1 files changed, 35 insertions, 0 deletions
diff --git a/vendor/github.com/docker/distribution/registry/storage/cache/cache.go b/vendor/github.com/docker/distribution/registry/storage/cache/cache.go
new file mode 100644
index 000000000..10a390919
--- /dev/null
+++ b/vendor/github.com/docker/distribution/registry/storage/cache/cache.go
@@ -0,0 +1,35 @@
+// Package cache provides facilities to speed up access to the storage
+// backend.
+package cache
+
+import (
+	"fmt"
+
+	"github.com/docker/distribution"
+)
+
+// BlobDescriptorCacheProvider provides repository scoped
+// BlobDescriptorService cache instances and a global descriptor cache.
+type BlobDescriptorCacheProvider interface {
+	distribution.BlobDescriptorService
+
+	RepositoryScoped(repo string) (distribution.BlobDescriptorService, error)
+}
+
+// ValidateDescriptor provides a helper function to ensure that caches have
+// common criteria for admitting descriptors.
+func ValidateDescriptor(desc distribution.Descriptor) error {
+	if err := desc.Digest.Validate(); err != nil {
+		return err
+	}
+
+	if desc.Size < 0 {
+		return fmt.Errorf("cache: invalid length in descriptor: %v < 0", desc.Size)
+	}
+
+	if desc.MediaType == "" {
+		return fmt.Errorf("cache: empty mediatype on descriptor: %v", desc)
+	}
+
+	return nil
+}