containerd/progress/bar.go
Stephen J Day 55a1b4eff8 cmd/dist: implement fetch prototype
With the rename of fetch to fetch-object, we now introduce the `fetch`
command. It will fetch all of the resources required for an image into
the content store. We'll still need to follow this up with metadata
registration but this is a good start.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-03-02 17:36:01 -08:00

65 lines
1.1 KiB
Go

package progress
import (
"bytes"
"fmt"
)
// TODO(stevvooe): We may want to support more interesting parameterization of
// the bar. For now, it is very simple.
// Bar provides a very simple progress bar implementation.
//
// Use with fmt.Printf and "r" to format the progress bar. A "-" flag makes it
// progress from right to left.
type Bar float64
var _ fmt.Formatter = Bar(1.0)
func (h Bar) Format(state fmt.State, r rune) {
switch r {
case 'r':
default:
panic(fmt.Sprintf("%v: unexpected format character", float64(h)))
}
if h > 1.0 {
h = 1.0
}
if h < 0.0 {
h = 0.0
}
if state.Flag('-') {
h = 1.0 - h
}
width, ok := state.Width()
if !ok {
// default width of 40
width = 40
}
var pad int
extra := len([]byte(green)) + len([]byte(reset))
p := make([]byte, width+extra)
p[0], p[len(p)-1] = '|', '|'
pad += 2
positive := int(Bar(width-pad) * h)
negative := width - pad - positive
n := 1
n += copy(p[n:], []byte(green))
n += copy(p[n:], bytes.Repeat([]byte("+"), positive))
n += copy(p[n:], []byte(reset))
if negative > 0 {
n += copy(p[n:len(p)-1], bytes.Repeat([]byte("-"), negative))
}
state.Write(p)
}