我目前正在为 natvis 中的日期类型编写可视化工具。date 类型以通常的 unix 方式存储自 1970 年以来的秒数,但如果不使用临时变量,则从中派生年、月和月中的日期会非常冗长。我希望能够存储工作变量,以便以理智的方式评估可视化器。这可能吗?
我到达的解决方案如下所示:
struct SLowResAbsoluteTime
{
SLowResAbsoluteTime() : mTime(0) { calcDOE(); }
SLowResAbsoluteTime(int year, SDate::EMonth m, SDate::EDayOfWeek day, UINT8 hour, UINT8 minute, UINT8 seconds);
SLowResAbsoluteTime(const SDate &date);
SLowResAbsoluteTime(unsigned long long time) : mTime(time) { calcDOE(); }
SLowResAbsoluteTime(const SLowResAbsoluteTime &other) : mTime(other.mTime) { calcDOE(); }
SDate getDate() const; //calculate date object from given time
UINT32 getHour() const;
UINT32 getMinutes() const;
UINT32 getSeconds() const;
bool operator < (const SLowResAbsoluteTime &other) const { return mTime < other.mTime; }
bool operator > (const SLowResAbsoluteTime &other) const { return mTime > other.mTime; }
bool operator <= (const SLowResAbsoluteTime &other) const { return mTime <= other.mTime; }
bool operator >= (const SLowResAbsoluteTime &other) const { return mTime >= other.mTime; }
bool operator == (const SLowResAbsoluteTime &other) const { return mTime == other.mTime; }
bool operator != (const SLowResAbsoluteTime &other) const { return mTime != other.mTime; }
SLowResAbsoluteTime operator -(const SLowResAbsoluteTime &time) const { return SLowResAbsoluteTime(mTime - time.mTime); }
SLowResAbsoluteTime operator +(const SLowResAbsoluteTime &time) const { return SLowResAbsoluteTime(mTime + time.mTime); }
const SLowResAbsoluteTime &operator -=(const SLowResAbsoluteTime &time) { mTime -= time.mTime; return *this; }
const SLowResAbsoluteTime &operator +=(const SLowResAbsoluteTime &time) { mTime += time.mTime; return *this; }
unsigned long long mTime;
void invalidate() { mTime = -1; }
bool isValid() const {return mTime != UINT64(-1); }
operator unsigned long() const { return (long)mTime; }
void calcDOE();
#ifdef USING_DEBUG_TIMER_DOE
struct { UINT16 y; UINT8 m; UINT8 d; } mDOE;
#endif
};
请注意“USING_DEBUG_TIMER_DOE”部分。是这样计算的:
void SLowResAbsoluteTime::calcDOE()
{
#ifdef USING_DEBUG_TIMER_DOE
int ts = mTime / (60 * 60 * 24);
int z = ts + 719468;
int doe = (z - ((z >= 0 ? z : z - 146096) / 146097) * 146097);
int yoe = (doe - doe / 1460 + doe / 36524 - doe / 146096) / 365; // [0, 399]
int era = (z >= 0 ? z : z - 146096) / 146097;
int y = (yoe) + era * 400;
int doy = doe - (365 * yoe + yoe / 4 - yoe / 100); // [0, 365]
int mp = (5 * doy + 2) / 153; // [0, 11]
int d = doy - (153 * mp + 2) / 5 + 1; // [1, 31]
int m = mp + (mp < 10 ? 3 : -9); // [1, 12]
mDOE.y = y + (m <= 2);
mDOE.m = m;
mDOE.d = d;
#endif
}
用于可视化这些的 natvis 是:
<Type Name="SLowResAbsoluteTime">
<DisplayString>{{time = { (mTime / (60 * 60)) % 24 }:{(mTime / 60) % 60}:{mTime % 60} } day-1970: {mTime / (60 * 60 * 24)} }</DisplayString>
<Expand>
<Item Name="month">(int)mDOE.m</Item>
<Item Name="day">(int)mDOE.d</Item>-->
<Item Name="secs since 1/1/1970"> mTime</Item>
</Expand>
</Type>