@@ -314,16 +314,25 @@ func postImagesCreate(srv *Server, version float64, w http.ResponseWriter, r *ht

 	tag := r.Form.Get("tag")

 	repo := r.Form.Get("repo")

+	if version > 1.0 {

+		w.Header().Set("Content-Type", "application/json")

+	}

+	sf := utils.NewStreamFormatter(version > 1.0)

 	if image != "" { //pull

 		registry := r.Form.Get("registry")

-		if version > 1.0 {

-			w.Header().Set("Content-Type", "application/json")

-		}

-		if err := srv.ImagePull(image, tag, registry, w, version > 1.0); err != nil {

+		if err := srv.ImagePull(image, tag, registry, w, sf); err != nil {

+			if sf.Used() {

+				w.Write(sf.FormatError(err))

+				return nil

+			}

 			return err

 		}

 	} else { //import

-		if err := srv.ImageImport(src, repo, tag, r.Body, w); err != nil {

+		if err := srv.ImageImport(src, repo, tag, r.Body, w, sf); err != nil {

+			if sf.Used() {

+				w.Write(sf.FormatError(err))

+				return nil

+			}

 			return err

 		}

 	}

@@ -359,10 +368,16 @@ func postImagesInsert(srv *Server, version float64, w http.ResponseWriter, r *ht

 		return fmt.Errorf("Missing parameter")

 	}

 	name := vars["name"]

-

-	imgId, err := srv.ImageInsert(name, url, path, w)

+	if version > 1.0 {

+		w.Header().Set("Content-Type", "application/json")

+	}

+	sf := utils.NewStreamFormatter(version > 1.0)

+	imgId, err := srv.ImageInsert(name, url, path, w, sf)

 	if err != nil {

-		return err

+		if sf.Used() {

+			w.Write(sf.FormatError(err))

+			return nil

+		}

 	}

 	b, err := json.Marshal(&ApiId{Id: imgId})

 	if err != nil {

@@ -382,8 +397,15 @@ func postImagesPush(srv *Server, version float64, w http.ResponseWriter, r *http

 		return fmt.Errorf("Missing parameter")

 	}

 	name := vars["name"]

-

-	if err := srv.ImagePush(name, registry, w); err != nil {

+	if version > 1.0 {

+		w.Header().Set("Content-Type", "application/json")

+	}

+	sf := utils.NewStreamFormatter(version > 1.0)

+	if err := srv.ImagePush(name, registry, w, sf); err != nil {

+		if sf.Used() {

+			w.Write(sf.FormatError(err))

+			return nil

+		}

 		return err

 	}

 	return nil

@@ -61,7 +61,7 @@ func (b *buildFile) CmdFrom(name string) error {

 				remote = name

 			}

-			if err := b.srv.ImagePull(remote, tag, "", b.out, false); err != nil {

+			if err := b.srv.ImagePull(remote, tag, "", b.out, utils.NewStreamFormatter(false)); err != nil {

 				return err

 			}

@@ -180,7 +180,8 @@ func (cli *DockerCli) CmdBuild(args ...string) error {

 			return err

 		} else {

 			// FIXME: Find a way to have a progressbar for the upload too

-			io.Copy(wField, utils.ProgressReader(ioutil.NopCloser(context), -1, os.Stdout, "Caching Context %v/%v (%v)\r", false))

+			sf := utils.NewStreamFormatter(false)

+			io.Copy(wField, utils.ProgressReader(ioutil.NopCloser(context), -1, os.Stdout, sf.FormatProgress("Caching Context", "%v/%v (%v)"), sf))

 		}

 		multipartBody = io.MultiReader(multipartBody, boundary)

 	}

@@ -1367,13 +1368,9 @@ func (cli *DockerCli) stream(method, path string, in io.Reader, out io.Writer) e

 	}

 	if resp.Header.Get("Content-Type") == "application/json" {

-		type Message struct {

-			Status   string `json:"status,omitempty"`

-			Progress string `json:"progress,omitempty"`

-		}

 		dec := json.NewDecoder(resp.Body)

 		for {

-			var m Message

+			var m utils.JsonMessage

 			if err := dec.Decode(&m); err == io.EOF {

 				break

 			} else if err != nil {

@@ -1381,6 +1378,8 @@ func (cli *DockerCli) stream(method, path string, in io.Reader, out io.Writer) e

