Golang Timestamp.After方法代码示例

// ValueAtTime implements SeriesIterator.
func (it *memorySeriesIterator) ValueAtTime(t clientmodel.Timestamp) metric.Values {
	// 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 metric.Values{metric.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 metric.Values{metric.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 := metric.SamplePair{
			Timestamp: ts,
			Value:     it.chunkIt.sampleValueAtIndex(it.chunkIt.length() - 1),
		}
		it.chunkIt = it.chunkIterator(l - i + 1)
		return metric.Values{
			sp1,
			metric.SamplePair{
				Timestamp: it.chunkIt.timestampAtIndex(0),
				Value:     it.chunkIt.sampleValueAtIndex(0),
			},
		}
	}
	return it.chunkIt.valueAtTime(t)
}

// MayContain indicates whether the given SampleKey could potentially contain a
// value at the provided time.  Even if true is emitted, that does not mean a
// satisfactory value, in fact, exists.
func (s *SampleKey) MayContain(t clientmodel.Timestamp) bool {
	switch {
	case t.Before(s.FirstTimestamp):
		return false
	case t.After(s.LastTimestamp):
		return false
	default:
		return true
	}
}

// GetValueAtTime implements SeriesIterator.
func (it *memorySeriesIterator) GetValueAtTime(t clientmodel.Timestamp) metric.Values {
	it.lock()
	defer it.unlock()

	// The most common case. We are iterating through a chunk.
	if it.chunkIt != nil && it.chunkIt.contains(t) {
		return it.chunkIt.getValueAtTime(t)
	}

	it.chunkIt = nil

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

	// Before or exactly on the first sample of the series.
	if !t.After(it.chunks[0].firstTime()) {
		// return first value of first chunk
		return it.chunks[0].newIterator().getValueAtTime(t)
	}
	// After or exactly on the last sample of the series.
	if !t.Before(it.chunks[len(it.chunks)-1].lastTime()) {
		// return last value of last chunk
		return it.chunks[len(it.chunks)-1].newIterator().getValueAtTime(t)
	}

	// Find first chunk where lastTime() is after or equal to t.
	i := sort.Search(len(it.chunks), func(i int) bool {
		return !it.chunks[i].lastTime().Before(t)
	})
	if i == len(it.chunks) {
		panic("out of bounds")
	}

	if t.Before(it.chunks[i].firstTime()) {
		// We ended up between two chunks.
		return metric.Values{
			it.chunks[i-1].newIterator().getValueAtTime(t)[0],
			it.chunks[i].newIterator().getValueAtTime(t)[0],
		}
	}
	// We ended up in the middle of a chunk. We might stay there for a while,
	// so save it as the current chunk iterator.
	it.chunkIt = it.chunks[i].newIterator()
	return it.chunkIt.getValueAtTime(t)
}

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

func (t *TieredStorage) loadChunkAroundTime(
	iterator leveldb.Iterator,
	fingerprint *clientmodel.Fingerprint,
	ts clientmodel.Timestamp,
	firstBlock,
	lastBlock *SampleKey,
) (chunk metric.Values, expired bool) {
	if fingerprint.Less(firstBlock.Fingerprint) {
		return nil, false
	}
	if lastBlock.Fingerprint.Less(fingerprint) {
		return nil, true
	}

	seekingKey, _ := t.sampleKeys.Get()
	defer t.sampleKeys.Give(seekingKey)

	seekingKey.Fingerprint = fingerprint

	if fingerprint.Equal(firstBlock.Fingerprint) && ts.Before(firstBlock.FirstTimestamp) {
		seekingKey.FirstTimestamp = firstBlock.FirstTimestamp
	} else if fingerprint.Equal(lastBlock.Fingerprint) && ts.After(lastBlock.FirstTimestamp) {
		seekingKey.FirstTimestamp = lastBlock.FirstTimestamp
	} else {
		seekingKey.FirstTimestamp = ts
	}

	dto, _ := t.dtoSampleKeys.Get()
	defer t.dtoSampleKeys.Give(dto)

	seekingKey.Dump(dto)
	if !iterator.Seek(dto) {
		return chunk, true
	}

	var foundValues metric.Values

	if err := iterator.Key(dto); err != nil {
		panic(err)
	}
	seekingKey.Load(dto)

	if seekingKey.Fingerprint.Equal(fingerprint) {
		// Figure out if we need to rewind by one block.
		// Imagine the following supertime blocks with time ranges:
		//
		// Block 1: ft 1000 - lt 1009 <data>
		// Block 1: ft 1010 - lt 1019 <data>
		//
		// If we are aiming to find time 1005, we would first seek to the block with
		// supertime 1010, then need to rewind by one block by virtue of LevelDB
		// iterator seek behavior.
		//
		// Only do the rewind if there is another chunk before this one.
		if !seekingKey.MayContain(ts) {
			postValues := unmarshalValues(iterator.RawValue(), nil)
			if !seekingKey.Equal(firstBlock) {
				if !iterator.Previous() {
					panic("This should never return false.")
				}

				if err := iterator.Key(dto); err != nil {
					panic(err)
				}
				seekingKey.Load(dto)

				if !seekingKey.Fingerprint.Equal(fingerprint) {
					return postValues, false
				}

				foundValues = unmarshalValues(iterator.RawValue(), nil)
				foundValues = append(foundValues, postValues...)
				return foundValues, false
			}
		}

		foundValues = unmarshalValues(iterator.RawValue(), nil)
		return foundValues, false
	}

	if fingerprint.Less(seekingKey.Fingerprint) {
		if !seekingKey.Equal(firstBlock) {
			if !iterator.Previous() {
				panic("This should never return false.")
			}

			if err := iterator.Key(dto); err != nil {
				panic(err)
			}
			seekingKey.Load(dto)

			if !seekingKey.Fingerprint.Equal(fingerprint) {
				return nil, false
			}

			foundValues = unmarshalValues(iterator.RawValue(), nil)
			return foundValues, false
		}
	}

//.........这里部分代码省略.........

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

// contains implements chunkIterator.
func (it *deltaEncodedChunkIterator) contains(t clientmodel.Timestamp) bool {
	return !t.Before(it.chunk.firstTime()) && !t.After(it.chunk.lastTime())
}