forked from influxdata/influxdb
/
iterator.gen.go
7491 lines (6421 loc) · 197 KB
/
iterator.gen.go
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// Generated by tmpl
// https://github.com/benbjohnson/tmpl
//
// DO NOT EDIT!
// Source: iterator.gen.go.tmpl
package influxql
import (
"container/heap"
"encoding/binary"
"errors"
"fmt"
"io"
"log"
"sort"
"sync"
"time"
"github.com/gogo/protobuf/proto"
"github.com/influxdata/influxdb/influxql/internal"
)
// DefaultStatsInterval is the default value for IteratorEncoder.StatsInterval.
const DefaultStatsInterval = 10 * time.Second
// FloatIterator represents a stream of float points.
type FloatIterator interface {
Iterator
Next() *FloatPoint
}
// newFloatIterators converts a slice of Iterator to a slice of FloatIterator.
// Drop and closes any iterator in itrs that is not a FloatIterator and cannot
// be cast to a FloatIterator.
func newFloatIterators(itrs []Iterator) []FloatIterator {
a := make([]FloatIterator, 0, len(itrs))
for _, itr := range itrs {
switch itr := itr.(type) {
case FloatIterator:
a = append(a, itr)
case IntegerIterator:
a = append(a, &integerFloatCastIterator{input: itr})
default:
itr.Close()
}
}
return a
}
// bufFloatIterator represents a buffered FloatIterator.
type bufFloatIterator struct {
itr FloatIterator
buf *FloatPoint
}
// newBufFloatIterator returns a buffered FloatIterator.
func newBufFloatIterator(itr FloatIterator) *bufFloatIterator {
return &bufFloatIterator{itr: itr}
}
// Stats returns statistics from the input iterator.
func (itr *bufFloatIterator) Stats() IteratorStats { return itr.itr.Stats() }
// Close closes the underlying iterator.
func (itr *bufFloatIterator) Close() error { return itr.itr.Close() }
// peek returns the next point without removing it from the iterator.
func (itr *bufFloatIterator) peek() *FloatPoint {
p := itr.Next()
itr.unread(p)
return p
}
// peekTime returns the time of the next point.
// Returns zero time if no more points available.
func (itr *bufFloatIterator) peekTime() int64 {
p := itr.peek()
if p == nil {
return ZeroTime
}
return p.Time
}
// Next returns the current buffer, if exists, or calls the underlying iterator.
func (itr *bufFloatIterator) Next() *FloatPoint {
if itr.buf != nil {
buf := itr.buf
itr.buf = nil
return buf
}
return itr.itr.Next()
}
// NextInWindow returns the next value if it is between [startTime, endTime).
// If the next value is outside the range then it is moved to the buffer.
func (itr *bufFloatIterator) NextInWindow(startTime, endTime int64) *FloatPoint {
v := itr.Next()
if v == nil {
return nil
} else if v.Time < startTime || v.Time >= endTime {
itr.unread(v)
return nil
}
return v
}
// unread sets v to the buffer. It is read on the next call to Next().
func (itr *bufFloatIterator) unread(v *FloatPoint) { itr.buf = v }
// floatMergeIterator represents an iterator that combines multiple float iterators.
type floatMergeIterator struct {
inputs []FloatIterator
heap *floatMergeHeap
init bool
// Current iterator and window.
curr *floatMergeHeapItem
window struct {
name string
tags string
startTime int64
endTime int64
}
}
// newFloatMergeIterator returns a new instance of floatMergeIterator.
func newFloatMergeIterator(inputs []FloatIterator, opt IteratorOptions) *floatMergeIterator {
itr := &floatMergeIterator{
inputs: inputs,
heap: &floatMergeHeap{
items: make([]*floatMergeHeapItem, 0, len(inputs)),
opt: opt,
},
}
// Initialize heap items.
for _, input := range inputs {
// Wrap in buffer, ignore any inputs without anymore points.
