5, NULL};    TimerEvent t6 = {2, 6, NULL};    TimerEvent t7 = {4, 7, NULL};    tm.AddTimer(t1);    tm.AddTimer(t2);    tm.AddTimer(t3);    tm.AddTimer(t4);    tm.AddTimer(t5);    tm.AddTimer(t6);    tm.AddTimer(t7); * * */

 

timersmanager 解析