VictoriaMetrics/app/vmselect/promql/transform.go
Ze'ev Klapow 79e1c6a6fc
fix le buckets when adjacent vmrange is empty (#4021)
There is a bug here where if you have a single bucket like:

foo{vmrange="4.084e+02...4.642e+02"} 2 123

The expected output is three le encoded buckets like:

foo{le="4.084e+02"} 0 123
foo{le="4.642e+02"} 2 123
foo{le="+Inf"} 2 123

This correctly encodes the start and end of the vmrange.
If however, the input contains the previous bucket, and that bucket is
empty then you only get the end le and +Inf out currently, i.e:

foo{vmrange="7.743e+05...8.799e+05"} 5 123
foo{vmrange="6.813e+05...7.743e+05"} 0 123

results in:

foo{le="8.799e+05"} 5 123
foo{le="+Inf"} 5 123

This causes issues when you go to compute a quantile because this means
that the assumed lower bound of the buckets is 0 and this we interpolate
between 0->end rather than the vmrange start->end as expected.
2023-03-27 17:54:19 -07:00

2786 lines
66 KiB
Go

package promql
import (
"bytes"
"fmt"
"math"
"math/rand"
"regexp"
"sort"
"strconv"
"strings"
"time"
"github.com/VictoriaMetrics/VictoriaMetrics/app/vmselect/searchutils"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/decimal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
"github.com/VictoriaMetrics/metricsql"
)
var transformFuncs = map[string]transformFunc{
"": transformUnion, // empty func is a synonym to union
"abs": newTransformFuncOneArg(transformAbs),
"absent": transformAbsent,
"acos": newTransformFuncOneArg(transformAcos),
"acosh": newTransformFuncOneArg(transformAcosh),
"asin": newTransformFuncOneArg(transformAsin),
"asinh": newTransformFuncOneArg(transformAsinh),
"atan": newTransformFuncOneArg(transformAtan),
"atanh": newTransformFuncOneArg(transformAtanh),
"bitmap_and": newTransformBitmap(bitmapAnd),
"bitmap_or": newTransformBitmap(bitmapOr),
"bitmap_xor": newTransformBitmap(bitmapXor),
"buckets_limit": transformBucketsLimit,
"ceil": newTransformFuncOneArg(transformCeil),
"clamp": transformClamp,
"clamp_max": transformClampMax,
"clamp_min": transformClampMin,
"cos": newTransformFuncOneArg(transformCos),
"cosh": newTransformFuncOneArg(transformCosh),
"day_of_month": newTransformFuncDateTime(transformDayOfMonth),
"day_of_week": newTransformFuncDateTime(transformDayOfWeek),
"days_in_month": newTransformFuncDateTime(transformDaysInMonth),
"deg": newTransformFuncOneArg(transformDeg),
"drop_common_labels": transformDropCommonLabels,
"end": newTransformFuncZeroArgs(transformEnd),
"exp": newTransformFuncOneArg(transformExp),
"floor": newTransformFuncOneArg(transformFloor),
"histogram_avg": transformHistogramAvg,
"histogram_quantile": transformHistogramQuantile,
"histogram_quantiles": transformHistogramQuantiles,
"histogram_share": transformHistogramShare,
"histogram_stddev": transformHistogramStddev,
"histogram_stdvar": transformHistogramStdvar,
"hour": newTransformFuncDateTime(transformHour),
"interpolate": transformInterpolate,
"keep_last_value": transformKeepLastValue,
"keep_next_value": transformKeepNextValue,
"label_copy": transformLabelCopy,
"label_del": transformLabelDel,
"label_graphite_group": transformLabelGraphiteGroup,
"label_join": transformLabelJoin,
"label_keep": transformLabelKeep,
"label_lowercase": transformLabelLowercase,
"label_map": transformLabelMap,
"label_match": transformLabelMatch,
"label_mismatch": transformLabelMismatch,
"label_move": transformLabelMove,
"label_replace": transformLabelReplace,
"label_set": transformLabelSet,
"label_transform": transformLabelTransform,
"label_uppercase": transformLabelUppercase,
"label_value": transformLabelValue,
"limit_offset": transformLimitOffset,
"ln": newTransformFuncOneArg(transformLn),
"log2": newTransformFuncOneArg(transformLog2),
"log10": newTransformFuncOneArg(transformLog10),
"minute": newTransformFuncDateTime(transformMinute),
"month": newTransformFuncDateTime(transformMonth),
"now": transformNow,
"pi": transformPi,
"prometheus_buckets": transformPrometheusBuckets,
"rad": newTransformFuncOneArg(transformRad),
"rand": newTransformRand(newRandFloat64),
"rand_exponential": newTransformRand(newRandExpFloat64),
"rand_normal": newTransformRand(newRandNormFloat64),
"range_avg": newTransformFuncRange(runningAvg),
"range_first": transformRangeFirst,
"range_last": transformRangeLast,
"range_linear_regression": transformRangeLinearRegression,
"range_mad": transformRangeMAD,
"range_max": newTransformFuncRange(runningMax),
"range_min": newTransformFuncRange(runningMin),
"range_normalize": transformRangeNormalize,
"range_quantile": transformRangeQuantile,
"range_stddev": transformRangeStddev,
"range_stdvar": transformRangeStdvar,
"range_sum": newTransformFuncRange(runningSum),
"range_trim_outliers": transformRangeTrimOutliers,
"range_trim_spikes": transformRangeTrimSpikes,
"range_trim_zscore": transformRangeTrimZscore,
"range_zscore": transformRangeZscore,
"remove_resets": transformRemoveResets,
"round": transformRound,
"running_avg": newTransformFuncRunning(runningAvg),
"running_max": newTransformFuncRunning(runningMax),
"running_min": newTransformFuncRunning(runningMin),
"running_sum": newTransformFuncRunning(runningSum),
"scalar": transformScalar,
"sgn": transformSgn,
"sin": newTransformFuncOneArg(transformSin),
"sinh": newTransformFuncOneArg(transformSinh),
"smooth_exponential": transformSmoothExponential,
"sort": newTransformFuncSort(false),
"sort_by_label": newTransformFuncSortByLabel(false),
"sort_by_label_desc": newTransformFuncSortByLabel(true),
"sort_by_label_numeric": newTransformFuncNumericSort(false),
"sort_by_label_numeric_desc": newTransformFuncNumericSort(true),
"sort_desc": newTransformFuncSort(true),
"sqrt": newTransformFuncOneArg(transformSqrt),
"start": newTransformFuncZeroArgs(transformStart),
"step": newTransformFuncZeroArgs(transformStep),
"tan": newTransformFuncOneArg(transformTan),
"tanh": newTransformFuncOneArg(transformTanh),
"time": transformTime,
// "timestamp" has been moved to rollup funcs. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/415
"timezone_offset": transformTimezoneOffset,
"union": transformUnion,
"vector": transformVector,
"year": newTransformFuncDateTime(transformYear),
}
// These functions don't change physical meaning of input time series,
// so they don't drop metric name
var transformFuncsKeepMetricName = map[string]bool{
"ceil": true,
"clamp": true,
"clamp_max": true,
"clamp_min": true,
"floor": true,
"interpolate": true,
"keep_last_value": true,
"keep_next_value": true,
"range_avg": true,
"range_first": true,
"range_last": true,
"range_linear_regression": true,
"range_max": true,
"range_min": true,
"range_normalize": true,
"range_quantile": true,
"range_stdvar": true,
"range_sddev": true,
"round": true,
"running_avg": true,
"running_max": true,
"running_min": true,
"smooth_exponential": true,
}
func getTransformFunc(s string) transformFunc {
s = strings.ToLower(s)
return transformFuncs[s]
}
type transformFuncArg struct {
ec *EvalConfig
fe *metricsql.FuncExpr
args [][]*timeseries
}
type transformFunc func(tfa *transformFuncArg) ([]*timeseries, error)
func newTransformFuncOneArg(tf func(v float64) float64) transformFunc {
tfe := func(values []float64) {
for i, v := range values {
values[i] = tf(v)
}
}
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
return doTransformValues(args[0], tfe, tfa.fe)
}
}
func doTransformValues(arg []*timeseries, tf func(values []float64), fe *metricsql.FuncExpr) ([]*timeseries, error) {
name := strings.ToLower(fe.Name)
keepMetricNames := fe.KeepMetricNames
if transformFuncsKeepMetricName[name] {
keepMetricNames = true
}
for _, ts := range arg {
if !keepMetricNames {
