137 lines
3.4 KiB
Go
137 lines
3.4 KiB
Go
package future
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/sha256"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"math/rand"
|
|
"net/http"
|
|
"time"
|
|
)
|
|
|
|
func Seed() {
|
|
rand.Seed(time.Now().UTC().UnixNano())
|
|
}
|
|
|
|
func ComputeId(content io.Reader) (string, error) {
|
|
h := sha256.New()
|
|
if _, err := io.Copy(h, content); err != nil {
|
|
return "", err
|
|
}
|
|
return fmt.Sprintf("%x", h.Sum(nil)[:8]), nil
|
|
}
|
|
|
|
func HumanDuration(d time.Duration) string {
|
|
if seconds := int(d.Seconds()); seconds < 1 {
|
|
return "Less than a second"
|
|
} else if seconds < 60 {
|
|
return fmt.Sprintf("%d seconds", seconds)
|
|
} else if minutes := int(d.Minutes()); minutes == 1 {
|
|
return "About a minute"
|
|
} else if minutes < 60 {
|
|
return fmt.Sprintf("%d minutes", minutes)
|
|
} else if hours := int(d.Hours()); hours == 1 {
|
|
return "About an hour"
|
|
} else if hours < 48 {
|
|
return fmt.Sprintf("%d hours", hours)
|
|
} else if hours < 24*7*2 {
|
|
return fmt.Sprintf("%d days", hours/24)
|
|
} else if hours < 24*30*3 {
|
|
return fmt.Sprintf("%d weeks", hours/24/7)
|
|
} else if hours < 24*365*2 {
|
|
return fmt.Sprintf("%d months", hours/24/30)
|
|
}
|
|
return fmt.Sprintf("%d years", d.Hours()/24/365)
|
|
}
|
|
|
|
func randomBytes() io.Reader {
|
|
return bytes.NewBuffer([]byte(fmt.Sprintf("%x", rand.Int())))
|
|
}
|
|
|
|
func RandomId() string {
|
|
id, _ := ComputeId(randomBytes()) // can't fail
|
|
return id
|
|
}
|
|
|
|
func Go(f func() error) chan error {
|
|
ch := make(chan error)
|
|
go func() {
|
|
ch <- f()
|
|
}()
|
|
return ch
|
|
}
|
|
|
|
// Pv wraps an io.Reader such that it is passed through unchanged,
|
|
// but logs the number of bytes copied (comparable to the unix command pv)
|
|
func Pv(src io.Reader, info io.Writer) io.Reader {
|
|
var totalBytes int
|
|
data := make([]byte, 2048)
|
|
r, w := io.Pipe()
|
|
go func() {
|
|
for {
|
|
if n, err := src.Read(data); err != nil {
|
|
w.CloseWithError(err)
|
|
return
|
|
} else {
|
|
totalBytes += n
|
|
fmt.Fprintf(info, "--> %d bytes\n", totalBytes)
|
|
if _, err = w.Write(data[:n]); err != nil {
|
|
return
|
|
}
|
|
}
|
|
}
|
|
}()
|
|
return r
|
|
}
|
|
|
|
// Request a given URL and return an io.Reader
|
|
func Download(url string, stderr io.Writer) (*http.Response, error) {
|
|
var resp *http.Response
|
|
var err error = nil
|
|
if resp, err = http.Get(url); err != nil {
|
|
return nil, err
|
|
}
|
|
if resp.StatusCode >= 400 {
|
|
return nil, errors.New("Got HTTP status code >= 400: " + resp.Status)
|
|
}
|
|
return resp, nil
|
|
}
|
|
|
|
// Reader with progress bar
|
|
type progressReader struct {
|
|
reader io.ReadCloser // Stream to read from
|
|
output io.Writer // Where to send progress bar to
|
|
read_total int // Expected stream length (bytes)
|
|
read_progress int // How much has been read so far (bytes)
|
|
last_update int // How many bytes read at least update
|
|
}
|
|
|
|
func (r *progressReader) Read(p []byte) (n int, err error) {
|
|
read, err := io.ReadCloser(r.reader).Read(p)
|
|
r.read_progress += read
|
|
|
|
// Only update progress for every 1% read
|
|
update_every := int(0.01 * float64(r.read_total))
|
|
if r.read_progress-r.last_update > update_every || r.read_progress == r.read_total {
|
|
fmt.Fprintf(r.output, "%d/%d (%.0f%%)\r",
|
|
r.read_progress,
|
|
r.read_total,
|
|
float64(r.read_progress)/float64(r.read_total)*100)
|
|
r.last_update = r.read_progress
|
|
}
|
|
// Send newline when complete
|
|
if err == io.EOF {
|
|
fmt.Fprintf(r.output, "\n")
|
|
}
|
|
|
|
return read, err
|
|
}
|
|
func (r *progressReader) Close() error {
|
|
return io.ReadCloser(r.reader).Close()
|
|
}
|
|
func ProgressReader(r io.ReadCloser, size int, output io.Writer) *progressReader {
|
|
return &progressReader{r, output, size, 0, 0}
|
|
}
|