 			}

 			if m.Progress != "" {

 				fmt.Fprintf(out, "Downloading %s\r", m.Progress)

+			} else if m.Error != "" {

+				return fmt.Errorf(m.Error)

 			} else {

 				fmt.Fprintf(out, "%s\n", m.Status)

 			}

@@ -15,10 +15,17 @@ Docker Remote API

 - Default port in the docker deamon is 4243 

 - The API tends to be REST, but for some complex commands, like attach or pull, the HTTP connection is hijacked to transport stdout stdin and stderr

-2. Endpoints

+2. Version

+==========

+

+The current verson of the API is 1.1

+Calling /images/<name>/insert is the same as calling /v1.1/images/<name>/insert

+You can still call an old version of the api using /v1.0/images/<name>/insert

+

+3. Endpoints

 ============

-2.1 Containers

+3.1 Containers

 --------------

 List containers

@@ -460,7 +467,7 @@ Remove a container

         :statuscode 500: server error

-2.2 Images

+3.2 Images

 ----------

 List Images

@@ -549,7 +556,19 @@ Create an image

            POST /images/create?fromImage=base HTTP/1.1

-        **Example response**:

+        **Example response v1.1**:

+

+        .. sourcecode:: http

+

+           HTTP/1.1 200 OK

+	   Content-Type: application/json

+

+	   {"status":"Pulling..."}

+	   {"progress":"1/? (n/a)"}

+	   {"error":"Invalid..."}

+	   ...

+

+        **Example response v1.0**:

         .. sourcecode:: http

@@ -580,7 +599,19 @@ Insert a file in a image

            POST /images/test/insert?path=/usr&url=myurl HTTP/1.1

-	**Example response**:

+	**Example response v1.1**:

+

+        .. sourcecode:: http

+

+           HTTP/1.1 200 OK

+	   Content-Type: application/json

+

+	   {"status":"Inserting..."}

+	   {"progress":"1/? (n/a)"}

+	   {"error":"Invalid..."}

+	   ...

+

+	**Example response v1.0**:

         .. sourcecode:: http

@@ -695,7 +726,19 @@ Push an image on the registry

 	    POST /images/test/push HTTP/1.1

-	 **Example response**:

+	 **Example response v1.1**:

+

+        .. sourcecode:: http

+

+           HTTP/1.1 200 OK

+	   Content-Type: application/json

+

+	   {"status":"Pushing..."}

+	   {"progress":"1/? (n/a)"}

+	   {"error":"Invalid..."}

+	   ...

+

+	 **Example response v1.0**:

         .. sourcecode:: http

@@ -801,7 +844,7 @@ Search images

 	   :statuscode 500: server error

-2.3 Misc

+3.3 Misc

 --------

 Build an image from Dockerfile via stdin

@@ -165,7 +165,8 @@ func (graph *Graph) TempLayerArchive(id string, compression Compression, output

 	if err != nil {

 		return nil, err

 	}

-	return NewTempArchive(utils.ProgressReader(ioutil.NopCloser(archive), 0, output, "Buffering to disk %v/%v (%v)", false), tmp.Root)

+	sf := utils.NewStreamFormatter(false)

+	return NewTempArchive(utils.ProgressReader(ioutil.NopCloser(archive), 0, output, sf.FormatProgress("Buffering to disk", "%v/%v (%v)"), sf), tmp.Root)

 }

 // Mktemp creates a temporary sub-directory inside the graph's filesystem.

@@ -68,7 +68,7 @@ func init() {

 		runtime: runtime,

 	}

 	// Retrieve the Image

-	if err := srv.ImagePull(unitTestImageName, "", "", os.Stdout, false); err != nil {

+	if err := srv.ImagePull(unitTestImageName, "", "", os.Stdout, utils.NewStreamFormatter(false)); err != nil {

 		panic(err)

 	}

 }

@@ -68,7 +68,7 @@ func (srv *Server) ImagesSearch(term string) ([]ApiSearch, error) {

 	return outs, nil

 }

-func (srv *Server) ImageInsert(name, url, path string, out io.Writer) (string, error) {

+func (srv *Server) ImageInsert(name, url, path string, out io.Writer, sf *utils.StreamFormatter) (string, error) {

 	out = utils.NewWriteFlusher(out)

 	img, err := srv.runtime.repositories.LookupImage(name)

 	if err != nil {

@@ -92,7 +92,7 @@ func (srv *Server) ImageInsert(name, url, path string, out io.Writer) (string, e

 		return "", err

 	}

-	if err := c.Inject(utils.ProgressReader(file.Body, int(file.ContentLength), out, "Downloading %v/%v (%v)\r", false), path); err != nil {

