mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-26 20:30:10 +01:00
244c23ea2c
This should reduce memory usage under high time series churn rate
542 lines
16 KiB
Go
542 lines
16 KiB
Go
package promql
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import (
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"crypto/rand"
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"flag"
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"fmt"
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"sync"
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"sync/atomic"
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"time"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/auth"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/memory"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/workingsetcache"
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"github.com/VictoriaMetrics/fastcache"
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"github.com/VictoriaMetrics/metrics"
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"github.com/VictoriaMetrics/metricsql"
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)
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var (
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cacheTimestampOffset = flag.Duration("search.cacheTimestampOffset", 5*time.Minute, "The maximum duration since the current time for response data, "+
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"which is always queried from the original raw data, without using the response cache. Increase this value if you see gaps in responses "+
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"due to time synchronization issues between VictoriaMetrics and data sources")
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)
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var rollupResultCacheV = &rollupResultCache{
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c: workingsetcache.New(1024 * 1024), // This is a cache for testing.
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}
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var rollupResultCachePath string
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func getRollupResultCacheSize() int {
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rollupResultCacheSizeOnce.Do(func() {
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n := memory.Allowed() / 8
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if n <= 0 {
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n = 1024 * 1024
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}
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rollupResultCacheSize = n
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})
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return rollupResultCacheSize
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}
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var (
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rollupResultCacheSize int
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rollupResultCacheSizeOnce sync.Once
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)
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// InitRollupResultCache initializes the rollupResult cache
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//
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// if cachePath is empty, then the cache isn't stored to persistent disk.
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func InitRollupResultCache(cachePath string) {
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rollupResultCachePath = cachePath
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startTime := time.Now()
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cacheSize := getRollupResultCacheSize()
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var c *workingsetcache.Cache
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if len(rollupResultCachePath) > 0 {
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logger.Infof("loading rollupResult cache from %q...", rollupResultCachePath)
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c = workingsetcache.Load(rollupResultCachePath, cacheSize)
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} else {
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c = workingsetcache.New(cacheSize)
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}
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if *disableCache {
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c.Reset()
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}
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stats := &fastcache.Stats{}
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var statsLock sync.Mutex
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var statsLastUpdate uint64
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fcs := func() *fastcache.Stats {
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statsLock.Lock()
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defer statsLock.Unlock()
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if fasttime.UnixTimestamp()-statsLastUpdate < 2 {
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return stats
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}
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var fcs fastcache.Stats
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c.UpdateStats(&fcs)
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stats = &fcs
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statsLastUpdate = fasttime.UnixTimestamp()
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return stats
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}
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if len(rollupResultCachePath) > 0 {
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logger.Infof("loaded rollupResult cache from %q in %.3f seconds; entriesCount: %d, sizeBytes: %d",
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rollupResultCachePath, time.Since(startTime).Seconds(), fcs().EntriesCount, fcs().BytesSize)
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}
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metrics.NewGauge(`vm_cache_entries{type="promql/rollupResult"}`, func() float64 {
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return float64(fcs().EntriesCount)
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})
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metrics.NewGauge(`vm_cache_size_bytes{type="promql/rollupResult"}`, func() float64 {
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return float64(fcs().BytesSize)
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})
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metrics.NewGauge(`vm_cache_requests_total{type="promql/rollupResult"}`, func() float64 {
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return float64(fcs().GetCalls)
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})
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metrics.NewGauge(`vm_cache_misses_total{type="promql/rollupResult"}`, func() float64 {
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return float64(fcs().Misses)
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})
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rollupResultCacheV = &rollupResultCache{
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c: c,
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}
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}
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// StopRollupResultCache closes the rollupResult cache.
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func StopRollupResultCache() {
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if len(rollupResultCachePath) == 0 {
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rollupResultCacheV.c.Stop()
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rollupResultCacheV.c = nil
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return
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}
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logger.Infof("saving rollupResult cache to %q...", rollupResultCachePath)
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startTime := time.Now()
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if err := rollupResultCacheV.c.Save(rollupResultCachePath); err != nil {
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logger.Errorf("cannot close rollupResult cache at %q: %s", rollupResultCachePath, err)
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return
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}
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var fcs fastcache.Stats
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rollupResultCacheV.c.UpdateStats(&fcs)
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rollupResultCacheV.c.Stop()
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rollupResultCacheV.c = nil
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logger.Infof("saved rollupResult cache to %q in %.3f seconds; entriesCount: %d, sizeBytes: %d",
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rollupResultCachePath, time.Since(startTime).Seconds(), fcs.EntriesCount, fcs.BytesSize)
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}
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// TODO: convert this cache to distributed cache shared among vmselect
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// instances in the cluster.