ts.MetricName.ResetMetricGroup()
}
tf(ts.Values)
}
return arg, nil
}
func transformAbs(v float64) float64 {
return math.Abs(v)
}
func transformAbsent(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
tss := args[0]
rvs := getAbsentTimeseries(tfa.ec, tfa.fe.Args[0])
if len(tss) == 0 {
return rvs, nil
}
for i := range tss[0].Values {
isAbsent := true
for _, ts := range tss {
if !math.IsNaN(ts.Values[i]) {
isAbsent = false
break
}
}
if !isAbsent {
rvs[0].Values[i] = nan
}
}
return rvs, nil
}
func getAbsentTimeseries(ec *EvalConfig, arg metricsql.Expr) []*timeseries {
// Copy tags from arg
rvs := evalNumber(ec, 1)
rv := rvs[0]
me, ok := arg.(*metricsql.MetricExpr)
if !ok {
return rvs
}
tfs := searchutils.ToTagFilters(me.LabelFilters)
for i := range tfs {
tf := &tfs[i]
if len(tf.Key) == 0 {
continue
}
if tf.IsRegexp || tf.IsNegative {
continue
}
rv.MetricName.AddTagBytes(tf.Key, tf.Value)
}
return rvs
}
func transformCeil(v float64) float64 {
return math.Ceil(v)
}
func transformClamp(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 3); err != nil {
return nil, err
}
mins, err := getScalar(args[1], 1)
if err != nil {
return nil, err
}
maxs, err := getScalar(args[2], 2)
if err != nil {
return nil, err
}
tf := func(values []float64) {
for i, v := range values {
if v > maxs[i] {
values[i] = maxs[i]
} else if v < mins[i] {
values[i] = mins[i]
}
}
}
return doTransformValues(args[0], tf, tfa.fe)
}
func transformClampMax(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
maxs, err := getScalar(args[1], 1)
if err != nil {
return nil, err
}
tf := func(values []float64) {
for i, v := range values {
if v > maxs[i] {
values[i] = maxs[i]
}
}
}
return doTransformValues(args[0], tf, tfa.fe)
}
func transformClampMin(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
mins, err := getScalar(args[1], 1)
if err != nil {
return nil, err
}
tf := func(values []float64) {
for i, v := range values {
if v < mins[i] {
values[i] = mins[i]
}
}
}
return doTransformValues(args[0], tf, tfa.fe)
}
func newTransformFuncDateTime(f func(t time.Time) int) transformFunc {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) > 1 {
return nil, fmt.Errorf(`too many args; got %d; want up to %d`, len(args), 1)
}
var arg []*timeseries
if len(args) == 0 {
arg = evalTime(tfa.ec)
} else {
arg = args[0]
}
tf := func(values []float64) {
for i, v := range values {
if math.IsNaN(v) {
continue
}
t := time.Unix(int64(v), 0).UTC()
values[i] = float64(f(t))
}
}
return doTransformValues(arg, tf, tfa.fe)
}
}
func transformDayOfMonth(t time.Time) int {
return t.Day()
}
func transformDayOfWeek(t time.Time) int {
return int(t.Weekday())
}
func transformDaysInMonth(t time.Time) int {
m := t.Month()
if m == 2 && isLeapYear(uint32(t.Year())) {
return 29
}
return daysInMonth[m]
}
func transformExp(v float64) float64 {
return math.Exp(v)
}
func transformFloor(v float64) float64 {
return math.Floor(v)
}
func transformBucketsLimit(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
limit, err := getIntNumber(args[0], 0)
if err != nil {
return nil, err
}
if limit <= 0 {
return nil, nil
}
if limit < 3 {
// Preserve the first and the last bucket for better accuracy for min and max values.
limit = 3
}
tss := vmrangeBucketsToLE(args[1])
if len(tss) == 0 {
return nil, nil
}
pointsCount := len(tss[0].Values)
// Group timeseries by all MetricGroup+tags excluding `le` tag.
type x struct {
le float64
hits float64
ts *timeseries
}
m := make(map[string][]x)
var b []byte
var mn storage.MetricName
for _, ts := range tss {
leStr := ts.MetricName.GetTagValue("le")
if len(leStr) == 0 {
// Skip time series without `le` tag.
continue
}
le, err := strconv.ParseFloat(string(leStr), 64)
if err != nil {
// Skip time series with invalid `le` tag.
continue
}
mn.CopyFrom(&ts.MetricName)
mn.RemoveTag("le")
b = marshalMetricNameSorted(b[:0], &mn)
k := bytesutil.InternBytes(b)
m[k] = append(m[k], x{
le: le,
ts: ts,
})
}
// Remove buckets with the smallest counters.
rvs := make([]*timeseries, 0, len(tss))
for _, leGroup := range m {
if len(leGroup) <= limit {
// Fast path - the number of buckets doesn't exceed the given limit.
// Keep all the buckets as is.
for _, xx := range leGroup {
rvs = append(rvs, xx.ts)
}
continue
}
// Slow path - remove buckets with the smallest number of hits until their count reaches the limit.
// Calculate per-bucket hits.
sort.Slice(leGroup, func(i, j int) bool {
return leGroup[i].le < leGroup[j].le
})
for n := 0; n < pointsCount; n++ {
prevValue := float64(0)
for i := range leGroup {
xx := &leGroup[i]
value := xx.ts.Values[n]
xx.hits += value - prevValue
prevValue = value
}
}
for len(leGroup) > limit {
// Preserve the first and the last bucket for better accuracy for min and max values
xxMinIdx := 1
minMergeHits := leGroup[1].hits + leGroup[2].hits
for i := range leGroup[1 : len(leGroup)-2] {
mergeHits := leGroup[i+1].hits + leGroup[i+2].hits
if mergeHits < minMergeHits {
xxMinIdx = i + 1
minMergeHits = mergeHits
}
}
leGroup[xxMinIdx+1].hits += leGroup[xxMinIdx].hits
leGroup = append(leGroup[:xxMinIdx], leGroup[xxMinIdx+1:]...)
}
for _, xx := range leGroup {
rvs = append(rvs, xx.ts)
}
}
return rvs, nil
}
func transformPrometheusBuckets(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := vmrangeBucketsToLE(args[0])
return rvs, nil
}
func vmrangeBucketsToLE(tss []*timeseries) []*timeseries {
rvs := make([]*timeseries, 0, len(tss))
// Group timeseries by MetricGroup+tags excluding `vmrange` tag.
type x struct {
startStr string
endStr string
start float64
end float64
ts *timeseries
}
m := make(map[string][]x)
bb := bbPool.Get()
defer bbPool.Put(bb)
for _, ts := range tss {
vmrange := ts.MetricName.GetTagValue("vmrange")
if len(vmrange) == 0 {
if le := ts.MetricName.GetTagValue("le"); len(le) > 0 {
// Keep Prometheus-compatible buckets.
rvs = append(rvs, ts)
}
continue
}
n := strings.Index(bytesutil.ToUnsafeString(vmrange), "...")
if n < 0 {
continue
}
startStr := string(vmrange[:n])
start, err := strconv.ParseFloat(startStr, 64)
if err != nil {
continue
}
endStr := string(vmrange[n+len("..."):])
end, err := strconv.ParseFloat(endStr, 64)
if err != nil {
continue
}
ts.MetricName.RemoveTag("le")
ts.MetricName.RemoveTag("vmrange")
bb.B = marshalMetricNameSorted(bb.B[:0], &ts.MetricName)
k := bytesutil.InternBytes(bb.B)
m[k] = append(m[k], x{
startStr: startStr,
endStr: endStr,
start: start,
end: end,
ts: ts,
})
}
// Convert `vmrange` label in each group of time series to `le` label.
copyTS := func(src *timeseries, leStr string) *timeseries {
var ts timeseries
ts.CopyFromShallowTimestamps(src)
values := ts.Values
for i := range values {
values[i] = 0
}
ts.MetricName.RemoveTag("le")
ts.MetricName.AddTag("le", leStr)
return &ts
}
isZeroTS := func(ts *timeseries) bool {
for _, v := range ts.Values {
if v > 0 {
return false
}
}
return true
}
for _, xss := range m {
sort.Slice(xss, func(i, j int) bool { return xss[i].end < xss[j].end })
xssNew := make([]x, 0, len(xss)+2)
var xsPrev x
hasNonEmpty := false
uniqTs := make(map[string]*timeseries, len(xss))
for _, xs := range xss {
ts := xs.ts
if isZeroTS(ts) {
xsPrev = xs
if uniqTs[xs.endStr] == nil {
uniqTs[xs.endStr] = xs.ts
xssNew = append(xssNew, x{
endStr: xs.endStr,
end: xs.end,
ts: copyTS(ts, xs.endStr),
})
}
continue
}
hasNonEmpty = true
if xs.start != xsPrev.end && uniqTs[xs.startStr] == nil {
uniqTs[xs.startStr] = xs.ts
xssNew = append(xssNew, x{
endStr: xs.startStr,
end: xs.start,
ts: copyTS(ts, xs.startStr),
})
}
ts.MetricName.AddTag("le", xs.endStr)
prevTs := uniqTs[xs.endStr]
if prevTs != nil {
// the end of the current bucket is not unique, need to merge it with the existing bucket.