+	if err := c.Inject(utils.ProgressReader(file.Body, int(file.ContentLength), out, sf.FormatProgress("Downloading", "%v/%v (%v)"), sf), path); err != nil {

 		return "", err

 	}

 	// FIXME: Handle custom repo, tag comment, author

@@ -100,7 +100,7 @@ func (srv *Server) ImageInsert(name, url, path string, out io.Writer) (string, e

 	if err != nil {

 		return "", err

 	}

-	fmt.Fprintf(out, "%s\n", img.Id)

+	out.Write(sf.FormatStatus(img.Id))

 	return img.ShortId(), nil

 }

@@ -292,7 +292,7 @@ func (srv *Server) ContainerTag(name, repo, tag string, force bool) error {

 	return nil

 }

-func (srv *Server) pullImage(r *registry.Registry, out io.Writer, imgId, endpoint string, token []string, json bool) error {

+func (srv *Server) pullImage(r *registry.Registry, out io.Writer, imgId, endpoint string, token []string, sf *utils.StreamFormatter) error {

 	history, err := r.GetRemoteHistory(imgId, endpoint, token)

 	if err != nil {

 		return err

@@ -302,7 +302,7 @@ func (srv *Server) pullImage(r *registry.Registry, out io.Writer, imgId, endpoin

 	// FIXME: Launch the getRemoteImage() in goroutines

 	for _, id := range history {

 		if !srv.runtime.graph.Exists(id) {

-			fmt.Fprintf(out, utils.FormatStatus("Pulling %s metadata", json), id)

+			out.Write(sf.FormatStatus("Pulling %s metadata", id))

 			imgJson, err := r.GetRemoteImageJson(id, endpoint, token)

 			if err != nil {

 				// FIXME: Keep goging in case of error?

@@ -314,12 +314,12 @@ func (srv *Server) pullImage(r *registry.Registry, out io.Writer, imgId, endpoin

 			}

 			// Get the layer

-			fmt.Fprintf(out, utils.FormatStatus("Pulling %s fs layer", json), id)

+			out.Write(sf.FormatStatus("Pulling %s fs layer", id))

 			layer, contentLength, err := r.GetRemoteImageLayer(img.Id, endpoint, token)

 			if err != nil {

 				return err

 			}

-			if err := srv.runtime.graph.Register(utils.ProgressReader(layer, contentLength, out, utils.FormatProgress("%v/%v (%v)", json), json), false, img); err != nil {

+			if err := srv.runtime.graph.Register(utils.ProgressReader(layer, contentLength, out, sf.FormatProgress("Downloading", "%v/%v (%v)"), sf), false, img); err != nil {

 				return err

 			}

 		}

@@ -327,8 +327,8 @@ func (srv *Server) pullImage(r *registry.Registry, out io.Writer, imgId, endpoin

 	return nil

 }

-func (srv *Server) pullRepository(r *registry.Registry, out io.Writer, remote, askedTag string, json bool) error {

-	fmt.Fprintf(out, utils.FormatStatus("Pulling repository %s from %s", json), remote, auth.IndexServerAddress())

+func (srv *Server) pullRepository(r *registry.Registry, out io.Writer, remote, askedTag string, sf *utils.StreamFormatter) error {

+	out.Write(sf.FormatStatus("Pulling repository %s from %s", remote, auth.IndexServerAddress()))

 	repoData, err := r.GetRepositoryData(remote)

 	if err != nil {

 		return err

@@ -365,11 +365,11 @@ func (srv *Server) pullRepository(r *registry.Registry, out io.Writer, remote, a

 			utils.Debugf("(%s) does not match %s (id: %s), skipping", img.Tag, askedTag, img.Id)

 			continue

 		}

-		fmt.Fprintf(out, utils.FormatStatus("Pulling image %s (%s) from %s", json), img.Id, img.Tag, remote)

+		out.Write(sf.FormatStatus("Pulling image %s (%s) from %s", img.Id, img.Tag, remote))

 		success := false

 		for _, ep := range repoData.Endpoints {

-			if err := srv.pullImage(r, out, img.Id, "https://"+ep+"/v1", repoData.Tokens, json); err != nil {

