influxdb/influxql/iterator.gen.go.tmpl

1477 lines
40 KiB
Cheetah

package influxql
import (
"container/heap"
"errors"
"encoding/binary"
"fmt"
"io"
"sort"
"sync"
"time"
"github.com/gogo/protobuf/proto"
internal "github.com/influxdata/influxdb/influxql/internal"
)
// DefaultStatsInterval is the default value for IteratorEncoder.StatsInterval.
const DefaultStatsInterval = 10 * time.Second
{{with $types := .}}{{range $k := $types}}
// {{$k.Name}}Iterator represents a stream of {{$k.name}} points.
type {{$k.Name}}Iterator interface {
Iterator
Next() (*{{$k.Name}}Point, error)
}
// new{{$k.Name}}Iterators converts a slice of Iterator to a slice of {{$k.Name}}Iterator.
// Drop and closes any iterator in itrs that is not a {{$k.Name}}Iterator and cannot
// be cast to a {{$k.Name}}Iterator.
func new{{$k.Name}}Iterators(itrs []Iterator) []{{$k.Name}}Iterator {
a := make([]{{$k.Name}}Iterator, 0, len(itrs))
for _, itr := range itrs {
switch itr := itr.(type) {
case {{$k.Name}}Iterator:
a = append(a, itr)
{{if eq .Name "Float"}}
case IntegerIterator:
a = append(a, &integerFloatCastIterator{input: itr})
{{end}}
default:
itr.Close()
}
}
return a
}
// buf{{$k.Name}}Iterator represents a buffered {{$k.Name}}Iterator.
type buf{{$k.Name}}Iterator struct {
itr {{$k.Name}}Iterator
buf *{{$k.Name}}Point
}
// newBuf{{$k.Name}}Iterator returns a buffered {{$k.Name}}Iterator.
func newBuf{{$k.Name}}Iterator(itr {{$k.Name}}Iterator) *buf{{$k.Name}}Iterator {
return &buf{{$k.Name}}Iterator{itr: itr}
}
// Stats returns statistics from the input iterator.
func (itr *buf{{$k.Name}}Iterator) Stats() IteratorStats { return itr.itr.Stats() }
// Close closes the underlying iterator.
func (itr *buf{{$k.Name}}Iterator) Close() error { return itr.itr.Close() }
// peek returns the next point without removing it from the iterator.
func (itr *buf{{$k.Name}}Iterator) peek() (*{{$k.Name}}Point, error) {
p, err := itr.Next()
if err != nil {
return nil, err
}
itr.unread(p)
return p, nil
}
// peekTime returns the time of the next point.
// Returns zero time if no more points available.
func (itr *buf{{$k.Name}}Iterator) peekTime() (int64, error) {
p, err := itr.peek()
if p == nil || err != nil {
return ZeroTime, err
}
return p.Time, nil
}
// Next returns the current buffer, if exists, or calls the underlying iterator.
func (itr *buf{{$k.Name}}Iterator) Next() (*{{$k.Name}}Point, error) {
buf := itr.buf
if buf != nil {
itr.buf = nil
return buf, nil
}
return itr.itr.Next()
}
// NextInWindow returns the next value if it is between [startTime, endTime).
// If the next value is outside the range then it is moved to the buffer.
func (itr *buf{{$k.Name}}Iterator) NextInWindow(startTime, endTime int64) (*{{$k.Name}}Point, error) {
v, err := itr.Next()
if v == nil || err != nil {
return nil, err
} else if t := v.Time; t >= endTime || t < startTime {
itr.unread(v)
return nil, nil
}
return v, nil
}
// unread sets v to the buffer. It is read on the next call to Next().
func (itr *buf{{$k.Name}}Iterator) unread(v *{{$k.Name}}Point) { itr.buf = v }
// {{$k.name}}MergeIterator represents an iterator that combines multiple {{$k.name}} iterators.
type {{$k.name}}MergeIterator struct {
inputs []{{$k.Name}}Iterator
heap *{{$k.name}}MergeHeap
init bool
// Current iterator and window.
curr *{{$k.name}}MergeHeapItem
window struct {
name string
tags string
startTime int64
endTime int64
}
}
// new{{$k.Name}}MergeIterator returns a new instance of {{$k.name}}MergeIterator.
func new{{$k.Name}}MergeIterator(inputs []{{$k.Name}}Iterator, opt IteratorOptions) *{{$k.name}}MergeIterator {
itr := &{{$k.name}}MergeIterator{
inputs: inputs,
heap: &{{$k.name}}MergeHeap{
items: make([]*{{$k.name}}MergeHeapItem, 0, len(inputs)),
opt: opt,
},
}
// Initialize heap items.
for _, input := range inputs {
// Wrap in buffer, ignore any inputs without anymore points.
bufInput := newBuf{{$k.Name}}Iterator(input)
// Append to the heap.
itr.heap.items = append(itr.heap.items, &{{$k.name}}MergeHeapItem{itr: bufInput})
}
return itr
}
// Stats returns an aggregation of stats from the underlying iterators.
func (itr *{{$k.name}}MergeIterator) Stats() IteratorStats {
var stats IteratorStats
for _, input := range itr.inputs {
stats.Add(input.Stats())
}
return stats
}
// Close closes the underlying iterators.
func (itr *{{$k.name}}MergeIterator) Close() error {
for _, input := range itr.inputs {
input.Close()
}
return nil
}
// Next returns the next point from the iterator.
func (itr *{{$k.name}}MergeIterator) Next() (*{{$k.Name}}Point, error) {
// Initialize the heap. This needs to be done lazily on the first call to this iterator
// so that iterator initialization done through the Select() call returns quickly.
