distribution: remove RootFSDownloadManager interface

This interface only had a single implementation (xfer.LayerDownloadManager),
and all places where it was used already imported the xfer package.
Removing the interface, also makes it a closer match to the "upload" part,
as `xfer.LayerUploadManager()` did not use an interface.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

builder/builder-next/adapters/containerimage/pull.go

@@ -22,7 +22,6 @@ import (
 	"github.com/containerd/containerd/remotes/docker/schema1"
 	distreference "github.com/docker/distribution/reference"
 	dimages "github.com/docker/docker/daemon/images"
-	"github.com/docker/docker/distribution"
 	"github.com/docker/docker/distribution/metadata"
 	"github.com/docker/docker/distribution/xfer"
 	"github.com/docker/docker/image"
@@ -52,7 +51,7 @@ type SourceOpt struct {
 	ContentStore    content.Store
 	CacheAccessor   cache.Accessor
 	ReferenceStore  reference.Store
-	DownloadManager distribution.RootFSDownloadManager
+	DownloadManager *xfer.LayerDownloadManager
 	MetadataStore   metadata.V2MetadataService
 	ImageStore      image.Store
 	RegistryHosts   docker.RegistryHosts

builder/builder-next/worker/worker.go

@@ -14,7 +14,6 @@ import (
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/rootfs"
 	"github.com/docker/docker/builder/builder-next/adapters/containerimage"
-	"github.com/docker/docker/distribution"
 	distmetadata "github.com/docker/docker/distribution/metadata"
 	"github.com/docker/docker/distribution/xfer"
 	"github.com/docker/docker/image"
@@ -70,7 +69,7 @@ type Opt struct {
 	ContentStore      content.Store
 	CacheManager      cache.Manager
 	ImageSource       *containerimage.Source
-	DownloadManager   distribution.RootFSDownloadManager
+	DownloadManager   *xfer.LayerDownloadManager
 	V2MetadataService distmetadata.V2MetadataService
 	Transport         nethttp.RoundTripper
 	Exporter          exporter.Exporter

daemon/images/service.go

@@ -11,7 +11,6 @@ import (
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/container"
 	daemonevents "github.com/docker/docker/daemon/events"
-	"github.com/docker/docker/distribution"
 	"github.com/docker/docker/distribution/metadata"
 	"github.com/docker/docker/distribution/xfer"
 	"github.com/docker/docker/image"
@@ -95,7 +94,7 @@ type ImageService struct {
 
 // DistributionServices provides daemon image storage services
 type DistributionServices struct {
-	DownloadManager   distribution.RootFSDownloadManager
+	DownloadManager   *xfer.LayerDownloadManager
 	V2MetadataService metadata.V2MetadataService
 	LayerStore        layer.Store
 	ImageStore        image.Store

distribution/config.go

@@ -56,7 +56,7 @@ type ImagePullConfig struct {
 	Config
 
 	// DownloadManager manages concurrent pulls.
-	DownloadManager RootFSDownloadManager
+	DownloadManager *xfer.LayerDownloadManager
 	// Schema2Types is the valid schema2 configuration types allowed
 	// by the pull operation.
 	Schema2Types []string
@@ -107,15 +107,6 @@ type PushLayer interface {
 	Release()
 }
 
-// RootFSDownloadManager handles downloading of the rootfs
-type RootFSDownloadManager interface {
-	// Download downloads the layers into the given initial rootfs and
-	// returns the final rootfs.
-	// Given progress output to track download progress
-	// Returns function to release download resources
-	Download(ctx context.Context, initialRootFS image.RootFS, os string, layers []xfer.DownloadDescriptor, progressOutput progress.Output) (image.RootFS, func(), error)
-}
-
 type imageConfigStore struct {
 	image.Store
 }