Library to get progress feedback from io.Reader and io.Writer objects
To install, run go get github.com/bartmeuris/progressio
This package was created since most progress packages out-there seem to directly want to output stuff to a console mixing UI and work logic, work in a non-Go way (callback functions), or can only be used for specific scenario's like file downloads from the web.
This package provides wrappers around standard io.Reader and io.Writer objects which send back a progressio.Progress struct over a channel, so anything that uses standard io.Reader/io.Writer objects can give you progress feedback. It attempts to do all the heavy lifting for you:
- updates are throttled to 1 per 100ms (10 per second)
- Precalculates things (if possible) like:
- Speed in bytes/sec of the last few operations
- Average speed in bytes/sec since the start of the operation
- Remaining time
- Percentage
Some of these statistics are not available if the size was not specified up front.
type Progress struct {
Transferred int64 // Transferred data in bytes
TotalSize int64 // Total size of the transfer in bytes. <= 0 if size is unknown.
Percent float64 // If the size is known, the progress of the transfer in %
SpeedAvg int64 // Bytes/sec average over the entire transfer
Speed int64 // Bytes/sec of the last few reads/writes
Remaining time.Duration // Estimated time remaining, only available if the size is known.
StartTime time.Time // When the transfer was started
StopTime time.Time // only specified when the transfer is completed: when the transfer was stopped
}
The progressio.Progress object has at the moment only one function, the
String() function to return the string representation of the object.
import (
"io"
"github.com/bartmeuris/progressio"
)
// io.Copy wrapper to specify the size and show copy progress.
func copyProgress(w io.Writer, r io.Reader, size int64) (written int64, err error) {
// Wrap your io.Writer:
pw, ch := progressio.NewProgressWriter(w, size)
defer pw.Close()
// Launch a Go-Routine reading from the progress channel
go func() {
for p := range ch {
fmt.Printf("\rProgress: %s", p.String())
}
fmt.Printf("\nDone\n")
}
// Copy the data from the reader to the new writer
return io.Copy(pw, r)
}
- Add tests
- Clean up documentation
- Document byte/duration formatters
- Extract byte/duration formatters and place in separate library (?)