bufInput := newBufFloatIterator(input)
// Append to the heap.
itr.heap.items = append(itr.heap.items, &floatMergeHeapItem{itr: bufInput})
}
return itr
}
// Stats returns an aggregation of stats from the underlying iterators.
func (itr *floatMergeIterator) Stats() IteratorStats {
var stats IteratorStats
for _, input := range itr.inputs {
stats.Add(input.Stats())
}
return stats
}
// Close closes the underlying iterators.
func (itr *floatMergeIterator) Close() error {
for _, input := range itr.inputs {
input.Close()
}
return nil
}
// Next returns the next point from the iterator.
func (itr *floatMergeIterator) Next() *FloatPoint {
// Initialize the heap. This needs to be done lazily on the first call to this iterator
// so that iterator initialization done through the Select() call returns quickly.
// Queries can only be interrupted after the Select() call completes so any operations
// done during iterator creation cannot be interrupted, which is why we do it here
// instead so an interrupt can happen while initializing the heap.
if !itr.init {
items := itr.heap.items
itr.heap.items = make([]*floatMergeHeapItem, 0, len(items))
for _, item := range items {
if item.itr.peek() == nil {
continue
}
itr.heap.items = append(itr.heap.items, item)
}
heap.Init(itr.heap)
itr.init = true
}
for {
// Retrieve the next iterator if we don't have one.
if itr.curr == nil {
if len(itr.heap.items) == 0 {
return nil
}
itr.curr = heap.Pop(itr.heap).(*floatMergeHeapItem)
// Read point and set current window.
p := itr.curr.itr.Next()
itr.window.name, itr.window.tags = p.Name, p.Tags.ID()
itr.window.startTime, itr.window.endTime = itr.heap.opt.Window(p.Time)
return p
}
// Read the next point from the current iterator.
p := itr.curr.itr.Next()
// If there are no more points then remove iterator from heap and find next.
if p == nil {
itr.curr = nil
continue
}
// Check if the point is inside of our current window.
inWindow := true
if itr.window.name != p.Name {
inWindow = false
} else if itr.window.tags != p.Tags.ID() {
inWindow = false
} else if itr.heap.opt.Ascending && p.Time >= itr.window.endTime {
inWindow = false
} else if !itr.heap.opt.Ascending && p.Time < itr.window.startTime {
inWindow = false
}
// If it's outside our window then push iterator back on the heap and find new iterator.
if !inWindow {
itr.curr.itr.unread(p)
heap.Push(itr.heap, itr.curr)
itr.curr = nil
continue
}
return p
}
}
// floatMergeHeap represents a heap of floatMergeHeapItems.
// Items are sorted by their next window and then by name/tags.
type floatMergeHeap struct {
opt IteratorOptions
items []*floatMergeHeapItem
}
func (h floatMergeHeap) Len() int { return len(h.items) }
func (h floatMergeHeap) Swap(i, j int) { h.items[i], h.items[j] = h.items[j], h.items[i] }
func (h floatMergeHeap) Less(i, j int) bool {
x, y := h.items[i].itr.peek(), h.items[j].itr.peek()
if h.opt.Ascending {
if x.Name != y.Name {
return x.Name < y.Name
} else if x.Tags.ID() != y.Tags.ID() {
return x.Tags.ID() < y.Tags.ID()
}
} else {
if x.Name != y.Name {
return x.Name > y.Name
} else if x.Tags.ID() != y.Tags.ID() {
return x.Tags.ID() > y.Tags.ID()
}
}
xt, _ := h.opt.Window(x.Time)
yt, _ := h.opt.Window(y.Time)
if h.opt.Ascending {
return xt < yt
}
return xt > yt
}
func (h *floatMergeHeap) Push(x interface{}) {
h.items = append(h.items, x.(*floatMergeHeapItem))
}
func (h *floatMergeHeap) Pop() interface{} {
old := h.items
n := len(old)
item := old[n-1]
h.items = old[0 : n-1]
return item
}
type floatMergeHeapItem struct {
itr *bufFloatIterator
}
// floatSortedMergeIterator is an iterator that sorts and merges multiple iterators into one.