_ = mergeNonOverlappingTimeseries(prevTs, xs.ts)
} else {
xssNew = append(xssNew, xs)
uniqTs[xs.endStr] = xs.ts
}
xsPrev = xs
}
if !hasNonEmpty {
xssNew = []x{}
continue
}
if !math.IsInf(xsPrev.end, 1) && !isZeroTS(xsPrev.ts) {
xssNew = append(xssNew, x{
endStr: "+Inf",
end: math.Inf(1),
ts: copyTS(xsPrev.ts, "+Inf"),
})
}
xss = xssNew
if len(xss) == 0 {
continue
}
for i := range xss[0].ts.Values {
count := float64(0)
for _, xs := range xss {
ts := xs.ts
v := ts.Values[i]
if !math.IsNaN(v) && v > 0 {
count += v
}
ts.Values[i] = count
}
}
for _, xs := range xss {
rvs = append(rvs, xs.ts)
}
}
return rvs
}
func transformHistogramShare(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 2 || len(args) > 3 {
return nil, fmt.Errorf("unexpected number of args; got %d; want 2...3", len(args))
}
les, err := getScalar(args[0], 0)
if err != nil {
return nil, fmt.Errorf("cannot parse le: %w", err)
}
// Convert buckets with `vmrange` labels to buckets with `le` labels.
tss := vmrangeBucketsToLE(args[1])
// Parse boundsLabel. See https://github.com/prometheus/prometheus/issues/5706 for details.
var boundsLabel string
if len(args) > 2 {
s, err := getString(args[2], 2)
if err != nil {
return nil, fmt.Errorf("cannot parse boundsLabel (arg #3): %w", err)
}
boundsLabel = s
}
// Group metrics by all tags excluding "le"
m := groupLeTimeseries(tss)
// Calculate share for les
share := func(i int, les []float64, xss []leTimeseries) (q, lower, upper float64) {
leReq := les[i]
if math.IsNaN(leReq) || len(xss) == 0 {
return nan, nan, nan
}
fixBrokenBuckets(i, xss)
if leReq < 0 {
return 0, 0, 0
}
if math.IsInf(leReq, 1) {
return 1, 1, 1
}
var vPrev, lePrev float64
for _, xs := range xss {
v := xs.ts.Values[i]
le := xs.le
if leReq >= le {
vPrev = v
lePrev = le
continue
}
// precondition: lePrev <= leReq < le
vLast := xss[len(xss)-1].ts.Values[i]
lower = vPrev / vLast
if math.IsInf(le, 1) {
return lower, lower, 1
}
if lePrev == leReq {
return lower, lower, lower
}
upper = v / vLast
q = lower + (v-vPrev)/vLast*(leReq-lePrev)/(le-lePrev)
return q, lower, upper
}
// precondition: leReq > leLast
return 1, 1, 1
}
rvs := make([]*timeseries, 0, len(m))
for _, xss := range m {
sort.Slice(xss, func(i, j int) bool {
return xss[i].le < xss[j].le
})
xss = mergeSameLE(xss)
dst := xss[0].ts
var tsLower, tsUpper *timeseries
if len(boundsLabel) > 0 {
tsLower = &timeseries{}
tsLower.CopyFromShallowTimestamps(dst)
tsLower.MetricName.RemoveTag(boundsLabel)
tsLower.MetricName.AddTag(boundsLabel, "lower")
tsUpper = &timeseries{}
tsUpper.CopyFromShallowTimestamps(dst)
tsUpper.MetricName.RemoveTag(boundsLabel)
tsUpper.MetricName.AddTag(boundsLabel, "upper")
}
for i := range dst.Values {
q, lower, upper := share(i, les, xss)
dst.Values[i] = q
if len(boundsLabel) > 0 {
tsLower.Values[i] = lower
tsUpper.Values[i] = upper
}
}
rvs = append(rvs, dst)
if len(boundsLabel) > 0 {
rvs = append(rvs, tsLower)
rvs = append(rvs, tsUpper)
}
}
return rvs, nil
}
func transformHistogramAvg(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
tss := vmrangeBucketsToLE(args[0])
m := groupLeTimeseries(tss)
rvs := make([]*timeseries, 0, len(m))
for _, xss := range m {
sort.Slice(xss, func(i, j int) bool {
return xss[i].le < xss[j].le
})
dst := xss[0].ts
for i := range dst.Values {
dst.Values[i] = avgForLeTimeseries(i, xss)
}
rvs = append(rvs, dst)
}
return rvs, nil
}
func transformHistogramStddev(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
tss := vmrangeBucketsToLE(args[0])
m := groupLeTimeseries(tss)
rvs := make([]*timeseries, 0, len(m))
for _, xss := range m {
sort.Slice(xss, func(i, j int) bool {
return xss[i].le < xss[j].le
})
dst := xss[0].ts
for i := range dst.Values {
v := stdvarForLeTimeseries(i, xss)
dst.Values[i] = math.Sqrt(v)
}
rvs = append(rvs, dst)
}
return rvs, nil
}
func transformHistogramStdvar(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
tss := vmrangeBucketsToLE(args[0])
m := groupLeTimeseries(tss)
rvs := make([]*timeseries, 0, len(m))
for _, xss := range m {
sort.Slice(xss, func(i, j int) bool {
return xss[i].le < xss[j].le
})
dst := xss[0].ts
for i := range dst.Values {
dst.Values[i] = stdvarForLeTimeseries(i, xss)
}
rvs = append(rvs, dst)
}
return rvs, nil
}
func avgForLeTimeseries(i int, xss []leTimeseries) float64 {
lePrev := float64(0)
vPrev := float64(0)
sum := float64(0)
weightTotal := float64(0)
for _, xs := range xss {
if math.IsInf(xs.le, 0) {
continue
}
le := xs.le
n := (le + lePrev) / 2
v := xs.ts.Values[i]
weight := v - vPrev
sum += n * weight
weightTotal += weight
lePrev = le
vPrev = v
}
if weightTotal == 0 {
return nan
}
return sum / weightTotal
}
func stdvarForLeTimeseries(i int, xss []leTimeseries) float64 {
lePrev := float64(0)
vPrev := float64(0)
sum := float64(0)
sum2 := float64(0)
weightTotal := float64(0)
for _, xs := range xss {
if math.IsInf(xs.le, 0) {
continue
}
le := xs.le
n := (le + lePrev) / 2
v := xs.ts.Values[i]
weight := v - vPrev
sum += n * weight
sum2 += n * n * weight
weightTotal += weight
lePrev = le
vPrev = v
}
if weightTotal == 0 {
return nan
}
avg := sum / weightTotal
avg2 := sum2 / weightTotal
stdvar := avg2 - avg*avg
if stdvar < 0 {
// Correct possible calculation error.
stdvar = 0
}
return stdvar
}
func transformHistogramQuantiles(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 3 {
return nil, fmt.Errorf("unexpected number of args: %d; expecting at least 3 args", len(args))
}
dstLabel, err := getString(args[0], 0)
if err != nil {
return nil, fmt.Errorf("cannot obtain dstLabel: %w", err)
}
phiArgs := args[1 : len(args)-1]
tssOrig := args[len(args)-1]
// Calculate quantile individually per each phi.
var rvs []*timeseries
for i, phiArg := range phiArgs {
phis, err := getScalar(phiArg, i)
if err != nil {
return nil, fmt.Errorf("cannot parse phi: %w", err)
}
phiStr := fmt.Sprintf("%g", phis[0])
tss := copyTimeseries(tssOrig)
tfaTmp := &transformFuncArg{
ec: tfa.ec,
fe: tfa.fe,
args: [][]*timeseries{
phiArg,
tss,
},
}
tssTmp, err := transformHistogramQuantile(tfaTmp)
if err != nil {
return nil, fmt.Errorf("cannot calculate quantile %s: %w", phiStr, err)
}
for _, ts := range tssTmp {
ts.MetricName.RemoveTag(dstLabel)
ts.MetricName.AddTag(dstLabel, phiStr)
}
rvs = append(rvs, tssTmp...)