// Queries can only be interrupted after the Select() call completes so any operations
// done during iterator creation cannot be interrupted, which is why we do it here
// instead so an interrupt can happen while initializing the heap.
if !itr.init {
items := itr.heap.items
itr.heap.items = make([]*{{$k.name}}MergeHeapItem, 0, len(items))
for _, item := range items {
if p, err := item.itr.peek(); err != nil {
return nil, err
} else if p == 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, nil
}
itr.curr = heap.Pop(itr.heap).(*{{$k.name}}MergeHeapItem)
// Read point and set current window.
p, err := itr.curr.itr.Next()
if err != nil {
return nil, err
}
itr.window.name, itr.window.tags = p.Name, p.Tags.ID()
itr.window.startTime, itr.window.endTime = itr.heap.opt.Window(p.Time)
return p, nil
}
// Read the next point from the current iterator.
p, err := itr.curr.itr.Next()
if err != nil {
return nil, err
}
// If there are no more points then remove iterator from heap and find next.
if p == nil {
itr.curr = nil
continue
}
// Check if the point is inside of our current window.
inWindow := true
if window := itr.window; window.name != p.Name {
inWindow = false
} else if window.tags != p.Tags.ID() {
inWindow = false
} else if opt := itr.heap.opt; opt.Ascending && p.Time >= window.endTime {
inWindow = false
} else if !opt.Ascending && p.Time < window.startTime {
inWindow = false
}
// If it's outside our window then push iterator back on the heap and find new iterator.
if !inWindow {
itr.curr.itr.unread(p)
heap.Push(itr.heap, itr.curr)
itr.curr = nil
continue
}
return p, nil
}
}
// {{$k.name}}MergeHeap represents a heap of {{$k.name}}MergeHeapItems.
// Items are sorted by their next window and then by name/tags.
type {{$k.name}}MergeHeap struct {
opt IteratorOptions
items []*{{$k.name}}MergeHeapItem
}
func (h {{$k.name}}MergeHeap) Len() int { return len(h.items) }
func (h {{$k.name}}MergeHeap) Swap(i, j int) { h.items[i], h.items[j] = h.items[j], h.items[i] }
func (h {{$k.name}}MergeHeap) Less(i, j int) bool {
x, err := h.items[i].itr.peek()
if err != nil {
return true
}
y, err := h.items[j].itr.peek()
if err != nil {
return false
}
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 *{{$k.name}}MergeHeap) Push(x interface{}) {
h.items = append(h.items, x.(*{{$k.name}}MergeHeapItem))
}
func (h *{{$k.name}}MergeHeap) Pop() interface{} {
old := h.items
n := len(old)
item := old[n-1]
h.items = old[0 : n-1]
return item
}
type {{$k.name}}MergeHeapItem struct {
itr *buf{{$k.Name}}Iterator
err error
}
// {{$k.name}}SortedMergeIterator is an iterator that sorts and merges multiple iterators into one.
type {{$k.name}}SortedMergeIterator struct {
inputs []{{$k.Name}}Iterator
opt IteratorOptions
heap {{$k.name}}SortedMergeHeap
init bool
point {{$k.Name}}Point
}
// new{{$k.Name}}SortedMergeIterator returns an instance of {{$k.name}}SortedMergeIterator.
func new{{$k.Name}}SortedMergeIterator(inputs []{{$k.Name}}Iterator, opt IteratorOptions) Iterator {
itr := &{{$k.name}}SortedMergeIterator{
inputs: inputs,
heap: make({{$k.name}}SortedMergeHeap, 0, len(inputs)),
opt: opt,
}
// Initialize heap items.
for _, input := range inputs {
// Append to the heap.
itr.heap = append(itr.heap, &{{$k.name}}SortedMergeHeapItem{itr: input, ascending: opt.Ascending})
}
return itr
}
// Stats returns an aggregation of stats from the underlying iterators.
func (itr *{{$k.name}}SortedMergeIterator) Stats() IteratorStats {
var stats IteratorStats
for _, input := range itr.inputs {
stats.Add(input.Stats())
}
return stats
}
// Close closes the underlying iterators.
func (itr *{{$k.name}}SortedMergeIterator) Close() error {
for _, input := range itr.inputs {
input.Close()
}
return nil
}
// Next returns the next points from the iterator.
func (itr *{{$k.name}}SortedMergeIterator) Next() (*{{$k.Name}}Point, error) { return itr.pop() }
// pop returns the next point from the heap.