type floatSortedMergeIterator struct {
inputs []FloatIterator
opt IteratorOptions
heap floatSortedMergeHeap
}
// newFloatSortedMergeIterator returns an instance of floatSortedMergeIterator.
func newFloatSortedMergeIterator(inputs []FloatIterator, opt IteratorOptions) Iterator {
itr := &floatSortedMergeIterator{
inputs: inputs,
heap: make(floatSortedMergeHeap, 0, len(inputs)),
opt: opt,
}
// Initialize heap.
for _, input := range inputs {
// Read next point.
p := input.Next()
if p == nil {
continue
}
// Append to the heap.
itr.heap = append(itr.heap, &floatSortedMergeHeapItem{point: p, itr: input, ascending: opt.Ascending})
}
heap.Init(&itr.heap)
return itr
}
// Stats returns an aggregation of stats from the underlying iterators.
func (itr *floatSortedMergeIterator) Stats() IteratorStats {
var stats IteratorStats
for _, input := range itr.inputs {
stats.Add(input.Stats())
}
return stats
}
// Close closes the underlying iterators.
func (itr *floatSortedMergeIterator) Close() error {
for _, input := range itr.inputs {
input.Close()
}
return nil
}
// Next returns the next points from the iterator.
func (itr *floatSortedMergeIterator) Next() *FloatPoint { return itr.pop() }
// pop returns the next point from the heap.
// Reads the next point from item's cursor and puts it back on the heap.
func (itr *floatSortedMergeIterator) pop() *FloatPoint {
if len(itr.heap) == 0 {
return nil
}
// Read the next item from the heap.
item := heap.Pop(&itr.heap).(*floatSortedMergeHeapItem)
// Copy the point for return.
p := item.point.Clone()
// Read the next item from the cursor. Push back to heap if one exists.
if item.point = item.itr.Next(); item.point != nil {
heap.Push(&itr.heap, item)
}
return p
}
// floatSortedMergeHeap represents a heap of floatSortedMergeHeapItems.
type floatSortedMergeHeap []*floatSortedMergeHeapItem
func (h floatSortedMergeHeap) Len() int { return len(h) }
func (h floatSortedMergeHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
func (h floatSortedMergeHeap) Less(i, j int) bool {
x, y := h[i].point, h[j].point
if h[i].ascending {
if x.Name != y.Name {
return x.Name < y.Name
} else if !x.Tags.Equals(&y.Tags) {
return x.Tags.ID() < y.Tags.ID()
}
return x.Time < y.Time
}
if x.Name != y.Name {
return x.Name > y.Name
} else if !x.Tags.Equals(&y.Tags) {
return x.Tags.ID() > y.Tags.ID()
}
return x.Time > y.Time
}
func (h *floatSortedMergeHeap) Push(x interface{}) {
*h = append(*h, x.(*floatSortedMergeHeapItem))
}
func (h *floatSortedMergeHeap) Pop() interface{} {
old := *h
n := len(old)
item := old[n-1]
*h = old[0 : n-1]
return item
}
type floatSortedMergeHeapItem struct {
point *FloatPoint
itr FloatIterator
ascending bool
}
// floatLimitIterator represents an iterator that limits points per group.
type floatLimitIterator struct {
input FloatIterator
opt IteratorOptions
n int
prev struct {
name string
tags Tags
}
}
// newFloatLimitIterator returns a new instance of floatLimitIterator.
func newFloatLimitIterator(input FloatIterator, opt IteratorOptions) *floatLimitIterator {
return &floatLimitIterator{
input: input,
opt: opt,
}
}
// Stats returns stats from the underlying iterator.
