aggregators

Documentation

Overview

Package aggregators contains aggregator factory methods. The aggregators package must not depend on any other scotty packages except for tsdb.

Index

• Variables
• func Names() (result []string)
• func New(start, end float64, aggregator *Aggregator, downSample float64, ...) tsdb.Aggregator
• type Aggregator
  • func ByName(aggregatorName string) (*Aggregator, bool)
• type FillPolicy
  • func ByFillPolicyName(fillPolicyName string) (FillPolicy, bool)
• type RateSpec

Variables

var (
	Avg = &Aggregator{
		aggListCreater: func(size int) aggregatorListType {
			return make(averageListType, size)
		},
		updaterCreater: kLinearInterpolation,
	}
	Count = &Aggregator{
		aggListCreater: func(size int) aggregatorListType {
			return make(countListType, size)
		},
		updaterCreater: kZero,
	}
	Max = &Aggregator{
		aggListCreater: func(size int) aggregatorListType {
			return make(maxListType, size)
		},
		updaterCreater: kLinearInterpolation,
	}
	Min = &Aggregator{
		aggListCreater: func(size int) aggregatorListType {
			return make(minListType, size)
		},
		updaterCreater: kLinearInterpolation,
	}
	Sum = &Aggregator{
		aggListCreater: func(size int) aggregatorListType {
			return make(sumListType, size)
		},
		updaterCreater: kLinearInterpolation,
	}
)

Functions

func Names

func Names() (result []string)

Names returns all the aggregator names.

func New

func New(
	start, end float64,
	aggregator *Aggregator,
	downSample float64,
	downSampleAggregator *Aggregator,
	fillPolicy FillPolicy,
	optionalRateSpec *RateSpec) tsdb.Aggregator

downSample is the down sample time in seconds. New treats downSample values less than 1.0 as 1.0

fillPolicy is the FillPolicy to use when downsampling.

optionalRateSpec is the TSDB rate specification. If non-nil, the Aggregate method reports rate of change per second in aggregated values instead of the actual aggregated values.

Types

type Aggregator

type Aggregator struct {
	// contains filtered or unexported fields
}

Aggregator instances correspond to OpenTSDB aggregators such as sum, avg, count, max, etc.

func ByName

func ByName(aggregatorName string) (*Aggregator, bool)

ByName returns the aggregator with given name or nil, false if no aggregator matches given name

type FillPolicy

type FillPolicy int

FillPolicy describes how to handle missing values after downsampling

const (
	// None is the default. Do not emit missing values.
	None FillPolicy = iota
	// NaN behaves the same as None for now
	NaN
	// Null behaves the same as None for now
	Null
	// Zero means emit zero when no values are present in a downsample range
	Zero
)

func ByFillPolicyName

func ByFillPolicyName(fillPolicyName string) (FillPolicy, bool)

ByFillPolicyName returns the fill policy with given name or None, false if no fill policy matches given name

type RateSpec

type RateSpec struct {
	// True if metric is a counter. Counter metrics are ever increasing.
	Counter bool
	// If Counter is true, the maximum value of the counter.
	// Used to correctly determine rate of change if counter rolls over
	CounterMax float64
	// If Counter is true, the maximum expected rate of change. If rate
	// of change exceeds this, we assume counter rolled over because of
	// a restart.
	ResetValue float64
}

RateSpec is the rate of change specification for ever increasing metrics.