// Reads the next point from item's cursor and puts it back on the heap.
func (itr *{{$k.name}}SortedMergeIterator) pop() (*{{$k.Name}}Point, error) {
// Initialize the heap. See the MergeIterator to see why this has to be done lazily.
if !itr.init {
items := itr.heap
itr.heap = make([]*{{$k.name}}SortedMergeHeapItem, 0, len(items))
for _, item := range items {
var err error
if item.point, err = item.itr.Next(); err != nil {
return nil, err
} else if item.point == nil {
continue
}
itr.heap = append(itr.heap, item)
}
heap.Init(&itr.heap)
itr.init = true
}
if len(itr.heap) == 0 {
return nil, nil
}
// Read the next item from the heap.
item := heap.Pop(&itr.heap).(*{{$k.name}}SortedMergeHeapItem)
if item.err != nil {
return nil, item.err
} else if item.point == nil {
return nil, nil
}
// Copy the point for return.
p := item.point.Clone()
// Read the next item from the cursor. Push back to heap if one exists.
if item.point, item.err = item.itr.Next(); item.point != nil {
heap.Push(&itr.heap, item)
}
return p, nil
}
// {{$k.name}}SortedMergeHeap represents a heap of {{$k.name}}SortedMergeHeapItems.
type {{$k.name}}SortedMergeHeap []*{{$k.name}}SortedMergeHeapItem
func (h {{$k.name}}SortedMergeHeap) Len() int { return len(h) }
func (h {{$k.name}}SortedMergeHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
func (h {{$k.name}}SortedMergeHeap) 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 *{{$k.name}}SortedMergeHeap) Push(x interface{}) {
*h = append(*h, x.(*{{$k.name}}SortedMergeHeapItem))
}
func (h *{{$k.name}}SortedMergeHeap) Pop() interface{} {
old := *h
n := len(old)
item := old[n-1]
*h = old[0 : n-1]
return item
}
type {{$k.name}}SortedMergeHeapItem struct {
point *{{$k.Name}}Point
err error
itr {{$k.Name}}Iterator
ascending bool
}
// {{$k.name}}ParallelIterator represents an iterator that pulls data in a separate goroutine.
type {{$k.name}}ParallelIterator struct {
input {{$k.Name}}Iterator
ch chan {{$k.name}}PointError
once sync.Once
closing chan struct{}
}
// new{{$k.Name}}ParallelIterator returns a new instance of {{$k.name}}ParallelIterator.
func new{{$k.Name}}ParallelIterator(input {{$k.Name}}Iterator) *{{$k.name}}ParallelIterator {
itr := &{{$k.name}}ParallelIterator{
input: input,
ch: make(chan {{$k.name}}PointError, 1),
closing: make(chan struct{}),
}
go itr.monitor()
return itr
}
// Stats returns stats from the underlying iterator.
func (itr *{{$k.name}}ParallelIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the underlying iterators.
func (itr *{{$k.name}}ParallelIterator) Close() error {
itr.once.Do(func() { close(itr.closing) })
return itr.input.Close()
}
// Next returns the next point from the iterator.
func (itr *{{$k.name}}ParallelIterator) Next() (*{{$k.Name}}Point, error) {
v, ok := <-itr.ch
if !ok {
return nil, io.EOF
}
return v.point, v.err
}
// monitor runs in a separate goroutine and actively pulls the next point.
func (itr *{{$k.name}}ParallelIterator) monitor() {
defer close(itr.ch)
for {
// Read next point.
p, err := itr.input.Next()
select {
case <-itr.closing:
return
case itr.ch <- {{$k.name}}PointError{point: p, err: err}:
}
}
}
type {{$k.name}}PointError struct {
point *{{$k.Name}}Point
err error
}
// {{$k.name}}LimitIterator represents an iterator that limits points per group.
type {{$k.name}}LimitIterator struct {
input {{$k.Name}}Iterator
opt IteratorOptions
n int
prev struct {
name string
tags Tags
}
}
// new{{$k.Name}}LimitIterator returns a new instance of {{$k.name}}LimitIterator.
func new{{$k.Name}}LimitIterator(input {{$k.Name}}Iterator, opt IteratorOptions) *{{$k.name}}LimitIterator {
return &{{$k.name}}LimitIterator{
input: input,
opt: opt,
}
}
// Stats returns stats from the underlying iterator.
func (itr *{{$k.name}}LimitIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the underlying iterators.
func (itr *{{$k.name}}LimitIterator) Close() error { return itr.input.Close() }
// Next returns the next point from the iterator.