func (itr *floatLimitIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the underlying iterators.
func (itr *floatLimitIterator) Close() error { return itr.input.Close() }
// Next returns the next point from the iterator.
func (itr *floatLimitIterator) Next() *FloatPoint {
for {
p := itr.input.Next()
if p == nil {
return nil
}
// Reset window and counter if a new window is encountered.
if p.Name != itr.prev.name || !p.Tags.Equals(&itr.prev.tags) {
itr.prev.name = p.Name
itr.prev.tags = p.Tags
itr.n = 0
}
// Increment counter.
itr.n++
// Read next point if not beyond the offset.
if itr.n <= itr.opt.Offset {
continue
}
// Read next point if we're beyond the limit.
if itr.opt.Limit > 0 && (itr.n-itr.opt.Offset) > itr.opt.Limit {
// If there's no interval, no groups, and a single source then simply exit.
if itr.opt.Interval.IsZero() && len(itr.opt.Dimensions) == 0 && len(itr.opt.Sources) == 1 {
return nil
}
continue
}
return p
}
}
type floatFillIterator struct {
input *bufFloatIterator
prev *FloatPoint
startTime int64
endTime int64
auxFields []interface{}
done bool
opt IteratorOptions
window struct {
name string
tags Tags
time int64
}
}
func newFloatFillIterator(input FloatIterator, expr Expr, opt IteratorOptions) *floatFillIterator {
if opt.Fill == NullFill {
if expr, ok := expr.(*Call); ok && expr.Name == "count" {
opt.Fill = NumberFill
opt.FillValue = float64(0)
}
}
var startTime, endTime int64
if opt.Ascending {
startTime, _ = opt.Window(opt.StartTime)
_, endTime = opt.Window(opt.EndTime)
} else {
_, startTime = opt.Window(opt.EndTime)
endTime, _ = opt.Window(opt.StartTime)
}
var auxFields []interface{}
if len(opt.Aux) > 0 {
auxFields = make([]interface{}, len(opt.Aux))
}
itr := &floatFillIterator{
input: newBufFloatIterator(input),
startTime: startTime,
endTime: endTime,
auxFields: auxFields,
opt: opt,
}
p := itr.input.peek()
if p != nil {
itr.window.name, itr.window.tags = p.Name, p.Tags
itr.window.time = itr.startTime
} else {
itr.window.time = itr.endTime
}
return itr
}
func (itr *floatFillIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *floatFillIterator) Close() error { return itr.input.Close() }
func (itr *floatFillIterator) Next() *FloatPoint {
p := itr.input.Next()
// Check if the next point is outside of our window or is nil.
for p == nil || p.Name != itr.window.name || p.Tags.ID() != itr.window.tags.ID() {
// If we are inside of an interval, unread the point and continue below to
// constructing a new point.
if itr.opt.Ascending {
if itr.window.time < itr.endTime {
itr.input.unread(p)
p = nil
break
}
} else {
if itr.window.time >= itr.endTime {
itr.input.unread(p)
p = nil
break
}
}
// We are *not* in a current interval. If there is no next point,
// we are at the end of all intervals.
if p == nil {
return nil
}
// Set the new interval.
itr.window.name, itr.window.tags = p.Name, p.Tags
itr.window.time = itr.startTime
itr.prev = nil
break
}
// Check if the point is our next expected point.
if p == nil || p.Time > itr.window.time {
if p != nil {
itr.input.unread(p)
}
p = &FloatPoint{
Name: itr.window.name,
Tags: itr.window.tags,
Time: itr.window.time,
Aux: itr.auxFields,
}
switch itr.opt.Fill {
case NullFill:
p.Nil = true
case NumberFill:
p.Value = castToFloat(itr.opt.FillValue)
case PreviousFill:
if itr.prev != nil {
p.Value = itr.prev.Value
p.Nil = itr.prev.Nil
} else {
p.Nil = true
}
}
} else {
itr.prev = p
}
// Advance the expected time. Do not advance to a new window here
// as there may be lingering points with the same timestamp in the previous
// window.
