// 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))
}
