machine: compute sha256 as we read the image file
It avoids to have the full file in memory.
[NO TESTS NEEDED]
package machine
import (
- "crypto/sha256"
- "io/ioutil"
url2 "net/url"
"os"
"path/filepath"
@@ -12,6 +10,7 @@ import (
"strings"
digest "github.com/opencontainers/go-digest"
+ "github.com/sirupsen/logrus"
)
// These should eventually be moved into machine/qemu as
@@ -95,12 +94,19 @@ func UpdateAvailable(d *Download) (bool, error) {
if _, err := os.Stat(d.LocalPath); os.IsNotExist(err) {
return false, nil
}
- b, err := ioutil.ReadFile(d.LocalPath)
+ fd, err := os.Open(d.LocalPath)
+ if err != nil {
+ return false, err
+ }
+ defer func() {
+ if err := fd.Close(); err != nil {
+ logrus.Error(err)
+ }
+ }()
+ sum, err := digest.SHA256.FromReader(fd)
if err != nil {
return false, err
}
- s := sha256.Sum256(b)
- sum := digest.NewDigestFromBytes(digest.SHA256, s[:])
return sum.Encoded() == d.Sha256sum, nil
}
