| // 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 |
| } |