-				fmt.Fprintf(out, utils.FormatStatus("Error while retrieving image for tag: %s (%s); checking next endpoint\n", json), askedTag, err)

+			if err := srv.pullImage(r, out, img.Id, "https://"+ep+"/v1", repoData.Tokens, sf); err != nil {

+				out.Write(sf.FormatStatus("Error while retrieving image for tag: %s (%s); checking next endpoint", askedTag, err))

 				continue

 			}

 			success = true

@@ -394,17 +394,17 @@ func (srv *Server) pullRepository(r *registry.Registry, out io.Writer, remote, a

 	return nil

 }

-func (srv *Server) ImagePull(name, tag, endpoint string, out io.Writer, json bool) error {

+func (srv *Server) ImagePull(name, tag, endpoint string, out io.Writer, sf *utils.StreamFormatter) error {

 	r := registry.NewRegistry(srv.runtime.root)

 	out = utils.NewWriteFlusher(out)

 	if endpoint != "" {

-		if err := srv.pullImage(r, out, name, endpoint, nil, json); err != nil {

+		if err := srv.pullImage(r, out, name, endpoint, nil, sf); err != nil {

 			return err

 		}

 		return nil

 	}

-	if err := srv.pullRepository(r, out, name, tag, json); err != nil {

+	if err := srv.pullRepository(r, out, name, tag, sf); err != nil {

 		return err

 	}

@@ -477,14 +477,14 @@ func (srv *Server) getImageList(localRepo map[string]string) ([]*registry.ImgDat

 	return imgList, nil

 }

-func (srv *Server) pushRepository(r *registry.Registry, out io.Writer, name string, localRepo map[string]string) error {

+func (srv *Server) pushRepository(r *registry.Registry, out io.Writer, name string, localRepo map[string]string, sf *utils.StreamFormatter) error {

 	out = utils.NewWriteFlusher(out)

-	fmt.Fprintf(out, "Processing checksums\n")

+	out.Write(sf.FormatStatus("Processing checksums"))

 	imgList, err := srv.getImageList(localRepo)

 	if err != nil {

 		return err

 	}

-	fmt.Fprintf(out, "Sending images list\n")

+	out.Write(sf.FormatStatus("Sending image list"))

 	repoData, err := r.PushImageJsonIndex(name, imgList, false)

 	if err != nil {

@@ -492,18 +492,18 @@ func (srv *Server) pushRepository(r *registry.Registry, out io.Writer, name stri

 	}

 	for _, ep := range repoData.Endpoints {

-		fmt.Fprintf(out, "Pushing repository %s to %s (%d tags)\r\n", name, ep, len(localRepo))

+		out.Write(sf.FormatStatus("Pushing repository %s to %s (%d tags)", name, ep, len(localRepo)))

 		// For each image within the repo, push them

 		for _, elem := range imgList {

 			if _, exists := repoData.ImgList[elem.Id]; exists {

-				fmt.Fprintf(out, "Image %s already on registry, skipping\n", name)

+				out.Write(sf.FormatStatus("Image %s already on registry, skipping", name))

 				continue

 			}

-			if err := srv.pushImage(r, out, name, elem.Id, ep, repoData.Tokens); err != nil {

+			if err := srv.pushImage(r, out, name, elem.Id, ep, repoData.Tokens, sf); err != nil {

 				// FIXME: Continue on error?

 				return err

 			}

-			fmt.Fprintf(out, "Pushing tags for rev [%s] on {%s}\n", elem.Id, ep+"/users/"+name+"/"+elem.Tag)

+			out.Write(sf.FormatStatus("Pushing tags for rev [%s] on {%s}", elem.Id, ep+"/users/"+name+"/"+elem.Tag))

 			if err := r.PushRegistryTag(name, elem.Id, elem.Tag, ep, repoData.Tokens); err != nil {

 				return err

 			}

@@ -516,13 +516,13 @@ func (srv *Server) pushRepository(r *registry.Registry, out io.Writer, name stri

 	return nil

 }

-func (srv *Server) pushImage(r *registry.Registry, out io.Writer, remote, imgId, ep string, token []string) error {

+func (srv *Server) pushImage(r *registry.Registry, out io.Writer, remote, imgId, ep string, token []string, sf *utils.StreamFormatter) error {

 	out = utils.NewWriteFlusher(out)

 	jsonRaw, err := ioutil.ReadFile(path.Join(srv.runtime.graph.Root, imgId, "json"))

 	if err != nil {

 		return fmt.Errorf("Error while retreiving the path for {%s}: %s", imgId, err)

