func (vs *VolumeServer) DeleteHandler(w http.ResponseWriter, r *http.Request) {
	n := new(storage.Needle)
	vid, fid, _, _, _ := parseURLPath(r.URL.Path)
	volumeId, _ := storage.NewVolumeId(vid)
	n.ParsePath(fid)

	glog.V(2).Infoln("deleting", n)

	cookie := n.Cookie

	_, ok := vs.store.ReadVolumeNeedle(volumeId, n)
	if ok != nil {
		m := make(map[string]uint32)
		m["size"] = 0
		writeJsonQuiet(w, r, http.StatusNotFound, m)
		return
	}
	defer n.ReleaseMemory()

	if n.Cookie != cookie {
		glog.V(0).Infoln("delete", r.URL.Path, "with unmaching cookie from ", r.RemoteAddr, "agent", r.UserAgent())
		writeJsonError(w, r, http.StatusBadRequest, errors.New("File Random Cookie does not match."))
		return
	}

	count := int64(n.Size)

	if n.IsChunkedManifest() {
		chunkManifest, e := operation.LoadChunkManifest(n.Data, n.IsGzipped())
		if e != nil {
			writeJsonError(w, r, http.StatusInternalServerError, fmt.Errorf("Load chunks manifest error: %v", e))
			return
		}
		// make sure all chunks had deleted before delete manifest
		if e := chunkManifest.DeleteChunks(vs.GetMasterNode()); e != nil {
			writeJsonError(w, r, http.StatusInternalServerError, fmt.Errorf("Delete chunks error: %v", e))
			return
		}
		count = chunkManifest.Size
	}

	_, err := topology.ReplicatedDelete(vs.GetMasterNode(), vs.store, volumeId, n, r)

	if err == nil {
		m := make(map[string]int64)
		m["size"] = count
		writeJsonQuiet(w, r, http.StatusAccepted, m)
	} else {
		writeJsonError(w, r, http.StatusInternalServerError, fmt.Errorf("Deletion Failed: %v", err))
	}

}
//Experts only: takes multiple fid parameters. This function does not propagate deletes to replicas.
func (vs *VolumeServer) batchDeleteHandler(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()
	var ret []operation.DeleteResult
	for _, fid := range r.Form["fid"] {
		vid, id_cookie, err := operation.ParseFileId(fid)
		if err != nil {
			ret = append(ret, operation.DeleteResult{
				Fid:    fid,
				Status: http.StatusBadRequest,
				Error:  err.Error()})
			continue
		}
		n := new(storage.Needle)
		volumeId, _ := storage.NewVolumeId(vid)
		n.ParsePath(id_cookie)
		glog.V(4).Infoln("batch deleting", n)
		cookie := n.Cookie
		if _, err := vs.store.ReadVolumeNeedle(volumeId, n); err != nil {
			ret = append(ret, operation.DeleteResult{
				Fid:    fid,
				Status: http.StatusNotFound,
				Error:  err.Error(),
			})
			continue
		}

		if n.IsChunkedManifest() {
			ret = append(ret, operation.DeleteResult{
				Fid:    fid,
				Status: http.StatusNotAcceptable,
				Error:  "ChunkManifest: not allowed in batch delete mode.",
			})
			n.ReleaseMemory()
			continue
		}

		if n.Cookie != cookie {
			ret = append(ret, operation.DeleteResult{
				Fid:    fid,
				Status: http.StatusBadRequest,
				Error:  "File Random Cookie does not match.",
			})
			glog.V(0).Infoln("deleting", fid, "with unmaching cookie from ", r.RemoteAddr, "agent", r.UserAgent())
			n.ReleaseMemory()
			return
		}
		if size, err := vs.store.Delete(volumeId, n); err != nil {
			ret = append(ret, operation.DeleteResult{
				Fid:    fid,
				Status: http.StatusInternalServerError,
				Error:  err.Error()},
			)
		} else {
			ret = append(ret, operation.DeleteResult{
				Fid:    fid,
				Status: http.StatusAccepted,
				Size:   int(size)},
			)
		}
		n.ReleaseMemory()
	}