}
return rvs, nil
}
func transformHistogramQuantile(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 2 || len(args) > 3 {
return nil, fmt.Errorf("unexpected number of args; got %d; want 2...3", len(args))
}
phis, err := getScalar(args[0], 0)
if err != nil {
return nil, fmt.Errorf("cannot parse phi: %w", err)
}
// Convert buckets with `vmrange` labels to buckets with `le` labels.
tss := vmrangeBucketsToLE(args[1])
// Parse boundsLabel. See https://github.com/prometheus/prometheus/issues/5706 for details.
var boundsLabel string
if len(args) > 2 {
s, err := getString(args[2], 2)
if err != nil {
return nil, fmt.Errorf("cannot parse boundsLabel (arg #3): %w", err)
}
boundsLabel = s
}
// Group metrics by all tags excluding "le"
m := groupLeTimeseries(tss)
// Calculate quantile for each group in m
lastNonInf := func(i int, xss []leTimeseries) float64 {
for len(xss) > 0 {
xsLast := xss[len(xss)-1]
if !math.IsInf(xsLast.le, 0) {
return xsLast.le
}
xss = xss[:len(xss)-1]
}
return nan
}
quantile := func(i int, phis []float64, xss []leTimeseries) (q, lower, upper float64) {
phi := phis[i]
if math.IsNaN(phi) {
return nan, nan, nan
}
fixBrokenBuckets(i, xss)
vLast := float64(0)
if len(xss) > 0 {
vLast = xss[len(xss)-1].ts.Values[i]
}
if vLast == 0 {
return nan, nan, nan
}
if phi < 0 {
return -inf, -inf, xss[0].ts.Values[i]
}
if phi > 1 {
return inf, vLast, inf
}
vReq := vLast * phi
vPrev := float64(0)
lePrev := float64(0)
for _, xs := range xss {
v := xs.ts.Values[i]
le := xs.le
if v <= 0 {
// Skip zero buckets.
lePrev = le
continue
}
if v < vReq {
vPrev = v
lePrev = le
continue
}
if math.IsInf(le, 0) {
break
}
if v == vPrev {
return lePrev, lePrev, v
}
vv := lePrev + (le-lePrev)*(vReq-vPrev)/(v-vPrev)
return vv, lePrev, le
}
vv := lastNonInf(i, xss)
return vv, vv, inf
}
rvs := make([]*timeseries, 0, len(m))
for _, xss := range m {
sort.Slice(xss, func(i, j int) bool {
return xss[i].le < xss[j].le
})
xss = mergeSameLE(xss)
dst := xss[0].ts
var tsLower, tsUpper *timeseries
if len(boundsLabel) > 0 {
tsLower = &timeseries{}
tsLower.CopyFromShallowTimestamps(dst)
tsLower.MetricName.RemoveTag(boundsLabel)
tsLower.MetricName.AddTag(boundsLabel, "lower")
tsUpper = &timeseries{}
tsUpper.CopyFromShallowTimestamps(dst)
tsUpper.MetricName.RemoveTag(boundsLabel)
tsUpper.MetricName.AddTag(boundsLabel, "upper")
}
for i := range dst.Values {
v, lower, upper := quantile(i, phis, xss)
dst.Values[i] = v
if len(boundsLabel) > 0 {
tsLower.Values[i] = lower
tsUpper.Values[i] = upper
}
}
rvs = append(rvs, dst)
if len(boundsLabel) > 0 {
rvs = append(rvs, tsLower)
rvs = append(rvs, tsUpper)
}
}
return rvs, nil
}
type leTimeseries struct {
le float64
ts *timeseries
}
func groupLeTimeseries(tss []*timeseries) map[string][]leTimeseries {
m := make(map[string][]leTimeseries)
bb := bbPool.Get()
for _, ts := range tss {
tagValue := ts.MetricName.GetTagValue("le")
if len(tagValue) == 0 {
continue
}
le, err := strconv.ParseFloat(bytesutil.ToUnsafeString(tagValue), 64)
if err != nil {
continue
}
ts.MetricName.ResetMetricGroup()
ts.MetricName.RemoveTag("le")
bb.B = marshalMetricTagsSorted(bb.B[:0], &ts.MetricName)
k := bytesutil.InternBytes(bb.B)
m[k] = append(m[k], leTimeseries{
le: le,
ts: ts,
})
}
bbPool.Put(bb)
return m
}
func fixBrokenBuckets(i int, xss []leTimeseries) {
// Buckets are already sorted by le, so their values must be in ascending order,
// since the next bucket includes all the previous buckets.
// If the next bucket has lower value than the current bucket,
// then the current bucket must be substituted with the next bucket value.
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2819
if len(xss) < 2 {
return
}
// Fill NaN in upper buckets with the first non-NaN value found in lower buckets.
for j := len(xss) - 1; j >= 0; j-- {
v := xss[j].ts.Values[i]
if !math.IsNaN(v) {
j++
for j < len(xss) {
xss[j].ts.Values[i] = v
j++
}
break
}
}
// Substitute lower bucket values with upper values if the lower values are NaN
// or are bigger than the upper bucket values.
vNext := xss[len(xss)-1].ts.Values[i]
for j := len(xss) - 2; j >= 0; j-- {
v := xss[j].ts.Values[i]
if math.IsNaN(v) || v > vNext {
xss[j].ts.Values[i] = vNext
} else {
vNext = v
}
}
}
func mergeSameLE(xss []leTimeseries) []leTimeseries {
// Merge buckets with identical le values.
// See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3225
xsDst := xss[0]
dst := xss[:1]
for j := 1; j < len(xss); j++ {
xs := xss[j]
if xs.le != xsDst.le {
dst = append(dst, xs)
xsDst = xs
continue
}
dstValues := xsDst.ts.Values
for k, v := range xs.ts.Values {
dstValues[k] += v
}
}
return dst
}
func transformHour(t time.Time) int {
return t.Hour()
}
func runningSum(a, b float64, idx int) float64 {
return a + b
}
func runningMax(a, b float64, idx int) float64 {
if a > b {
return a
}
return b
}
func runningMin(a, b float64, idx int) float64 {
if a < b {
return a
}
return b
}
func runningAvg(a, b float64, idx int) float64 {
// See `Rapid calculation methods` at https://en.wikipedia.org/wiki/Standard_deviation
return a + (b-a)/float64(idx+1)
}
func skipLeadingNaNs(values []float64) []float64 {
i := 0
for i < len(values) && math.IsNaN(values[i]) {
i++
}
return values[i:]
}
func skipTrailingNaNs(values []float64) []float64 {
i := len(values) - 1
for i >= 0 && math.IsNaN(values[i]) {
i--
}
return values[:i+1]
}
func transformKeepLastValue(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := ts.Values
if len(values) == 0 {
continue
}
lastValue := values[0]
for i, v := range values {
if !math.IsNaN(v) {
lastValue = v
continue
}
values[i] = lastValue
}
}
return rvs, nil
}
func transformKeepNextValue(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := ts.Values
if len(values) == 0 {
continue
}
nextValue := values[len(values)-1]
for i := len(values) - 1; i >= 0; i-- {
v := values[i]
if !math.IsNaN(v) {
nextValue = v
continue
}
values[i] = nextValue
}
}
return rvs, nil
}
func transformInterpolate(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := skipLeadingNaNs(ts.Values)
values = skipTrailingNaNs(values)
if len(values) == 0 {
continue
}
prevValue := nan
var nextValue float64
for i := 0; i < len(values); i++ {
if !math.IsNaN(values[i]) {
continue
}
if i > 0 {
prevValue = values[i-1]
}
j := i + 1
for j < len(values) {
if !math.IsNaN(values[j]) {
break
}
j++
}
if j >= len(values) {
nextValue = prevValue
} else {
nextValue = values[j]
}
if math.IsNaN(prevValue) {
prevValue = nextValue
}
delta := (nextValue - prevValue) / float64(j-i+1)
for i < j {
prevValue += delta
values[i] = prevValue
i++
}
}
}
return rvs, nil
}
func newTransformFuncRunning(rf func(a, b float64, idx int) float64) transformFunc {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
ts.MetricName.ResetMetricGroup()
values := skipLeadingNaNs(ts.Values)
if len(values) == 0 {
continue
}
prevValue := values[0]
values = values[1:]
for i, v := range values {
if !math.IsNaN(v) {
prevValue = rf(prevValue, v, i+1)
}
values[i] = prevValue
}
}
return rvs, nil
}
}
func newTransformFuncRange(rf func(a, b float64, idx int) float64) transformFunc {
tfr := newTransformFuncRunning(rf)
return func(tfa *transformFuncArg) ([]*timeseries, error) {
rvs, err := tfr(tfa)
if err != nil {
return nil, err
}
setLastValues(rvs)
return rvs, nil
}
}
func transformRangeNormalize(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
var rvs []*timeseries
for _, tss := range args {
for _, ts := range tss {
values := ts.Values
vMin := inf
vMax := -inf
for _, v := range values {
if math.IsNaN(v) {
continue
}
if v < vMin {
vMin = v
}
if v > vMax {
vMax = v
}
}
d := vMax - vMin
if math.IsInf(d, 0) {
continue
}
for i, v := range values {
values[i] = (v - vMin) / d
}
rvs = append(rvs, ts)
}
}
return rvs, nil
}
func transformRangeTrimZscore(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
zs, err := getScalar(args[0], 0)
if err != nil {
return nil, err
}
z := float64(0)
if len(zs) > 0 {
z = math.Abs(zs[0])
}
// Trim samples with z-score above z.
