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prometheus/promql/functions.go

1648 lines
53 KiB

// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promql
import (
"fmt"
"math"
"sort"
"strconv"
"strings"
"time"
"github.com/grafana/regexp"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/model/histogram"
"github.com/prometheus/prometheus/model/labels"
"github.com/prometheus/prometheus/promql/parser"
"github.com/prometheus/prometheus/promql/parser/posrange"
"github.com/prometheus/prometheus/util/annotations"
)
// FunctionCall is the type of a PromQL function implementation
//
// vals is a list of the evaluated arguments for the function call.
//
// For range vectors it will be a Matrix with one series, instant vectors a
// Vector, scalars a Vector with one series whose value is the scalar
// value,and nil for strings.
//
// args are the original arguments to the function, where you can access
// matrixSelectors, vectorSelectors, and StringLiterals.
//
// enh.Out is a pre-allocated empty vector that you may use to accumulate
// output before returning it. The vectors in vals should not be returned.a
//
// Range vector functions need only return a vector with the right value,
// the metric and timestamp are not needed.
//
// Instant vector functions need only return a vector with the right values and
// metrics, the timestamp are not needed.
//
// Scalar results should be returned as the value of a sample in a Vector.
type FunctionCall func(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations)
// === time() float64 ===
func funcTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return Vector{Sample{
F: float64(enh.Ts) / 1000,
}}, nil
}
// extrapolatedRate is a utility function for rate/increase/delta.
// It calculates the rate (allowing for counter resets if isCounter is true),
// extrapolates if the first/last sample is close to the boundary, and returns
// the result as either per-second (if isRate is true) or overall.
func extrapolatedRate(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper, isCounter, isRate bool) (Vector, annotations.Annotations) {
ms := args[0].(*parser.MatrixSelector)
vs := ms.VectorSelector.(*parser.VectorSelector)
var (
samples = vals[0].(Matrix)[0]
rangeStart = enh.Ts - durationMilliseconds(ms.Range+vs.Offset)
rangeEnd = enh.Ts - durationMilliseconds(vs.Offset)
resultFloat float64
resultHistogram *histogram.FloatHistogram
firstT, lastT int64
numSamplesMinusOne int
annos = annotations.Annotations{}
)
// We need either at least two Histograms and no Floats, or at least two
// Floats and no Histograms to calculate a rate. Otherwise, drop this
// Vector element.
metricName := samples.Metric.Get(labels.MetricName)
if len(samples.Histograms) > 0 && len(samples.Floats) > 0 {
return enh.Out, annos.Add(annotations.NewMixedFloatsHistogramsWarning(metricName, args[0].PositionRange()))
}
if isCounter && metricName != "" && len(samples.Floats) > 0 &&
!strings.HasSuffix(metricName, "_total") &&
!strings.HasSuffix(metricName, "_sum") &&
!strings.HasSuffix(metricName, "_count") &&
!strings.HasSuffix(metricName, "_bucket") {
annos.Add(annotations.NewPossibleNonCounterInfo(metricName, args[0].PositionRange()))
}
switch {
case len(samples.Histograms) > 1:
numSamplesMinusOne = len(samples.Histograms) - 1
firstT = samples.Histograms[0].T
lastT = samples.Histograms[numSamplesMinusOne].T
var newAnnos annotations.Annotations
resultHistogram, newAnnos = histogramRate(samples.Histograms, isCounter, metricName, args[0].PositionRange())
if resultHistogram == nil {
// The histograms are not compatible with each other.
return enh.Out, annos.Merge(newAnnos)
}
case len(samples.Floats) > 1:
numSamplesMinusOne = len(samples.Floats) - 1
firstT = samples.Floats[0].T
lastT = samples.Floats[numSamplesMinusOne].T
resultFloat = samples.Floats[numSamplesMinusOne].F - samples.Floats[0].F
if !isCounter {
break
}
// Handle counter resets:
prevValue := samples.Floats[0].F
for _, currPoint := range samples.Floats[1:] {
if currPoint.F < prevValue {
resultFloat += prevValue
}
prevValue = currPoint.F
}
default:
// TODO: add RangeTooShortWarning
return enh.Out, annos
}
// Duration between first/last samples and boundary of range.
durationToStart := float64(firstT-rangeStart) / 1000
durationToEnd := float64(rangeEnd-lastT) / 1000
sampledInterval := float64(lastT-firstT) / 1000
averageDurationBetweenSamples := sampledInterval / float64(numSamplesMinusOne)
// TODO(beorn7): Do this for histograms, too.
if isCounter && resultFloat > 0 && len(samples.Floats) > 0 && samples.Floats[0].F >= 0 {
// Counters cannot be negative. If we have any slope at all
// (i.e. resultFloat went up), we can extrapolate the zero point
// of the counter. If the duration to the zero point is shorter
// than the durationToStart, we take the zero point as the start
// of the series, thereby avoiding extrapolation to negative
// counter values.
durationToZero := sampledInterval * (samples.Floats[0].F / resultFloat)
if durationToZero < durationToStart {
durationToStart = durationToZero
}
}
// If the first/last samples are close to the boundaries of the range,
// extrapolate the result. This is as we expect that another sample
// will exist given the spacing between samples we've seen thus far,
// with an allowance for noise.
extrapolationThreshold := averageDurationBetweenSamples * 1.1
extrapolateToInterval := sampledInterval
if durationToStart < extrapolationThreshold {
extrapolateToInterval += durationToStart
} else {
extrapolateToInterval += averageDurationBetweenSamples / 2
}
if durationToEnd < extrapolationThreshold {
extrapolateToInterval += durationToEnd
} else {
extrapolateToInterval += averageDurationBetweenSamples / 2
}
factor := extrapolateToInterval / sampledInterval
if isRate {
factor /= ms.Range.Seconds()
}
if resultHistogram == nil {
resultFloat *= factor
} else {
resultHistogram.Mul(factor)
}
return append(enh.Out, Sample{F: resultFloat, H: resultHistogram}), annos
}
// histogramRate is a helper function for extrapolatedRate. It requires
// points[0] to be a histogram. It returns nil if any other Point in points is
// not a histogram, and a warning wrapped in an annotation in that case.