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type rollupResultCache struct {
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c *workingsetcache.Cache
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}
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var rollupResultCacheResets = metrics.NewCounter(`vm_cache_resets_total{type="promql/rollupResult"}`)
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// ResetRollupResultCache resets rollup result cache.
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func ResetRollupResultCache() {
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rollupResultCacheResets.Inc()
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atomic.AddUint64(&rollupResultCacheKeyPrefix, 1)
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logger.Infof("rollupResult cache has been cleared")
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}
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func (rrc *rollupResultCache) Get(ec *EvalConfig, expr metricsql.Expr, window int64) (tss []*timeseries, newStart int64) {
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if !ec.mayCache() {
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return nil, ec.Start
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}
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// Obtain tss from the cache.
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bb := bbPool.Get()
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defer bbPool.Put(bb)
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bb.B = marshalRollupResultCacheKey(bb.B[:0], ec.AuthToken, expr, window, ec.Step, ec.EnforcedTagFilterss)
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metainfoBuf := rrc.c.Get(nil, bb.B)
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if len(metainfoBuf) == 0 {
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return nil, ec.Start
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}
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var mi rollupResultCacheMetainfo
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if err := mi.Unmarshal(metainfoBuf); err != nil {
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logger.Panicf("BUG: cannot unmarshal rollupResultCacheMetainfo: %s; it looks like it was improperly saved", err)
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}
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key := mi.GetBestKey(ec.Start, ec.End)
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if key.prefix == 0 && key.suffix == 0 {
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return nil, ec.Start
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}
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bb.B = key.Marshal(bb.B[:0])
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compressedResultBuf := resultBufPool.Get()
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defer resultBufPool.Put(compressedResultBuf)
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compressedResultBuf.B = rrc.c.GetBig(compressedResultBuf.B[:0], bb.B)
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if len(compressedResultBuf.B) == 0 {
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mi.RemoveKey(key)
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metainfoBuf = mi.Marshal(metainfoBuf[:0])
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bb.B = marshalRollupResultCacheKey(bb.B[:0], ec.AuthToken, expr, window, ec.Step, ec.EnforcedTagFilterss)
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rrc.c.Set(bb.B, metainfoBuf)
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return nil, ec.Start
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}
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// Decompress into newly allocated byte slice, since tss returned from unmarshalTimeseriesFast
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// refers to the byte slice, so it cannot be returned to the resultBufPool.
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resultBuf, err := encoding.DecompressZSTD(nil, compressedResultBuf.B)
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if err != nil {
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logger.Panicf("BUG: cannot decompress resultBuf from rollupResultCache: %s; it looks like it was improperly saved", err)
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}
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tss, err = unmarshalTimeseriesFast(resultBuf)
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if err != nil {
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logger.Panicf("BUG: cannot unmarshal timeseries from rollupResultCache: %s; it looks like it was improperly saved", err)
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}
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// Extract values for the matching timestamps
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timestamps := tss[0].Timestamps
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i := 0
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for i < len(timestamps) && timestamps[i] < ec.Start {
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i++
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}
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if i == len(timestamps) {
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// no matches.
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return nil, ec.Start
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}
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if timestamps[i] != ec.Start {
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// The cached range doesn't cover the requested range.
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return nil, ec.Start
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}
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j := len(timestamps) - 1
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for j >= 0 && timestamps[j] > ec.End {
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j--
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}
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j++
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if j <= i {
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// no matches.
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return nil, ec.Start
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}
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for _, ts := range tss {
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ts.Timestamps = ts.Timestamps[i:j]
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ts.Values = ts.Values[i:j]
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}
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timestamps = tss[0].Timestamps
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newStart = timestamps[len(timestamps)-1] + ec.Step
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return tss, newStart
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}
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var resultBufPool bytesutil.ByteBufferPool
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func (rrc *rollupResultCache) Put(ec *EvalConfig, expr metricsql.Expr, window int64, tss []*timeseries) {
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if len(tss) == 0 || !ec.mayCache() {
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return
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}
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// Remove values up to currentTime - step - cacheTimestampOffset,
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// since these values may be added later.