 	}

-	fmt.Fprintf(out, "Pushing %s\r\n", imgId)

+	out.Write(sf.FormatStatus("Pushing %s", imgId))

 	// Make sure we have the image's checksum

 	checksum, err := srv.getChecksum(imgId)

@@ -537,7 +537,7 @@ func (srv *Server) pushImage(r *registry.Registry, out io.Writer, remote, imgId,

 	// Send the json

 	if err := r.PushImageJsonRegistry(imgData, jsonRaw, ep, token); err != nil {

 		if err == registry.ErrAlreadyExists {

-			fmt.Fprintf(out, "Image %s already uploaded ; skipping\n", imgData.Id)

+			out.Write(sf.FormatStatus("Image %s already uploaded ; skipping", imgData.Id))

 			return nil

 		}

 		return err

@@ -570,22 +570,22 @@ func (srv *Server) pushImage(r *registry.Registry, out io.Writer, remote, imgId,

 	}

 	// Send the layer

-	if err := r.PushImageLayerRegistry(imgData.Id, utils.ProgressReader(layerData, int(layerData.Size), out, "", false), ep, token); err != nil {

+	if err := r.PushImageLayerRegistry(imgData.Id, utils.ProgressReader(layerData, int(layerData.Size), out, sf.FormatProgress("", "%v/%v (%v)"), sf), ep, token); err != nil {

 		return err

 	}

 	return nil

 }

-func (srv *Server) ImagePush(name, endpoint string, out io.Writer) error {

+func (srv *Server) ImagePush(name, endpoint string, out io.Writer, sf *utils.StreamFormatter) error {

 	out = utils.NewWriteFlusher(out)

 	img, err := srv.runtime.graph.Get(name)

 	r := registry.NewRegistry(srv.runtime.root)

 	if err != nil {

-		fmt.Fprintf(out, "The push refers to a repository [%s] (len: %d)\n", name, len(srv.runtime.repositories.Repositories[name]))

+		out.Write(sf.FormatStatus("The push refers to a repository [%s] (len: %d)", name, len(srv.runtime.repositories.Repositories[name])))

 		// If it fails, try to get the repository

 		if localRepo, exists := srv.runtime.repositories.Repositories[name]; exists {

-			if err := srv.pushRepository(r, out, name, localRepo); err != nil {

+			if err := srv.pushRepository(r, out, name, localRepo, sf); err != nil {

 				return err

 			}

 			return nil

@@ -593,14 +593,14 @@ func (srv *Server) ImagePush(name, endpoint string, out io.Writer) error {

 		return err

 	}

-	fmt.Fprintf(out, "The push refers to an image: [%s]\n", name)

-	if err := srv.pushImage(r, out, name, img.Id, endpoint, nil); err != nil {

+	out.Write(sf.FormatStatus("The push refers to an image: [%s]", name))

+	if err := srv.pushImage(r, out, name, img.Id, endpoint, nil, sf); err != nil {

 		return err

 	}

 	return nil

 }

-func (srv *Server) ImageImport(src, repo, tag string, in io.Reader, out io.Writer) error {

+func (srv *Server) ImageImport(src, repo, tag string, in io.Reader, out io.Writer, sf *utils.StreamFormatter) error {

 	var archive io.Reader

 	var resp *http.Response

@@ -609,21 +609,21 @@ func (srv *Server) ImageImport(src, repo, tag string, in io.Reader, out io.Write

 	} else {

 		u, err := url.Parse(src)

 		if err != nil {

-			fmt.Fprintf(out, "Error: %s\n", err)

+			return err

 		}

 		if u.Scheme == "" {

 			u.Scheme = "http"

 			u.Host = src

 			u.Path = ""

 		}

-		fmt.Fprintf(out, "Downloading from %s\n", u)

+		out.Write(sf.FormatStatus("Downloading from %s", u))

 		// Download with curl (pretty progress bar)

 		// If curl is not available, fallback to http.Get()

 		resp, err = utils.Download(u.String(), out)

 		if err != nil {

 			return err

 		}

-		archive = utils.ProgressReader(resp.Body, int(resp.ContentLength), out, "Importing %v/%v (%v)\r", false)

+		archive = utils.ProgressReader(resp.Body, int(resp.ContentLength), out, sf.FormatProgress("Importing", "%v/%v (%v)"), sf)