if itr.opt.Ascending {
itr.window.time = p.Time + int64(itr.opt.Interval.Duration)
} else {
itr.window.time = p.Time - int64(itr.opt.Interval.Duration)
}
return p
}
// floatIntervalIterator represents a float implementation of IntervalIterator.
type floatIntervalIterator struct {
input FloatIterator
opt IteratorOptions
}
func newFloatIntervalIterator(input FloatIterator, opt IteratorOptions) *floatIntervalIterator {
return &floatIntervalIterator{input: input, opt: opt}
}
func (itr *floatIntervalIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *floatIntervalIterator) Close() error { return itr.input.Close() }
func (itr *floatIntervalIterator) Next() *FloatPoint {
p := itr.input.Next()
if p == nil {
return p
}
p.Time, _ = itr.opt.Window(p.Time)
return p
}
// floatInterruptIterator represents a float implementation of InterruptIterator.
type floatInterruptIterator struct {
input FloatIterator
closing <-chan struct{}
count int
}
func newFloatInterruptIterator(input FloatIterator, closing <-chan struct{}) *floatInterruptIterator {
return &floatInterruptIterator{input: input, closing: closing}
}
func (itr *floatInterruptIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *floatInterruptIterator) Close() error { return itr.input.Close() }
func (itr *floatInterruptIterator) Next() *FloatPoint {
// Only check if the channel is closed every 256 points. This
// intentionally checks on both 0 and 256 so that if the iterator
// has been interrupted before the first point is emitted it will
// not emit any points.
if itr.count&0x100 == 0 {
select {
case <-itr.closing:
return nil
default:
// Reset iterator count to zero and fall through to emit the next point.
itr.count = 0
}
}
// Increment the counter for every point read.
itr.count++
return itr.input.Next()
}
// floatAuxIterator represents a float implementation of AuxIterator.
type floatAuxIterator struct {
input *bufFloatIterator
output chan *FloatPoint
fields auxIteratorFields
background bool
}
func newFloatAuxIterator(input FloatIterator, seriesKeys SeriesList, opt IteratorOptions) *floatAuxIterator {
return &floatAuxIterator{
input: newBufFloatIterator(input),
output: make(chan *FloatPoint, 1),
fields: newAuxIteratorFields(seriesKeys, opt),
}
}
func (itr *floatAuxIterator) Background() {
itr.background = true
itr.Start()
go drainIterator(itr)
}
func (itr *floatAuxIterator) Start() { go itr.stream() }
func (itr *floatAuxIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *floatAuxIterator) Close() error { return itr.input.Close() }
func (itr *floatAuxIterator) Next() *FloatPoint { return <-itr.output }
func (itr *floatAuxIterator) Iterator(name string) Iterator { return itr.fields.iterator(name) }
func (itr *floatAuxIterator) CreateIterator(opt IteratorOptions) (Iterator, error) {
expr := opt.Expr
if expr == nil {
panic("unable to create an iterator with no expression from an aux iterator")
}
switch expr := expr.(type) {
case *VarRef:
return itr.Iterator(expr.Val), nil
default:
panic(fmt.Sprintf("invalid expression type for an aux iterator: %T", expr))
}
}
func (itr *floatAuxIterator) FieldDimensions(sources Sources) (fields, dimensions map[string]struct{}, err error) {
return nil, nil, errors.New("not implemented")
}
func (itr *floatAuxIterator) SeriesKeys(opt IteratorOptions) (SeriesList, error) {
return nil, errors.New("not implemented")
}
func (itr *floatAuxIterator) ExpandSources(sources Sources) (Sources, error) {
return nil, errors.New("not implemented")
}
func (itr *floatAuxIterator) stream() {
for {
// Read next point.
p := itr.input.Next()
if p == nil {
break
}
// Send point to output and to each field iterator.