	writeJsonQuiet(w, r, http.StatusAccepted, ret)
}
func (vs *VolumeServer) GetOrHeadHandler(w http.ResponseWriter, r *http.Request) {
	n := new(storage.Needle)
	vid, fid, filename, ext, _ := parseURLPath(r.URL.Path)
	volumeId, err := storage.NewVolumeId(vid)
	if err != nil {
		glog.V(2).Infoln("parsing error:", err, r.URL.Path)
		w.WriteHeader(http.StatusBadRequest)
		return
	}
	err = n.ParsePath(fid)
	if err != nil {
		glog.V(2).Infoln("parsing fid error:", err, r.URL.Path)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	glog.V(4).Infoln("volume", volumeId, "reading", n)
	if !vs.store.HasVolume(volumeId) {
		if !vs.ReadRedirect {
			glog.V(2).Infoln("volume is not local:", err, r.URL.Path)
			w.WriteHeader(http.StatusNotFound)
			return
		}
		lookupResult, err := operation.Lookup(vs.GetMasterNode(), volumeId.String())
		glog.V(2).Infoln("volume", volumeId, "found on", lookupResult, "error", err)
		if err == nil && len(lookupResult.Locations) > 0 {
			u, _ := url.Parse(util.NormalizeUrl(lookupResult.Locations[0].PublicUrl))
			u.Path = r.URL.Path
			arg := url.Values{}
			if c := r.FormValue("collection"); c != "" {
				arg.Set("collection", c)
			}
			u.RawQuery = arg.Encode()
			http.Redirect(w, r, u.String(), http.StatusMovedPermanently)

		} else {
			glog.V(2).Infoln("lookup error:", err, r.URL.Path)
			w.WriteHeader(http.StatusNotFound)
		}
		return
	}
	cookie := n.Cookie
	count, e := vs.store.ReadVolumeNeedle(volumeId, n)
	glog.V(4).Infoln("read bytes", count, "error", e)
	if e != nil || count <= 0 {
		glog.V(0).Infoln("read error:", e, r.URL.Path)
		w.WriteHeader(http.StatusNotFound)
		return
	}
	defer n.ReleaseMemory()
	if n.Cookie != cookie {
		glog.V(0).Infoln("request", r.URL.Path, "with unmaching cookie seen:", cookie, "expected:", n.Cookie, "from", r.RemoteAddr, "agent", r.UserAgent())
		w.WriteHeader(http.StatusNotFound)
		return
	}
	if n.LastModified != 0 {
		w.Header().Set("Last-Modified", time.Unix(int64(n.LastModified), 0).UTC().Format(http.TimeFormat))
		if r.Header.Get("If-Modified-Since") != "" {
			if t, parseError := time.Parse(http.TimeFormat, r.Header.Get("If-Modified-Since")); parseError == nil {
				if t.Unix() >= int64(n.LastModified) {
					w.WriteHeader(http.StatusNotModified)
					return
				}
			}
		}
	}
	etag := n.Etag()
	if inm := r.Header.Get("If-None-Match"); inm == etag {
		w.WriteHeader(http.StatusNotModified)
		return
	}
	w.Header().Set("Etag", etag)

	if vs.tryHandleChunkedFile(n, filename, w, r) {
		return
	}

	if n.NameSize > 0 && filename == "" {
		filename = string(n.Name)
		if ext == "" {
			ext = path.Ext(filename)
		}
	}
	mtype := ""
	if n.MimeSize > 0 {
		mt := string(n.Mime)
		if !strings.HasPrefix(mt, "application/octet-stream") {
			mtype = mt
		}
	}

	if ext != ".gz" {
		if n.IsGzipped() {
			if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
				w.Header().Set("Content-Encoding", "gzip")
			} else {
				if n.Data, err = operation.UnGzipData(n.Data); err != nil {
					glog.V(0).Infoln("ungzip error:", err, r.URL.Path)
				}
			}
		}
	}
	if ext == ".png" || ext == ".jpg" || ext == ".gif" {
		width, height := 0, 0
		if r.FormValue("width") != "" {
			width, _ = strconv.Atoi(r.FormValue("width"))
		}
		if r.FormValue("height") != "" {
			height, _ = strconv.Atoi(r.FormValue("height"))
		}
		n.Data, _, _ = images.Resized(ext, n.Data, width, height)
	}

	if e := writeResponseContent(filename, mtype, bytes.NewReader(n.Data), w, r); e != nil {
		glog.V(2).Infoln("response write error:", e)
	}
}