// +build windows
 
 package distribution
 
 import (

 	"net/http"
 	"os"

 	"github.com/Sirupsen/logrus"

 	"github.com/docker/distribution"
 	"github.com/docker/distribution/context"

 	"github.com/docker/distribution/manifest/schema2"

 	"github.com/docker/distribution/registry/client/transport"

 )
 

 var _ distribution.Describable = &v2LayerDescriptor{}

 func (ld *v2LayerDescriptor) Descriptor() distribution.Descriptor {
 	if ld.src.MediaType == schema2.MediaTypeForeignLayer && len(ld.src.URLs) > 0 {
 		return ld.src
 	}
 	return distribution.Descriptor{}

 }
 
 func (ld *v2LayerDescriptor) open(ctx context.Context) (distribution.ReadSeekCloser, error) {

 	if len(ld.src.URLs) == 0 {

 		blobs := ld.repo.Blobs(ctx)
 		return blobs.Open(ctx, ld.digest)
 	}
 
 	var (
 		err error
 		rsc distribution.ReadSeekCloser
 	)
 
 	// Find the first URL that results in a 200 result code.

 	for _, url := range ld.src.URLs {

 		logrus.Debugf("Pulling %v from foreign URL %v", ld.digest, url)

 		rsc = transport.NewHTTPReadSeeker(http.DefaultClient, url, nil)
 		_, err = rsc.Seek(0, os.SEEK_SET)
 		if err == nil {
 			break
 		}

 		logrus.Debugf("Download for %v failed: %v", ld.digest, err)

 		rsc.Close()
 		rsc = nil
 	}
 	return rsc, err
 }