Golang Time.After方法代码示例

// findAtOrBefore implements Iterator.
func (it *varbitChunkIterator) FindAtOrBefore(t model.Time) bool {
	if it.len == 0 || t.Before(it.c.FirstTime()) {
		return false
	}
	last := it.c.lastTime()
	if !t.Before(last) {
		it.t = last
		it.v = it.c.lastValue()
		it.pos = it.len + 1
		return true
	}
	if t == it.t {
		return it.lastError == nil
	}
	if t.Before(it.t) || it.rewound {
		it.reset()
	}

	var (
		prevT = model.Earliest
		prevV model.SampleValue
	)
	for it.Scan() && t.After(it.t) {
		prevT = it.t
		prevV = it.v
		// TODO(beorn7): If we are in a repeat, we could iterate forward
		// much faster.
	}
	if t == it.t {
		return it.lastError == nil
	}
	it.rewind(prevT, prevV)
	return it.lastError == nil
}

// preloadChunksForInstant preloads chunks for the latest value in the given
// range. If the last sample saved in the memorySeries itself is the latest
// value in the given range, it will in fact preload zero chunks and just take
// that value.
func (s *memorySeries) preloadChunksForInstant(
	fp model.Fingerprint,
	from model.Time, through model.Time,
	mss *MemorySeriesStorage,
) (SeriesIterator, error) {
	// If we have a lastSamplePair in the series, and thas last samplePair
	// is in the interval, just take it in a singleSampleSeriesIterator. No
	// need to pin or load anything.
	lastSample := s.lastSamplePair()
	if !through.Before(lastSample.Timestamp) &&
		!from.After(lastSample.Timestamp) &&
		lastSample != model.ZeroSamplePair {
		iter := &boundedIterator{
			it: &singleSampleSeriesIterator{
				samplePair: lastSample,
				metric:     s.metric,
			},
			start: model.Now().Add(-mss.dropAfter),
		}
		return iter, nil
	}
	// If we are here, we are out of luck and have to delegate to the more
	// expensive method.
	return s.preloadChunksForRange(fp, from, through, mss)
}

// ValueAtTime implements SeriesIterator.
func (it *memorySeriesIterator) ValueAtTime(t model.Time) []model.SamplePair {
	// The most common case. We are iterating through a chunk.
	if it.chunkIt != nil && it.chunkIt.contains(t) {
		return it.chunkIt.valueAtTime(t)
	}

	if len(it.chunks) == 0 {
		return nil
	}

	// Before or exactly on the first sample of the series.
	it.chunkIt = it.chunkIterator(0)
	ts := it.chunkIt.timestampAtIndex(0)
	if !t.After(ts) {
		// return first value of first chunk
		return []model.SamplePair{{
			Timestamp: ts,
			Value:     it.chunkIt.sampleValueAtIndex(0),
		}}
	}

	// After or exactly on the last sample of the series.
	it.chunkIt = it.chunkIterator(len(it.chunks) - 1)
	ts = it.chunkIt.lastTimestamp()
	if !t.Before(ts) {
		// return last value of last chunk
		return []model.SamplePair{{
			Timestamp: ts,
			Value:     it.chunkIt.sampleValueAtIndex(it.chunkIt.length() - 1),
		}}
	}

	// Find last chunk where firstTime() is before or equal to t.
	l := len(it.chunks) - 1
	i := sort.Search(len(it.chunks), func(i int) bool {
		return !it.chunks[l-i].firstTime().After(t)
	})
	if i == len(it.chunks) {
		panic("out of bounds")
	}
	it.chunkIt = it.chunkIterator(l - i)
	ts = it.chunkIt.lastTimestamp()
	if t.After(ts) {
		// We ended up between two chunks.
		sp1 := model.SamplePair{
			Timestamp: ts,
			Value:     it.chunkIt.sampleValueAtIndex(it.chunkIt.length() - 1),
		}
		it.chunkIt = it.chunkIterator(l - i + 1)
		return []model.SamplePair{
			sp1,
			{
				Timestamp: it.chunkIt.timestampAtIndex(0),
				Value:     it.chunkIt.sampleValueAtIndex(0),
			},
		}
	}
	return it.chunkIt.valueAtTime(t)
}

// contains implements Iterator.
func (it *varbitChunkIterator) Contains(t model.Time) (bool, error) {
	last, err := it.LastTimestamp()
	if err != nil {
		it.lastError = err
		return false, err
	}
	return !t.Before(it.c.FirstTime()) &&
		!t.After(last), it.lastError
}

// metricForRange returns the metric for the given fingerprint if the
// corresponding time series has samples between 'from' and 'through', together
// with a pointer to the series if it is in memory already. For a series that
// does not have samples between 'from' and 'through', the returned bool is
// false. For an archived series that does contain samples between 'from' and
// 'through', it returns (metric, nil, true).
//
// The caller must have locked the fp.
func (s *memorySeriesStorage) metricForRange(
	fp model.Fingerprint,
	from, through model.Time,
) (model.Metric, *memorySeries, bool) {
	series, ok := s.fpToSeries.get(fp)
	if ok {
		if series.lastTime.Before(from) || series.firstTime().After(through) {
			return nil, nil, false
		}
		return series.metric, series, true
	}
	// From here on, we are only concerned with archived metrics.
	// If the high watermark of archived series is before 'from', we are done.
	watermark := model.Time(atomic.LoadInt64((*int64)(&s.archiveHighWatermark)))
	if watermark < from {
		return nil, nil, false
	}
	if from.After(model.Earliest) || through.Before(model.Latest) {
		// The range lookup is relatively cheap, so let's do it first if
		// we have a chance the archived metric is not in the range.
		has, first, last := s.persistence.hasArchivedMetric(fp)
		if !has {
			s.nonExistentSeriesMatchesCount.Inc()
			return nil, nil, false
		}
		if first.After(through) || last.Before(from) {
			return nil, nil, false
		}
	}

	metric, err := s.persistence.archivedMetric(fp)
	if err != nil {
		// archivedMetric has already flagged the storage as dirty in this case.
		return nil, nil, false
	}
	return metric, nil, true
}

// findAtOrAfter implements Iterator.
func (it *varbitChunkIterator) FindAtOrAfter(t model.Time) bool {
	if it.len == 0 || t.After(it.c.lastTime()) {
		return false
	}
	first := it.c.FirstTime()
	if !t.After(first) {
		it.reset()
		return it.Scan()
	}
	if t == it.t {
		return it.lastError == nil
	}
	if t.Before(it.t) {
		it.reset()
	}
	for it.Scan() && t.After(it.t) {
		// TODO(beorn7): If we are in a repeat, we could iterate forward
		// much faster.
	}
	return it.lastError == nil
}

func (cd *chunkDesc) contains(t model.Time) bool {
	return !t.Before(cd.firstTime()) && !t.After(cd.lastTime())
}

// contains implements Iterator.
func (it *indexAccessingChunkIterator) Contains(t model.Time) (bool, error) {
	return !t.Before(it.acc.timestampAtIndex(0)) &&
		!t.After(it.acc.timestampAtIndex(it.len-1)), it.acc.err()
}

// contains implements chunkIterator.
func (it *doubleDeltaEncodedChunkIterator) contains(t model.Time) bool {
	return !t.Before(it.baseT) && !t.After(it.timestampAtIndex(it.len-1))
}