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updates

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This commit is contained in:
Will Charczuk 2017-04-29 16:18:09 -07:00
parent 255390c710
commit 472d04b3fa
14 changed files with 397 additions and 381 deletions
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10
annotation_series.go
View file

@ -3,6 +3,8 @@ package chart
import (
"fmt"
"math"
util "github.com/wcharczuk/go-chart/util"
)
// AnnotationSeries is a series of labels on the chart.
@ -55,10 +57,10 @@ func (as AnnotationSeries) Measure(r Renderer, canvasBox Box, xrange, yrange Ran
lx := canvasBox.Left + xrange.Translate(a.XValue)
ly := canvasBox.Bottom - yrange.Translate(a.YValue)
ab := Draw.MeasureAnnotation(r, canvasBox, style, lx, ly, a.Label)
box.Top = Math.MinInt(box.Top, ab.Top)
box.Left = Math.MinInt(box.Left, ab.Left)
box.Right = Math.MaxInt(box.Right, ab.Right)
box.Bottom = Math.MaxInt(box.Bottom, ab.Bottom)
box.Top = util.Math.MinInt(box.Top, ab.Top)
box.Left = util.Math.MinInt(box.Left, ab.Left)
box.Right = util.Math.MaxInt(box.Right, ab.Right)
box.Bottom = util.Math.MaxInt(box.Bottom, ab.Bottom)
}
}
return box

5
bar_chart.go
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@ -7,6 +7,7 @@ import (
"math"
"github.com/golang/freetype/truetype"
util "github.com/wcharczuk/go-chart/util"
)
// BarChart is a chart that draws bars on a range.
@ -368,7 +369,7 @@ func (bc BarChart) getAdjustedCanvasBox(r Renderer, canvasBox Box, yrange Range,
lines := Text.WrapFit(r, bar.Label, barLabelBox.Width(), axisStyle)
linesBox := Text.MeasureLines(r, lines, axisStyle)
xaxisHeight = Math.MinInt(linesBox.Height()+(2*DefaultXAxisMargin), xaxisHeight)
xaxisHeight = util.Math.MinInt(linesBox.Height()+(2*DefaultXAxisMargin), xaxisHeight)
}
}
@ -435,7 +436,7 @@ func (bc BarChart) styleDefaultsTitle() Style {
}
func (bc BarChart) getTitleFontSize() float64 {
effectiveDimension := Math.MinInt(bc.GetWidth(), bc.GetHeight())
effectiveDimension := util.Math.MinInt(bc.GetWidth(), bc.GetHeight())
if effectiveDimension >= 2048 {
return 48
} else if effectiveDimension >= 1024 {

14
bollinger_band_series.go
View file

@ -1,6 +1,10 @@
package chart
import "fmt"
import (
"fmt"
"github.com/wcharczuk/go-chart/util"
)
// BollingerBandsSeries draws bollinger bands for an inner series.
// Bollinger bands are defined by two lines, one at SMA+k*stddev, one at SMA-k*stdev.
@ -13,7 +17,7 @@ type BollingerBandsSeries struct {
K float64
InnerSeries ValuesProvider
valueBuffer *ValueBuffer
valueBuffer *util.ValueBuffer
}
// GetName returns the name of the time series.
@ -63,7 +67,7 @@ func (bbs *BollingerBandsSeries) GetBoundedValues(index int) (x, y1, y2 float64)
return
}
if bbs.valueBuffer == nil || index == 0 {
bbs.valueBuffer = NewValueBufferWithCapacity(bbs.GetPeriod())
bbs.valueBuffer = util.NewValueBufferWithCapacity(bbs.GetPeriod())
}
if bbs.valueBuffer.Len() >= bbs.GetPeriod() {
bbs.valueBuffer.Dequeue()
@ -72,8 +76,8 @@ func (bbs *BollingerBandsSeries) GetBoundedValues(index int) (x, y1, y2 float64)
bbs.valueBuffer.Enqueue(py)
x = px
ay := Sequence{bbs.valueBuffer}.Average()
std := Sequence{bbs.valueBuffer}.StdDev()
ay := util.Sequence{bbs.valueBuffer}.Average()
std := util.Sequence{bbs.valueBuffer}.StdDev()
y1 = ay + (bbs.GetK() * std)
y2 = ay - (bbs.GetK() * std)

