type Info struct {
	Digest       digest.Digest
	Size         int64     // layer size in bytes
	FetchedSize  int64     // layer fetched size in bytes
	PrefetchSize int64     // layer prefetch size in bytes
	ReadTime     time.Time // last time the layer was read
	TOCDigest    digest.Digest
}

type Layer interface {
	// Info returns the information of this layer.
	Info() Info

	// RootNode returns the root node of this layer.
	RootNode(baseInode uint32) (fusefs.InodeEmbedder, error)

	// Check checks if the layer is still connectable.
	Check() error

	// Refresh refreshes the layer connection.
	Refresh(ctx context.Context, hosts source.RegistryHosts, refspec reference.Spec, desc ocispec.Descriptor) error

	// Verify verifies this layer using the passed TOC Digest.
	// Nop if Verify() or SkipVerify() was already called.
	Verify(tocDigest digest.Digest) (err error)

	// SkipVerify skips verification for this layer.
	// Nop if Verify() or SkipVerify() was already called.
	SkipVerify()

	// Prefetch prefetches the specified size. If the layer is eStargz and contains landmark files,
	// the range indicated by these files is respected.
	Prefetch(prefetchSize int64) error

	// ReadAt reads this layer.
	ReadAt([]byte, int64, ...remote.Option) (int, error)

	// WaitForPrefetchCompletion waits untils Prefetch completes.
	WaitForPrefetchCompletion() error

	// BackgroundFetch fetches the entire layer contents to the cache.
	// Fetching contents is done as a background task.
	BackgroundFetch() error

	// Done releases the reference to this layer. The resources related to this layer will be
	// discarded sooner or later. Queries after calling this function won't be serviced.
	Done()
}

type OverlayOpaqueType int

const (
	OverlayOpaqueAll OverlayOpaqueType = iota
	OverlayOpaqueTrusted
	OverlayOpaqueUser
)

type Resolver struct {
	// contains filtered or unexported fields
}