// Otherwise, it returns the calculated histogram and an empty annotation.
func histogramRate(points []HPoint, isCounter bool, metricName string, pos posrange.PositionRange) (*histogram.FloatHistogram, annotations.Annotations) {
prev := points[0].H
last := points[len(points)-1].H
if last == nil {
return nil, annotations.New().Add(annotations.NewMixedFloatsHistogramsWarning(metricName, pos))
}
minSchema := prev.Schema
if last.Schema < minSchema {
minSchema = last.Schema
}
// First iteration to find out two things:
// - What's the smallest relevant schema?
// - Are all data points histograms?
// TODO(beorn7): Find a way to check that earlier, e.g. by handing in a
// []FloatPoint and a []HistogramPoint separately.
for _, currPoint := range points[1 : len(points)-1] {
curr := currPoint.H
if curr == nil {
return nil, annotations.New().Add(annotations.NewMixedFloatsHistogramsWarning(metricName, pos))
}
// TODO(trevorwhitney): Check if isCounter is consistent with curr.CounterResetHint.
if !isCounter {
continue
}
if curr.Schema < minSchema {
minSchema = curr.Schema
}
}
h := last.CopyToSchema(minSchema)
h.Sub(prev)
if isCounter {
// Second iteration to deal with counter resets.
for _, currPoint := range points[1:] {
curr := currPoint.H
if curr.DetectReset(prev) {
h.Add(prev)
}
prev = curr
}
}
h.CounterResetHint = histogram.GaugeType
return h.Compact(0), nil
}
// === delta(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcDelta(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return extrapolatedRate(vals, args, enh, false, false)
}
// === rate(node parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcRate(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return extrapolatedRate(vals, args, enh, true, true)
}
// === increase(node parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcIncrease(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return extrapolatedRate(vals, args, enh, true, false)
}
// === irate(node parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcIrate(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return instantValue(vals, enh.Out, true)
}
// === idelta(node model.ValMatrix) (Vector, Annotations) ===
func funcIdelta(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return instantValue(vals, enh.Out, false)
}
func instantValue(vals []parser.Value, out Vector, isRate bool) (Vector, annotations.Annotations) {
samples := vals[0].(Matrix)[0]
// No sense in trying to compute a rate without at least two points. Drop
// this Vector element.
// TODO: add RangeTooShortWarning
if len(samples.Floats) < 2 {
return out, nil
}
lastSample := samples.Floats[len(samples.Floats)-1]
previousSample := samples.Floats[len(samples.Floats)-2]
var resultValue float64
if isRate && lastSample.F < previousSample.F {
// Counter reset.
resultValue = lastSample.F
} else {
resultValue = lastSample.F - previousSample.F
}
sampledInterval := lastSample.T - previousSample.T
if sampledInterval == 0 {
// Avoid dividing by 0.
return out, nil
}
if isRate {
// Convert to per-second.
resultValue /= float64(sampledInterval) / 1000
}
return append(out, Sample{F: resultValue}), nil
}
// Calculate the trend value at the given index i in raw data d.
// This is somewhat analogous to the slope of the trend at the given index.
// The argument "tf" is the trend factor.
// The argument "s0" is the computed smoothed value.
// The argument "s1" is the computed trend factor.
// The argument "b" is the raw input value.
func calcTrendValue(i int, tf, s0, s1, b float64) float64 {
if i == 0 {
return b
}
x := tf * (s1 - s0)
y := (1 - tf) * b
return x + y
}
// Holt-Winters is similar to a weighted moving average, where historical data has exponentially less influence on the current data.
// Holt-Winter also accounts for trends in data. The smoothing factor (0 < sf < 1) affects how historical data will affect the current
// data. A lower smoothing factor increases the influence of historical data. The trend factor (0 < tf < 1) affects
// how trends in historical data will affect the current data. A higher trend factor increases the influence.
// of trends. Algorithm taken from https://en.wikipedia.org/wiki/Exponential_smoothing titled: "Double exponential smoothing".
func funcHoltWinters(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
samples := vals[0].(Matrix)[0]
// The smoothing factor argument.
sf := vals[1].(Vector)[0].F
// The trend factor argument.
tf := vals[2].(Vector)[0].F
// Check that the input parameters are valid.
if sf <= 0 || sf >= 1 {
panic(fmt.Errorf("invalid smoothing factor. Expected: 0 < sf < 1, got: %f", sf))
}
if tf <= 0 || tf >= 1 {
panic(fmt.Errorf("invalid trend factor. Expected: 0 < tf < 1, got: %f", tf))
}
l := len(samples.Floats)
// Can't do the smoothing operation with less than two points.
if l < 2 {
return enh.Out, nil
}
var s0, s1, b float64
// Set initial values.
s1 = samples.Floats[0].F
b = samples.Floats[1].F - samples.Floats[0].F
// Run the smoothing operation.
var x, y float64
for i := 1; i < l; i++ {
// Scale the raw value against the smoothing factor.
x = sf * samples.Floats[i].F
// Scale the last smoothed value with the trend at this point.
b = calcTrendValue(i-1, tf, s0, s1, b)
y = (1 - sf) * (s1 + b)
s0, s1 = s1, x+y
}
return append(enh.Out, Sample{F: s1}), nil
}
// === sort(node parser.ValueTypeVector) (Vector, Annotations) ===
func funcSort(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
// NaN should sort to the bottom, so take descending sort with NaN first and
// reverse it.
