61 lines
1.1 KiB
Go
61 lines
1.1 KiB
Go
package progress
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
// Writer buffers writes until flush, at which time the last screen is cleared
|
|
// and the current buffer contents are written. This is useful for
|
|
// implementing progress displays, such as those implemented in docker and
|
|
// git.
|
|
type Writer struct {
|
|
buf bytes.Buffer
|
|
w io.Writer
|
|
lines int
|
|
}
|
|
|
|
func NewWriter(w io.Writer) *Writer {
|
|
return &Writer{
|
|
w: w,
|
|
}
|
|
}
|
|
|
|
func (w *Writer) Write(p []byte) (n int, err error) {
|
|
return w.buf.Write(p)
|
|
}
|
|
|
|
// Flush should be called when refreshing the current display.
|
|
func (w *Writer) Flush() error {
|
|
if w.buf.Len() == 0 {
|
|
return nil
|
|
}
|
|
|
|
if err := w.clear(); err != nil {
|
|
return err
|
|
}
|
|
|
|
w.lines = bytes.Count(w.buf.Bytes(), []byte("\n"))
|
|
|
|
if _, err := w.w.Write(w.buf.Bytes()); err != nil {
|
|
return err
|
|
}
|
|
|
|
w.buf.Reset()
|
|
return nil
|
|
}
|
|
|
|
// TODO(stevvooe): The following are system specific. Break these out if we
|
|
// decide to build this package further.
|
|
|
|
func (w *Writer) clear() error {
|
|
for i := 0; i < w.lines; i++ {
|
|
if _, err := fmt.Fprintf(w.w, "\x1b[0A\x1b[2K\r"); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|