github.com/influxdata/influxdb/v2@v2.7.6/influxql/query/functions.gen.go

// Generated by tmpl
// https://github.com/benbjohnson/tmpl
//
// DO NOT EDIT!
// Source: functions.gen.go.tmpl

package query

import (
	"bytes"
	"encoding/binary"
	"math/rand"
	"sort"
	"time"

	"github.com/influxdata/influxdb/v2/pkg/estimator/hll"
)

// FloatPointAggregator aggregates points to produce a single point.
type FloatPointAggregator interface {
	AggregateFloat(p *FloatPoint)
}

// FloatBulkPointAggregator aggregates multiple points at a time.
type FloatBulkPointAggregator interface {
	AggregateFloatBulk(points []FloatPoint)
}

// FloatPointEmitter produces a single point from an aggregate.
type FloatPointEmitter interface {
	Emit() []FloatPoint
}

// FloatReduceFunc is the function called by a FloatPoint reducer.
type FloatReduceFunc func(prev *FloatPoint, curr *FloatPoint) (t int64, v float64, aux []interface{})

// FloatFuncReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type FloatFuncReducer struct {
	prev *FloatPoint
	fn   FloatReduceFunc
}

// NewFloatFuncReducer creates a new FloatFuncFloatReducer.
func NewFloatFuncReducer(fn FloatReduceFunc, prev *FloatPoint) *FloatFuncReducer {
	return &FloatFuncReducer{fn: fn, prev: prev}
}

// AggregateFloat takes a FloatPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *FloatFuncReducer) AggregateFloat(p *FloatPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &FloatPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateFloat.
func (r *FloatFuncReducer) Emit() []FloatPoint {
	return []FloatPoint{*r.prev}
}

// FloatReduceSliceFunc is the function called by a FloatPoint reducer.
type FloatReduceSliceFunc func(a []FloatPoint) []FloatPoint

// FloatSliceFuncReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type FloatSliceFuncReducer struct {
	points []FloatPoint
	fn     FloatReduceSliceFunc
}

// NewFloatSliceFuncReducer creates a new FloatSliceFuncReducer.
func NewFloatSliceFuncReducer(fn FloatReduceSliceFunc) *FloatSliceFuncReducer {
	return &FloatSliceFuncReducer{fn: fn}
}

// AggregateFloat copies the FloatPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *FloatSliceFuncReducer) AggregateFloat(p *FloatPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateFloatBulk performs a bulk copy of FloatPoints into the internal slice.
// This is a more efficient version of calling AggregateFloat on each point.
func (r *FloatSliceFuncReducer) AggregateFloatBulk(points []FloatPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *FloatSliceFuncReducer) Emit() []FloatPoint {
	return r.fn(r.points)
}

// FloatReduceIntegerFunc is the function called by a FloatPoint reducer.
type FloatReduceIntegerFunc func(prev *IntegerPoint, curr *FloatPoint) (t int64, v int64, aux []interface{})

// FloatFuncIntegerReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type FloatFuncIntegerReducer struct {
	prev *IntegerPoint
	fn   FloatReduceIntegerFunc
}

// NewFloatFuncIntegerReducer creates a new FloatFuncIntegerReducer.
func NewFloatFuncIntegerReducer(fn FloatReduceIntegerFunc, prev *IntegerPoint) *FloatFuncIntegerReducer {
	return &FloatFuncIntegerReducer{fn: fn, prev: prev}
}

// AggregateFloat takes a FloatPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *FloatFuncIntegerReducer) AggregateFloat(p *FloatPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &IntegerPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateFloat.
func (r *FloatFuncIntegerReducer) Emit() []IntegerPoint {
	return []IntegerPoint{*r.prev}
}

// FloatReduceIntegerSliceFunc is the function called by a FloatPoint reducer.
type FloatReduceIntegerSliceFunc func(a []FloatPoint) []IntegerPoint

// FloatSliceFuncIntegerReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type FloatSliceFuncIntegerReducer struct {
	points []FloatPoint
	fn     FloatReduceIntegerSliceFunc
}

// NewFloatSliceFuncIntegerReducer creates a new FloatSliceFuncIntegerReducer.
func NewFloatSliceFuncIntegerReducer(fn FloatReduceIntegerSliceFunc) *FloatSliceFuncIntegerReducer {
	return &FloatSliceFuncIntegerReducer{fn: fn}
}

// AggregateFloat copies the FloatPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *FloatSliceFuncIntegerReducer) AggregateFloat(p *FloatPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateFloatBulk performs a bulk copy of FloatPoints into the internal slice.
// This is a more efficient version of calling AggregateFloat on each point.
func (r *FloatSliceFuncIntegerReducer) AggregateFloatBulk(points []FloatPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *FloatSliceFuncIntegerReducer) Emit() []IntegerPoint {
	return r.fn(r.points)
}

// FloatReduceUnsignedFunc is the function called by a FloatPoint reducer.
type FloatReduceUnsignedFunc func(prev *UnsignedPoint, curr *FloatPoint) (t int64, v uint64, aux []interface{})

// FloatFuncUnsignedReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type FloatFuncUnsignedReducer struct {
	prev *UnsignedPoint
	fn   FloatReduceUnsignedFunc
}

// NewFloatFuncUnsignedReducer creates a new FloatFuncUnsignedReducer.
func NewFloatFuncUnsignedReducer(fn FloatReduceUnsignedFunc, prev *UnsignedPoint) *FloatFuncUnsignedReducer {
	return &FloatFuncUnsignedReducer{fn: fn, prev: prev}
}

// AggregateFloat takes a FloatPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *FloatFuncUnsignedReducer) AggregateFloat(p *FloatPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &UnsignedPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateFloat.
func (r *FloatFuncUnsignedReducer) Emit() []UnsignedPoint {
	return []UnsignedPoint{*r.prev}
}

// FloatReduceUnsignedSliceFunc is the function called by a FloatPoint reducer.
type FloatReduceUnsignedSliceFunc func(a []FloatPoint) []UnsignedPoint

// FloatSliceFuncUnsignedReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type FloatSliceFuncUnsignedReducer struct {
	points []FloatPoint
	fn     FloatReduceUnsignedSliceFunc
}

// NewFloatSliceFuncUnsignedReducer creates a new FloatSliceFuncUnsignedReducer.
func NewFloatSliceFuncUnsignedReducer(fn FloatReduceUnsignedSliceFunc) *FloatSliceFuncUnsignedReducer {
	return &FloatSliceFuncUnsignedReducer{fn: fn}
}

// AggregateFloat copies the FloatPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *FloatSliceFuncUnsignedReducer) AggregateFloat(p *FloatPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateFloatBulk performs a bulk copy of FloatPoints into the internal slice.
// This is a more efficient version of calling AggregateFloat on each point.
func (r *FloatSliceFuncUnsignedReducer) AggregateFloatBulk(points []FloatPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *FloatSliceFuncUnsignedReducer) Emit() []UnsignedPoint {
	return r.fn(r.points)
}

// FloatReduceStringFunc is the function called by a FloatPoint reducer.
type FloatReduceStringFunc func(prev *StringPoint, curr *FloatPoint) (t int64, v string, aux []interface{})

// FloatFuncStringReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type FloatFuncStringReducer struct {
	prev *StringPoint
	fn   FloatReduceStringFunc
}

// NewFloatFuncStringReducer creates a new FloatFuncStringReducer.
func NewFloatFuncStringReducer(fn FloatReduceStringFunc, prev *StringPoint) *FloatFuncStringReducer {
	return &FloatFuncStringReducer{fn: fn, prev: prev}
}

// AggregateFloat takes a FloatPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *FloatFuncStringReducer) AggregateFloat(p *FloatPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &StringPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateFloat.
func (r *FloatFuncStringReducer) Emit() []StringPoint {
	return []StringPoint{*r.prev}
}

// FloatReduceStringSliceFunc is the function called by a FloatPoint reducer.
type FloatReduceStringSliceFunc func(a []FloatPoint) []StringPoint

// FloatSliceFuncStringReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type FloatSliceFuncStringReducer struct {
	points []FloatPoint
	fn     FloatReduceStringSliceFunc
}

// NewFloatSliceFuncStringReducer creates a new FloatSliceFuncStringReducer.
func NewFloatSliceFuncStringReducer(fn FloatReduceStringSliceFunc) *FloatSliceFuncStringReducer {
	return &FloatSliceFuncStringReducer{fn: fn}
}

// AggregateFloat copies the FloatPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *FloatSliceFuncStringReducer) AggregateFloat(p *FloatPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateFloatBulk performs a bulk copy of FloatPoints into the internal slice.
// This is a more efficient version of calling AggregateFloat on each point.
func (r *FloatSliceFuncStringReducer) AggregateFloatBulk(points []FloatPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *FloatSliceFuncStringReducer) Emit() []StringPoint {
	return r.fn(r.points)
}

// FloatReduceBooleanFunc is the function called by a FloatPoint reducer.
type FloatReduceBooleanFunc func(prev *BooleanPoint, curr *FloatPoint) (t int64, v bool, aux []interface{})

// FloatFuncBooleanReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type FloatFuncBooleanReducer struct {
	prev *BooleanPoint
	fn   FloatReduceBooleanFunc
}

// NewFloatFuncBooleanReducer creates a new FloatFuncBooleanReducer.
func NewFloatFuncBooleanReducer(fn FloatReduceBooleanFunc, prev *BooleanPoint) *FloatFuncBooleanReducer {
	return &FloatFuncBooleanReducer{fn: fn, prev: prev}
}