4
market_hours_range.go
View file

@ -3,6 +3,8 @@ package chart
import (
"fmt"
"time"
"github.com/wcharczuk/go-chart/util"
)
// MarketHoursRange is a special type of range that compresses a time range into just the
@ -14,7 +16,7 @@ type MarketHoursRange struct {
MarketOpen time.Time
MarketClose time.Time
HolidayProvider HolidayProvider
HolidayProvider util.HolidayProvider
ValueFormatter ValueFormatter

6
roboto.go → roboto/roboto.go
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File diff suppressed because one or more lines are too long

0
util/generate.go → sequence/generate.go
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0
util/generate_test.go → sequence/generate_test.go
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0
util/sequence.go → sequence/sequence.go
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0
util/sequence_test.go → sequence/sequence_test.go
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141
sequence/time.go Normal file
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@ -0,0 +1,141 @@
package util
import (
"time"
"github.com/wcharczuk/go-chart/util"
)
// Time is a utility singleton with helper functions for time sequence generation.
var Time timeSequence
type timeSequence struct{}
// Days generates a sequence of timestamps by day, from -days to today.
func (ts timeSequence) Days(days int) []time.Time {
var values []time.Time
for day := days; day >= 0; day-- {
values = append(values, time.Now().AddDate(0, 0, -day))
}
return values
}
func (ts timeSequence) MarketHours(from, to time.Time, marketOpen, marketClose time.Time, isHoliday util.HolidayProvider) []time.Time {
var times []time.Time
cursor := util.Date.On(marketOpen, from)
toClose := util.Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
todayOpen := util.Date.On(marketOpen, cursor)
todayClose := util.Date.On(marketClose, cursor)
isValidTradingDay := !isHoliday(cursor) && util.Date.IsWeekDay(cursor.Weekday())
if (cursor.Equal(todayOpen) || cursor.After(todayOpen)) && (cursor.Equal(todayClose) || cursor.Before(todayClose)) && isValidTradingDay {
times = append(times, cursor)
}
if cursor.After(todayClose) {
cursor = util.Date.NextMarketOpen(cursor, marketOpen, isHoliday)
} else {
cursor = util.Date.NextHour(cursor)
}
}
return times
}
func (ts timeSequence) MarketHourQuarters(from, to time.Time, marketOpen, marketClose time.Time, isHoliday util.HolidayProvider) []time.Time {
var times []time.Time
cursor := util.Date.On(marketOpen, from)
toClose := util.Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
isValidTradingDay := !isHoliday(cursor) && util.Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
todayOpen := util.Date.On(marketOpen, cursor)
todayNoon := util.Date.NoonOn(cursor)
today2pm := util.Date.On(util.Date.Time(14, 0, 0, 0, cursor.Location()), cursor)
todayClose := util.Date.On(marketClose, cursor)
times = append(times, todayOpen, todayNoon, today2pm, todayClose)
}
cursor = util.Date.NextDay(cursor)
}
return times
}
func (ts timeSequence) MarketDayCloses(from, to time.Time, marketOpen, marketClose time.Time, isHoliday util.HolidayProvider) []time.Time {
var times []time.Time
cursor := util.Date.On(marketOpen, from)
toClose := util.Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
isValidTradingDay := !isHoliday(cursor) && util.Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
todayClose := util.Date.On(marketClose, cursor)
times = append(times, todayClose)
}
cursor = util.Date.NextDay(cursor)
}
return times
}
func (ts timeSequence) MarketDayAlternateCloses(from, to time.Time, marketOpen, marketClose time.Time, isHoliday util.HolidayProvider) []time.Time {
var times []time.Time
cursor := util.Date.On(marketOpen, from)
toClose := util.Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
isValidTradingDay := !isHoliday(cursor) && util.Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
todayClose := util.Date.On(marketClose, cursor)
times = append(times, todayClose)
}
cursor = cursor.AddDate(0, 0, 2)
}
return times
}
func (ts timeSequence) MarketDayMondayCloses(from, to time.Time, marketOpen, marketClose time.Time, isHoliday util.HolidayProvider) []time.Time {
var times []time.Time
cursor := util.Date.On(marketClose, from)
toClose := util.Date.On(marketClose, to)
for cursor.Equal(toClose) || cursor.Before(toClose) {
isValidTradingDay := !isHoliday(cursor) && util.Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
times = append(times, cursor)
}
cursor = util.Date.NextDayOfWeek(cursor, time.Monday)
}
return times
}
func (ts timeSequence) Hours(start time.Time, totalHours int) []time.Time {
times := make([]time.Time, totalHours)
last := start
for i := 0; i < totalHours; i++ {
times[i] = last
last = last.Add(time.Hour)
}
return times
}
// HoursFilled adds zero values for the data bounded by the start and end of the xdata array.
func (ts timeSequence) HoursFilled(xdata []time.Time, ydata []float64) ([]time.Time, []float64) {
start := util.Date.Start(xdata)
end := util.Date.End(xdata)
totalHours := util.Math.AbsInt(util.Date.DiffHours(start, end))
finalTimes := ts.Hours(start, totalHours+1)
finalValues := make([]float64, totalHours+1)
var hoursFromStart int
for i, xd := range xdata {
hoursFromStart = util.Date.DiffHours(start, xd)
finalValues[hoursFromStart] = ydata[i]
}
return finalTimes, finalValues
}