 	}

 	img, err := srv.runtime.graph.Create(archive, nil, "Imported from "+src, "", nil)

 	if err != nil {

@@ -635,7 +635,7 @@ func (srv *Server) ImageImport(src, repo, tag string, in io.Reader, out io.Write

 			return err

 		}

 	}

-	fmt.Fprintf(out, "%s\n", img.ShortId())

+	out.Write(sf.FormatStatus(img.ShortId()))

 	return nil

 }

@@ -4,6 +4,7 @@ import (

 	"bytes"

 	"crypto/sha256"

 	"encoding/hex"

+	"encoding/json"

 	"errors"

 	"fmt"

 	"index/suffixarray"

@@ -69,7 +70,7 @@ type progressReader struct {

 	readProgress int           // How much has been read so far (bytes)

 	lastUpdate   int           // How many bytes read at least update

 	template     string        // Template to print. Default "%v/%v (%v)"

-	json         bool

+	sf *StreamFormatter

 }

 func (r *progressReader) Read(p []byte) (n int, err error) {

@@ -93,7 +94,7 @@ func (r *progressReader) Read(p []byte) (n int, err error) {

 	}

 	// Send newline when complete

 	if err != nil {

-		fmt.Fprintf(r.output, FormatStatus("", r.json))

+		r.output.Write(r.sf.FormatStatus(""))

 	}

 	return read, err

@@ -101,11 +102,12 @@ func (r *progressReader) Read(p []byte) (n int, err error) {

 func (r *progressReader) Close() error {

 	return io.ReadCloser(r.reader).Close()

 }

-func ProgressReader(r io.ReadCloser, size int, output io.Writer, template string, json bool) *progressReader {

-	if template == "" {

-		template = "%v/%v (%v)\r"

+func ProgressReader(r io.ReadCloser, size int, output io.Writer, template []byte, sf *StreamFormatter) *progressReader {

+      	tpl := string(template)

+	if tpl == "" {

+		tpl = string(sf.FormatProgress("", "%v/%v (%v)"))

 	}

-	return &progressReader{r, NewWriteFlusher(output), size, 0, 0, template, json}

+	return &progressReader{r, NewWriteFlusher(output), size, 0, 0, tpl, sf}

 }

 // HumanDuration returns a human-readable approximation of a duration

@@ -564,16 +566,57 @@ func NewWriteFlusher(w io.Writer) *WriteFlusher {

 	return &WriteFlusher{w: w, flusher: flusher}

 }

-func FormatStatus(str string, json bool) string {

-	if json {

-		return "{\"status\" : \"" + str + "\"}"

+type JsonMessage struct {

+	Status   string `json:"status,omitempty"`

+	Progress string `json:"progress,omitempty"`

+	Error    string `json:"error,omitempty"`

+}

+

+type StreamFormatter struct {

+	json bool

+	used bool

+}

+

+func NewStreamFormatter(json bool) *StreamFormatter {

+	return &StreamFormatter{json, false}

+}

+

+func (sf *StreamFormatter) FormatStatus(format string, a ...interface{}) []byte {

+	sf.used = true

+	str := fmt.Sprintf(format, a...)

+	if sf.json {

+		b, err := json.Marshal(&JsonMessage{Status:str});

+		if err != nil {

+			return sf.FormatError(err)

+		}

+		return b

 	}

-	return str + "\r\n"

+	return []byte(str + "\r\n")

 }

-func FormatProgress(str string, json bool) string {

-	if json {

-		return "{\"progress\" : \"" + str + "\"}"

+func (sf *StreamFormatter) FormatError(err error) []byte {

+	sf.used = true

+	if sf.json {

+		if b, err := json.Marshal(&JsonMessage{Error:err.Error()}); err == nil {

+			return b

+		}

+		return []byte("{\"error\":\"format error\"}")

 	}

-	return "Downloading " + str + "\r"

+	return []byte("Error: " + err.Error() + "\r\n")

+}

+

+func (sf *StreamFormatter) FormatProgress(action, str string) []byte {

+	sf.used = true

+	if sf.json {

+		b, err := json.Marshal(&JsonMessage{Progress:str})

+		if err != nil {

+                        return nil

+                }

+		return b

+	}

+	return []byte(action + " " + str + "\r")

+}

+

+func (sf *StreamFormatter) Used() bool {

+	return sf.used

 }