package memory import ( "sync" "github.com/docker/distribution" "github.com/docker/distribution/context" "github.com/docker/distribution/digest" "github.com/docker/distribution/reference" "github.com/docker/distribution/registry/storage/cache" ) type inMemoryBlobDescriptorCacheProvider struct { global *mapBlobDescriptorCache repositories map[string]*mapBlobDescriptorCache mu sync.RWMutex } // NewInMemoryBlobDescriptorCacheProvider returns a new mapped-based cache for // storing blob descriptor data. func NewInMemoryBlobDescriptorCacheProvider() cache.BlobDescriptorCacheProvider { return &inMemoryBlobDescriptorCacheProvider{ global: newMapBlobDescriptorCache(), repositories: make(map[string]*mapBlobDescriptorCache), } } func (imbdcp *inMemoryBlobDescriptorCacheProvider) RepositoryScoped(canonicalName string) (distribution.BlobDescriptorService, error) { if _, err := reference.NewRepository(canonicalName); err != nil { return nil, err } imbdcp.mu.RLock() defer imbdcp.mu.RUnlock() return &repositoryScopedInMemoryBlobDescriptorCache{ repo: canonicalName, parent: imbdcp, repository: imbdcp.repositories[canonicalName], }, nil } func (imbdcp *inMemoryBlobDescriptorCacheProvider) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) { return imbdcp.global.Stat(ctx, dgst) } func (imbdcp *inMemoryBlobDescriptorCacheProvider) Clear(ctx context.Context, dgst digest.Digest) error { return imbdcp.global.Clear(ctx, dgst) } func (imbdcp *inMemoryBlobDescriptorCacheProvider) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error { _, err := imbdcp.Stat(ctx, dgst) if err == distribution.ErrBlobUnknown { if dgst.Algorithm() != desc.Digest.Algorithm() && dgst != desc.Digest { // if the digests differ, set the other canonical mapping if err := imbdcp.global.SetDescriptor(ctx, desc.Digest, desc); err != nil { return err } } // unknown, just set it return imbdcp.global.SetDescriptor(ctx, dgst, desc) } // we already know it, do nothing return err } // repositoryScopedInMemoryBlobDescriptorCache provides the request scoped // repository cache. Instances are not thread-safe but the delegated // operations are. type repositoryScopedInMemoryBlobDescriptorCache struct { repo string parent *inMemoryBlobDescriptorCacheProvider // allows lazy allocation of repo's map repository *mapBlobDescriptorCache } func (rsimbdcp *repositoryScopedInMemoryBlobDescriptorCache) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) { if rsimbdcp.repository == nil { return distribution.Descriptor{}, distribution.ErrBlobUnknown } return rsimbdcp.repository.Stat(ctx, dgst) } func (rsimbdcp *repositoryScopedInMemoryBlobDescriptorCache) Clear(ctx context.Context, dgst digest.Digest) error { if rsimbdcp.repository == nil { return distribution.ErrBlobUnknown } return rsimbdcp.repository.Clear(ctx, dgst) } func (rsimbdcp *repositoryScopedInMemoryBlobDescriptorCache) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error { if rsimbdcp.repository == nil { // allocate map since we are setting it now. rsimbdcp.parent.mu.Lock() var ok bool // have to read back value since we may have allocated elsewhere. rsimbdcp.repository, ok = rsimbdcp.parent.repositories[rsimbdcp.repo] if !ok { rsimbdcp.repository = newMapBlobDescriptorCache() rsimbdcp.parent.repositories[rsimbdcp.repo] = rsimbdcp.repository } rsimbdcp.parent.mu.Unlock() } if err := rsimbdcp.repository.SetDescriptor(ctx, dgst, desc); err != nil { return err } return rsimbdcp.parent.SetDescriptor(ctx, dgst, desc) } // mapBlobDescriptorCache provides a simple map-based implementation of the // descriptor cache. type mapBlobDescriptorCache struct { descriptors map[digest.Digest]distribution.Descriptor mu sync.RWMutex } var _ distribution.BlobDescriptorService = &mapBlobDescriptorCache{} func newMapBlobDescriptorCache() *mapBlobDescriptorCache { return &mapBlobDescriptorCache{ descriptors: make(map[digest.Digest]distribution.Descriptor), } } func (mbdc *mapBlobDescriptorCache) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) { if err := dgst.Validate(); err != nil { return distribution.Descriptor{}, err } mbdc.mu.RLock() defer mbdc.mu.RUnlock() desc, ok := mbdc.descriptors[dgst] if !ok { return distribution.Descriptor{}, distribution.ErrBlobUnknown } return desc, nil } func (mbdc *mapBlobDescriptorCache) Clear(ctx context.Context, dgst digest.Digest) error { mbdc.mu.Lock() defer mbdc.mu.Unlock() delete(mbdc.descriptors, dgst) return nil } func (mbdc *mapBlobDescriptorCache) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error { if err := dgst.Validate(); err != nil { return err } if err := cache.ValidateDescriptor(desc); err != nil { return err } mbdc.mu.Lock() defer mbdc.mu.Unlock() mbdc.descriptors[dgst] = desc return nil }