// AggregateFloat takes a FloatPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *FloatFuncBooleanReducer) AggregateFloat(p *FloatPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &BooleanPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateFloat.
func (r *FloatFuncBooleanReducer) Emit() []BooleanPoint {
	return []BooleanPoint{*r.prev}
}

// FloatReduceBooleanSliceFunc is the function called by a FloatPoint reducer.
type FloatReduceBooleanSliceFunc func(a []FloatPoint) []BooleanPoint

// FloatSliceFuncBooleanReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type FloatSliceFuncBooleanReducer struct {
	points []FloatPoint
	fn     FloatReduceBooleanSliceFunc
}

// NewFloatSliceFuncBooleanReducer creates a new FloatSliceFuncBooleanReducer.
func NewFloatSliceFuncBooleanReducer(fn FloatReduceBooleanSliceFunc) *FloatSliceFuncBooleanReducer {
	return &FloatSliceFuncBooleanReducer{fn: fn}
}

// AggregateFloat copies the FloatPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *FloatSliceFuncBooleanReducer) AggregateFloat(p *FloatPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateFloatBulk performs a bulk copy of FloatPoints into the internal slice.
// This is a more efficient version of calling AggregateFloat on each point.
func (r *FloatSliceFuncBooleanReducer) AggregateFloatBulk(points []FloatPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *FloatSliceFuncBooleanReducer) Emit() []BooleanPoint {
	return r.fn(r.points)
}

// FloatSumHllReducer returns the HLL sketch for a series, in string form
type FloatSumHllReducer struct {
	plus *hll.Plus
}

// func NewFloatSumHllReducer creates a new FloatSumHllReducer
func NewFloatSumHllReducer() *FloatSumHllReducer {
	return &FloatSumHllReducer{plus: hll.NewDefaultPlus()}
}

// AggregateFloat aggregates a point into the reducer.
func (r *FloatSumHllReducer) AggregateFloat(p *FloatPoint) {

	buf := new(bytes.Buffer)
	binary.Write(buf, binary.BigEndian, p.Value)
	b := buf.Bytes()

	r.plus.Add(b)
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *FloatSumHllReducer) Emit() []StringPoint {
	return []StringPoint{
		marshalPlus(r.plus, nil),
	}
}

// FloatDistinctReducer returns the distinct points in a series.
type FloatDistinctReducer struct {
	m map[float64]FloatPoint
}

// NewFloatDistinctReducer creates a new FloatDistinctReducer.
func NewFloatDistinctReducer() *FloatDistinctReducer {
	return &FloatDistinctReducer{m: make(map[float64]FloatPoint)}
}

// AggregateFloat aggregates a point into the reducer.
func (r *FloatDistinctReducer) AggregateFloat(p *FloatPoint) {
	if _, ok := r.m[p.Value]; !ok {
		r.m[p.Value] = *p
	}
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *FloatDistinctReducer) Emit() []FloatPoint {
	points := make([]FloatPoint, 0, len(r.m))
	for _, p := range r.m {
		points = append(points, FloatPoint{Time: p.Time, Value: p.Value})
	}
	sort.Sort(floatPoints(points))
	return points
}

// FloatElapsedReducer calculates the elapsed of the aggregated points.
type FloatElapsedReducer struct {
	unitConversion int64
	prev           FloatPoint
	curr           FloatPoint
}

// NewFloatElapsedReducer creates a new FloatElapsedReducer.
func NewFloatElapsedReducer(interval Interval) *FloatElapsedReducer {
	return &FloatElapsedReducer{
		unitConversion: int64(interval.Duration),
		prev:           FloatPoint{Nil: true},
		curr:           FloatPoint{Nil: true},
	}
}

// AggregateFloat aggregates a point into the reducer and updates the current window.
func (r *FloatElapsedReducer) AggregateFloat(p *FloatPoint) {
	r.prev = r.curr
	r.curr = *p
}

// Emit emits the elapsed of the reducer at the current point.
func (r *FloatElapsedReducer) Emit() []IntegerPoint {
	if !r.prev.Nil {
		elapsed := (r.curr.Time - r.prev.Time) / r.unitConversion
		return []IntegerPoint{
			{Time: r.curr.Time, Value: elapsed},
		}
	}
	return nil
}

// FloatSampleReducer implements a reservoir sampling to calculate a random subset of points
type FloatSampleReducer struct {
	count int        // how many points we've iterated over
	rng   *rand.Rand // random number generator for each reducer

	points floatPoints // the reservoir
}

// NewFloatSampleReducer creates a new FloatSampleReducer
func NewFloatSampleReducer(size int) *FloatSampleReducer {
	return &FloatSampleReducer{
		rng:    rand.New(rand.NewSource(time.Now().UnixNano())), // seed with current time as suggested by https://golang.org/pkg/math/rand/
		points: make(floatPoints, size),
	}
}

// AggregateFloat aggregates a point into the reducer.
func (r *FloatSampleReducer) AggregateFloat(p *FloatPoint) {
	r.count++
	// Fill the reservoir with the first n points
	if r.count-1 < len(r.points) {
		p.CopyTo(&r.points[r.count-1])
		return
	}

	// Generate a random integer between 1 and the count and
	// if that number is less than the length of the slice
	// replace the point at that index rnd with p.
	rnd := r.rng.Intn(r.count)
	if rnd < len(r.points) {
		p.CopyTo(&r.points[rnd])
	}
}

// Emit emits the reservoir sample as many points.
func (r *FloatSampleReducer) Emit() []FloatPoint {
	min := len(r.points)
	if r.count < min {
		min = r.count
	}
	pts := r.points[:min]
	sort.Sort(pts)
	return pts
}

// IntegerPointAggregator aggregates points to produce a single point.
type IntegerPointAggregator interface {
	AggregateInteger(p *IntegerPoint)
}

// IntegerBulkPointAggregator aggregates multiple points at a time.
type IntegerBulkPointAggregator interface {
	AggregateIntegerBulk(points []IntegerPoint)
}

// IntegerPointEmitter produces a single point from an aggregate.
type IntegerPointEmitter interface {
	Emit() []IntegerPoint
}

// IntegerReduceFloatFunc is the function called by a IntegerPoint reducer.
type IntegerReduceFloatFunc func(prev *FloatPoint, curr *IntegerPoint) (t int64, v float64, aux []interface{})

// IntegerFuncFloatReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type IntegerFuncFloatReducer struct {
	prev *FloatPoint
	fn   IntegerReduceFloatFunc
}

// NewIntegerFuncFloatReducer creates a new IntegerFuncFloatReducer.
func NewIntegerFuncFloatReducer(fn IntegerReduceFloatFunc, prev *FloatPoint) *IntegerFuncFloatReducer {
	return &IntegerFuncFloatReducer{fn: fn, prev: prev}
}

// AggregateInteger takes a IntegerPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *IntegerFuncFloatReducer) AggregateInteger(p *IntegerPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &FloatPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateInteger.
func (r *IntegerFuncFloatReducer) Emit() []FloatPoint {
	return []FloatPoint{*r.prev}
}

// IntegerReduceFloatSliceFunc is the function called by a IntegerPoint reducer.
type IntegerReduceFloatSliceFunc func(a []IntegerPoint) []FloatPoint

// IntegerSliceFuncFloatReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type IntegerSliceFuncFloatReducer struct {
	points []IntegerPoint
	fn     IntegerReduceFloatSliceFunc
}

// NewIntegerSliceFuncFloatReducer creates a new IntegerSliceFuncFloatReducer.
func NewIntegerSliceFuncFloatReducer(fn IntegerReduceFloatSliceFunc) *IntegerSliceFuncFloatReducer {
	return &IntegerSliceFuncFloatReducer{fn: fn}
}

// AggregateInteger copies the IntegerPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *IntegerSliceFuncFloatReducer) AggregateInteger(p *IntegerPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateIntegerBulk performs a bulk copy of IntegerPoints into the internal slice.
// This is a more efficient version of calling AggregateInteger on each point.
func (r *IntegerSliceFuncFloatReducer) AggregateIntegerBulk(points []IntegerPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *IntegerSliceFuncFloatReducer) Emit() []FloatPoint {
	return r.fn(r.points)
}

// IntegerReduceFunc is the function called by a IntegerPoint reducer.
type IntegerReduceFunc func(prev *IntegerPoint, curr *IntegerPoint) (t int64, v int64, aux []interface{})

// IntegerFuncReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type IntegerFuncReducer struct {
	prev *IntegerPoint
	fn   IntegerReduceFunc
}

// NewIntegerFuncReducer creates a new IntegerFuncIntegerReducer.
func NewIntegerFuncReducer(fn IntegerReduceFunc, prev *IntegerPoint) *IntegerFuncReducer {
	return &IntegerFuncReducer{fn: fn, prev: prev}
}

// AggregateInteger takes a IntegerPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *IntegerFuncReducer) AggregateInteger(p *IntegerPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &IntegerPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateInteger.
func (r *IntegerFuncReducer) Emit() []IntegerPoint {
	return []IntegerPoint{*r.prev}
}

// IntegerReduceSliceFunc is the function called by a IntegerPoint reducer.
type IntegerReduceSliceFunc func(a []IntegerPoint) []IntegerPoint

// IntegerSliceFuncReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type IntegerSliceFuncReducer struct {
	points []IntegerPoint
	fn     IntegerReduceSliceFunc
}