232
sequence/value_buffer.go Normal file
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@ -0,0 +1,232 @@
package util
import (
"fmt"
"strings"
util "github.com/wcharczuk/go-chart/util"
)
const (
valueBufferMinimumGrow = 4
valueBufferShrinkThreshold = 32
valueBufferGrowFactor = 200
valueBufferDefaultCapacity = 4
)
var (
emptyArray = make([]float64, 0)
)
// NewBuffer creates a new value buffer with an optional set of values.
func NewBuffer(values ...float64) *Buffer {
var tail int
array := make([]float64, util.Math.MaxInt(len(values), valueBufferDefaultCapacity))
if len(values) > 0 {
copy(array, values)
tail = len(values)
}
return &Buffer{
array: array,
head: 0,
tail: tail,
size: len(values),
}
}
// NewBufferWithCapacity creates a new ValueBuffer pre-allocated with the given capacity.
func NewBufferWithCapacity(capacity int) *Buffer {
return &Buffer{
array: make([]float64, capacity),
head: 0,
tail: 0,
size: 0,
}
}
// Buffer is a fifo datastructure that is backed by a pre-allocated array.
// Instead of allocating a whole new node object for each element, array elements are re-used (which saves GC churn).
// Enqueue can be O(n), Dequeue is generally O(1).
// Buffer implements `sequence.Provider`
type Buffer struct {
array []float64
head int
tail int
size int
}
// Len returns the length of the ValueBuffer (as it is currently populated).
// Actual memory footprint may be different.
func (b *Buffer) Len() int {
return b.size
}
// GetValue implements sequence provider.
func (b *Buffer) GetValue(index int) float64 {
effectiveIndex := (b.head + index) % len(b.array)
return b.array[effectiveIndex]
}
// Capacity returns the total size of the ValueBuffer, including empty elements.
func (b *Buffer) Capacity() int {
return len(b.array)
}
// SetCapacity sets the capacity of the ValueBuffer.
func (b *Buffer) SetCapacity(capacity int) {
newArray := make([]float64, capacity)
if b.size > 0 {
if b.head < b.tail {
arrayCopy(b.array, b.head, newArray, 0, b.size)
} else {
arrayCopy(b.array, b.head, newArray, 0, len(b.array)-b.head)
arrayCopy(b.array, 0, newArray, len(b.array)-b.head, b.tail)
}
}
b.array = newArray
b.head = 0
if b.size == capacity {
b.tail = 0
} else {
b.tail = b.size
}
}
// Clear removes all objects from the ValueBuffer.
func (b *Buffer) Clear() {
if b.head < b.tail {
arrayClear(b.array, b.head, b.size)
} else {
arrayClear(b.array, b.head, len(b.array)-b.head)
arrayClear(b.array, 0, b.tail)
}
b.head = 0
b.tail = 0
b.size = 0
}
// Enqueue adds an element to the "back" of the ValueBuffer.
func (b *Buffer) Enqueue(value float64) {
if b.size == len(b.array) {
newCapacity := int(len(b.array) * int(valueBufferGrowFactor/100))
if newCapacity < (len(b.array) + valueBufferMinimumGrow) {
newCapacity = len(b.array) + valueBufferMinimumGrow
}
b.SetCapacity(newCapacity)
}
b.array[b.tail] = value
b.tail = (b.tail + 1) % len(b.array)
b.size++
}
// Dequeue removes the first element from the RingBuffer.
func (b *Buffer) Dequeue() float64 {
if b.size == 0 {
return 0
}
removed := b.array[b.head]
b.head = (b.head + 1) % len(b.array)
b.size--
return removed
}
// Peek returns but does not remove the first element.
func (b *Buffer) Peek() float64 {
if b.size == 0 {
return 0
}
return b.array[b.head]
}
// PeekBack returns but does not remove the last element.
func (b *Buffer) PeekBack() float64 {
if b.size == 0 {
return 0
}
if b.tail == 0 {
return b.array[len(b.array)-1]
}
return b.array[b.tail-1]
}
// TrimExcess resizes the buffer to better fit the contents.
func (b *Buffer) TrimExcess() {
threshold := float64(len(b.array)) * 0.9
if b.size < int(threshold) {
b.SetCapacity(b.size)
}
}
// Array returns the ring buffer, in order, as an array.
func (b *Buffer) Array() Array {
newArray := make([]float64, b.size)
if b.size == 0 {
return newArray
}
if b.head < b.tail {
arrayCopy(b.array, b.head, newArray, 0, b.size)
} else {
arrayCopy(b.array, b.head, newArray, 0, len(b.array)-b.head)
arrayCopy(b.array, 0, newArray, len(b.array)-b.head, b.tail)
}
return Array(newArray)
}
// Each calls the consumer for each element in the buffer.
func (b *Buffer) Each(mapfn func(int, float64)) {
if b.size == 0 {
return
}
var index int
if b.head < b.tail {
for cursor := b.head; cursor < b.tail; cursor++ {
mapfn(index, b.array[cursor])
index++
}
} else {
for cursor := b.head; cursor < len(b.array); cursor++ {
mapfn(index, b.array[cursor])
index++
}
for cursor := 0; cursor < b.tail; cursor++ {
mapfn(index, b.array[cursor])
index++
}
}
}
// String returns a string representation for value buffers.
func (b *Buffer) String() string {
var values []string
for _, elem := range b.Array() {
values = append(values, fmt.Sprintf("%v", elem))
}
return strings.Join(values, " <= ")
}
// --------------------------------------------------------------------------------
// Util methods
// --------------------------------------------------------------------------------
func arrayClear(source []float64, index, length int) {
for x := 0; x < length; x++ {
absoluteIndex := x + index
source[absoluteIndex] = 0
}
}
func arrayCopy(source []float64, sourceIndex int, destination []float64, destinationIndex, length int) {
for x := 0; x < length; x++ {
from := sourceIndex + x
to := destinationIndex + x
destination[to] = source[from]
}
}