byValueSorter := vectorByReverseValueHeap(vals[0].(Vector))
sort.Sort(sort.Reverse(byValueSorter))
return Vector(byValueSorter), nil
}
// === sortDesc(node parser.ValueTypeVector) (Vector, Annotations) ===
func funcSortDesc(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
// NaN should sort to the bottom, so take ascending sort with NaN first and
// reverse it.
byValueSorter := vectorByValueHeap(vals[0].(Vector))
sort.Sort(sort.Reverse(byValueSorter))
return Vector(byValueSorter), nil
}
// === clamp(Vector parser.ValueTypeVector, min, max Scalar) (Vector, Annotations) ===
func funcClamp(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
vec := vals[0].(Vector)
min := vals[1].(Vector)[0].F
max := vals[2].(Vector)[0].F
if max < min {
return enh.Out, nil
}
for _, el := range vec {
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(el.Metric),
F: math.Max(min, math.Min(max, el.F)),
})
}
return enh.Out, nil
}
// === clamp_max(Vector parser.ValueTypeVector, max Scalar) (Vector, Annotations) ===
func funcClampMax(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
vec := vals[0].(Vector)
max := vals[1].(Vector)[0].F
for _, el := range vec {
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(el.Metric),
F: math.Min(max, el.F),
})
}
return enh.Out, nil
}
// === clamp_min(Vector parser.ValueTypeVector, min Scalar) (Vector, Annotations) ===
func funcClampMin(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
vec := vals[0].(Vector)
min := vals[1].(Vector)[0].F
for _, el := range vec {
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(el.Metric),
F: math.Max(min, el.F),
})
}
return enh.Out, nil
}
// === round(Vector parser.ValueTypeVector, toNearest=1 Scalar) (Vector, Annotations) ===
func funcRound(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
vec := vals[0].(Vector)
// round returns a number rounded to toNearest.
// Ties are solved by rounding up.
toNearest := float64(1)
if len(args) >= 2 {
toNearest = vals[1].(Vector)[0].F
}
// Invert as it seems to cause fewer floating point accuracy issues.
toNearestInverse := 1.0 / toNearest
for _, el := range vec {
f := math.Floor(el.F*toNearestInverse+0.5) / toNearestInverse
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(el.Metric),
F: f,
})
}
return enh.Out, nil
}
// === Scalar(node parser.ValueTypeVector) Scalar ===
func funcScalar(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
v := vals[0].(Vector)
if len(v) != 1 {
return append(enh.Out, Sample{F: math.NaN()}), nil
}
return append(enh.Out, Sample{F: v[0].F}), nil
}
func aggrOverTime(vals []parser.Value, enh *EvalNodeHelper, aggrFn func(Series) float64) Vector {
el := vals[0].(Matrix)[0]
return append(enh.Out, Sample{F: aggrFn(el)})
}
func aggrHistOverTime(vals []parser.Value, enh *EvalNodeHelper, aggrFn func(Series) *histogram.FloatHistogram) Vector {
el := vals[0].(Matrix)[0]
return append(enh.Out, Sample{H: aggrFn(el)})
}
// === avg_over_time(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcAvgOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
firstSeries := vals[0].(Matrix)[0]
if len(firstSeries.Floats) > 0 && len(firstSeries.Histograms) > 0 {
metricName := firstSeries.Metric.Get(labels.MetricName)
return enh.Out, annotations.New().Add(annotations.NewMixedFloatsHistogramsWarning(metricName, args[0].PositionRange()))
}
if len(firstSeries.Floats) == 0 {
// The passed values only contain histograms.
return aggrHistOverTime(vals, enh, func(s Series) *histogram.FloatHistogram {
count := 1
mean := s.Histograms[0].H.Copy()
for _, h := range s.Histograms[1:] {
count++
left := h.H.Copy().Div(float64(count))
right := mean.Copy().Div(float64(count))
// The histogram being added/subtracted must have
// an equal or larger schema.
if h.H.Schema >= mean.Schema {
toAdd := right.Mul(-1).Add(left)
mean.Add(toAdd)
} else {
toAdd := left.Sub(right)
mean = toAdd.Add(mean)
}
}
return mean
}), nil
}
return aggrOverTime(vals, enh, func(s Series) float64 {
var mean, count, c float64
for _, f := range s.Floats {
count++
if math.IsInf(mean, 0) {
if math.IsInf(f.F, 0) && (mean > 0) == (f.F > 0) {
// The `mean` and `f.F` values are `Inf` of the same sign. They
// can't be subtracted, but the value of `mean` is correct
// already.
continue
}
if !math.IsInf(f.F, 0) && !math.IsNaN(f.F) {
// At this stage, the mean is an infinite. If the added
// value is neither an Inf or a Nan, we can keep that mean
// value.
// This is required because our calculation below removes
// the mean value, which would look like Inf += x - Inf and
// end up as a NaN.
continue
}
}
mean, c = kahanSumInc(f.F/count-mean/count, mean, c)
}
if math.IsInf(mean, 0) {
return mean
}
return mean + c
}), nil
}
// === count_over_time(Matrix parser.ValueTypeMatrix) (Vector, Notes) ===
func funcCountOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return aggrOverTime(vals, enh, func(s Series) float64 {
return float64(len(s.Floats) + len(s.Histograms))
}), nil
}
// === last_over_time(Matrix parser.ValueTypeMatrix) (Vector, Notes) ===
func funcLastOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
el := vals[0].(Matrix)[0]
var f FPoint
if len(el.Floats) > 0 {
f = el.Floats[len(el.Floats)-1]
}
var h HPoint
if len(el.Histograms) > 0 {
h = el.Histograms[len(el.Histograms)-1]
}
if h.H == nil || h.T < f.T {
return append(enh.Out, Sample{
Metric: el.Metric,
F: f.F,
}), nil
}
return append(enh.Out, Sample{
Metric: el.Metric,
H: h.H,
}), nil
}
// === max_over_time(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcMaxOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
if len(vals[0].(Matrix)[0].Floats) == 0 {
// TODO(beorn7): The passed values only contain
// histograms. max_over_time ignores histograms for now. If
// there are only histograms, we have to return without adding
// anything to enh.Out.
