wings/internal/progress/progress.go

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2022-11-15 01:25:01 +00:00
package progress
import (
"io"
"strings"
"sync/atomic"
"github.com/pterodactyl/wings/system"
)
// Progress is used to track the progress of any I/O operation that are being
// performed.
type Progress struct {
// written is the total size of the files that have been written to the writer.
written uint64
// Total is the total size of the archive in bytes.
total uint64
// Writer .
Writer io.Writer
}
// NewProgress returns a new progress tracker for the given total size.
func NewProgress(total uint64) *Progress {
return &Progress{total: total}
}
// Written returns the total number of bytes written.
// This function should be used when the progress is tracking data being written.
func (p *Progress) Written() uint64 {
return atomic.LoadUint64(&p.written)
}
// Total returns the total size in bytes.
func (p *Progress) Total() uint64 {
return atomic.LoadUint64(&p.total)
}
// SetTotal sets the total size of the archive in bytes. This function is safe
// to call concurrently and can be used to update the total size if it changes,
// such as when the total size is simultaneously being calculated as data is
// being written through the progress writer.
func (p *Progress) SetTotal(total uint64) {
atomic.StoreUint64(&p.total, total)
}
// Write totals the number of bytes that have been written to the writer.
func (p *Progress) Write(v []byte) (int, error) {
n := len(v)
atomic.AddUint64(&p.written, uint64(n))
if p.Writer != nil {
return p.Writer.Write(v)
}
return n, nil
}
// Progress returns a formatted progress string for the current progress.
func (p *Progress) Progress(width int) string {
// current = 100 (Progress, dynamic)
// total = 1000 (Content-Length, dynamic)
// width = 25 (Number of ticks to display, static)
// widthPercentage = 100 / width (What percentage does each tick represent, static)
//
// percentageDecimal = current / total = 0.1
// percentage = percentageDecimal * 100 = 10%
// ticks = percentage / widthPercentage = 2.5
//
// ticks is a float64, so we cast it to an int which rounds it down to 2.
// Values are cast to floats to prevent integer division.
current := p.Written()
total := p.Total()
// width := is passed as a parameter
widthPercentage := float64(100) / float64(width)
percentageDecimal := float64(current) / float64(total)
percentage := percentageDecimal * 100
ticks := int(percentage / widthPercentage)
// Ensure that we never get a negative number of ticks, this will prevent strings#Repeat
// from panicking. A negative number of ticks is likely to happen when the total size is
// inaccurate, such as when we are going off of rough disk usage calculation.
if ticks < 0 {
ticks = 0
} else if ticks > width {
ticks = width
}
bar := strings.Repeat("=", ticks) + strings.Repeat(" ", width-ticks)
return "[" + bar + "] " + system.FormatBytes(current) + " / " + system.FormatBytes(total)
}