distribution/docs/storage/cache/cache.go
Stephen J Day 812c8099a6 Decouple redis dependency from blob descriptor cache
Ensure that clients can use the blob descriptor cache provider without needing
the redis package.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-05-20 18:58:10 -07:00

36 lines
912 B
Go

// 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.Length < 0 {
return fmt.Errorf("cache: invalid length in descriptor: %v < 0", desc.Length)
}
if desc.MediaType == "" {
return fmt.Errorf("cache: empty mediatype on descriptor: %v", desc)
}
return nil
}