return enh.Out, nil
}
return aggrOverTime(vals, enh, func(s Series) float64 {
max := s.Floats[0].F
for _, f := range s.Floats {
if f.F > max || math.IsNaN(max) {
max = f.F
}
}
return max
}), nil
}
// === min_over_time(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcMinOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
if len(vals[0].(Matrix)[0].Floats) == 0 {
// TODO(beorn7): The passed values only contain
// histograms. min_over_time ignores histograms for now. If
// there are only histograms, we have to return without adding
// anything to enh.Out.
return enh.Out, nil
}
return aggrOverTime(vals, enh, func(s Series) float64 {
min := s.Floats[0].F
for _, f := range s.Floats {
if f.F < min || math.IsNaN(min) {
min = f.F
}
}
return min
}), nil
}
// === sum_over_time(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcSumOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
firstSeries := vals[0].(Matrix)[0]
if len(firstSeries.Floats) > 0 && len(firstSeries.Histograms) > 0 {
metricName := firstSeries.Metric.Get(labels.MetricName)
return enh.Out, annotations.New().Add(annotations.NewMixedFloatsHistogramsWarning(metricName, args[0].PositionRange()))
}
if len(firstSeries.Floats) == 0 {
// The passed values only contain histograms.
return aggrHistOverTime(vals, enh, func(s Series) *histogram.FloatHistogram {
sum := s.Histograms[0].H.Copy()
for _, h := range s.Histograms[1:] {
// The histogram being added must have
// an equal or larger schema.
if h.H.Schema >= sum.Schema {
sum.Add(h.H)
} else {
sum = h.H.Copy().Add(sum)
}
}
return sum
}), nil
}
return aggrOverTime(vals, enh, func(s Series) float64 {
var sum, c float64
for _, f := range s.Floats {
sum, c = kahanSumInc(f.F, sum, c)
}
if math.IsInf(sum, 0) {
return sum
}
return sum + c
}), nil
}
// === quantile_over_time(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcQuantileOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
q := vals[0].(Vector)[0].F
el := vals[1].(Matrix)[0]
if len(el.Floats) == 0 {
// TODO(beorn7): The passed values only contain
// histograms. quantile_over_time ignores histograms for now. If
// there are only histograms, we have to return without adding
// anything to enh.Out.
return enh.Out, nil
}
annos := annotations.Annotations{}
if math.IsNaN(q) || q < 0 || q > 1 {
annos.Add(annotations.NewInvalidQuantileWarning(q, args[0].PositionRange()))
}
values := make(vectorByValueHeap, 0, len(el.Floats))
for _, f := range el.Floats {
values = append(values, Sample{F: f.F})
}
return append(enh.Out, Sample{F: quantile(q, values)}), annos
}
// === stddev_over_time(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcStddevOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
if len(vals[0].(Matrix)[0].Floats) == 0 {
// TODO(beorn7): The passed values only contain
// histograms. stddev_over_time ignores histograms for now. If
// there are only histograms, we have to return without adding
// anything to enh.Out.
return enh.Out, nil
}
return aggrOverTime(vals, enh, func(s Series) float64 {
var count float64
var mean, cMean float64
var aux, cAux float64
for _, f := range s.Floats {
count++
delta := f.F - (mean + cMean)
mean, cMean = kahanSumInc(delta/count, mean, cMean)
aux, cAux = kahanSumInc(delta*(f.F-(mean+cMean)), aux, cAux)
}
return math.Sqrt((aux + cAux) / count)
}), nil
}
// === stdvar_over_time(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcStdvarOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
if len(vals[0].(Matrix)[0].Floats) == 0 {
// TODO(beorn7): The passed values only contain
// histograms. stdvar_over_time ignores histograms for now. If
// there are only histograms, we have to return without adding
// anything to enh.Out.
return enh.Out, nil
}
return aggrOverTime(vals, enh, func(s Series) float64 {
var count float64
var mean, cMean float64
var aux, cAux float64
for _, f := range s.Floats {
count++
delta := f.F - (mean + cMean)
mean, cMean = kahanSumInc(delta/count, mean, cMean)
aux, cAux = kahanSumInc(delta*(f.F-(mean+cMean)), aux, cAux)
}
return (aux + cAux) / count
}), nil
}
// === absent(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAbsent(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
if len(vals[0].(Vector)) > 0 {
return enh.Out, nil
}
return append(enh.Out,
Sample{
Metric: createLabelsForAbsentFunction(args[0]),
F: 1,
}), nil
}
// === absent_over_time(Vector parser.ValueTypeMatrix) (Vector, Annotations) ===
// As this function has a matrix as argument, it does not get all the Series.
// This function will return 1 if the matrix has at least one element.
// Due to engine optimization, this function is only called when this condition is true.
// Then, the engine post-processes the results to get the expected output.
func funcAbsentOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return append(enh.Out, Sample{F: 1}), nil
}
// === present_over_time(Vector parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcPresentOverTime(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return aggrOverTime(vals, enh, func(s Series) float64 {
return 1
}), nil
}
func simpleFunc(vals []parser.Value, enh *EvalNodeHelper, f func(float64) float64) Vector {
for _, el := range vals[0].(Vector) {
if el.H == nil { // Process only float samples.
