resumablerecorder

type ReadableResumableRecorderMedium interface {
	io.Closer

	// 读取下一条记录
	Next(*ResumableRecord) error
}

type ResumableRecord struct {
	// 分片偏移量
	Offset uint64

	// 分片大小
	PartSize uint64

	// 分片写入量
	PartWritten uint64
}

type ResumableRecorder interface {
	// 打开记录仪介质以读取记录
	OpenForReading(*ResumableRecorderOpenArgs) ReadableResumableRecorderMedium

	// 打开记录仪介质以追加记录
	OpenForAppending(*ResumableRecorderOpenArgs) WriteableResumableRecorderMedium

	// 新建记录仪介质以追加记录
	OpenForCreatingNew(*ResumableRecorderOpenArgs) WriteableResumableRecorderMedium

	// 删除记录仪介质
	Delete(*ResumableRecorderOpenArgs) error

	// 清理过期的记录仪介质
	ClearOutdated(createdBefore time.Duration) error
}

type ResumableRecorderOpenArgs struct {
	// 数据源 ETag
	ETag string

	// 数据目标 ID
	DestinationID string

	// 分片大小
	PartSize uint64

	// 数据源大小
	TotalSize uint64

	// 数据源偏移量
	Offset uint64
}

type WriteableResumableRecorderMedium interface {
	io.Closer

	// 写入下一条记录
	Write(*ResumableRecord) error
}