// 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
}
}
// InsideInterval indicates whether a given range of sorted values could contain
// a value for a given time.
func (v Values) InsideInterval(t clientmodel.Timestamp) bool {
switch {
case v.Len() == 0:
return false
case t.Before(v[0].Timestamp):
return false
case !v[v.Len()-1].Timestamp.Before(t):
return false
default:
return true
}
}
func buildValues(firstValue clientmodel.SampleValue, from, to clientmodel.Timestamp, interval time.Duration) (v metric.Values) {
for from.Before(to) {
v = append(v, metric.SamplePair{
Value: firstValue,
Timestamp: from,
})
from = from.Add(interval)
firstValue++
}
return
}
func buildSamples(from, to clientmodel.Timestamp, interval time.Duration, m clientmodel.Metric) (v clientmodel.Samples) {
i := clientmodel.SampleValue(0)
for from.Before(to) {
v = append(v, &clientmodel.Sample{
Metric: m,
Value: i,
Timestamp: from,
})
from = from.Add(interval)
i++
}
return
}
// 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)
}
// preloadChunksForRange loads chunks for the given range from the persistence.
// The caller must have locked the fingerprint of the series.
func (s *memorySeries) preloadChunksForRange(
from clientmodel.Timestamp, through clientmodel.Timestamp,
fp clientmodel.Fingerprint, mss *memorySeriesStorage,
) ([]*chunkDesc, error) {
firstChunkDescTime := clientmodel.Latest
if len(s.chunkDescs) > 0 {
firstChunkDescTime = s.chunkDescs[0].firstTime()
}
if s.chunkDescsOffset != 0 && from.Before(firstChunkDescTime) {
cds, err := mss.loadChunkDescs(fp, firstChunkDescTime)
if err != nil {
return nil, err
}
s.chunkDescs = append(cds, s.chunkDescs...)
s.chunkDescsOffset = 0
s.persistWatermark += len(cds)
}
if len(s.chunkDescs) == 0 {
return nil, nil
}
// Find first chunk with start time after "from".
fromIdx := sort.Search(len(s.chunkDescs), func(i int) bool {
return s.chunkDescs[i].firstTime().After(from)
})
// Find first chunk with start time after "through".
throughIdx := sort.Search(len(s.chunkDescs), func(i int) bool {
return s.chunkDescs[i].firstTime().After(through)
})
if fromIdx > 0 {
fromIdx--
}
if throughIdx == len(s.chunkDescs) {
throughIdx--
}
pinIndexes := make([]int, 0, throughIdx-fromIdx+1)
for i := fromIdx; i <= throughIdx; i++ {
pinIndexes = append(pinIndexes, i)
}
return s.preloadChunks(pinIndexes, fp, mss)
}
// Apply implements the Processor interface.
func (p *CompactionProcessor) Apply(sampleIterator leveldb.Iterator, samplesPersistence raw.Persistence, stopAt clientmodel.Timestamp, fingerprint *clientmodel.Fingerprint) (lastCurated clientmodel.Timestamp, err error) {
var pendingBatch raw.Batch
defer func() {
if pendingBatch != nil {
pendingBatch.Close()
}
}()
var pendingMutations = 0
var pendingSamples metric.Values
var unactedSamples metric.Values
var lastTouchedTime clientmodel.Timestamp
var keyDropped bool
sampleKey, _ := p.sampleKeys.Get()
defer p.sampleKeys.Give(sampleKey)
sampleKeyDto, _ := p.dtoSampleKeys.Get()
defer p.dtoSampleKeys.Give(sampleKeyDto)
if err = sampleIterator.Key(sampleKeyDto); err != nil {
return
}
sampleKey.Load(sampleKeyDto)
unactedSamples = unmarshalValues(sampleIterator.RawValue(), nil)
for lastCurated.Before(stopAt) && lastTouchedTime.Before(stopAt) && sampleKey.Fingerprint.Equal(fingerprint) {
switch {
// Furnish a new pending batch operation if none is available.
case pendingBatch == nil:
pendingBatch = leveldb.NewBatch()
// If there are no sample values to extract from the datastore, let's
// continue extracting more values to use. We know that the time.Before()
// block would prevent us from going into unsafe territory.