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(el.Metric),
F: f(el.F),
})
}
}
return enh.Out
}
// === abs(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAbs(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Abs), nil
}
// === ceil(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcCeil(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Ceil), nil
}
// === floor(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcFloor(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Floor), nil
}
// === exp(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcExp(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Exp), nil
}
// === sqrt(Vector VectorNode) (Vector, Annotations) ===
func funcSqrt(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Sqrt), nil
}
// === ln(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcLn(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Log), nil
}
// === log2(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcLog2(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Log2), nil
}
// === log10(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcLog10(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Log10), nil
}
// === sin(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcSin(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Sin), nil
}
// === cos(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcCos(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Cos), nil
}
// === tan(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcTan(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Tan), nil
}
// === asin(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAsin(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Asin), nil
}
// === acos(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAcos(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Acos), nil
}
// === atan(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAtan(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Atan), nil
}
// === sinh(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcSinh(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Sinh), nil
}
// === cosh(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcCosh(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Cosh), nil
}
// === tanh(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcTanh(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Tanh), nil
}
// === asinh(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAsinh(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Asinh), nil
}
// === acosh(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAcosh(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Acosh), nil
}
// === atanh(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcAtanh(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, math.Atanh), nil
}
// === rad(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcRad(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, func(v float64) float64 {
return v * math.Pi / 180
}), nil
}
// === deg(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcDeg(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, func(v float64) float64 {
return v * 180 / math.Pi
}), nil
}
// === pi() Scalar ===
func funcPi(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return Vector{Sample{F: math.Pi}}, nil
}
// === sgn(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcSgn(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return simpleFunc(vals, enh, func(v float64) float64 {
switch {
case v < 0:
return -1
case v > 0:
return 1
default:
return v
}
}), nil
}
// === timestamp(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcTimestamp(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
vec := vals[0].(Vector)
for _, el := range vec {
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(el.Metric),
F: float64(el.T) / 1000,
})
}
return enh.Out, nil
}
func kahanSum(samples []float64) float64 {
var sum, c float64
for _, v := range samples {
sum, c = kahanSumInc(v, sum, c)
}
return sum + c
}
func kahanSumInc(inc, sum, c float64) (newSum, newC float64) {
t := sum + inc
// Using Neumaier improvement, swap if next term larger than sum.
if math.Abs(sum) >= math.Abs(inc) {
c += (sum - t) + inc
} else {
c += (inc - t) + sum
}
return t, c
}
// linearRegression performs a least-square linear regression analysis on the
// provided SamplePairs. It returns the slope, and the intercept value at the
// provided time.
func linearRegression(samples []FPoint, interceptTime int64) (slope, intercept float64) {
var (
n float64
sumX, cX float64
sumY, cY float64
sumXY, cXY float64
sumX2, cX2 float64
initY float64
constY bool
)
initY = samples[0].F
constY = true
for i, sample := range samples {
// Set constY to false if any new y values are encountered.
if constY && i > 0 && sample.F != initY {
constY = false
}
n += 1.0
x := float64(sample.T-interceptTime) / 1e3
sumX, cX = kahanSumInc(x, sumX, cX)
sumY, cY = kahanSumInc(sample.F, sumY, cY)
sumXY, cXY = kahanSumInc(x*sample.F, sumXY, cXY)
sumX2, cX2 = kahanSumInc(x*x, sumX2, cX2)
}
if constY {
if math.IsInf(initY, 0) {
return math.NaN(), math.NaN()
}
return 0, initY
}
sumX += cX
sumY += cY
sumXY += cXY
sumX2 += cX2
covXY := sumXY - sumX*sumY/n
varX := sumX2 - sumX*sumX/n
slope = covXY / varX
intercept = sumY/n - slope*sumX/n
return slope, intercept
}
// === deriv(node parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcDeriv(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
samples := vals[0].(Matrix)[0]
// No sense in trying to compute a derivative without at least two points.
// Drop this Vector element.
if len(samples.Floats) < 2 {
return enh.Out, nil
}
// We pass in an arbitrary timestamp that is near the values in use
// to avoid floating point accuracy issues, see
// https://github.com/prometheus/prometheus/issues/2674
slope, _ := linearRegression(samples.Floats, samples.Floats[0].T)
return append(enh.Out, Sample{F: slope}), nil
}
// === predict_linear(node parser.ValueTypeMatrix, k parser.ValueTypeScalar) (Vector, Annotations) ===
func funcPredictLinear(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
samples := vals[0].(Matrix)[0]
duration := vals[1].(Vector)[0].F
// No sense in trying to predict anything without at least two points.
// Drop this Vector element.
if len(samples.Floats) < 2 {
return enh.Out, nil
}
slope, intercept := linearRegression(samples.Floats, enh.Ts)
return append(enh.Out, Sample{F: slope*duration + intercept}), nil
}
// === histogram_count(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcHistogramCount(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
inVec := vals[0].(Vector)
for _, sample := range inVec {
// Skip non-histogram samples.
if sample.H == nil {
continue
}
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(sample.Metric),
F: sample.H.Count,
})
}
return enh.Out, nil
}
// === histogram_sum(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcHistogramSum(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
inVec := vals[0].(Vector)
for _, sample := range inVec {
// Skip non-histogram samples.
if sample.H == nil {
continue
}
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(sample.Metric),
F: sample.H.Sum,
})
}
return enh.Out, nil
}
// === histogram_stddev(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcHistogramStdDev(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
inVec := vals[0].(Vector)
for _, sample := range inVec {
// Skip non-histogram samples.
