Move storage package under registry package

Signed-off-by: Stephen J Day <stephen.day@docker.com>

docs/storage/registry.go

@@ -0,0 +1,80 @@
+package storage
+
+import (
+	"github.com/docker/distribution/storagedriver"
+	"golang.org/x/net/context"
+)
+
+// registry is the top-level implementation of Registry for use in the storage
+// package. All instances should descend from this object.
+type registry struct {
+	driver    storagedriver.StorageDriver
+	pm        *pathMapper
+	blobStore *blobStore
+}
+
+// NewRegistryWithDriver creates a new registry instance from the provided
+// driver. The resulting registry may be shared by multiple goroutines but is
+// cheap to allocate.
+func NewRegistryWithDriver(driver storagedriver.StorageDriver) Registry {
+	bs := &blobStore{}
+
+	reg := &registry{
+		driver:    driver,
+		blobStore: bs,
+
+		// TODO(sday): This should be configurable.
+		pm: defaultPathMapper,
+	}
+
+	reg.blobStore.registry = reg
+
+	return reg
+}
+
+// Repository returns an instance of the repository tied to the registry.
+// Instances should not be shared between goroutines but are cheap to
+// allocate. In general, they should be request scoped.
+func (reg *registry) Repository(ctx context.Context, name string) Repository {
+	return &repository{
+		ctx:      ctx,
+		registry: reg,
+		name:     name,
+	}
+}
+
+// repository provides name-scoped access to various services.
+type repository struct {
+	*registry
+	ctx  context.Context
+	name string
+}
+
+// Name returns the name of the repository.
+func (repo *repository) Name() string {
+	return repo.name
+}
+
+// Manifests returns an instance of ManifestService. Instantiation is cheap and
+// may be context sensitive in the future. The instance should be used similar
+// to a request local.
+func (repo *repository) Manifests() ManifestService {
+	return &manifestStore{
+		repository: repo,
+		revisionStore: &revisionStore{
+			repository: repo,
+		},
+		tagStore: &tagStore{
+			repository: repo,
+		},
+	}
+}
+
+// Layers returns an instance of the LayerService. Instantiation is cheap and
+// may be context sensitive in the future. The instance should be used similar
+// to a request local.
+func (repo *repository) Layers() LayerService {
+	return &layerStore{
+		repository: repo,
+	}
+}