// NewIntegerSliceFuncReducer creates a new IntegerSliceFuncReducer.
func NewIntegerSliceFuncReducer(fn IntegerReduceSliceFunc) *IntegerSliceFuncReducer {
	return &IntegerSliceFuncReducer{fn: fn}
}

// AggregateInteger copies the IntegerPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *IntegerSliceFuncReducer) AggregateInteger(p *IntegerPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateIntegerBulk performs a bulk copy of IntegerPoints into the internal slice.
// This is a more efficient version of calling AggregateInteger on each point.
func (r *IntegerSliceFuncReducer) AggregateIntegerBulk(points []IntegerPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *IntegerSliceFuncReducer) Emit() []IntegerPoint {
	return r.fn(r.points)
}

// IntegerReduceUnsignedFunc is the function called by a IntegerPoint reducer.
type IntegerReduceUnsignedFunc func(prev *UnsignedPoint, curr *IntegerPoint) (t int64, v uint64, aux []interface{})

// IntegerFuncUnsignedReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type IntegerFuncUnsignedReducer struct {
	prev *UnsignedPoint
	fn   IntegerReduceUnsignedFunc
}

// NewIntegerFuncUnsignedReducer creates a new IntegerFuncUnsignedReducer.
func NewIntegerFuncUnsignedReducer(fn IntegerReduceUnsignedFunc, prev *UnsignedPoint) *IntegerFuncUnsignedReducer {
	return &IntegerFuncUnsignedReducer{fn: fn, prev: prev}
}

// AggregateInteger takes a IntegerPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *IntegerFuncUnsignedReducer) AggregateInteger(p *IntegerPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &UnsignedPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateInteger.
func (r *IntegerFuncUnsignedReducer) Emit() []UnsignedPoint {
	return []UnsignedPoint{*r.prev}
}

// IntegerReduceUnsignedSliceFunc is the function called by a IntegerPoint reducer.
type IntegerReduceUnsignedSliceFunc func(a []IntegerPoint) []UnsignedPoint

// IntegerSliceFuncUnsignedReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type IntegerSliceFuncUnsignedReducer struct {
	points []IntegerPoint
	fn     IntegerReduceUnsignedSliceFunc
}

// NewIntegerSliceFuncUnsignedReducer creates a new IntegerSliceFuncUnsignedReducer.
func NewIntegerSliceFuncUnsignedReducer(fn IntegerReduceUnsignedSliceFunc) *IntegerSliceFuncUnsignedReducer {
	return &IntegerSliceFuncUnsignedReducer{fn: fn}
}

// AggregateInteger copies the IntegerPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *IntegerSliceFuncUnsignedReducer) AggregateInteger(p *IntegerPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateIntegerBulk performs a bulk copy of IntegerPoints into the internal slice.
// This is a more efficient version of calling AggregateInteger on each point.
func (r *IntegerSliceFuncUnsignedReducer) AggregateIntegerBulk(points []IntegerPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *IntegerSliceFuncUnsignedReducer) Emit() []UnsignedPoint {
	return r.fn(r.points)
}

// IntegerReduceStringFunc is the function called by a IntegerPoint reducer.
type IntegerReduceStringFunc func(prev *StringPoint, curr *IntegerPoint) (t int64, v string, aux []interface{})

// IntegerFuncStringReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type IntegerFuncStringReducer struct {
	prev *StringPoint
	fn   IntegerReduceStringFunc
}

// NewIntegerFuncStringReducer creates a new IntegerFuncStringReducer.
func NewIntegerFuncStringReducer(fn IntegerReduceStringFunc, prev *StringPoint) *IntegerFuncStringReducer {
	return &IntegerFuncStringReducer{fn: fn, prev: prev}
}

// AggregateInteger takes a IntegerPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *IntegerFuncStringReducer) AggregateInteger(p *IntegerPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &StringPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateInteger.
func (r *IntegerFuncStringReducer) Emit() []StringPoint {
	return []StringPoint{*r.prev}
}

// IntegerReduceStringSliceFunc is the function called by a IntegerPoint reducer.
type IntegerReduceStringSliceFunc func(a []IntegerPoint) []StringPoint

// IntegerSliceFuncStringReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type IntegerSliceFuncStringReducer struct {
	points []IntegerPoint
	fn     IntegerReduceStringSliceFunc
}

// NewIntegerSliceFuncStringReducer creates a new IntegerSliceFuncStringReducer.
func NewIntegerSliceFuncStringReducer(fn IntegerReduceStringSliceFunc) *IntegerSliceFuncStringReducer {
	return &IntegerSliceFuncStringReducer{fn: fn}
}

// AggregateInteger copies the IntegerPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *IntegerSliceFuncStringReducer) AggregateInteger(p *IntegerPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateIntegerBulk performs a bulk copy of IntegerPoints into the internal slice.
// This is a more efficient version of calling AggregateInteger on each point.
func (r *IntegerSliceFuncStringReducer) AggregateIntegerBulk(points []IntegerPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *IntegerSliceFuncStringReducer) Emit() []StringPoint {
	return r.fn(r.points)
}

// IntegerReduceBooleanFunc is the function called by a IntegerPoint reducer.
type IntegerReduceBooleanFunc func(prev *BooleanPoint, curr *IntegerPoint) (t int64, v bool, aux []interface{})

// IntegerFuncBooleanReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type IntegerFuncBooleanReducer struct {
	prev *BooleanPoint
	fn   IntegerReduceBooleanFunc
}

// NewIntegerFuncBooleanReducer creates a new IntegerFuncBooleanReducer.
func NewIntegerFuncBooleanReducer(fn IntegerReduceBooleanFunc, prev *BooleanPoint) *IntegerFuncBooleanReducer {
	return &IntegerFuncBooleanReducer{fn: fn, prev: prev}
}

// AggregateInteger takes a IntegerPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *IntegerFuncBooleanReducer) AggregateInteger(p *IntegerPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &BooleanPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateInteger.
func (r *IntegerFuncBooleanReducer) Emit() []BooleanPoint {
	return []BooleanPoint{*r.prev}
}

// IntegerReduceBooleanSliceFunc is the function called by a IntegerPoint reducer.
type IntegerReduceBooleanSliceFunc func(a []IntegerPoint) []BooleanPoint

// IntegerSliceFuncBooleanReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type IntegerSliceFuncBooleanReducer struct {
	points []IntegerPoint
	fn     IntegerReduceBooleanSliceFunc
}

// NewIntegerSliceFuncBooleanReducer creates a new IntegerSliceFuncBooleanReducer.
func NewIntegerSliceFuncBooleanReducer(fn IntegerReduceBooleanSliceFunc) *IntegerSliceFuncBooleanReducer {
	return &IntegerSliceFuncBooleanReducer{fn: fn}
}

// AggregateInteger copies the IntegerPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *IntegerSliceFuncBooleanReducer) AggregateInteger(p *IntegerPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateIntegerBulk performs a bulk copy of IntegerPoints into the internal slice.
// This is a more efficient version of calling AggregateInteger on each point.
func (r *IntegerSliceFuncBooleanReducer) AggregateIntegerBulk(points []IntegerPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *IntegerSliceFuncBooleanReducer) Emit() []BooleanPoint {
	return r.fn(r.points)
}

// IntegerSumHllReducer returns the HLL sketch for a series, in string form
type IntegerSumHllReducer struct {
	plus *hll.Plus
}

// func NewIntegerSumHllReducer creates a new IntegerSumHllReducer
func NewIntegerSumHllReducer() *IntegerSumHllReducer {
	return &IntegerSumHllReducer{plus: hll.NewDefaultPlus()}
}

// AggregateInteger aggregates a point into the reducer.
func (r *IntegerSumHllReducer) AggregateInteger(p *IntegerPoint) {

	buf := new(bytes.Buffer)
	binary.Write(buf, binary.BigEndian, p.Value)
	b := buf.Bytes()

	r.plus.Add(b)
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *IntegerSumHllReducer) Emit() []StringPoint {
	return []StringPoint{
		marshalPlus(r.plus, nil),
	}
}

// IntegerDistinctReducer returns the distinct points in a series.
type IntegerDistinctReducer struct {
	m map[int64]IntegerPoint
}

// NewIntegerDistinctReducer creates a new IntegerDistinctReducer.
func NewIntegerDistinctReducer() *IntegerDistinctReducer {
	return &IntegerDistinctReducer{m: make(map[int64]IntegerPoint)}
}

// AggregateInteger aggregates a point into the reducer.
func (r *IntegerDistinctReducer) AggregateInteger(p *IntegerPoint) {
	if _, ok := r.m[p.Value]; !ok {
		r.m[p.Value] = *p
	}
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *IntegerDistinctReducer) Emit() []IntegerPoint {
	points := make([]IntegerPoint, 0, len(r.m))
	for _, p := range r.m {
		points = append(points, IntegerPoint{Time: p.Time, Value: p.Value})
	}
	sort.Sort(integerPoints(points))
	return points
}

// IntegerElapsedReducer calculates the elapsed of the aggregated points.
type IntegerElapsedReducer struct {
	unitConversion int64
	prev           IntegerPoint
	curr           IntegerPoint
}

// NewIntegerElapsedReducer creates a new IntegerElapsedReducer.
func NewIntegerElapsedReducer(interval Interval) *IntegerElapsedReducer {
	return &IntegerElapsedReducer{
		unitConversion: int64(interval.Duration),
		prev:           IntegerPoint{Nil: true},
		curr:           IntegerPoint{Nil: true},
	}
}

// AggregateInteger aggregates a point into the reducer and updates the current window.
func (r *IntegerElapsedReducer) AggregateInteger(p *IntegerPoint) {
	r.prev = r.curr
	r.curr = *p
}