func (itr *{{$k.name}}LimitIterator) Next() (*{{$k.Name}}Point, error) {
for {
p, err := itr.input.Next()
if p == nil || err != nil {
return nil, err
}
// 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, nil
}
continue
}
return p, nil
}
}
type {{$k.name}}FillIterator struct {
input *buf{{$k.Name}}Iterator
prev *{{$k.Name}}Point
startTime int64
endTime int64
auxFields []interface{}
init bool
opt IteratorOptions
window struct {
name string
tags Tags
time int64
}
}
func new{{$k.Name}}FillIterator(input {{$k.Name}}Iterator, expr Expr, opt IteratorOptions) *{{$k.name}}FillIterator {
if opt.Fill == NullFill {
if expr, ok := expr.(*Call); ok && expr.Name == "count" {
opt.Fill = NumberFill
opt.FillValue = {{$k.Zero}}
}
}
var startTime, endTime int64
if opt.Ascending {
startTime, _ = opt.Window(opt.StartTime)
endTime, _ = opt.Window(opt.EndTime)
} else {
startTime, _ = opt.Window(opt.EndTime)
endTime, _ = opt.Window(opt.StartTime)
}
var auxFields []interface{}
if len(opt.Aux) > 0 {
auxFields = make([]interface{}, len(opt.Aux))
}
return &{{$k.name}}FillIterator{
input: newBuf{{$k.Name}}Iterator(input),
startTime: startTime,
endTime: endTime,
auxFields: auxFields,
opt: opt,
}
}
func (itr *{{$k.name}}FillIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *{{$k.name}}FillIterator) Close() error { return itr.input.Close() }
func (itr *{{$k.name}}FillIterator) Next() (*{{$k.Name}}Point, error) {
if !itr.init {
p, err := itr.input.peek()
if p == nil || err != nil {
return nil, err
}
itr.window.name, itr.window.tags = p.Name, p.Tags
itr.window.time = itr.startTime
itr.init = true
}
p, err := itr.input.Next()
if err != nil {
return nil, err
}
// Check if the next point is outside of our window or is nil.
for p == nil || p.Name != itr.window.name || p.Tags.ID() != itr.window.tags.ID() {
// If we are inside of an interval, unread the point and continue below to
// constructing a new point.
if itr.opt.Ascending {
if itr.window.time <= itr.endTime {
itr.input.unread(p)
p = nil
break
}
} else {
if itr.window.time >= itr.endTime {
itr.input.unread(p)
p = nil
break
}
}
// We are *not* in a current interval. If there is no next point,
// we are at the end of all intervals.
if p == nil {
return nil, nil
}
// Set the new interval.
itr.window.name, itr.window.tags = p.Name, p.Tags
itr.window.time = itr.startTime
itr.prev = nil
break
}
// Check if the point is our next expected point.
if p == nil || (itr.opt.Ascending && p.Time > itr.window.time) || (!itr.opt.Ascending && p.Time < itr.window.time) {
if p != nil {
itr.input.unread(p)
}
p = &{{$k.Name}}Point{
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 = castTo{{$k.Name}}(itr.opt.FillValue)
case PreviousFill:
if itr.prev != nil {
p.Value = itr.prev.Value
p.Nil = itr.prev.Nil
} else {
p.Nil = true
}
}
} else {
itr.prev = p
}
// Advance the expected time. Do not advance to a new window here
// as there may be lingering points with the same timestamp in the previous
// window.
if itr.opt.Ascending {
itr.window.time = p.Time + int64(itr.opt.Interval.Duration)
} else {
itr.window.time = p.Time - int64(itr.opt.Interval.Duration)
}
return p, nil
}
// {{$k.name}}IntervalIterator represents a {{$k.name}} implementation of IntervalIterator.
type {{$k.name}}IntervalIterator struct {
input {{$k.Name}}Iterator
opt IteratorOptions
}
func new{{$k.Name}}IntervalIterator(input {{$k.Name}}Iterator, opt IteratorOptions) *{{$k.name}}IntervalIterator {
return &{{$k.name}}IntervalIterator{input: input, opt: opt}
}
func (itr *{{$k.name}}IntervalIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *{{$k.name}}IntervalIterator) Close() error { return itr.input.Close() }
func (itr *{{$k.name}}IntervalIterator) Next() (*{{$k.Name}}Point, error) {
p, err := itr.input.Next()
if p == nil || err != nil {
return nil, err
}
p.Time, _ = itr.opt.Window(p.Time)
return p, nil
}
// {{$k.name}}InterruptIterator represents a {{$k.name}} implementation of InterruptIterator.
type {{$k.name}}InterruptIterator struct {
input {{$k.Name}}Iterator
closing <-chan struct{}
count int
}
func new{{$k.Name}}InterruptIterator(input {{$k.Name}}Iterator, closing <-chan struct{}) *{{$k.name}}InterruptIterator {
return &{{$k.name}}InterruptIterator{input: input, closing: closing}
}
func (itr *{{$k.name}}InterruptIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *{{$k.name}}InterruptIterator) Close() error { return itr.input.Close() }
func (itr *{{$k.name}}InterruptIterator) Next() (*{{$k.Name}}Point, error) {
// Only check if the channel is closed every N points. This
// intentionally checks on both 0 and N so that if the iterator
// has been interrupted before the first point is emitted it will
// not emit any points.
if itr.count & 0xFF == 0xFF {
select {
case <-itr.closing:
return nil, nil
default:
// Reset iterator count to zero and fall through to emit the next point.
itr.count = 0
}
}
// Increment the counter for every point read.
itr.count++
return itr.input.Next()
}
// {{$k.name}}CloseInterruptIterator represents a {{$k.name}} implementation of CloseInterruptIterator.
