harbor/src/vendor/github.com/containerd/containerd/images/diffid.go

82 lines
2.4 KiB
Go

/*
Copyright The containerd Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package images
import (
"context"
"io"
"github.com/containerd/containerd/archive/compression"
"github.com/containerd/containerd/content"
"github.com/containerd/containerd/labels"
"github.com/opencontainers/go-digest"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/sirupsen/logrus"
)
// GetDiffID gets the diff ID of the layer blob descriptor.
func GetDiffID(ctx context.Context, cs content.Store, desc ocispec.Descriptor) (digest.Digest, error) {
switch desc.MediaType {
case
// If the layer is already uncompressed, we can just return its digest
MediaTypeDockerSchema2Layer,
ocispec.MediaTypeImageLayer,
MediaTypeDockerSchema2LayerForeign,
ocispec.MediaTypeImageLayerNonDistributable:
return desc.Digest, nil
}
info, err := cs.Info(ctx, desc.Digest)
if err != nil {
return "", err
}
v, ok := info.Labels[labels.LabelUncompressed]
if ok {
// Fast path: if the image is already unpacked, we can use the label value
return digest.Parse(v)
}
// if the image is not unpacked, we may not have the label
ra, err := cs.ReaderAt(ctx, desc)
if err != nil {
return "", err
}
defer ra.Close()
r := content.NewReader(ra)
uR, err := compression.DecompressStream(r)
if err != nil {
return "", err
}
defer uR.Close()
digester := digest.Canonical.Digester()
hashW := digester.Hash()
if _, err := io.Copy(hashW, uR); err != nil {
return "", err
}
if err := ra.Close(); err != nil {
return "", err
}
digest := digester.Digest()
// memorize the computed value
if info.Labels == nil {
info.Labels = make(map[string]string)
}
info.Labels[labels.LabelUncompressed] = digest.String()
if _, err := cs.Update(ctx, info, "labels"); err != nil {
logrus.WithError(err).Warnf("failed to set %s label for %s", labels.LabelUncompressed, desc.Digest)
}
return digest, nil
}