func (t *TieredStorage) renderView(viewJob viewJob) {
// Telemetry.
var err error
begin := time.Now()
defer func() {
t.memorySemaphore <- true
duration := time.Since(begin)
recordOutcome(
duration,
err,
map[string]string{operation: renderView, result: success},
map[string]string{operation: renderView, result: failure},
)
}()
view := newView()
var iterator leveldb.Iterator
diskPresent := true
firstBlock, _ := t.sampleKeys.Get()
defer t.sampleKeys.Give(firstBlock)
lastBlock, _ := t.sampleKeys.Get()
defer t.sampleKeys.Give(lastBlock)
sampleKeyDto, _ := t.dtoSampleKeys.Get()
defer t.dtoSampleKeys.Give(sampleKeyDto)
defer func() {
// Give back all ops not yet popped.
for viewJob.builder.HasOp() {
giveBackOp(viewJob.builder.PopOp())
}
}()
extractionTimer := viewJob.stats.GetTimer(stats.ViewDataExtractionTime).Start()
for viewJob.builder.HasOp() {
op := viewJob.builder.PopOp()
defer giveBackOp(op)
fp := op.Fingerprint()
old, err := t.seriesTooOld(fp, op.CurrentTime())
if err != nil {
glog.Errorf("Error getting watermark from cache for %s: %s", fp, err)
continue
}
if old {
continue
}
memValues := t.memoryArena.CloneSamples(fp)
for !op.Consumed() {
// Abort the view rendering if the caller (makeView) has timed out.
if len(viewJob.abort) > 0 {
return
}
// Load data value chunk(s) around the current time.
targetTime := op.CurrentTime()
currentChunk := chunk{}
// If we aimed before the oldest value in memory, load more data from disk.
if (len(memValues) == 0 || memValues.FirstTimeAfter(targetTime)) && diskPresent {
if iterator == nil {
// Get a single iterator that will be used for all data extraction
// below.
iterator, _ = t.DiskStorage.MetricSamples.NewIterator(true)
defer iterator.Close()
if diskPresent = iterator.SeekToLast(); diskPresent {
if err := iterator.Key(sampleKeyDto); err != nil {
panic(err)
}
lastBlock.Load(sampleKeyDto)
if !iterator.SeekToFirst() {
diskPresent = false
} else {
if err := iterator.Key(sampleKeyDto); err != nil {
panic(err)
}
firstBlock.Load(sampleKeyDto)
}
}
}
if diskPresent {
diskTimer := viewJob.stats.GetTimer(stats.ViewDiskExtractionTime).Start()
diskValues, expired := t.loadChunkAroundTime(
iterator,
fp,
targetTime,
firstBlock,
lastBlock,
)
if expired {
diskPresent = false
}
diskTimer.Stop()
// If we aimed past the newest value on disk,
// combine it with the next value from memory.
if len(diskValues) == 0 {
currentChunk = chunk(memValues)
} else {
if len(memValues) > 0 && diskValues.LastTimeBefore(targetTime) {
latestDiskValue := diskValues[len(diskValues)-1:]
currentChunk = append(chunk(latestDiskValue), chunk(memValues)...)
} else {
currentChunk = chunk(diskValues)
}
}
} else {
currentChunk = chunk(memValues)
}
} else {
currentChunk = chunk(memValues)
}
// There's no data at all for this fingerprint, so stop processing.
if len(currentChunk) == 0 {
break
}
currentChunk = currentChunk.TruncateBefore(targetTime)
lastChunkTime := currentChunk[len(currentChunk)-1].Timestamp
if lastChunkTime.After(targetTime) {
targetTime = lastChunkTime
}
if op.CurrentTime().After(targetTime) {
break
}
// Extract all needed data from the current chunk and append the
// extracted samples to the materialized view.
for !op.Consumed() && !op.CurrentTime().After(targetTime) {
view.appendSamples(fp, op.ExtractSamples(metric.Values(currentChunk)))
}
}
}
extractionTimer.Stop()
viewJob.output <- view
return
}