// Emit emits the elapsed of the reducer at the current point.
func (r *IntegerElapsedReducer) Emit() []IntegerPoint {
	if !r.prev.Nil {
		elapsed := (r.curr.Time - r.prev.Time) / r.unitConversion
		return []IntegerPoint{
			{Time: r.curr.Time, Value: elapsed},
		}
	}
	return nil
}

// IntegerSampleReducer implements a reservoir sampling to calculate a random subset of points
type IntegerSampleReducer struct {
	count int        // how many points we've iterated over
	rng   *rand.Rand // random number generator for each reducer

	points integerPoints // the reservoir
}

// NewIntegerSampleReducer creates a new IntegerSampleReducer
func NewIntegerSampleReducer(size int) *IntegerSampleReducer {
	return &IntegerSampleReducer{
		rng:    rand.New(rand.NewSource(time.Now().UnixNano())), // seed with current time as suggested by https://golang.org/pkg/math/rand/
		points: make(integerPoints, size),
	}
}

// AggregateInteger aggregates a point into the reducer.
func (r *IntegerSampleReducer) AggregateInteger(p *IntegerPoint) {
	r.count++
	// Fill the reservoir with the first n points
	if r.count-1 < len(r.points) {
		p.CopyTo(&r.points[r.count-1])
		return
	}

	// Generate a random integer between 1 and the count and
	// if that number is less than the length of the slice
	// replace the point at that index rnd with p.
	rnd := r.rng.Intn(r.count)
	if rnd < len(r.points) {
		p.CopyTo(&r.points[rnd])
	}
}

// Emit emits the reservoir sample as many points.
func (r *IntegerSampleReducer) Emit() []IntegerPoint {
	min := len(r.points)
	if r.count < min {
		min = r.count
	}
	pts := r.points[:min]
	sort.Sort(pts)
	return pts
}

// UnsignedPointAggregator aggregates points to produce a single point.
type UnsignedPointAggregator interface {
	AggregateUnsigned(p *UnsignedPoint)
}

// UnsignedBulkPointAggregator aggregates multiple points at a time.
type UnsignedBulkPointAggregator interface {
	AggregateUnsignedBulk(points []UnsignedPoint)
}

// UnsignedPointEmitter produces a single point from an aggregate.
type UnsignedPointEmitter interface {
	Emit() []UnsignedPoint
}

// UnsignedReduceFloatFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceFloatFunc func(prev *FloatPoint, curr *UnsignedPoint) (t int64, v float64, aux []interface{})

// UnsignedFuncFloatReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type UnsignedFuncFloatReducer struct {
	prev *FloatPoint
	fn   UnsignedReduceFloatFunc
}

// NewUnsignedFuncFloatReducer creates a new UnsignedFuncFloatReducer.
func NewUnsignedFuncFloatReducer(fn UnsignedReduceFloatFunc, prev *FloatPoint) *UnsignedFuncFloatReducer {
	return &UnsignedFuncFloatReducer{fn: fn, prev: prev}
}

// AggregateUnsigned takes a UnsignedPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *UnsignedFuncFloatReducer) AggregateUnsigned(p *UnsignedPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &FloatPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateUnsigned.
func (r *UnsignedFuncFloatReducer) Emit() []FloatPoint {
	return []FloatPoint{*r.prev}
}

// UnsignedReduceFloatSliceFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceFloatSliceFunc func(a []UnsignedPoint) []FloatPoint

// UnsignedSliceFuncFloatReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type UnsignedSliceFuncFloatReducer struct {
	points []UnsignedPoint
	fn     UnsignedReduceFloatSliceFunc
}

// NewUnsignedSliceFuncFloatReducer creates a new UnsignedSliceFuncFloatReducer.
func NewUnsignedSliceFuncFloatReducer(fn UnsignedReduceFloatSliceFunc) *UnsignedSliceFuncFloatReducer {
	return &UnsignedSliceFuncFloatReducer{fn: fn}
}

// AggregateUnsigned copies the UnsignedPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *UnsignedSliceFuncFloatReducer) AggregateUnsigned(p *UnsignedPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateUnsignedBulk performs a bulk copy of UnsignedPoints into the internal slice.
// This is a more efficient version of calling AggregateUnsigned on each point.
func (r *UnsignedSliceFuncFloatReducer) AggregateUnsignedBulk(points []UnsignedPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *UnsignedSliceFuncFloatReducer) Emit() []FloatPoint {
	return r.fn(r.points)
}

// UnsignedReduceIntegerFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceIntegerFunc func(prev *IntegerPoint, curr *UnsignedPoint) (t int64, v int64, aux []interface{})

// UnsignedFuncIntegerReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type UnsignedFuncIntegerReducer struct {
	prev *IntegerPoint
	fn   UnsignedReduceIntegerFunc
}

// NewUnsignedFuncIntegerReducer creates a new UnsignedFuncIntegerReducer.
func NewUnsignedFuncIntegerReducer(fn UnsignedReduceIntegerFunc, prev *IntegerPoint) *UnsignedFuncIntegerReducer {
	return &UnsignedFuncIntegerReducer{fn: fn, prev: prev}
}

// AggregateUnsigned takes a UnsignedPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *UnsignedFuncIntegerReducer) AggregateUnsigned(p *UnsignedPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &IntegerPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateUnsigned.
func (r *UnsignedFuncIntegerReducer) Emit() []IntegerPoint {
	return []IntegerPoint{*r.prev}
}

// UnsignedReduceIntegerSliceFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceIntegerSliceFunc func(a []UnsignedPoint) []IntegerPoint

// UnsignedSliceFuncIntegerReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type UnsignedSliceFuncIntegerReducer struct {
	points []UnsignedPoint
	fn     UnsignedReduceIntegerSliceFunc
}

// NewUnsignedSliceFuncIntegerReducer creates a new UnsignedSliceFuncIntegerReducer.
func NewUnsignedSliceFuncIntegerReducer(fn UnsignedReduceIntegerSliceFunc) *UnsignedSliceFuncIntegerReducer {
	return &UnsignedSliceFuncIntegerReducer{fn: fn}
}

// AggregateUnsigned copies the UnsignedPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *UnsignedSliceFuncIntegerReducer) AggregateUnsigned(p *UnsignedPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateUnsignedBulk performs a bulk copy of UnsignedPoints into the internal slice.
// This is a more efficient version of calling AggregateUnsigned on each point.
func (r *UnsignedSliceFuncIntegerReducer) AggregateUnsignedBulk(points []UnsignedPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *UnsignedSliceFuncIntegerReducer) Emit() []IntegerPoint {
	return r.fn(r.points)
}

// UnsignedReduceFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceFunc func(prev *UnsignedPoint, curr *UnsignedPoint) (t int64, v uint64, aux []interface{})

// UnsignedFuncReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type UnsignedFuncReducer struct {
	prev *UnsignedPoint
	fn   UnsignedReduceFunc
}

// NewUnsignedFuncReducer creates a new UnsignedFuncUnsignedReducer.
func NewUnsignedFuncReducer(fn UnsignedReduceFunc, prev *UnsignedPoint) *UnsignedFuncReducer {
	return &UnsignedFuncReducer{fn: fn, prev: prev}
}

// AggregateUnsigned takes a UnsignedPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *UnsignedFuncReducer) AggregateUnsigned(p *UnsignedPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &UnsignedPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateUnsigned.
func (r *UnsignedFuncReducer) Emit() []UnsignedPoint {
	return []UnsignedPoint{*r.prev}
}

// UnsignedReduceSliceFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceSliceFunc func(a []UnsignedPoint) []UnsignedPoint

// UnsignedSliceFuncReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type UnsignedSliceFuncReducer struct {
	points []UnsignedPoint
	fn     UnsignedReduceSliceFunc
}

// NewUnsignedSliceFuncReducer creates a new UnsignedSliceFuncReducer.
func NewUnsignedSliceFuncReducer(fn UnsignedReduceSliceFunc) *UnsignedSliceFuncReducer {
	return &UnsignedSliceFuncReducer{fn: fn}
}

// AggregateUnsigned copies the UnsignedPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *UnsignedSliceFuncReducer) AggregateUnsigned(p *UnsignedPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateUnsignedBulk performs a bulk copy of UnsignedPoints into the internal slice.
// This is a more efficient version of calling AggregateUnsigned on each point.
func (r *UnsignedSliceFuncReducer) AggregateUnsignedBulk(points []UnsignedPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *UnsignedSliceFuncReducer) Emit() []UnsignedPoint {
	return r.fn(r.points)
}

// UnsignedReduceStringFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceStringFunc func(prev *StringPoint, curr *UnsignedPoint) (t int64, v string, aux []interface{})

// UnsignedFuncStringReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type UnsignedFuncStringReducer struct {
	prev *StringPoint
	fn   UnsignedReduceStringFunc
}

// NewUnsignedFuncStringReducer creates a new UnsignedFuncStringReducer.
func NewUnsignedFuncStringReducer(fn UnsignedReduceStringFunc, prev *StringPoint) *UnsignedFuncStringReducer {
	return &UnsignedFuncStringReducer{fn: fn, prev: prev}
}

// AggregateUnsigned takes a UnsignedPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *UnsignedFuncStringReducer) AggregateUnsigned(p *UnsignedPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &StringPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateUnsigned.
func (r *UnsignedFuncStringReducer) Emit() []StringPoint {
	return []StringPoint{*r.prev}
}

// UnsignedReduceStringSliceFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceStringSliceFunc func(a []UnsignedPoint) []StringPoint

// UnsignedSliceFuncStringReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type UnsignedSliceFuncStringReducer struct {
	points []UnsignedPoint
	fn     UnsignedReduceStringSliceFunc
}

// NewUnsignedSliceFuncStringReducer creates a new UnsignedSliceFuncStringReducer.
func NewUnsignedSliceFuncStringReducer(fn UnsignedReduceStringSliceFunc) *UnsignedSliceFuncStringReducer {
	return &UnsignedSliceFuncStringReducer{fn: fn}
}

// AggregateUnsigned copies the UnsignedPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *UnsignedSliceFuncStringReducer) AggregateUnsigned(p *UnsignedPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateUnsignedBulk performs a bulk copy of UnsignedPoints into the internal slice.
// This is a more efficient version of calling AggregateUnsigned on each point.
func (r *UnsignedSliceFuncStringReducer) AggregateUnsignedBulk(points []UnsignedPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *UnsignedSliceFuncStringReducer) Emit() []StringPoint {
	return r.fn(r.points)
}

// UnsignedReduceBooleanFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceBooleanFunc func(prev *BooleanPoint, curr *UnsignedPoint) (t int64, v bool, aux []interface{})

// UnsignedFuncBooleanReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type UnsignedFuncBooleanReducer struct {
	prev *BooleanPoint
	fn   UnsignedReduceBooleanFunc
}

// NewUnsignedFuncBooleanReducer creates a new UnsignedFuncBooleanReducer.
func NewUnsignedFuncBooleanReducer(fn UnsignedReduceBooleanFunc, prev *BooleanPoint) *UnsignedFuncBooleanReducer {
	return &UnsignedFuncBooleanReducer{fn: fn, prev: prev}
}

// AggregateUnsigned takes a UnsignedPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *UnsignedFuncBooleanReducer) AggregateUnsigned(p *UnsignedPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &BooleanPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateUnsigned.
func (r *UnsignedFuncBooleanReducer) Emit() []BooleanPoint {
	return []BooleanPoint{*r.prev}
}

// UnsignedReduceBooleanSliceFunc is the function called by a UnsignedPoint reducer.
type UnsignedReduceBooleanSliceFunc func(a []UnsignedPoint) []BooleanPoint

// UnsignedSliceFuncBooleanReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type UnsignedSliceFuncBooleanReducer struct {
	points []UnsignedPoint
	fn     UnsignedReduceBooleanSliceFunc
}

// NewUnsignedSliceFuncBooleanReducer creates a new UnsignedSliceFuncBooleanReducer.
func NewUnsignedSliceFuncBooleanReducer(fn UnsignedReduceBooleanSliceFunc) *UnsignedSliceFuncBooleanReducer {
	return &UnsignedSliceFuncBooleanReducer{fn: fn}
}

// AggregateUnsigned copies the UnsignedPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *UnsignedSliceFuncBooleanReducer) AggregateUnsigned(p *UnsignedPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateUnsignedBulk performs a bulk copy of UnsignedPoints into the internal slice.
// This is a more efficient version of calling AggregateUnsigned on each point.
func (r *UnsignedSliceFuncBooleanReducer) AggregateUnsignedBulk(points []UnsignedPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *UnsignedSliceFuncBooleanReducer) Emit() []BooleanPoint {
	return r.fn(r.points)
}

// UnsignedSumHllReducer returns the HLL sketch for a series, in string form
type UnsignedSumHllReducer struct {
	plus *hll.Plus
}

// func NewUnsignedSumHllReducer creates a new UnsignedSumHllReducer
func NewUnsignedSumHllReducer() *UnsignedSumHllReducer {
	return &UnsignedSumHllReducer{plus: hll.NewDefaultPlus()}
}

// AggregateUnsigned aggregates a point into the reducer.
func (r *UnsignedSumHllReducer) AggregateUnsigned(p *UnsignedPoint) {

	buf := new(bytes.Buffer)
	binary.Write(buf, binary.BigEndian, p.Value)
	b := buf.Bytes()

	r.plus.Add(b)
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *UnsignedSumHllReducer) Emit() []StringPoint {
	return []StringPoint{
		marshalPlus(r.plus, nil),
	}
}

// UnsignedDistinctReducer returns the distinct points in a series.
type UnsignedDistinctReducer struct {
	m map[uint64]UnsignedPoint
}

// NewUnsignedDistinctReducer creates a new UnsignedDistinctReducer.
func NewUnsignedDistinctReducer() *UnsignedDistinctReducer {
	return &UnsignedDistinctReducer{m: make(map[uint64]UnsignedPoint)}
}

// AggregateUnsigned aggregates a point into the reducer.
func (r *UnsignedDistinctReducer) AggregateUnsigned(p *UnsignedPoint) {
	if _, ok := r.m[p.Value]; !ok {
		r.m[p.Value] = *p
	}
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *UnsignedDistinctReducer) Emit() []UnsignedPoint {
	points := make([]UnsignedPoint, 0, len(r.m))
	for _, p := range r.m {
		points = append(points, UnsignedPoint{Time: p.Time, Value: p.Value})
	}
	sort.Sort(unsignedPoints(points))
	return points
}

// UnsignedElapsedReducer calculates the elapsed of the aggregated points.
type UnsignedElapsedReducer struct {
	unitConversion int64
	prev           UnsignedPoint
	curr           UnsignedPoint
}

// NewUnsignedElapsedReducer creates a new UnsignedElapsedReducer.
func NewUnsignedElapsedReducer(interval Interval) *UnsignedElapsedReducer {
	return &UnsignedElapsedReducer{
		unitConversion: int64(interval.Duration),
		prev:           UnsignedPoint{Nil: true},
		curr:           UnsignedPoint{Nil: true},
	}
}

// AggregateUnsigned aggregates a point into the reducer and updates the current window.
func (r *UnsignedElapsedReducer) AggregateUnsigned(p *UnsignedPoint) {
	r.prev = r.curr
	r.curr = *p
}

// Emit emits the elapsed of the reducer at the current point.
func (r *UnsignedElapsedReducer) Emit() []IntegerPoint {
	if !r.prev.Nil {
		elapsed := (r.curr.Time - r.prev.Time) / r.unitConversion
		return []IntegerPoint{
			{Time: r.curr.Time, Value: elapsed},
		}
	}
	return nil
}

// UnsignedSampleReducer implements a reservoir sampling to calculate a random subset of points
type UnsignedSampleReducer struct {
	count int        // how many points we've iterated over
	rng   *rand.Rand // random number generator for each reducer

	points unsignedPoints // the reservoir
}

// NewUnsignedSampleReducer creates a new UnsignedSampleReducer
func NewUnsignedSampleReducer(size int) *UnsignedSampleReducer {
	return &UnsignedSampleReducer{
		rng:    rand.New(rand.NewSource(time.Now().UnixNano())), // seed with current time as suggested by https://golang.org/pkg/math/rand/
		points: make(unsignedPoints, size),
	}
}

// AggregateUnsigned aggregates a point into the reducer.
func (r *UnsignedSampleReducer) AggregateUnsigned(p *UnsignedPoint) {
	r.count++
	// Fill the reservoir with the first n points
	if r.count-1 < len(r.points) {
		p.CopyTo(&r.points[r.count-1])
		return
	}

	// Generate a random integer between 1 and the count and
	// if that number is less than the length of the slice
	// replace the point at that index rnd with p.
	rnd := r.rng.Intn(r.count)
	if rnd < len(r.points) {
		p.CopyTo(&r.points[rnd])
	}
}

// Emit emits the reservoir sample as many points.
func (r *UnsignedSampleReducer) Emit() []UnsignedPoint {
	min := len(r.points)
	if r.count < min {
		min = r.count
	}
	pts := r.points[:min]
	sort.Sort(pts)
	return pts
}

// StringPointAggregator aggregates points to produce a single point.
type StringPointAggregator interface {
	AggregateString(p *StringPoint)
}

// StringBulkPointAggregator aggregates multiple points at a time.
type StringBulkPointAggregator interface {
	AggregateStringBulk(points []StringPoint)
}

// StringPointEmitter produces a single point from an aggregate.
type StringPointEmitter interface {
	Emit() []StringPoint
}

// StringReduceFloatFunc is the function called by a StringPoint reducer.
type StringReduceFloatFunc func(prev *FloatPoint, curr *StringPoint) (t int64, v float64, aux []interface{})

// StringFuncFloatReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type StringFuncFloatReducer struct {
	prev *FloatPoint
	fn   StringReduceFloatFunc
}

// NewStringFuncFloatReducer creates a new StringFuncFloatReducer.
func NewStringFuncFloatReducer(fn StringReduceFloatFunc, prev *FloatPoint) *StringFuncFloatReducer {
	return &StringFuncFloatReducer{fn: fn, prev: prev}
}

// AggregateString takes a StringPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *StringFuncFloatReducer) AggregateString(p *StringPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &FloatPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateString.
func (r *StringFuncFloatReducer) Emit() []FloatPoint {
	return []FloatPoint{*r.prev}
}

// StringReduceFloatSliceFunc is the function called by a StringPoint reducer.
type StringReduceFloatSliceFunc func(a []StringPoint) []FloatPoint

// StringSliceFuncFloatReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type StringSliceFuncFloatReducer struct {
	points []StringPoint
	fn     StringReduceFloatSliceFunc
}