if sample.H == nil {
continue
}
mean := sample.H.Sum / sample.H.Count
var variance, cVariance float64
it := sample.H.AllBucketIterator()
for it.Next() {
bucket := it.At()
var val float64
if bucket.Lower <= 0 && 0 <= bucket.Upper {
val = 0
} else {
val = math.Sqrt(bucket.Upper * bucket.Lower)
}
delta := val - mean
variance, cVariance = kahanSumInc(bucket.Count*delta*delta, variance, cVariance)
}
variance += cVariance
variance /= sample.H.Count
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(sample.Metric),
F: math.Sqrt(variance),
})
}
return enh.Out, nil
}
// === histogram_stdvar(Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcHistogramStdVar(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
inVec := vals[0].(Vector)
for _, sample := range inVec {
// Skip non-histogram samples.
if sample.H == nil {
continue
}
mean := sample.H.Sum / sample.H.Count
var variance, cVariance float64
it := sample.H.AllBucketIterator()
for it.Next() {
bucket := it.At()
var val float64
if bucket.Lower <= 0 && 0 <= bucket.Upper {
val = 0
} else {
val = math.Sqrt(bucket.Upper * bucket.Lower)
}
delta := val - mean
variance, cVariance = kahanSumInc(bucket.Count*delta*delta, variance, cVariance)
}
variance += cVariance
variance /= sample.H.Count
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(sample.Metric),
F: variance,
})
}
return enh.Out, nil
}
// === histogram_fraction(lower, upper parser.ValueTypeScalar, Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcHistogramFraction(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
lower := vals[0].(Vector)[0].F
upper := vals[1].(Vector)[0].F
inVec := vals[2].(Vector)
for _, sample := range inVec {
// Skip non-histogram samples.
if sample.H == nil {
continue
}
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(sample.Metric),
F: histogramFraction(lower, upper, sample.H),
})
}
return enh.Out, nil
}
// === histogram_quantile(k parser.ValueTypeScalar, Vector parser.ValueTypeVector) (Vector, Annotations) ===
func funcHistogramQuantile(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
q := vals[0].(Vector)[0].F
inVec := vals[1].(Vector)
annos := annotations.Annotations{}
if math.IsNaN(q) || q < 0 || q > 1 {
annos.Add(annotations.NewInvalidQuantileWarning(q, args[0].PositionRange()))
}
if enh.signatureToMetricWithBuckets == nil {
enh.signatureToMetricWithBuckets = map[string]*metricWithBuckets{}
} else {
for _, v := range enh.signatureToMetricWithBuckets {
v.buckets = v.buckets[:0]
}
}
var histogramSamples []Sample
for _, sample := range inVec {
// We are only looking for conventional buckets here. Remember
// the histograms for later treatment.
if sample.H != nil {
histogramSamples = append(histogramSamples, sample)
continue
}
upperBound, err := strconv.ParseFloat(
sample.Metric.Get(model.BucketLabel), 64,
)
if err != nil {
annos.Add(annotations.NewBadBucketLabelWarning(sample.Metric.Get(labels.MetricName), sample.Metric.Get(model.BucketLabel), args[1].PositionRange()))
continue
}
enh.lblBuf = sample.Metric.BytesWithoutLabels(enh.lblBuf, labels.BucketLabel)
mb, ok := enh.signatureToMetricWithBuckets[string(enh.lblBuf)]
if !ok {
sample.Metric = labels.NewBuilder(sample.Metric).
Del(excludedLabels...).
Labels()
mb = &metricWithBuckets{sample.Metric, nil}
enh.signatureToMetricWithBuckets[string(enh.lblBuf)] = mb
}
mb.buckets = append(mb.buckets, bucket{upperBound, sample.F})
}
// Now deal with the histograms.
for _, sample := range histogramSamples {
// We have to reconstruct the exact same signature as above for
// a conventional histogram, just ignoring any le label.
enh.lblBuf = sample.Metric.Bytes(enh.lblBuf)
if mb, ok := enh.signatureToMetricWithBuckets[string(enh.lblBuf)]; ok && len(mb.buckets) > 0 {
// At this data point, we have conventional histogram
// buckets and a native histogram with the same name and
// labels. Do not evaluate anything.
annos.Add(annotations.NewMixedClassicNativeHistogramsWarning(sample.Metric.Get(labels.MetricName), args[1].PositionRange()))
delete(enh.signatureToMetricWithBuckets, string(enh.lblBuf))
continue
}
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(sample.Metric),
F: histogramQuantile(q, sample.H),
})
}
for _, mb := range enh.signatureToMetricWithBuckets {
if len(mb.buckets) > 0 {
res, forcedMonotonicity := bucketQuantile(q, mb.buckets)
enh.Out = append(enh.Out, Sample{
Metric: mb.metric,
F: res,
})
if forcedMonotonicity {
annos.Add(annotations.NewHistogramQuantileForcedMonotonicityInfo(mb.metric.Get(labels.MetricName), args[1].PositionRange()))
}
}
}
return enh.Out, annos
}
// === resets(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcResets(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
floats := vals[0].(Matrix)[0].Floats
histograms := vals[0].(Matrix)[0].Histograms
resets := 0
if len(floats) > 1 {
prev := floats[0].F
for _, sample := range floats[1:] {
current := sample.F
if current < prev {
resets++
}
prev = current
}
}
if len(histograms) > 1 {
prev := histograms[0].H
for _, sample := range histograms[1:] {
current := sample.H
if current.DetectReset(prev) {
resets++
}
prev = current
}
}
return append(enh.Out, Sample{F: float64(resets)}), nil
}
// === changes(Matrix parser.ValueTypeMatrix) (Vector, Annotations) ===
func funcChanges(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
floats := vals[0].(Matrix)[0].Floats
changes := 0
if len(floats) == 0 {
// TODO(beorn7): Only histogram values, still need to add support.