rvs := args[1]
for _, ts := range rvs {
values := ts.Values
qStddev := stddev(values)
avg := mean(values)
for i, v := range values {
zCurr := math.Abs(v-avg) / qStddev
if zCurr > z {
values[i] = nan
}
}
}
return rvs, nil
}
func transformRangeZscore(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := ts.Values
qStddev := stddev(values)
avg := mean(values)
for i, v := range values {
values[i] = (v - avg) / qStddev
}
}
return rvs, nil
}
func mean(values []float64) float64 {
var sum float64
var n int
for _, v := range values {
if !math.IsNaN(v) {
sum += v
n++
}
}
return sum / float64(n)
}
func transformRangeTrimOutliers(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
ks, err := getScalar(args[0], 0)
if err != nil {
return nil, err
}
k := float64(0)
if len(ks) > 0 {
k = ks[0]
}
// Trim samples satisfying the `abs(v - range_median(q)) > k*range_mad(q)`
rvs := args[1]
for _, ts := range rvs {
values := ts.Values
dMax := k * mad(values)
qMedian := quantile(0.5, values)
for i, v := range values {
if math.Abs(v-qMedian) > dMax {
values[i] = nan
}
}
}
return rvs, nil
}
func transformRangeTrimSpikes(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
phis, err := getScalar(args[0], 0)
if err != nil {
return nil, err
}
phi := float64(0)
if len(phis) > 0 {
phi = phis[0]
}
// Trim 100% * (phi / 2) samples with the lowest / highest values per each time series
phi /= 2
phiUpper := 1 - phi
phiLower := phi
rvs := args[1]
a := getFloat64s()
values := a.A[:0]
for _, ts := range rvs {
values := values[:0]
originValues := ts.Values
for _, v := range originValues {
if math.IsNaN(v) {
continue
}
values = append(values, v)
}
sort.Float64s(values)
vMax := quantileSorted(phiUpper, values)
vMin := quantileSorted(phiLower, values)
for i, v := range originValues {
if math.IsNaN(v) {
continue
}
if v > vMax {
originValues[i] = nan
} else if v < vMin {
originValues[i] = nan
}
}
}
a.A = values
putFloat64s(a)
return rvs, nil
}
func transformRangeLinearRegression(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := ts.Values
timestamps := ts.Timestamps
if len(timestamps) == 0 {
continue
}
interceptTimestamp := timestamps[0]
v, k := linearRegression(values, timestamps, interceptTimestamp)
for i, t := range timestamps {
values[i] = v + k*float64(t-interceptTimestamp)/1e3
}
}
return rvs, nil
}
func transformRangeMAD(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := ts.Values
v := mad(values)
for i := range values {
values[i] = v
}
}
return rvs, nil
}
func transformRangeStddev(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := ts.Values
v := stddev(values)
for i := range values {
values[i] = v
}
}
return rvs, nil
}
func transformRangeStdvar(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := ts.Values
v := stdvar(values)
for i := range values {
values[i] = v
}
}
return rvs, nil
}
func transformRangeQuantile(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
phis, err := getScalar(args[0], 0)
if err != nil {
return nil, err
}
phi := float64(0)
if len(phis) > 0 {
phi = phis[0]
}
rvs := args[1]
a := getFloat64s()
values := a.A[:0]
for _, ts := range rvs {
lastIdx := -1
originValues := ts.Values
values = values[:0]
for i, v := range originValues {
if math.IsNaN(v) {
continue
}
values = append(values, v)
lastIdx = i
}
if lastIdx >= 0 {
sort.Float64s(values)
originValues[lastIdx] = quantileSorted(phi, values)
}
}
a.A = values
putFloat64s(a)
setLastValues(rvs)
return rvs, nil
}
func transformRangeFirst(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := skipLeadingNaNs(ts.Values)
if len(values) == 0 {
continue
}
vFirst := values[0]
for i, v := range values {
if math.IsNaN(v) {
continue
}
values[i] = vFirst
}
}
return rvs, nil
}
func transformRangeLast(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
setLastValues(rvs)
return rvs, nil
}
func setLastValues(tss []*timeseries) {
for _, ts := range tss {
values := skipTrailingNaNs(ts.Values)
if len(values) == 0 {
continue
}
vLast := values[len(values)-1]
for i, v := range values {
if math.IsNaN(v) {
continue
}
values[i] = vLast
}
}
}
func transformSmoothExponential(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
sfs, err := getScalar(args[1], 1)
if err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
values := skipLeadingNaNs(ts.Values)
for i, v := range values {
if !math.IsInf(v, 0) {
values = values[i:]
break
}
}
if len(values) == 0 {
continue
}
avg := values[0]
values = values[1:]
sfsX := sfs[len(ts.Values)-len(values):]
for i, v := range values {
if math.IsNaN(v) {
continue
}
if math.IsInf(v, 0) {
values[i] = avg
continue
}
sf := sfsX[i]
if math.IsNaN(sf) {
sf = 1
}
if sf < 0 {
sf = 0
}
if sf > 1 {
sf = 1
}
avg = avg*(1-sf) + v*sf
values[i] = avg
}
}
return rvs, nil
}
func transformRemoveResets(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
removeCounterResetsMaybeNaNs(ts.Values)
}
return rvs, nil
}
func transformUnion(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 1 {
return evalNumber(tfa.ec, nan), nil
}
rvs := make([]*timeseries, 0, len(args[0]))
m := make(map[string]bool, len(args[0]))
bb := bbPool.Get()
for _, arg := range args {
for _, ts := range arg {
bb.B = marshalMetricNameSorted(bb.B[:0], &ts.MetricName)
k := bytesutil.InternBytes(bb.B)
if m[k] {
continue
}
m[k] = true
rvs = append(rvs, ts)
}
}
bbPool.Put(bb)
return rvs, nil
}
func transformLabelKeep(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 1 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 1)
}
var keepLabels []string
for i := 1; i < len(args); i++ {
keepLabel, err := getString(args[i], i)
if err != nil {
return nil, err
}
keepLabels = append(keepLabels, keepLabel)
}
rvs := args[0]
for _, ts := range rvs {
ts.MetricName.RemoveTagsOn(keepLabels)
}
return rvs, nil
}
func transformLabelDel(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 1 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 1)
}
var delLabels []string
for i := 1; i < len(args); i++ {
delLabel, err := getString(args[i], i)
if err != nil {
return nil, err
}
delLabels = append(delLabels, delLabel)
}
rvs := args[0]
for _, ts := range rvs {
ts.MetricName.RemoveTagsIgnoring(delLabels)
}
return rvs, nil
}
func transformLabelSet(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 1 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 1)
}
dstLabels, dstValues, err := getStringPairs(args[1:])
if err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
mn := &ts.MetricName
for i, dstLabel := range dstLabels {
value := dstValues[i]
dstValue := getDstValue(mn, dstLabel)
*dstValue = append((*dstValue)[:0], value...)
