preallocate free space

Start with a clear and concise description of what problem you are trying to solve.

avoid that the insertion of entities in the database fails because there is no more free space in the device.

Describe the solution you'd like
allow objectbox to preallocate free space (during database creation) from device memory for further usage.

Describe alternatives you've considered
I don't give a damn about devices with little free space.

未指定文件、测试或入口点。首先检查数据库创建 API 以及设备存储耗尽时的行为；定义调用方如何请求预分配空间，以及如何验证之后成功插入实体。