type {{$k.name}}CloseInterruptIterator struct {
input {{$k.Name}}Iterator
closing <-chan struct{}
done chan struct{}
once sync.Once
}
func new{{$k.Name}}CloseInterruptIterator(input {{$k.Name}}Iterator, closing <-chan struct{}) *{{$k.name}}CloseInterruptIterator {
itr := &{{$k.name}}CloseInterruptIterator{
input: input,
closing: closing,
done: make(chan struct{}),
}
go itr.monitor()
return itr
}
func (itr *{{$k.name}}CloseInterruptIterator) monitor() {
select {
case <-itr.closing:
itr.Close()
case <-itr.done:
}
}
func (itr *{{$k.name}}CloseInterruptIterator) Stats() IteratorStats {
return itr.input.Stats()
}
func (itr *{{$k.name}}CloseInterruptIterator) Close() error {
itr.once.Do(func() {
close(itr.done)
itr.input.Close()
})
return nil
}
func (itr *{{$k.name}}CloseInterruptIterator) Next() (*{{$k.Name}}Point, error) {
p, err := itr.input.Next()
if err != nil {
// Check if the iterator was closed.
select {
case <-itr.done:
return nil, nil
default:
return nil, err
}
}
return p, nil
}
// aux{{$k.Name}}Point represents a combination of a point and an error for the AuxIterator.
type aux{{$k.Name}}Point struct {
point *{{$k.Name}}Point
err error
}
// {{$k.name}}AuxIterator represents a {{$k.name}} implementation of AuxIterator.
type {{$k.name}}AuxIterator struct {
input *buf{{$k.Name}}Iterator
output chan aux{{$k.Name}}Point
fields auxIteratorFields
background bool
}
func new{{$k.Name}}AuxIterator(input {{$k.Name}}Iterator, opt IteratorOptions) *{{$k.name}}AuxIterator {
return &{{$k.name}}AuxIterator{
input: newBuf{{$k.Name}}Iterator(input),
output: make(chan aux{{$k.Name}}Point, 1),
fields: newAuxIteratorFields(opt),
}
}
func (itr *{{$k.name}}AuxIterator) Background() {
itr.background = true
itr.Start()
go DrainIterator(itr)
}
func (itr *{{$k.name}}AuxIterator) Start() { go itr.stream() }
func (itr *{{$k.name}}AuxIterator) Stats() IteratorStats { return itr.input.Stats() }
func (itr *{{$k.name}}AuxIterator) Close() error { return itr.input.Close() }
func (itr *{{$k.name}}AuxIterator) Next() (*{{$k.Name}}Point, error) {
p := <-itr.output
return p.point, p.err
}
func (itr *{{$k.name}}AuxIterator) Iterator(name string, typ DataType) Iterator { return itr.fields.iterator(name, typ) }
func (itr *{{$k.name}}AuxIterator) 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, expr.Type), nil
default:
panic(fmt.Sprintf("invalid expression type for an aux iterator: %T", expr))
}
}
func (itr *{{$k.name}}AuxIterator) FieldDimensions(sources Sources) (fields map[string]DataType, dimensions map[string]struct{}, err error) {
return nil, nil, errors.New("not implemented")
}
func (itr *{{$k.name}}AuxIterator) ExpandSources(sources Sources) (Sources, error) {
return nil, errors.New("not implemented")
}
func (itr *{{.name}}AuxIterator) stream() {
for {
// Read next point.
p, err := itr.input.Next()
if err != nil {
itr.output <- aux{{$k.Name}}Point{err: err}
itr.fields.sendError(err)
break
} else if p == nil {
break
}
// Send point to output and to each field iterator.
itr.output <- aux{{$k.Name}}Point{point: p}
if ok := itr.fields.send(p); !ok && itr.background {
break
}
}
close(itr.output)
itr.fields.close()
}
// {{$k.name}}ChanIterator represents a new instance of {{$k.name}}ChanIterator.
type {{$k.name}}ChanIterator struct {
buf struct {
i int
filled bool
points [2]{{$k.Name}}Point
}
err error
cond *sync.Cond
done bool
}
func (itr *{{$k.name}}ChanIterator) Stats() IteratorStats { return IteratorStats{} }
func (itr *{{$k.name}}ChanIterator) 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 *{{$k.name}}ChanIterator) setBuf(name string, tags Tags, time int64, value interface{}) bool {
itr.cond.L.Lock()
defer itr.cond.L.Unlock()
// Wait for either the iterator to be done (so we don't have to set the value)
// or for the buffer to have been read and ready for another write.
for !itr.done && itr.buf.filled {
itr.cond.Wait()
}
// Do not set the value and return false to signal that the iterator is closed.