case len(unactedSamples) == 0:
if !sampleIterator.Next() {
return lastCurated, fmt.Errorf("illegal condition: invalid iterator on continuation")
}
keyDropped = false
if err = sampleIterator.Key(sampleKeyDto); err != nil {
return
}
sampleKey.Load(sampleKeyDto)
if !sampleKey.Fingerprint.Equal(fingerprint) {
break
}
unactedSamples = unmarshalValues(sampleIterator.RawValue(), nil)
// If the number of pending mutations exceeds the allowed batch amount,
// commit to disk and delete the batch. A new one will be recreated if
// necessary.
case pendingMutations >= p.maximumMutationPoolBatch:
err = samplesPersistence.Commit(pendingBatch)
if err != nil {
return
}
pendingMutations = 0
pendingBatch.Close()
pendingBatch = nil
case len(pendingSamples) == 0 && len(unactedSamples) >= p.minimumGroupSize:
lastTouchedTime = unactedSamples[len(unactedSamples)-1].Timestamp
unactedSamples = metric.Values{}
case len(pendingSamples)+len(unactedSamples) < p.minimumGroupSize:
if !keyDropped {
k := &dto.SampleKey{}
sampleKey.Dump(k)
pendingBatch.Drop(k)
keyDropped = true
}
pendingSamples = append(pendingSamples, unactedSamples...)
lastTouchedTime = unactedSamples[len(unactedSamples)-1].Timestamp
unactedSamples = metric.Values{}
pendingMutations++
// If the number of pending writes equals the target group size
case len(pendingSamples) == p.minimumGroupSize:
k := &dto.SampleKey{}
newSampleKey := buildSampleKey(fingerprint, pendingSamples)
newSampleKey.Dump(k)
b := marshalValues(pendingSamples, nil)
pendingBatch.PutRaw(k, b)
pendingMutations++
lastCurated = newSampleKey.FirstTimestamp
if len(unactedSamples) > 0 {
if !keyDropped {
sampleKey.Dump(k)
pendingBatch.Drop(k)
keyDropped = true
}
if len(unactedSamples) > p.minimumGroupSize {
pendingSamples = unactedSamples[:p.minimumGroupSize]
unactedSamples = unactedSamples[p.minimumGroupSize:]
lastTouchedTime = unactedSamples[len(unactedSamples)-1].Timestamp
} else {
pendingSamples = unactedSamples
lastTouchedTime = pendingSamples[len(pendingSamples)-1].Timestamp
unactedSamples = metric.Values{}
}
}
case len(pendingSamples)+len(unactedSamples) >= p.minimumGroupSize:
if !keyDropped {
k := &dto.SampleKey{}
sampleKey.Dump(k)
pendingBatch.Drop(k)
keyDropped = true
}
remainder := p.minimumGroupSize - len(pendingSamples)
pendingSamples = append(pendingSamples, unactedSamples[:remainder]...)
unactedSamples = unactedSamples[remainder:]
if len(unactedSamples) == 0 {
lastTouchedTime = pendingSamples[len(pendingSamples)-1].Timestamp
} else {
lastTouchedTime = unactedSamples[len(unactedSamples)-1].Timestamp
}
pendingMutations++
default:
err = fmt.Errorf("unhandled processing case")
}
}
if len(unactedSamples) > 0 || len(pendingSamples) > 0 {
pendingSamples = append(pendingSamples, unactedSamples...)
k := &dto.SampleKey{}
newSampleKey := buildSampleKey(fingerprint, pendingSamples)
newSampleKey.Dump(k)
b := marshalValues(pendingSamples, nil)
pendingBatch.PutRaw(k, b)
pendingSamples = metric.Values{}
pendingMutations++
lastCurated = newSampleKey.FirstTimestamp
}
// This is not deferred due to the off-chance that a pre-existing commit
// failed.
if pendingBatch != nil && pendingMutations > 0 {
err = samplesPersistence.Commit(pendingBatch)
if err != nil {
return
}
}
return
}
// 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
}
}
panic("illegal state: violated sort invariant")
}
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())
}