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timestamps := tss[0].Timestamps
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deadline := (time.Now().UnixNano() / 1e6) - ec.Step - cacheTimestampOffset.Milliseconds()
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i := len(timestamps) - 1
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for i >= 0 && timestamps[i] > deadline {
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i--
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}
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i++
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if i == 0 {
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// Nothing to store in the cache.
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return
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}
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if i < len(timestamps) {
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timestamps = timestamps[:i]
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// Make a copy of tss and remove unfit values
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rvs := copyTimeseriesShallow(tss)
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for _, ts := range rvs {
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ts.Timestamps = ts.Timestamps[:i]
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ts.Values = ts.Values[:i]
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}
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tss = rvs
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}
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// Store tss in the cache.
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maxMarshaledSize := getRollupResultCacheSize() / 4
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resultBuf := resultBufPool.Get()
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defer resultBufPool.Put(resultBuf)
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resultBuf.B = marshalTimeseriesFast(resultBuf.B[:0], tss, maxMarshaledSize, ec.Step)
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if len(resultBuf.B) == 0 {
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tooBigRollupResults.Inc()
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return
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}
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compressedResultBuf := resultBufPool.Get()
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defer resultBufPool.Put(compressedResultBuf)
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compressedResultBuf.B = encoding.CompressZSTDLevel(compressedResultBuf.B[:0], resultBuf.B, 1)
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bb := bbPool.Get()
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defer bbPool.Put(bb)
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var key rollupResultCacheKey
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key.prefix = rollupResultCacheKeyPrefix
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key.suffix = atomic.AddUint64(&rollupResultCacheKeySuffix, 1)
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bb.B = key.Marshal(bb.B[:0])
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rrc.c.SetBig(bb.B, compressedResultBuf.B)
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bb.B = marshalRollupResultCacheKey(bb.B[:0], ec.AuthToken, expr, window, ec.Step, ec.EnforcedTagFilterss)
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metainfoBuf := rrc.c.Get(nil, bb.B)
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var mi rollupResultCacheMetainfo
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if len(metainfoBuf) > 0 {
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if err := mi.Unmarshal(metainfoBuf); err != nil {
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logger.Panicf("BUG: cannot unmarshal rollupResultCacheMetainfo: %s; it looks like it was improperly saved", err)
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}
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}
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mi.AddKey(key, timestamps[0], timestamps[len(timestamps)-1])
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metainfoBuf = mi.Marshal(metainfoBuf[:0])
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rrc.c.Set(bb.B, metainfoBuf)
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}
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var (
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rollupResultCacheKeyPrefix = func() uint64 {
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var buf [8]byte
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if _, err := rand.Read(buf[:]); err != nil {
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// do not use logger.Panicf, since it isn't initialized yet.
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panic(fmt.Errorf("FATAL: cannot read random data for rollupResultCacheKeyPrefix: %w", err))
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}
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return encoding.UnmarshalUint64(buf[:])
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}()
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rollupResultCacheKeySuffix = uint64(time.Now().UnixNano())
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)
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var tooBigRollupResults = metrics.NewCounter("vm_too_big_rollup_results_total")
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// Increment this value every time the format of the cache changes.
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const rollupResultCacheVersion = 8
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func marshalRollupResultCacheKey(dst []byte, at *auth.Token, expr metricsql.Expr, window, step int64, etfs [][]storage.TagFilter) []byte {
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dst = append(dst, rollupResultCacheVersion)
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dst = encoding.MarshalUint64(dst, rollupResultCacheKeyPrefix)
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dst = encoding.MarshalUint32(dst, at.AccountID)
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dst = encoding.MarshalUint32(dst, at.ProjectID)
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dst = encoding.MarshalInt64(dst, window)
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dst = encoding.MarshalInt64(dst, step)
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dst = expr.AppendString(dst)
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for i, etf := range etfs {
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for _, f := range etf {
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dst = f.Marshal(dst)
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}
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if i+1 < len(etfs) {
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dst = append(dst, '|')
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}
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}
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return dst
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}
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// mergeTimeseries concatenates b with a and returns the result.