itr.output <- p
if ok := itr.fields.send(p); !ok && itr.background {
break
}
}
close(itr.output)
itr.fields.close()
}
// floatChanIterator represents a new instance of floatChanIterator.
type floatChanIterator struct {
buf *FloatPoint
cond *sync.Cond
done bool
}
func (itr *floatChanIterator) Stats() IteratorStats { return IteratorStats{} }
func (itr *floatChanIterator) Close() error {
itr.cond.L.Lock()
// Mark the channel iterator as done and signal all waiting goroutines to start again.
itr.done = true
itr.cond.Broadcast()
// Do not defer the unlock so we don't create an unnecessary allocation.
itr.cond.L.Unlock()
return nil
}
func (itr *floatChanIterator) setBuf(name string, tags Tags, time int64, value interface{}) bool {
itr.cond.L.Lock()
defer itr.cond.L.Unlock()
// Wait for either the iterator to be done (so we don't have to set the value)
// or for the buffer to have been read and ready for another write.
for !itr.done && itr.buf != nil {
itr.cond.Wait()
}
// Do not set the value and return false to signal that the iterator is closed.
// Do this after the above wait as the above for loop may have exited because
// the iterator was closed.
if itr.done {
return false
}
switch v := value.(type) {
case float64:
itr.buf = &FloatPoint{Name: name, Tags: tags, Time: time, Value: v}
case int64:
itr.buf = &FloatPoint{Name: name, Tags: tags, Time: time, Value: float64(v)}
default:
itr.buf = &FloatPoint{Name: name, Tags: tags, Time: time, Nil: true}
}
// Signal to all waiting goroutines that a new value is ready to read.
itr.cond.Signal()
return true
}
func (itr *floatChanIterator) Next() *FloatPoint {
itr.cond.L.Lock()
// Wait until either a value is available in the buffer or
// the iterator is closed.
for !itr.done && itr.buf == nil {
itr.cond.Wait()
}
// Always read from the buffer if it exists, even if the iterator
// is closed. This prevents the last value from being truncated by
// the parent iterator.
p := itr.buf
itr.buf = nil
itr.cond.Signal()
// Do not defer the unlock so we don't create an unnecessary allocation.
itr.cond.L.Unlock()
return p
}
// floatReduceFloatIterator executes a reducer for every interval and buffers the result.
type floatReduceFloatIterator struct {
input *bufFloatIterator
create func() (FloatPointAggregator, FloatPointEmitter)
opt IteratorOptions
points []FloatPoint
}
// Stats returns stats from the input iterator.
func (itr *floatReduceFloatIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the iterator and all child iterators.
func (itr *floatReduceFloatIterator) Close() error { return itr.input.Close() }
// Next returns the minimum value for the next available interval.
func (itr *floatReduceFloatIterator) Next() *FloatPoint {
// Calculate next window if we have no more points.
if len(itr.points) == 0 {
itr.points = itr.reduce()
if len(itr.points) == 0 {
return nil
}
}
// Pop next point off the stack.
p := &itr.points[len(itr.points)-1]
itr.points = itr.points[:len(itr.points)-1]
return p
}
// floatReduceFloatPoint stores the reduced data for a name/tag combination.
type floatReduceFloatPoint struct {
Name string
Tags Tags
Aggregator FloatPointAggregator
Emitter FloatPointEmitter
}
// reduce executes fn once for every point in the next window.
