code: function size() {
  
              var sz = 0;
              this.struct.forEach(function (item) {
                  var type = item[1];
                  switch (type) {
                      case struct.Int8:
                      case struct.Uint8:
                          sz += 1;
                          break;
  
                      case struct.Int16:
                      case struct.Uint16:
                          sz += 2;
                          break;
  
                      case struct.Int32:
                      case struct.Uint32:
                      case struct.Fixed:
                          sz += 4;
                          break;
  
                      case struct.LongDateTime:
                          sz += 8;
                          break;
  
                      case struct.Bytes:
                          sz += item[2] || 0;
                          break;
  
                      case struct.Char:
                          sz += 1;
                          break;
  
                      case struct.String:
                          sz += item[2] || 0;
                          break;
  
                      default:
                          error.raise(10003, name, type);
                  }
              });
  
              return sz;
          }
docs: 获取ttf表的size大小
  
  @param {string} name 表名
  @return {number} 表大小