if len(value) == 0 {
mn.RemoveTag(dstLabel)
}
}
}
return rvs, nil
}
func transformLabelUppercase(tfa *transformFuncArg) ([]*timeseries, error) {
return transformLabelValueFunc(tfa, strings.ToUpper)
}
func transformLabelLowercase(tfa *transformFuncArg) ([]*timeseries, error) {
return transformLabelValueFunc(tfa, strings.ToLower)
}
func transformLabelValueFunc(tfa *transformFuncArg, f func(string) string) ([]*timeseries, error) {
args := tfa.args
if len(args) < 2 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 2)
}
labels := make([]string, 0, len(args)-1)
for i := 1; i < len(args); i++ {
label, err := getString(args[i], i)
if err != nil {
return nil, err
}
labels = append(labels, label)
}
rvs := args[0]
for _, ts := range rvs {
mn := &ts.MetricName
for _, label := range labels {
dstValue := getDstValue(mn, label)
*dstValue = append((*dstValue)[:0], f(string(*dstValue))...)
if len(*dstValue) == 0 {
mn.RemoveTag(label)
}
}
}
return rvs, nil
}
func transformLabelMap(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 2 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 2)
}
label, err := getString(args[1], 1)
if err != nil {
return nil, fmt.Errorf("cannot read label name: %w", err)
}
srcValues, dstValues, err := getStringPairs(args[2:])
if err != nil {
return nil, err
}
m := make(map[string]string, len(srcValues))
for i, srcValue := range srcValues {
m[srcValue] = dstValues[i]
}
rvs := args[0]
for _, ts := range rvs {
mn := &ts.MetricName
dstValue := getDstValue(mn, label)
value, ok := m[string(*dstValue)]
if ok {
*dstValue = append((*dstValue)[:0], value...)
}
if len(*dstValue) == 0 {
mn.RemoveTag(label)
}
}
return rvs, nil
}
func transformDropCommonLabels(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 1 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 1)
}
rvs := args[0]
for _, tss := range args[1:] {
rvs = append(rvs, tss...)
}
m := make(map[string]map[string]int)
countLabel := func(name, value string) {
x := m[name]
if x == nil {
x = make(map[string]int)
m[name] = x
}
x[value]++
}
for _, ts := range rvs {
countLabel("__name__", string(ts.MetricName.MetricGroup))
for _, tag := range ts.MetricName.Tags {
countLabel(string(tag.Key), string(tag.Value))
}
}
for labelName, x := range m {
for _, count := range x {
if count != len(rvs) {
continue
}
for _, ts := range rvs {
ts.MetricName.RemoveTag(labelName)
}
}
}
return rvs, nil
}
func transformLabelCopy(tfa *transformFuncArg) ([]*timeseries, error) {
return transformLabelCopyExt(tfa, false)
}
func transformLabelMove(tfa *transformFuncArg) ([]*timeseries, error) {
return transformLabelCopyExt(tfa, true)
}
func transformLabelCopyExt(tfa *transformFuncArg, removeSrcLabels bool) ([]*timeseries, error) {
args := tfa.args
if len(args) < 1 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 1)
}
srcLabels, dstLabels, err := getStringPairs(args[1:])
if err != nil {
return nil, err
}
rvs := args[0]
for _, ts := range rvs {
mn := &ts.MetricName
for i, srcLabel := range srcLabels {
dstLabel := dstLabels[i]
value := mn.GetTagValue(srcLabel)
if len(value) == 0 {
// Do not remove destination label if the source label doesn't exist.
continue
}
dstValue := getDstValue(mn, dstLabel)
*dstValue = append((*dstValue)[:0], value...)
if removeSrcLabels && srcLabel != dstLabel {
mn.RemoveTag(srcLabel)
}
}
}
return rvs, nil
}
func getStringPairs(args [][]*timeseries) ([]string, []string, error) {
if len(args)%2 != 0 {
return nil, nil, fmt.Errorf(`the number of string args must be even; got %d`, len(args))
}
var ks, vs []string
for i := 0; i < len(args); i += 2 {
k, err := getString(args[i], i)
if err != nil {
return nil, nil, err
}
ks = append(ks, k)
v, err := getString(args[i+1], i+1)
if err != nil {
return nil, nil, err
}
vs = append(vs, v)
}
return ks, vs, nil
}
func transformLabelJoin(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 3 {
return nil, fmt.Errorf(`not enough args; got %d; want at least %d`, len(args), 3)
}
dstLabel, err := getString(args[1], 1)
if err != nil {
return nil, err
}
separator, err := getString(args[2], 2)
if err != nil {
return nil, err
}
var srcLabels []string
for i := 3; i < len(args); i++ {
srcLabel, err := getString(args[i], i)
if err != nil {
return nil, err
}
srcLabels = append(srcLabels, srcLabel)
}
rvs := args[0]
for _, ts := range rvs {
mn := &ts.MetricName
dstValue := getDstValue(mn, dstLabel)
b := *dstValue
b = b[:0]
for j, srcLabel := range srcLabels {
srcValue := mn.GetTagValue(srcLabel)
b = append(b, srcValue...)
if j+1 < len(srcLabels) {
b = append(b, separator...)
}
}
*dstValue = b
if len(b) == 0 {
mn.RemoveTag(dstLabel)
}
}
return rvs, nil
}
func transformLabelTransform(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 4); err != nil {
return nil, err
}
label, err := getString(args[1], 1)
if err != nil {
return nil, err
}
regex, err := getString(args[2], 2)
if err != nil {
return nil, err
}
replacement, err := getString(args[3], 3)
if err != nil {
return nil, err
}
r, err := metricsql.CompileRegexp(regex)
if err != nil {
return nil, fmt.Errorf(`cannot compile regex %q: %w`, regex, err)
}
return labelReplace(args[0], label, r, label, replacement)
}
func transformLabelReplace(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 5); err != nil {
return nil, err
}
dstLabel, err := getString(args[1], 1)
if err != nil {
return nil, err
}
replacement, err := getString(args[2], 2)
if err != nil {
return nil, err
}
srcLabel, err := getString(args[3], 3)
if err != nil {
return nil, err
}
regex, err := getString(args[4], 4)
if err != nil {
return nil, err
}
r, err := metricsql.CompileRegexpAnchored(regex)
if err != nil {
return nil, fmt.Errorf(`cannot compile regex %q: %w`, regex, err)
}
return labelReplace(args[0], srcLabel, r, dstLabel, replacement)
}
func labelReplace(tss []*timeseries, srcLabel string, r *regexp.Regexp, dstLabel, replacement string) ([]*timeseries, error) {
replacementBytes := []byte(replacement)
for _, ts := range tss {
mn := &ts.MetricName
srcValue := mn.GetTagValue(srcLabel)
if !r.Match(srcValue) {
continue
}
b := r.ReplaceAll(srcValue, replacementBytes)
dstValue := getDstValue(mn, dstLabel)
*dstValue = append((*dstValue)[:0], b...)
