func (p *v2Pusher) pushV2Layer(bs distribution.BlobService, l layer.Layer) (digest.Digest, error) {
out := p.config.OutStream
displayID := stringid.TruncateID(string(l.DiffID()))
out.Write(p.sf.FormatProgress(displayID, "Preparing", nil))
arch, err := l.TarStream()
if err != nil {
return "", err
}
// Send the layer
layerUpload, err := bs.Create(context.Background())
if err != nil {
return "", err
}
defer layerUpload.Close()
// don't care if this fails; best effort
size, _ := l.DiffSize()
reader := progressreader.New(progressreader.Config{
In: ioutil.NopCloser(arch), // we'll take care of close here.
Out: out,
Formatter: p.sf,
Size: size,
NewLines: false,
ID: displayID,
Action: "Pushing",
})
compressedReader := compress(reader)
digester := digest.Canonical.New()
tee := io.TeeReader(compressedReader, digester.Hash())
out.Write(p.sf.FormatProgress(displayID, "Pushing", nil))
nn, err := layerUpload.ReadFrom(tee)
compressedReader.Close()
if err != nil {
return "", err
}
dgst := digester.Digest()
if _, err := layerUpload.Commit(context.Background(), distribution.Descriptor{Digest: dgst}); err != nil {
return "", err
}
logrus.Debugf("uploaded layer %s (%s), %d bytes", l.DiffID(), dgst, nn)
out.Write(p.sf.FormatProgress(displayID, "Pushed", nil))
return dgst, nil
}
// getMaxMountAndExistenceCheckAttempts returns a maximum number of cross repository mount attempts from
// source repositories of target registry, maximum number of layer existence checks performed on the target
// repository and whether the check shall be done also with digests mapped to different repositories. The
// decision is based on layer size. The smaller the layer, the fewer attempts shall be made because the cost
// of upload does not outweigh a latency.
func getMaxMountAndExistenceCheckAttempts(layer layer.Layer) (maxMountAttempts, maxExistenceCheckAttempts int, checkOtherRepositories bool) {
size, err := layer.DiffSize()
switch {
// big blob
case size > middleLayerMaximumSize:
// 1st attempt to mount the blob few times
// 2nd few existence checks with digests associated to any repository
// then fallback to upload
return 4, 3, true
// middle sized blobs; if we could not get the size, assume we deal with middle sized blob
case size > smallLayerMaximumSize, err != nil:
// 1st attempt to mount blobs of average size few times
// 2nd try at most 1 existence check if there's an existing mapping to the target repository
// then fallback to upload
return 3, 1, false
// small blobs, do a minimum number of checks
default:
return 1, 1, false
}
}