// NewStringSliceFuncFloatReducer creates a new StringSliceFuncFloatReducer.
func NewStringSliceFuncFloatReducer(fn StringReduceFloatSliceFunc) *StringSliceFuncFloatReducer {
	return &StringSliceFuncFloatReducer{fn: fn}
}

// AggregateString copies the StringPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *StringSliceFuncFloatReducer) AggregateString(p *StringPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateStringBulk performs a bulk copy of StringPoints into the internal slice.
// This is a more efficient version of calling AggregateString on each point.
func (r *StringSliceFuncFloatReducer) AggregateStringBulk(points []StringPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *StringSliceFuncFloatReducer) Emit() []FloatPoint {
	return r.fn(r.points)
}

// StringReduceIntegerFunc is the function called by a StringPoint reducer.
type StringReduceIntegerFunc func(prev *IntegerPoint, curr *StringPoint) (t int64, v int64, aux []interface{})

// StringFuncIntegerReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type StringFuncIntegerReducer struct {
	prev *IntegerPoint
	fn   StringReduceIntegerFunc
}

// NewStringFuncIntegerReducer creates a new StringFuncIntegerReducer.
func NewStringFuncIntegerReducer(fn StringReduceIntegerFunc, prev *IntegerPoint) *StringFuncIntegerReducer {
	return &StringFuncIntegerReducer{fn: fn, prev: prev}
}

// AggregateString takes a StringPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *StringFuncIntegerReducer) AggregateString(p *StringPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &IntegerPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateString.
func (r *StringFuncIntegerReducer) Emit() []IntegerPoint {
	return []IntegerPoint{*r.prev}
}

// StringReduceIntegerSliceFunc is the function called by a StringPoint reducer.
type StringReduceIntegerSliceFunc func(a []StringPoint) []IntegerPoint

// StringSliceFuncIntegerReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type StringSliceFuncIntegerReducer struct {
	points []StringPoint
	fn     StringReduceIntegerSliceFunc
}

// NewStringSliceFuncIntegerReducer creates a new StringSliceFuncIntegerReducer.
func NewStringSliceFuncIntegerReducer(fn StringReduceIntegerSliceFunc) *StringSliceFuncIntegerReducer {
	return &StringSliceFuncIntegerReducer{fn: fn}
}

// AggregateString copies the StringPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *StringSliceFuncIntegerReducer) AggregateString(p *StringPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateStringBulk performs a bulk copy of StringPoints into the internal slice.
// This is a more efficient version of calling AggregateString on each point.
func (r *StringSliceFuncIntegerReducer) AggregateStringBulk(points []StringPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *StringSliceFuncIntegerReducer) Emit() []IntegerPoint {
	return r.fn(r.points)
}

// StringReduceUnsignedFunc is the function called by a StringPoint reducer.
type StringReduceUnsignedFunc func(prev *UnsignedPoint, curr *StringPoint) (t int64, v uint64, aux []interface{})

// StringFuncUnsignedReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type StringFuncUnsignedReducer struct {
	prev *UnsignedPoint
	fn   StringReduceUnsignedFunc
}

// NewStringFuncUnsignedReducer creates a new StringFuncUnsignedReducer.
func NewStringFuncUnsignedReducer(fn StringReduceUnsignedFunc, prev *UnsignedPoint) *StringFuncUnsignedReducer {
	return &StringFuncUnsignedReducer{fn: fn, prev: prev}
}

// AggregateString takes a StringPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *StringFuncUnsignedReducer) AggregateString(p *StringPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &UnsignedPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateString.
func (r *StringFuncUnsignedReducer) Emit() []UnsignedPoint {
	return []UnsignedPoint{*r.prev}
}

// StringReduceUnsignedSliceFunc is the function called by a StringPoint reducer.
type StringReduceUnsignedSliceFunc func(a []StringPoint) []UnsignedPoint

// StringSliceFuncUnsignedReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type StringSliceFuncUnsignedReducer struct {
	points []StringPoint
	fn     StringReduceUnsignedSliceFunc
}

// NewStringSliceFuncUnsignedReducer creates a new StringSliceFuncUnsignedReducer.
func NewStringSliceFuncUnsignedReducer(fn StringReduceUnsignedSliceFunc) *StringSliceFuncUnsignedReducer {
	return &StringSliceFuncUnsignedReducer{fn: fn}
}

// AggregateString copies the StringPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *StringSliceFuncUnsignedReducer) AggregateString(p *StringPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateStringBulk performs a bulk copy of StringPoints into the internal slice.
// This is a more efficient version of calling AggregateString on each point.
func (r *StringSliceFuncUnsignedReducer) AggregateStringBulk(points []StringPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *StringSliceFuncUnsignedReducer) Emit() []UnsignedPoint {
	return r.fn(r.points)
}

// StringReduceFunc is the function called by a StringPoint reducer.
type StringReduceFunc func(prev *StringPoint, curr *StringPoint) (t int64, v string, aux []interface{})

// StringFuncReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type StringFuncReducer struct {
	prev *StringPoint
	fn   StringReduceFunc
}

// NewStringFuncReducer creates a new StringFuncStringReducer.
func NewStringFuncReducer(fn StringReduceFunc, prev *StringPoint) *StringFuncReducer {
	return &StringFuncReducer{fn: fn, prev: prev}
}

// AggregateString takes a StringPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *StringFuncReducer) AggregateString(p *StringPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &StringPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateString.
func (r *StringFuncReducer) Emit() []StringPoint {
	return []StringPoint{*r.prev}
}

// StringReduceSliceFunc is the function called by a StringPoint reducer.
type StringReduceSliceFunc func(a []StringPoint) []StringPoint

// StringSliceFuncReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type StringSliceFuncReducer struct {
	points []StringPoint
	fn     StringReduceSliceFunc
}

// NewStringSliceFuncReducer creates a new StringSliceFuncReducer.
func NewStringSliceFuncReducer(fn StringReduceSliceFunc) *StringSliceFuncReducer {
	return &StringSliceFuncReducer{fn: fn}
}

// AggregateString copies the StringPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *StringSliceFuncReducer) AggregateString(p *StringPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateStringBulk performs a bulk copy of StringPoints into the internal slice.
// This is a more efficient version of calling AggregateString on each point.
func (r *StringSliceFuncReducer) AggregateStringBulk(points []StringPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *StringSliceFuncReducer) Emit() []StringPoint {
	return r.fn(r.points)
}

// StringReduceBooleanFunc is the function called by a StringPoint reducer.
type StringReduceBooleanFunc func(prev *BooleanPoint, curr *StringPoint) (t int64, v bool, aux []interface{})

// StringFuncBooleanReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type StringFuncBooleanReducer struct {
	prev *BooleanPoint
	fn   StringReduceBooleanFunc
}

// NewStringFuncBooleanReducer creates a new StringFuncBooleanReducer.
func NewStringFuncBooleanReducer(fn StringReduceBooleanFunc, prev *BooleanPoint) *StringFuncBooleanReducer {
	return &StringFuncBooleanReducer{fn: fn, prev: prev}
}

// AggregateString takes a StringPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *StringFuncBooleanReducer) AggregateString(p *StringPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &BooleanPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateString.
func (r *StringFuncBooleanReducer) Emit() []BooleanPoint {
	return []BooleanPoint{*r.prev}
}

// StringReduceBooleanSliceFunc is the function called by a StringPoint reducer.
type StringReduceBooleanSliceFunc func(a []StringPoint) []BooleanPoint

// StringSliceFuncBooleanReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type StringSliceFuncBooleanReducer struct {
	points []StringPoint
	fn     StringReduceBooleanSliceFunc
}

// NewStringSliceFuncBooleanReducer creates a new StringSliceFuncBooleanReducer.
func NewStringSliceFuncBooleanReducer(fn StringReduceBooleanSliceFunc) *StringSliceFuncBooleanReducer {
	return &StringSliceFuncBooleanReducer{fn: fn}
}

// AggregateString copies the StringPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *StringSliceFuncBooleanReducer) AggregateString(p *StringPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateStringBulk performs a bulk copy of StringPoints into the internal slice.
// This is a more efficient version of calling AggregateString on each point.
func (r *StringSliceFuncBooleanReducer) AggregateStringBulk(points []StringPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *StringSliceFuncBooleanReducer) Emit() []BooleanPoint {
	return r.fn(r.points)
}

// StringSumHllReducer returns the HLL sketch for a series, in string form
type StringSumHllReducer struct {
	plus *hll.Plus
}

// func NewStringSumHllReducer creates a new StringSumHllReducer
func NewStringSumHllReducer() *StringSumHllReducer {
	return &StringSumHllReducer{plus: hll.NewDefaultPlus()}
}

// AggregateString aggregates a point into the reducer.
func (r *StringSumHllReducer) AggregateString(p *StringPoint) {

	b := []byte(p.Value)

	r.plus.Add(b)
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *StringSumHllReducer) Emit() []StringPoint {
	return []StringPoint{
		marshalPlus(r.plus, nil),
	}
}

// StringDistinctReducer returns the distinct points in a series.
type StringDistinctReducer struct {
	m map[string]StringPoint
}

// NewStringDistinctReducer creates a new StringDistinctReducer.
func NewStringDistinctReducer() *StringDistinctReducer {
	return &StringDistinctReducer{m: make(map[string]StringPoint)}
}

// AggregateString aggregates a point into the reducer.
func (r *StringDistinctReducer) AggregateString(p *StringPoint) {
	if _, ok := r.m[p.Value]; !ok {
		r.m[p.Value] = *p
	}
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *StringDistinctReducer) Emit() []StringPoint {
	points := make([]StringPoint, 0, len(r.m))
	for _, p := range r.m {
		points = append(points, StringPoint{Time: p.Time, Value: p.Value})
	}
	sort.Sort(stringPoints(points))
	return points
}