// The previous value for the dimension is passed to fn.
func (itr *floatReduceFloatIterator) reduce() []FloatPoint {
// Calculate next window.
startTime, endTime := itr.opt.Window(itr.input.peekTime())
// Create points by tags.
m := make(map[string]*floatReduceFloatPoint)
for {
// Read next point.
curr := itr.input.NextInWindow(startTime, endTime)
if curr == nil {
break
} else if curr.Nil {
continue
}
tags := curr.Tags.Subset(itr.opt.Dimensions)
id := curr.Name
if len(tags.m) > 0 {
id += "\x00" + tags.ID()
}
// Retrieve the aggregator for this name/tag combination or create one.
rp := m[id]
if rp == nil {
aggregator, emitter := itr.create()
rp = &floatReduceFloatPoint{
Name: curr.Name,
Tags: tags,
Aggregator: aggregator,
Emitter: emitter,
}
m[id] = rp
}
rp.Aggregator.AggregateFloat(curr)
}
// Reverse sort points by name & tag.
keys := make([]string, 0, len(m))
for k := range m {
keys = append(keys, k)
}
sort.Sort(sort.Reverse(sort.StringSlice(keys)))
a := make([]FloatPoint, 0, len(m))
for _, k := range keys {
rp := m[k]
points := rp.Emitter.Emit()
for i := len(points) - 1; i >= 0; i-- {
points[i].Name = rp.Name
points[i].Tags = rp.Tags
// Set the points time to the interval time if the reducer didn't provide one.
if points[i].Time == ZeroTime {
points[i].Time = startTime
}
a = append(a, points[i])
}
}
return a
}
// floatStreamFloatIterator
type floatStreamFloatIterator struct {
input *bufFloatIterator
create func() (FloatPointAggregator, FloatPointEmitter)
opt IteratorOptions
m map[string]*floatReduceFloatPoint
points []FloatPoint
}
func newFloatStreamFloatIterator(input FloatIterator, createFn func() (FloatPointAggregator, FloatPointEmitter), opt IteratorOptions) *floatStreamFloatIterator {
return &floatStreamFloatIterator{
input: newBufFloatIterator(input),
create: createFn,
opt: opt,
m: make(map[string]*floatReduceFloatPoint),
}
}
// Stats returns stats from the input iterator.
func (itr *floatStreamFloatIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the iterator and all child iterators.
func (itr *floatStreamFloatIterator) Close() error { return itr.input.Close() }
// Next returns the next value for the stream iterator.
func (itr *floatStreamFloatIterator) Next() *FloatPoint {
// Calculate next window if we have no more points.
if len(itr.points) == 0 {
itr.points = itr.reduce()
if len(itr.points) == 0 {
return nil
}
}
// Pop next point off the stack.
p := &itr.points[len(itr.points)-1]
itr.points = itr.points[:len(itr.points)-1]
return p
}
// reduce creates and manages aggregators for every point from the input.
// After aggregating a point, it always tries to emit a value using the emitter.
func (itr *floatStreamFloatIterator) reduce() []FloatPoint {
for {
// Read next point.
curr := itr.input.Next()
if curr == nil {
return nil
} else if curr.Nil {
continue
}
tags := curr.Tags.Subset(itr.opt.Dimensions)
id := curr.Name
if len(tags.m) > 0 {
id += "\x00" + tags.ID()
}
// Retrieve the aggregator for this name/tag combination or create one.
rp := itr.m[id]
if rp == nil {
aggregator, emitter := itr.create()
rp = &floatReduceFloatPoint{
Name: curr.Name,
Tags: tags,
Aggregator: aggregator,
Emitter: emitter,
}
itr.m[id] = rp
}
rp.Aggregator.AggregateFloat(curr)
// Attempt to emit points from the aggregator.
points := rp.Emitter.Emit()
if len(points) == 0 {
continue
}
for i := range points {
points[i].Name = rp.Name
points[i].Tags = rp.Tags
}
return points
}
}
// floatExprIterator executes a function to modify an existing point
// for every output of the input iterator.
type floatExprIterator struct {
left *bufFloatIterator
right *bufFloatIterator
fn floatExprFunc
}
func (itr *floatExprIterator) Stats() IteratorStats {
stats := itr.left.Stats()
stats.Add(itr.right.Stats())
return stats
}
func (itr *floatExprIterator) Close() error {