| package rootfs |
| |
| import ( |
| "fmt" |
| |
| "github.com/containerd/containerd/diff" |
| "github.com/containerd/containerd/mount" |
| "github.com/containerd/containerd/snapshot" |
| ocispec "github.com/opencontainers/image-spec/specs-go/v1" |
| "golang.org/x/net/context" |
| ) |
| |
| // Diff creates a layer diff for the given snapshot identifier from the parent |
| // of the snapshot. A content ref is provided to track the progress of the |
| // content creation and the provided snapshotter and mount differ are used |
| // for calculating the diff. The descriptor for the layer diff is returned. |
| func Diff(ctx context.Context, snapshotID string, sn snapshot.Snapshotter, d diff.Differ, opts ...diff.Opt) (ocispec.Descriptor, error) { |
| info, err := sn.Stat(ctx, snapshotID) |
| if err != nil { |
| return ocispec.Descriptor{}, err |
| } |
| |
| lowerKey := fmt.Sprintf("%s-parent-view", info.Parent) |
| lower, err := sn.View(ctx, lowerKey, info.Parent) |
| if err != nil { |
| return ocispec.Descriptor{}, err |
| } |
| defer sn.Remove(ctx, lowerKey) |
| |
| var upper []mount.Mount |
| if info.Kind == snapshot.KindActive { |
| upper, err = sn.Mounts(ctx, snapshotID) |
| if err != nil { |
| return ocispec.Descriptor{}, err |
| } |
| } else { |
| upperKey := fmt.Sprintf("%s-view", snapshotID) |
| upper, err = sn.View(ctx, upperKey, snapshotID) |
| if err != nil { |
| return ocispec.Descriptor{}, err |
| } |
| defer sn.Remove(ctx, lowerKey) |
| } |
| |
| return d.DiffMounts(ctx, lower, upper, opts...) |
| } |