return enh.Out, nil
}
prev := floats[0].F
for _, sample := range floats[1:] {
current := sample.F
if current != prev && !(math.IsNaN(current) && math.IsNaN(prev)) {
changes++
}
prev = current
}
return append(enh.Out, Sample{F: float64(changes)}), nil
}
// === label_replace(Vector parser.ValueTypeVector, dst_label, replacement, src_labelname, regex parser.ValueTypeString) (Vector, Annotations) ===
func funcLabelReplace(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
var (
vector = vals[0].(Vector)
dst = stringFromArg(args[1])
repl = stringFromArg(args[2])
src = stringFromArg(args[3])
regexStr = stringFromArg(args[4])
)
if enh.regex == nil {
var err error
enh.regex, err = regexp.Compile("^(?:" + regexStr + ")$")
if err != nil {
panic(fmt.Errorf("invalid regular expression in label_replace(): %s", regexStr))
}
if !model.LabelNameRE.MatchString(dst) {
panic(fmt.Errorf("invalid destination label name in label_replace(): %s", dst))
}
enh.Dmn = make(map[uint64]labels.Labels, len(enh.Out))
}
for _, el := range vector {
h := el.Metric.Hash()
var outMetric labels.Labels
if l, ok := enh.Dmn[h]; ok {
outMetric = l
} else {
srcVal := el.Metric.Get(src)
indexes := enh.regex.FindStringSubmatchIndex(srcVal)
if indexes == nil {
// If there is no match, no replacement should take place.
outMetric = el.Metric
enh.Dmn[h] = outMetric
} else {
res := enh.regex.ExpandString([]byte{}, repl, srcVal, indexes)
lb := labels.NewBuilder(el.Metric).Del(dst)
if len(res) > 0 {
lb.Set(dst, string(res))
}
outMetric = lb.Labels()
enh.Dmn[h] = outMetric
}
}
enh.Out = append(enh.Out, Sample{
Metric: outMetric,
F: el.F,
H: el.H,
})
}
return enh.Out, nil
}
// === Vector(s Scalar) (Vector, Annotations) ===
func funcVector(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return append(enh.Out,
Sample{
Metric: labels.Labels{},
F: vals[0].(Vector)[0].F,
}), nil
}
// === label_join(vector model.ValVector, dest_labelname, separator, src_labelname...) (Vector, Annotations) ===
func funcLabelJoin(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
var (
vector = vals[0].(Vector)
dst = stringFromArg(args[1])
sep = stringFromArg(args[2])
srcLabels = make([]string, len(args)-3)
)
if enh.Dmn == nil {
enh.Dmn = make(map[uint64]labels.Labels, len(enh.Out))
}
for i := 3; i < len(args); i++ {
src := stringFromArg(args[i])
if !model.LabelName(src).IsValid() {
panic(fmt.Errorf("invalid source label name in label_join(): %s", src))
}
srcLabels[i-3] = src
}
if !model.LabelName(dst).IsValid() {
panic(fmt.Errorf("invalid destination label name in label_join(): %s", dst))
}
srcVals := make([]string, len(srcLabels))
for _, el := range vector {
h := el.Metric.Hash()
var outMetric labels.Labels
if l, ok := enh.Dmn[h]; ok {
outMetric = l
} else {
for i, src := range srcLabels {
srcVals[i] = el.Metric.Get(src)
}
lb := labels.NewBuilder(el.Metric)
strval := strings.Join(srcVals, sep)
if strval == "" {
lb.Del(dst)
} else {
lb.Set(dst, strval)
}
outMetric = lb.Labels()
enh.Dmn[h] = outMetric
}
enh.Out = append(enh.Out, Sample{
Metric: outMetric,
F: el.F,
H: el.H,
})
}
return enh.Out, nil
}
// Common code for date related functions.
func dateWrapper(vals []parser.Value, enh *EvalNodeHelper, f func(time.Time) float64) Vector {
if len(vals) == 0 {
return append(enh.Out,
Sample{
Metric: labels.Labels{},
F: f(time.Unix(enh.Ts/1000, 0).UTC()),
})
}
for _, el := range vals[0].(Vector) {
t := time.Unix(int64(el.F), 0).UTC()
enh.Out = append(enh.Out, Sample{
Metric: enh.DropMetricName(el.Metric),
F: f(t),
})
}
return enh.Out
}
// === days_in_month(v Vector) Scalar ===
func funcDaysInMonth(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(32 - time.Date(t.Year(), t.Month(), 32, 0, 0, 0, 0, time.UTC).Day())
}), nil
}
// === day_of_month(v Vector) Scalar ===
func funcDayOfMonth(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(t.Day())
}), nil
}
// === day_of_week(v Vector) Scalar ===
func funcDayOfWeek(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(t.Weekday())
}), nil
}
// === day_of_year(v Vector) Scalar ===
func funcDayOfYear(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(t.YearDay())
}), nil
}
// === hour(v Vector) Scalar ===
func funcHour(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(t.Hour())
}), nil
}
// === minute(v Vector) Scalar ===
func funcMinute(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(t.Minute())
}), nil
}
// === month(v Vector) Scalar ===
func funcMonth(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(t.Month())
}), nil
}
// === year(v Vector) Scalar ===
func funcYear(vals []parser.Value, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations) {
return dateWrapper(vals, enh, func(t time.Time) float64 {
return float64(t.Year())
}), nil
}
// FunctionCalls is a list of all functions supported by PromQL, including their types.