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//
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// Preconditions:
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// - a mustn't intersect with b.
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// - a timestamps must be smaller than b timestamps.
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//
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// Postconditions:
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// - a and b cannot be used after returning from the call.
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func mergeTimeseries(a, b []*timeseries, bStart int64, ec *EvalConfig) []*timeseries {
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sharedTimestamps := ec.getSharedTimestamps()
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if bStart == ec.Start {
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// Nothing to merge - b covers all the time range.
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// Verify b is correct.
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for _, tsB := range b {
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tsB.denyReuse = true
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tsB.Timestamps = sharedTimestamps
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if len(tsB.Values) != len(tsB.Timestamps) {
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logger.Panicf("BUG: unexpected number of values in b; got %d; want %d", len(tsB.Values), len(tsB.Timestamps))
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}
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}
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return b
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}
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m := make(map[string]*timeseries, len(a))
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bb := bbPool.Get()
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defer bbPool.Put(bb)
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for _, ts := range a {
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bb.B = marshalMetricNameSorted(bb.B[:0], &ts.MetricName)
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m[string(bb.B)] = ts
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}
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rvs := make([]*timeseries, 0, len(a))
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for _, tsB := range b {
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var tmp timeseries
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tmp.denyReuse = true
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tmp.Timestamps = sharedTimestamps
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tmp.Values = make([]float64, 0, len(tmp.Timestamps))
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// Do not use MetricName.CopyFrom for performance reasons.
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// It is safe to make shallow copy, since tsB must no longer used.
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tmp.MetricName = tsB.MetricName
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bb.B = marshalMetricNameSorted(bb.B[:0], &tsB.MetricName)
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tsA := m[string(bb.B)]
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if tsA == nil {
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tStart := ec.Start
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for tStart < bStart {
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tmp.Values = append(tmp.Values, nan)
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tStart += ec.Step
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}
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} else {
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tmp.Values = append(tmp.Values, tsA.Values...)
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delete(m, string(bb.B))
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}
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tmp.Values = append(tmp.Values, tsB.Values...)
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if len(tmp.Values) != len(tmp.Timestamps) {
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logger.Panicf("BUG: unexpected values after merging new values; got %d; want %d", len(tmp.Values), len(tmp.Timestamps))
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}
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rvs = append(rvs, &tmp)
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}
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// Copy the remaining timeseries from m.
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for _, tsA := range m {
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var tmp timeseries
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tmp.denyReuse = true
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tmp.Timestamps = sharedTimestamps
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// Do not use MetricName.CopyFrom for performance reasons.
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// It is safe to make shallow copy, since tsA must no longer used.
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tmp.MetricName = tsA.MetricName
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tmp.Values = append(tmp.Values, tsA.Values...)
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tStart := bStart
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for tStart <= ec.End {
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tmp.Values = append(tmp.Values, nan)
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tStart += ec.Step
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}
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if len(tmp.Values) != len(tmp.Timestamps) {
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logger.Panicf("BUG: unexpected values in the result after adding cached values; got %d; want %d", len(tmp.Values), len(tmp.Timestamps))
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}
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rvs = append(rvs, &tmp)
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}
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return rvs
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}
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type rollupResultCacheMetainfo struct {
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entries []rollupResultCacheMetainfoEntry
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}
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func (mi *rollupResultCacheMetainfo) Marshal(dst []byte) []byte {
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dst = encoding.MarshalUint32(dst, uint32(len(mi.entries)))
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for i := range mi.entries {
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dst = mi.entries[i].Marshal(dst)
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}
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return dst
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}
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func (mi *rollupResultCacheMetainfo) Unmarshal(src []byte) error {
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if len(src) < 4 {
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return fmt.Errorf("cannot unmarshal len(etries) from %d bytes; need at least %d bytes", len(src), 4)
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}
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entriesLen := int(encoding.UnmarshalUint32(src))
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src = src[4:]
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if n := entriesLen - cap(mi.entries); n > 0 {
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mi.entries = append(mi.entries[:cap(mi.entries)], make([]rollupResultCacheMetainfoEntry, n)...)