if len(b) == 0 {
mn.RemoveTag(dstLabel)
}
}
return tss, nil
}
func transformLabelValue(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
labelName, err := getString(args[1], 1)
if err != nil {
return nil, fmt.Errorf("cannot get label name: %w", err)
}
rvs := args[0]
for _, ts := range rvs {
ts.MetricName.ResetMetricGroup()
labelValue := ts.MetricName.GetTagValue(labelName)
v, err := strconv.ParseFloat(string(labelValue), 64)
if err != nil {
v = nan
}
values := ts.Values
for i, vOrig := range values {
if !math.IsNaN(vOrig) {
values[i] = v
}
}
}
// Do not remove timeseries with only NaN values, so `default` could be applied to them:
// label_value(q, "label") default 123
return rvs, nil
}
func transformLabelMatch(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 3); err != nil {
return nil, err
}
labelName, err := getString(args[1], 1)
if err != nil {
return nil, fmt.Errorf("cannot get label name: %w", err)
}
labelRe, err := getString(args[2], 2)
if err != nil {
return nil, fmt.Errorf("cannot get regexp: %w", err)
}
r, err := metricsql.CompileRegexpAnchored(labelRe)
if err != nil {
return nil, fmt.Errorf(`cannot compile regexp %q: %w`, labelRe, err)
}
tss := args[0]
rvs := tss[:0]
for _, ts := range tss {
labelValue := ts.MetricName.GetTagValue(labelName)
if r.Match(labelValue) {
rvs = append(rvs, ts)
}
}
return rvs, nil
}
func transformLabelMismatch(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 3); err != nil {
return nil, err
}
labelName, err := getString(args[1], 1)
if err != nil {
return nil, fmt.Errorf("cannot get label name: %w", err)
}
labelRe, err := getString(args[2], 2)
if err != nil {
return nil, fmt.Errorf("cannot get regexp: %w", err)
}
r, err := metricsql.CompileRegexpAnchored(labelRe)
if err != nil {
return nil, fmt.Errorf(`cannot compile regexp %q: %w`, labelRe, err)
}
tss := args[0]
rvs := tss[:0]
for _, ts := range tss {
labelValue := ts.MetricName.GetTagValue(labelName)
if !r.Match(labelValue) {
rvs = append(rvs, ts)
}
}
return rvs, nil
}
func transformLabelGraphiteGroup(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 2 {
return nil, fmt.Errorf("unexpected number of args: %d; want at least 2 args", len(args))
}
tss := args[0]
groupArgs := args[1:]
groupIDs := make([]int, len(groupArgs))
for i, arg := range groupArgs {
groupID, err := getIntNumber(arg, i+1)
if err != nil {
return nil, fmt.Errorf("cannot get group name from arg #%d: %w", i+1, err)
}
groupIDs[i] = groupID
}
for _, ts := range tss {
groups := bytes.Split(ts.MetricName.MetricGroup, dotSeparator)
groupName := ts.MetricName.MetricGroup[:0]
for j, groupID := range groupIDs {
if groupID >= 0 && groupID < len(groups) {
groupName = append(groupName, groups[groupID]...)
}
if j < len(groupIDs)-1 {
groupName = append(groupName, '.')
}
}
ts.MetricName.MetricGroup = groupName
}
return tss, nil
}
var dotSeparator = []byte(".")
func transformLimitOffset(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 3); err != nil {
return nil, err
}
limit, err := getIntNumber(args[0], 0)
if err != nil {
return nil, fmt.Errorf("cannot obtain limit arg: %w", err)
}
offset, err := getIntNumber(args[1], 1)
if err != nil {
return nil, fmt.Errorf("cannot obtain offset arg: %w", err)
}
// removeEmptySeries so offset will be calculated after empty series
// were filtered out.
rvs := removeEmptySeries(args[2])
if len(rvs) >= offset {
rvs = rvs[offset:]
} else {
rvs = nil
}
if len(rvs) > limit {
rvs = rvs[:limit]
}
return rvs, nil
}
func transformLn(v float64) float64 {
return math.Log(v)
}
func transformLog2(v float64) float64 {
return math.Log2(v)
}
func transformLog10(v float64) float64 {
return math.Log10(v)
}
func transformMinute(t time.Time) int {
return t.Minute()
}
func transformMonth(t time.Time) int {
return int(t.Month())
}
func transformRound(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) != 1 && len(args) != 2 {
return nil, fmt.Errorf(`unexpected number of args: %d; want 1 or 2`, len(args))
}
var nearestArg []*timeseries
if len(args) == 1 {
nearestArg = evalNumber(tfa.ec, 1)
} else {
nearestArg = args[1]
}
nearest, err := getScalar(nearestArg, 1)
if err != nil {
return nil, err
}
tf := func(values []float64) {
var nPrev float64
var p10 float64
for i, v := range values {
n := nearest[i]
if n != nPrev {
nPrev = n
_, e := decimal.FromFloat(n)
p10 = math.Pow10(int(-e))
}
v += 0.5 * math.Copysign(n, v)
v -= math.Mod(v, n)
v, _ = math.Modf(v * p10)
values[i] = v / p10
}
}
return doTransformValues(args[0], tf, tfa.fe)
}
func transformSgn(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
tf := func(values []float64) {
for i, v := range values {
sign := float64(0)
if v < 0 {
sign = -1
} else if v > 0 {
sign = 1
}
values[i] = sign
}
}
return doTransformValues(args[0], tf, tfa.fe)
}
func transformScalar(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
// Verify whether the arg is a string.
// Then try converting the string to number.
if se, ok := tfa.fe.Args[0].(*metricsql.StringExpr); ok {
n, err := strconv.ParseFloat(se.S, 64)
if err != nil {
n = nan
}
return evalNumber(tfa.ec, n), nil
}
// The arg isn't a string. Extract scalar from it.
arg := args[0]
if len(arg) != 1 {
return evalNumber(tfa.ec, nan), nil
}
arg[0].MetricName.Reset()
return arg, nil
}
func newTransformFuncSortByLabel(isDesc bool) transformFunc {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 2 {
return nil, fmt.Errorf("expecting at least 2 args; got %d args", len(args))
}
var labels []string
for i, arg := range args[1:] {
label, err := getString(arg, 1)
if err != nil {
return nil, fmt.Errorf("cannot parse label #%d for sorting: %w", i+1, err)
}
labels = append(labels, label)
}
rvs := args[0]
sort.SliceStable(rvs, func(i, j int) bool {
for _, label := range labels {
a := rvs[i].MetricName.GetTagValue(label)
b := rvs[j].MetricName.GetTagValue(label)
if string(a) == string(b) {
continue
}
if isDesc {
return string(b) < string(a)
}
return string(a) < string(b)
}
return false
})
return rvs, nil
}
}
func newTransformFuncNumericSort(isDesc bool) transformFunc {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) < 2 {
return nil, fmt.Errorf("expecting at least 2 args; got %d args", len(args))
}
var labels []string
for i, arg := range args[1:] {
label, err := getString(arg, i+1)
if err != nil {
return nil, fmt.Errorf("cannot parse label #%d for sorting: %w", i+1, err)
}
labels = append(labels, label)
}
rvs := args[0]
sort.SliceStable(rvs, func(i, j int) bool {
for _, label := range labels {
a := rvs[i].MetricName.GetTagValue(label)
b := rvs[j].MetricName.GetTagValue(label)
if string(a) == string(b) {
continue
}
aStr := bytesutil.ToUnsafeString(a)
bStr := bytesutil.ToUnsafeString(b)
if isDesc {
return numericLess(bStr, aStr)
}
return numericLess(aStr, bStr)
}
return false
})
return rvs, nil
}
}
func numericLess(a, b string) bool {
for {
if len(b) == 0 {
return false
}
if len(a) == 0 {
return true
}
aPrefix := getNumPrefix(a)
bPrefix := getNumPrefix(b)
a = a[len(aPrefix):]
b = b[len(bPrefix):]
if len(aPrefix) > 0 || len(bPrefix) > 0 {
if len(aPrefix) == 0 {
return false
}
if len(bPrefix) == 0 {
return true
}
aNum := mustParseNum(aPrefix)
bNum := mustParseNum(bPrefix)
if aNum != bNum {
return aNum < bNum
}
}
aPrefix = getNonNumPrefix(a)
bPrefix = getNonNumPrefix(b)
a = a[len(aPrefix):]
b = b[len(bPrefix):]
if aPrefix != bPrefix {
return aPrefix < bPrefix
}
}
}
func getNumPrefix(s string) string {
i := 0
if len(s) > 0 {
switch s[0] {
case '-', '+':
i++
}
}
hasNum := false
hasDot := false
for i < len(s) {
if !isDecimalChar(s[i]) {
if !hasDot && s[i] == '.' {
hasDot = true
i++
continue
}
if !hasNum {
return ""
}
return s[:i]