// Do this after the above wait as the above for loop may have exited because
// the iterator was closed.
if itr.done {
return false
}
switch v := value.(type) {
case {{$k.Type}}:
itr.buf.points[itr.buf.i] = {{$k.Name}}Point{Name: name, Tags: tags, Time: time, Value: v}
{{if eq $k.Name "Float"}}
case int64:
itr.buf.points[itr.buf.i] = {{$k.Name}}Point{Name: name, Tags: tags, Time: time, Value: float64(v)}
{{end}}
default:
itr.buf.points[itr.buf.i] = {{$k.Name}}Point{Name: name, Tags: tags, Time: time, Nil: true}
}
itr.buf.filled = true
// Signal to all waiting goroutines that a new value is ready to read.
itr.cond.Signal()
return true
}
func (itr *{{$k.name}}ChanIterator) setErr(err error) {
itr.cond.L.Lock()
defer itr.cond.L.Unlock()
itr.err = err
// Signal to all waiting goroutines that a new value is ready to read.
itr.cond.Signal()
}
func (itr *{{$k.name}}ChanIterator) Next() (*{{$k.Name}}Point, error) {
itr.cond.L.Lock()
defer itr.cond.L.Unlock()
// Check for an error and return one if there.
if itr.err != nil {
return nil, itr.err
}
// Wait until either a value is available in the buffer or
// the iterator is closed.
for !itr.done && !itr.buf.filled {
itr.cond.Wait()
}
// Return nil once the channel is done and the buffer is empty.
if itr.done && !itr.buf.filled {
return nil, nil
}
// 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.points[itr.buf.i]
itr.buf.i = (itr.buf.i + 1) % len(itr.buf.points)
itr.buf.filled = false
itr.cond.Signal()
return p, nil
}
{{range $v := $types}}
// {{$k.name}}Reduce{{$v.Name}}Iterator executes a reducer for every interval and buffers the result.
type {{$k.name}}Reduce{{$v.Name}}Iterator struct {
input *buf{{$k.Name}}Iterator
create func() ({{$k.Name}}PointAggregator, {{$v.Name}}PointEmitter)
opt IteratorOptions
points []{{$v.Name}}Point
}
// Stats returns stats from the input iterator.
func (itr *{{$k.name}}Reduce{{$v.Name}}Iterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the iterator and all child iterators.
func (itr *{{$k.name}}Reduce{{$v.Name}}Iterator) Close() error { return itr.input.Close() }
// Next returns the minimum value for the next available interval.
func (itr *{{$k.name}}Reduce{{$v.Name}}Iterator) Next() (*{{$v.Name}}Point, error) {
// Calculate next window if we have no more points.
if len(itr.points) == 0 {
var err error
itr.points, err = itr.reduce()
if len(itr.points) == 0 {
return nil, err
}
}
// Pop next point off the stack.
p := &itr.points[len(itr.points)-1]
itr.points = itr.points[:len(itr.points)-1]
return p, nil
}
// {{$k.name}}Reduce{{$v.Name}}Point stores the reduced data for a name/tag combination.
type {{$k.name}}Reduce{{$v.Name}}Point struct {
Name string
Tags Tags
Aggregator {{$k.Name}}PointAggregator
Emitter {{$v.Name}}PointEmitter
}
// reduce executes fn once for every point in the next window.
// The previous value for the dimension is passed to fn.
func (itr *{{$k.name}}Reduce{{$v.Name}}Iterator) reduce() ([]{{$v.Name}}Point, error) {
// Calculate next window.
t, err := itr.input.peekTime()
if err != nil {
return nil, err
}
startTime, endTime := itr.opt.Window(t)
// Create points by tags.
m := make(map[string]*{{$k.name}}Reduce{{$v.Name}}Point)
for {
// Read next point.
curr, err := itr.input.NextInWindow(startTime, endTime)
if err != nil {
return nil, err
} else if curr == nil {
break
} else if curr.Nil {
continue
}
tags := curr.Tags.Subset(itr.opt.Dimensions)
id := curr.Name
if len(tags.m) > 0 {
id += "\x00" + tags.ID()
}
// Retrieve the aggregator for this name/tag combination or create one.
rp := m[id]
if rp == nil {
aggregator, emitter := itr.create()
rp = &{{$k.name}}Reduce{{.Name}}Point{
Name: curr.Name,
Tags: tags,
Aggregator: aggregator,
Emitter: emitter,
}
m[id] = rp
}
rp.Aggregator.Aggregate{{$k.Name}}(curr)
}
// Reverse sort points by name & tag.
keys := make([]string, 0, len(m))
for k := range m {
keys = append(keys, k)
}
if len(keys) > 1 {
sort.Sort(reverseStringSlice(keys))
}
a := make([]{{$v.Name}}Point, 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, nil
}
// {{$k.name}}Stream{{$v.Name}}Iterator streams inputs into the iterator and emits points gradually.
type {{$k.name}}Stream{{$v.Name}}Iterator struct {
input *buf{{$k.Name}}Iterator
create func() ({{$k.Name}}PointAggregator, {{$v.Name}}PointEmitter)
opt IteratorOptions
m map[string]*{{$k.name}}Reduce{{$v.Name}}Point
points []{{$v.Name}}Point
}
// new{{$k.Name}}Stream{{$v.Name}}Iterator returns a new instance of {{$k.name}}Stream{{$v.Name}}Iterator.
func new{{$k.Name}}Stream{{$v.Name}}Iterator(input {{$k.Name}}Iterator, createFn func() ({{$k.Name}}PointAggregator, {{$v.Name}}PointEmitter), opt IteratorOptions) *{{$k.name}}Stream{{$v.Name}}Iterator {
return &{{$k.name}}Stream{{$v.Name}}Iterator{
input: newBuf{{$k.Name}}Iterator(input),
create: createFn,
opt: opt,
m: make(map[string]*{{$k.name}}Reduce{{$v.Name}}Point),
}
}
// Stats returns stats from the input iterator.
