image/docker/archive/dest.go

82 lines
2.8 KiB
Go

package archive
import (
"context"
"io"
"github.com/containers/image/v5/docker/internal/tarfile"
"github.com/containers/image/v5/types"
"github.com/pkg/errors"
)
type archiveImageDestination struct {
*tarfile.Destination // Implements most of types.ImageDestination
ref archiveReference
archive *tarfile.Writer // Should only be closed if writer != nil
writer io.Closer // May be nil if the archive is shared
}
func newImageDestination(sys *types.SystemContext, ref archiveReference) (types.ImageDestination, error) {
if ref.sourceIndex != -1 {
return nil, errors.Errorf("Destination reference must not contain a manifest index @%d", ref.sourceIndex)
}
var archive *tarfile.Writer
var writer io.Closer
if ref.archiveWriter != nil {
archive = ref.archiveWriter
writer = nil
} else {
fh, err := openArchiveForWriting(ref.path)
if err != nil {
return nil, err
}
archive = tarfile.NewWriter(fh)
writer = fh
}
tarDest := tarfile.NewDestination(sys, archive, ref.ref)
if sys != nil && sys.DockerArchiveAdditionalTags != nil {
tarDest.AddRepoTags(sys.DockerArchiveAdditionalTags)
}
return &archiveImageDestination{
Destination: tarDest,
ref: ref,
archive: archive,
writer: writer,
}, nil
}
// DesiredLayerCompression indicates if layers must be compressed, decompressed or preserved
func (d *archiveImageDestination) DesiredLayerCompression() types.LayerCompression {
return types.Decompress
}
// Reference returns the reference used to set up this destination. Note that this should directly correspond to user's intent,
// e.g. it should use the public hostname instead of the result of resolving CNAMEs or following redirects.
func (d *archiveImageDestination) Reference() types.ImageReference {
return d.ref
}
// Close removes resources associated with an initialized ImageDestination, if any.
func (d *archiveImageDestination) Close() error {
if d.writer != nil {
return d.writer.Close()
}
return nil
}
// Commit marks the process of storing the image as successful and asks for the image to be persisted.
// unparsedToplevel contains data about the top-level manifest of the source (which may be a single-arch image or a manifest list
// if PutManifest was only called for the single-arch image with instanceDigest == nil), primarily to allow lookups by the
// original manifest list digest, if desired.
// WARNING: This does not have any transactional semantics:
// - Uploaded data MAY be visible to others before Commit() is called
// - Uploaded data MAY be removed or MAY remain around if Close() is called without Commit() (i.e. rollback is allowed but not guaranteed)
func (d *archiveImageDestination) Commit(ctx context.Context, unparsedToplevel types.UnparsedImage) error {
if d.writer != nil {
return d.archive.Close()
}
return nil
}