// StringElapsedReducer calculates the elapsed of the aggregated points.
type StringElapsedReducer struct {
	unitConversion int64
	prev           StringPoint
	curr           StringPoint
}

// NewStringElapsedReducer creates a new StringElapsedReducer.
func NewStringElapsedReducer(interval Interval) *StringElapsedReducer {
	return &StringElapsedReducer{
		unitConversion: int64(interval.Duration),
		prev:           StringPoint{Nil: true},
		curr:           StringPoint{Nil: true},
	}
}

// AggregateString aggregates a point into the reducer and updates the current window.
func (r *StringElapsedReducer) AggregateString(p *StringPoint) {
	r.prev = r.curr
	r.curr = *p
}

// Emit emits the elapsed of the reducer at the current point.
func (r *StringElapsedReducer) Emit() []IntegerPoint {
	if !r.prev.Nil {
		elapsed := (r.curr.Time - r.prev.Time) / r.unitConversion
		return []IntegerPoint{
			{Time: r.curr.Time, Value: elapsed},
		}
	}
	return nil
}

// StringSampleReducer implements a reservoir sampling to calculate a random subset of points
type StringSampleReducer struct {
	count int        // how many points we've iterated over
	rng   *rand.Rand // random number generator for each reducer

	points stringPoints // the reservoir
}

// NewStringSampleReducer creates a new StringSampleReducer
func NewStringSampleReducer(size int) *StringSampleReducer {
	return &StringSampleReducer{
		rng:    rand.New(rand.NewSource(time.Now().UnixNano())), // seed with current time as suggested by https://golang.org/pkg/math/rand/
		points: make(stringPoints, size),
	}
}

// AggregateString aggregates a point into the reducer.
func (r *StringSampleReducer) AggregateString(p *StringPoint) {
	r.count++
	// Fill the reservoir with the first n points
	if r.count-1 < len(r.points) {
		p.CopyTo(&r.points[r.count-1])
		return
	}

	// Generate a random integer between 1 and the count and
	// if that number is less than the length of the slice
	// replace the point at that index rnd with p.
	rnd := r.rng.Intn(r.count)
	if rnd < len(r.points) {
		p.CopyTo(&r.points[rnd])
	}
}

// Emit emits the reservoir sample as many points.
func (r *StringSampleReducer) Emit() []StringPoint {
	min := len(r.points)
	if r.count < min {
		min = r.count
	}
	pts := r.points[:min]
	sort.Sort(pts)
	return pts
}

// BooleanPointAggregator aggregates points to produce a single point.
type BooleanPointAggregator interface {
	AggregateBoolean(p *BooleanPoint)
}

// BooleanBulkPointAggregator aggregates multiple points at a time.
type BooleanBulkPointAggregator interface {
	AggregateBooleanBulk(points []BooleanPoint)
}

// BooleanPointEmitter produces a single point from an aggregate.
type BooleanPointEmitter interface {
	Emit() []BooleanPoint
}

// BooleanReduceFloatFunc is the function called by a BooleanPoint reducer.
type BooleanReduceFloatFunc func(prev *FloatPoint, curr *BooleanPoint) (t int64, v float64, aux []interface{})

// BooleanFuncFloatReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type BooleanFuncFloatReducer struct {
	prev *FloatPoint
	fn   BooleanReduceFloatFunc
}

// NewBooleanFuncFloatReducer creates a new BooleanFuncFloatReducer.
func NewBooleanFuncFloatReducer(fn BooleanReduceFloatFunc, prev *FloatPoint) *BooleanFuncFloatReducer {
	return &BooleanFuncFloatReducer{fn: fn, prev: prev}
}

// AggregateBoolean takes a BooleanPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *BooleanFuncFloatReducer) AggregateBoolean(p *BooleanPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &FloatPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateBoolean.
func (r *BooleanFuncFloatReducer) Emit() []FloatPoint {
	return []FloatPoint{*r.prev}
}

// BooleanReduceFloatSliceFunc is the function called by a BooleanPoint reducer.
type BooleanReduceFloatSliceFunc func(a []BooleanPoint) []FloatPoint

// BooleanSliceFuncFloatReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type BooleanSliceFuncFloatReducer struct {
	points []BooleanPoint
	fn     BooleanReduceFloatSliceFunc
}

// NewBooleanSliceFuncFloatReducer creates a new BooleanSliceFuncFloatReducer.
func NewBooleanSliceFuncFloatReducer(fn BooleanReduceFloatSliceFunc) *BooleanSliceFuncFloatReducer {
	return &BooleanSliceFuncFloatReducer{fn: fn}
}

// AggregateBoolean copies the BooleanPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *BooleanSliceFuncFloatReducer) AggregateBoolean(p *BooleanPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateBooleanBulk performs a bulk copy of BooleanPoints into the internal slice.
// This is a more efficient version of calling AggregateBoolean on each point.
func (r *BooleanSliceFuncFloatReducer) AggregateBooleanBulk(points []BooleanPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *BooleanSliceFuncFloatReducer) Emit() []FloatPoint {
	return r.fn(r.points)
}

// BooleanReduceIntegerFunc is the function called by a BooleanPoint reducer.
type BooleanReduceIntegerFunc func(prev *IntegerPoint, curr *BooleanPoint) (t int64, v int64, aux []interface{})

// BooleanFuncIntegerReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type BooleanFuncIntegerReducer struct {
	prev *IntegerPoint
	fn   BooleanReduceIntegerFunc
}

// NewBooleanFuncIntegerReducer creates a new BooleanFuncIntegerReducer.
func NewBooleanFuncIntegerReducer(fn BooleanReduceIntegerFunc, prev *IntegerPoint) *BooleanFuncIntegerReducer {
	return &BooleanFuncIntegerReducer{fn: fn, prev: prev}
}

// AggregateBoolean takes a BooleanPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *BooleanFuncIntegerReducer) AggregateBoolean(p *BooleanPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &IntegerPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateBoolean.
func (r *BooleanFuncIntegerReducer) Emit() []IntegerPoint {
	return []IntegerPoint{*r.prev}
}

// BooleanReduceIntegerSliceFunc is the function called by a BooleanPoint reducer.
type BooleanReduceIntegerSliceFunc func(a []BooleanPoint) []IntegerPoint

// BooleanSliceFuncIntegerReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type BooleanSliceFuncIntegerReducer struct {
	points []BooleanPoint
	fn     BooleanReduceIntegerSliceFunc
}

// NewBooleanSliceFuncIntegerReducer creates a new BooleanSliceFuncIntegerReducer.
func NewBooleanSliceFuncIntegerReducer(fn BooleanReduceIntegerSliceFunc) *BooleanSliceFuncIntegerReducer {
	return &BooleanSliceFuncIntegerReducer{fn: fn}
}

// AggregateBoolean copies the BooleanPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *BooleanSliceFuncIntegerReducer) AggregateBoolean(p *BooleanPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateBooleanBulk performs a bulk copy of BooleanPoints into the internal slice.
// This is a more efficient version of calling AggregateBoolean on each point.
func (r *BooleanSliceFuncIntegerReducer) AggregateBooleanBulk(points []BooleanPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *BooleanSliceFuncIntegerReducer) Emit() []IntegerPoint {
	return r.fn(r.points)
}

// BooleanReduceUnsignedFunc is the function called by a BooleanPoint reducer.
type BooleanReduceUnsignedFunc func(prev *UnsignedPoint, curr *BooleanPoint) (t int64, v uint64, aux []interface{})

// BooleanFuncUnsignedReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type BooleanFuncUnsignedReducer struct {
	prev *UnsignedPoint
	fn   BooleanReduceUnsignedFunc
}

// NewBooleanFuncUnsignedReducer creates a new BooleanFuncUnsignedReducer.
func NewBooleanFuncUnsignedReducer(fn BooleanReduceUnsignedFunc, prev *UnsignedPoint) *BooleanFuncUnsignedReducer {
	return &BooleanFuncUnsignedReducer{fn: fn, prev: prev}
}

// AggregateBoolean takes a BooleanPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *BooleanFuncUnsignedReducer) AggregateBoolean(p *BooleanPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &UnsignedPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateBoolean.
func (r *BooleanFuncUnsignedReducer) Emit() []UnsignedPoint {
	return []UnsignedPoint{*r.prev}
}

// BooleanReduceUnsignedSliceFunc is the function called by a BooleanPoint reducer.
type BooleanReduceUnsignedSliceFunc func(a []BooleanPoint) []UnsignedPoint

// BooleanSliceFuncUnsignedReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type BooleanSliceFuncUnsignedReducer struct {
	points []BooleanPoint
	fn     BooleanReduceUnsignedSliceFunc
}

// NewBooleanSliceFuncUnsignedReducer creates a new BooleanSliceFuncUnsignedReducer.
func NewBooleanSliceFuncUnsignedReducer(fn BooleanReduceUnsignedSliceFunc) *BooleanSliceFuncUnsignedReducer {
	return &BooleanSliceFuncUnsignedReducer{fn: fn}
}

// AggregateBoolean copies the BooleanPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *BooleanSliceFuncUnsignedReducer) AggregateBoolean(p *BooleanPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateBooleanBulk performs a bulk copy of BooleanPoints into the internal slice.
// This is a more efficient version of calling AggregateBoolean on each point.
func (r *BooleanSliceFuncUnsignedReducer) AggregateBooleanBulk(points []BooleanPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *BooleanSliceFuncUnsignedReducer) Emit() []UnsignedPoint {
	return r.fn(r.points)
}