0
util/value_buffer_test.go → sequence/value_buffer_test.go
View file

137
util/time_series.go
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@ -1,137 +0,0 @@
package util
import "time"
// TimeSeries is a utility singleton with helper functions for time series generation.
var TimeSeries timeSeries
type timeSeries struct{}
// Days generates a sequence of timestamps by day, from -days to today.
func (ts timeSeries) Days(days int) []time.Time {
var values []time.Time
for day := days; day >= 0; day-- {
values = append(values, time.Now().AddDate(0, 0, -day))
}
return values
}
func (ts timeSeries) MarketHours(from, to time.Time, marketOpen, marketClose time.Time, isHoliday HolidayProvider) []time.Time {
var times []time.Time
cursor := Date.On(marketOpen, from)
toClose := Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
todayOpen := Date.On(marketOpen, cursor)
todayClose := Date.On(marketClose, cursor)
isValidTradingDay := !isHoliday(cursor) && Date.IsWeekDay(cursor.Weekday())
if (cursor.Equal(todayOpen) || cursor.After(todayOpen)) && (cursor.Equal(todayClose) || cursor.Before(todayClose)) && isValidTradingDay {
times = append(times, cursor)
}
if cursor.After(todayClose) {
cursor = Date.NextMarketOpen(cursor, marketOpen, isHoliday)
} else {
cursor = Date.NextHour(cursor)
}
}
return times
}
func (ts timeSeries) MarketHourQuarters(from, to time.Time, marketOpen, marketClose time.Time, isHoliday HolidayProvider) []time.Time {
var times []time.Time
cursor := Date.On(marketOpen, from)
toClose := Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
isValidTradingDay := !isHoliday(cursor) && Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
todayOpen := Date.On(marketOpen, cursor)
todayNoon := Date.NoonOn(cursor)
today2pm := Date.On(Date.Time(14, 0, 0, 0, cursor.Location()), cursor)
todayClose := Date.On(marketClose, cursor)
times = append(times, todayOpen, todayNoon, today2pm, todayClose)
}
cursor = Date.NextDay(cursor)
}
return times
}
func (ts timeSeries) MarketDayCloses(from, to time.Time, marketOpen, marketClose time.Time, isHoliday HolidayProvider) []time.Time {
var times []time.Time
cursor := Date.On(marketOpen, from)
toClose := Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
isValidTradingDay := !isHoliday(cursor) && Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
todayClose := Date.On(marketClose, cursor)
times = append(times, todayClose)
}
cursor = Date.NextDay(cursor)
}
return times
}
func (ts timeSeries) MarketDayAlternateCloses(from, to time.Time, marketOpen, marketClose time.Time, isHoliday HolidayProvider) []time.Time {
var times []time.Time
cursor := Date.On(marketOpen, from)
toClose := Date.On(marketClose, to)
for cursor.Before(toClose) || cursor.Equal(toClose) {
isValidTradingDay := !isHoliday(cursor) && Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
todayClose := Date.On(marketClose, cursor)
times = append(times, todayClose)
}
cursor = cursor.AddDate(0, 0, 2)
}
return times
}
func (ts timeSeries) MarketDayMondayCloses(from, to time.Time, marketOpen, marketClose time.Time, isHoliday HolidayProvider) []time.Time {
var times []time.Time
cursor := Date.On(marketClose, from)
toClose := Date.On(marketClose, to)
for cursor.Equal(toClose) || cursor.Before(toClose) {
isValidTradingDay := !isHoliday(cursor) && Date.IsWeekDay(cursor.Weekday())
if isValidTradingDay {
times = append(times, cursor)
}
cursor = Date.NextDayOfWeek(cursor, time.Monday)
}
return times
}
func (ts timeSeries) Hours(start time.Time, totalHours int) []time.Time {
times := make([]time.Time, totalHours)
last := start
for i := 0; i < totalHours; i++ {
times[i] = last
last = last.Add(time.Hour)
}
return times
}
// HoursFilled adds zero values for the data bounded by the start and end of the xdata array.
func (ts timeSeries) HoursFilled(xdata []time.Time, ydata []float64) ([]time.Time, []float64) {
start := Date.Start(xdata)
end := Date.End(xdata)
totalHours := Math.AbsInt(Date.DiffHours(start, end))
finalTimes := ts.Hours(start, totalHours+1)
finalValues := make([]float64, totalHours+1)
var hoursFromStart int
for i, xd := range xdata {
hoursFromStart = Date.DiffHours(start, xd)
finalValues[hoursFromStart] = ydata[i]
}
return finalTimes, finalValues
}

