示例#1
0
// handleProperty retrieves or deletes properties that can be added to a vertex or edge -- data posted
// or retrieved uses default compression
func (d *Data) handleProperty(ctx *datastore.VersionedCtx, db storage.GraphDB, w http.ResponseWriter, r *http.Request, path []string, method string) error {

	edgemode := false
	var propertyname string

	if len(path) == 3 {
		edgemode = true
		propertyname = path[2]
	} else if len(path) != 2 {
		return fmt.Errorf("Incorrect number of parameters specified for handling properties")
	} else {
		propertyname = path[1]
	}
	temp, err := strconv.Atoi(path[0])
	if err != nil {
		return fmt.Errorf("Vertex number not provided")
	}
	id1 := dvid.VertexID(temp)

	id2 := dvid.VertexID(0)
	if edgemode {
		temp, err := strconv.Atoi(path[1])
		if err != nil {
			return fmt.Errorf("Vertex number not provided")
		}
		id2 = dvid.VertexID(temp)
	}

	// remove a property from a vertex or edge
	if method == "delete" {
		if edgemode {
			db.RemoveEdgeProperty(ctx, id1, id2, propertyname)
			if err != nil {
				return fmt.Errorf("Failed to remove edge property %d-%d %s: %v\n", id1, id2, propertyname, err)
			}
		} else {
			db.RemoveVertexProperty(ctx, id1, propertyname)
			if err != nil {
				return fmt.Errorf("Failed to remove vertex property %d %s: %v\n", id1, propertyname, err)
			}
		}
	} else if method == "get" {
		var data []byte
		if edgemode {
			data, err = db.GetEdgeProperty(ctx, id1, id2, propertyname)
		} else {
			data, err = db.GetVertexProperty(ctx, id1, propertyname)
		}
		if err != nil {
			return fmt.Errorf("Failed to get property %s: %v\n", propertyname, err)
		}
		uncompress := true
		value, _, e := dvid.DeserializeData(data, uncompress)
		if e != nil {
			err = fmt.Errorf("Unable to deserialize data for property '%s': %v\n", propertyname, e.Error())
			return err
		}

		w.Header().Set("Content-Type", "application/octet-stream")
		_, err = w.Write(value)
		if err != nil {
			return err
		}
	} else if method == "post" {
		// read as binary and load into propertyname
		data, err := ioutil.ReadAll(r.Body)
		if err != nil {
			return err
		}
		serialization, err := dvid.SerializeData(data, d.Compression(), d.Checksum())
		if err != nil {
			return fmt.Errorf("Unable to serialize data: %v\n", err)
		}
		if edgemode {
			err = db.SetEdgeProperty(ctx, id1, id2, propertyname, serialization)
		} else {
			err = db.SetVertexProperty(ctx, id1, propertyname, serialization)
		}
		if err != nil {
			return fmt.Errorf("Failed to add property %s: %v\n", propertyname, err)
		}
	}

	return err
}