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}
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mi.entries = mi.entries[:entriesLen]
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for i := 0; i < entriesLen; i++ {
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tail, err := mi.entries[i].Unmarshal(src)
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if err != nil {
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return fmt.Errorf("cannot unmarshal entry #%d: %w", i, err)
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}
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src = tail
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}
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if len(src) > 0 {
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return fmt.Errorf("unexpected non-empty tail left; len(tail)=%d", len(src))
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}
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return nil
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}
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func (mi *rollupResultCacheMetainfo) GetBestKey(start, end int64) rollupResultCacheKey {
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if start > end {
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logger.Panicf("BUG: start cannot exceed end; got %d vs %d", start, end)
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}
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var bestKey rollupResultCacheKey
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bestD := int64(1<<63 - 1)
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for i := range mi.entries {
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e := &mi.entries[i]
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if start < e.start || end <= e.start {
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continue
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}
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d := start - e.start
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if d < bestD {
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bestD = d
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bestKey = e.key
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}
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}
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return bestKey
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}
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func (mi *rollupResultCacheMetainfo) AddKey(key rollupResultCacheKey, start, end int64) {
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if start > end {
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logger.Panicf("BUG: start cannot exceed end; got %d vs %d", start, end)
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}
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mi.entries = append(mi.entries, rollupResultCacheMetainfoEntry{
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start: start,
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end: end,
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key: key,
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})
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if len(mi.entries) > 30 {
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// Remove old entries.
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mi.entries = append(mi.entries[:0], mi.entries[10:]...)
|
|
}
|
|
}
|
|
|
|
func (mi *rollupResultCacheMetainfo) RemoveKey(key rollupResultCacheKey) {
|
|
for i := range mi.entries {
|
|
if mi.entries[i].key == key {
|
|
mi.entries = append(mi.entries[:i], mi.entries[i+1:]...)
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
type rollupResultCacheMetainfoEntry struct {
|
|
start int64
|
|
end int64
|
|
key rollupResultCacheKey
|
|
}
|
|
|
|
func (mie *rollupResultCacheMetainfoEntry) Marshal(dst []byte) []byte {
|
|
dst = encoding.MarshalInt64(dst, mie.start)
|
|
dst = encoding.MarshalInt64(dst, mie.end)
|
|
dst = encoding.MarshalUint64(dst, mie.key.prefix)
|
|
dst = encoding.MarshalUint64(dst, mie.key.suffix)
|
|
return dst
|
|
}
|
|
|
|
func (mie *rollupResultCacheMetainfoEntry) Unmarshal(src []byte) ([]byte, error) {
|
|
if len(src) < 8 {
|
|
return src, fmt.Errorf("cannot unmarshal start from %d bytes; need at least %d bytes", len(src), 8)
|
|
}
|
|
mie.start = encoding.UnmarshalInt64(src)
|
|
src = src[8:]
|
|
|
|
if len(src) < 8 {
|
|
return src, fmt.Errorf("cannot unmarshal end from %d bytes; need at least %d bytes", len(src), 8)
|
|
}
|
|
mie.end = encoding.UnmarshalInt64(src)
|
|
src = src[8:]
|
|
|
|
if len(src) < 8 {
|
|
return src, fmt.Errorf("cannot unmarshal key prefix from %d bytes; need at least %d bytes", len(src), 8)
|
|
}
|
|
mie.key.prefix = encoding.UnmarshalUint64(src)
|
|
src = src[8:]
|
|
|
|
if len(src) < 8 {
|
|
return src, fmt.Errorf("cannot unmarshal key suffix from %d bytes; need at least %d bytes", len(src), 8)
|
|
}
|
|
mie.key.suffix = encoding.UnmarshalUint64(src)
|
|
src = src[8:]
|
|
|
|
return src, nil
|
|
}
|
|
|
|
// rollupResultCacheKey must be globally unique across vmselect nodes,
|
|
// so it has prefix and suffix.
|
|
type rollupResultCacheKey struct {
|
|
prefix uint64
|
|
suffix uint64
|
|
}
|
|
|
|
func (k *rollupResultCacheKey) Marshal(dst []byte) []byte {
|
|
dst = append(dst, rollupResultCacheVersion)
|
|
dst = encoding.MarshalUint64(dst, k.prefix)
|
|
dst = encoding.MarshalUint64(dst, k.suffix)
|
|
return dst
|
|
}
|