229
util/value_buffer.go
View file

@ -1,229 +0,0 @@
package util
import (
"fmt"
"strings"
)
const (
valueBufferMinimumGrow = 4
valueBufferShrinkThreshold = 32
valueBufferGrowFactor = 200
valueBufferDefaultCapacity = 4
)
var (
emptyArray = make([]float64, 0)
)
// NewValueBuffer creates a new value buffer with an optional set of values.
func NewValueBuffer(values ...float64) *ValueBuffer {
var tail int
array := make([]float64, Math.MaxInt(len(values), valueBufferDefaultCapacity))
if len(values) > 0 {
copy(array, values)
tail = len(values)
}
return &ValueBuffer{
array: array,
head: 0,
tail: tail,
size: len(values),
}
}
// NewValueBufferWithCapacity creates a new ValueBuffer pre-allocated with the given capacity.
func NewValueBufferWithCapacity(capacity int) *ValueBuffer {
return &ValueBuffer{
array: make([]float64, capacity),
head: 0,
tail: 0,
size: 0,
}
}
// ValueBuffer is a fifo buffer that is backed by a pre-allocated array, instead of allocating
// a whole new node object for each element (which saves GC churn).
// Enqueue can be O(n), Dequeue can be O(1).
type ValueBuffer struct {
array []float64
head int
tail int
size int
}
// Len returns the length of the ValueBuffer (as it is currently populated).
// Actual memory footprint may be different.
func (vb *ValueBuffer) Len() int {
return vb.size
}
// GetValue implements sequence provider.
func (vb *ValueBuffer) GetValue(index int) float64 {
effectiveIndex := (vb.head + index) % len(vb.array)
return vb.array[effectiveIndex]
}
// Capacity returns the total size of the ValueBuffer, including empty elements.
func (vb *ValueBuffer) Capacity() int {
return len(vb.array)
}
// SetCapacity sets the capacity of the ValueBuffer.
func (vb *ValueBuffer) SetCapacity(capacity int) {
newArray := make([]float64, capacity)
if vb.size > 0 {
if vb.head < vb.tail {
arrayCopy(vb.array, vb.head, newArray, 0, vb.size)
} else {
arrayCopy(vb.array, vb.head, newArray, 0, len(vb.array)-vb.head)
arrayCopy(vb.array, 0, newArray, len(vb.array)-vb.head, vb.tail)
}
}
vb.array = newArray
vb.head = 0
if vb.size == capacity {
vb.tail = 0
} else {
vb.tail = vb.size
}
}
// Clear removes all objects from the ValueBuffer.
func (vb *ValueBuffer) Clear() {
if vb.head < vb.tail {
arrayClear(vb.array, vb.head, vb.size)
} else {
arrayClear(vb.array, vb.head, len(vb.array)-vb.head)
arrayClear(vb.array, 0, vb.tail)
}
vb.head = 0
vb.tail = 0
vb.size = 0
}
// Enqueue adds an element to the "back" of the ValueBuffer.
func (vb *ValueBuffer) Enqueue(value float64) {
if vb.size == len(vb.array) {
newCapacity := int(len(vb.array) * int(valueBufferGrowFactor/100))
if newCapacity < (len(vb.array) + valueBufferMinimumGrow) {