func (itr *{{$k.name}}Stream{{$v.Name}}Iterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the iterator and all child iterators.
func (itr *{{$k.name}}Stream{{$v.Name}}Iterator) Close() error { return itr.input.Close() }
// Next returns the next value for the stream iterator.
func (itr *{{$k.name}}Stream{{$v.Name}}Iterator) Next() (*{{$v.Name}}Point, error) {
// Calculate next window if we have no more points.
if len(itr.points) == 0 {
var err error
itr.points, err = itr.reduce()
if len(itr.points) == 0 {
return nil, err
}
}
// Pop next point off the stack.
p := &itr.points[len(itr.points)-1]
itr.points = itr.points[:len(itr.points)-1]
return p, nil
}
// reduce creates and manages aggregators for every point from the input.
// After aggregating a point, it always tries to emit a value using the emitter.
func (itr *{{$k.name}}Stream{{$v.Name}}Iterator) reduce() ([]{{$v.Name}}Point, error) {
for {
// Read next point.
curr, err := itr.input.Next()
if curr == nil || err != nil {
return nil, err
} 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 = &{{$k.name}}Reduce{{.Name}}Point{
Name: curr.Name,
Tags: tags,
Aggregator: aggregator,
Emitter: emitter,
}
itr.m[id] = rp
}
rp.Aggregator.Aggregate{{$k.Name}}(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, nil
}
}
// {{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprIterator executes a function to modify an existing point
// for every output of the input iterator.
type {{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprIterator struct {
left *buf{{$k.Name}}Iterator
right *buf{{$k.Name}}Iterator
fn {{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprFunc
}
func (itr *{{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprIterator) Stats() IteratorStats {
stats := itr.left.Stats()
stats.Add(itr.right.Stats())
return stats
}
func (itr *{{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprIterator) Close() error {
itr.left.Close()
itr.right.Close()
return nil
}
func (itr *{{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprIterator) Next() (*{{$v.Name}}Point, error) {
a, err := itr.left.Next()
if err != nil {
return nil, err
}
b, err := itr.right.Next()
if err != nil {
return nil, err
} else if a == nil && b == nil {
return nil, nil
}
return itr.fn(a, b), nil
}
// {{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprFunc creates or modifies a point by combining two
// points. The point passed in may be modified and returned rather than
// allocating a new point if possible. One of the points may be nil, but at
// least one of the points will be non-nil.
type {{$k.name}}{{if ne $k.Name $v.Name}}{{$v.Name}}{{end}}ExprFunc func(a *{{$k.Name}}Point, b *{{$k.Name}}Point) *{{$v.Name}}Point
{{end}}
// {{$k.name}}TransformIterator executes a function to modify an existing point for every
// output of the input iterator.
type {{$k.name}}TransformIterator struct {
input {{$k.Name}}Iterator
fn {{$k.name}}TransformFunc
}
// Stats returns stats from the input iterator.
func (itr *{{$k.name}}TransformIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the iterator and all child iterators.
func (itr *{{$k.name}}TransformIterator) Close() error { return itr.input.Close() }
// Next returns the minimum value for the next available interval.
func (itr *{{$k.name}}TransformIterator) Next() (*{{$k.Name}}Point, error) {
p, err := itr.input.Next()
if err != nil {
return nil, err
} else if p != nil {
p = itr.fn(p)
}
return p, nil
}
// {{$k.name}}TransformFunc creates or modifies a point.
// The point passed in may be modified and returned rather than allocating a
// new point if possible.
type {{$k.name}}TransformFunc func(p *{{$k.Name}}Point) *{{$k.Name}}Point
// {{$k.name}}BoolTransformIterator executes a function to modify an existing point for every
// output of the input iterator.
type {{$k.name}}BoolTransformIterator struct {
input {{$k.Name}}Iterator
fn {{$k.name}}BoolTransformFunc
}
// Stats returns stats from the input iterator.
func (itr *{{$k.name}}BoolTransformIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the iterator and all child iterators.
func (itr *{{$k.name}}BoolTransformIterator) Close() error { return itr.input.Close() }
// Next returns the minimum value for the next available interval.
func (itr *{{$k.name}}BoolTransformIterator) Next() (*BooleanPoint, error) {
p, err := itr.input.Next()
if err != nil {
return nil, err
} else if p != nil {
return itr.fn(p), nil
}
return nil, nil
}
// {{$k.name}}BoolTransformFunc creates or modifies a point.
// The point passed in may be modified and returned rather than allocating a
// new point if possible.
type {{$k.name}}BoolTransformFunc func(p *{{$k.Name}}Point) *BooleanPoint
// {{$k.name}}DedupeIterator only outputs unique points.
// This differs from the DistinctIterator in that it compares all aux fields too.
