package handler import ( "context" "fmt" "io" "net/http" "strconv" "strings" "sync" "github.com/gorilla/mux" "github.com/nspcc-dev/neofs-s3-gw/api" "github.com/nspcc-dev/neofs-s3-gw/api/layer" "go.uber.org/zap" ) type ( detector struct { io.Writer sync.Once contentType string } ) func newDetector(w io.Writer) *detector { return &detector{Writer: w} } func (d *detector) Write(data []byte) (int, error) { d.Once.Do(func() { if rw, ok := d.Writer.(http.ResponseWriter); ok { rw.WriteHeader(http.StatusOK) } d.contentType = http.DetectContentType(data) }) return d.Writer.Write(data) } func (h *handler) contentTypeFetcher(ctx context.Context, w io.Writer, info *layer.ObjectInfo) (string, error) { return h.contentTypeFetcherWithRange(ctx, w, info, nil) } func (h *handler) contentTypeFetcherWithRange(ctx context.Context, w io.Writer, info *layer.ObjectInfo, rangeParams *layer.RangeParams) (string, error) { if info.IsDir() { if rangeParams != nil { return "", fmt.Errorf("it is forbidden to request for a range in the directory") } return info.ContentType, nil } writer := newDetector(w) params := &layer.GetObjectParams{ Bucket: info.Bucket, Object: info.Name, Writer: writer, Range: rangeParams, } // params.Length = inf.Size if err := h.obj.GetObject(ctx, params); err != nil { return "", err } return writer.contentType, nil } func fetchRangeHeader(headers http.Header, fullSize uint64) (*layer.RangeParams, error) { const prefix = "bytes=" rangeHeader := headers.Get("Range") if len(rangeHeader) == 0 { return nil, nil } if !strings.HasPrefix(rangeHeader, prefix) { return nil, fmt.Errorf("unknown unit in range header") } arr := strings.Split(strings.TrimPrefix(rangeHeader, prefix), "-") if len(arr) != 2 || (len(arr[0]) == 0 && len(arr[1]) == 0) { return nil, fmt.Errorf("unknown byte-range-set") } var end, start uint64 var err0, err1 error base, bitSize := 10, 64 if len(arr[0]) == 0 { end, err1 = strconv.ParseUint(arr[1], base, bitSize) start = fullSize - end end = fullSize - 1 } else if len(arr[1]) == 0 { start, err0 = strconv.ParseUint(arr[0], base, bitSize) end = fullSize - 1 } else { start, err0 = strconv.ParseUint(arr[0], base, bitSize) end, err1 = strconv.ParseUint(arr[1], base, bitSize) } if err0 != nil || err1 != nil || start > end { return nil, fmt.Errorf("invalid Range header") } return &layer.RangeParams{Start: start, End: end}, nil } func writeHeaders(h http.Header, info *layer.ObjectInfo) { h.Set("Content-Type", info.ContentType) h.Set("Last-Modified", info.Created.Format(http.TimeFormat)) h.Set("Content-Length", strconv.FormatInt(info.Size, 10)) for key, val := range info.Headers { h.Set("X-"+key, val) } } func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) { var ( err error inf *layer.ObjectInfo params *layer.RangeParams req = mux.Vars(r) bkt = req["bucket"] obj = req["object"] rid = api.GetRequestID(r.Context()) ) if inf, err = h.obj.GetObjectInfo(r.Context(), bkt, obj); err != nil { writeError(w, r, h.log, "could not find object", rid, bkt, obj, err) return } if params, err = fetchRangeHeader(r.Header, uint64(inf.Size)); err != nil { writeError(w, r, h.log, "could not parse range header", rid, bkt, obj, err) return } if inf.ContentType, err = h.contentTypeFetcherWithRange(r.Context(), w, inf, params); err != nil { writeError(w, r, h.log, "could not get object", rid, bkt, obj, err) return } writeHeaders(w.Header(), inf) if params != nil { writeRangeHeaders(w, params, inf.Size) } } func writeRangeHeaders(w http.ResponseWriter, params *layer.RangeParams, size int64) { w.Header().Set("Accept-Ranges", "bytes") w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", params.Start, params.End, size)) w.WriteHeader(http.StatusPartialContent) } func writeError(w http.ResponseWriter, r *http.Request, log *zap.Logger, msg, rid, bkt, obj string, err error) { log.Error(msg, zap.String("request_id", rid), zap.String("bucket_name", bkt), zap.String("object_name", obj), zap.Error(err)) api.WriteErrorResponse(r.Context(), w, api.Error{ Code: api.GetAPIError(api.ErrInternalError).Code, Description: err.Error(), HTTPStatusCode: http.StatusInternalServerError, }, r.URL) }