var FunctionCalls = map[string]FunctionCall{
"abs": funcAbs,
"absent": funcAbsent,
"absent_over_time": funcAbsentOverTime,
"acos": funcAcos,
"acosh": funcAcosh,
"asin": funcAsin,
"asinh": funcAsinh,
"atan": funcAtan,
"atanh": funcAtanh,
"avg_over_time": funcAvgOverTime,
"ceil": funcCeil,
"changes": funcChanges,
"clamp": funcClamp,
"clamp_max": funcClampMax,
"clamp_min": funcClampMin,
"cos": funcCos,
"cosh": funcCosh,
"count_over_time": funcCountOverTime,
"days_in_month": funcDaysInMonth,
"day_of_month": funcDayOfMonth,
"day_of_week": funcDayOfWeek,
"day_of_year": funcDayOfYear,
"deg": funcDeg,
"delta": funcDelta,
"deriv": funcDeriv,
"exp": funcExp,
"floor": funcFloor,
"histogram_count": funcHistogramCount,
"histogram_fraction": funcHistogramFraction,
"histogram_quantile": funcHistogramQuantile,
"histogram_sum": funcHistogramSum,
"histogram_stddev": funcHistogramStdDev,
"histogram_stdvar": funcHistogramStdVar,
"holt_winters": funcHoltWinters,
"hour": funcHour,
"idelta": funcIdelta,
"increase": funcIncrease,
"irate": funcIrate,
"label_replace": funcLabelReplace,
"label_join": funcLabelJoin,
"ln": funcLn,
"log10": funcLog10,
"log2": funcLog2,
"last_over_time": funcLastOverTime,
"max_over_time": funcMaxOverTime,
"min_over_time": funcMinOverTime,
"minute": funcMinute,
"month": funcMonth,
"pi": funcPi,
"predict_linear": funcPredictLinear,
"present_over_time": funcPresentOverTime,
"quantile_over_time": funcQuantileOverTime,
"rad": funcRad,
"rate": funcRate,
"resets": funcResets,
"round": funcRound,
"scalar": funcScalar,
"sgn": funcSgn,
"sin": funcSin,
"sinh": funcSinh,
"sort": funcSort,
"sort_desc": funcSortDesc,
"sqrt": funcSqrt,
"stddev_over_time": funcStddevOverTime,
"stdvar_over_time": funcStdvarOverTime,
"sum_over_time": funcSumOverTime,
"tan": funcTan,
"tanh": funcTanh,
"time": funcTime,
"timestamp": funcTimestamp,
"vector": funcVector,
"year": funcYear,
}
// AtModifierUnsafeFunctions are the functions whose result
// can vary if evaluation time is changed when the arguments are
// step invariant. It also includes functions that use the timestamps
// of the passed instant vector argument to calculate a result since
// that can also change with change in eval time.
var AtModifierUnsafeFunctions = map[string]struct{}{
// Step invariant functions.
"days_in_month": {}, "day_of_month": {}, "day_of_week": {}, "day_of_year": {},
"hour": {}, "minute": {}, "month": {}, "year": {},
"predict_linear": {}, "time": {},
// Uses timestamp of the argument for the result,
// hence unsafe to use with @ modifier.
"timestamp": {},
}
type vectorByValueHeap Vector
func (s vectorByValueHeap) Len() int {
return len(s)
}
func (s vectorByValueHeap) Less(i, j int) bool {
// We compare histograms based on their sum of observations.
// TODO(beorn7): Is that what we want?
vi, vj := s[i].F, s[j].F
if s[i].H != nil {
vi = s[i].H.Sum
}
if s[j].H != nil {
vj = s[j].H.Sum
}
if math.IsNaN(vi) {
return true
}
return vi < vj
}
func (s vectorByValueHeap) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s *vectorByValueHeap) Push(x interface{}) {
*s = append(*s, *(x.(*Sample)))
}
func (s *vectorByValueHeap) Pop() interface{} {
old := *s
n := len(old)
el := old[n-1]
*s = old[0 : n-1]
return el
}
type vectorByReverseValueHeap Vector
func (s vectorByReverseValueHeap) Len() int {
return len(s)
}
func (s vectorByReverseValueHeap) Less(i, j int) bool {
// We compare histograms based on their sum of observations.
// TODO(beorn7): Is that what we want?
vi, vj := s[i].F, s[j].F
if s[i].H != nil {
vi = s[i].H.Sum
}
if s[j].H != nil {
vj = s[j].H.Sum
}
if math.IsNaN(vi) {
return true
}
return vi > vj
}
func (s vectorByReverseValueHeap) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s *vectorByReverseValueHeap) Push(x interface{}) {
*s = append(*s, *(x.(*Sample)))
}
func (s *vectorByReverseValueHeap) Pop() interface{} {
old := *s
n := len(old)
el := old[n-1]
*s = old[0 : n-1]
return el
}
// createLabelsForAbsentFunction returns the labels that are uniquely and exactly matched
// in a given expression. It is used in the absent functions.
func createLabelsForAbsentFunction(expr parser.Expr) labels.Labels {
b := labels.NewBuilder(labels.EmptyLabels())
var lm []*labels.Matcher
switch n := expr.(type) {
case *parser.VectorSelector:
lm = n.LabelMatchers
case *parser.MatrixSelector:
lm = n.VectorSelector.(*parser.VectorSelector).LabelMatchers
default:
return labels.EmptyLabels()
}
// The 'has' map implements backwards-compatibility for historic behaviour:
// e.g. in `absent(x{job="a",job="b",foo="bar"})` then `job` is removed from the output.
// Note this gives arguably wrong behaviour for `absent(x{job="a",job="a",foo="bar"})`.
has := make(map[string]bool, len(lm))
for _, ma := range lm {
if ma.Name == labels.MetricName {
continue
}
if ma.Type == labels.MatchEqual && !has[ma.Name] {
b.Set(ma.Name, ma.Value)
has[ma.Name] = true
} else {
b.Del(ma.Name)
}
}
return b.Labels()
}
func stringFromArg(e parser.Expr) string {
tmp := unwrapStepInvariantExpr(e) // Unwrap StepInvariant
unwrapParenExpr(&tmp) // Optionally unwrap ParenExpr
return tmp.(*parser.StringLiteral).Val
}