}
hasNum = true
i++
}
if !hasNum {
return ""
}
return s
}
func getNonNumPrefix(s string) string {
i := 0
for i < len(s) {
if isDecimalChar(s[i]) {
return s[:i]
}
i++
}
return s
}
func isDecimalChar(ch byte) bool {
return ch >= '0' && ch <= '9'
}
func mustParseNum(s string) float64 {
f, err := strconv.ParseFloat(s, 64)
if err != nil {
logger.Panicf("BUG: unexpected error when parsing the number %q: %s", s, err)
}
return f
}
func newTransformFuncSort(isDesc bool) transformFunc {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
sort.Slice(rvs, func(i, j int) bool {
a := rvs[i].Values
b := rvs[j].Values
n := len(a) - 1
for n >= 0 {
if !math.IsNaN(a[n]) {
if math.IsNaN(b[n]) {
return false
}
if a[n] != b[n] {
break
}
} else if !math.IsNaN(b[n]) {
return true
}
n--
}
if n < 0 {
return false
}
if isDesc {
return b[n] < a[n]
}
return a[n] < b[n]
})
return rvs, nil
}
}
func transformSqrt(v float64) float64 {
return math.Sqrt(v)
}
func transformSin(v float64) float64 {
return math.Sin(v)
}
func transformSinh(v float64) float64 {
return math.Sinh(v)
}
func transformCos(v float64) float64 {
return math.Cos(v)
}
func transformCosh(v float64) float64 {
return math.Cosh(v)
}
func transformTan(v float64) float64 {
return math.Tan(v)
}
func transformTanh(v float64) float64 {
return math.Tanh(v)
}
func transformAsin(v float64) float64 {
return math.Asin(v)
}
func transformAsinh(v float64) float64 {
return math.Asinh(v)
}
func transformAtan(v float64) float64 {
return math.Atan(v)
}
func transformAtanh(v float64) float64 {
return math.Atanh(v)
}
func transformAcos(v float64) float64 {
return math.Acos(v)
}
func transformAcosh(v float64) float64 {
return math.Acosh(v)
}
func transformDeg(v float64) float64 {
return v * 180 / math.Pi
}
func transformRad(v float64) float64 {
return v * math.Pi / 180
}
func newTransformRand(newRandFunc func(r *rand.Rand) func() float64) transformFunc {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if len(args) > 1 {
return nil, fmt.Errorf(`unexpected number of args; got %d; want 0 or 1`, len(args))
}
var seed int64
if len(args) == 1 {
tmp, err := getScalar(args[0], 0)
if err != nil {
return nil, err
}
if len(tmp) > 0 {
seed = int64(tmp[0])
}
} else {
seed = time.Now().UnixNano()
}
source := rand.NewSource(seed)
r := rand.New(source)
randFunc := newRandFunc(r)
tss := evalNumber(tfa.ec, 0)
values := tss[0].Values
for i := range values {
values[i] = randFunc()
}
return tss, nil
}
}
func newRandFloat64(r *rand.Rand) func() float64 {
return r.Float64
}
func newRandNormFloat64(r *rand.Rand) func() float64 {
return r.NormFloat64
}
func newRandExpFloat64(r *rand.Rand) func() float64 {
return r.ExpFloat64
}
func transformPi(tfa *transformFuncArg) ([]*timeseries, error) {
if err := expectTransformArgsNum(tfa.args, 0); err != nil {
return nil, err
}
return evalNumber(tfa.ec, math.Pi), nil
}
func transformNow(tfa *transformFuncArg) ([]*timeseries, error) {
if err := expectTransformArgsNum(tfa.args, 0); err != nil {
return nil, err
}
now := float64(time.Now().UnixNano()) / 1e9
return evalNumber(tfa.ec, now), nil
}
func bitmapAnd(a, b uint64) uint64 {
return a & b
}
func bitmapOr(a, b uint64) uint64 {
return a | b
}
func bitmapXor(a, b uint64) uint64 {
return a ^ b
}
func newTransformBitmap(bitmapFunc func(a, b uint64) uint64) func(tfa *transformFuncArg) ([]*timeseries, error) {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 2); err != nil {
return nil, err
}
ns, err := getScalar(args[1], 1)
if err != nil {
return nil, err
}
tf := func(values []float64) {
for i, v := range values {
values[i] = float64(bitmapFunc(uint64(v), uint64(ns[i])))
}
}
return doTransformValues(args[0], tf, tfa.fe)
}
}
func transformTimezoneOffset(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
tzString, err := getString(args[0], 0)
if err != nil {
return nil, fmt.Errorf("cannot get timezone name: %w", err)
}
loc, err := time.LoadLocation(tzString)
if err != nil {
return nil, fmt.Errorf("cannot load timezone %q: %w", tzString, err)
}
tss := evalNumber(tfa.ec, nan)
ts := tss[0]
for i, timestamp := range ts.Timestamps {
_, offset := time.Unix(timestamp/1000, 0).In(loc).Zone()
ts.Values[i] = float64(offset)
}
return tss, nil
}
func transformTime(tfa *transformFuncArg) ([]*timeseries, error) {
if err := expectTransformArgsNum(tfa.args, 0); err != nil {
return nil, err
}
return evalTime(tfa.ec), nil
}
func transformVector(tfa *transformFuncArg) ([]*timeseries, error) {
args := tfa.args
if err := expectTransformArgsNum(args, 1); err != nil {
return nil, err
}
rvs := args[0]
return rvs, nil
}
func transformYear(t time.Time) int {
return t.Year()
}
func newTransformFuncZeroArgs(f func(tfa *transformFuncArg) float64) transformFunc {
return func(tfa *transformFuncArg) ([]*timeseries, error) {
if err := expectTransformArgsNum(tfa.args, 0); err != nil {
return nil, err
}
v := f(tfa)
return evalNumber(tfa.ec, v), nil
}
}
func transformStep(tfa *transformFuncArg) float64 {
return float64(tfa.ec.Step) / 1e3
}
func transformStart(tfa *transformFuncArg) float64 {
return float64(tfa.ec.Start) / 1e3
}
func transformEnd(tfa *transformFuncArg) float64 {
return float64(tfa.ec.End) / 1e3
}
// copyTimeseries returns a copy of tss.
func copyTimeseries(tss []*timeseries) []*timeseries {
rvs := make([]*timeseries, len(tss))
for i, src := range tss {
var dst timeseries
dst.CopyFromShallowTimestamps(src)
rvs[i] = &dst
}
return rvs
}
// copyTimeseriesMetricNames returns a copy of tss with real copy of MetricNames,
// but with shallow copy of Timestamps and Values if makeCopy is set.
//
// Otherwise tss is returned.
func copyTimeseriesMetricNames(tss []*timeseries, makeCopy bool) []*timeseries {
if !makeCopy {
return tss
}
rvs := make([]*timeseries, len(tss))
for i, src := range tss {
var dst timeseries
dst.CopyFromMetricNames(src)
rvs[i] = &dst
}
return rvs
}
// copyTimeseriesShallow returns a copy of arg with shallow copies of MetricNames,
// Timestamps and Values.
func copyTimeseriesShallow(arg []*timeseries) []*timeseries {
rvs := make([]*timeseries, len(arg))
for i, src := range arg {
var dst timeseries
dst.CopyShallow(src)
rvs[i] = &dst
}
return rvs
}
func getDstValue(mn *storage.MetricName, dstLabel string) *[]byte {
if dstLabel == "__name__" {
return &mn.MetricGroup
}
tags := mn.Tags
for i := range tags {
tag := &tags[i]
if string(tag.Key) == dstLabel {
return &tag.Value
}
}
if len(tags) < cap(tags) {
tags = tags[:len(tags)+1]
} else {
tags = append(tags, storage.Tag{})
}
mn.Tags = tags
tag := &tags[len(tags)-1]
tag.Key = append(tag.Key[:0], dstLabel...)
return &tag.Value
}
func isLeapYear(y uint32) bool {
if y%4 != 0 {
return false
}
if y%100 != 0 {
return true
}
return y%400 == 0
}
var daysInMonth = [...]int{
time.January: 31,
time.February: 28,
time.March: 31,
time.April: 30,
time.May: 31,
time.June: 30,
time.July: 31,
time.August: 31,
time.September: 30,
time.October: 31,
time.November: 30,
time.December: 31,
}
func expectTransformArgsNum(args [][]*timeseries, expectedNum int) error {
if len(args) == expectedNum {
return nil
}
return fmt.Errorf(`unexpected number of args; got %d; want %d`, len(args), expectedNum)
}
func removeCounterResetsMaybeNaNs(values []float64) {
values = skipLeadingNaNs(values)
if len(values) == 0 {
return
}
var correction float64
prevValue := values[0]
for i, v := range values {
if math.IsNaN(v) {
continue
}
d := v - prevValue
if d < 0 {
if (-d * 8) < prevValue {
// This is likely a partial counter reset.
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2787
correction += prevValue - v
} else {
correction += prevValue
}
}
prevValue = v
values[i] = v + correction
}
}