forked from mirrors/docker-distribution
96 lines
2.1 KiB
Go
96 lines
2.1 KiB
Go
package testutil
|
|
|
|
import (
|
|
"archive/tar"
|
|
"bytes"
|
|
"crypto/rand"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
mrand "math/rand"
|
|
"time"
|
|
|
|
"github.com/docker/docker/pkg/tarsum"
|
|
)
|
|
|
|
// CreateRandomTarFile creates a random tarfile, returning it as an
|
|
// io.ReadSeeker along with its tarsum. An error is returned if there is a
|
|
// problem generating valid content.
|
|
func CreateRandomTarFile() (rs io.ReadSeeker, tarSum string, err error) {
|
|
nFiles := mrand.Intn(10) + 10
|
|
target := &bytes.Buffer{}
|
|
wr := tar.NewWriter(target)
|
|
|
|
// Perturb this on each iteration of the loop below.
|
|
header := &tar.Header{
|
|
Mode: 0644,
|
|
ModTime: time.Now(),
|
|
Typeflag: tar.TypeReg,
|
|
Uname: "randocalrissian",
|
|
Gname: "cloudcity",
|
|
AccessTime: time.Now(),
|
|
ChangeTime: time.Now(),
|
|
}
|
|
|
|
for fileNumber := 0; fileNumber < nFiles; fileNumber++ {
|
|
fileSize := mrand.Int63n(1<<20) + 1<<20
|
|
|
|
header.Name = fmt.Sprint(fileNumber)
|
|
header.Size = fileSize
|
|
|
|
if err := wr.WriteHeader(header); err != nil {
|
|
return nil, "", err
|
|
}
|
|
|
|
randomData := make([]byte, fileSize)
|
|
|
|
// Fill up the buffer with some random data.
|
|
n, err := rand.Read(randomData)
|
|
|
|
if n != len(randomData) {
|
|
return nil, "", fmt.Errorf("short read creating random reader: %v bytes != %v bytes", n, len(randomData))
|
|
}
|
|
|
|
if err != nil {
|
|
return nil, "", err
|
|
}
|
|
|
|
nn, err := io.Copy(wr, bytes.NewReader(randomData))
|
|
if nn != fileSize {
|
|
return nil, "", fmt.Errorf("short copy writing random file to tar")
|
|
}
|
|
|
|
if err != nil {
|
|
return nil, "", err
|
|
}
|
|
|
|
if err := wr.Flush(); err != nil {
|
|
return nil, "", err
|
|
}
|
|
}
|
|
|
|
if err := wr.Close(); err != nil {
|
|
return nil, "", err
|
|
}
|
|
|
|
reader := bytes.NewReader(target.Bytes())
|
|
|
|
// A tar builder that supports tarsum inline calculation would be awesome
|
|
// here.
|
|
ts, err := tarsum.NewTarSum(reader, true, tarsum.Version1)
|
|
if err != nil {
|
|
return nil, "", err
|
|
}
|
|
|
|
nn, err := io.Copy(ioutil.Discard, ts)
|
|
if nn != int64(len(target.Bytes())) {
|
|
return nil, "", fmt.Errorf("short copy when getting tarsum of random layer: %v != %v", nn, len(target.Bytes()))
|
|
}
|
|
|
|
if err != nil {
|
|
return nil, "", err
|
|
}
|
|
|
|
return bytes.NewReader(target.Bytes()), ts.Sum(nil), nil
|
|
}
|