// This iterator is relatively inefficient and should only be used on small
// datasets such as meta query results.
type {{$k.name}}DedupeIterator struct {
input {{$k.Name}}Iterator
m map[string]struct{} // lookup of points already sent
}
// new{{$k.Name}}DedupeIterator returns a new instance of {{$k.name}}DedupeIterator.
func new{{$k.Name}}DedupeIterator(input {{$k.Name}}Iterator) *{{$k.name}}DedupeIterator {
return &{{$k.name}}DedupeIterator{
input: input,
m: make(map[string]struct{}),
}
}
// Stats returns stats from the input iterator.
func (itr *{{$k.name}}DedupeIterator) Stats() IteratorStats { return itr.input.Stats() }
// Close closes the iterator and all child iterators.
func (itr *{{$k.name}}DedupeIterator) Close() error { return itr.input.Close() }
// Next returns the next unique point from the input iterator.
func (itr *{{$k.name}}DedupeIterator) Next() (*{{$k.Name}}Point, error) {
for {
// Read next point.
p, err := itr.input.Next()
if p == nil || err != nil {
return nil, err
}
// Serialize to bytes to store in lookup.
buf, err := proto.Marshal(encode{{$k.Name}}Point(p))
if err != nil {
return nil, err
}
// If the point has already been output then move to the next point.
if _, ok := itr.m[string(buf)]; ok {
continue
}
// Otherwise mark it as emitted and return point.
itr.m[string(buf)] = struct{}{}
return p, nil
}
}
// {{$k.name}}ReaderIterator represents an iterator that streams from a reader.
type {{$k.name}}ReaderIterator struct {
r io.Reader
dec *{{$k.Name}}PointDecoder
}
// new{{$k.Name}}ReaderIterator returns a new instance of {{$k.name}}ReaderIterator.
func new{{$k.Name}}ReaderIterator(r io.Reader, stats IteratorStats) *{{$k.name}}ReaderIterator {
dec := New{{$k.Name}}PointDecoder(r)
dec.stats = stats
return &{{$k.name}}ReaderIterator{
r: r,
dec: dec,
}
}
// Stats returns stats about points processed.
func (itr *{{$k.name}}ReaderIterator) Stats() IteratorStats { return itr.dec.stats }
// Close closes the underlying reader, if applicable.
func (itr *{{$k.name}}ReaderIterator) Close() error {
if r, ok := itr.r.(io.ReadCloser); ok {
return r.Close()
}
return nil
}
// Next returns the next point from the iterator.
func (itr *{{$k.name}}ReaderIterator) Next() (*{{$k.Name}}Point, error) {
// OPTIMIZE(benbjohnson): Reuse point on iterator.
// Unmarshal next point.
p := &{{$k.Name}}Point{}
if err := itr.dec.Decode{{$k.Name}}Point(p); err == io.EOF {
return nil, nil
} else if err != nil {
return nil, err
}
return p, nil
}
{{end}}
// IteratorEncoder is an encoder for encoding an iterator's points to w.
type IteratorEncoder struct {
w io.Writer
// Frequency with which stats are emitted.
StatsInterval time.Duration
}
// NewIteratorEncoder encodes an iterator's points to w.
func NewIteratorEncoder(w io.Writer) *IteratorEncoder {
return &IteratorEncoder{
w: w,
StatsInterval: DefaultStatsInterval,
}
}
// Encode encodes and writes all of itr's points to the underlying writer.
func (enc *IteratorEncoder) EncodeIterator(itr Iterator) error {
switch itr := itr.(type) {
case FloatIterator:
return enc.encodeFloatIterator(itr)
case IntegerIterator:
return enc.encodeIntegerIterator(itr)
case StringIterator:
return enc.encodeStringIterator(itr)
case BooleanIterator:
return enc.encodeBooleanIterator(itr)
default:
panic(fmt.Sprintf("unsupported iterator for encoder: %T", itr))
}
}
{{range .}}
// encode{{.Name}}Iterator encodes all points from itr to the underlying writer.
func (enc *IteratorEncoder) encode{{.Name}}Iterator(itr {{.Name}}Iterator) error {
ticker := time.NewTicker(enc.StatsInterval)
defer ticker.Stop()
// Emit initial stats.
if err := enc.encodeStats(itr.Stats()); err != nil {
return err
}
// Continually stream points from the iterator into the encoder.
penc := New{{.Name}}PointEncoder(enc.w)
for {
// Emit stats periodically.
select {
case <-ticker.C:
if err := enc.encodeStats(itr.Stats()); err != nil {
return err
}
default:
}
// Retrieve the next point from the iterator.
p, err := itr.Next()
if err != nil {
return err
} else if p == nil {
break
}
// Write the point to the point encoder.
if err := penc.Encode{{.Name}}Point(p); err != nil {
return err
}
}
// Emit final stats.
if err := enc.encodeStats(itr.Stats()); err != nil {
return err
}
return nil
}
{{end}}
// encode a stats object in the point stream.
func (enc *IteratorEncoder) encodeStats(stats IteratorStats) error {
buf, err := proto.Marshal(&internal.Point{
Name: proto.String(""),
Tags: proto.String(""),
Time: proto.Int64(0),
Nil: proto.Bool(false),
Stats: encodeIteratorStats(&stats),
})
if err != nil {
return err
}
if err := binary.Write(enc.w, binary.BigEndian, uint32(len(buf))); err != nil {
return err
}
if _, err := enc.w.Write(buf); err != nil {
return err
}
return nil
}
{{end}}