cteutil

type Storage interface {
	// If is first called, will open underlying storage. Otherwise will add ref count by one.
	OpenAndRef() error

	// Minus ref count by one, if ref count is zero, close underlying storage.
	DerefAndClose() (err error)

	// SwapData swaps data of two storage.
	// Other metainfo is not touched, such ref count/done flag etc.
	SwapData(other Storage) error

	// Reopen reset storage and related info.
	// So the status of Storage is like a new created one.
	Reopen() error

	// Add chunk into underlying storage.
	// Should return directly if chk is empty.
	Add(chk *chunk.Chunk) error

	// Get Chunk by index.
	GetChunk(chkIdx int) (*chunk.Chunk, error)

	// Get row by RowPtr.
	GetRow(ptr chunk.RowPtr) (chunk.Row, error)

	// NumChunks return chunk number of the underlying storage.
	NumChunks() int

	// NumRows return row number of the underlying storage.
	NumRows() int

	// Storage is not thread-safe.
	// By using Lock(), users can achieve the purpose of ensuring thread safety.
	Lock()
	Unlock()

	// Usually, Storage is filled first, then user can read it.
	// User can check whether Storage is filled first, if not, they can fill it.
	Done() bool
	SetDone()

	// Store error message, so we can return directly.
	Error() error
	SetError(err error)

	// Readers use iter information to determine
	// whether they need to read data from the beginning.
	SetIter(iter int)
	GetIter() int

	GetMemTracker() *memory.Tracker
	GetDiskTracker() *disk.Tracker
	ActionSpill() *chunk.SpillDiskAction
}

type StorageRC struct {
	// contains filtered or unexported fields
}