// BooleanReduceStringFunc is the function called by a BooleanPoint reducer.
type BooleanReduceStringFunc func(prev *StringPoint, curr *BooleanPoint) (t int64, v string, aux []interface{})

// BooleanFuncStringReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type BooleanFuncStringReducer struct {
	prev *StringPoint
	fn   BooleanReduceStringFunc
}

// NewBooleanFuncStringReducer creates a new BooleanFuncStringReducer.
func NewBooleanFuncStringReducer(fn BooleanReduceStringFunc, prev *StringPoint) *BooleanFuncStringReducer {
	return &BooleanFuncStringReducer{fn: fn, prev: prev}
}

// AggregateBoolean takes a BooleanPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *BooleanFuncStringReducer) AggregateBoolean(p *BooleanPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &StringPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateBoolean.
func (r *BooleanFuncStringReducer) Emit() []StringPoint {
	return []StringPoint{*r.prev}
}

// BooleanReduceStringSliceFunc is the function called by a BooleanPoint reducer.
type BooleanReduceStringSliceFunc func(a []BooleanPoint) []StringPoint

// BooleanSliceFuncStringReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type BooleanSliceFuncStringReducer struct {
	points []BooleanPoint
	fn     BooleanReduceStringSliceFunc
}

// NewBooleanSliceFuncStringReducer creates a new BooleanSliceFuncStringReducer.
func NewBooleanSliceFuncStringReducer(fn BooleanReduceStringSliceFunc) *BooleanSliceFuncStringReducer {
	return &BooleanSliceFuncStringReducer{fn: fn}
}

// AggregateBoolean copies the BooleanPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *BooleanSliceFuncStringReducer) AggregateBoolean(p *BooleanPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateBooleanBulk performs a bulk copy of BooleanPoints into the internal slice.
// This is a more efficient version of calling AggregateBoolean on each point.
func (r *BooleanSliceFuncStringReducer) AggregateBooleanBulk(points []BooleanPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *BooleanSliceFuncStringReducer) Emit() []StringPoint {
	return r.fn(r.points)
}

// BooleanReduceFunc is the function called by a BooleanPoint reducer.
type BooleanReduceFunc func(prev *BooleanPoint, curr *BooleanPoint) (t int64, v bool, aux []interface{})

// BooleanFuncReducer is a reducer that reduces
// the passed in points to a single point using a reduce function.
type BooleanFuncReducer struct {
	prev *BooleanPoint
	fn   BooleanReduceFunc
}

// NewBooleanFuncReducer creates a new BooleanFuncBooleanReducer.
func NewBooleanFuncReducer(fn BooleanReduceFunc, prev *BooleanPoint) *BooleanFuncReducer {
	return &BooleanFuncReducer{fn: fn, prev: prev}
}

// AggregateBoolean takes a BooleanPoint and invokes the reduce function with the
// current and new point to modify the current point.
func (r *BooleanFuncReducer) AggregateBoolean(p *BooleanPoint) {
	t, v, aux := r.fn(r.prev, p)
	if r.prev == nil {
		r.prev = &BooleanPoint{}
	}
	r.prev.Time = t
	r.prev.Value = v
	r.prev.Aux = aux
	if p.Aggregated > 1 {
		r.prev.Aggregated += p.Aggregated
	} else {
		r.prev.Aggregated++
	}
}

// Emit emits the point that was generated when reducing the points fed in with AggregateBoolean.
func (r *BooleanFuncReducer) Emit() []BooleanPoint {
	return []BooleanPoint{*r.prev}
}

// BooleanReduceSliceFunc is the function called by a BooleanPoint reducer.
type BooleanReduceSliceFunc func(a []BooleanPoint) []BooleanPoint

// BooleanSliceFuncReducer is a reducer that aggregates
// the passed in points and then invokes the function to reduce the points when they are emitted.
type BooleanSliceFuncReducer struct {
	points []BooleanPoint
	fn     BooleanReduceSliceFunc
}

// NewBooleanSliceFuncReducer creates a new BooleanSliceFuncReducer.
func NewBooleanSliceFuncReducer(fn BooleanReduceSliceFunc) *BooleanSliceFuncReducer {
	return &BooleanSliceFuncReducer{fn: fn}
}

// AggregateBoolean copies the BooleanPoint into the internal slice to be passed
// to the reduce function when Emit is called.
func (r *BooleanSliceFuncReducer) AggregateBoolean(p *BooleanPoint) {
	r.points = append(r.points, *p.Clone())
}

// AggregateBooleanBulk performs a bulk copy of BooleanPoints into the internal slice.
// This is a more efficient version of calling AggregateBoolean on each point.
func (r *BooleanSliceFuncReducer) AggregateBooleanBulk(points []BooleanPoint) {
	r.points = append(r.points, points...)
}

// Emit invokes the reduce function on the aggregated points to generate the aggregated points.
// This method does not clear the points from the internal slice.
func (r *BooleanSliceFuncReducer) Emit() []BooleanPoint {
	return r.fn(r.points)
}

// BooleanSumHllReducer returns the HLL sketch for a series, in string form
type BooleanSumHllReducer struct {
	plus *hll.Plus
}

// func NewBooleanSumHllReducer creates a new BooleanSumHllReducer
func NewBooleanSumHllReducer() *BooleanSumHllReducer {
	return &BooleanSumHllReducer{plus: hll.NewDefaultPlus()}
}

// AggregateBoolean aggregates a point into the reducer.
func (r *BooleanSumHllReducer) AggregateBoolean(p *BooleanPoint) {

	buf := new(bytes.Buffer)
	binary.Write(buf, binary.BigEndian, p.Value)
	b := buf.Bytes()

	r.plus.Add(b)
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *BooleanSumHllReducer) Emit() []StringPoint {
	return []StringPoint{
		marshalPlus(r.plus, nil),
	}
}

// BooleanDistinctReducer returns the distinct points in a series.
type BooleanDistinctReducer struct {
	m map[bool]BooleanPoint
}

// NewBooleanDistinctReducer creates a new BooleanDistinctReducer.
func NewBooleanDistinctReducer() *BooleanDistinctReducer {
	return &BooleanDistinctReducer{m: make(map[bool]BooleanPoint)}
}

// AggregateBoolean aggregates a point into the reducer.
func (r *BooleanDistinctReducer) AggregateBoolean(p *BooleanPoint) {
	if _, ok := r.m[p.Value]; !ok {
		r.m[p.Value] = *p
	}
}

// Emit emits the distinct points that have been aggregated into the reducer.
func (r *BooleanDistinctReducer) Emit() []BooleanPoint {
	points := make([]BooleanPoint, 0, len(r.m))
	for _, p := range r.m {
		points = append(points, BooleanPoint{Time: p.Time, Value: p.Value})
	}
	sort.Sort(booleanPoints(points))
	return points
}

// BooleanElapsedReducer calculates the elapsed of the aggregated points.
type BooleanElapsedReducer struct {
	unitConversion int64
	prev           BooleanPoint
	curr           BooleanPoint
}

// NewBooleanElapsedReducer creates a new BooleanElapsedReducer.
func NewBooleanElapsedReducer(interval Interval) *BooleanElapsedReducer {
	return &BooleanElapsedReducer{
		unitConversion: int64(interval.Duration),
		prev:           BooleanPoint{Nil: true},
		curr:           BooleanPoint{Nil: true},
	}
}

// AggregateBoolean aggregates a point into the reducer and updates the current window.
func (r *BooleanElapsedReducer) AggregateBoolean(p *BooleanPoint) {
	r.prev = r.curr
	r.curr = *p
}

// Emit emits the elapsed of the reducer at the current point.
func (r *BooleanElapsedReducer) Emit() []IntegerPoint {
	if !r.prev.Nil {
		elapsed := (r.curr.Time - r.prev.Time) / r.unitConversion
		return []IntegerPoint{
			{Time: r.curr.Time, Value: elapsed},
		}
	}
	return nil
}

// BooleanSampleReducer implements a reservoir sampling to calculate a random subset of points
type BooleanSampleReducer struct {
	count int        // how many points we've iterated over
	rng   *rand.Rand // random number generator for each reducer

	points booleanPoints // the reservoir
}

// NewBooleanSampleReducer creates a new BooleanSampleReducer
func NewBooleanSampleReducer(size int) *BooleanSampleReducer {
	return &BooleanSampleReducer{
		rng:    rand.New(rand.NewSource(time.Now().UnixNano())), // seed with current time as suggested by https://golang.org/pkg/math/rand/
		points: make(booleanPoints, size),
	}
}

// AggregateBoolean aggregates a point into the reducer.
func (r *BooleanSampleReducer) AggregateBoolean(p *BooleanPoint) {
	r.count++
	// Fill the reservoir with the first n points
	if r.count-1 < len(r.points) {
		p.CopyTo(&r.points[r.count-1])
		return
	}

	// Generate a random integer between 1 and the count and
	// if that number is less than the length of the slice
	// replace the point at that index rnd with p.
	rnd := r.rng.Intn(r.count)
	if rnd < len(r.points) {
		p.CopyTo(&r.points[rnd])
	}
}

// Emit emits the reservoir sample as many points.
func (r *BooleanSampleReducer) Emit() []BooleanPoint {
	min := len(r.points)
	if r.count < min {
		min = r.count
	}
	pts := r.points[:min]
	sort.Sort(pts)
	return pts
}