newCapacity = len(vb.array) + valueBufferMinimumGrow
}
vb.SetCapacity(newCapacity)
}
vb.array[vb.tail] = value
vb.tail = (vb.tail + 1) % len(vb.array)
vb.size++
}
// Dequeue removes the first element from the RingBuffer.
func (vb *ValueBuffer) Dequeue() float64 {
if vb.size == 0 {
return 0
}
removed := vb.array[vb.head]
vb.head = (vb.head + 1) % len(vb.array)
vb.size--
return removed
}
// Peek returns but does not remove the first element.
func (vb *ValueBuffer) Peek() float64 {
if vb.size == 0 {
return 0
}
return vb.array[vb.head]
}
// PeekBack returns but does not remove the last element.
func (vb *ValueBuffer) PeekBack() float64 {
if vb.size == 0 {
return 0
}
if vb.tail == 0 {
return vb.array[len(vb.array)-1]
}
return vb.array[vb.tail-1]
}
// TrimExcess resizes the buffer to better fit the contents.
func (vb *ValueBuffer) TrimExcess() {
threshold := float64(len(vb.array)) * 0.9
if vb.size < int(threshold) {
vb.SetCapacity(vb.size)
}
}
// Array returns the ring buffer, in order, as an array.
func (vb *ValueBuffer) Array() Array {
newArray := make([]float64, vb.size)
if vb.size == 0 {
return newArray
}
if vb.head < vb.tail {
arrayCopy(vb.array, vb.head, newArray, 0, vb.size)
} else {
arrayCopy(vb.array, vb.head, newArray, 0, len(vb.array)-vb.head)
arrayCopy(vb.array, 0, newArray, len(vb.array)-vb.head, vb.tail)
}
return Array(newArray)
}
// Each calls the consumer for each element in the buffer.
func (vb *ValueBuffer) Each(mapfn func(int, float64)) {
if vb.size == 0 {
return
}
var index int
if vb.head < vb.tail {
for cursor := vb.head; cursor < vb.tail; cursor++ {
mapfn(index, vb.array[cursor])
index++
}
} else {
for cursor := vb.head; cursor < len(vb.array); cursor++ {
mapfn(index, vb.array[cursor])
index++
}
for cursor := 0; cursor < vb.tail; cursor++ {
mapfn(index, vb.array[cursor])
index++
}
}
}
// String returns a string representation for value buffers.
func (vb *ValueBuffer) String() string {
var values []string
for _, elem := range vb.Array() {
values = append(values, fmt.Sprintf("%v", elem))
}
return strings.Join(values, " <= ")
}
// --------------------------------------------------------------------------------
// Util methods
// --------------------------------------------------------------------------------
func arrayClear(source []float64, index, length int) {
for x := 0; x < length; x++ {
absoluteIndex := x + index
source[absoluteIndex] = 0
}
}
func arrayCopy(source []float64, sourceIndex int, destination []float64, destinationIndex, length int) {
for x := 0; x < length; x++ {
from := sourceIndex + x
to := destinationIndex + x
destination[to] = source[from]
}
}